Sample records for unmarked plastic explosives

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

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...false Prohibitions relating to unmarked plastic explosives. 555.180 Section 555... COMMERCE IN EXPLOSIVES Marking of Plastic Explosives § 555.180 Prohibitions relating to unmarked plastic explosives. (a) No person...

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

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...true Prohibitions relating to unmarked plastic explosives. 555.180 Section 555... COMMERCE IN EXPLOSIVES Marking of Plastic Explosives § 555.180 Prohibitions relating to unmarked plastic explosives. (a) No person...

  3. Plastic explosives Mike Hopkins

    E-print Network

    Ravenel, Douglas

    Plastic explosives Mike Hill Mike Hopkins Doug Ravenel What this talk is about The poster The HHRH The reduced E4 -term 1.1 Plastic explosives: A C4 analog of the Kervaire invariant calculation Conference of Virginia Mike Hopkins Harvard University Doug Ravenel University of Rochester #12;Plastic explosives Mike

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

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...C2 H4 (NO3 )2 , molecular weight 152, when the minimum concentration...C6 H12 (NO2 )2 , molecular weight 176, when the minimum concentration...p-MNT), C7 H7 NO2 , molecular weight 137, when the minimum...

  5. 27 CFR 555.180 - Prohibitions relating to unmarked plastic explosives.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...C2 H4 (NO3 )2 , molecular weight 152, when the minimum concentration...C6 H12 (NO2 )2 , molecular weight 176, when the minimum concentration...p-MNT), C7 H7 NO2 , molecular weight 137, when the minimum...

  6. 27 CFR 555.180 - Prohibitions relating to unmarked plastic explosives.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...C2 H4 (NO3 )2 , molecular weight 152, when the minimum concentration...C6 H12 (NO2 )2 , molecular weight 176, when the minimum concentration...p-MNT), C7 H7 NO2 , molecular weight 137, when the minimum...

  7. 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.

  8. The Effect of Plasticity on Decoupling of Underground Explosions

    Microsoft Academic Search

    A. L. Latter; E. A. Martinelli; J. Mathews; W. G. McMillan

    1961-01-01

    The effect of plasticity, including work hardening, on seismic decoupling of under- ground explosions has been studied for large spherical cavities designed to give maximum de- coupling and for small (overdriven) cavities designed to give partial decoupling. An important result is that plasticity plays no role in explosions in large cavities, even those at great depth for which some plastic

  9. 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.

  10. Thermal decomposition models for HMX-based plastic bonded explosives

    Microsoft Academic Search

    Craig M. Tarver; Tri D. Tran

    2004-01-01

    Global multistep chemical kinetic models for the thermal decomposition of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazine (HMX)-based plastic bonded explosives (PBXs) using endothermic or exothermic binders are developed for calculation of the times to thermal explosion as functions of heating rate and geometry in the Chemical TOPAZ heat-transfer computer code. The decomposition mechanisms of the binder materials are treated separately from that of HMX, and

  11. Release isentropes of overdriven plastic-bonded explosive PBX9501

    Microsoft Academic Search

    R. S. Hixson; M. S. Shaw; J. N. Fritz; J. E. Vorthman; W. W. Anderson

    2000-01-01

    Continuous release isentropes for the plastic-bonded explosive PBX-9501 are obtained from velocity interferometer system for any reflector measurements at a high-explosive\\/LiF interface. Forward calculations from a tabular representation of the isentropes to the measured u(t) data at the interface are iterated to yield isentropes that give agreement with the data. Curves for the isentropes and for the isentropic gamma, ?S=?(?lnP\\/?lnV)S

  12. Release isentropes of overdriven plastic-bonded explosive PBX9501

    Microsoft Academic Search

    R. S. Hixson; M. S. Shaw; J. N. Fritz; J. E. Vorthman; W. W. Anderson

    2000-01-01

    Continuous release isentropes for the plastic-bonded explosive PBX-9501 are obtained from velocity interferometer system for any reflector measurements at a high-explosive\\/LiF interface. Forward calculations from a tabular representation of the isentropes to the measured u(t) data at the interface are iterated to yield isentropes that give agreement with the data. Curves for the isentropes and for the isentropic gamma, gammaS=-(?lnP\\/?lnV)S

  13. 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.

  14. 27 CFR 555.181 - Reporting of plastic explosives.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    All persons, other than an agency of the United States (including any military reserve component) or the National Guard of any State, possessing any plastic explosive on April 24, 1996, shall submit a report to the Director no later than August 22,...

  15. 27 CFR 555.181 - Reporting of plastic explosives.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    All persons, other than an agency of the United States (including any military reserve component) or the National Guard of any State, possessing any plastic explosive on April 24, 1996, shall submit a report to the Director no later than August 22,...

  16. 27 CFR 555.181 - Reporting of plastic explosives.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    All persons, other than an agency of the United States (including any military reserve component) or the National Guard of any State, possessing any plastic explosive on April 24, 1996, shall submit a report to the Director no later than August 22,...

  17. 27 CFR 555.181 - Reporting of plastic explosives.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    All persons, other than an agency of the United States (including any military reserve component) or the National Guard of any State, possessing any plastic explosive on April 24, 1996, shall submit a report to the Director no later than August 22,...

  18. 27 CFR 555.181 - Reporting of plastic explosives.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    All persons, other than an agency of the United States (including any military reserve component) or the National Guard of any State, possessing any plastic explosive on April 24, 1996, shall submit a report to the Director no later than August 22,...

  19. Detection of Plastic Explosive Traces in the Human Thermal Plume

    NASA Astrophysics Data System (ADS)

    Gowadia, Huban A.; Settles, Gary S.

    1998-11-01

    Aviation security requires the detection of explosive devices which terrorists, posing as passengers, may conceal beneath their clothing. Our goal is to understand the generation, transport, and collection of trace signals from such concealed explosives, which are found in the natural convective plume produced by the human body. Previous work (APS/DFD96, CG10) has visualized this plume and shown that concealed volatile explosives (e.g. TNT) produce a detectable vapor signal therein. Plastic explosives, on the other hand, have vanishingly low vapor pressures and are thus considered very difficult to detect. Present experiments use a dispersal chamber to collect and sample the plumes of human subjects wearing concealed gauze patches containing milligrams of RDX, the primary component of plastic explosives such as C-4. These experiments address the effects of agitation, clothing, temperature and humidity on trace detectability. Further experiments address the effects of oily vs. dry skin, contaminated clothing vs. gauze patches, and residual contamination left on skin previously in contact with RDX. The key role of airborne contaminated textile fibers is noted. Knowledge thus gained contributes to the design of an explosive detection portal for aviation security screening. (Research supported by FAA Grant 93-G-052.)

  20. Non-Shock Initiation Model for Plastic Bonded Explosive PBXN-5 and Cast Explosive: Experimental Results

    NASA Astrophysics Data System (ADS)

    Anderson, Mark; Todd, Steven; Caipen, Terry; Jensen, Charlie; Hughs, Chance

    2009-06-01

    A damage initiated reaction (DMGIR) computational model is being developed for the CTH shock physics code to predict the response of an explosive 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 reaction in the explosive, and its growth to detonation. The DMGIR model is a complement to the History Variable Reactive Burn (HVRB) model embedded in the current CTH code. Specifically designed experiments are supporting the development, implementation, and validation of the DMGIR numerical approach. PBXN-5 was the initial explosive material used experimentally to develop the DMGIR model. This explosive represents a family of plastically bonded explosives with good mechanical strength and rigid body properties. The model has been extended to cast explosives represented by Composition B. Furthermore, the DMGIR model will extended to predict results of non-shock mechanical insults for moldable plastic explosives such as C4 and PrimaSheet.

  1. Non-Shock Initiation Model for Plastic Bonded Explosive PBXN-5 and Cast Explosive

    NASA Astrophysics Data System (ADS)

    Todd, Steven; Caipen, Terry; Grady, Dennis; Anderson, Mark

    2009-06-01

    A damage initiated reaction (DMGIR) computational model is being developed for the CTH shock physics code to predict the response of an explosive 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 reaction in the explosive, and its growth to detonation. The DMGIR model is a complement to the History Variable Reactive Burn (HVRB) model embedded in the current CTH code. Specifically designed experiments are supporting the development, implementation, and validation of the DMGIR numerical approach. PBXN-5 was the initial explosive material used experimentally to develop the DMGIR model. This explosive represents a family of plastically bonded explosives with good mechanical strength and rigid body properties. The model has been extended to cast explosives represented by Composition B. Furthermore, the DMGIR model will extended to predict results of non-shock mechanical insults for moldable plastic explosives such as C4 and PrimaSheet.

  2. 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.

  3. 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 ?s. 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.

  4. Effects of Endothermic Binders on Times to Explosion of HMX- and TATB-Based Plastic Bonded Explosives

    Microsoft Academic Search

    Craig M. Tarver; Jake G. Koerner

    2007-01-01

    Plastic-bonded explosives (PBXs) based on octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) or 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) formulated with the endothermic binders Estane, Viton, or Kel-F exhibit longer times to thermal explosion than do pure HMX and TATB in the one-dimensional time to explosion (ODTX) and in other thermal experiments. Previous chemical kinetic thermal decomposition models for HMX- and TATB- based PBXs assumed that the binders decomposed

  5. 27 CFR 555.183 - Importation of plastic explosives on or after April 24, 1997.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    Persons filing Form 6 applications for the importation of plastic explosives on or after April 24, 1997, shall attach to the application the following written statement, prepared in triplicate, executed under the penalties of...

  6. 27 CFR 555.183 - Importation of plastic explosives on or after April 24, 1997.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    Persons filing Form 6 applications for the importation of plastic explosives on or after April 24, 1997, shall attach to the application the following written statement, prepared in triplicate, executed under the penalties of...

  7. 27 CFR 555.183 - Importation of plastic explosives on or after April 24, 1997.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    Persons filing Form 6 applications for the importation of plastic explosives on or after April 24, 1997, shall attach to the application the following written statement, prepared in triplicate, executed under the penalties of...

  8. 27 CFR 555.183 - Importation of plastic explosives on or after April 24, 1997.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    Persons filing Form 6 applications for the importation of plastic explosives on or after April 24, 1997, shall attach to the application the following written statement, prepared in triplicate, executed under the penalties of...

  9. 27 CFR 555.183 - Importation of plastic explosives on or after April 24, 1997.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    Persons filing Form 6 applications for the importation of plastic explosives on or after April 24, 1997, shall attach to the application the following written statement, prepared in triplicate, executed under the penalties of...

  10. The interaction of an underwater explosion bubble and an elastic–plastic structure

    Microsoft Academic Search

    A. M. Zhang; X. L. Yao; J. Li

    2008-01-01

    Based on the potential flow theory, the boundary element method (BEM) is applied to calculate the dynamics of an underwater explosion bubble near boundaries, and in conjunction with the finite element method (FEM) it is employed to compute the interaction between a bubble and an elastic–plastic structure. A complete 3D underwater explosion bubble dynamics code is developed; the simulated results

  11. Plastic explosive RDX: Cyclotrimethylenetrinitramine. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    NONE

    1995-10-01

    The bibliography contains citations concerning the properties and handling of plastics explosive RDX. Production, decomposition, toxicology studies, and desensitizing techniques are discussed. RDX detection in munitions plant wastewater and air samples is described along with methods of eliminating this explosive from the effluent. Molecular dynamics, sensitivity to shock and heat, burning behavior, and explosion velocity are presented. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  12. Plastic explosive RDX: Cyclotrimethylenetrinitramine. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    NONE

    1996-12-01

    The bibliography contains citations concerning the properties and handling of plastics explosive RDX. Production, decomposition, toxicology studies, and desensitizing techniques are discussed. RDX detection in munitions plant wastewater and air samples is described along with methods of eliminating this explosive from the effluent. Molecular dynamics, sensitivity to shock and heat, burning behavior, and explosion velocity are presented. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  13. Non-Shock Initiation Model for Plastic Bonded Explosive PBXN-5 and Cast Explosive: Experimental Results

    Microsoft Academic Search

    Mark Anderson; Steven Todd; Terry Caipen; Charlie Jensen; Chance Hughs

    2009-01-01

    A damage initiated reaction (DMGIR) computational model is being developed for the CTH shock physics code to predict the response of an explosive 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 reaction in the explosive, and its growth to detonation. The

  14. Non-Shock Initiation Model for Plastic Bonded Explosive PBXN-5 and Cast Explosive

    Microsoft Academic Search

    Steven Todd; Terry Caipen; Dennis Grady; Mark Anderson

    2009-01-01

    A damage initiated reaction (DMGIR) computational model is being developed for the CTH shock physics code to predict the response of an explosive 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 reaction in the explosive, and its growth to detonation. The

  15. 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. [West Texas A and M Univ., Canyon, TX (United States); Rainwater, K.A. [Texas Tech Univ., Lubbock, TX (United States); Lightfoot, J.M. [Pantex Plant, Amarillo, TX (United States); Richardson, B.R. [Engineered Carbons, Inc., Borger, TX (United States)

    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.

  16. 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)

  17. Plastic bonded explosive (PBX) particle size distribution (PSD) measurements using an image analysis system

    Microsoft Academic Search

    Gregg Kent Sullivan

    2003-01-01

    The slurry process for producing plastic bonded explosives (PBX) has been used for many years. However, until recently the mechanisms involved have not been studied quantitatively to determine the effects of the various control variables. Recently, the effects of operating variables on the final product have been studied; however, no attempt was made to measure particle growth during the slurry

  18. Quantification of reaction violence and combustion enthalpy of plastic bonded explosive 9501 under strong confinement

    NASA Astrophysics Data System (ADS)

    Perry, W. Lee; Dickson, Peter M.; Parker, Gary R.; Asay, B. W.

    2005-01-01

    The confinement experienced by an explosive during thermal self-initiation can substantially affect performance in terms of deflagration-to-detonation characteristics and explosion/detonation violence. To this end, we have developed an experiment to quantitatively observe enthalpy change and reaction violence in thermally initiated plastic bonded explosive (PBX) 9501. Traditionally, researchers attempt to quantify violence using terminal observations of fragment size, fragment velocity, and through subjective observations. In the work presented here, the explosive was loaded into a heated gun assembly where we subjected a 300 mg charge to a cook-off schedule and a range of static and inertial confinements. Static confinement was controlled using rupture disks calibrated at 34.5 and 138 MPa. The use of 3.15 and 6.3 g projectile masses provided a variation in inertial confinement. This was a regime of strong confinement; a significant fraction of the explosive energy was required to rupture the disk, and the projectile mass was large compared to the charge mass. The state variables pressure and volume were measured in the breech. From these data, we quantified both the reaction enthalpy change and energy release rate of the explosive on a microsecond time scale using a thermodynamic analyisis. We used these values to unambiguously quantify explosion violence as a function of confinement at a fixed cook-off schedule of 190 C for 1 h. P2?, a measure of critical shock energy required for shock ignition of an adjacent explosive was also computed. We found variations in this confinement regime to have a weak effect on enthalpy change, power, violence and shock energy. Violence was approximately 100 times lower than detonating trinitrotoluene, but the measured shock energy approached the critical shock energy for initiating secondary high explosives.

  19. 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.

  20. 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.

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

    SciTech Connect

    Hoffman, D.M. [Lawrence Livermore National Lab., CA (United States); Hawkins, T.W. [Phillips Lab., Edwards AFB, CA (United States); Lindsay, G.A. [Naval Weapons Station, China Lake, CA (United States)] [and others

    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.

  2. Explosives

    SciTech Connect

    Meyer, R.

    1986-01-01

    ''Explosives'' is a handbook covering the entire field of explosives. The book contains about 500 entries arranged in alphabetical order. These include formulas and descriptions of about 120 explosive chemicals, 60 additives, fuels, oxidizing agents and a 1500-entry subject index. The properties, manufacturing methods and applications of each substance are briefly described. In the case of key explosives and raw materials, the standard purity specifications are also listed.

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

    SciTech Connect

    Hooks, Daniel E [Los Alamos National Laboratory; Morris, John S [Los Alamos National Laboratory; Hill, Larry G [Los Alamos National Laboratory; Francois, Elizabeth [Los Alamos National Laboratory

    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.

  4. 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

  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. Non-Shock Initiation Model for Plastic Bonded Explosive PBXN-5: Theoretical Results

    Microsoft Academic Search

    S. N. Todd; T. J. Vogler; T. L. Caipen; D. E. Grady

    2007-01-01

    A ``damage-initiated reaction'' (DMGIR) computational model is presented for prediction of explosive response 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 reaction in the explosive, and the growth to detonation. The DMGIR model was embedded into an existing shock-physics computational code

  7. NON-SHOCK INITIATION MODEL FOR PLASTIC BONDED EXPLOSIVE PBXN-5: THEORETICAL RESULTS

    Microsoft Academic Search

    S. N. Todd; T. J. Vogler; T. L. Caipen; D. E. Grady

    2007-01-01

    A “damage-initiated reaction” (DMGIR) computational model is presented for prediction of explosive response 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 reaction in the explosive, and the growth to detonation. The DMGIR model was embedded into an existing shock-physics computational code

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

    SciTech Connect

    Gustavsen, Richard L [Los Alamos National Laboratory; Bartram, Brian D [Los Alamos National Laboratory; Sanchez, Nathaniel (nate) J [Los Alamos National Laboratory

    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.

  9. Interaction of underwater explosion bubble with complex elastic-plastic structure

    Microsoft Academic Search

    A.-man Zhang; Xiong-liang Yao

    2008-01-01

    Considering the elastic-plasticity of the structure, the combination of boundary element method and finite element method\\u000a (FEM) is employed to present the calculation method for solving the complex coupled dynamic problem of bubble, elastic-plastic\\u000a structure and the free surface, and the complete three-dimensional calculation program is developed as well. The error between\\u000a the calculated result and the experimental result is

  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. Pedestrians' crossing behaviors and safety at unmarked roadway in China.

    PubMed

    Zhuang, Xiangling; Wu, Changxu

    2011-11-01

    Pedestrians' crossing out of crosswalks (unmarked roadway) contributed to many traffic accidents, but existing pedestrian studies mainly focus on crosswalk crossing in developed countries specifically. Field observation of 254 pedestrians at unmarked roadway in China showed that 65.7% of them did not look for vehicles after arriving at the curb. Those who did look and pay attention to the traffic did so for duration of time that followed an exponential distribution. Pedestrians preferred crossing actively in tentative ways rather than waiting passively. The waiting time at the curb, at the median, and at the roadway all followed exponential distributions. During crossing, all pedestrians looked at the oncoming vehicles. When interacting with these vehicles, 31.9% of them ran and 11.4% stepped backwards. Running pedestrians usually began running at the borderline rather than within the lanes. Pedestrians preferred safe to short paths and they crossed second half of the road with significantly higher speed. These behavioral patterns were rechecked at an additional site with 105 pedestrians and the results showed much accordance. In terms of safety, pedestrians who were middle aged, involved in bigger groups, looked at vehicles more often before crossing or interacted with buses rather than cars were safer while those running were more dangerous. Potential applications of these findings, including building accurate simulation models of pedestrians and education of drivers and pedestrians in developing countries were also discussed. PMID:21819820

  12. Explosive simulants for testing explosive detection systems

    Microsoft Academic Search

    J. W. Kury; B. L. Anderson

    1999-01-01

    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.

  13. Explosive simulants for testing explosive detection systems

    DOEpatents

    Kury, John W. (Danville, CA); Anderson, Brian L. (Lodi, CA)

    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. Modeling structured population dynamics using data from unmarked individuals.

    PubMed

    Zipkin, Elise F; Thorson, James T; See, Kevin; Lynch, Heather J; Grant, Evan H Campbell; Kanno, Yoichiro; Chandler, Richard B; 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. PMID:24649642

  15. Base hydrolysis of HMX and HMX-based plastic-bonded explosives with sodium hydroxide between 100 and 155 C

    Microsoft Academic Search

    Robert L. Bishop; Raymond L. Flesner; Philip C. Dell'Orco; Terry Spontarelli; Sheldon A. Larson; David A. Bell

    1999-01-01

    The degradation of HMX-based high explosives (HMX, PBX 9404, and PBX 9501) with sodium hydroxide solutions is described. To obtain practicable reaction rates, the reaction was carried out in a pressurized reactor at temperatures up to about 155 C. Above about 70 C, mass transfer rates significantly affect the observed reaction rate. Therefore, a solid-liquid mass transfer model, based on

  16. A new proof of the Pythagorean using a compass and unmarked straight edge

    Microsoft Academic Search

    Medhat H. Rahim

    2003-01-01

    In this note, a new proof of the Pythagorean Theorem will be presented using only a compass and an unmarked straight edge. As a background, interesting dissection proofs of the Hindu mathematician Bhaskara and the Arabic scholar Tabit ibn-Qorra are highlighted.

  17. GPR and bulk ground resistivity surveys in graveyards: locating unmarked burials in contrasting soil types.

    PubMed

    Hansen, James D; Pringle, Jamie K; Goodwin, Jon

    2014-04-01

    With graveyards and cemeteries globally being increasingly designated as full, there is a growing need to identify unmarked burial positions to find burial space or exhume and re-inter if necessary. In some countries, for example the U.S. and U.K., burial sites are not usually re-used; however, most graveyard and cemetery records do not have maps of positions. One non-invasive detection method is near-surface geophysics, but there has been a lack of research to-date on optimal methods and/or equipment configuration. This paper presents three case studies in contrasting burial environments, soil types, burial styles and ages in the U.K. Geophysical survey results reveal unmarked burials could be effectively identified from these case studies that were not uniform or predicted using 225 MHz frequency antennae GPR 2D 0.5 m spaced profiles. Bulk ground electrical surveys, rarely used for unmarked burials, revealed 1 m probe spacings were optimal compared to 0.5 m, with datasets needing 3D detrending to reveal burial positions. Results were variable depending upon soil type; in very coarse soils GPR was optimal; whereas resistivity was optimal in clay-rich soils and both were optimal in sandy and black earth soils. Archaeological excavations revealed unmarked burials, extra/missing individuals from parish records and a variety of burial styles from isolated, brick-lined, to vertically stacked individuals. Study results, evidence unmarked burial targets were significantly different from clandestine burials of murder victims which are used as analogues. PMID:24559798

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Explosives tester

    DOEpatents

    Haas, Jeffrey S. (San Ramon, CA); Howard, Douglas E. (Livermore, CA); Eckels, Joel D. (Livermore, CA); Nunes, Peter J. (Danville, CA)

    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.

  3. Detonation wave profiles in HMX based explosives

    NASA Astrophysics Data System (ADS)

    Gustavsen, R. L.; Sheffield, S. A.; Alcon, R. R.

    1998-07-01

    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 ?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.

  4. 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.

  5. Evaluation of novel Brucella melitensis unmarked deletion mutants for safety and efficacy in the goat model of brucellosis

    Microsoft Academic Search

    Melissa M. Kahl-McDonagh; Philip H. Elzer; Sue D. Hagius; Joel V. Walker; Quinesha L. Perry; Christopher M. Seabury; Andreas B. den Hartigh; Renee M. Tsolis; L. Garry Adams; Donald S. Davis; Thomas A. Ficht

    2006-01-01

    Pregnant goats were employed to assess unmarked deletion mutant vaccine candidates BM?asp24, BM?cydBA, and BM?virB2, as the target host species naturally infected with Brucella melitensis. Goats were assessed for the degree of pathology associated with the vaccine strains as well as the protective immunity afforded by each strain against abortion and infection after challenge with wild-type Brucella melitensis 16M. Both

  6. On the low pressure shock initiation of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine based plastic bonded explosives

    Microsoft Academic Search

    Kevin S. Vandersall; Craig M. Tarver; Frank Garcia; Steven K. Chidester

    2010-01-01

    In large explosive and propellant charges, relatively low shock pressures on the order of 1-2 GPa impacting large volumes and lasting tens of microseconds can cause shock initiation of detonation. The pressure buildup process requires several centimeters of shock propagation before shock to detonation transition occurs. In this paper, experimentally measured run distances to detonation for lower input shock pressures

  7. On the low pressure shock initiation of octahydro-1,3,5,7–tetranitro-1,3,5,7-tetrazocine based plastic bonded explosives

    Microsoft Academic Search

    Kevin S. Vandersall; Craig M. Tarver; Frank Garcia; Steven K. Chidester

    2010-01-01

    In large explosive and propellant charges, relatively low shock pressures on the order of 1–2 GPa impacting large volumes and lasting tens of microseconds can cause shock initiation of detonation. The pressure buildup process requires several centimeters of shock propagation before shock to detonation transition occurs. In this paper, experimentally measured run distances to detonation for lower input shock pressures

  8. 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

  9. Unmarked insertional mutagenesis in the bovine pathogen Mycoplasma mycoides subsp. mycoides SC

    PubMed Central

    Janis, Carole; Bischof, Daniela; Gourgues, Géraldine; Frey, Joachim; Blanchard, Alain; Sirand-Pugnet, Pascal

    2009-01-01

    Mycoplasma mycoides subspecies mycoides small colony (SC) is the aetiologic agent of contagious bovine pleuropneumonia (CBPP), a respiratory disease causing important losses in cattle production. The publication of the genome sequence of M. mycoides subsp. mycoides SC should facilitate the identification of putative virulence factors. However, real progress in the study of molecular mechanisms of pathogenicity also requires efficient molecular tools for gene inactivation. In the present study, we have developed a transposon-based approach for the random mutagenesis of M. mycoides subsp. mycoides SC. A PCR-based screening assay enabled the characterization of several mutants with knockouts of genes potentially involved in pathogenicity. The initial transposon was further improved by combining it with the transposon ?? TnpR/res recombination system to allow the production of unmarked mutations. Using this approach, we isolated a mutant free of antibiotic-resistance genes, in which the gene encoding the main lipoprotein LppQ was disrupted. The mutant was found to express only residual amounts of the truncated N-terminal end of LppQ. This approach opens the way to study virulence factors and pathogen-host interactions of M. mycoides subsp. mycoides SC and to develop new, genetically defined vaccine strains. PMID:18667575

  10. Application of gas-liquid film theory to base hydrolysis of HMX powder and HMX-based plastic-bonded explosives using sodium carbonate

    SciTech Connect

    Bishop, R.L.; Flesner, R.L.; Dell`Orco, P.C.; Spontarelli, T.; Larson, S.A. [Los Alamos National Lab., NM (United States)] [Los Alamos National Lab., NM (United States); Bell, D.A. [Univ. of Wyoming, Laramie, WY (United States). Dept. of Petroleum and Chemical Engineering] [Univ. of Wyoming, Laramie, WY (United States). Dept. of Petroleum and Chemical Engineering

    1998-12-01

    Sodium carbonate (Na{sub 2}CO{sub 3}) is identified as a hydrolysis reagent for decomposing HMX and HMX-based explosives to water-soluble, nonenergetic products. The reaction kinetics of Na{sub 2}CO{sub 3} hydrolysis are examined, and a reaction rate model is developed. Greater than 99% of the explosive at an initial concentration of 10 wt % PBX 9404 was destroyed in less than 5 min at 150 C. The primary products from Na{sub 2}CO{sub 3} hydrolysis were nitrite (NO{sub 2}), formate (HCOO{sup {minus}}), nitrate (NO{sub 3}{sup {minus}}), and acetate (CH{sub 3}COO{sup {minus}}) ions, hexamethylenetetramine, (hexamine: C{sub 6}H{sub 12}N{sub 4}), nitrogen gas (N{sub 2}), nitrous oxide (N{sub 2}O), and ammonia (NH{sub 3}). The rate of hydrolysis was characterized for HMX powder and PBX 9404 molding powder from 110 to 150 C. The rate was found to be dependent on both the chemical kinetics and the mass transfer resistance. Since the HMX particles are nonporous and external mass transfer dominates, gas-liquid film theory for fast chemical kinetics was used to model the reaction rate.

  11. 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.

  12. 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.

  13. 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).

  14. Specific gene targeting in Spiroplasma citri: improved vectors and production of unmarked mutations using site-specific recombination.

    PubMed

    Duret, Sybille; André, Aurélie; Renaudin, Joël

    2005-08-01

    In Spiroplasma citri, where homologous recombination is inefficient, specific gene targeting could only be achieved by using replicative, oriC plasmids. To improve the probability of selecting rare recombination events without fastidious, extensive passaging of the transformants, a new targeting vector was constructed, which was used to inactivate the crr gene encoding the IIA component of the glucose phosphotransferase system (PTS) permease. Selection of recombinants was based on a two-step strategy using two distinct selection markers, one of which could only be expressed once recombination had occurred through one single crossover at the target gene. According to this strategy, spiroplasmal transformants were screened and multiplied in the presence of gentamicin before the crr recombinants were selected for their resistance to tetracycline. In contrast to the wild-type strain GII-3, the crr-disrupted mutant GII3-gt1 used neither glucose nor trehalose, indicating that in S. citri the glucose and trehalose PTS permeases function with a single IIA component. In addition, the feasibility of using the transposon gammadelta TnpR/res recombination system to produce unmarked mutations in S. citri was demonstrated. In an arginine deiminase (arcA-disrupted) mutant, the tetM gene flanked by the res sequences was efficiently excised from the chromosome through expression of the TnpR resolvase from a replicative oriC plasmid. Due to oriC incompatibility, plasmid loss occurred spontaneously when selection pressure was removed. This approach will be helpful for constructing unmarked mutations and generating multiple mutants with the same selection marker in S. citri. It should also be relevant to other species of mollicutes. PMID:16079355

  15. 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%.

  16. Population Explosion

    NSDL National Science Digital Library

    The Wisconsin Fast Plants Program

    A series of experiments explore the effects of increased population growth on a population of Fast Plants. Through these inquiries, students will better understand the many substantial and pertinent issues surrounding human population explosion on Earth.These experiments can be adjusted toward middle, high school or post-secondary levels.

  17. Explosive complexes

    DOEpatents

    Huynh, My Hang V. (Los Alamos, NM)

    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.

  18. 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.

  19. Soda Explosion

    NSDL National Science Digital Library

    Science Center of Connecticut

    1999-01-01

    This hands-on activity lets participant explore chemical reactions as they create a soda explosion with lots of bubbles. The bubbles in soda are made of carbon dioxide gas. Using lifesaver mint candy, create a fun, foaming mess. Experimenting in an outside space is suggested.

  20. Aktau Plastics Plant Explosives Material Report

    Microsoft Academic Search

    ROGER S

    1999-01-01

    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

  1. 49 CFR 173.60 - General packaging requirements for explosives.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...packaging or of the article, or both. (11) Plastic packagings may not be able to generate or accumulate sufficient static electricity to cause the packaged explosive substances or articles to initiate, ignite or inadvertently function. Metal...

  2. 49 CFR 173.60 - General packaging requirements for explosives.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...packaging or of the article, or both. (11) Plastic packagings may not be able to generate or accumulate sufficient static electricity to cause the packaged explosive substances or articles to initiate, ignite or inadvertently function. Metal...

  3. 49 CFR 173.60 - General packaging requirements for explosives.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...packaging or of the article, or both. (11) Plastic packagings may not be able to generate or accumulate sufficient static electricity to cause the packaged explosive substances or articles to initiate, ignite or inadvertently function. Metal...

  4. 49 CFR 173.60 - General packaging requirements for explosives.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...packaging or of the article, or both. (11) Plastic packagings may not be able to generate or accumulate sufficient static electricity to cause the packaged explosive substances or articles to initiate, ignite or inadvertently function. Metal...

  5. 49 CFR 173.60 - General packaging requirements for explosives.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...packaging or of the article, or both. (11) Plastic packagings may not be able to generate or accumulate sufficient static electricity to cause the packaged explosive substances or articles to initiate, ignite or inadvertently function. Metal...

  6. 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

  7. 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.

  8. Supernova Explosions

    NSDL National Science Digital Library

    In this activity, students are reminded that the Universe is made up of elements and that the heavier elements are created inside of a star, as they learned in the "Elements and You" activity. They are introduced to the life cycle of a star and to the way in which a star's mass affects its process of fusion and eventual death. Students discuss the physical concept of equilibrium as a balancing of forces and observe an experiment to demonstrate what happens to a soda can when the interior and exterior forces are not in equilibrium. An analogy is made between this experiment and core collapse in stars, to show the importance of maintaining equilibrium in stars. Finally, students participate in an activity which demonstrates how mass is ejected from a collapsed star in a supernova explosion, thereby dispersing heavier elements throughout the Universe. This activity is part of a series that has been designed specifically for use with Girl Scouts, but the activities can be used in other settings. Most of the materials are inexpensive or easily found. It is recommended that a leader with astronomy knowledge lead the activities, or at least be available to answer questions, whenever possible.

  9. Method for digesting a nitro-bearing explosive compound

    DOEpatents

    Shah, Manish M. (Richland, WA)

    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.

  10. Bioremediation of high explosives

    SciTech Connect

    Kitts, C.L.; Alvarez, M.A.; Hanners, J.L.; Ogden, K.L.; Vanderberg-Twary, L.; Unkefer, P.J. [Los Alamos National Lab., NM (United States). Chemical Science and Technology Div.

    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).

  11. 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

  12. Non-Shock Initiation Model for Explosive Families: Numerical Results

    NASA Astrophysics Data System (ADS)

    Todd, S. N.; Anderson, M. U.; Caipen, T. L.; Grady, D. E.

    2009-12-01

    A damage initiated reaction (DMGIR) computational model is being developed for the CTH shock physics code to predict the response of an explosive 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 reaction in the explosive, and its growth to detonation. The DMGIR model is a complement to the History Variable Reactive Burn (HVRB) model embedded in the current CTH code. Specifically designed experiments are supporting the development, implementation, and validation of the DMGIR numerical approach. PBXN-5 was the initial explosive material used experimentally to develop the DMGIR model. This explosive represents a family of plastically bonded explosives with good mechanical strength and rigid body properties. The model has been extended to cast explosives represented by Composition B.

  13. Explosives detection with energetic photons

    NASA Astrophysics Data System (ADS)

    Habiger, K. W.; Clifford, J. R.; Miller, R. B.; McCullough, W. F.

    1991-05-01

    TITAN has developed a new technique for detecting explosives using an rf linac. The patented EXDEP technique uses an intense 13.5-MeV electron-generated X-ray beam to photoactivate the nitrogen comprising > 18.5% of most explosives. Activated nitrogen (t1/2 = 10 min) decays emitting a positron, which annihilates producing two 511 keV photons that are detected. The rf linac's electron energy is selected to optimize the nitrogen activation and minimize background. In a DARPA/Sandia National Laboratory sponsored countermine program, TITAN developed a model, benchmarked it with experiments, and used it to determine the parameters for a prototype system. Experiments at the Naval Research Laboratory verified that EXDEP could detect plastic and metal buried mines in sand and soil. An EXDEP system has been designed to screen luggage for concealed explosives. An rf linac illuminates the luggage, a detector array provides a 3D image of the activity concentration within the luggage, and a 3D computer tomography X-ray scanner maps the physical density of those areas. Calculations have shown that the probability of detection will be > 99% with a false-alarm probability of < 1%.

  14. 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.

  15. Inspection tester for explosives

    DOEpatents

    Haas, Jeffrey S. (San Ramon, CA); Simpson, Randall L. (Livermore, CA); Satcher, Joe H. (Patterson, CA)

    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.

  16. Inspection tester for explosives

    SciTech Connect

    Haas, Jeffrey S. (San Ramon, CA); Simpson, Randall L. (Livermore, CA); Satcher, Joe H. (Patterson, CA)

    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.

  17. Plastic Surgery

    MedlinePLUS

    ... her forehead lightened with a laser? What Is Plastic Surgery? Just because the name includes the word " ... two such treatments. Continue Why Do Teens Get Plastic Surgery? Most teens don't, of course. But ...

  18. Conductive plastics

    Microsoft Academic Search

    Barry M. Lunt; A. Brent Strong

    2003-01-01

    Plastics have been widely used for several decades, due to their many advantageous properties including moldability, ruggedness, and low cost. For applications in electricity and electronics, applications for plastics have always been as dielectrics, due to their inherent property as electrical insulators. The invention of conductive plastics has enabled the creation of many products that have previously not existed. This

  19. 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.

  20. Mechanical Behavior of TNAZ/Hytemp Explosives during High Acceleration

    NASA Astrophysics Data System (ADS)

    Lanzerotti, Y.; Sharma, J.; Capellos, C.

    2006-07-01

    The mechanical behavior of TNAZ/Hytemp (1,3,3-trinitroazetidine/polyacrylic elastomer) explosives subjected to high acceleration has been studied in an ultracentrifuge. Pressed plastic-bonded TNAZ/Hytemp was studied as a function of the percentage of Hytemp at -10°C and 25°C. The percentage of Hytemp in the samples varied from 1% (weight percent) to 2% (weight percent). Failure occurs when the shear or tensile strength of the explosive is exceeded. The fracture acceleration of pressed plastic-bonded TNAZ/Hytemp decreases with increasing percentage of Hytemp in the explosive at -10°C and 25°C. The fracture acceleration of pressed plastic-bonded 98%/2% (weight percent) TNAZ/Hytemp at 25°C is about 1/3 that at -10°C.

  1. A simple model for explosives formulation

    SciTech Connect

    Rivera, T.

    1993-01-01

    A simple model based on surface chemistry is developed, based an simple concepts of contact angle, wetting and spreading. Results of the modeling can be stated by two simplified rules of thumb'': (1) A liquid will spread on the surface of a solid if the surface tension of the liquid is lose than the surface free energy of the solid, and (2) The liquid having the surface tension nearest that of the solid will preferentially wet the surface of the solid. These two rules can then be used to define the parameters that constitute a process for formulating a plastic bonded explosive (PBX), which is a crystalline high-explosive material coated with a small amount of plastic polymeric material (the binder). The PBX then can be pressed to a high density, and machined to a specific shape. The pressed and machined explosive material can then be used in a physics experiment to study fundamental properties of either the explosive or some other material.

  2. A simple model for explosives formulation

    SciTech Connect

    Rivera, T.

    1993-04-01

    A simple model based on surface chemistry is developed, based an simple concepts of contact angle, wetting and spreading. Results of the modeling can be stated by two simplified ``rules of thumb``: (1) A liquid will spread on the surface of a solid if the surface tension of the liquid is lose than the surface free energy of the solid, and (2) The liquid having the surface tension nearest that of the solid will preferentially wet the surface of the solid. These two rules can then be used to define the parameters that constitute a process for formulating a plastic bonded explosive (PBX), which is a crystalline high-explosive material coated with a small amount of plastic polymeric material (the binder). The PBX then can be pressed to a high density, and machined to a specific shape. The pressed and machined explosive material can then be used in a physics experiment to study fundamental properties of either the explosive or some other material.

  3. Low vulnerability explosives (LOVEX) for mass-use warheads

    SciTech Connect

    Pruneda, C.; Jessop, E.; McGuire, R.

    1990-03-13

    There is an ongoing effort at Lawrence Livermore National Laboratory to develop explosives with a significantly lower vulnerability to battlefield environments (bullets, fragments, sympathetic detonation) than current explosives (TNT and Comp B) without sacrificing performance or increasing costs. The approach taken is to develop a composite explosive which is comprised of inexpensive fillers such as RDX, NaNO{sub 3}, Al and a low modulus binder system. The binder system uses nitroglycerin/triacetin as an energetic plasticizer. This paper discusses the experimental results to date in vulnerability, performance and processing. 7 refs., 8 figs., 6 tabs.

  4. Method of digesting an explosive nitro compound

    DOEpatents

    Shah, Manish M. (Richland, WA)

    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.

  5. Free radical explosive composition

    DOEpatents

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

    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.

  6. Explosives tester with heater

    DOEpatents

    Del Eckels, Joel (Livermore, CA); Nunes, Peter J. (Danville, CA); Simpson, Randall L. (Livermore, CA); Whipple, Richard E. (Livermore, CA); Carter, J. Chance (Livermore, CA); Reynolds, John G. (San Ramon, CA)

    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.

  7. Plastic Stretch

    NSDL National Science Digital Library

    Stoebe, Thomas G.

    This learning activity will be helpful for students learning about plastic deformation. Specifically, the exercise looks at plastic deformation in polyethylene, which is found in plastic sheets, bags and other common items. Students will participate in plastic deformation of a polymer, observe "necking" in the material and its effect on strength and relate the behavior of the sample to crystallization. This activity would be suitable at any level, from elementary school to college, with each age group gaining different educational benefits. The lesson should take about 5 to 10 minutes of class time, plus time for discussion. This document will serve as a framework for instructors and may be downloaded in PDF format.

  8. 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).

  9. Plastics Technology.

    ERIC Educational Resources Information Center

    Barker, Tommy G.

    This curriculum guide is designed to assist junior high schools industrial arts teachers in planning new courses and revising existing courses in plastics technology. Addressed in the individual units of the guide are the following topics: introduction to production technology; history and development of plastics; safety; youth leadership,…

  10. Plastic bottle

    NSDL National Science Digital Library

    Jake Wasdin (None; )

    2006-07-08

    Many plastic items, like bags and especially bottles, can be recycled. Recycling the plastic rings that hold soda pop cans together is a major help for the environment. Birds sometimes get stuck in these rings and can't move or eat anymore.

  11. Plastic Packaging

    NSDL National Science Digital Library

    2008-01-01

    In this data collection and analysis activity students investigate the data in connection with recyclable materials and develop plans to help the environment. Through this activity, students explore recycling plastic containers and graph the frequency of different types of recyclable plastics. The lesson includes student worksheets, extension suggestions, and student questions.

  12. 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.

  13. The Cambrian Explosion

    NSDL National Science Digital Library

    This University of Bristol page discusses in detail the Cambrian Explosion event that occurred about 545 million years ago. This site covers what the 'explosion' was and when it happened, the Cambrian environment, what caused this event to occur, fossil groups and their significance, and controversies surrounding this theory as well as recent discoveries.

  14. Inside an Explosion

    NSDL National Science Digital Library

    KQED

    2009-10-30

    From afar, an explosion may seem like one of the most incredible examples of chaotic interaction. But once you look closer, as in this video from QUEST, you will find that large-scale explosions require very precise interactions to occur in just the right sequence.

  15. An explosion in Tunguska

    Microsoft Academic Search

    Ioan Nistor

    2008-01-01

    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

  16. Query Nuclear Explosions Database

    NSDL National Science Digital Library

    2002-01-01

    NUCEXP, National Geoscience Database, provided by the Australian Geological Survey Organization (AGSO), contains entries on nuclear explosions around the world since 1945, with the location, time and size of explosions. To view the records, users must select site and country conducting the test and beginning/end dates.

  17. 78 FR 64246 - Commerce in Explosives; List of Explosives Materials

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-28

    ...metals. Aluminum containing polymeric propellant. Aluminum ophorite explosive. Amatex...excluding ammonium perchlorate composite propellant (APCP)). Ammonium picrate [picrate...Nitroguanidine explosives. Nitronium perchlorate propellant mixtures. Nitroparaffins...

  18. Cotton Gin Dust Explosibility Determinations

    E-print Network

    Vanderlick, Francis Jerome

    2014-01-06

    Following the recent Imperial sugar dust explosion in 2008, a comprehensive survey of past dust explosions was conducted by the Occupational Safety and Health Administration (OSHA) to determine potential explosible dusts. After the survey, OSHA...

  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. 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.

  1. 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.

  2. Non-detonable explosive simulators

    DOEpatents

    Simpson, Randall L. (Livermore, CA); Pruneda, Cesar O. (Livermore, CA)

    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.

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

    NASA Astrophysics Data System (ADS)

    Maienschein, J. L.

    2014-05-01

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

  4. Plastic welder

    NASA Technical Reports Server (NTRS)

    Buckley, J. D.; Fox, R. L.; Swain, R. J.

    1980-01-01

    Low-cost, self-contained, portable welder joins plastic parts by induction heating. Welder is useable in any atmosphere or in vacuum and with most types of thermoplastic; plastic components can be joined in situ. Device is applicable to aerospace industry and in automobile, furniture, and construction industries. Power requirements are easily met by battery or solar energy. In welder, toroidal inductor transfers magnetic flux through thermoplastic to screen. Heated screen causes plastic surface on either side to melt and flow into it to form joint.

  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. Milk Plastic

    NSDL National Science Digital Library

    Mission Science Workshop

    2013-01-01

    In this activity, learners transform everyday milk into small plastic figurines and jewelry. Use this activity to introduce learners to monomers and polymers. Note: this activity requires adult supervision.

  7. Lithium niobate explosion monitor

    DOEpatents

    Bundy, Charles H. (Clearwater, FL); Graham, Robert A. (Los Lunas, NM); Kuehn, Stephen F. (Albuquerque, NM); Precit, Richard R. (Albuquerque, NM); Rogers, Michael S. (Albuquerque, NM)

    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.

  8. 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.

  9. Simulation of high explosive explosion using adaptive material point method

    Microsoft Academic Search

    Shang Ma; Xiong Zhang; Yanping Lian; Xu Zhou

    2009-01-01

    Numerical simulation of high explosive explosion problems is a big challenge to traditional numerical methods because explosion usually involves ex- tremely large deformation and multi-material interaction of different phases. Re- centlydevelopedmeshfreemethodsshowmuchadvantagesovermesh-basedmethod for problems associated with very large deformation. Some of them have been successfully applied to impact and explosion problems, such as smoothed particle hydrodynamics (SPH). Similar to SPH, material

  10. Polymer blends as high explosive binders

    SciTech Connect

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

    1984-10-05

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

  11. 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

  12. 75 FR 5545 - Explosives

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-03

    ...governing occupational exposure to respirable silica. Inhalation of this substance, which is extremely widespread, causes lung disease, silicosis and lung cancer. Terminating the explosives rulemaking will free resources for these and other...

  13. 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

  14. Explosion suppression system

    DOEpatents

    Sapko, Michael J. (Finleyville, PA); Cortese, Robert A. (Pittsburgh, PA)

    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.

  15. 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.

  16. 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.

  17. 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.

  18. Explosive Welding and Cladding

    NASA Astrophysics Data System (ADS)

    Meuken, D.; Carton, E. P.

    2004-07-01

    Explosive welding or cladding is usually performed on relative thick plates by means of a large scale parallel plate set-up. At TNO-PML several of the explosive welding configurations that were developed mainly in the nineteen sixties and seventies are being investigated for their potential use in modern industrial applications. Configurations for explosive cladding of curved surfaces such as tubes and rods are also being examined. This can be used to make special bimetallic heat exchanger tubes, or for the protection of electrodes that are used in electrolysis. Explosive line and seam welding are important bonding techniques that allow the welding of both similar and dissimilar metal plates and sheets. Here, bonding occurs over a small overlapping fraction of the two surfaces. This requires only a small amount of explosive (e.g. 5 g/m for line welds in thin ductile sheets). Explosive foil cladding can be used as an alternative coating technique. Plates that are clad with a foil on one or both sides were fabricated in one process step. They can be further machined or deformed using conventional techniques, due to the ductility of the bond and clad material.

  19. 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

  20. 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

  1. 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.

  2. Non-detonable and non-explosive explosive simulators

    DOEpatents

    Simpson, Randall L. (Livermore, CA); Pruneda, Cesar O. (Livermore, CA)

    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.

  3. Molecular models for explosives

    SciTech Connect

    Ritchie, J.P.; Bachrach, S.M.

    1987-01-01

    Any fundamental understanding of detonations and explosives' behavior requires as a starting point a knowledge of molecular properties. Indeed, there is a sizable literature concerning observed decomposition kinetics, x-ray crystal structures, heats of formation, etc. for explosives. As a result of this extensive experimental work, a large and ever increasing number of observed properties of explosives are available. Given sufficient data, models for the prediction of molecular properties can be developed and calibrated. Nevertheless, many desirable molecular properties can be obtained with considerable effort and, in many cases, experimental measurements are not possible for practical reasons; e.g., bond dissociation energies are very difficult to obtain for explosives. Consequently, theoretical methods for obtaining these properties are quite desirable. In addition, it is oftentimes desired to estimate the properties of unknown molecules. Consequently, methods for the estimation of molecular properties, which might seem quite crude by other standards, can be of considerable practical value. We present in this paper some of our recent efforts at extending and developing molecular models for explosives. These efforts fall into three main areas: Estimation of crystal densities of organic nitrates and perchlorates by an entirely empirical group additivity method; calculation of molecular heats of formation and bond dissociation energies (BDE's) by a semi-empirical molecular orbital method (AM1); and the electronic structure of nitrobenzene as obtained from non-empirical (sometimes called ab initio molecular orbital calculations. 10 refs.

  4. 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.

  5. Comparison of the Construction of Unmarked Deletion Mutations in Mycobacterium smegmatis, Mycobacterium bovis Bacillus Calmette-Guérin, and Mycobacterium tuberculosis H37Rv by Allelic Exchange

    PubMed Central

    Pavelka, Martin S.; Jacobs, William R.

    1999-01-01

    Until recently, genetic analysis of Mycobacterium tuberculosis, the causative agent of tuberculosis, was hindered by a lack of methods for gene disruptions and allelic exchange. Several groups have described different methods for disrupting genes marked with antibiotic resistance determinants in the slow-growing organisms Mycobacterium bovis bacillus Calmette-Guérin (BCG) and M. tuberculosis. In this study, we described the first report of using a mycobacterial suicidal plasmid bearing the counterselectable marker sacB for the allelic exchange of unmarked deletion mutations in the chromosomes of two substrains of M. bovis BCG and M. tuberculosis H37Rv. In addition, our comparison of the recombination frequencies in these two slow-growing species and that of the fast-growing organism Mycobacterium smegmatis suggests that the homologous recombination machinery of the three species is equally efficient. The mutants constructed here have deletions in the lysA gene, encoding meso-diaminopimelate decarboxylase, an enzyme catalyzing the last step in lysine biosynthesis. We observed striking differences in the lysine auxotrophic phenotypes of these three species of mycobacteria. The M. smegmatis mutant can grow on lysine-supplemented defined medium or complex rich medium, while the BCG mutants grow only on lysine-supplemented defined medium and are unable to form colonies on complex rich medium. The M. tuberculosis lysine auxotroph requires 25-fold more lysine on defined medium than do the other mutants and is dependent upon the detergent Tween 80. The mutants described in this work are potential vaccine candidates and can also be used for studies of cell wall biosynthesis and amino acid metabolism. PMID:10438745

  6. Pyramiding unmarked deletions in Ralstonia solanacearum shows that secreted proteins in addition to plant cell-wall-degrading enzymes contribute to virulence.

    PubMed

    Liu, Huanli; Zhang, Shuping; Schell, Mark A; Denny, Timothy P

    2005-12-01

    Ralstonia solanacearum, like many phytopathogenic bacteria, makes multiple extracellular plant cell-wall-degrading enzymes (CWDE), some of which contribute to its ability to cause wilt disease. CWDE and many other proteins are secreted to the milieu via the highly conserved type II protein secretion system (T2SS). R. solanacearum with a defective T2SS is weakly virulent, but it is not known whether this is due to absence of all the CWDE or the loss of other secreted proteins that contribute to disease. These alternatives were investigated by creating mutants of wild-type strain GMI1000 lacking either the T2SS or up to six CWDE and comparing them for virulence on tomato plants. To create unmarked deletions, genomic regions flanking the target gene were polymerase chain reaction (PCR)-amplified, were fused using splice overlap extension PCR, were cloned into a suicide plasmid harboring the sacB counter-selectable marker, and then, were site-specifically introduced into the genome. Various combinations of five deletions (delta pehA, delta pehB, delta B, PehC, and Pme) was not statistically different from GMI1000, but all the mutants lacking one or both cellulolytic enzymes (Egl or CbhA) wilted plants significantly more slowly than did the wild type. The GMI-6 mutant that lacks all six CWDE was more virulent than the mutant lacking only its two cellulolytic enzymes, and both were significantly more virulent than the T2SS mutant (GMI-D). Very similar results were observed in wounded-petiole inoculation assays, so GMI-6 and GMI-D appear to be less capable of colonizing tomato tissues after invasion. Because the T2SS mutant was much less virulent than the sixfold CWDE mutant, we conclude that other secreted proteins contribute substantially to the ability of R. solanacearum GMI1000 to systemically colonize tomato plants. PMID:16478049

  7. 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.

  8. Epigenetics and Developmental Plasticity

    E-print Network

    Champagne, Frances A.

    Epigenetics and Developmental Plasticity Across Species ABSTRACT: Plasticity is a typical feature in developmental plasticity. Thus, in the context of the concept of developmental homology, epigenetic mechanisms methylation; developmental plasticity; homology; inheritance; phenotypic diversity INTRODUCTION Development

  9. High-nitrogen explosives

    SciTech Connect

    Naud, D. (Darren); Hiskey, M. A. (Michael A.); Kramer, J. F. (John F.); Bishop, R. L. (Robert L.); Harry, H. H. (Herbert H.); Son, S. F. (Steven F.); Sullivan, G. K. (Gregg 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).

  10. 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.

  11. Convection in Supernova Explosions

    NASA Astrophysics Data System (ADS)

    Benz, W.; Herant, M.; Colgate, S. A.

    1992-12-01

    We present the results of 2D numerical simulations of the early phase (t <= 1s) of a supernova explosion. The explosion is powered by neutrino absorption on free nucleons and neutrino scattering by electrons. We also include energy losses through neutrino emission following electron or positron capture by protons and neutrons as well as plasma neutrino emission processes. We show that neutrino heating results in a strongly convective region close to the neutron star. Hot material quickly rises whereas cold material is sinking towards the proto-neutron star. By removing the hot material from the vicinity of the neutron star, this large scale convection prevents overheating and hence limits energy losses through neutrino emission. In addition, the rising bubbles drive a strong shock outwards which eventually will lead to a successful explosion. The convective pattern is found to choose the largest mode possible in the computational domain. It follows that convective motions do not average out resulting in a net asymmetry of the explosion. If this asymmetry is confirmed by three-dimensional simulations, it could easily explain the observed high velocity dispersion of pulsars.

  12. Portable raman explosives detection

    SciTech Connect

    Moore, David Steven [Los Alamos National Laboratory; Scharff, Robert J [Los Alamos National Laboratory

    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.

  13. The combustion of explosives

    SciTech Connect

    Son, S. F. (Steven 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.

  14. 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.

  15. Overview of dust explosibility characteristics

    Microsoft Academic Search

    Kenneth L. Cashdollar

    2000-01-01

    This paper is an overview of and introduction to the subject of dust explosions. The purpose is to provide information on the explosibility and ignitability properties of dust clouds that can be used to improve safety in industries that generate, process, use, or transport combustible dusts. The requirements for a dust explosion are: a combustible dust, dispersed in air, a

  16. Big Explosives Experimental Facility - BEEF

    SciTech Connect

    None

    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.

  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. Chemical destruction of HMX-based explosives with ammonium hydroxide

    SciTech Connect

    Skidmore, C.; Dell`Orco, P.; Flesner, R.; Kramer, J.; Spontarelli, T.

    1995-09-01

    A series of experiments at Los Alamos National Laboratory explored the efficacy of ammonium hydroxide solutions in converting HMX (cyclotetramethylene-tetranitramine, or Octogen) and HMX-based explosives to nonenergetic, nonhazardous materials. When 80 g of explosive was converted in a reactor operating at 85 psig pressure at 140 C, the principal gaseous products were nitrous oxide (46% to 51%), nitrogen (22% to 32%), and ammonia (17% to 28%). Formate and hexamethylene-tetramine (hexamine) account for effectively 100% of the carbon-bearing aqueous species. Nitrate, nitrite, and acetate were present in the liquid in trace amounts. The process effectively treated molding powders of the plastic-bonded explosives PBX 9501 (2.5% estane), LX-04 (15% viton), and PBX 9404 (3% nitrocellulose). Results were compared with those achieved using sodium hydroxide solutions at 150 C in a pressurized reactor.

  19. Mechanical modeling of the plastic bonded explosive LX17

    E-print Network

    Clayton, Kyle Martin

    2001-01-01

    V (46) 2 Rearranging gives: f C?'?, '~za~pdV=f pfd"AvdV+f T, ""AvdS ? f o", ., ApddV ? f Aa?". Ap?dV (47) G 2 which can be expressed in matrix notation as follows: f ([D][hv] )[C'][D][du]dV= f [Av] pr f""]dV+ f [trav] [T""]dS ? f ([D][Av]')[o "]d...

  20. A Suitable Streptomycin-Resistant Mutant for Constructing Unmarked In-Frame Gene Deletions Using rpsL as a Counter-Selection Marker

    PubMed Central

    Tsai, Yu-Kuo; Liou, Ci-Hong; Lin, Jung-Chung; Ma, Ling; Fung, Chang-Phone; Chang, Feng-Yee; Siu, L. Kristopher

    2014-01-01

    The streptomycin counter-selection system is a useful tool for constructing unmarked in-frame gene deletions, which is a fundamental approach to study bacteria and their pathogenicity at the molecular level. A prerequisite for this system is acquiring a streptomycin-resistant strain due to rpsL mutations, which encodes the ribosomal protein S12. However, in this study no streptomycin resistance was found to be caused by rpsL mutations in all 127 clinical strains of Klebsiella pneumoniae isolated from liver abscess patients. By screening 107 spontaneous mutants of streptomycin resistance from a clinical strain of K. pneumoniae, nucleotide substitution or insertion located within the rpsL was detected in each of these strains. Thirteen different mutants with varied S12 proteins were obtained, including nine streptomycin-dependent mutants. The virulence of all four streptomycin-resistant mutants was further evaluated. Compared with the parental strain, the K42N, K42T and K87R mutants showed a reduction in growth rate, and the K42N and K42T mutants became susceptible to normal human serum. In the mice LD50 (the bacterial dose that caused 50% death) assay, the K42N and K42T mutants were ?1,000-fold less lethal (?2×105 CFU) and the K87R mutant was ?50-fold less lethal (?1×104 CFU) than the parental strain (?2×102 CFU). A K42R mutant showed non-observable effects on the above assays, while this mutant exhibited a small cost (P<0.01) in an in vitro growth competition experiment. In summary, most of the K. pneumoniae strains with streptomycin resistance caused by rpsL mutations are less virulent than their parental strain in the absence of streptomycin. The K42R mutant showed similar pathogenicity to its parental strain and should be one of the best choices when using rpsL as a counter-selection marker. PMID:25268958

  1. 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

  2. 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.

  3. 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

  4. Dust cluster explosion

    SciTech Connect

    Saxena, Vikrant [School of Mathematics and Physics, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom); Institute for Plasma Research, Bhat, Gandhinagar (India); Avinash, K. [Department of Physics and Astrophysics, University of Delhi, New Delhi (India); Sen, A. [Institute for Plasma Research, Bhat, Gandhinagar (India)

    2012-09-15

    A model for the dust cluster explosion where micron/sub-micron sized particles are accelerated at the expense of plasma thermal energy, in the afterglow phase of a complex plasma discharge is proposed. The model is tested by molecular dynamics simulations of dust particles in a confining potential. The nature of the explosion (caused by switching off the discharge) and the concomitant dust acceleration is found to depend critically on the pressure of the background neutral gas. At low gas pressure, the explosion is due to unshielded Coulomb repulsion between dust particles and yields maximum acceleration, while in the high pressure regime it is due to shielded Yukawa repulsion and yields much feebler acceleration. These results are in agreement with experimental findings. Our simulations also confirm a recently proposed electrostatic (ES) isothermal scaling relation, P{sub E}{proportional_to}V{sub d}{sup -2} (where P{sub E} is the ES pressure of the dust particles and V{sub d} is the confining volume).

  5. 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.

  6. 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.

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

    DOEpatents

    Schultz, Frederick J. (Oak Ridge, TN); Caldwell, John T. (Los Alamos, NM)

    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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Zirconium hydride containing explosive composition

    DOEpatents

    Walker, Franklin E. (18 Shadow Oak Rd., Danville, CA 94526); Wasley, Richard J. (4290 Colgate Way, Livermore, CA 94550)

    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.

  13. Spectral analysis on explosive percolation

    NASA Astrophysics Data System (ADS)

    Chung, N. N.; Chew, L. Y.; Lai, C. H.

    2013-03-01

    We study the spectral properties of the process of explosive percolation. In particular, we explore how the maximum eigenvalue of the adjacency matrix of a network which governs the spreading efficiency evolves as the density of connection increases. Interestingly, for networks with connectivity that grow in an explosive way, information spreading and mass transport are found to be carried out inefficiently. In the conventional explosive percolation models that we studied, the sudden emergences of large-scale connectivity are found to come with relatively lowered efficiency of spreading. Nevertheless, the spreading efficiency of the explosive model can be increased by introducing heterogeneous structures into the networks.

  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 ?m and 4.53 ?m) 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. Low voltage nonprimary explosive detonator

    DOEpatents

    Dinegar, Robert H. (Los Alamos, NM); Kirkham, John (Newbury, GB2)

    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.

  16. Laser machining of explosives

    DOEpatents

    Perry, Michael D. (Livermore, CA); Stuart, Brent C. (Fremont, CA); Banks, Paul S. (Livermore, CA); Myers, Booth R. (Livermore, CA); Sefcik, Joseph A. (Tracy, CA)

    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.

  17. 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

  18. Adhesive properties of some fluoropolymer binders with the insensitive explosive 1,3,5-triamino-2,4,6-trinitrobenzene (TATB)

    Microsoft Academic Search

    J. D. Yeager; A. M. Dattelbaum; E. B. Orler; D. F. Bahr; D. M. Dattelbaum

    2010-01-01

    Adhesion between binders and explosive crystals is of critical importance for the mechanical performance of plastic-bonded explosives (PBXs). The surface properties of several prospective binders have been determined from static advancing contact angle measurements. The surface energies have been used to calculate theoretical work of adhesion to 1,3,5-triamino-2,4,6-trinitrobenzene (TATB), a common insensitive high explosive. The fluorinated terpolymer Oxy-461™, and Kel-F™

  19. Applying NASA's explosive seam welding

    Microsoft Academic Search

    Laurence J. Bement

    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

  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

  1. 77 FR 55108 - Explosive Siting Requirements

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-07

    ...facilities at a launch site where solid propellants, energetic liquids, or other explosives...basis of the type and quantity of solid propellants, energetic liquids, and other explosives...division 1.1 explosives and liquid propellants with trinitrotoluene (TNT)...

  2. Watersheds and Explosive percolation

    NASA Astrophysics Data System (ADS)

    Herrmann, Hans J.; Araujo, Nuno A. M.

    The recent work by Achlioptas, D'Souza, and Spencer opened up the possibility of obtaining a discontinuous (explosive) percolation transition by changing the stochastic rule of bond occupation. Despite the active research on this subject, several questions still remain open about the leading mechanism and the properties of the system. We review the largest cluster and the Gaussian models recently introduced. We show that, to obtain a discontinuous transition it is solely necessary to control the size of the largest cluster, suppressing the growth of a cluster di_ering significantly, in size, from the average one. As expected for a discontinuous transition, a Gaussian cluster-size distribution and compact clusters are obtained. The surface of the clusters is fractal, with the same fractal dimension of the watershed line.

  3. Classical nova explosions

    E-print Network

    Margarita Hernanz

    2004-12-14

    A review of the present status of nova modeling is made, with a special emphasis on some specific aspects. What are the main nucleosynthetic products of the explosion and how do they depend on the white dwarf properties (e.g. mass, chemical composition: CO or ONe)? What's the imprint of nova nucleosynthesis on meteoritic presolar grains? How can gamma rays, if observed with present or future instruments onboard satellites, constrain nova models through their nucleosynthesis? What have we learned about the turnoff of classical novae from observation with past and present X-ray observatories? And last but not least, what are the most critical issues concerning nova modeling (e.g. ejected masses, mixing mechanism between core and envelope)?

  4. 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.

  5. 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.

  6. Modeling High Explosives with the Method of Cells and Mori-Tanaka Effective Medium Theories

    Microsoft Academic Search

    B. E. Clements; E. M. Mas

    2001-01-01

    The Method of Cells (MOC) has been applied to composites consisting of large grains embedded in a small grain-binder mixture (often found in plastic bonded explosive materials). To treat the bimodal size distribution of grains we assign one of the eight MOC cells to model the effects of large grains and the other seven to the model the small grain-binder

  7. Aspects of dynamic recrystallization in shaped charge and explosively formed projectile devices

    Microsoft Academic Search

    C. Feng; L. E. Murr; C.-S. Niou

    1996-01-01

    Under a shock wave, a shaped charge (SC) liner or an explosively formed projectile (EFP) device transforms into a jet and a slug. At various laboratories, it was found that the transformation was closely related to extensive plastic flow occurring at high strain rates. Along with the shape trans-formation, there is evidence of changes in hardness, strength, grain configuration, microstructure,

  8. Non-Solid Explosives for Shaped Charges I: Explosive Parameters Measurements for Sensitized Liquid Explosives

    Microsoft Academic Search

    M. Cartwright; D. Lloyd-Roach; P. J. Simpson

    2007-01-01

    The disposal of time-expired and unexploded ordnance is a major problem for the NATO countries. Simple functioning of the device, either in its design mode or by attachment of additional explosive and firing, requires extended safety zones. Inducing deflagration could reduce co-lateral damage within the safety zone. One solution to the problem, with current explosive fillings, of producing predictable performance

  9. 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.

  10. Shock desensitizing of solid explosive

    SciTech Connect

    Davis, William C [Los Alamos National Laboratory

    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.

  11. Detection of explosives in soils

    DOEpatents

    Chambers, William B. (Edgewood, NM); Rodacy, Philip J. (Albuquerque, NM); Phelan, James M. (Bosque Farms, NM); Woodfin, Ronald L. (Sandia Park, NM)

    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.

  12. Optimal dynamic detection of explosives

    NASA Astrophysics Data System (ADS)

    Moore, D. S.; Rabitz, Herschel; McGrane, S. D.; Greenfield, M. T.; Scharff, R. J.; Chalmers, R. E.; Roslund, J.

    2011-05-01

    We are utilizing control of molecular processes at the quantum level via the best capabilities of recent laser technology and recent discoveries in optimal shaping of laser pulses to significantly enhance the standoff detection of explosives. Optimal dynamic detection of explosives (ODD-Ex) is a methodology whereby laser pulses are optimally shaped to simultaneously enhance the sensitivity and selectivity of any of a wide variety of spectroscopic methods for explosives signatures while reducing the influence of noise and environmental perturbations. We discuss here recent results using complementary ODD-Ex methods.

  13. 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.

  14. 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.

  15. Paste extrudable explosives: Their history and their current status

    SciTech Connect

    von Holtz, E.; Scribner, K.; Whipple, R.; Carley, J.

    1990-03-13

    Lawrence Livermore National Laboratory (LLNL) has a continuing effort in the development of Paste Extrudable Explosives (PEX) for use in high performance munitions. Upon request, the paste could be injected into place just prior to warhead launch, giving enhanced safety during transport, storage, and deployment. The desire for high energy (greater than Comp B) required the development of an energetic plasticizer which would not freeze in the range of {minus}54 to +74C, and yet be compatible with the desired crystalline explosive. These materials are highly viscous and extremely pseudoplastic in nature. Extensive rheological testing has been done, using a capillary rheometer, and the behavior has been fit to power law (Ostwald-deWaele) and Buckingham-Reiner models. This report will also cover the safety testing conducted on these materials, as well as the processing techniques required for their manufacture. 9 refs., 6 figs., 5 tabs.

  16. Base hydrolysis and hydrothermal processing of PBX-9404 explosive

    SciTech Connect

    Sanchez, J.A.; Flesner, R.L.; Spontarelli, T.; Dell`Orco, P.C.; Kramer, J.F.

    1994-12-31

    Base hydrolysis in combination with hydrothermal processing has been proposed as an environmentally acceptable alternative to open burning/open detonation for degradation and destruction of high explosives. In this report, we examine gaseous and aqueous products of base hydrolysis of the HMX-based plastic bonded explosive, PBX-9404. We also examine products from the subsequent hydrothermal treatment of the base hydrolysate. The gases produced from hydrolysis of PBX-9404 are ammonia, nitrous oxide, and nitrogen. Major aqueous products are sodium formate, acetate, nitrate, and nitrite, but not all carbon products have been identified. Hydrothermal processing of base hydrolysate destroyed up to 98% of the organic carbon in solution, and higher destruction efficiencies are possible. Major gas products detected from hydrothermal processing were nitrogen and nitrous oxide.

  17. Explosive actuated valve

    DOEpatents

    Byrne, Kenneth G. (Livermore, CA)

    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.

  18. Physically based simulation of explosions

    E-print Network

    Roach, Matthew Douglas

    2005-08-29

    in the movie Final Fantasy [Columbia Pictures 2001], by Square, and the asteroid detonation in Star Wars: Episode II [Twentieth Century Fox 2002]. The primary goal of my thesis is to implement a physically based explosion simulator into an existing...

  19. Detonation probabilities of high explosives

    SciTech Connect

    Eisenhawer, S.W.; Bott, T.F.; Bement, T.R.

    1995-07-01

    The probability of a high explosive violent reaction (HEVR) following various events is an extremely important aspect of estimating accident-sequence frequency for nuclear weapons dismantlement. In this paper, we describe the development of response curves for insults to PBX 9404, a conventional high-performance explosive used in US weapons. The insults during dismantlement include drops of high explosive (HE), strikes of tools and components on HE, and abrasion of the explosive. In the case of drops, we combine available test data on HEVRs and the results of flooring certification tests to estimate the HEVR probability. For other insults, it was necessary to use expert opinion. We describe the expert solicitation process and the methods used to consolidate the responses. The HEVR probabilities obtained from both approaches are compared.

  20. Gas Explosion Characterization, Wave Propagation

    E-print Network

    mixtures of methane, oxygen and nitrogen, contained within spherical balloons with controlled initial; EXPLOSIONS; HOMOGENEOUS MIXTURES; METHANE; NITROGEN; OXYGEN; PRESSURE MEASUREMENT; REFLECTION; SIMULATION for this is that larger and larger quantities of dangerous materials are produced, transported and consumed

  1. 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.

  2. Metaplasticity: the plasticity of synaptic plasticity

    Microsoft Academic Search

    Wickliffe C. Abraham; Mark F. Bear

    1996-01-01

    In thi paper, we review experimental evidence for a novel form of persistent synaptic plasticity we call metaplasticity. Metaplasticity is induced by synaptic or cellular activity, but it is not necessarilly expressed as a change in the efficacy of normal synaptic transmission. Instead, it is manifest as a change in the ability to induce subsequent synaptic plasticity such as long-term

  3. 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.

  4. Explosivity Conditions of Aqueous Solutions

    Microsoft Academic Search

    R. Thiéry; L. Mercury

    2009-01-01

    This paper focuses on the conditions for explosive boiling and gas exsolution of aqueous solutions from a thermodynamic point\\u000a of view. Indeed, the kinetic nature of these processes, hence their explosivity, can be assessed by considering their relation\\u000a with the spinodal curve of these liquids. First, the concepts of mechanical and diffusion spinodals are briefly described,\\u000a which allows us to

  5. Chemical Explosives and Rocket Propellants

    Microsoft Academic Search

    Walter B. Sudweeks; Felix F. Chen; Michael D. McPherson

    \\u000a The average citizen in today’s world gives little thought to the important role that commercial explosives play in our lives\\u000a and how their use is linked to our standard of living and our way of life. Explosives provide the energy required to give\\u000a us access to the vast resources of the earth for the advancement of civilization.

  6. Ear Plastic Surgery

    MedlinePLUS

    Ear Plastic Surgery Ear Plastic Surgery Patient Health Information News media interested in covering the latest from ... they may improve appearance and self-confidence. Can Ear Deformities Be Corrected? Formation of the ear during ...

  7. Facial Plastic Surgery Today

    MedlinePLUS

    ... Shopping Cart Trust Your Face To A Facial Plastic Surgeon.® Home Meetings & Courses Find a Surgeon Physicians’ ... FAQ's For Patients Procedures What is a Facial Plastic Surgeon Facelift Surgery Wrinkle Treatment Nose Surgery Eyelid ...

  8. Periodontal Plastic Surgery

    MedlinePLUS

    Periodontal plastic surgery is designed to restore form and function to the gum tissue, periodontal ligament, and the bone ... with conservative behavioral changes and extending to periodontal plastic surgery. Treating Periodontal Disease Periodontal disease does not ...

  9. Find a Plastic Surgeon

    MedlinePLUS

    ... Corporate Opportunities The PSF About Us Find a Plastic Surgeon Please provide search terms. ZIP or City, ... Procedure Do Your Homework Find a board-certified plastic surgeon you can trust The ASPS find a ...

  10. 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.

  11. 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

  12. Plastic Anisotropy: Relaxed Constraints,

    E-print Network

    Rollett, Anthony D.

    Objective Properties Vectorz. Taylor- factor Sngl.-slip RC model 1 Plastic Anisotropy Objective · The objective of this lecture is to complete the description of plastic anisotropy analysis of plastic deformation and texture development.! · Reid: Deformation Geometry for Materials

  13. 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.

  14. Sea of Plastic

    NSDL National Science Digital Library

    2012-05-21

    Where do our used plastic cups, packaging and other plastic products go? In this audio report from QUEST produced by KQED, learn why some cities and counties are so concerned that they've passed ordinances to try to limit plastic consumption.

  15. STATIC ELECTRICITY Plastic combs

    E-print Network

    Benitez-Nelson, Claudia

    STATIC ELECTRICITY Materials · Plastic combs · Balloons · Thread · Scissors · Cheerios · Paper plates · Plastic lids · Unflavored gelatin powder · Long hair, fleece jacket, wool sweater..... Questions of Cheerios on a paper plate. 2. Take the plastic lid and rub it against whatever is available (hair, fleece

  16. 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…

  17. Interplay of explosive thermal reaction dynamics and structural confinement

    NASA Astrophysics Data System (ADS)

    Perry, W. Lee; Zucker, Jonathan; Dickson, Peter M.; Parker, Gary R.; Asay, Blaine W.

    2007-04-01

    Explosives play a significant role in human affairs; however, their behavior in circumstances other than intentional detonation is poorly understood. Accidents may have catastrophic consequences, especially if additional hazardous materials are involved. Abnormal ignition stimuli, such as impact, spark, friction, and heat may lead to a very violent outcome, potentially including detonation. An important factor influencing the behavior subsequent to abnormal ignition is the strength and inertia of the vessel confining the explosive, i.e., the near-field structural/mechanical environment, also known as confinement (inertial or mechanical). However, a comprehensive and quantified understanding of how confinement affects reaction violence does not yet exist. In the research discussed here, we have investigated a wide range of confinement conditions and related the explosive response to the fundamentals of the combustion process in the explosive. In our experiments, a charge of an octahydrotetranitrotetrazine-based plastic bonded explosive (PBX 9501) was loaded into a gun assembly having variable confinement conditions and subjected to a heating profile. The exploding charge breached the confinement and accelerated a projectile down the gun barrel. High bandwidth pressure and volume measurements were made and a first-law analysis was used to obtain enthalpy and power from the raw data. These results were then used to quantify reaction violence. Enthalpy change and power ranged from 0-1.8 kJ and 0-12 MW for 300 mg charges, respectively. Below a confinement strength of 20 MPa, violence was found to decline precipitously with decreasing confinement, while the violence for the heaviest confinement experiments was found to be relatively constant. Both pressure and pressurization rate were found to have critical values to induce and sustain violent reaction.

  18. 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

  19. Breccias related to explosive volcanism

    NASA Astrophysics Data System (ADS)

    Wolfe, John A.

    Explosive breccia pipes were formed in the phreatomagmatic eruption of Taal volcano 60 km south of Manila, Philippines in September 1976. They were photographed in eruption which consisted of a series of small explosions occurring during the peak of activity at 10 sec intervals. These four breccia pipes formed on the collapse fault marking the margin of the much more intense eruption of 28 September 1965 when a diatreme 800 m in diameter formed. Renewed eruption in October 1977 on one of the breccia pipes blasted out the sealed plug and breccia fragments in all stages of alteration were included in the tephra. They ranged from barely agglomerated to strongly cemented through argillized and pyritized to totally replaced by silica and pyrite, fragments indistinguishable from those found in many mining districts. The violence of the explosion initiating a phreatomagmatic eruptive sequence results in strong crackling of the walls of the pipe and the crakle zone may become mineralized (cf. Braden, Chile). Usually the crater collapses on ring faults after eruption, forming a marginal tectonic breccia which can be mineralized (cf. Balatoc, Philippines.) The small craters with steep inner walls and tapering outer slopes which form during phreatomagmatic eruptions, sometimes containing lakes, are called maars and they are the surficial expression of an explosive breccia pipe or diatreme. Superficially similar craters are formed over kimberlite pipes. Hydrothermal explosion craters are somewhat similar. Collapse breccia pipes can form in the same sequence with explosive pipes. When one rising plug encounters ground water and explodes, fluostatic pressure on any other cupolas rising from the same magma drops rapidly, resulting in withdrawal of magma and collapse of walls and roof (Perry 1961). "Fluidization" is not thought to be of any significance in formation of breccia pipes (Wolfe 1980) contrary to Reynolds (1954) and many authors who have cited that work. An explosive breccia pipe is like an open window resulting in rapid depression of the isotherms of a pluton. A concentrated brine front can build up in minutes after an explosion. The very rapid cooling may explain why many explosive breccia pipes are altered by silica and pyrite only, the system being cooled before metallic solutions have time to replace breccia matrix or fragments.

  20. 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.

  1. Detection of Volatile Vapors Emitted from Explosives with a Hand-held Ion Mobility Spectrometer

    SciTech Connect

    Ewing, Robert Gordon; Miller, Carla Jean

    2001-11-01

    Vapor detection of plastic explosives is difficult because of the low vapor pressures of explosive components (i.e. RDX and PETN) present in the complex elastomeric matrix. To facilitate vapor detection of plastic explosives, detection agents (taggants) with higher vapor pressures can be added to bulk explosives during manufacture. This paper investigates the detection of two of these taggants, ethyleneglycol dinitrate (EGDN) and 2,3-dimethyl-2,3-dinitrobutane (DMNB), using a handheld ion mobility spectrometer. These two taggants were detected both from neat vapor sources as well as from bulk explosives (nitroglycerin (NG)-dynamite and C-4 tagged with DMNB). EGDN was detected from NG-dynamite as EGDN·NO3- at a reduced mobility value of 1.45 cm2 V-1 s-1 with detection limits estimated to be about 10 ppbv. DMNB was identified from tagged C-4 as both negative and positive ions with reduced mobility values of 1.33 cm2 V-1 s-1 for DMNB·NO2- and 1.44 cm2 V-1s-1 for DMNB·NH4+. Positive ions for cyclohexanone were also apparent in the spectra from tagged C-4 producing three additional peaks.

  2. 76 FR 64974 - Commerce in Explosives; List of Explosive Materials (2011R-18T)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-19

    ...metals. Aluminum containing polymeric propellant. Aluminum ophorite explosive. Amatex...excluding ammonium perchlorate composite propellant (APCP)). Ammonium picrate [picrate...Nitroguanidine explosives. Nitronium perchlorate propellant mixtures. Nitroparaffins...

  3. 75 FR 70291 - Commerce in Explosives; List of Explosive Materials (2010R-27T)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-17

    ...metals. Aluminum containing polymeric propellant. Aluminum ophorite explosive. Amatex...excluding ammonium perchlorate composite propellant (APCP)). Ammonium picrate [picrate...Nitroguanidine explosives. Nitronium perchlorate propellant mixtures. Nitroparaffins...

  4. 77 FR 58410 - Commerce in Explosives; List of Explosive Materials (2012R-10T)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-20

    ...metals. Aluminum containing polymeric propellant. Aluminum ophorite explosive. Amatex...excluding ammonium perchlorate composite propellant (APCP)). Ammonium picrate [picrate...Nitroguanidine explosives. Nitronium perchlorate propellant mixtures. Nitroparaffins...

  5. Optimal dynamic detection of explosives

    SciTech Connect

    Moore, David Steven [Los Alamos National Laboratory; Mcgrane, Shawn D [Los Alamos National Laboratory; Greenfield, Margo T [Los Alamos National Laboratory; Scharff, R J [Los Alamos National Laboratory; Rabitz, Herschel A [PRINCETON UNIV; Roslund, J [PRINCETON UNIV

    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.

  6. Optimal dynamic detection of explosives

    NASA Astrophysics Data System (ADS)

    Moore, D. S.; Rabitz, Herschel; McGrane, S. D.; Greenfield, M.; Scharff, R. J.; Beltrani, V.; Roslund, J.

    2009-05-01

    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.

  7. Preventing melt-water explosions

    NASA Astrophysics Data System (ADS)

    Taleyarkhan, R. P.

    1998-02-01

    Explosive interactions between molten aluminum and water are being studied at the Oak Ridge National Laboratory to determine the causes of explosion triggers and the extent of protection provided from various coatings in order to develop a fundamental, cost-effective methodology for prevention. The study includes experimentation and mathematical modeling of the interactions between molten metals and water on various coated and uncoated surfaces. Phenomenological issues related to surface wettability, gas generation from coatings, charring of coatings, inertial constraint, melt temperature, water temperature, and external shocks are being investigated systematically to gage their relative impact on the triggerability of surface-assisted steam explosions. A physics-based novel prevention methodology based on enhancing system stability via air (gas) injection at vulnerable locations has been developed and tested at Oak Ridge National Laboratory.

  8. Saccharification of explosively dried corn

    SciTech Connect

    Robertson, G.H.; Zaragosa, E.M.; Pavlath, A.E.

    1986-08-01

    Very rapid or explosive drying of grains such as corn leads to obvious physical changes in the macrostructure of the grain kernel, probable alteration in starch molecular structure, and reduction in starch average molecular weight. These changes lead to greater susceptibility to attack by liquefying and saccharifying enzymes. Rates of formation of nonreducing and reducing sugars by liquefying and saccharifying enzymes applied to explosively dried and milled yellow dent corn and small-kernel flint corn were 3.3-10.6 times greater then rates for the normally milled grains. The enzymatic conversion of explosively dried flint corn containing absorbed ethyl alcohol, as would be the case if it had been used as an adsorbent to dewater aqueous ethyl alcohol, was not significantly different from that of ethyl-alcohol-free flint corn. 15 references.

  9. 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.

  10. 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?

  11. 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.

  12. Nonequilibrium detonation of composite explosives

    SciTech Connect

    Nichols III, A.L.

    1997-07-01

    The effect of nonequilibrium diffusional flow on detonation velocities in composite explosives is examined. Detonation conditions are derived for complete equilibrium, temperature and pressure equilibrium, and two forms of pressure equilibrium. Partial equilibria are associated with systems which have not had sufficient time for transport to smooth out the gradients between spatially separate regions. The nonequilibrium detonation conditions are implemented in the CHEQ equation of state code. We show that the detonation velocity decreases as the non-chemical degrees of freedom of the explosive are allowed to equilibrate. It is only when the chemical degrees of freedom are allowed to equilibrate that the detonation velocity increases.

  13. Coulomb Explosion and Thermal Spikes

    NASA Astrophysics Data System (ADS)

    Bringa, E. M.; Johnson, R. E.

    2002-04-01

    A fast ion can electronically excite a solid producing a track of damage, a process initially used to detect energetic particles but now used to alter materials. From the seminal paper by Fleischer et al. [Phys. Rev. 156, 353 (1967)] to the present, ``Coulomb explosion'' and thermal spike models have been often treated as competing models for describing ion track effects. Here molecular dynamics simulations of electronic sputtering, a surface manifestation of track formation, show that in the absence of significant quenching Coulomb explosion in fact produces a spike at high excitation density, but the standard spike models are incorrect.

  14. 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

  15. Crackling noise in plasticity

    NASA Astrophysics Data System (ADS)

    Alava, Mikko J.; Laurson, Lasse; Zapperi, Stefano

    2014-10-01

    Plastic deformation is a paradigmatic problem of multiscale materials modelling with relevant processes ranging from the atomistic scale up to macroscopic scales where deformation is treated by continuum mechanics. Recent experiments, investigating deformation fluctuations under conditions where plastic deformation was expected to occur in a smooth and stable manner, demonstrate that deformation is spatially heterogeneous and temporally intermittent, not only on atomic scales, where spatial heterogeneity is expected, but also on mesoscopic scales where plastic fluctuations involve collective events of widely different amplitudes. Evidence for crackling noise in plastic deformation comes from acoustic emission measurements and from deformation of micron-scale samples both in crystalline and amorphous materials. Here we provide a detailed account of our current understanding of crackling noise in crystal and amorphous plasticity stemming from experiments, computational models and scaling theories. We focus our attention on the scaling properties of plastic strain bursts and their interpretation in terms of non-equilibrium critical phenomena.

  16. 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

  17. 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.

  18. Cosmetic Plastic Surgery Statistics

    MedlinePLUS

    ... of Medical Specialties-recognized boards. © ASPS, 2013 2012 Cosmetic Plastic Surgery Statistics Cosmetic Procedure Trends COSMETIC SURGICAL PROCEDURES201220112000 % CHANGE 2012 vs. 2011 % CHANGE 2012 ...

  19. 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

  20. Plastic Race Car Competition

    NSDL National Science Digital Library

    This video, presented by WGBH, looks at a high school outreach program to get students interested in plastic manufacturing by having them make plastic race cars. The students go through the entire process of design from both technical and hands-on perspectives. This video also serves as an overview of the different types of plastic manufacturing processes that are utilized in the industry. This video would be great for anyone interested in plastic manufacturing, or just looking to learn a little bit more about it. Educators will also find a background essay, discussion questions, and standards alignment for the material. Running time for the video is 4:32.

  1. Lead-free primary explosives

    DOEpatents

    Huynh, My Hang

    2010-06-22

    Lead-free primary explosives of the formula (cat)Y[MII(T)X(H2O)6-X]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.

  2. Type IA Supernova Explosion Models

    Microsoft Academic Search

    Wolfgang Hillebrandt; Jens C. Niemeyer

    2000-01-01

    Because calibrated light curves of type Ia supernovae have become a major tool to determine the local expansion rate of the universe and also its geometrical structure, considerable attention has been given to models of these events over the past couple of years. There are good reasons to believe that perhaps most type Ia supernovae are the explosions of white

  3. Fires and explosions in substations

    Microsoft Academic Search

    D. J. Allan

    2002-01-01

    As the age of transformers in substations increases, and as transformers are required to carry heavier overloads, the incidence of fires and explosions with oil-filled equipment has increased. Even 10 years ago most large users anticipated only one major fire every 5 years; current experience suggests that many users may suffer from more than one fire every year. Substations are

  4. Scientific and Technical Information Explosion.

    ERIC Educational Resources Information Center

    Emrich, Barry R.

    A concise review of statistics concerning the expanding volume and user needs of scientific and technical information is presented. It is intended to describe the magnitude of the so-called "information explosion" problem and illustrate how the various forms of communication play a role in meeting the needs of the technical community. Statistics…

  5. 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.

  6. 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.

  7. 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.

  8. Nuclear explosives testing readiness evaluation

    Microsoft Academic Search

    Valk

    1993-01-01

    This readiness evaluation considers hole selection and characterization, verification, containment issues, nuclear explosive safety studies, test authorities, event operations planning, canister-rack preparation, site preparation, diagnostic equipment setup, device assembly facilities and processes, device delivery and insertion, emplacement, stemming, control room activities, readiness briefing, arming and firing, test execution, emergency response and reentry, and post event analysis to include device diagnostics,

  9. 76 FR 8923 - Explosive Siting Requirements

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-16

    ...division 1.1 explosives and liquid propellants with trinitrotoluene (TNT) equivalents...reconcile its launch vehicle liquid propellant requirements with the presence of other...division 1.1 explosives and liquid propellants with TNT equivalency. The FAA...

  10. 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.

  11. Astrophysics: A lithium-rich stellar explosion

    NASA Astrophysics Data System (ADS)

    Hernanz, Margarita

    2015-02-01

    The contribution of explosions known as novae to the lithium content of the Milky Way is uncertain. Radioactive beryllium, which transforms into lithium, has been detected for the first time in one such explosion. See Letter p.381

  12. Experimental study of fuel-air explosive

    Microsoft Academic Search

    G. Liu; F. Hou; B. Cao; L. Xie; Zh. Shen; T. Zhou

    2008-01-01

    Experiments on an explosion of a fuel-air explosive (FAE) are carried out in open field, and comparative analyses between\\u000a solid fuels, liquid-solid fuels of different recipes, and TNT of the same mass are applied. The results show that the effect\\u000a of the FAE explosion at 3–6 m from the explosion center is definitely more pronounced than that of a TNT

  13. Characterization of secondary grain dust explosions

    E-print Network

    Schulman, Cheryl Wendler

    1983-01-01

    (Nember) Richard. B on en (Meshy) Edward A. Hiler (Head. of Department) AuSust 1983 Characterization of Secondary Grain Dust Explosions (August 15S3) Chsryl Wendler Schulman B. S. Texas AAN University Chairman of Advisory Committiee Dr. Calvin B.... Parnell, Jr. Presently, grain dust explosion research has been directed mainly into the mechanisms of the primary explosions with interest in the secondary explosion phenomena being virtually unrecord. ed. . Research 1n the area of' secondary grain...

  14. Experimental determination of detonation parameters of explosives based on ammonium nitrate

    NASA Astrophysics Data System (ADS)

    Utkin, Alexander; Lavrov, Vladimir; Mochalova, Valentina

    2011-06-01

    Laser interferometer VISAR was used for investigation of the reaction zone structure and determination of detonation parameters in two different kinds of explosives based on ammonium nitrate: emulsion explosives (EE) and composite explosives with plastic binder (CE). The influence of ammonium particle size, structure and diameter size of explosive charge on the detonation velocity and distribution of parameters inside the reaction zone has been investigated. It was found that detonation front of EE and CE is not smooth and a typical size of oscillations is determined by initial heterogeneity of explosives. Averaged profile of particle velocity fits with classic model of detonation and strongly pronounced Von Neumann spike is observed. Spike parameters are approximately 1.2 times greater than C-J parameters. The reaction time is order of microsecond. The detonation velocity of investigated explosives with initial density 1.1 g/cm^3 was changed from 4.5 to 5.0 km/s for EE and from 4.0 to 4.5 km/s for CE. The influence of aluminium and iron oxide additions on the detonation properties of CE was investigated.

  15. 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.

  16. 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.

  17. Explosives: A microsensor for trinitrotoluene vapour

    Microsoft Academic Search

    L. A. Pinnaduwage; A. Gehl; D. L. Hedden; G. Muralidharan; T. Thundat; R. T. Lareau; T. Sulchek; L. Manning; B. Rogers; M. Jones; J. D. Adams

    2003-01-01

    Sensing devices designed to detect explosive vapours are bulky, expensive and in need of technological improvement - dogs remain the most effective detectors in the fight against terrorism and in the removal of land-mines. Here we demonstrate the deflagration of trinitrotoluene (TNT) in a small localized explosion on an uncoated piezoresistive microcantilever. This explosive-vapour sensor, which has a detection capability

  18. 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.

  19. 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.

  20. Study on the effect of temperature rise on grain refining during fabrication of nanocrystalline copper under explosive loading

    NASA Astrophysics Data System (ADS)

    Wang, Jinxiang; Yang, Rui; Jiang, Li; Wang, Xiaoxu; Zhou, Nan

    2013-11-01

    Nanocrystalline (NC) copper was fabricated by severe plastic deformation of coarse-grained copper at a high strain rate under explosive loading. The feasibility of grain refinement under different explosive loading and the influence of overall temperature rise on grain refinement under impact compression were studied in this paper. The calculation model for the macroscopic temperature rise was established according to the adiabatic shock compression theory. The calculation model for coarse-grained copper was established by the Voronoi method and the microscopic temperature rise resulted from severe plastic deformation of grains was calculated by ANSYS/ls-dyna finite element software. The results show that it is feasible to fabricate NC copper by explosively dynamic deformation of coarse-grained copper and the average grain size of the NC copper can be controlled between 200˜400 nm. The whole temperature rise would increase with the increasing explosive thickness. Ammonium nitrate fuel oil explosive was adopted and five different thicknesses of the explosive, which are 20 mm, 25 mm, 30 mm, 35 mm, 45 mm, respectively, with the same diameter using 20 mm to the fly plate were adopted. The maximum macro and micro temperature rise is up to 532.4 K, 143.4 K, respectively, which has no great effect on grain refinement due to the whole temperature rise that is lower than grain growth temperature according to the high pressure melting theory.

  1. 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...

  2. Biodegradable Plastics from Cellulose

    Microsoft Academic Search

    Mariko Yoshioka; Nobuo Shiraishi

    2000-01-01

    Brief history of the attempts trying to develop biodegradable plastics from cellulose acetates were reviewed in the first part. Then, two kinds of authors' trials were introduced. One of them is a plasticization trial for cellulose acetates (CAs) that is based on the reaction with dibasic acid anhydrides and monoepoxides during melt processing under practical process conditions. This reactive melt-processing

  3. Biodegradation of plastics

    Microsoft Academic Search

    Masayuki Shimao

    2001-01-01

    Widespread studies on the biodegradation of plastics have been carried out in order to overcome the environmental problems associated with synthetic plastic waste. Recent work has included studies of the distribution of synthetic polymer-degrading microorganisms in the environment, the isolation of new microorganisms for biodegradation, the discovery of new degradation enzymes, and the cloning of genes for synthetic polymer-degrading enzymes.

  4. 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 ...

  5. Localization of plastic deformation

    Microsoft Academic Search

    J. Rice

    1976-01-01

    The localization of plastic deformation into a shear band is discussed as an instability of plastic flow and a precursor to rupture. Experimental observations are reviewed, a general theoretical framework is presented, and specific calculations of critical conditions are carried out for a variety of material models. The interplay between features of inelastic constitutive description, especially deviations from normality and

  6. STRESS AND HIPPOCAMPAL PLASTICITY

    Microsoft Academic Search

    Bruce S. McEwen

    1999-01-01

    The hippocampus is a target of stress hormones, and it is an especially plastic and vulnerable region of the brain. It also responds to gonadal, thyroid, and adrenal hormones, which modulate changes in synapse formation and dendritic structure and regulate dentate gyrus volume during development and in adult life. Two forms of structural plasticity are affected by stress: Repeated stress

  7. Plastic in the Pacific

    NSDL National Science Digital Library

    KQED

    2012-08-08

    Imagine every person on earth had 100 pounds of plastic. That's how much new plastic will be manufactured this year. In this video from QUEST produced by KQED, learn how much of that will end up in the ocean in a massive area dubbed the Pacific Garbage Patch.

  8. On the violence of thermal explosion in solid explosives

    Microsoft Academic Search

    Steven K. Chidester; Craig M. Tarver; Leroy G. Green; Paul A. Urtiew

    1997-01-01

    Twenty large scale experiments were conducted to determine the levels of violence of thermal explosions produced by various confinement and heat flow conditions. 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

  9. 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.

  10. Aspects of dynamic recrystallization in shaped charge and explosively formed projectile devices

    Microsoft Academic Search

    C. Feng; L. E. Murr; C.-S. Niou

    1996-01-01

    Under a shock wave, a shaped charge (SC) liner or an explosively formed projectile (EFP) device transforms into a jet and\\u000a a slug. At various laboratories, it was found that the transformation was closely related to extensive plastic flow occurring\\u000a at high strain rates. Along with the shape trans-formation, there is evidence of changes in hardness, strength, grain configuration,\\u000a microstructure,

  11. Development of a Simple Model of ``Hot-Spot'' Initiation in Heterogeneous Solid Explosives

    NASA Astrophysics Data System (ADS)

    Whitworth, N. J.

    2002-07-01

    Previously we numerically studied "hot-spot" formation in an explosive material as a result of shock induced pore collapse via microscale one-dimensional hydrocode simulations. Following this work, a simple model of the shock compaction process, leading to the formation and subsequent ignition of "hot-spots", has been developed for use in macroscale simulations of shock initiation problems of interest. The simple model is presented, where "hot-spots" are formed as a result of elastic-plastic and viscous stresses generated in the solid explosive during pore collapse. Results from the model are compared with corresponding results from the hydrocode simulations to illustrate how well, or otherwise, the simple model is performing. The model has also been used to help analyse data obtained from single and double shock initiation experiments on the HMX-based explosive PBX-9404.

  12. 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.

  13. Problems in the theory of point explosions

    NASA Astrophysics Data System (ADS)

    Korobeinikov, V. P.

    The book is concerned with the development of the theory of point explosions, which is relevant to the study of such phenomena as the initiation of detonation, high-power explosions, electric discharges, cosmic explosions, laser blasts, and hypersonic aerodynamics. The discussion covers the principal equations and the statement of problems; linearized non-self-similar one-dimensional problems; spherical, cylindrical, and plane explosions with allowance for counterpressure under conditions of constant initial density; explosions in a combustible mixture of gases; and point explosions in inhomogeneous media with nonsymmetric energy release. Attention is also given to point explosions in an electrically conducting gas with allowance for the effect of the magnetic field and to the propagation of perturbations from solar flares.

  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. Photographic laboratory studies of explosions.

    NASA Technical Reports Server (NTRS)

    Kamel, M. M.; Oppenheim, A. K.

    1973-01-01

    Description of a series of cinematographic studies of explosions made with a high-speed rotating-mirror streak camera which uses a high-frequency stroboscopic ruby laser as the light source. The results obtained mainly concern explosions initiated by focused laser irradiation from a pulsed neodymium laser in a detonating gas consisting essentially of an equimolar mixture of acetylene and oxygen at an initial pressure of 100 torr at room temperature. Among the most significant observations were observations of a spherical blast wave preceded by a Chapman-Jouguet detonation which is stabilized immediately after initiation, the merging of a spherical flame with a shock front of the blast wave in which the flame is propagating, the division of a spherical detonation front into a shock wave and flame, and the generation of shock waves by a network of spherical flames.

  16. Explosives detection system and method

    DOEpatents

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

    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.

  17. 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.

  18. 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.

  19. How explosive are volcanic eruptions?

    NASA Astrophysics Data System (ADS)

    Capuccini, F.; Perugini, D.; Alatorre-Ibarguengoitia, M. A.; Kueppers, U.; Dingwell, D. B.

    2009-12-01

    Population growth in the proximal areas of active and highly dangerous volcanoes is substantial. Despite improvements resulting in increasingly reliable monitoring methods, prediction of volcanic eruptions, both in terms of timing and eruptive style remains subject to major uncertainties. In order to obtain further insights into the eruptive behaviour of explosive volcanoes, we have been involved in investigating pyroclasts generated in laboratory experiments under controlled conditions. Seven sample sets from Unzen (Japan) and Popocatepetl (Mexico) volcanoes have been investigated in order to evaluate the influence of open porosity in combination with applied gas overpressure on the fragmentation behaviour and on the pyroclast generation (fragmentation efficiency). The Unzen samples are derived from block-and-ash flow deposits derived from dome collapse events; two Popocatepetl samples are ballistics from vulcanian eruptions, one sample was taken from a lava flow and the porous sample derives from a sub-plinian pyroclastic flow deposit. All experiments have been performed at well-controlled conditions of pressure, temperature and sample porosity. Using these shock tube based techniques we aim to simulate explosive volcanic eruptions driven by gas overpressure and investigated the grain-size distribution of experimentally generated pyroclasts. Fractal fragmentation theory was applied to each set of grain-size distribution by measuring the fractal dimension of fragmentation (Df). For each sample suite, a general linear increase of Df, i.e. the efficiency of fragmentation, with the potential energy for fragmentation was observed. Interestingly, the Df shows a positive correlation with open porosity for all investigated samples irrespective their origin. However and not surprisingly, some scattering was observed. This may be due to textural variability in the studied samples. It emerges from this study that fractal dimension may be utilised as a proxy for estimating the explosivity of volcanic eruptions by analysing their natural pyroclastic deposits. This may yield the opportunity to draw iso- Df or iso-explosivity contour maps based on fractal statistics. This possibility should be tested in the near future.

  20. 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

    ...DEPARTMENT OF LABOR Employment and Training Administration [TA-W-81,655] Carlyle Plastics and Resins, Formerly Known as Fortis Plastics, A Subsidiary of Plastics Acquisitions Inc., Including On-Site Leased Workers From Kelly Services...

  1. The Arson & Explosives National Repository

    NSDL National Science Digital Library

    The Arson & Explosives National Repository, hosted by the US Bureau of Alcohol, Tobacco, and Firearms(ATF), currently includes three database systems, providing statistics gathered by the ATF, the US Federal Bureau of Investigation (FBI), and the US Fire Administration (USFA). The first database, the Explosives Incident System (EXIS), contains several data tables that detail the arson and explosives incidents reported to the ATF from 1975 to 1995. The second database, the USFA's National Fire Incident Reporting System (NFIRS), provides the "world's largest national annual database of fire incident information." NFIRS offers annual data tables for a range of fire incidents from 1981 to 1995. The third database in the repository, Church Arson Task Force Data, presents data on church arsons and bombings from 1995 to 1997; data are displayed in tables, charts, and graphs. Besides providing a list of available data, each system allows users to conduct customizable queries. Within each system, users may search for incident data within a specified date range, or produce a five-year incident summary for any state in the US.

  2. 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.

  3. Overview on the structure, composition, function, development, and plasticity of hippocampal dendritic spines

    Microsoft Academic Search

    Karin E. Sorra; Kristen M. Harris

    2000-01-01

    There has been an explosion of new information on the neurobiology of dendritic spines in synaptic signaling, integration, and plasticity. Novel imaging and analytical techniques have provided impor- tant new insights into dendritic spine structure and function. Results are accumulating across many disciplines, and a step toward consolidating some of this work has resulted in Dendritic Spines of the Hippocampus.

  4. Coupled Damage and Plasticity Modelling in Transient Dynamic Analysis of Concrete

    E-print Network

    Paris-Sud XI, Université de

    Coupled Damage and Plasticity Modelling in Transient Dynamic Analysis of Concrete F. Gatuingt Abstract In a concrete structure subjected to an explosion, for example a concrete slab, the material on the same concrete. Computations of split Hopkinson tests on confined concrete, a tensile test with scabbing

  5. 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.

  6. Intravesical explosions during transurethral endoscopic procedures.

    PubMed

    Khan, A; Masood, J; Ghei, M; Kasmani, Z; Ball, A J; Miller, R

    2007-01-01

    Every Urologist, during the course of fulguration treatment of bladder tumours, has at some time or another experienced small intravesical explosions usually manifesting as a "pop". Major intravesical explosions are rare but potentially devastating complications of transurethral endoscopic resections. The damage to the bladder can range from small mucosal tears to bladder rupture, which can either be intraperitoneal (requiring laparotomy and open bladder repair) or extraperitoneal. We review the literature on intravesical explosions to determine the aetiology of these explosions and suggest strategies to prevent these. A comprehensive literature search was performed using Medline and Ovid to obtain information using search terms: intravesical explosions, transurethral procedures, endoscopic procedures, diathermyIntravesical explosions occur due to the production of explosive gases during use of diathermy on human tissues. The most dangerous combination is hydrogen and oxygen. Hydrogen alone is not explosive and it only becomes explosive when admixed with oxygen. Oxygen is not produced in sufficient quantity during diathermy to cause explosions but can enter into the bladder from the atmosphere during endoscopic procedures. Careful operative technique (correct use of the Ellick evacuator bulb and reducing the frequency of manual irrigations of the bladder) with minimisation of the operative time and using the coagulation current at moderate power as well as judicious coagulation of tissues can reduce the risk of this dangerous complication arising. PMID:17171415

  7. 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.

  8. Plastics Resource: Information on Plastics and the Environment

    NSDL National Science Digital Library

    The American Plastics Council (APC) maintains the Plastics Resource: Information on Plastics and the Environment Web site. The APC, which is a major trade association for the US plastics industry, works to promote the benefits of plastics and the plastics industry. Visitors to the site can learn the development history of plastics and how they contribute to our health and safety in the Plastics 101 link. They can also find out how plastics are actually environmentally friendly, how much they really contribute to landfills, how plastic can protect the groundwater, and much more. Although the site is well designed and enjoyable to explore, readers should understand the likely biases associated with organization presenting the information.

  9. Plastic Surgery for Teenagers

    MedlinePLUS

    ... Journal of the American Academy of Child & Adolescent Psychiatry 1995. 34:1637-1647. Simis, K.J., Hovius, S. ... applying for plastic surgery? Journal of Child Psychology & Psychiatry 2000; 42:669-678.

  10. Biomechanics Phenotypic plasticity in

    E-print Network

    Dabiri, John O.

    Biomechanics Phenotypic plasticity in juvenile jellyfish medusae facilitates effective animal and altered functionality. Previous studies have indicated that Scyphozoan jellyfish ontogeny accommo- dates; ontogeny; jellyfish 1. INTRODUCTION The swimming and feeding performance of marine ani- mals depends

  11. Plastic Race Car Competition

    NSDL National Science Digital Library

    WGBH Educational Foundation

    2010-07-11

    High school students learn about plastics technologies as they design and build car bodies for a remote-control race car competition in this video segment adapted from Pennsylvania College of Technology and WVIA.

  12. 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.)

  13. 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.

  14. DEPARTMENT OF PLASTIC SURGERY APPOINTMENTS,

    E-print Network

    DEPARTMENT OF PLASTIC SURGERY APPOINTMENTS, PROMOTION, AND TENURE DEPARTMENT OF PLASTIC SURGERY: 1/15/13 2 APPOINTMENTS, PROMOTION AND TENURE Criteria and Procedures for the DEPARTMENT OF PLASTIC: Department of Plastic Surgery Journal Rank List 73 Appendix 2: Statement on Professional Ethics 74 Approved

  15. Explosions

    MedlinePLUS

    ... kit to keep in your car in case you are told to evacuate. This kit should include: Copies of ... type of container to prevent leakage of contents. Never sniff or smell suspect mail. If you do not have a container, then cover the ...

  16. [Primary lesions caused by explosions].

    PubMed

    Pérez-Castanedo, J; Metje, M T; Vilaplana, J; Vizuete, G; March, X; García-Jiménez, M R

    1992-01-01

    The lesions produced by the expansive wave are characteristic of severe injury produced by explosion. This type of injury is being classified as primary lesion. We report a 28 years old male patient who suffered amputation of both lower extremities associated with hypovolemic shock. The patient presented primary tympanic perforation and pneumothorax after initiation of mechanical ventilation at positive pressure. In the discussion section we analyze the physical mechanisms leading to this primary lesion and we indicate the organs most commonly affected. We rise general considerations dealing with the management of these patients and we remark the advantages of a coordinated medical attendance policy. PMID:1598450

  17. 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 Scie

  18. Big Explosions and Strong Gravity

    NSDL National Science Digital Library

    2011-01-01

    This guide has been developed to assist people who would like to run the Big Explosions and Strong Gravity event with their local Girl Scout Council. The event is a one-day event in which a group of Girl Scouts spends their time doing a series of hands-on activities on spectroscopy, cosmic abundances, supernovae, and black holes. Professional scientists, engineers, and graduate students assist with these activities, giving the scouts a chance to interact with professionals in science and technology fields.

  19. Wireless sensor for detecting explosive material

    DOEpatents

    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.

  20. 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.

  1. Scaling explosive activity at Stromboli Volcano

    NASA Astrophysics Data System (ADS)

    marchetti, emanuele; ripepe, maurizio

    2013-04-01

    Ordinary explosive activity at Stromboli volcano is sometimes interrupted by Paroxysms and more often by Major Explosions. Major explosion represent a primary element of risk, given the large amount of material ejected, able to reach Pizzo Sopra la Fossa and the other summit trails, and the frequency of occurrence (2.1 events/year). However, while paroxysms are easy to be identified and there is a general consensous on their occurrence this does not necessarily hold for Major Explosions. Generally, Major Explosions are defined as based on the amount of material emitted and on the area covered by the ejecta dispersal, as well as on the properties of material emitted, but this is not always possible nor suitable for a near-real time information delivery to Civil Defence Authorities. With this purpose we have analyzed the seismic, tilt and infrasonic data collected at Stromboli since 2008 for a total database >400000 events to provide a geophysical classification of major explosions. We assumed that seismic (in the VLP band), ground tilt, and the acoustic excess pressure are efficient signals to discriminate different explosive energy. We show how ordinary activity is confined below a seismic VLP ground displacement of 8x10-6 m, a deformation of 0.25 ?rad and an infrasonic excess pressure of 100 Pa. A separate cluster of events, characterized by tilt and seismic displacement significantly larger than these threshold are defined as Major Explosions. Here we propose these threshold can be used to quantitatively discriminate between ordinary activity and Major explosions. While above these precise threshold we have several explosions which can be considered as Major Explosions, the two paroxysms are associated to orders of magnitude (ground displacement of 10-3 m and tilt of 10 ?rad) larger ground tilt and seismic VLP displacement. Besides our classification is suggesting the existence of a possible energy gap between Major and Paroxysms explosive dynamics which has not been filled yet.

  2. Nuclear Explosions Conducted for Peaceful Purposes

    Microsoft Academic Search

    Jun Takada

    \\u000a After 1963, when the Limited Test Ban Treaty went into effect, nuclear explosions were implemented near the surface of the\\u000a earth for “peaceful purposes” by the USA and the USSR.1) These nuclear explosions caused great amounts of nuclear pollution on the earth’s surface in addition to releasing much radioactive\\u000a material into the atmosphere. Approximately 100 “peaceful nuclear explosions” were conducted

  3. Omega Hydrodynamic Experiments that Simulate Jets in Supernova Explosions

    NASA Astrophysics Data System (ADS)

    Wilde, B. H.; Khokhlov, A. M.; Foster, J. M.; Rosen, P. A.; Perry, T. S.; Knauer, J. P.; Drake, R. P.; Gardner, J. H.; Remington, B. A.

    2002-11-01

    Recent observations of core collapse supernovae provide increasing evidence that supernova explosions are intrinsically asymmetric. An explosion model based on the assumption that bipolar, non-relativistic jets form during core collapse predicts an efficient ejection of a highly asymmetric supernova envelope and helps in understanding many of the observations (Khokhlov, et. al. ApJ 524, L107, 1999). Since the complex numerical hydrodynamic simulations of these jets require validation, we have designed a series of hydrodynamically-scaled jet experiments on the Omega laser at the University of Rochester. The jet in these experiments is formed by the laser ablation of the end of a cylinder of aluminum or magnesium that is imbedded in a gold washer. The plug is allowed to accelerate through a vacuum region in the washer and then enters into low-density foam as a jet. Several time-dependent transmission images are obtained by irradiating two large disks of titanium or silver that backlight the jet. In the supernova jet calculations, some of the material is accelerated to higher velocities in the equatorial plane (perpendicular to the bipolar jet) by a Mach ring formation. To study this effect, we have fielded experiments that create a Mach ring by the collision of two plates of aluminum that have been accelerated towards each other into a CH plastic. The Mach ring forms in the CH plastic and several radiographs were obtained. We will compare the jet and Mach ring data to simulations done with the LANL RAGE, the AWE NYM/PETRA, and the NRL ALLA codes.*This work is performed under the auspices of the U. S. Department of Energy by the Los Alamos National Laboratory Laboratory under Contract No. W-7405-ENG-36, Lawrence Livermore National Laboratory under Contract No. W-7405-ENG-48, the Laboratory for Laser Energetics under Contract No. DE-FC03-92SF19460, the Office of Naval Research, and the NASA Astrophysical Theory Grant.

  4. Reverse shock wave in relativistic explosions

    NASA Astrophysics Data System (ADS)

    Yokosawa, M.

    1984-12-01

    The dynamical evolution of a relativistic explosion in a homogeneous medium is studied by means of a time-dependent, hydrodynamic code. When the expanding velocity of the shock front reduces to the sound velocity in the relativistic fluid, the reverse shock wave propagating inward through the expanding material is generated. The radius of the turning point of the reverse shock wave is proportional to the explosion energy and hardly depends on the mass of the explosion products. In the case of the non-relativistic explosion, the reverse shock wave is generated just after the free expansion stage. The radius of the turning point of the reverse shock wave is proportional to the mass of the explosion products and little depends on the explosion energy. In both cases of the non-relativistic and relativistic explosion, the reverse shock wave is strong in a spherical explosion and weak in a cylindrical one. The plane symmetric explosion does not generate the reverse shock wave.

  5. Method and apparatus for detecting explosives

    SciTech Connect

    Moore, David Steven (Santa Fe, NM)

    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.

  6. Momentum transfer in indirect explosive drive

    SciTech Connect

    Kennedy, J.E.; Warnes, R.H. [Los Alamos National Lab., NM (United States); Cherry, C.R.; Cherry, C.R. Jr.; Fischer, S.H. [Sandia National Labs., Albuquerque, NM (United States)

    1996-07-01

    Material which is not in direct contact with detonating explosives may still be driven by the explosion through impact by driven material or by attachment to driven material. In such circumstances the assumption of inelastic collision permits estimation of the final velocity of an assemblage. Examples of the utility of this assumption are demonstrated through use of Gurney equations. The inelastic collision calculation may also be used for metal parts which are driven by explosives partially covering the metal. We offer a new discounting angle to account for side energy losses from laterally unconfined explosive charges in cases where the detonation wave travels parallel to the surface which is driven.

  7. 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.

  8. 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

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

    SciTech Connect

    Einfeld, W.; Morrison, D.J. [Sandia National Labs., Albuquerque, NM (United States); Mullins, S.E. [Alliant Techsystems, Inc., Rocket Center, WV (United States)

    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.

  10. Explosive double salts and preparation

    DOEpatents

    Cady, Howard H. (Los Alamos, NM); Lee, Kien-yin (Los Alamos, NM)

    1984-01-01

    Applicants have discovered a new composition of matter which is an explosive addition compound of ammonium nitrate (AN) and diethylenetriamine trinitrate (DETN) in a 50:50 molar ratio. The compound is stable over extended periods of time only at temperatures higher than 46.degree. C., decomposing to a fine-grained eutectic mixture (which is also believed to be new) of AN and DETN at temperatures lower than 46.degree. C. The compound of the invention has an x-ray density of 1.61 g/cm.sup.3, explodes to form essentially only gaseous products, has higher detonation properties (i.e., detonation velocity and pressure) than those of any mechanical mixture having the same density and composition as the compound of the invention, is a quite insensitive explosive material, can be cast at temperatures attainable by high pressure steam, and is prepared from inexpensive ingredients. Methods of preparing the compound of the invention and the fine-grained eutectic composition of the invention are given.

  11. Conference Summary: Three Dimensional Explosions

    E-print Network

    J. Craig Wheeler

    2004-01-15

    This is the text of a summary of the workshop on asymmetric explosions held in Austin in June, 2003. A brief review is given of the author's own interests in dynamo theory as it may apply in the core collapse ambience. Of particular interest are saturation fields for the cases with central neutron stars and black holes and the possibility of driving MHD jets with the resulting fields. Interesting physics that may arise with large fields such as effects on the equation of state to produce anisotropic pressure and effects on neutrino cross sections and transport are briefly outlined. A brief summary of the contributions to the workshop is then given with special credit to Scratchy Serapkin. Of special note were the summaries of the advances due to spectropolarimetry in revealing the asymmetric nature of supernovae. Major progress in understanding the binary progenitors and explosion physics of Type Ia was presented. Other talks entwined the nature of asymmetric core collapse, gamma-ray bursts and "hypernovae." My final charge to the attendees was "Go thee forth and think about rotation and magnetic fields!"

  12. High temperature two component explosive

    DOEpatents

    Mars, James E. (Vashon, WA); Poole, Donald R. (Woodinville, WA); Schmidt, Eckart W. (Bellevue, WA); Wang, Charles (Lafayette, IN)

    1981-01-01

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

  13. Dust explosions–Cases, causes, consequences, and control

    Microsoft Academic Search

    Tasneem Abbasi; S. A. Abbasi

    2007-01-01

    Dust explosions pose the most serious and widespread of explosion hazards in the process industry alongside vapour cloud explosions (VCE) and boiling liquid expanding vapour explosions (BLEVE). Dust explosions almost always lead to serious financial losses in terms of damage to facilities and down time. They also often cause serious injuries to personnel, and fatalities.We present the gist of the

  14. Cosmic Explosions in Three Dimensions

    NASA Astrophysics Data System (ADS)

    Höflich, Peter; Kumar, Pawan; Wheeler, J. Craig

    2011-08-01

    Introduction: 3-D Explosions: a meditation on rotation (and magnetic fields) J. C. Wheeler; Part I. Supernovae: Observations Today: 1. Supernova explosions: lessons from spectropolarimetry L. Wang; 2. Spectropolarimetric observations of Supernovae A. Filippenko and D. C. Leonard; 3. Observed and physical properties of type II plateau supernovae M. Hamuy; 4. SN1997B and the different types of Type Ic Supernovae A. Clocchiatti, B. Leibundgut, J. Spyromilio, S. Benetti, E. Cappelaro, M. Turatto and M. Phillips; 5. Near-infrared spectroscopy of stripped-envelope Supernovae C. L. Gerardy, R. A. Fesen, G. H. Marion, P. Hoeflich and J. C. Wheeler; 6. Morphology of Supernovae remnants R. Fesen; 7. The evolution of Supernova remnants in the winds of massive stars V. Dwarkadas; 8. Types for the galactic Supernovae B. E. Schaefer; Part II. Theory of Thermonuclear Supernovae: 9. Semi-steady burning evolutionary sequences for CAL 83 and CAL 87: supersoft X-ray binaries are Supernovae Ia progenitors S. Starrfield, F. X. Timmes, W. R. Hix, E. M. Sion, W. M. Sparks and S. Dwyer; 10. Type Ia Supernovae progenitors: effects of the spin-up of the white dwarfs S.-C. Yoon and N. Langer; 11. Terrestrial combustion: feedback to the stars E. S. Oran; 12. Non-spherical delayed detonations E. Livne; 13. Numerical simulations of Type Ia Supernovae: deflagrations and detonations V. N. Gamezo, A. M. Khokhlov and E. S. Oran; 14. Type Ia Supernovae: spectroscopic surprises D. Branch; 15. Aspherity effects in Supernovae P. Hoeflich, C. Gerardy and R. Quimby; 16. Broad light curve SneIa: asphericity or something else? A. Howell and P. Nugent; 17. Synthetic spectrum methods for 3-D SN models R. Thomas; 18. A hole in Ia' spectroscopic and polarimetric signatures of SN Ia asymmetry due to a companion star D. Kasen; 19. Hunting for the signatures of 3-D explosions with 1-D synthetic spectra E. Lentz, E. Baron and P. H. Hauschildt; 20. On the variation of the peak luminosity of Type Ia J. W. Truran, E. X. Timmes and E. F. Brown; Part III. Theory of Core Collapse Supernovae: 21. Rotation of core collapse progenitors: single and binary stars N. Langer; 22. Large scale convection and the convective Supernova mechanism S. Colgate and M. E. Herant; 23. Topics in core-collapse Supernova A. Burrows, C. D. Ott and C. Meakin; 24. MHD Supernova jets: the missing link D. Meier and M. Nakamura; 25. Effects of super strong magnetic fields in core collapse Supernovae I. S. Akiyama; 26. Non radial instability of stalled accretion shocks advective-acoustic cycle T. Foglizzo and P. Galletti; 27. Asymmetry effects in Hypernovae K. Maeda, K. Nomoto, J. Deng and P.A. Mazzali; 28. Turbulent MHD jet collimation and thermal driving P. T. Williams; Part IV. Magnetars, N-Stars, Pulsars: 29. Supernova remnants and pulsar wind nebulae R. Chevalier; 30. X-Ray signatures of Supernovae D. Swartz; 31. Asymmetric Supernovae and Neutron Star Kicks D. Lai and D. Q. Lamb; 32. Triggers of magnetar outbursts R. Duncan; 33. Turbulent MHD Jet Collimation and Thermal Driving P. Williams; 34. The interplay between nuclear electron capture and fluid dynamics in core collapse Supernovae W. R. Hix, O. E. B. Messer and A. Mezzacappa; Part V. Gamma-Ray Bursts: 35. GRB 021004 and Gamma-ray burst distances B. E. Schaefer; 36. Gamma-ray bursts as a laboratory for the study of Type Ic Supernovae D. Q. Lamb, T. Q. Donaghy and C. Graziani; 37. The diversity of cosmic explosions: Gamma-ray bursts and Type Ib/c Supernovae E. Berger; 38. A GRB simulation using 3D relativistic hydrodynamics J. Cannizo, N. Gehrels and E. T. Vishniac; 39. The first direct link in the Supernova/GRB connection: GRB 030329 and SN 2003dh T. Matheson; Part VI. Summary: 40. Three-dimensional explosions C. Wheeler.

  15. Cosmic Explosions in Three Dimensions

    NASA Astrophysics Data System (ADS)

    Höflich, Peter; Kumar, Pawan; Wheeler, J. Craig

    2004-12-01

    Introduction: 3-D Explosions: a meditation on rotation (and magnetic fields) J. C. Wheeler; Part I. Supernovae: Observations Today: 1. Supernova explosions: lessons from spectropolarimetry L. Wang; 2. Spectropolarimetric observations of Supernovae A. Filippenko and D. C. Leonard; 3. Observed and physical properties of type II plateau supernovae M. Hamuy; 4. SN1997B and the different types of Type Ic Supernovae A. Clocchiatti, B. Leibundgut, J. Spyromilio, S. Benetti, E. Cappelaro, M. Turatto and M. Phillips; 5. Near-infrared spectroscopy of stripped-envelope Supernovae C. L. Gerardy, R. A. Fesen, G. H. Marion, P. Hoeflich and J. C. Wheeler; 6. Morphology of Supernovae remnants R. Fesen; 7. The evolution of Supernova remnants in the winds of massive stars V. Dwarkadas; 8. Types for the galactic Supernovae B. E. Schaefer; Part II. Theory of Thermonuclear Supernovae: 9. Semi-steady burning evolutionary sequences for CAL 83 and CAL 87: supersoft X-ray binaries are Supernovae Ia progenitors S. Starrfield, F. X. Timmes, W. R. Hix, E. M. Sion, W. M. Sparks and S. Dwyer; 10. Type Ia Supernovae progenitors: effects of the spin-up of the white dwarfs S.-C. Yoon and N. Langer; 11. Terrestrial combustion: feedback to the stars E. S. Oran; 12. Non-spherical delayed detonations E. Livne; 13. Numerical simulations of Type Ia Supernovae: deflagrations and detonations V. N. Gamezo, A. M. Khokhlov and E. S. Oran; 14. Type Ia Supernovae: spectroscopic surprises D. Branch; 15. Aspherity effects in Supernovae P. Hoeflich, C. Gerardy and R. Quimby; 16. Broad light curve SneIa: asphericity or something else? A. Howell and P. Nugent; 17. Synthetic spectrum methods for 3-D SN models R. Thomas; 18. A hole in Ia' spectroscopic and polarimetric signatures of SN Ia asymmetry due to a companion star D. Kasen; 19. Hunting for the signatures of 3-D explosions with 1-D synthetic spectra E. Lentz, E. Baron and P. H. Hauschildt; 20. On the variation of the peak luminosity of Type Ia J. W. Truran, E. X. Timmes and E. F. Brown; Part III. Theory of Core Collapse Supernovae: 21. Rotation of core collapse progenitors: single and binary stars N. Langer; 22. Large scale convection and the convective Supernova mechanism S. Colgate and M. E. Herant; 23. Topics in core-collapse Supernova A. Burrows, C. D. Ott and C. Meakin; 24. MHD Supernova jets: the missing link D. Meier and M. Nakamura; 25. Effects of super strong magnetic fields in core collapse Supernovae I. S. Akiyama; 26. Non radial instability of stalled accretion shocks advective-acoustic cycle T. Foglizzo and P. Galletti; 27. Asymmetry effects in Hypernovae K. Maeda, K. Nomoto, J. Deng and P.A. Mazzali; 28. Turbulent MHD jet collimation and thermal driving P. T. Williams; Part IV. Magnetars, N-Stars, Pulsars: 29. Supernova remnants and pulsar wind nebulae R. Chevalier; 30. X-Ray signatures of Supernovae D. Swartz; 31. Asymmetric Supernovae and Neutron Star Kicks D. Lai and D. Q. Lamb; 32. Triggers of magnetar outbursts R. Duncan; 33. Turbulent MHD Jet Collimation and Thermal Driving P. Williams; 34. The interplay between nuclear electron capture and fluid dynamics in core collapse Supernovae W. R. Hix, O. E. B. Messer and A. Mezzacappa; Part V. Gamma-Ray Bursts: 35. GRB 021004 and Gamma-ray burst distances B. E. Schaefer; 36. Gamma-ray bursts as a laboratory for the study of Type Ic Supernovae D. Q. Lamb, T. Q. Donaghy and C. Graziani; 37. The diversity of cosmic explosions: Gamma-ray bursts and Type Ib/c Supernovae E. Berger; 38. A GRB simulation using 3D relativistic hydrodynamics J. Cannizo, N. Gehrels and E. T. Vishniac; 39. The first direct link in the Supernova/GRB connection: GRB 030329 and SN 2003dh T. Matheson; Part VI. Summary: 40. Three-dimensional explosions C. Wheeler.

  16. Low Frequency Electromagnetic Pulse and Explosions

    SciTech Connect

    Sweeney, J J

    2011-02-01

    This paper reviews and summarizes prior work related to low frequency (< 100 Hz) EMP (ElectroMagnetic Pulse) observed from explosions. It focuses on how EMP signals might, or might not, be useful in monitoring underground nuclear tests, based on the limits of detection, and physical understanding of these signals. In summary: (1) Both chemical and nuclear explosions produce an EMP. (2) The amplitude of the EMP from underground explosions is at least two orders of magnitude lower than from above ground explosions and higher frequency components of the signal are rapidly attenuated due to ground conductivity. (3) In general, in the near field, that is distances (r) of less than 10s of kilometers from the source, the amplitude of the EMP decays approximately as 1/r{sup 3}, which practically limits EMP applications to very close (<{approx}1km) distances. (4) One computational model suggests that the EMP from a decoupled nuclear explosion may be enhanced over the fully coupled case. This has not been validated with laboratory or field data. (5) The magnitude of the EMP from an underground nuclear explosion is about two orders of magnitude larger than that from a chemical explosion, and has a larger component of higher frequencies. In principle these differences might be used to discriminate a nuclear from a chemical explosion using sensors at very close (<{approx}1 km) distances. (6) Arming and firing systems (e.g. detonators, exploding bridge wires) can also produce an EMP from any type of explosion. (7) To develop the understanding needed to apply low frequency EMP to nuclear explosion monitoring, it is recommended to carry out a series of controlled underground chemical explosions with a variety of sizes, emplacements (e.g. fully coupled and decoupled), and arming and firing systems.

  17. 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.

  18. 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

  19. Explosive laser light initiation of propellants

    DOEpatents

    Piltch, M.S.

    1993-05-18

    A improved initiator for artillery shell using an explosively generated laser light to uniformly initiate the propellent. A small quantity of a high explosive, when detonated, creates a high pressure and temperature, causing the surrounding noble gas to fluoresce. This fluorescence is directed into a lasing material, which lases, and directs laser light into a cavity in the propellant, uniformly initiating the propellant.

  20. Glass produced by underground nuclear explosions. [Rainier

    SciTech Connect

    Schwartz, L.; Piwinskii, A.; Ryerson, F.; Tewes, H.; Beiriger, W.

    1983-01-01

    Detonation of an underground nuclear explosive produces a strong shock wave which propagates spherically outward, vaporizing the explosive and nearby rock and melting, the surrounding rock. The vaporized material expands adiabatically, forming a cavity. As the energy is dissipated during the cavity formation process, the explosive and rock debris condense and mix with the melted rock. The melt flows to the bottom of the cavity where it is quenched by fractured rock fragments falling from above as the cavity collapses. Measurements indicate that about 740 tonnes of rock and/or soil are melted for every kiloton (10/sup 12/ calories) of explosive energy, or about 25% of the explosive energy goes to melting rock. The resulting glass composition reflects the composition of the unaltered rock with explosive debris. The appearance ranges from white pumice to dense, dark lava. The bulk composition and color vary with the amount of explosive iron incorporated into the glass. The refractory explosion products are mixed with the solidified melt, although the degree of mixing is variable. Electron microprobe studies of glasses produced by Rainier in welded tuff have produced the following results: glasses are dehydrated relative to the host media, glasses are extremely heterogeneous on a 20 ..mu..m scale, a ubiquitous feature is the presence of dark marble-cake regions in the glass, which were locally enriched in iron and may be related to the debris, optically amorphous regions provide evidence of shock melting, only limited major element redistribution and homogenization occur within the cavity.

  1. Advancing Explosives Detection Capabilities: Vapor Detection

    SciTech Connect

    Atkinson, David

    2012-10-15

    A new, PNNL-developed method provides direct, real-time detection of trace amounts of explosives such as RDX, PETN and C-4. The method selectively ionizes a sample before passing the sample through a mass spectrometer to detect explosive vapors. The method could be used at airports to improve aviation security.

  2. Investigation of an air separation unit explosion

    Microsoft Academic Search

    R. M. van Hardeveld; M. J. Groeneveld; J.-Y. Lehman; D. C. Bull

    2001-01-01

    This paper describes the investigation of the cause of a serious explosion in an air separation unit in Bintulu (Malaysia) on 25 December 1997. Since the cause of the explosion was not obvious, a large number of possible scenarios was generated, followed by a systematic process of elimination. Ultimately, conclusive evidence was obtained that combustible airborne particulates had passed the

  3. Explosive Joining for Nuclear-Reactor Repair

    NASA Technical Reports Server (NTRS)

    Bement, L. J.; Bailey, J. W.

    1983-01-01

    In explosive joining technique, adapter flange from fuel channel machined to incorporate a V-notch interface. Ribbon explosive, 1/2 inch (1.3 cm) in width, drives V-notched wall of adapter into bellows assembly, producing atomic-level metallurgical bond. Ribbon charge yields joint with double parent metal strength.

  4. Supra-Pressure Detonation of Aluminized Explosive

    Microsoft Academic Search

    Ronald Brown; B. Karosich; J. Gamble; J. Stork; A. Biesterveld; T. Moore; J. Sinibaldi; M. Walpole; A. Lindfors; K. Jackson; R. Koontz; D. Thompson

    2007-01-01

    Results suggest that there is a continuum of reactions induced behind a supra-pressure convergent shock front in explosive cores of coaxial charges. The pressures in convergent fronts continually increase at an increasing rate from the circumference to the charge axis. Furthermore the unreacted explosive enveloped within the front is pre-pressurized at Von Neumann states much greater than from divergent detonation.

  5. Explosion welding and cutting in aerospace engineering

    Microsoft Academic Search

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

    1991-01-01

    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

  6. Method for laser machining explosives and ordnance

    DOEpatents

    Muenchausen, Ross E.; Rivera, Thomas; Sanchez, John A.

    2003-05-06

    Method for laser machining explosives and related articles. A laser beam is directed at a surface portion of a mass of high explosive to melt and/or vaporize the surface portion while directing a flow of gas at the melted and/or vaporized surface portion. The gas flow sends the melted and/or vaporized explosive away from the charge of explosive that remains. The method also involves splitting the casing of a munition having an encased explosive. The method includes rotating a munition while directing a laser beam to a surface portion of the casing of an article of ordnance. While the beam melts and/or vaporizes the surface portion, a flow of gas directed at the melted and/or vaporized surface portion sends it away from the remaining portion of ordnance. After cutting through the casing, the beam then melts and/or vaporizes portions of the encased explosive and the gas stream sends the melted/vaporized explosive away from the ordnance. The beam is continued until it splits the article, after which the encased explosive, now accessible, can be removed safely for recycle or disposal.

  7. Advancing Explosives Detection Capabilities: Vapor Detection

    ScienceCinema

    Atkinson, David

    2014-07-24

    A new, PNNL-developed method provides direct, real-time detection of trace amounts of explosives such as RDX, PETN and C-4. The method selectively ionizes a sample before passing the sample through a mass spectrometer to detect explosive vapors. The method could be used at airports to improve aviation security.

  8. Fire and explosion hazards of oil shale

    SciTech Connect

    Not Available

    1989-01-01

    The US Bureau of Mines publication presents the results of investigations into the fire and explosion hazards of oil shale rocks and dust. Three areas have been examined: the explosibility and ignitability of oil shale dust clouds, the fire hazards of oil shale dust layers on hot surfaces, and the ignitability and extinguishment of oil shale rubble piles. 10 refs., 54 figs., 29 tabs.

  9. Mathematical theory of combustion and explosions

    Microsoft Academic Search

    I. A. B. Zeldovich; G. I. Barenblatt; V. B. Librovich; G. M. Makhviladze

    1985-01-01

    Various topics in the area of combustion and explosives are discussed. The general subjects considered include: basic physical concepts of the science of combustion, the time-independent theory of thermal explosions, time-dependent statement of the problem of the initiation of chemical reaction waves in fuel mixtures, laminar flames, complex and chain reactions in flames, the gas dynamics of combustion, and diffusional

  10. Asymmetric explosion of core collapse supernovae

    Microsoft Academic Search

    T. Foglizzo; J. Guilet; J. Sato

    2009-01-01

    The explosion of most massive stars depends on the revival of a stalled shock, a few hundred milliseconds after the birth of the central neutron star. Recent numerical simulations suggest that this revival is possible through an asymmetric explosion helped by a hydrodynamical instability named SASI. Its asymmetric character is also able to influence the kick and the spin of

  11. A POWER EXPLOSIBILITY TESTER WITH CONTINUOUS FEED

    Microsoft Academic Search

    Box

    1959-01-01

    A system for continuous testing the explosibility of powdered materials ; was developed. The limits of concentration of powder in air within which ; explosions occur can be simply and repeatably determined by continuously varying ; the flow ratio of sample to air until the mixture ignites. A precision of plus ; or minus 0.007 g sample per liter of

  12. Transition of porous explosive combustion into detonation

    Microsoft Academic Search

    I. Sh. Akhatov; P. B. Vainshtein

    1984-01-01

    This article considers the planar one-dimensional motion of a porous medium consisting of solid contacting particles (explosive grains), with space between particles filled with gas. It is established by the numerical analysis performed that if the work of intergranular pressure forces is expended solely in gas heating, then a smooth transition from combustion to detonation is realized in porous explosives.

  13. The 1908 Tunguska Explosion and Its Analogs

    Microsoft Academic Search

    Subhon Ibadov; Firuz S. Ibodov; Samvel S. Grigoryan

    2008-01-01

    The 1908 June 30 Tunguska explosion event, which occured one hundred years ago, is analysed together with the origin of such explosive events as flaring meteors, exploding bolides and some kind of solar flares. These events are explained analytically by aerodynamic fragmentation of cosmic bodies like comets, asteroids, meteoroids in the atmospheres of celestial objects accompanied by transversal expansion of

  14. Energetic Trend in Explosive Activity of Stromboli

    NASA Astrophysics Data System (ADS)

    Coltelli, M.; Cristaldi, A.; Mangiagli, S.; Nunnari, G.; Pecora, E.

    2003-12-01

    The typical activity of Stromboli consists of intermittent mild explosions lasting a few seconds, which take place at different vents and at variable intervals, the most common time interval being 10-20 minutes. However, the routine activity can be interrupted by more violent, paroxysmal explosions, that eject m-sized scoriaceous bombs and lava blocks to a distance of several hundreds of meters from the craters, endangering the numerous tourists that watch the spectacular activity from the volcano's summit located about two hundreds meters from the active vents. On average, 1-2 paroxysmal explosions occurred per year over the past century, but this statistic may be underestimated in absence of continuous monitoring. For this reason from summer 1996 a remote surveillance camera works on Stromboli recording continuously the volcanic activity. It is located on Pizzo Sopra la Fossa, 100 metres above the crater terrace where are the active vents. Using image analysis we seeks to identify any change of the explosive activity trend that could precede a particular eruptive event, like paroxysmal explosions, fire fountains, lava flows. The analysis include the counting of the explosions occurred at the different craters and the parameterization in classes of intensity for each explosion on the base of tephra dispersion and kinetics energy. Associating at each class a corresponding Index of energy in order to compute an heuristic value of the Average Daily Energy Released (ADER) of the explosive activity at Stromboli and plotting this value for each crater versus time, the diagram shows a cyclic behavior with max and min of explosive activity ranging from a few days to a month. Often the craters show opposite trends so when the activity decreases in a crater, increases in the other. Before every paroxysmal explosions recorded, the crater that produced the event decreased and then stopped its activity from a few days to weeks before. The other crater tried to compensate increasing its activity and when it declined the paroxysmal explosion occurred suddenly at the former site. From September 2001 an on-line image analyzer called VAMOS (Volcanic Activity MOnitoring System) operates detection and classification of explosive events in real-time. The system has automatically recorded and analyzed the change in the energetic trend that preceded the 20 October 2001 paroxysmal explosion that killed a woman and the strong explosive activity that preceded the onset of 28 December 2002 lava flow eruption.

  15. Plastic heliostat enclosure analysis

    NASA Astrophysics Data System (ADS)

    Berry, M. J.

    1984-12-01

    The conceptual design and cost analysis of an enclosed plastic heliostat for a 50-MW/sub e/ central receiver solar thermal electric power plant are presented. The purpose of the study was to analyze the most recent design of the Boeing enclosed plastic heliostat for cost and compare results with a reference second generation glass heliostat case provided by Sandia National Laboratories, Livermore. In addition, sensitivities of busbar energy costs to variations in capital cost (installed cost), operation and maintenance most and overall reflectivity were evaluated.

  16. Understanding ultrafine nanodiamond formation using nanostructured explosives

    PubMed Central

    Pichot, Vincent; Risse, Benedikt; Schnell, Fabien; Mory, Julien; Spitzer, Denis

    2013-01-01

    The detonation process is able to build new materials with a bottom-up approach. Diamond, the hardest material on earth, can be synthesized in this way. This unconventional synthesis route is possible due to the presence of carbon inside the high-explosive molecules: firing high-explosive mixtures with a negative oxygen balance in a non-oxidative environment leads to the formation of nanodiamond particles. Trinitrotoluene (TNT) and hexogen (RDX) are the explosives primarily used to synthesize nanodiamonds. Here we show that the use of nanostructured explosive charges leads to the formation of smaller detonation nanodiamonds, and it also provides new understanding of nanodiamond formation-mechanisms. The discontinuity of the explosive at the nanoscale level plays the key role in modifying the diamond particle size, and therefore varying the size with microstructured charges is impossible. PMID:23831716

  17. [Explosion injuries - prehospital care and management].

    PubMed

    Holsträter, Thorsten; Holsträter, Susanne; Rein, Daniela; Helm, Matthias; Hossfeld, Björn

    2013-11-01

    Explosion injuries are not restricted to war-like military conflicts or terrorist attacks. The emergency physician may also encounter such injuries in the private or industrial fields, injuries caused by fireworks or gas explosions. In such cases the injury patterns are especially complex and may consist of blunt and penetrating injuries as well as thermal damage. Emergency medical personnel must be prepared to cope with explosion trauma not only in individual cases but also in major casualty incidents (MCI). This necessitates a sound knowledge about the mechanisms and processes of an explosion as well as the particular pathophysiological relationships of explosion injuries in order to be able to initiate the best possible, guideline-conform trauma therapy. PMID:24343140

  18. Independence day explosion on lovers key.

    PubMed

    Harding, Brett A; Wolf, Barbara C

    2007-09-01

    The display of fireworks is a popular holiday celebration in the United States. Because injuries due to recreational fireworks-related explosions among private consumers are relatively common, the sale of fireworks is regulated by the federal government and is also limited by state and local laws. In contrast, because fireworks display companies are under tight safety regulations, explosions in the professional pyrotechnics industry are uncommon occurrences, and the literature contains rare reports of injuries and fatalities resulting from such explosions. We report the 2003 Fourth of July commercial fireworks explosion on Lovers Key in southwest Florida that resulted in five fatalities. Events occurring during the investigation of the scene of this explosion illustrate the unique considerations and hazards for medicolegal death investigators, law enforcement and other investigative agencies. Additionally, this case demonstrates unusual aspects of the postmortem examinations performed on victims of fireworks-related incidents. PMID:17767662

  19. Explosives remain preferred methods for platform abandonment

    SciTech Connect

    Pulsipher, A.; Daniel, W. IV [Louisiana State Univ., Baton Rouge, LA (United States); Kiesler, J.E. [Kiesler (James E.), Morgan City, LA (United States); Mackey, V. III [Chevron Petroleum Technology Co., Houston, TX (United States)

    1996-05-06

    Economics and safety concerns indicate that methods involving explosives remain the most practical and cost-effective means for abandoning oil and gas structures in the Gulf of Mexico. A decade has passed since 51 dead sea turtles, many endangered Kemp`s Ridleys, washed ashore on the Texas coast shortly after explosives helped remove several offshore platforms. Although no relationship between the explosions and the dead turtles was ever established, in response to widespread public concern, the US Minerals Management Service (MMS) and National Marine Fisheries Service (NMFS) implemented regulations limiting the size and timing of explosive charges. Also, more importantly, they required that operators pay for observers to survey waters surrounding platforms scheduled for removal for 48 hr before any detonations. If observers spot sea turtles or marine mammals within the danger zone, the platform abandonment is delayed until the turtles leave or are removed. However, concern about the effects of explosives on marine life remains.

  20. 30 CFR 56.20009 - Tests for explosive dusts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Tests for explosive dusts. 56.20009 Section 56.20009 Mineral Resources... Miscellaneous § 56.20009 Tests for explosive dusts. Dusts suspected of being explosive shall be tested for...

  1. 30 CFR 57.20009 - Tests for explosive dusts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Tests for explosive dusts. 57.20009 Section 57.20009 Mineral Resources... Miscellaneous § 57.20009 Tests for explosive dusts. Dusts suspected of being explosive shall be tested for...

  2. 30 CFR 56.20009 - Tests for explosive dusts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Tests for explosive dusts. 56.20009 Section 56.20009 Mineral Resources... Miscellaneous § 56.20009 Tests for explosive dusts. Dusts suspected of being explosive shall be tested for...

  3. 30 CFR 56.20009 - Tests for explosive dusts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Tests for explosive dusts. 56.20009 Section 56.20009 Mineral Resources... Miscellaneous § 56.20009 Tests for explosive dusts. Dusts suspected of being explosive shall be tested for...

  4. 30 CFR 56.20009 - Tests for explosive dusts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Tests for explosive dusts. 56.20009 Section 56.20009 Mineral Resources... Miscellaneous § 56.20009 Tests for explosive dusts. Dusts suspected of being explosive shall be tested for...

  5. 30 CFR 57.20009 - Tests for explosive dusts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Tests for explosive dusts. 57.20009 Section 57.20009 Mineral Resources... Miscellaneous § 57.20009 Tests for explosive dusts. Dusts suspected of being explosive shall be tested for...

  6. 30 CFR 57.20009 - Tests for explosive dusts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Tests for explosive dusts. 57.20009 Section 57.20009 Mineral Resources... Miscellaneous § 57.20009 Tests for explosive dusts. Dusts suspected of being explosive shall be tested for...

  7. 30 CFR 57.20009 - Tests for explosive dusts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Tests for explosive dusts. 57.20009 Section 57.20009 Mineral Resources... Miscellaneous § 57.20009 Tests for explosive dusts. Dusts suspected of being explosive shall be tested for...

  8. 30 CFR 56.20009 - Tests for explosive dusts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Tests for explosive dusts. 56.20009 Section 56.20009 Mineral Resources... Miscellaneous § 56.20009 Tests for explosive dusts. Dusts suspected of being explosive shall be tested for...

  9. 30 CFR 57.20009 - Tests for explosive dusts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Tests for explosive dusts. 57.20009 Section 57.20009 Mineral Resources... Miscellaneous § 57.20009 Tests for explosive dusts. Dusts suspected of being explosive shall be tested for...

  10. 30 CFR 57.6960 - Mixing of explosive material.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 2010-07-01 2010-07-01 false Mixing of explosive material. 57.6960 Section...Requirements-Underground Only § 57.6960 Mixing of explosive material. (a) The mixing of ingredients to produce explosive...

  11. 30 CFR 56.6205 - Conveying explosives by hand.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Transportation § 56.6205 Conveying explosives by hand. Closed, nonconductive containers shall be used to carry explosives and detonators to and from blast sites. Separate containers shall be...

  12. 30 CFR 57.6205 - Conveying explosives by hand.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...MINES Explosives Transportation-Surface and Underground § 57.6205 Conveying explosives by hand. Closed, nonconductive containers shall be used to carry explosives and detonators to and from blast sites. Separate containers shall be...

  13. 43 CFR 423.30 - Weapons, firearms, explosives, and fireworks.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Weapons, firearms, explosives, and fireworks. 423.30 Section 423.30 Public...Weapons, firearms, explosives, and fireworks. (a) You may possess firearms...must not use or possess explosives, or fireworks or pyrotechnics of any type,...

  14. 43 CFR 423.30 - Weapons, firearms, explosives, and fireworks.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Weapons, firearms, explosives, and fireworks. 423.30 Section 423.30 Public...Weapons, firearms, explosives, and fireworks. (a) You may possess firearms...must not use or possess explosives, or fireworks or pyrotechnics of any type,...

  15. 43 CFR 423.30 - Weapons, firearms, explosives, and fireworks.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Weapons, firearms, explosives, and fireworks. 423.30 Section 423.30 Public...Weapons, firearms, explosives, and fireworks. (a) You may possess firearms...must not use or possess explosives, or fireworks or pyrotechnics of any type,...

  16. 43 CFR 423.30 - Weapons, firearms, explosives, and fireworks.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Weapons, firearms, explosives, and fireworks. 423.30 Section 423.30 Public...Weapons, firearms, explosives, and fireworks. (a) You may possess firearms...must not use or possess explosives, or fireworks or pyrotechnics of any type,...

  17. Biodegradation and biotransformation of explosives.

    PubMed

    Rylott, Elizabeth L; Lorenz, Astrid; Bruce, Neil C

    2011-06-01

    Explosives now contaminate millions of hectares of land in the US alone, with global levels of contamination difficult to fully assess. Understanding the biology behind the metabolism of these toxic compounds by microorganisms and plants is imperative for managing these pollutants in the environment. Towards this aim, recent studies have identified, and are now characterizing, plant genes involved in 2,4,6-trinitrotoluene detoxification and the biochemical pathways of nitramine degradation in microorganisms. A key scientific goal continues to be identification of enzymes capable of degrading 2,4,6-trinitrotoluene and this still remains elusive, although recent reports give insights into the origin of nitrite released during biotransformation of this major contaminant. Promising phytoremediation research using transgenic model plant systems has now been transferred to poplar, a species with field applicability. PMID:21094036

  18. Explosion safety in industrial electrostatics

    NASA Astrophysics Data System (ADS)

    Szabó, S. V.; Kiss, I.; Berta, I.

    2011-01-01

    Complicated industrial systems are often endangered by electrostatic hazards, both from atmospheric (lightning phenomenon, primary and secondary lightning protection) and industrial (technological problems caused by static charging and fire and explosion hazards.) According to the classical approach protective methods have to be used in order to remove electrostatic charging and to avoid damages, however no attempt to compute the risk before and after applying the protective method is made, relying instead on well-educated and practiced expertise. The Budapest School of Electrostatics - in close cooperation with industrial partners - develops new suitable solutions for probability based decision support (Static Control Up-to-date Technology, SCOUT) using soft computing methods. This new approach can be used to assess and audit existing systems and - using the predictive power of the models - to design and plan activities in industrial electrostatics.

  19. ARTSEDGE: Art of the Explosion

    NSDL National Science Digital Library

    If you missed the fireworks on the 4th of July this summer, this website from Washington D.C.'s Kennedy Center is for you. Art of the Explosion is a record of Chinese artist Cai Guo-Qiang's 2005 pyrotechnic work, The Tornado, that was created to launch Kennedy Center's Festival of China. On the site, visitors will find back-stage video, interviews, design sketches, animations, and other documentation that trace Cai's piece from conception to ignition. Intended for high school students, but perfect for all ages, the site also includes a create your own fireworks function, where you can arrange clips of different fireworks like rings, chrysanthemum, or Roman candle, on a timeline and watch them go off.

  20. Educational Resources: The Urban Explosion

    NSDL National Science Digital Library

    These materials are designed to accompany the television program 'Journey to Planet Earth: Urban Explosion'. As the 21st century dawns, the question is how to balance economic growth with the health of Earth's large metropolitan cities. How do these cities shelter and sustain their residents without destroying the delicate balance of the environment? The four mega-cities (cities with populations of over ten million people) profiled in the video segments are Mexico City, Shanghai, Istanbul, and New York City. Through the segments and the activities found at the end of this lesson, students will learn more about the problems facing the world's mega-cities, possible solutions to those problems, and the need for urban planning.

  1. Time-domain terahertz spectroscopy and applications on drugs and explosives

    NASA Astrophysics Data System (ADS)

    Fan, W. H.; Zhao, W.; Cheng, G. H.; Burnett, A. D.; Upadhya, P. C.; Cunningham, J. E.; Linfield, E. H.; Davies, A. G.

    2008-03-01

    Many materials of interest to the forensic and security services, such as explosives, drugs and biological agents, exhibit characteristic spectral features in the terahertz (THz) frequency range. These spectral features originate from inter-molecular interactions, involving collective motions of molecules. Broadband THz time-domain spectroscopy (THz-TDS) system have been used to analyze a number of drugs-of-abuse and explosives that are of interest to the forensic and security services. These samples ranged from crystalline powders, pressed into pellets, to thin sheets of plastic explosives, and all being measured in transmission geometry in the frequency range 0.1 - 8 THz. To well understand the nature of the observed spectral features and the effects of thermal broadening on these far-infrared signatures, temperature-dependent THz-TDS measurements have also been performed at temperatures as low as 4 K, especially for two types of cocaine. Well-resolved low-frequency absorption peaks were observed in the frequency range 0.1 - 3 THz with high resolution. Some of absorption peaks were found clearly to become more intense and shift to higher frequencies as the temperature was reduced. The results confirm that the low-frequency collective modes are highly sensitive to the structural and spatial arrangement of molecules. Furthermore, a number of common postal packaging materials made from paper, cardboard, even several types of plastic, have been tested with drug sample to assess the ability of THz-TDS in a hostile detection environment.

  2. Potential for detection of explosive and biological hazards with electronic terahertz systems.

    PubMed

    Choi, Min Ki; Bettermann, Alan; van der Weide, D W

    2004-02-15

    The terahertz (THz) regime (0.1-10 THz) is rich with emerging possibilities in sensing, imaging and communications, with unique applications to screening for weapons, explosives and biohazards, imaging of concealed objects, water content and skin. Here we present initial surveys to evaluate the possibility of sensing plastic explosives and bacterial spores using field-deployable electronic THz techniques based on short-pulse generation and coherent detection using nonlinear transmission lines and diode sampling bridges. We also review the barriers and approaches to achieving greater sensing-at-a-distance (stand-off) capabilities for THz sensing systems. We have made several reflection measurements of metallic and non-metallic targets in our laboratory, and have observed high contrast relative to reflection from skin. In particular, we have taken small quantities of energetic materials such as plastic explosives and a variety of Bacillus spores, and measured them in transmission and in reflection using a broadband pulsed electronic THz reflectometer. The pattern of reflection versus frequency gives rise to signatures that are remarkably specific to the composition of the target, even though the target's morphology and position is varied. Although more work needs to be done to reduce the effects of standing waves through time-gating or attenuators, the possibility of mapping out this contrast for imaging and detection is very attractive. PMID:15306524

  3. Method for fabricating non-detonable explosive simulants

    DOEpatents

    Simpson, Randall L. (Livermore, CA); Pruneda, Cesar O. (Livermore, CA)

    1995-01-01

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

  4. Method for fabricating non-detonable explosive simulants

    DOEpatents

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

    1995-05-09

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

  5. Chemical analysis kit for the presence of explosives

    DOEpatents

    Eckels, Joel Del (Livermore, CA); Nunes; Peter J. (Danville, CA); Alcaraz, Armando (Livermore, CA); Whipple, Richard E. (Livermore, CA)

    2011-05-10

    A tester for testing for explosives associated with a test location comprising a first explosives detecting reagent; a first reagent holder, the first reagent holder containing the first explosives detecting reagent; a second explosives detecting reagent; a second reagent holder, the second reagent holder containing the second explosives detecting reagent; a sample collection unit for exposure to the test location, exposure to the first explosives detecting reagent, and exposure to the second explosives detecting reagent; and a body unit containing a heater for heating the sample collection unit for testing the test location for the explosives.

  6. American Society of Plastic Surgeons

    MedlinePLUS

    ... Male Specific Gynecomastia Surgery Hair Replacement Men and Plastic Surgery Minimally Invasive Botulinum Toxin Chemical Peel Dermabrasion ... Homework Before and After Photo Gallery Dangers of Plastic Surgery Tourism Video Gallery Patient and Consumer Information ...

  7. The mechanism of instability and localized reaction in the explosively driven collapse of thick walled Ni-Al laminate cylinders

    NASA Astrophysics Data System (ADS)

    Chiu, P. H.; Olney, K. L.; Higgins, A.; Serge, M.; Benson, D. J.; Nesterenko, V. F.

    2013-06-01

    Thick-walled cylinders constructed from alternating concentric layers of Ni and Al foils were explosively collapsed. The prevalent mode of the high strain, high strain rate plastic deformation was the cooperative buckling of the foils originating in the interior layers. This phenomenon was reproduced in numerical simulations. Its mechanism is qualitatively different than that of shear localization seen in all previously investigated homogeneous solid and granular materials and from the independent buckling of single thin-walled cylinders. Localized chemical reactions were observed in the apex areas of the Ni foils, consistent with the localization of temperature due to high strain plastic deformation.

  8. 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…

  9. Music and brain plasticity

    Microsoft Academic Search

    BARBRO B. JOHANSSON

    2006-01-01

    Complex and widespread activation in many brain areas is seen while performing, listening or mentally imaging music, activity that varies with training, previous exposure, personal preference, emotional involvement and many other factors. Playing a musical instrument demands extensive motor and cognitive abilities, and early musical learning results in plastic reorganization of the developing brain one example being the increased cortical

  10. Preserving in Plastic.

    ERIC Educational Resources Information Center

    Wahla, James

    1985-01-01

    Outlines steps for casting insects in permanent molds prepared from commercially available liquid plastic. Also describes dry mountings in glass, acrylic, and petri dishes. The rationale for specimen use, hints for producing quality results, purchasing information, and safety precautions are considered. (DH)

  11. History of Reinforced Plastics

    Microsoft Academic Search

    John V. Milewski; Dominick V. Rosato

    1981-01-01

    This history of reinforced plastics is told by combining the individual histories of each reinforcement and the way in which they added to and changed the direction and rate of growth of the industry. The early history is based on all resins, fillers, and fibers found in nature. Then came the Baekeland revolution with the first synthetic resin which lasted

  12. Fused Plastic Wallet

    NSDL National Science Digital Library

    2014-09-12

    In this up-cycling activity, learners recycle plastic bags and repurpose them into useful wallets. Learners cut and iron grocery bags into new shapes and designs so that they can be reused as wallets. Use this activity to introduce learners to polymers, biodegradable materials, and up-cycling.

  13. Share This: Plastic Day

    E-print Network

    Cakoni, Fioralba

    of Delaware's Earth Week activities surrounding the observance of the 42nd Earth Day on April 22. DENINShare This: Upcoming Events April 18 Plastic Day: Book Discussion & Film April 28 Ag Day The DENIN to strengthen our efforts to understand, predict, and adjust to Earth's changing climate. One mild winter does

  14. Transport of explosives I: TNT in soil and its equilibrium vapor

    NASA Astrophysics Data System (ADS)

    Baez, Bibiana; Correa, Sandra N.; Hernandez-Rivera, Samuel P.; de Jesus, Maritza; Castro, Miguel E.; Mina, Nairmen; Briano, Julio G.

    2004-09-01

    Landmine detection is an important task for military operations and for humanitarian demining. Conventional methods for landmine detection involve measurements of physical properties. Several of these methods fail on the detection of modern mines with plastic enclosures. Methods based on the detection signature explosives chemicals such as TNT and DNT are specific to landmines and explosive devices. However, such methods involve the measurements of the vapor trace, which can be deceiving of the actual mine location because of the complex transport phenomena that occur in the soil neighboring the buried landmine. We report on the results of the study of the explosives subject to similar environmental conditions as the actual mines. Soil samples containing TNT were used to study the effects of aging, temperature and moisture under controlled conditions. The soil used in the investigation was Ottawa sand. A JEOL GCMate II gas chromatograph +/- mass spectrometer coupled to a Tunable Electron Energy Monochromator (TEEM-GC/MS) was used to develop the method of analysis of explosives under enhanced detection conditions. Simultaneously, a GC with micro cell 63Ni, Electron Capture Detector (?ECD) was used for analysis of TNT in sand. Both techniques were coupled with Solid-Phase Micro Extraction (SPME) methodology to collect TNT doped sand samples. The experiments were done in both, headspace and immersion modes of SPME for sampling of explosives. In the headspace experiments it was possible to detect appreciable TNT vapors as early as 1 hour after of preparing the samples, even at room temperature (20 °C). In the immersion experiments, I-SPME technique allowed for the detection of concentrations as low as 0.010 mg of explosive per kilogram of soil.

  15. What Is a Pediatric Plastic Surgeon?

    MedlinePLUS

    ... Surgeon? Family Life Listen What is a Pediatric Plastic Surgeon? Article Body If your child needs surgery ... plastic surgeon. What Kind of Training Do Pediatric Plastic Surgeons Have? Pediatric plastic surgeons are medical doctors ...

  16. The Plastic Ocean Michael Gonsior

    E-print Network

    Boynton, Walter R.

    The Plastic Ocean Michael Gonsior Bonnie Monteleone, William Cooper, Jennifer O'Keefe, Pamela into small particles that wreck havoc with marine life #12;Can you tell which is the hydrozoan and which is the plastic cheese wrap? Unfortunately, marine creatures mistake plastics in the ocean for food #12

  17. Characteristics of Plasticized PVC Biodegradation

    Microsoft Academic Search

    K. Z. Gumargalieva; G. E. Zaikov; S. A. Semenov; O. A. Zhdanova

    1998-01-01

    The influence of microscopic fungus Aspergillus niger on the diffusion desorption of the plasticizer (dialkylphthalate) in PVC were studied. It was shown that desorption of di-alkylphthalate is accelerated by bio-overgrowth of plasticized PVC samples. Thus, the transfer of the plasticizer is controlled by its diffusion.

  18. An Overview of Plastics Recycling

    Microsoft Academic Search

    Jack Milgrom

    1982-01-01

    In 1980, plastic in the United States has overtaken steel on a volume basis as the dominant material. Though recycling of iron and steel goes back to the early years of United States history, plastics recycling is in its infancy. Today, plastics recycling is an urgent necessity as petrochemical raw materials, energy, and disposal become more costly.

  19. 2013 PLASTIC SURGERY VISITING PROFESSOR

    E-print Network

    Shoubridge, Eric

    2013 PLASTIC SURGERY VISITING PROFESSOR Dr. Mutaz B. Habal June 6, 2013 McGill University Division of Plastic Surgery 2013 PLASTIC SURGERY VISITING PROFESSOR Special thanks to our sponsors: Representative Surgery MUHC McGill University Campagne Les meilleurs soins pour la vie The Best Care for Life Campaign

  20. Explosive-array performance measurement using TDR

    SciTech Connect

    McKown, T.O. [Los Alamos National Lab., NM (United States); Eilers, D.D. [Raytheon Services Nevada, Las Vegas, NV (United States)

    1994-04-01

    The system known as CORRTEX was developed for determining the yield of a nuclear explosion by measuring the position of its shock front as a function of time. The CORRTEX system is a compact, fast sampling TDR based system where only a length of 50 ohm coaxial cable (the sensing element) is expended in the detonation. In 1979, the application of the CORRTEX system to measure the explosive bum of columns of conventional explosive in one or more drill holes was demonstrated. Subsequently, the CORRTEX system was used to diagnose complicated multiple hole high explosive oilshale, rock quarry and strip mining shots. The diagnostic timing and explosive characterization data from large array or large mass detonations provide a basis for performance improvement and comparison with calculational models. A summary of the CORRTEX capabilities and analysis techniques will be presented. Experiment designs and data from large array detonations will be presented, results from a confined large mass ANFO explosion will be summarized and other possible non-explosive applications may be presented.

  1. Concussive brain injury from explosive blast

    PubMed Central

    de Lanerolle, Nihal C; Hamid, Hamada; Kulas, Joseph; Pan, Jullie W; Czlapinski, Rebecca; Rinaldi, Anthony; Ling, Geoffrey; Bandak, Faris A; Hetherington, Hoby P

    2014-01-01

    Objective Explosive blast mild traumatic brain injury (mTBI) is associated with a variety of symptoms including memory impairment and posttraumatic stress disorder (PTSD). Explosive shock waves can cause hippocampal injury in a large animal model. We recently reported a method for detecting brain injury in soldiers with explosive blast mTBI using magnetic resonance spectroscopic imaging (MRSI). This method is applied in the study of veterans exposed to blast. Methods The hippocampus of 25 veterans with explosive blast mTBI, 20 controls, and 12 subjects with PTSD but without exposure to explosive blast were studied using MRSI at 7 Tesla. Psychiatric and cognitive assessments were administered to characterize the neuropsychiatric deficits and compare with findings from MRSI. Results Significant reductions in the ratio of N-acetyl aspartate to choline (NAA/Ch) and N-acetyl aspartate to creatine (NAA/Cr) (P < 0.05) were found in the anterior portions of the hippocampus with explosive blast mTBI in comparison to control subjects and were more pronounced in the right hippocampus, which was 15% smaller in volume (P < 0.05). Decreased NAA/Ch and NAA/Cr were not influenced by comorbidities – PTSD, depression, or anxiety. Subjects with PTSD without blast had lesser injury, which tended to be in the posterior hippocampus. Explosive blast mTBI subjects had a reduction in visual memory compared to PTSD without blast. Interpretation The region of the hippocampus injured differentiates explosive blast mTBI from PTSD. MRSI is quite sensitive in detecting and localizing regions of neuronal injury from explosive blast associated with memory impairment. PMID:25493283

  2. A QSPR for the plasticization efficiency of polyvinylchloride plasticizers.

    PubMed

    Chandola, Mridula; Marathe, Sujata

    2008-01-01

    A simple quantitative structure property relationship (QSPR) for correlating the plasticization efficiency of 25 polyvinylchloride (PVC) plasticizers was obtained using molecular modeling. The plasticizers studied were-aromatic esters (phthalate, terephthalate, benzoate, trimellitate), aliphatic esters (adipate, sebacate, azelate), citrates and a phosphate. The low temperature flex point, Tf, of plasticized polyvinylchloride resins was considered as an indicator of plasticization efficiency. Initially, we attempted to predict plasticization efficiency of PVC plasticizers from physical and structural descriptors derived from the plasticizer molecule alone. However, the correlation of these descriptors with Tf was not very good with R=0.78 and r2=0.613. This implied that the selected descriptors were unable to predict all the interactions between PVC and plasticizer. Hence, to account for these interactions, a model containing two polyvinylchloride (PVC) chain segments along with a plasticizer molecule in a simulation box was constructed, using molecular mechanics. A good QSPR equation correlating physical and structural descriptors derived from the model to Tf of the plasticized resins was obtained with R=0.954 and r2=0.909. PMID:17566774

  3. Modelling and simulation of explosions in soil interacting with deformable structures

    NASA Astrophysics Data System (ADS)

    Zakrisson, Björn; Häggblad, Hans-Áke; Jonsén, Pär

    2012-12-01

    A detonating explosive interacting with a deformable structure is a highly transient and non-linear event. In field blast trials of military vehicles, a standard procedure is often followed in order to reduce the uncertainties and increase the quality of the test. If the explosive is buried in the ground, the state of the soil must meet specific demands. In the present work, laboratory experiments have been performed to characterize the behaviour of a soil material. Soil may be considered a three-phase medium, consisting of solid grains, water and air. Variations between the amounts of these phases affect the mechanical properties of the soil. The experimental outcome has formed input data to represent the soil behaviour included in a three-phase elastic-plastic cap model. This unified constitutive model for soil has been used for numerical simulations representing field blast trials, where the explosive load is interacting with a deformable structure. The blast trials included explosive buried at different depths in wet or dry sand. A dependence of the soil initial conditions can be shown, both in the past field trials along with the numerical simulations. Even though some deviations exist, the simulations showed in general acceptable agreement with the experimental results.

  4. Level II Milestone Review of LLNL Program on Grain-Scale Dynamics in Explosives

    SciTech Connect

    Nicol, M F; Benson, D J; Yip, S

    2003-01-14

    This document describes an evaluation of the Level II Milestone achievements of the LLNL program on Grain-Scale Dynamics in Explosives on January 14, 2003. ''The Grain-Scale Dynamics in Explosives Program'' is a mixture of advanced computational methodology and physico-chemical theory applied to understanding deflagration and detonation of plastic-bonded explosives from the nano to the macro scales. At many points, the modeling is tied directly to experiments within the precisions of both. Advances are needed in the experimental, theoretical, and computational aspects of detonations. Work reported in this review represents significant, cross-pollinating advances in each area. The team successfully carried out ALE-3D simulations of deflagration in PBX with grain scale effects. (Milestone requirements 1 and 2), interpreted experimental data on flame speed vs. pressure and sensitivity to global kinetics in terms of ALE-3D simulations (Milestone requirement 3), and used the results of these simulations to develop a continuum reactive flow model that captures some of these effects (Milestone requirement 4). By comparing experiments and detonation velocities in small diameter, unconfined explosives, they found non-idealities that remain at intermediate diameters (ca. 1.5 mm) that require further analysis. In all of these areas, the project team has met, indeed exceeded, their Level II Milestone goals.

  5. Simplified Explosive Joining of Tubes to Fittings

    NASA Technical Reports Server (NTRS)

    Bement, L. J.; Bailey, J. W.; Perry, R.; Finch, M. S.

    1987-01-01

    Technique simplifies tube-to-fitting joining, as compared to fusion welding, and provides improvement on standard procedures used to join tubes explosively to tube fittings. Special tool inserted into tube to be joined. Tool allows strip of ribbon explosive to be placed right at joint. Ribbon explosive and mild detonating fuse allows use of smaller charge. Assembled tool storable, and process amenable to automation. Assembly of components, insertion of tool into weld site, and joining operation mechanized without human contact. Used to assemble components in nuclear reactors or in other environments hostile to humans.

  6. Explosive propulsion applications. [to future unmanned missions

    NASA Technical Reports Server (NTRS)

    Nakamura, Y.; Varsi, G.; Back, L. H.

    1974-01-01

    The feasibility and application of an explosive propulsion concept capable of supporting future unmanned missions in the post-1980 era were examined and recommendations made for advanced technology development tasks. The Venus large lander mission was selected as the first in which the explosive propulsion concept can find application. A conceptual design was generated and its performance, weight, costs, and interaction effects determined. Comparisons were made with conventional propulsion alternatives. The feasibility of the explosive propulsion system was verified for planetology experiments within the dense atmosphere of Venus as well as the outer planets. Additionally, it was determined that the Venus large lander mission could be augmented ballistically with a significant delivery margin.

  7. Instrumentation for trace detection of high explosives

    NASA Astrophysics Data System (ADS)

    Moore, D. S.

    2004-08-01

    There is at present an urgent need for trace detection of high explosives, with applications to screening of people, packages, luggage, and vehicles. A great concern, because of recent terrorist activities, is for the development of methods that might allow detection and identification of explosives at a stand off distance. Nearly every analytical chemical method has been or is being applied to this problem. This review outlines the properties of explosives that might be utilized in detection schemes, discusses sampling issues, presents recent method developments with particular attention to detection limits, speed of analysis, and portability, and looks towards future developments.

  8. Simulation of collisional fragmentation with explosives

    NASA Technical Reports Server (NTRS)

    Housen, Kevin

    1993-01-01

    For practical reasons, experimental studies of collisional fragmentation must at times rely on explosives to fragment a target body. For example, Housen et al., described experiments in which spheres were fragmented in a pressurized atmosphere. Explosives were used because impacts could not be performed in the pressure chamber. Explosives can also be used to study targets much larger than those which can be disrupted by conventional light-gas guns, thereby allowing size- and rate-effects to be investigated. The purpose of this study is to determine the charge burial depth required to simulate various aspects of collisions.

  9. Explosion Shear Wave Generation and Scattering

    NASA Astrophysics Data System (ADS)

    Baker, G. E.; Stevens, J. L.; Xu, H.

    2004-12-01

    We use observations of explosion-generated Lg together with three separate types of numerical models to determine how underground nuclear explosions generate shear wave phases. This question is fundamental to how Lg phases are interpreted for use in explosion yield estimation and earthquake/explosion discrimination. A simple point explosion in a uniform medium generates no shear waves, so the Lg phase is generated entirely by non-spherical components of the source and conversions through reflections and scattering. Our results indicate that the most important sources of high frequency explosion shear waves are P to S conversions at the free surface and S waves generated directly by a realistic distributed explosion source including nonlinear effects due to the free surface and gravity. In addition, Rg scattering may contribute to lower frequency Lg. Near source S is observed on both radial and tangential component records from a diverse set of explosion data. The data sets include 1) Degelen Mountain explosions recorded at distances less than 100 km and corresponding recordings at Borovoye (BOR) at 650 km; 2) recordings from Russian deep seismic sounding experiments; 3) Nevada Test Site (NTS) explosion sources including the Nonproliferation Experiment (NPE) and nuclear tests covering a range of source depths and media properties. We model the overburied NPE, and underburied and overburied Degelen explosions, using point sources and two-dimensional nonlinear finite difference calculations to quantify the source effects. We use energy conservation to determine an upper bound on Rg to Lg scattering. Results indicate that Rg to Lg scattering may be important at frequencies less than 1 Hz, and in Lg coda, but is less than Lg generated directly by the explosion at higher frequencies. We use 2D and 3D finite difference calculations, using the known topography and velocity structure at Degelen Mt. and lateral heterogeneities within the crust, to estimate the effect of surface and crustal scattering on Lg. Results indicate that topographic scattering can significantly disrupt the surface pS scattered phase, so more shear wave energy is trapped in the crust. The topography also appears to be the most significant scatterer of Rg, and has a profound effect on its dispersion.

  10. Cosmological explosions from cold dark matter perturbations

    NASA Technical Reports Server (NTRS)

    Scherrer, Robert J.

    1992-01-01

    The cosmological-explosion model is examined for a universe dominated by cold dark matter in which explosion seeds are produced from the growth of initial density perturbations of a given form. Fragmentation of the exploding shells is dominated by the dark-matter potential wells rather than the self-gravity of the shells, and particular conditions are required for the explosions to bootstrap up to very large scales. The final distribution of dark matter is strongly correlated with the baryons on small scales, but uncorrelated on large scales.

  11. Experimental transient and permanent deformation studies of steel-sphere-impacted or explosively-impulsed aluminum panels

    NASA Technical Reports Server (NTRS)

    Witmer, E. A.; Merlis, F.; Rodal, J. J. A.; Stagliano, T. R.

    1977-01-01

    The sheet explosive loading technique (SELT) was employed to obtain elastic-plastic, large deflection 3-d transient and/or permanent strain data on simple well defined structural specimens and materials: initially-flat 6061-T651 aluminum panels with all four sides ideally clamped via integral construction. The SELT loading technique was chosen since it is both convenient and provides "forcing function information" of small uncertainty. These data will be useful for evaluating pertinent 3-d structural response prediction methods.

  12. Imperatives for the Plastic Industry in India

    Microsoft Academic Search

    Mukesh Ambani

    2003-01-01

    A plastic consumer will no longer use plastic materials. He will demand systems at a holistic level. Conventional thermoplastics will give way to biocompatible systems that incorporate recycling processes and biopolymers. Engineering plastics will give primacy to performance plastics based on composites of plastics with metals and ceramics. Plastics for drip irrigation, mulching, low tunnels and so on will pave

  13. Electron-microscopic examination of the transition zone of aluminum-tantalum bimetallic joints (explosion welding)

    NASA Astrophysics Data System (ADS)

    Volkova, A. Yu.; Greenberg, B. A.; Ivanov, M. A.; Elkina, O. A.; Inozemtsev, A. V.; Plotnikov, A. V.; Patselov, A. M.; Kozhevnikov, V. E.

    2014-04-01

    A study of the structure of an aluminum-tantalum joint and a comparison of this structure with the structures of iron-silver and copper-tantalum joints have revealed the following processes of the interpenetration of the materials that occur during explosion welding: the formation of protrusions, the injection of particles of one material into the other, and the formation of zones of local melting. Regardless of the mutual solubility of the metals being welded, two types of fragmentation occur, i.e., (1) a granulating fragmentation (GF), which includes the formation, explosion-governed (EG) dispersion, and partial consolidation of particles, and (2) the fragmentation that is usually observed during severe plastic deformation. It is important that this traditional fragmentation is not accompanied by the formation and EG dispersion of particles. This feature allows one to easily distinguish these types of fragmentation (traditional and GF fragmentation).

  14. Supernova neutrinos and explosive nucleosynthesis

    SciTech Connect

    Kajino, T. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan and Department of Astronomy, Graduate School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan); Aoki, W. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Cheoun, M.-K. [Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of); Hayakawa, T. [Japan Atomic Energy Agency, Shirakara-Shirane 2-4, Tokai-mura, Ibaraki 319-1195 (Japan); Hidaka, J.; Hirai, Y.; Shibagaki, S. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Mathews, G. J. [Center for Astrophysics, Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Nakamura, K. [Faculty of Science and Engineering, Waseda University, Ohkubo 3-4-1, Shinjuku, Tokyo 169-8555 (Japan); Suzuki, T. [Department of Physics, College of Humanities and Sciences, Nihon University, Sakurajosui 3-25-40, Setagaya-ku, Tokyo 156-8550 (Japan)

    2014-05-09

    Core-collapse supernovae eject huge amount of flux of energetic neutrinos. We studied the explosive nucleosyn-thesis in supernovae and found that several isotopes {sup 7}Li, {sup 11}B, {sup 92}Nb, {sup 138}La and {sup 180}Ta as well as r-process nuclei are affected by the neutrino interactions. The abundance of these isotopes therefore depends strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. We discuss first how to determine the neutrino temperatures in order to explain the observed solar system abundances of these isotopes, combined with Galactic chemical evolution of the light nuclei and the heavy r-process elements. We then study the effects of neutrino oscillation on their abundances, and propose a novel method to determine the still unknown neutrino oscillation parameters, mass hierarchy and ?{sub 13}, simultaneously. There is recent evidence that SiC X grains from the Murchison meteorite may contain supernova-produced light elements {sup 11}B and {sup 7}Li encapsulated in the presolar grains. Combining the recent experimental constraints on ?{sub 13}, we show that our method sug-gests at a marginal preference for an inverted neutrino mass hierarchy. Finally, we discuss supernova relic neutrinos that may indicate the softness of the equation of state (EoS) of nuclear matter as well as adiabatic conditions of the neutrino oscillation.

  15. Explosive and pyrotechnic aging demonstration

    NASA Technical Reports Server (NTRS)

    Rouch, L. L., Jr.; Maycock, J. N.

    1976-01-01

    The survivability was experimentally verified of fine selected explosive and pyrotechnic propellant materials when subjected to sterilization, and prolonged exposure to space environments. This verification included thermal characterization, sterilization heat cycling, sublimation measurements, isothermal decomposition measurements, and accelerated aging at a preselected elevated temperature. Temperatures chosen for sublimation and isothermal decomposition measurements were those in which the decomposition processess occurring would be the same as those taking place in real-time aging. The elevated temperature selected (84 C) for accelerated aging was based upon the parameters calculated from the kinetic data obtained in the isothermal measurement tests and was such that one month of accelerated aging in the laboratory approximated one year of real-time aging at 66 C. Results indicate that HNS-IIA, pure PbN6, KDNBF, and Zr/KC10 are capable of withstanding sterilization. The accelerated aging tests indicated that unsterilized HNS-IIA and Zr/KC104 can withstand the 10 year, elevated temperature exposure, pure PbN6 and KDNBF exhibit small weight losses (less than 2 percent) and B/KC104 exhibits significant changes in its thermal characteristics. Accelerated aging tests after sterilization indicated that only HNS-IIA exhibited high stability.

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  17. Rotationally resolved infrared spectra of the explosive bouquet compounds associated with C-4 explosives

    NASA Astrophysics Data System (ADS)

    Clasp, Trocia N.; Johnson, Tiffani; Sullivan, Michael N.; Reeve, Scott W.

    2011-05-01

    The explosive material known as Composition C4, or simply C4, is an RDX based military grade explosive. RDX itself possesses a negligible vapor pressure at room temperature suggesting it is not a good target for conventional instruments designed to detect vapor phase chemical compounds. Recent research with canines has indicated that a better approach for detecting explosive vapors such as C4 is to focus on a characteristic mixture of impurities associated with the material. These characteristic mixtures of impurity vapors are referred to by canine researchers as the explosive bouquet and are fairly unique to the specific energetic material. In this paper, we will examine and report rotationally resolved infrared spectral signatures for the known compounds comprising the explosive bouquet for C4 based explosives including isobutylene, 2-ethyl-1-hexanol and cyclohexanone.

  18. 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

  19. Testing of reinforced plastics

    NASA Astrophysics Data System (ADS)

    Epstein, G.

    Tests of reinforced plastics are presented to determine the suitability of the materials, processes, and design for a proposed application. A listing of the types of tests is given including arc resistance tests, bonding strength tests, and light diffusion tests. Specimen configuration, standardized temperature and humidity conditions, and directional properties are examples of considerations which aid in obtaining valid results. Tests of the raw materials to be used in a reinforced plastic construction are presented, as this component serves as a quality control. Standards and specifications for testing methods used for various types of reinforcement materials (glass fiber, asbestos, quartz, etc.) are given. Basic properties of moldings and laminates are determined (physical, mechanical, electrical, etc.), and other tests include flexural strength at elevated temperatures, flammability, and outgassing.

  20. Breathing: rhythmicity, plasticity, chemosensitivity.

    PubMed

    Feldman, Jack L; Mitchell, Gordon S; Nattie, Eugene E

    2003-01-01

    Breathing is a vital behavior that is particularly amenable to experimental investigation. We review recent progress on three problems of broad interest. (i) Where and how is respiratory rhythm generated? The preBötzinger Complex is a critical site, whereas pacemaker neurons may not be essential. The possibility that coupled oscillators are involved is considered. (ii) What are the mechanisms that underlie the plasticity necessary for adaptive changes in breathing? Serotonin-dependent long-term facilitation following intermittent hypoxia is an important example of such plasticity, and a model that can account for this adaptive behavior is discussed. (iii) Where and how are the regulated variables CO2 and pH sensed? These sensors are essential if breathing is to be appropriate for metabolism. Neurons with appropriate chemosensitivity are spread throughout the brainstem; their individual properties and collective role are just beginning to be understood. PMID:12598679

  1. Paper or Plastic?

    NSDL National Science Digital Library

    2008-09-11

    This site, part of Exploring Earth Investigation by McDougal Littell and TERC, examines the environmental impacts of both paper and plastic bags and answers the old question "paper or plastic?" These investigations "were designed to build students' knowledge of Earth Science conceptsâ?¦and to raise student awareness of Earth as a system of interconnected components and processes." Here, visitors can find lessons on Earth's systems and the impacts of each decision, as well as how to research and make your argument once you have decided your answer. Many sections have illustrative images and interactive features, which help students, understand the topics presented, and the final section provides links to resources that will help students investigate this subject further. This is an excellent site for any Earth Science classroom as an introductory lecture or as an out-of-class exploration for students.

  2. Simulating thermal explosion of cyclotrimethylenetrinitramine-based explosives: Model comparison with experiment

    Microsoft Academic Search

    Jack J. Yoh; Matthew A. McClelland; Jon L. Maienschein; Jeffrey F. Wardell; Craig M. Tarver

    2005-01-01

    We compare two-dimensional model results with measurements for the thermal, chemical, and mechanical behavior in a thermal explosion experiment. Confined high explosives (HEs) are heated at a rate of 1 °C\\/h until an explosion is observed. The heating, ignition, and deflagration phases are modeled using an Arbitrarily Lagrangian-Eulerian code (ALE3D) that can handle a wide range of time scales that

  3. Simulating thermal explosion of octahydrotetranitrotetrazine-based explosives: Model comparison with experiment

    Microsoft Academic Search

    Jack J. Yoh; Matthew A. McClelland; Jon L. Maienschein; Albert L. Nichols; Craig M. Tarver

    2006-01-01

    A model comparison with measurements for the thermal, chemical, and mechanical behaviors in a thermal explosion experiment is presented. Confined high explosives (HEs) are heated at a rate of 1 °C?h until an explosion is observed. The heating, ignition, and deflagration phases are modeled using an arbitrarily Lagrangian-Eulerian (ALE3D) code that can handle a wide range of time scales that

  4. Simulating thermal explosion of cyclotrimethylenetrinitramine-based explosives: Model comparison with experiment

    Microsoft Academic Search

    Jack J. Yoh; Matthew A. McClelland; Jon L. Maienschein; Jeffrey F. Wardell; Craig M. Tarver

    2005-01-01

    We compare two-dimensional model results with measurements for the thermal, chemical, and mechanical behavior in a thermal explosion experiment. Confined high explosives (HEs) are heated at a rate of 1 °C?h until an explosion is observed. The heating, ignition, and deflagration phases are modeled using an Arbitrarily Lagrangian-Eulerian code (ALE3D) that can handle a wide range of time scales that

  5. Simulating thermal explosion of octahydrotetranitrotetrazine-based explosives: Model comparison with experiment

    Microsoft Academic Search

    Jack J. Yoh; Matthew A. McClelland; Jon L. Maienschein; Albert L. Nichols; Craig M. Tarver

    2006-01-01

    A model comparison with measurements for the thermal, chemical, and mechanical behaviors in a thermal explosion experiment is presented. Confined high explosives (HEs) are heated at a rate of 1 °C\\/h until an explosion is observed. The heating, ignition, and deflagration phases are modeled using an arbitrarily Lagrangian-Eulerian (ALE3D) code that can handle a wide range of time scales that

  6. 32 CFR 1903.9 - Explosives.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...ammunition or explosive materials is prohibited on any Agency installation, except as authorized by the Director of the Center for CIA Security. When permitted, the use, possession, storage, and transportation shall be in accordance with applicable...

  7. 30 CFR 7.306 - Explosion tests.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...ignition of each test. Each externally visible flame-arresting path...for discharge of flames for at least two of the tests, including one with...performance. Explosion tests of a motor assembly...1) Discharge of flames. (2)...

  8. 30 CFR 7.306 - Explosion tests.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...ignition of each test. Each externally visible flame-arresting path...for discharge of flames for at least two of the tests, including one with...performance. Explosion tests of a motor assembly...1) Discharge of flames. (2)...

  9. 30 CFR 7.306 - Explosion tests.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...ignition of each test. Each externally visible flame-arresting path...for discharge of flames for at least two of the tests, including one with...performance. Explosion tests of a motor assembly...1) Discharge of flames. (2)...

  10. 30 CFR 7.306 - Explosion tests.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...ignition of each test. Each externally visible flame-arresting path...for discharge of flames for at least two of the tests, including one with...performance. Explosion tests of a motor assembly...1) Discharge of flames. (2)...

  11. Saturn's Hot Plasma Explosions - Duration: 81 seconds.

    NASA Video Gallery

    This animation based on data obtained by NASA's Cassini Spacecraft shows how the "explosions" of hot plasma on the night side (orange and white) periodically inflate Saturn's magnetic field (white ...

  12. Highly explosive nanosilicon-based composite materials

    NASA Astrophysics Data System (ADS)

    Clément, D.; Diener, J.; Gross, E.; Künzner, N.; Timoshenko, V. Yu.; Kovalev, D.

    2005-06-01

    We present a highly explosive binary system based on porous silicon layers with their pores filled with solid oxidizers. The porous layers are produced by a standard electrochemical etching process and exhibit properties that are different from other energetic materials. Its production is completely compatible with the standard silicon technology and full bulk silicon wafers can be processed and therefore a large number of explosive elements can be produced simultaneously. The application-relevant parameters: the efficiency and the long-term stability of various porous silicon/oxidizer systems have been studied in details. Structural properties of porous silicon, its surface termination, the atomic ratio of silicon to oxygen and the chosen oxidizers were optimized to achieve the highest efficiency of the explosive reaction. This explosive system reveals various possible applications in different industrial fields, e.g. as a novel, very fast airbag igniter.

  13. Differential Spectroscopic Imaging of Particulate Explosives Residue

    SciTech Connect

    Bernacki, Bruce E.; Ho, Nicolas

    2008-04-01

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

  14. 32 CFR 1903.9 - Explosives.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...ammunition or explosive materials is prohibited on any Agency installation, except as authorized by the Director of the Center for CIA Security. When permitted, the use, possession, storage, and transportation shall be in accordance with applicable...

  15. 32 CFR 1903.9 - Explosives.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...ammunition or explosive materials is prohibited on any Agency installation, except as authorized by the Director of the Center for CIA Security. When permitted, the use, possession, storage, and transportation shall be in accordance with applicable...

  16. 46 CFR 147.95 - Explosives.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Explosive ships' signals and emergency equipment, including pyrotechnic distress signals and line throwing equipment, must be stowed...watertight containers or wood lined magazine chests. (2) All pyrotechnic distress signals, rockets, and line throwing guns...

  17. 32 CFR 1903.9 - Explosives.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Other Regulations Relating to National Defense CENTRAL INTELLIGENCE AGENCY CONDUCT ON AGENCY INSTALLATIONS § 1903.9 Explosives...and shall also be in accordance with applicable Central Intelligence Agency rules and/or regulations. (b) Using,...

  18. 32 CFR 1903.9 - Explosives.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Other Regulations Relating to National Defense CENTRAL INTELLIGENCE AGENCY CONDUCT ON AGENCY INSTALLATIONS § 1903.9 Explosives...and shall also be in accordance with applicable Central Intelligence Agency rules and/or regulations. (b) Using,...

  19. Corona-discharge-initiated mine explosions

    SciTech Connect

    Sacks, H.K.; Novak, T. [Virginia Polytechnic Institute & State University, Blacksburg, VA (United States). Dept. of Mining & Minerals Engineering

    2005-10-01

    Strong circumstantial evidence suggests that lightning has initiated methane explosions in abandoned and sealed areas of underground coal mines. The Mine Safety and Health Administration (MSHA) investigated several of these occurrences within recent years. The investigated explosions occurred at significant depths, ranging from 700 to 1200 ft. Data from the National Lightning Detection Network indicated a strong correlation between the times and locations of the explosions with those of specific lightning strikes. This paper proposes that corona discharge from a steel borehole casing is the most likely mechanism responsible for these ignitions. A recently investigated mine explosion and fire at a depth greater than 1000 ft was selected for this study. Computer simulations were performed, using data collected at the mine site. CDEGS software from Safe Engineering Services & Technologies, Ltd. and MaxwellSV from Ansoft Corporation were used for the simulations.

  20. Explosives detection by nuclear quadrupole resonance (NQR)

    NASA Astrophysics Data System (ADS)

    Garroway, Allen N.; Buess, Michael L.; Yesinowski, James P.; Miller, Joel B.; Krauss, Ronald A.

    1994-10-01

    Pure nuclear quadrupole resonance (NQR) of 14N nuclei is quite promising as a method for detecting explosives such as RDX and contraband narcotics such as cocaine and heroin in quantities of interest. Pure NQR is conducted without an external applied magnetic field, so potential concerns about damage to magnetically encoded data or exposure of personnel to large magnetic fields are not relevant. Because NQR frequencies of different compounds are quite distinct, we do not encounter false alarms from the NQR signals of other benign materials. We have constructed a laboratory prototype NQR explosives detector which interrogates a volume of 300 liters (10 ft3). This paper presents abbreviated results from a demonstration of the laboratory prototype NQR explosives detector conducted at the Federal Aviation Administration Technical Center in May 1994 on RDX-based explosives.

  1. 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

  2. Neurotrophins and Neuronal Plasticity

    Microsoft Academic Search

    Hans Thoenen

    1995-01-01

    There is increasing evidence that neurotrophins (NTs) are involved in processes of neuronal plasticity besides their well-established actions in regulating the survival, differentiation, and maintenance of functions of specific populations of neurons. Nerve growth factor, brain-derived neurotrophic factor, NT-4\\/5, and corresponding antibodies dramatically modify the development of the visual cortex. Although the neuronal elements involved have not yet been identified,

  3. A viscoplastic model of expanding cylindrical shells subjected to internal explosive detonations

    SciTech Connect

    Martineau, R.L.

    1998-04-01

    Magnetic flux compression generators rely on the expansion of thin ductile shells to generate magnetic fields. These thin shells are filled with high explosives, which when detonated, cause the shell to expand to over 200% strain at strain-rates on the order of 10{sup 4} s{sup {minus}1}. Experimental data indicate the development and growth of multiple plastic instabilities which appear in a quasi-periodic pattern on the surfaces of the shells. These quasi-periodic instabilities are connected by localized zones of intense shear that are oriented approximately 45{degree} from the outward radial direction. The quasi-periodic instabilities continue to develop and eventually become through-cracks, causing the shell to fragment. A viscoplastic constitutive model is formulated to model the high strain-rate expansion and provide insight into the development of plastic instabilities. The formulation of the viscoplastic constitutive model includes the effects of shock heating and damage in the form of microvoid nucleation, growth, and coalescence in the expanding shell. This model uses the Johnson-Cook strength model with the Mie-Grueneisen equation of state and a modified Gurson yield surface. The constitutive model includes the modifications proposed by Tvergaard and the plastic strain controlled nucleation introduced by Neeleman. The constitutive model is implemented as a user material subroutine into ABAQUS/Explicit, which is a commercially available nonlinear explicit dynamic finite element program. A cylindrical shell is modeled using both axisymmetric and plane strain elements. Two experiments were conducted involving plane wave detonated, explosively filled, copper cylinders. Instability, displacement, and velocity data were recorded using a fast framing camera and a Fabry-Perot interferometer. Good agreement is shown between the numerical results and experimental data. An additional explosively bulged cylinder experiment was also performed and a photomicrograph of an instability is shown to provide a qualitative comparison between the experimental observations and the numerical predictions.

  4. Microelectronics plastic molded packaging

    SciTech Connect

    Johnson, D.R. [Ktech Corp., Albuquerque, NM (United States); Palmer, D.W.; Peterson, D.W. [Sandia National Lab., Albuquerque, NM (United States)] [and others

    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.

  5. Plastics eLearning

    NSDL National Science Digital Library

    The Plastics Resources for Educators Program (PREP) has developed a broad range of multimedia instructional resources on synthesis, structure, properties, applications and processing of plastics. The interactive programs and virtual instruments create an exploratory learning environment that allows students to explore complex multivariable problems. This project is to develop a sustainable dissemination effort that includes workshops for faculty and the construction of workbooks and CDROMs that customize the use of various modules to address educational needs of different audiences. Dissemination is done through a commercial publisher, but marketing is done through faculty contacts, industrial partners, a special interest group associated with the Society of Plastics Engineers and presentations at professional meetings. A PREP web site is a communications and distribution hub. Formative and summative evaluation of all components is done by a third party evaluator. The interactive electronic materials provide faculty with new ways of teaching. MERC Online reviewer comments: Innovative simulations allow students to virtually operate equipment. Animations show crow sections of processes. Free, easily downloadable animations, images, and simulations.

  6. Explosive laser light initiation of propellants

    SciTech Connect

    Piltch, M.S.

    1992-12-31

    This invention is comprised of an improved initiator for artillery shell using an explosively generated laser light to uniformly initiate the propellent. A small quantity of a high explosive, when detonated, creates a high pressure and temperature, causing the surrounding noble gas to fluoresce. This fluorescence is directed into a lasing material, which lases, and directs laser light into a cavity in the propellant, uniformly initiating the propellant.

  7. The ENAM Explosive Seismic Source Test

    NASA Astrophysics Data System (ADS)

    Harder, S. H.; Magnani, M. B.

    2013-12-01

    We present the results of the pilot study conducted as part of the eastern North American margin (ENAM) community seismic experiment (CSE) to test an innovative design of land explosive seismic source for crustal-scale seismic surveys. The ENAM CSE is a community based onshore-offshore controlled- and passive-source seismic experiment spanning a 400 km-wide section of the mid-Atlantic East Coast margin around Cape Hatteras. The experiment was designed to address prominent research questions such as the role of the pre-existing lithospheric grain on the structure and evolution of the ENAM margin, the distribution of magmatism, and the along-strike segmentation of the margin. In addition to a broadband OBS deployment, the CSE will acquire multichannel marine seismic data and two major onshore-offshore controlled-source seismic profiles recording both marine sources (airguns) and land explosions. The data acquired as part of the ENAM CSE will be available to the community immediately upon completion of QC procedures required for archiving purposes. The ENAM CSE provides an opportunity to test a radically new and more economical design for land explosive seismic sources used for crustal-scale seismic surveys. Over the years we have incrementally improved the performance and reduced the cost of shooting crustal seismic shots. These improvements have come from better explosives and more efficient configuration of those explosives. These improvements are largely intuitive, using higher velocity explosives and shorter, but larger diameter explosive configurations. However, recently theoretical advances now allow us to model not only these incremental improvements, but to move to more radical shot designs, which further enhance performance and reduce costs. Because some of these designs are so radical, they need experimental verification. To better engineer the shots for the ENAM experiment we are conducting an explosives test in the region of the ENAM CSE. The results of this test will guide engineering for the main ENAM experiment as well as other experiments in the future.

  8. Explosives detection via fast neutron transmission spectroscopy

    NASA Astrophysics Data System (ADS)

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

    2006-10-01

    A review of a five-year project on detection of explosives in luggage is presented. Experimental methods are described. Explosive detection algorithms based on elemental distributions in a 5-dimensional space are also described. Single-blind tests of the method suggest that a false-alarm rate of 4% and a detection rate of 93% are possible. Improvements in the method are suggested. Measurements of neutron total cross sections for chlorine are presented.

  9. Managing traumatic brain injury secondary to explosions

    PubMed Central

    Burgess, Paula; E Sullivent, Ernest; M Sasser, Scott; M Wald, Marlena; Ossmann, Eric; Kapil, Vikas

    2010-01-01

    Explosions and bombings are the most common deliberate cause of disasters with large numbers of casualties. Despite this fact, disaster medical response training has traditionally focused on the management of injuries following natural disasters and terrorist attacks with biological, chemical, and nuclear agents. The following article is a clinical primer for physicians regarding traumatic brain injury (TBI) caused by explosions and bombings. The history, physics, and treatment of TBI are outlined. PMID:20606794

  10. Weapons Experiments Division Explosives Operations Overview

    SciTech Connect

    Laintz, Kenneth E. [Los Alamos National Laboratory

    2012-06-19

    Presentation covers WX Division programmatic operations with a focus on JOWOG-9 interests. A brief look at DARHT is followed by a high level overview of explosives research activities currently being conducted within in the experimental groups of WX-Division. Presentation covers more emphasis of activities and facilities at TA-9 as these efforts have been more traditionally aligned with ongoing collaborative explosive exchanges covered under JOWOG-9.

  11. Explosive parcel containment and blast mitigation container

    DOEpatents

    Sparks, Michael H. (Frederick County, MD)

    2001-06-12

    The present invention relates to a containment structure for containing and mitigating explosions. The containment structure is installed in the wall of the building and has interior and exterior doors for placing suspicious packages into the containment structure and retrieving them from the exterior of the building. The containment structure has a blast deflection chute and a blowout panel to direct over pressure from explosions away from the building, surrounding structures and people.

  12. Intravesical explosions during transurethral endoscopic procedures

    Microsoft Academic Search

    A. Khan; J. Masood; M. Ghei; Z. Kasmani; A. J. Ball; R. Miller

    2007-01-01

    Every Urologist, during the course of fulguration treatment of bladder tumours, has at some time or another experienced small\\u000a intravesical explosions usually manifesting as a “pop”. Major intravesical explosions are rare but potentially devastating\\u000a complications of transurethral endoscopic resections. The damage to the bladder can range from small mucosal tears to bladder\\u000a rupture, which can either be intraperitoneal (requiring laparotomy

  13. Projectile-generating explosive access tool

    DOEpatents

    Jakaboski, Juan-Carlos (Albuquerque, NM; Hughs, Chance G. (Tijeras, NM); Todd, Steven N. (Rio Rancho, NM)

    2011-10-18

    An explosive device that can generate a projectile from the opposite side of a wall from the side where the explosive device is detonated. The projectile can be generated without breaching the wall of the structure or container. The device can optionally open an aperture in a solid wall of a structure or a container and form a high-kinetic-energy projectile from the portion of the wall removed to create the aperture.

  14. Projectile-generating explosive access tool

    DOEpatents

    Jakaboski, Juan-Carlos; Hughs, Chance G; Todd, Steven N

    2013-06-11

    A method for generating a projectile using an explosive device that can generate a projectile from the opposite side of a wall from the side where the explosive device is detonated. The projectile can be generated without breaching the wall of the structure or container. The device can optionally open an aperture in a solid wall of a structure or a container and form a high-kinetic-energy projectile from the portion of the wall removed to create the aperture.

  15. Plant tissue analysis for explosive compounds in phytoremediation and phytoforensics

    Microsoft Academic Search

    Adcharee Karnjanapiboonwong; Ruipu Mu; Yuan Yuan; Honglan Shi; Yinfa Ma; Joel G. Burken

    2012-01-01

    Plant tissue analysis methods were evaluated for six explosive compounds to assess uptake and phytoforensic methods development to quantify explosives in plant to obtain the plant data for the evaluation of explosive contamination in soil and groundwater. Four different solvent mixtures containing acetonitrile or methanol were tested at variable extraction ratios to compare the extraction efficiency for six explosive compounds:

  16. Numerical simulation on laser initiation of thin explosive

    Microsoft Academic Search

    Shiro Kubota; Hideki Shimada; Kikuo Matsui; Kunihito Nagayama

    2001-01-01

    The phenomenon of laser initiation of high explosive is examined using one-dimensional hydrodynamic code. Because the high explosive instantaneously absorbs the laser energy, the absorption process is ignored in this calculation. Initial condition for high explosive after absorption of energy assumed to follow Lambert's laws. In this study, how the thickness of explosive, the energy density of laser pulse and

  17. Forensic Identification of Inorganic Explosives by Ion Chromatography

    Microsoft Academic Search

    Greg W. Dicinoski; Robert A. Shellie; Paul R. Haddad

    2006-01-01

    While there is a great deal of published literature describing methods for the analysis of organic explosives by various methods, there are comparatively few publications concerning the analysis of explosives based on inorganic chemicals. This mini?review examines the literature that is concerned with the analysis of such explosives, commonly referred to as improvised explosive devices, using ion chromatography. Pertinent details

  18. Model of Impact Initiation of Composite Explosive Solid Systems

    Microsoft Academic Search

    A. V. Dubovik

    2002-01-01

    A model of mechanical initiation of solid explosives, applicable for analysis of sensitivity of individual substances and composite explosives, is developed. The model includes a system of equations of work softening of a high explosive charge under an impact, resulting dissipative heating, and heat release due to chemical reactions between the components of the explosive mixture. The critical parameters and

  19. ARMA 10-473 Comparison between elasto-plastic and rigid-plastic cohesive surface

    E-print Network

    Regueiro, Richard A.

    ARMA 10-473 Comparison between elasto-plastic and rigid-plastic cohesive surface elements- plastic (EP) and rigid-plastic (RP) cohesive surface finite element (CSE) implementations of cracking). For the CSE, we will consider elasto-plastic and rigid-plastic for- mulations, where the rigid-plastic

  20. Solid Rocket Launch Vehicle Explosion Environments

    NASA Technical Reports Server (NTRS)

    Richardson, E. H.; Blackwood, J. M.; Hays, M. J.; Skinner, T.

    2014-01-01

    Empirical explosion data from full scale solid rocket launch vehicle accidents and tests were collected from all available literature from the 1950s to the present. In general data included peak blast overpressure, blast impulse, fragment size, fragment speed, and fragment dispersion. Most propellants were 1.1 explosives but a few were 1.3. Oftentimes the data from a single accident was disjointed and/or missing key aspects. Despite this fact, once the data as a whole was digitized, categorized, and plotted clear trends appeared. Particular emphasis was placed on tests or accidents that would be applicable to scenarios from which a crew might need to escape. Therefore, such tests where a large quantity of high explosive was used to initiate the solid rocket explosion were differentiated. Also, high speed ground impacts or tests used to simulate such were also culled. It was found that the explosions from all accidents and applicable tests could be described using only the pressurized gas energy stored in the chamber at the time of failure. Additionally, fragmentation trends were produced. Only one accident mentioned the elusive "small" propellant fragments, but upon further analysis it was found that these were most likely produced as secondary fragments when larger primary fragments impacted the ground. Finally, a brief discussion of how this data is used in a new launch vehicle explosion model for improving crew/payload survival is presented.

  1. Experimental Explosive Characterization for Counterterrorist Investigation

    NASA Astrophysics Data System (ADS)

    Etayo, D.; Maestrojuan, I.; Teniente, J.; Ederra, I.; Gonzalo, R.

    2013-08-01

    A THz spectral characterization of different explosives of special interest for the Spanish National Security Forces "Guardia Civil" is presented in this paper. This forensic analysis has been done in the frequency range from 0.060 THz to 3.5 THz using the Teraview TPS Spectra 3000 system in laboratory conditions. With this equipment the refractive index, absorbance and complex permittivity of the explosive samples have been obtained. In this study, some of the most common used explosives (Bullet gunpowder, mine gunpowder, PETN, TNT, RDX) are analysed paying special attention to differences related to the manufacturing process used to elaborate some of them and to the purity of the samples. The different fabrication processes of the explosives lead to the same spectral behaviour and characteristics. At the same time, the inclusion of some additives in the explosive samples does not alter their main electromagnetic properties. The sensitivity limit of the measurement system has been found to be to 10 mg of explosives. These results will be used to design future THz imaging systems that allow to detect and identify them in security and defence applications and/or to complete laboratory studies after a terrorist action.

  2. Explosive vapor detection payload for small robots

    NASA Astrophysics Data System (ADS)

    Stimac, Phil J.; Pettit, Michael; Wetzel, John P.; Haas, John W.

    2013-05-01

    Detection of explosive hazards is a critical component of enabling and improving operational mobility and protection of US Forces. The Autonomous Mine Detection System (AMDS) developed by the US Army RDECOM CERDEC Night Vision and Electronic Sensors Directorate (NVESD) is addressing this challenge for dismounted soldiers. Under the AMDS program, ARA has developed a vapor sampling system that enhances the detection of explosive residues using commercial-off-the-shelf (COTS) sensors. The Explosives Hazard Trace Detection (EHTD) payload is designed for plug-and-play installation and operation on small robotic platforms, addressing critical Army needs for more safely detecting concealed or exposed explosives in areas such as culverts, walls and vehicles. In this paper, we describe the development, robotic integration and performance of the explosive vapor sampling system, which consists of a sampling "head," a vapor transport tube and an extendable "boom." The sampling head and transport tube are integrated with the boom, allowing samples to be collected from targeted surfaces up to 7-ft away from the robotic platform. During sample collection, an IR lamp in the sampling head is used to heat a suspected object/surface and the vapors are drawn through the heated vapor transport tube to an ion mobility spectrometer (IMS) for detection. The EHTD payload is capable of quickly (less than 30 seconds) detecting explosives such as TNT, PETN, and RDX at nanogram levels on common surfaces (brick, concrete, wood, glass, etc.).

  3. Spectroscopic characterization of nitroaromatic landmine signature explosives

    NASA Astrophysics Data System (ADS)

    Hernandez-Rivera, Samuel P.; Manrique-Bastidas, Cesar A.; Blanco, Alejandro; Primera, Oliva M.; Pacheco, Leonardo C.; Castillo-Chara, Jairo; Castro, Miguel E.; Mina, Nairmen

    2004-09-01

    TNT and DNT are important explosives used as base charges of landmines and other explosive devices. They are often combined with RDX in specific explosive formulations. Their detection in vapor phase as well as in soil in contact with the explosives is important in landmine detection technology. The spectroscopic signatures of nitroaromatic compounds in neat forms: crystals, droplets, and recrystallized samples were determined by Raman Microspectroscopy (RS), Fourier Transform Infrared Microscopy (FTIR) and Fiber Optics Coupled - Fourier Transform Infrared Spectroscopy (FOC-FTIR) using a grazing angle (GA) probe. TNT exhibits a series of characteristic bands: vibrational signatures, which allow its detection in soil. The spectroscopic signature of neat TNT is dominated by strong bands about 1380 and 2970 cm-1. The intensity and position of these bands were found remarkably different in soil samples spiked with TNT. The 1380 cm-1 band is split into a number of bands in that region. The 2970 cm-1 band is reduced in intensity and new bands are observed about 2880 cm-1. The results are consistent with a different chemical environment of TNT in soil as compared to neat TNT. Interactions were found to be dependent on the physical source of the explosive. In the case of DNT-sand interactions, shifts in vibrational frequencies of the explosives as well as the substrates were found.

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

    NASA Astrophysics Data System (ADS)

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

    2009-12-01

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

  5. Isentropic Compression driven by high-explosive: application to Ti-6Al-4V

    NASA Astrophysics Data System (ADS)

    Voltz, Christophe; Sollier, Arnaud; Maillet, Jean-Bernard; Bouyer, Viviane

    2009-06-01

    We report on a n isentropic compression experiment of Ti-6Al-4V alloy based on the use of the release of detonation products from a high-explosive to generate a ramp wave compression in a multisteps target. VISAR and DLI measurements of the rear free surface velocities of the different steps allow computing the sound velocity of the material during its compression, which is characteristic of the EOS of the material. The experiment device is described and the sound velocities measurements are analyzed. The results are compared with 2-dimensional elasto-plastic simulations.

  6. Characterization of explosive devices in luggage: Initial results of the ART-IIC test series

    SciTech Connect

    Akerman, M.A.; Kass, M.D. [Oak Ridge National Lab., TN (United States); Clough, B.T. [Wright Lab., Wright-Patterson AFB, OH (United States)

    1993-12-31

    Characteristics and damage associated with exploded luggage aboard aircraft are presented in this paper. Plastic-sided suitcases filled with typical travel possessions were exploded inside the fuselage of decomissioned B-52 aircraft. Multilayered shield panels, mounted to one side of the fuselage, served to protect the aircraft body and flight system components from both the blast wave and exploded fragments. The resulting damage produced by the explosions was characterized and the absorbing characteristics of the shielding were evaluated. In addition, the energy of the luggage fragments was estimated.

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

    SciTech Connect

    Reaugh, J E

    2008-10-15

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

  8. Spherical combustion clouds in explosions

    NASA Astrophysics Data System (ADS)

    Kuhl, A. L.; Bell, J. B.; Beckner, V. E.; Balakrishnan, K.; Aspden, A. J.

    2013-05-01

    This study explores the properties of spherical combustion clouds in explosions. Two cases are investigated: (1) detonation of a TNT charge and combustion of its detonation products with air, and (2) shock dispersion of aluminum powder and its combustion with air. The evolution of the blast wave and ensuing combustion cloud dynamics are studied via numerical simulations with our adaptive mesh refinement combustion code. The code solves the multi-phase conservation laws for a dilute heterogeneous continuum as formulated by Nigmatulin. Single-phase combustion (e.g., TNT with air) is modeled in the fast-chemistry limit. Two-phase combustion (e.g., Al powder with air) uses an induction time model based on Arrhenius fits to Boiko's shock tube data, along with an ignition temperature criterion based on fits to Gurevich's data, and an ignition probability model that accounts for multi-particle effects on cloud ignition. Equations of state are based on polynomial fits to thermodynamic calculations with the Cheetah code, assuming frozen reactants and equilibrium products. Adaptive mesh refinement is used to resolve thin reaction zones and capture the energy-bearing scales of turbulence on the computational mesh (ILES approach). Taking advantage of the symmetry of the problem, azimuthal averaging was used to extract the mean and rms fluctuations from the numerical solution, including: thermodynamic profiles, kinematic profiles, and reaction-zone profiles across the combustion cloud. Fuel consumption was limited to ˜ 60-70 %, due to the limited amount of air a spherical combustion cloud can entrain before the turbulent velocity field decays away. Turbulent kinetic energy spectra of the solution were found to have both rotational and dilatational components, due to compressibility effects. The dilatational component was typically about 1 % of the rotational component; both seemed to preserve their spectra as they decayed. Kinetic energy of the blast wave decayed due to the pressure field. Turbulent kinetic energy of the combustion cloud decayed due to enstrophy overline{? 2} and dilatation overline{? 2}.

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

    SciTech Connect

    Furmanski, Jevan [Los Alamos National Laboratory; Rae, Philip [Los Alamos National Laboratory; Clements, Bradford E. [Los Alamos National Laboratory

    2012-06-05

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

  10. Influence of Mechanical Properties of Aerial Shells made from Biodegradable Plastics on Smaller Fragmentation

    NASA Astrophysics Data System (ADS)

    Kudo, Makoto; Murata, Kenji; Kamata, Satoru; Hamada, Fumio

    In this paper, a new aerial shell made of biodegradable plastics was developed and explosion tests were carried out using 2.5-10 gou-size firework aerial shells at a ground test site in order to observe the fragmentation. The dispersed fragments were then collected and their size and distribution measured. In order to monitor the fragmentation visually, a high-speed camera was used to film the ignition of the bursting charge and the scattering of the shell fragments. The shell fragments became much smaller, because mechanical properties of biodegradable plastics that were added improved polyvinyl alcohol (PVA) and chaff powder (CP). Fibrillation was seen in PBS/PVA/CP, and it seemed effective for mechanical properties. As a result, safer aerial shells which disperse into smaller fragments on explosion were successfully developed.

  11. Presynaptic long-term plasticity

    PubMed Central

    Yang, Ying; Calakos, Nicole

    2013-01-01

    Long-term synaptic plasticity is a major cellular substrate for learning, memory, and behavioral adaptation. Although early examples of long-term synaptic plasticity described a mechanism by which postsynaptic signal transduction was potentiated, it is now apparent that there is a vast array of mechanisms for long-term synaptic plasticity that involve modifications to either or both the presynaptic terminal and postsynaptic site. In this article, we discuss current and evolving approaches to identify presynaptic mechanisms as well as discuss their limitations. We next provide examples of the diverse circuits in which presynaptic forms of long-term synaptic plasticity have been described and discuss the potential contribution this form of plasticity might add to circuit function. Finally, we examine the present evidence for the molecular pathways and cellular events underlying presynaptic long-term synaptic plasticity. PMID:24146648

  12. The volcanic explosivity index \\/VEI\\/ - An estimate of explosive magnitude for historical volcanism

    Microsoft Academic Search

    C. G. Newhall; Stephen Self

    1982-01-01

    A composite estimate of the magnitude of past explosive eruptions, referred to as the Volcanic Explosivity Index (VEI), is proposed as a semiquantitative compromise between poor data and the need in various disciplines to evaluate the record of past volcanism. The VEI is assigned to more than 8000 historic and prehistoric eruptions. It is shown that the VEI can help

  13. Initiation of dust explosions by electric spark discharges triggered by the explosive dust cloud itself

    Microsoft Academic Search

    Erlend Randeberg; Rolf K. Eckhoff

    2006-01-01

    An investigation of ignition of dust clouds by the use of electric spark discharges triggered by the explosive dust cloud itself has been conducted. This method of triggering capacitive sparks probably represents a realistic mechanism for initiating accidental dust explosions in industrial practice. Unlike the conventional method for determining the minimum ignition energy (MIE) in the laboratory, the delay between

  14. Studies of the laser-induced fluorescence of explosives and explosive compositions.

    SciTech Connect

    Hargis, Philip Joseph, Jr. (,; .); Thorne, Lawrence R.; Phifer, Carol Celeste; Parmeter, John Ethan; Schmitt, Randal L.

    2006-10-01

    Continuing use of explosives by terrorists throughout the world has led to great interest in explosives detection technology, especially in technologies that have potential for standoff detection. This LDRD was undertaken in order to investigate the possible detection of explosive particulates at safe standoff distances in an attempt to identify vehicles that might contain large vehicle bombs (LVBs). The explosives investigated have included the common homogeneous or molecular explosives, 2,4,6-trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN), cyclonite or hexogen (RDX), octogen (HMX), and the heterogeneous explosive, ammonium nitrate/fuel oil (ANFO), and its components. We have investigated standard excited/dispersed fluorescence, laser-excited prompt and delayed dispersed fluorescence using excitation wavelengths of 266 and 355 nm, the effects of polarization of the laser excitation light, and fluorescence imaging microscopy using 365- and 470-nm excitation. The four nitro-based, homogeneous explosives (TNT, PETN, RDX, and HMX) exhibit virtually no native fluorescence, but do exhibit quenching effects of varying magnitude when adsorbed on fluorescing surfaces. Ammonium nitrate and fuel oil mixtures fluoresce primarily due to the fuel oil, and, in some cases, due to the presence of hydrophobic coatings on ammonium nitrate prill or impurities in the ammonium nitrate itself. Pure ammonium nitrate shows no detectable fluorescence. These results are of scientific interest, but they provide little hope for the use of UV-excited fluorescence as a technique to perform safe standoff detection of adsorbed explosive particulates under real-world conditions with a useful degree of reliability.

  15. Plasticity of immunological synapses.

    PubMed

    Valitutti, Salvatore; Dupré, Loïc

    2010-01-01

    TCR engagement with peptide/MHC complexes displayed on the surface of the antigen-presenting cells is the crucial event in developing an adaptive immune response and occurs within specialized signaling areas named immunological synapses. Immunological synapses are diverse both in structure and function and exhibit a strikingly dynamic molecular organization. In this review, we focus on the diversity of immunological synapses and on their plasticity in response to stimulation. We discuss how the study of the adaptable features of immunological synapses can be instrumental to a better understanding of the complex regulation of adaptive immunity. PMID:19960316

  16. ABS plastic RPCs

    SciTech Connect

    Ables, E.; Bionta, R.; Olson, H.; Ott, L.; Parker, E.; Wright, D.; Wuest, C

    1996-02-01

    After investigating a number of materials, we discovered that an ABS plastic doped with a conducting polymer performs well as the resistive electrode in a narrow gap RPC (resistive plate chamber). Operating in the streamer mode, we find efficiencies of 90-96% with low noise and low strip multiplicities. We have also studied a variety of operating gases and found that a mixture containing SF{sub 6}, a non-ozone depleting gas, argon and isobutane gives good streamer mode performance, even with isobutane concentrations of 20% or less.

  17. Fabrication of plastic biochips

    SciTech Connect

    Saaem, Ishtiaq; Ma, Kuo-Sheng; Alam, S. Munir; Tian Jingdong [Department of Biomedical Engineering and Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina 27708 (United States); Department of Medicine and Human Vaccine Institute, Duke University, Durham, North Carolina 27708 (United States); Department of Biomedical Engineering and Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina 27708 (United States)

    2010-07-15

    A versatile surface functionalization procedure based on rf magnetron sputtering of silica was performed on poly(methylmethacrylate), polycarbonate, polypropylene, and cyclic olefin copolymers (Topas 6015). The hybrid thermoplastic surfaces were characterized by x-ray photoelectron spectrometer analysis and contact angle measurements. The authors then used these hybrid materials to perform a sandwich assay targeting an HIV-1 antibody using fluorescent detection and biotinylated peptides immobilized using the bioaffinity of biotin-neutravidin. They found a limit of detection similar to arrays on glass surfaces and believed that this plastic biochip platform may be used for the development of disposable immunosensing and diagnostic applications.

  18. Biodegradable plastics from renewable sources

    Microsoft Academic Search

    M. Flieger; M. Kantorová; A. Prell; T. ?ezanka; J. Votruba

    2003-01-01

    Plastic waste disposal is a huge ecotechnological problem and one of the approaches to solving this problem is the development\\u000a of biodegradable plastics. This review summarizes data on their use, biodegradability, commercial reliability and production\\u000a from renewable resources. Some commercially successful biodegradable plastics are based on chemical synthesis (i.e. polyglycolic acid, polylactic acid, polycaprolactone, and polyvinyl alcohol). Others are products

  19. Polyolefins as additives in plastics

    SciTech Connect

    Deanin, R.D. [Univ. of Massachusetts at Lowell, MA (United States)

    1993-12-31

    Polyolefins are not only major commodity plastics - they are also very useful as additives, both in other polyolefins and also in other types of plastics. This review covers ethylene, propylene, butylene and isobutylene polymers, in blends with each other, and as additives to natural rubber, styrene/butadiene rubber, polystyrene, polyvinyl chloride, polymethyl methacrylate, polyphenylene oxide, polycarbonate, thermoplastic polyesters, polyurethanes, polyamides, and mixed automotive plastics recycling.

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

    NASA Astrophysics Data System (ADS)

    Galland, O.; Gisler, G. R.; Haug, Ø. T.

    2014-06-01

    Shallow explosive volcanic processes, such as kimberlite volcanism and 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. Using dimensional analysis, we identified key governing dimensionless parameters, in particular the gravitational stress-to-fluid pressure ratio (?2 = P/?gh) and the fluid pressure-to-host rock strength ratio (?3 = 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 ?2 on vent morphology and dynamics. A phase diagram demonstrates a separation between two distinct morphologies, with vertical structures occurring at high values of ?2 and diagonal ones at low values of ?2. The numerical simulations were used to test the effect of ?3 on vent morphology and dynamics. In the numerical models we see three distinct morphologies: vertical pipes are produced at high values of ?3, diagonal pipes at low values of ?3, and horizontal sills at intermediate values of ?3. Our results show that vertical pipes form by plasticity-dominated yielding in high-energy systems (high ?2 and ?3), whereas diagonal and horizontal vents dominantly form by fracturing in lower energy systems (low ?2 and ?3). Although our models are two-dimensional, 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.

  1. Report on the treatability study for inerting small quantities of radioactive explosives and explosive components

    SciTech Connect

    Loyola, V.M.; Reber, S.D.

    1996-02-01

    As a result of Sandia`s radiation hardening testing on a variety of its explosive components, radioactive waste streams were generated and have to be disposed of as radioactive waste. Due to the combined hazards of explosives and radioactivity, Sandia`s Radioactive and Mixed Waste Management organization did not have a mechanism for disposal of these waste streams. This report documents the study done to provide a method for the removal of the explosive hazard from those waste streams. The report includes the design of the equipment used, procedures followed, results from waste stream analog tests and the results from the actual explosive inerting tests on radioactive samples. As a result of the inerting treatment, the waste streams were rendered non-explosive and, thus, manageable through normal radioactive waste disposal channels.

  2. LIBS Detection of Explosives in Traces

    NASA Astrophysics Data System (ADS)

    Moros, Javier; Fortes, Francisco J.; Vadillo, Jose M.; Laserna, J. Javier

    Laser-induced breakdown spectroscopy is one of the most exciting topics in the whole field of analytical science. Among the several expanding applications of LIBS, the analysis of explosives is gaining acceptance due to the unique capabilities of LIBS for inspection of distant samples, for recognition of materials behind a barrier or for identification of objects in motion, to name just a few examples. Although LIBS is a technique for elemental analysis, recent insights in the understanding of the chemistry of plasma plumes have boosted the use of LIBS for identification of organic compounds. In this chapter, the uses of LIBS for the detection, sorting and identity assignment of explosives is reviewed. The first section of this contribution is devoted to the fundamentals of explosives responses, with a discussion of the strong and weak points of LIBS for this application. The next section deals with the specific instrumentation used for laboratory and field work, from man-portable units to stand-off systems. A discussion on the several chemometric tools used for identification and sorting of explosives follows. Data fusion strategies for improving the distinction between harmless and explosive compounds are presented. Finally, a conclusions section outlines the current achievements and the future needs in this application.

  3. Swell Sleeves for Testing Explosive Devices

    NASA Technical Reports Server (NTRS)

    Hinkel, Todd J.; Dean, Richard J.; Hohmann, Carl W.; Hacker, Scott C.; Harrington, Douglas W.; Bacak, James W.

    2003-01-01

    A method of testing explosive and pyrotechnic devices involves exploding the devices inside swell sleeves. Swell sleeves have been used previously for measuring forces. In the present method, they are used to obtain quantitative indications of the energy released in explosions of the devices under test. A swell sleeve is basically a thick-walled, hollow metal cylinder threaded at one end to accept a threaded surface on a device to be tested (see Figure 1). Once the device has been tightly threaded in place in the swell sleeve, the device-and-swell-sleeve assembly is placed in a test fixture, then the device is detonated. After the explosion, the assembly is removed from the test fixture and placed in a coordinate-measuring machine for measurement of the diameter of the swell sleeve as a function of axial position. For each axial position, the original diameter of the sleeve is subtracted from the diameter of the sleeve as swollen by the explosion to obtain the diametral swelling as a function of axial position (see Figure 2). The amount of swelling is taken as a measure of the energy released in the explosion. The amount of swelling can be compared to a standard amount of swelling to determine whether the pyrotechnic device functioned as specified.

  4. Review of Nuclear Methodologies for Explosive Detection

    NASA Astrophysics Data System (ADS)

    Womble, Phillip C.; Vourvopoulos, George; Novikov, Ivan; Paschal, Jon

    2001-10-01

    Nuclear techniques show a number of advantages for non-destructive elemental characterization. These include the ability to examine bulk quantities with speed, high elemental specificity, and no memory effects from the previously measured object. These qualities are important for an effective detection system for explosives and drugs. High explosives (TNT, RDX, C-4, etc.) are composed primarily of the chemical elements hydrogen, carbon, nitrogen, and oxygen. Many innocuous materials are also primarily composed of these same elements. These elements, however, are found in each material with very different elemental ratios and concentrations. It is thus possible to identify and differentiate e.g. TNT from paraffin. For narcotics, the C/O ratio is at least a factor of two larger than the innocuous materials. Explosives have been shown to be differentiated by the utilization of both C/O ratio and N/O ratios. The problem of identifying explosives is thus reduced to the problem of elemental identification and quantization. We will review the methods of explosive detection with emphasis on nuclear techniques. We will discuss where improvements are desired on current techniques for landmine detection and unexploded ordnance.

  5. The 1908 Tunguska Explosion and Its Analogs

    NASA Astrophysics Data System (ADS)

    Ibadov, Subhon; Ibodov, Firuz S.; Grigoryan, Samvel S.

    The 1908 June 30 Tunguska explosion event, which occured one hundred years ago, is analysed together with the origin of such explosive events as flaring meteors, exploding bolides and some kind of solar flares. These events are explained analytically by aerodynamic fragmentation of cosmic bodies like comets, asteroids, meteoroids in the atmospheres of celestial objects accompanied by transversal expansion of the fragmented mass. The sharp stopping and impulsive thermalization of the kinetic energy of the disk-like high-velocity fragmented mass occuring mainly within a short distance dz=0.7H where H is the scale height of the atmosphere, lead to impulsive generation of high-temperarure phase in the zone dz. The energetics of the process is 1024 erg for Tunguska event caused by explosion of 100-meter meteoroid in the Earth atmosphere and 1032 erg for solar flares caused by Comet Halley like bodies exploding near the solar surface. It is promising to optically monitor the Earth atmosphere from space by SPACEWATCH- like missions as well as to observe sun-grazing comets penetrating the solar chromosphere and photosphere by SOHO-like space telescopes, to study the nature of explosive events like the 1908 Tunguska explosion as well as impact-generated photospheric solar flares.

  6. Biochemical machining — biochemical removal process of plastic

    Microsoft Academic Search

    Toshiaki Kaneeda; Seiichi Yokomizo; Akio Miwa; Kazuta Mitsuishi; Yoshiyuki Uno; Hiroyuki Morioka

    1997-01-01

    Plastic products are now ubiquitos; however, home and industrial plastic waste cannot be degraded. Hence, disposal of such wastes is now a large problem in maintining a clean environment. Some biodegradable plastics have been developed in response to demands for waste-free plastic products. Biodegradable Editorial Board plastics can be degraded by microorganism or enymes by means of cutting down the

  7. Waste Toolkit A-Z Plastic Grundon

    E-print Network

    Melham, Tom

    Waste Toolkit A-Z Plastic ­ Grundon Also see `Swap Shop' and `Office Recycling ­ Grundon' in the Waste Toolkit A-Z How can I recycle plastic? There are lots of different types of plastic. Typically, waste contractors can only recycle PETE plastic and HDPE plastic. The University's preferred waste

  8. Plastics recycling: challenges and opportunities

    PubMed Central

    Hopewell, Jefferson; Dvorak, Robert; Kosior, Edward

    2009-01-01

    Plastics are inexpensive, lightweight and durable materials, which can readily be moulded into a variety of products that find use in a wide range of applications. As a consequence, the production of plastics has increased markedly over the last 60 years. However, current levels of their usage and disposal generate several environmental problems. Around 4 per cent of world oil and gas production, a non-renewable resource, is used as feedstock for plastics and a further 3–4% is expended to provide energy for their manufacture. A major portion of plastic produced each year is used to make disposable items of packaging or other short-lived products that are discarded within a year of manufacture. These two observations alone indicate that our current use of plastics is not sustainable. In addition, because of the durability of the polymers involved, substantial quantities of discarded end-of-life plastics are accumulating as debris in landfills and in natural habitats worldwide. Recycling is one of the most important actions currently available to reduce these impacts and represents one of the most dynamic areas in the plastics industry today. Recycling provides opportunities to reduce oil usage, carbon dioxide emissions and the quantities of waste requiring disposal. Here, we briefly set recycling into context against other waste-reduction strategies, namely reduction in material use through downgauging or product reuse, the use of alternative biodegradable materials and energy recovery as fuel. While plastics have been recycled since the 1970s, the quantities that are recycled vary geographically, according to plastic type and application. Recycling of packaging materials has seen rapid expansion over the last decades in a number of countries. Advances in technologies and systems for the collection, sorting and reprocessing of recyclable plastics are creating new opportunities for recycling, and with the combined actions of the public, industry and governments it may be possible to divert the majority of plastic waste from landfills to recycling over the next decades. PMID:19528059

  9. [Postoperative complications in plastic surgery].

    PubMed

    Vogt, P M

    2009-09-01

    Plastic surgery covers a broad spectrum of diseases and conditions in the areas of reconstructive surgery, hand, burn and aesthetic surgery. Besides acquired defects or malformations an increasing number of patients are being treated for surgical or multimodal complications. In a considerable number of patients plastic and reconstructive surgery remains the only therapeutic alternative after other therapy has failed. Therefore complication management in plastic surgery is of utmost importance for a successful outcome. In addition patient expectations in the results of plastic surgery as a discipline of invention and problem solving are steadily increasing. This challenge is reflected in clinical patient management by intensive research in tissue engineering and regenerative medicine. Patients in plastic surgery are recruited from all age groups of either gender, involving traumatic and oncologic as well as congenital and aesthetic disorders. The demographics of aging, multimorbidity and obesity pose new challenges to plastic surgery. Although age over 70 years is not an independent risk factor per se for complications in plastic surgery, e.g. for complex free flap transfer, medical problems are present at a higher rate, which is to be expected in this age group. Risk factors such as alcoholism and coronary heart diseases seem to be independent predictors of perioperative complications. Therefore older patients can also benefit from plastic surgery and recurrent operations by the corresponding risk and complication management. Complication management necessitates careful patient selection, estimation of operative risks and patient-adapted selection of procedures. In addition to expertise in plastic surgery a thorough knowledge of non-surgical and surgical back-up procedures for technical incidents as well as vascular circulatory and wound healing disorders is required to deal successfully with complications in plastic surgery. This article presents these specific aspects of postoperative complication management in plastic surgery. PMID:19669715

  10. Fine ash content of explosive eruptions

    NASA Astrophysics Data System (ADS)

    Rose, W. I.; Durant, A. J.

    2009-09-01

    In explosive eruptions, the mass proportion of ash that is aerodynamically fine enough to cause problems with jet aircraft or human lungs (< 30 to 60 ?m in diameter) is in the range of a few percent to more than 50%. The proportions are higher for silicic explosive eruptions, probably because vesicle size in the pre-eruptive magma is smaller than those in mafic magmas. There is good evidence that pyroclastic flows produce high proportions of fine ash by communition and it is likely that this process also occurs inside volcanic conduits and would be most efficient when the magma fragmentation surface is well below the summit crater. Reconstructed total grain size distributions for several recent explosive eruptions indicate that basaltic eruptions have small proportions of very fine ash (~ 1 to 4%) while tephra generated during silicic eruptions contains large proportions (30 to > 50%).

  11. Local magnitudes of small contained explosions.

    SciTech Connect

    Chael, Eric Paul

    2009-12-01

    The relationship between explosive yield and seismic magnitude has been extensively studied for underground nuclear tests larger than about 1 kt. For monitoring smaller tests over local ranges (within 200 km), we need to know whether the available formulas can be extrapolated to much lower yields. Here, we review published information on amplitude decay with distance, and on the seismic magnitudes of industrial blasts and refraction explosions in the western U. S. Next we measure the magnitudes of some similar shots in the northeast. We find that local magnitudes ML of small, contained explosions are reasonably consistent with the magnitude-yield formulas developed for nuclear tests. These results are useful for estimating the detection performance of proposed local seismic networks.

  12. Tire explosion injuries to the upper extremity.

    PubMed

    Matloub, H S; Prevel, C D; Sanger, J R; Yousif, N J; Devine, C A; Romano, J

    1992-12-01

    Several articles have been published that bring attention to the destructive potential of tire explosions. Although the severity of tire explosion injuries to the head and neck region is well established, only one previous article has reported injuries to the upper extremity. Fourteen patients with upper extremity tire explosion injuries have been treated by us from 1980 to 1988. Each injury was caused by single-piece wheel assemblies, as opposed to multipiece wheel assemblies, which have traditionally been associated with the injury. Three representative patient reports are discussed. Prevention of this injury can be achieved by increased public awareness, formal industrial safety training, tire servicing with dedicated equipment including restraining devices or barriers, complete evaluation of wheel/tire serviceability before tire mounting, separation of servicing of single and multipiece wheels, and complete tire deflation before servicing. PMID:1466553

  13. Optimal coherent control methods for explosives detection

    NASA Astrophysics Data System (ADS)

    Moore, D. S.; McGrane, S. D.; Greenfield, M. T.; Scharff, R. J.

    2012-06-01

    We are utilizing control of molecular processes at the quantum level via the best capabilities of recent laser technology and recent discoveries in optimal shaping of laser pulses to significantly enhance the detection of explosives. Optimal dynamic detection of explosives (ODD-Ex) is a methodology whereby laser pulses are optimally shaped to simultaneously enhance the sensitivity and selectivity of any of a wide variety of spectroscopic methods for explosives signatures while reducing the influence of noise and environmental perturbations. We discuss here recent results using the Gerchberg-Saxton algorithm to provide an optimal shaped laser pulse for selective coherent anti-Stokes Raman signal generation of a single component in a mixture.

  14. Remote detection of explosives with multispectral imaging

    NASA Astrophysics Data System (ADS)

    Schau, H. C.

    2009-05-01

    Despite its renewed interest, remote sensing of explosives has proven to be difficult due to the low vapor pressure of the agents. In this paper we discuss a method to detect residue of explosive agents on fabric and clothing using Multi Spectral Imaging. Such a technique will aid in the detection of bomb making activities and individuals. While limited to line of sight only, Multi Spectral Imaging has much to recommend it including inspection of clothing in public places, luggage, and potential locations for bomb manufacture. This paper presents the basic techniques developed for detection of trace TNT and reports the results of several limited field trials. Imaging hardware is discussed and processing methodology is reviewed with some demonstrations of the identification difficulty for explosives and other false targets commonly found. The use of other spectral bands is presented with the goal of eliminating common false targets.

  15. Geophysical and geochemical consequences of nuclear explosions

    NASA Astrophysics Data System (ADS)

    Smith, Joseph V.

    An all-Union session on the geophysical and geochemical consequences of nuclear explosions was commissioned by the AGU Public Affairs Committee and will be given at San Francisco Wednesday morning, December 7, 1983. The session is deliberately restricted to aspects within the domain of the American Geophysical Union, and the social, political, and ethical issues will not be treated explicitly. It is inevitable that such issues will be present in the minds of the speakers and audience, but they cannot be evaluated by rigorous scientific methods. The aim of the session is to examine the possible range of geophysical and geochemical consequences of various scenarios involving nuclear explosions. Such scenarios extend from a single nuclear explosion to a major nuclear exchange involving thousands of weapons. A Wednesday afternoon session at the Fall Meeting will examine atmospheric consequences.

  16. DSD front models : nonideal explosive detonation

    SciTech Connect

    Bdzil, J. B. (John Bohdan); Short, M. (Mark Short); Aslam, T. D. (Tariq D.); Catanach, R. A. (Richard A.); Hill, L. G. (Larry G.)

    2001-01-01

    The Detonation Shock Dynamics (DSD) method for propagating detonation in numerical simulation of detonation in high explosive (HE) is based on three elements: (1) a subscale theory of multi-dimensional detonation that treats the evolving detonation as a front with dynamics that depends only on metrics of the front (such as curvature, etc.), (2) high-resolution direct numerical sirnuliltion of detonation serving both to test existing subscale theories and suggest modifications, and (3) physical experiments to characterize multi-dimensional detonation propagation on real explosives and to calibrate the front models for use in engineering simulations. In this paper we describe our work on all three of these elements of the DSD method as it applies to detonation in nonideal explosives.

  17. PINS Testing and Modification for Explosive Identification

    SciTech Connect

    E.H. Seabury; A.J. Caffrey

    2011-09-01

    The INL's Portable Isotopic Neutron Spectroscopy System (PINS)1 non-intrusively identifies the chemical fill of munitions and sealed containers. PINS is used routinely by the U.S. Army, the Defense Threat Reduction Agency, and foreign military units to determine the contents of munitions and other containers suspected to contain explosives, smoke-generating chemicals, and chemical warfare agents such as mustard and nerve gas. The objects assayed with PINS range from softball-sized M139 chemical bomblets to 200 gallon DOT 500X ton containers. INL had previously examined2 the feasibility of using a similar system for the identification of explosives, and based on this proof-of-principle test, the development of a dedicated system for the identification of explosives in an improvised nuclear device appears entirely feasible. INL has been tasked by NNSA NA-42 Render Safe Research and Development with the development of such a system.

  18. Nuclear Resonance Fluorescence Measurements of High Explosives

    SciTech Connect

    Caggiano, Joseph A.; Warren, Glen A.; Korbly, Steve; Hasty, R.; Klimenko, A.; Park, William H.

    2007-12-31

    Pacific Northwest National Laboratory and Passport Systems have collaborated to perform Nuclear Resonance Fluorescence experiments using several high quality high-explosive simulant samples. These measurements were conducted to determine the feasibility of finding and characterizing high explosive material by NRF interrogation. Electron beams of 5.1, 5.3, 8, and 10 MeV were used to produce bremsstrahlung photon beams, which irradiated the samples. The gamma-ray spectra were collected using high-purity germanium detectors. Nitrogen-to-carbon ratios of the high-explosive simulants were extracted from the 5.1 and 5.3 MeV data and compare favorably with accepted values. Analysis of the 8 and 10 MeV data is in progress; preliminary isotopic comparisons within the samples are consistent with the expected results.

  19. Electromagnetic Effects in SDF Explosions

    SciTech Connect

    Reichenbach, H; Neuwald, P; Kuhl, A L

    2010-02-12

    The notion of high ion and electron concentrations in the detonation of aluminized explosive mixtures has aroused some interest in electro-magnetic effects that the SDF charges might generate when detonated. Motivated by this interest we have started to investigate whether significant electro-magnetic effects show up in our small-scale experiments. However, the design of instrumentation for this purpose is far from straightforward, since there are a number of open questions. Thus the main aim of the feasibility tests is to find - if possible - a simple and reliable method that can be used as a diagnostic tool for electro-magnetic effects. SDF charges with a 0.5-g PETN booster and a filling of 1 g aluminum flakes have been investigated in three barometric bomb calorimeters with volumes ranging from 6.3 l to of 6.6 l. Though similar in volume, the barometric bombs differed in the length-to-diameter ratio. The tests were carried out with the bombs filled with either air or nitrogen at ambient pressure. The comparison of the test in air to those in nitrogen shows that the combustion of TNT detonation products or aluminum generates a substantial increase of the quasi-steady overpressure in the bombs. Repeated tests in the same configuration resulted in some scatter of the experimental results. The most likely reason is that the aluminum combustion in most or all cases is incomplete and that the amount of aluminum actually burned varies from test to test. The mass fraction burned apparently decreases with increasing aspect ratio L/D. Thus an L/D-ratio of about 1 is optimal for the performance of shock-dispersed-fuel combustion. However, at an L/D-ratio of about 5 the combustion still yields appreciable overpressure in excess of the detonation. For a multi-burst scenario in a tunnel environment with a number of SDF charges distributed along a tunnel section a spacing of 5 tunnel diameter and a fuel-specific volume of around 7 l/g might provide an acceptable compromise between optimizing the combustion performance and keeping the number of elementary charges low. Further tests in a barometric bomb calorimeter of 21.2 l volume were performed with four types of aluminum. The mass fraction burned in this case appeared to depend on the morphology of the aluminum particles. Flake aluminum exhibited a better performance than granulated aluminum with particle sizes ranging from below 25 {micro}m to 125 {micro}m for the coarsest material. In addition, a feasibility study on electro-magnetic effects from SDF charges detonated in a tunnel has been performed. A method was developed to measure the local, unsteady electro-conductivity in the detonation/combustion products cloud. This method proved to yield reproducible results. A variety of methods were tested with regard to probing electro-magnetic pulses from the detonation of SDF charges. The results showed little reproducibility and were small compared to the effect from pulsed high voltage discharges of comparatively small energy (around 32 J). Thus either no significant electromagnetic pulse is generated in our small-scale tests or the tested techniques have to be discarded as too insensitive or too limited in bandwidth to detect possibly very high frequency electro-magnetic disturbances.

  20. Probing thermonuclear supernova explosions with neutrinos

    E-print Network

    A. Odrzywolek; T. Plewa

    2011-03-27

    Aims: We present neutrino light curves and energy spectra for two representative type Ia supernova explosion models: a pure deflagration and a delayed detonation. Methods: We calculate the neutrino flux from $\\beta$ processes using nuclear statistical equilibrium abundances convoluted with approximate neutrino spectra of the individual nuclei and the thermal neutrino spectrum (pair+plasma). Results: Although the two considered thermonuclear supernova explosion scenarios are expected to produce almost identical electromagnetic output, their neutrino signatures appear vastly different, which allow an unambiguous identification of the explosion mechanism: a pure deflagration produces a single peak in the neutrino light curve, while the addition of the second maximum characterizes a delayed-detonation. We identified the following main contributors to the neutrino signal: (1) weak electron neutrino emission from electron captures (in particular on the protons Co55 and Ni56) and numerous beta-active nuclei produced by the thermonuclear flame and/or detonation front, (2) electron antineutrinos from positron captures on neutrons, and (3) the thermal emission from pair annihilation. We estimate that a pure deflagration supernova explosion at a distance of 1 kpc would trigger about 14 events in the future 50 kt liquid scintillator detector and some 19 events in a 0.5 Mt water Cherenkov-type detector. Conclusions: While in contrast to core-collapse supernovae neutrinos carry only a very small fraction of the energy produced in the thermonuclear supernova explosion, the SN Ia neutrino signal provides information that allows us to unambiguously distinguish between different possible explosion scenarios. These studies will become feasible with the next generation of proposed neutrino observatories.

  1. Proof testing of an explosion containment vessel

    SciTech Connect

    Esparza, E.D. [Esparza (Edward D.), San Antonio, TX (United States); Stacy, H.; Wackerle, J. [Los Alamos National Lab., NM (United States)

    1996-10-01

    A steel containment vessel was fabricated and proof tested for use by the Los Alamos National Laboratory at their M-9 facility. The HY-100 steel vessel was designed to provide total containment for high explosives tests up to 22 lb (10 kg) of TNT equivalent. The vessel was fabricated from an 11.5-ft diameter cylindrical shell, 1.5 in thick, and 2:1 elliptical ends, 2 in thick. Prior to delivery and acceptance, three types of tests were required for proof testing the vessel: a hydrostatic pressure test, air leak tests, and two full design charge explosion tests. The hydrostatic pressure test provided an initial static check on the capacity of the vessel and functioning of the strain instrumentation. The pneumatic air leak tests were performed before, in between, and after the explosion tests. After three smaller preliminary charge tests, the full design charge weight explosion tests demonstrated that no yielding occurred in the vessel at its rated capacity. The blast pressures generated by the explosions and the dynamic response of the vessel were measured and recorded with 33 strain channels, 4 blast pressure channels, 2 gas pressure channels, and 3 displacement channels. This paper presents an overview of the test program, a short summary of the methodology used to predict the design blast loads, a brief description of the transducer locations and measurement systems, some of the hydrostatic test strain and stress results, examples of the explosion pressure and dynamic strain data, and some comparisons of the measured data with the design loads and stresses on the vessel.

  2. THE BIGGEST EXPLOSIONS IN THE UNIVERSE

    SciTech Connect

    Johnson, Jarrett L.; Whalen, Daniel J.; Smidt, Joseph [Nuclear and Particle Physics, Astrophysics and Cosmology Group (T-2), Thermonuclear Applications Physics Group (XTD-6), Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Even, Wesley; Fryer, Chris L. [Computational Physics and Methods Group (CCS-2), Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Heger, Alex [Monash Centre for Astrophysics, Monash University, VIC 3800 (Australia); Chen, Ke-Jung, E-mail: jlj@lanl.gov [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)

    2013-10-01

    Supermassive primordial stars are expected to form in a small fraction of massive protogalaxies in the early universe, and are generally conceived of as the progenitors of the seeds of supermassive black holes (BHs). Supermassive stars with masses of ?55, 000 M{sub ?}, however, have been found to explode and completely disrupt in a supernova (SN) with an energy of up to ?10{sup 55} erg instead of collapsing to a BH. Such events, ?10, 000 times more energetic than typical SNe today, would be among the biggest explosions in the history of the universe. Here we present a simulation of such a SN in two stages. Using the RAGE radiation hydrodynamics code, we first evolve the explosion from an early stage through the breakout of the shock from the surface of the star until the blast wave has propagated out to several parsecs from the explosion site, which lies deep within an atomic cooling dark matter (DM) halo at z ? 15. Then, using the GADGET cosmological hydrodynamics code, we evolve the explosion out to several kiloparsecs from the explosion site, far into the low-density intergalactic medium. The host DM halo, with a total mass of 4 × 10{sup 7} M{sub ?}, much more massive than typical primordial star-forming halos, is completely evacuated of high-density gas after ?< 10 Myr, although dense metal-enriched gas recollapses into the halo, where it will likely form second-generation stars with metallicities of ? 0.05 Z{sub ?} after ?> 70 Myr. The chemical signature of supermassive star explosions may be found in such long-lived second-generation stars today.

  3. Recovering of components from plastic bonded propellants

    SciTech Connect

    Bohn, M.A.; Schweppe, R. [Fraunhofer-Inst. fuer Chemische Technologie, Pfinztal (Germany)] [Fraunhofer-Inst. fuer Chemische Technologie, Pfinztal (Germany); Weisweiler, W. [Univ. Karlsruhe (Germany). Inst. fuer Chemische Technik] [Univ. Karlsruhe (Germany). Inst. fuer Chemische Technik

    1998-07-01

    Economic reasons and the protection of the environment demand methods of disposal allowing to recover and re-use materials, which have been in service as well as to avoid producing unwanted or harmful substances when doing so. This also applies for propellants and explosives. Recently developed propellants contain expensive crystalline energetic materials such as the nitramines, hexogen (RDX) and octogen (HMX), bonded in a chemical three-dimensional crosslinked polyurethane matrix. These substances are called plastic bonded propellants. In order to recover the components, the polyurethane matrix is broken solvolytically with pure water and alkaline water at temperatures between 130 and 170 C in a pressure cell. From a model rocket propellant, consisting of a polyetherpolyol mixture cured with Desmodur T80 and filled with 60 mass% ammonium perchlorate (AP), 84--90% of the polyetherpolyol component was recovered, and 98% of the AP content subsequently determined in the aqueous solvolysate. The polyetherpolyols were nearly not changed at the high solvolytic stress of 170 C and 2 h, as shown by the molar mass distributions, determined by using gel permeation chromatography. The solid gun propellant KHP consisting of 86 mass% hexogen (RDX) and 14 mass% GAP-N100 binder was solvolyzed at 130, 150 and 170 C with pure water and with 0.05 n NaOH for corresponding time periods of 10, 30 and 60 min. Hexogen is recoverable with high yields and with high purity.

  4. Toxicology of explosives and fireworks in small animals.

    PubMed

    Gahagan, Patti; Wismer, Tina

    2012-03-01

    Intoxication with explosives or fireworks in dogs or cats is not common, but serious toxicosis can result from exposure to different types of explosives depending on the chemical class of explosive involved. This article will discuss the different types of materials/chemicals, clinical signs of toxicosis, and their treatment. Despite the complexities of explosives and plethora of different devices currently in use worldwide, the toxic potential is more easily explained by looking at the relatively short list of chemical classes used to produce these materials. This article combines structurally similar explosives into different groups and focuses on the toxicity of the most commonly available explosives. PMID:22381185

  5. Explosive opening switch work at Westinghouse

    NASA Astrophysics Data System (ADS)

    Aivaliotis, E.; Peterhans, M.

    1989-01-01

    An explosive switch that commutated 315 kA into a resistor and a second version designed to switch up to 1 MA into an HPG (homopolar generator)-driven railgun system are presented. These switches are located very near the load and consist of a set of main busbars in a low-inductance configuration shorted by a thinner switch busbar. Linear-shaped charges are used to sever this switch busbar at several locations when a preselected current level is attained, commutating the current into the load. The feasibility of multishot explosive switches for electromagnetic-launch systems is also considered.

  6. Eutectic composite explosives containing ammonium nitrate

    SciTech Connect

    Stinecipher, M.M.

    1981-01-01

    The eutectic of ammonium nitrate (AN), the ammonium salt of 3,5-dinitro-1,2,4-triazole was prepared and its sensitivity and performance were studied. It was found that this AN formulation was unusual in that it performed ideally at small diameter, which indicated that it was a monomolecular explosive. Sensitivity tests included type 12 impact, Henkin thermal and wedge tests, and performance tests included rate stick/plate dent, cylinder, and aquarium tests. Results were compared with calculations, standard explosives, and another eutectic, ethylendiamine dinitrate (EDD)/AN.

  7. Explosive shaped charge penetration into tuff rock

    SciTech Connect

    Vigil, M.G.

    1988-10-01

    Analysis and data for the use of Explosive Shaped Charges (ESC) to generate holes in tuff rock formation is presented. The ESCs evaluated include Conical Shaped Charges (CSC) and Explosive Formed Projectiles (EFP). The CSCs vary in size from 0.158 to 9.1 inches inside cone diameter. The EFPs were 5.0 inches in diameter. Data for projectile impact angles of 30 and 90 degrees are presented. Analytically predicted depth of penetration data generally compared favorably with experimental data. Predicted depth of penetration versus ESC standoff data and hole profile dimensions in tuff are also presented. 24 refs., 45 figs., 6 tabs.

  8. Lessons learned from a hydrogen explosion

    SciTech Connect

    Neville, A.

    2009-05-15

    On January 8, 2007 a hydrogen explosion at the Msukingum River Power plant's 585-MW coal-fired supercritical unit 5 caused one fatality, injuries to 10 other people and significant damage to several buildings. The explosion occurred during a routine delivery of hydrogen, used to cool generating units, when a hydrogen relief device failed, which allowed the contents of the hydrogen tank to escape and be ignited by an unknown source. This article covers the findings of the incident investigation and the actions the plant has taken to prevent a reoccurrence. 4 photos.

  9. Explosive-driven, high speed, arcless switch

    DOEpatents

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

    1986-05-02

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

  10. Explosive Percolation Transition is Actually Continuous

    NASA Astrophysics Data System (ADS)

    da Costa, R. A.; Dorogovtsev, S. N.; Goltsev, A. V.; Mendes, J. F. F.

    2010-12-01

    Recently a discontinuous percolation transition was reported in a new “explosive percolation” problem for irreversible systems [D. Achlioptas, R. M. D’Souza, and J. Spencer, Science 323, 1453 (2009)SCIEAS0036-807510.1126/science.1167782] in striking contrast to ordinary percolation. We consider a representative model which shows that the explosive percolation transition is actually a continuous, second order phase transition though with a uniquely small critical exponent of the percolation cluster size. We describe the unusual scaling properties of this transition and find its critical exponents and dimensions.

  11. LED pumped polymer laser sensor for explosives

    PubMed Central

    Wang, Yue; Morawska, Paulina O; Kanibolotsky, Alexander L; Skabara, Peter J; Turnbull, Graham A; Samuel, Ifor D W

    2013-01-01

    A very compact explosive vapor sensor is demonstrated based on a distributed feedback polymer laser pumped by a commercial InGaN light-emitting diode. The laser shows a two-stage turn on of the laser emission, for pulsed drive currents above 15.7 A. The ‘double-threshold’ phenomenon is attributed to the slow rise of the ?30 ns duration LED pump pulses. The laser emits a 533 nm pulsed output beam of ?10 ns duration perpendicular to the polymer film. When exposed to nitroaromatic model explosive vapors at ?8 ppb concentration, the laser shows a 46% change in the surface-emitted output under optimized LED excitation.

  12. Tephra from the 1979 soufriere explosive eruption.

    PubMed

    Sigurdsson, H

    1982-06-01

    The explosive phase of the 1979 Soufriere eruption produced 37.5 x 10(6) cubic meters (dense-rock equivalent) of tephra, consisting of about 40 percent juvenile basaltic andesite and 60 percent of a nonjuvenile component derived from the fragmentation of the 1971-1972 lava island during phreatomagmatic explosions. The unusually fine grain size, poor sorting, and bimodality of the land deposit are attributed to particle aggregation and the formation of accretionary lapilli in a wet eruption column. PMID:17808489

  13. Practical small-scale explosive seam welding

    NASA Technical Reports Server (NTRS)

    Bement, L. J.

    1983-01-01

    Joining principles and variables, types of joints, capabilities, and current and potential applications are described for an explosive seam welding process developed at NASA Langley Research Center. Variable small quantities of RDX explosive in a ribbon configuration are used to create narrow (less than 0.5 inch), long length, uniform, hermetrically sealed joints that exhibit parent metal properties in a wide variety of metals, alloys, and combinations. The first major all application of the process is the repair of four nuclear reactors in Canada. Potential applications include pipelines, sealing of vessels, and assembly of large space structures.

  14. Coulomb explosion of a heated cluster

    SciTech Connect

    Novikov, V. N.; Brantov, A. V.; Bychenkov, V. Yu. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation); Kovalev, V. F. [Russian Academy of Sciences, Institute for Mathematical Modeling (Russian Federation)

    2008-11-15

    Coulomb explosion of a charged, nonuniform, and spherically symmetric cluster with a finite ion temperature is investigated. The spatial distributions of the density and mean velocity of accelerated ions, as well as their energy spectra, are obtained and analyzed as functions of the initial temperature. It is shown that taking into account the finite ion temperature eliminates singularities emerging during a Coulomb explosion of a spatially nonuniform cold cluster due to multistream ion motion that arises after breaking the velocity profile of the cluster ions. The characteristic temperature is found above which the spatial distribution and energy spectrum of the expanding ions become regular.

  15. Propagation of a liquid-liquid explosion

    SciTech Connect

    Harlow, F.H.; Ruppel, H.M.

    1981-08-01

    Direct contact between two liquids, one cold and the other hot, may be precluded by the presence of a vapor film. Bridging of this film by one or both fluids results in rapid local boiling, which may initiate a propagating liquid-liquid explosion. A mechanism is discussed for the propagation that involves implosion of the film, rapid mixing of the fluids, heat exchange to warm the cold fluid above the temperature for spontaneous nucleation, and the explosive generation of vapor, which in turn continues to sustain the film implosion. Plausibility for the model is demonstrated by means of numerical studies by high-speed computer.

  16. Producing a computer generated explosive effect

    E-print Network

    Mao, Wei

    1999-01-01

    L N A T U R E OF EXPLOSIONS 7 T U T O R I A L 10 Tutorial Introduction 11 Creating C G Glass 13 Simulating the Explosions 15 Simulating the Debris 28 Special Debris 35 Simulating Glass Debris 36 Creating Smoke 48 Lighting Effects for Glass... Figure 26. Glass group 5 46 Figure 27. Glass group 5 after run dynamics 47 Figure 28. Smoke 48 Figure 29. LightGlass 1 50 Figure 30. LightGlass 2 51 Figure 31. LightGlass 3 52 Figure 32. LightGlass 4 53 Figure 33. LightGlass 5 54 Figure 34. Light...

  17. Pair-Instability Explosions: observational evidence

    E-print Network

    Gal-Yam, Avishay

    2012-01-01

    It has been theoretically predicted many decades ago that extremely massive stars that develop large oxygen cores will become dynamically unstable, due to electron-positron pair production. The collapse of such oxygen cores leads to powerful thermonuclear explosions that unbind the star and can produce, in some cases, many solar masses of radioactive 56Ni. For many years, no examples of this process were observed in nature. Here, I briefly review recent observations of luminous supernovae that likely result from pair-instability explosions, in the nearby and distant Universe.

  18. Detection of hidden explosives by using tagged neutron beams with sub-nanosecond time resolution

    NASA Astrophysics Data System (ADS)

    Pesente, Silvia; Nebbia, Giancarlo; Lunardon, Marcello; Viesti, Giuseppe; Sudac, Davorin; Na?, Karlo; Blagus, Sasha; Valkovi?, Vladivoj

    2004-10-01

    Non-destructive inspection of luggage has been simulated in laboratory conditions by using a 14 MeV tagged neutron beam and BaF 2 scintillation detectors (Tagged Neutron Inspection System, TNIS). The tagged neutron beam is produced by detecting the associated alpha particle emitted in the D+T reaction by means of a YAP:Ce scintillator. The TNIS intrinsic time resolution has been measured to be ? t=0.9 ns [FWHM], which allows inspection of a minimum voxel of 5 cm depth along the neutron flight path. This characteristic is demonstrated by identifying graphite and water samples hidden inside a hard plastic suitcase filled with background material. Finally, explosive devices such as small anti-personnel or anti-tank landmines have been inspected when placed inside the suitcase. In the case of relatively large explosive objects such as an anti-tank landmine, the system is capable of testing directly the TNT charge inside the device, separating this material from the external plastic case. Further developments of the TNIS concept are discussed.

  19. Synaptic plasticity: taming the beast

    Microsoft Academic Search

    Sacha B. Nelson; L. F. Abbott

    2000-01-01

    Synaptic plasticity provides the basis for most models of learning, memory and development in neural circuits. To generate realistic results, synapse-specific Hebbian forms of plasticity, such as long-term potentiation and depression, must be augmented by global processes that regulate overall levels of neuronal and network activity. Regulatory processes are often as important as the more intensively studied Hebbian processes in

  20. Plastics the Second Time Around

    NSDL National Science Digital Library

    2012-11-14

    In this activity, learners test and compare the physical properties of thermoplastic polymers. Learners compare different plastics based on their color, degree of transparency, texture, and density. Use this activity to discuss why some plastics can be recycled and others cannot. Safety note: Educators should read the "General Safety Guidelines."