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1

27 CFR 555.181 - Reporting of plastic explosives.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Reporting of plastic explosives. 555.181 Section 555.181...EXPLOSIVES COMMERCE IN EXPLOSIVES Marking of Plastic Explosives § 555.181 Reporting of plastic explosives. All persons, other...

2013-04-01

2

27 CFR 555.181 - Reporting of plastic explosives.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Reporting of plastic explosives. 555.181 Section 555.181...EXPLOSIVES COMMERCE IN EXPLOSIVES Marking of Plastic Explosives § 555.181 Reporting of plastic explosives. All persons, other...

2009-04-01

3

Fluorine analysis of plastic-bonded explosives and plastics  

Microsoft Academic Search

A method for the analysis of 25 to 200 mg of fluorine in highly fluorinated plastics and plastic-bonded explosives is presented. Up to 1 g of the explosive is burned by the oxygen bomb technique. The polymers are burned with an excess of paraffin fuel. After removal of carbon dioxide from the combustion products, fluorine is determined gravimetrically as lithium

Walter Selig

1968-01-01

4

Thermal stability of a plastic bonded explosive  

Microsoft Academic Search

Data on the thermal stability of a plastic bonded explosive containing an oxidizer cyclotetramethylene tetranitramine (HMX), binder and plasticizer was required in order to satisfy the requirement of NAVORD OD 44811 and to obtain safety information for handling and use. The thermal stability of the PBX was determined by dynamic differential scanning calorimetry (DSC) in sealed\\/unsealed sample pans and by

Albert S Tompa; Robert F Boswell

2000-01-01

5

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

Code of Federal Regulations, 2013 CFR

... 2013-04-01 false Importation of plastic explosives on or after April 24, 1997...EXPLOSIVES COMMERCE IN EXPLOSIVES Marking of Plastic Explosives § 555.183 Importation of plastic explosives on or after April 24,...

2013-04-01

6

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

Code of Federal Regulations, 2010 CFR

... 2010-04-01 false Importation of plastic explosives on or after April 24, 1997...EXPLOSIVES COMMERCE IN EXPLOSIVES Marking of Plastic Explosives § 555.183 Importation of plastic explosives on or after April 24,...

2010-04-01

7

Plane Shock Initiation of an RDX Plastic-Bonded Explosive  

Microsoft Academic Search

The plane-wave shock initiation of a plastic-bonded RDX explosive, initial density 1.60 g?cc, has been investigated by measurement of shock buildup to detonation using the explosive wedge technique. Impedance-match techniques were employed to determine the pressure and particle velocity associated with the shock in the explosive. Using a graphical representation in which the shock distance and time coordinates are referred

I. E. Lindstrom

1966-01-01

8

Behavior of Plastic Bonded Composite Explosives During High Acceleration  

NASA Astrophysics Data System (ADS)

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

Lanzerotti, Y.

1998-03-01

9

Aktau Plastics Plant Explosives Material Report  

SciTech Connect

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.

CASE JR.,ROGER S.

1999-12-01

10

Microstructural characterization of simulated plastic-bonded explosives  

NASA Astrophysics Data System (ADS)

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

Yeager, John David

11

Dynamic Fracture Behavior of Plastic-Bonded Explosives  

NASA Astrophysics Data System (ADS)

Plastic-Bonded Explosives (PBX) are used as important energetic materials in nuclear or conventional weapons. Arms Warhead in the service process and the ballistic phase, may experience complex process such as long pulse and higher loading , compresson, tension and reciprocating compression - tension, friction with the projectile shell, which would lead to explosive deformation and fracture.And the dynamic deformation and fracture behavior of PBX subsequently affect reaction characteristics and initiation mechanism in explosives, then having influence on explosives safety. The dynamic fracure behavior of PBX are generally complex and not well studied or understood. In this paper, the dynamic fracture of explosives are conducted using a Kolsky bar.The Brazilian test, also known as a indirect tensile test or splitting test , is chosen as the test method. Tensile strength under different strain rates are obtained using quartz crystal embedded in rod end. The dynamic deformation and fracture process are captured in real-time by high-speed digital camera, and the displacement and strain fields distribution before specimen fracture are obtained by digital correlation method. Considering the non-uniform microstructure of explosives,the dynamic fracture behavior of explosive are simulated by discrete element method, the simulation results can reproduce the deformation and fracture process in Brazilian test using a maximum tensile strain criterion.

Fu, Hua; Li, Jun-Ling; Tan, Duo-Wang

2011-06-01

12

Thermal analyses for quality control of plastics, ceramics, and explosives  

SciTech Connect

Thermal analyses are performed for production quality control (q.c.) and for surveillance at Mound on plastic, ceramic, explosive and pyrotechnic materials. For the weapons surveillance program, weapon components are disassembled after varying times in the field; thermal and other analyses are then performed on the component materials. The types of thermal analyses done include: differential scanning calorimetry (DSC), differential thermal analysis (DTA), thermogravimetry (TG), thermomechanical analysis (TMA), and high temperature TG/DTA. 5 refs., 4 figs.

Brown, C.R.; Garrod, M.J.; Whitaker, R.B.

1990-01-01

13

Detection and characterization of long-pulse low-velocity impact damage in plastic bonded explosives  

Microsoft Academic Search

Damage not only degrades the mechanical properties of explosives, but also influences the shock sensitivity, combustion and even detonation behavior of explosives. The study of impact damage is crucial in the vulnerability evaluation of explosives. A long-pulse low-velocity gas gun with a gas buffer was developed and used to induce impact damage in a hot pressed plastic bonded explosive. Various

Pengwan Chen; Fenglei Huang; Kaida Dai; Yansheng Ding

2005-01-01

14

Release isentropes of overdriven plastic-bonded explosive PBX-9501  

NASA Astrophysics Data System (ADS)

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 are presented. Because isentropes from different overdriven states differ, a crude estimate of the Grneisen parameter is obtained. An overall representation of the data is achieved with this Grneisen parameter and a single isentrope through the Chapman-Jouguet state.

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

2000-12-01

15

Numerical simulation of the plastic flow field near the bonding surface of explosive welding  

Microsoft Academic Search

Numerical simulation on the plastic flow near the bonding surface of explosive welding is executed under some limited conditions. In order to calculate the bonding interface generation in explosive welding, a second order finite difference method is developed for elasticplastic material. In this simulation the formation process of bonding interface deformation generated by a symmetric collision between copper plates is

Akihisa Abe

1999-01-01

16

Detonation Wave Profiles in Plastic Bonded Explosives Measured using 1550 nm Heterodyne Velocimetry  

Microsoft Academic Search

We have measured detonation wave profiles in several triaminotrinitrobenzene (TATB) and cyclotetramethylene tetranitramine (HMX or octogen) based plastic bonded explosives using 1550 nm Heterodyne Velocimetry. (Heterodyne Velocimetry is also called Photon Doppler Velocimetry or PDV.) Planar detonations were produced by impacting the explosive with projectiles launched in a gas gun. Particle velocity wave profiles were measured at the mirror\\/interface of

Rick Gustavsen

2009-01-01

17

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

Microsoft Academic Search

The confinement experienced by an explosive during thermal self-initiation can substantially affect performance in terms of deflagrationtodetonation 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

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

2005-01-01

18

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

Microsoft Academic Search

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

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

2005-01-01

19

Detection of plastic explosives in luggage with 14 N nuclear quadrupole resonance spectroscopy  

Microsoft Academic Search

Nuclear quadrupole resonance (NQR) of14N nuclei has many advantages as a method for detecting nitrogen-containing explosives, the most important are very high chemical\\u000a specificity, true noninvasive operation and detection of bulk explosive in situ only (no vapor or particular capture needed).\\u000a One of the most high explosives is hexogen (RDX) often used by terrorists in plasticized forms. The ring nitrogen

M. Ostafin; B. Nogaj

2000-01-01

20

The Hugoniot and shock sensitivity of a plastic-bonded TATB explosive PBX 9502  

Microsoft Academic Search

The plane shock response of PBX 9502 was measured from 0.5 to 25 GPa. The explosive is 95-wt. % triamino-trinitrobenzene powder coated with Kel-F 800 plastic; porosity was 2.6%. Shock initiation sensitivity, the Hugoniot, and dynamic yield behavior were studied. Experiments done were explosively driven wedge tests and particle velocity history measurements using electromagnetic gauges at a light-gas gun. A

J. J. Dick; C. A. Forest; J. B. Ramsay; W. L. Seitz

1988-01-01

21

Reactive flow lagrange analysis in plastic bonded explosives  

Microsoft Academic Search

A description of Lagrange gauge measurements in PBX-9404 and RX-26-AF is given. The data are used to study the progress of reaction in these explosives. The results are discussed along with the underlying theortetical assumptions. Emphasis is given to the practical problems of constructing a description of the chemical reaction from gauge data.

Gerald L. Nutt; Leroy M. Erickson

1984-01-01

22

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

SciTech Connect

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.

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

23

The relationship between plastic deformation and collision angle in explosive welding  

Microsoft Academic Search

In explosive welding, as in other methods of welding metals by pressure, the joint is formed by simultaneous plastic deformation of the contacting surfaces, the value of which determines the final properties of the joint [i]. The collision regime of the welded plates can be specified by three basic kinematic parameters: the velocity of the driven plate v 0, the

V. A. Simonov

1991-01-01

24

Damage and fracture prediction of plastic-bonded explosive by digital image correlation processing  

Microsoft Academic Search

By digital correlation processing of Scanning electronic microscopy (SEM) images, the paper presents the deformation and damage analysis of an energetic materialthe plastic-bonded explosive (PBX) on mesoscopic scale. The analysis is made by observing the deformation field resulted from the digital image correlation (DIC) processing of the images corresponding to the loading steps and comparing with the surface profiles of

M. Li; J. Zhang; C. Y. Xiong; J. Fang; J. M Li; Y. Hao

2005-01-01

25

Characterization of the viscoelastic behaviour of a plastic-bonded explosive  

Microsoft Academic Search

An experimental study of the viscoelastic behaviour of a composite explosive material with an octogen content of almost 95% is presented. The addition of a plastic binder results in a material that, following isostatic compaction, exhibits a quasi-brittle behaviour that is strongly dependent on the strain rate. Some mechanical spectrometry tests were carried out in order to characterise this behaviour.

D. Picart; J. L. Brigolle

2010-01-01

26

Dynamic strength of cylindrical fiber-glass shells and basalt plastic shells under multiple explosive loading  

NASA Astrophysics Data System (ADS)

We have shown experimentally that, for cylindrical shells made of oriented fiberglass platic and basalt plastic there exists a critical level of deformations, at which a structure sustains a given number of explosions from the inside. The magnitude of critical deformation for cylindrical fiberglass shells depends linearly on the logarithm of the number of loads that cause failure. For a given type of fiberglass, there is a limiting level of explosive action, at which the number of loads that do not lead to failure can be sufficiently large (more than 102). This level is attained under loads, which are an order of magnitude lower than the limiting loads under a single explosive action. Basalt plastic shells can be repeatedly used even at the loads, which cause deformation by 30-50% lower than the safe value 3.3.5% at single loading.

Syrunin, M. A.; Fedorenko, A. G.

2006-08-01

27

Coupled phase transformation, chemical decomposition, and deformation in plastic-bonded explosive: Models  

Microsoft Academic Search

A continuum thermomechanochemical model of the behavior of a plastic-bonded explosive (PBX) 9501 formulation consisting of the energetic crystal octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) embedded in a polymeric binder is developed. Our main focus is on the study of the betadelta phase transformations (PTs) in crystalline HMX under a complex pressure-temperature path. To reproduce the pressure-temperature path, in particular during heating of PBX

Valery I. Levitas; Bryan F. Henson; Laura B. Smilowitz; David K. Zerkle; Blaine W. Asay

2007-01-01

28

Coupled phase transformation, chemical decomposition, and deformation in plastic-bonded explosive: Models  

Microsoft Academic Search

A continuum thermomechanochemical model of the behavior of a plastic-bonded explosive (PBX) 9501 formulation consisting of the energetic crystal octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) embedded in a polymeric binder is developed. Our main focus is on the study of the ??? phase transformations (PTs) in crystalline HMX under a complex pressure-temperature path. To reproduce the pressure-temperature path, in particular during heating of PBX

Valery I. Levitas; Bryan F. Henson; Laura B. Smilowitz; David K. Zerkle; Blaine W. Asay

2007-01-01

29

Molecular dynamics simulations of RDX and RDX-based plastic-bonded explosives  

Microsoft Academic Search

Molecular dynamics simulations have been performed to investigate well-known energetic material cyclotrimethylene trinitramine (RDX) crystal and RDX-based plastic-bonded explosives (PBXs) with four typical fluorine-polymers, polyvinylidenedifluoride (PVDF), polychlorotri-fluoroethylene (PCTFE), fluorine rubber (F2311), and fluorine resin (F2314). The elastic coefficients, mechanical properties, binding energies, and detonation performances are obtained for the RDX crystal and RDX-based PBXs. The results indicate that the mechanical

Wei Zhu; Jijun Xiao; Weihua Zhu; Heming Xiao

2009-01-01

30

Creep Testing Plastic-Bonded Explosives in Uni-axial Compression  

SciTech Connect

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.

Gagliardi, F J; Cunningham, B J

2008-03-13

31

Study of initiation reactivity of some plastic explosives by vacuum stability test and non-isothermal differential thermal analysis  

Microsoft Academic Search

On the basis of measurements of 18 high explosives by means of the Czech Vacuum Stability Test (VST) STABIL, a relationship has been specified between the results of this test and those of Russian manometric method. The said relationship was used to predict the Arrhenius parameters (Ea and logA values) of four plastic explosives based on RDX and one high

Martina Chovancov; Svatopluk Zeman

2007-01-01

32

Detonation Wave Profiles in Plastic Bonded Explosives Measured using 1550 nm Heterodyne Velocimetry  

NASA Astrophysics Data System (ADS)

We have measured detonation wave profiles in several triaminotrinitrobenzene (TATB) and cyclotetramethylene tetranitramine (HMX or octogen) based plastic bonded explosives using 1550 nm Heterodyne Velocimetry. (Heterodyne Velocimetry is also called Photon Doppler Velocimetry or PDV.) Planar detonations were produced by impacting the explosive with projectiles launched in a gas gun. Particle velocity wave profiles were measured at the mirror/interface of the explosive and either a LiF or PMMA window. Mirrors consisted of either a thin vapor deposited aluminum layer, or a 6 micron thick aluminum foil. Focusing and collimating light collection probes were used. Time-Frequency-Analysis of the fringe data was carried out using both Wavelet and Short-Time-Fourier-Transform (STFT) methods. With clean fringe data, good profiles can be obtained with a 1 ns full width half maximum (FWHM) analysis window (STFT) or about 3 to 4 oscillations in the wavelet. Some profiles, however, have a noisy character which is correlated with intensity fluctuations in the raw fringe data. Wave profiles show a ZND reaction zone structure with a single reaction in the HMX based explosives and both fast and slow reactions in the TATB based explosives.

Gustavsen, Rick

2009-06-01

33

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

SciTech Connect

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.

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

34

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

SciTech Connect

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

Hoffman, D M; Chandler, J B

2004-07-08

35

Efficient construction of unmarked recombinant mycobacteria using an improved system.  

PubMed

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

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

2014-08-01

36

Aspects of the Tribology of the Plastic Bonded Explosive (PBX) 9404  

SciTech Connect

The coefficient of friction, {mu}, of the plastic bonded explosive (PBX) 9404 was measured on stainless steel, aluminum, Teflon and the explosive itself as a function of temperature between ambient and 135 C at a rotational speed of 0.0025 rad/sec{sup -1}. An optical profilometer was used to analyze the mean surface roughness, R{sub a}, of the various materials. PBX 9404 is a composite of the explosive 1,3,5,7-tetranitroazacyclooctane (HMX) chloroethyl phosphate (CEF) and nitrocellulose in an 96/3/3 weight ratio. The average roughness of the pressed explosive surface was R{sub a} = 1.37 {micro}m. The coefficient of friction for PBX 9404 on stainless steel of R{sub a} = 0.40 {micro}m increased from 0.22 at ambient to 0.34 at 95 C. Above this temperature {mu} decreased to about 0.23 at 125 C. Similar behavior was observed with aluminum with R{sub a} = 0.31 {micro}m. The coefficient of friction increased from about 0.08 at ambient to 0.48 at 115 C. Above this temperature, {mu} tended to decrease slightly. The coefficient of friction against Teflon of R{sub a} = 0.054 {micro}m was sigmoidal, increasing from about 0.3 at ambient to about at 0.49 {+-} 0.002 above 115 C. Against a PBX 9404 counter surface, the coefficient of friction averaged 0.54 over the entire test temperature range, but tended to increase during the measurement, probably due to adhesion of the nitrocellulose to itself.

Hoffman, D M; Chandler, J B

2004-07-08

37

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

SciTech Connect

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

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

1985-01-01

38

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

SciTech Connect

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

Thompson, Darla Graff [Los Alamos National Laboratory; Brown, Geoff W [Los Alamos National Laboratory; Deluca, Racci [Los Alamos National Laboratory; Giambra, Anna [Los Alamos National Laboratory; Sandstrom, Mary [Los Alamos National Laboratory

2009-01-01

39

Effects of temperature and pressure on the glass transitions of plastic bonded explosives  

SciTech Connect

Various plastic bonded explosives (PBXs) contain about 5-wt% polymer, plasticizer, and stabilizer as binder. The glass-transition temperature (T{sub g}) determines, in part, if the binder will reduce or increase the sensitivity of the PBX to impact. A soft binder reduces the impact sensitivity; however, too soft a binder compromises the mechanical strength below that desirable for dimensional stability. Glass transitions were measured by temperature modulated DSC for PBXs before and after pressing. Pressing temperature was 90 C. The T{sub g} of Estane, a polyester/polyurethane used in some PBX binders, was investigated. Only small changes were observed in the low temperature T{sub g} of the soft segments but larger changes were seen in the higher temperature transitions due to the relaxation of the hard segments. The T{sub g} of Kel F 800, a binder used in insensitive PBX 9502, was observed near ambient temperature. The PBX 9502 had a lower T{sub g} than the neat polymer. Mechanical strength will be measured for the samples.

Campbell, M.S.; Garcia, D.; Idar, D.

1998-12-31

40

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

NASA Astrophysics Data System (ADS)

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

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

2012-05-01

41

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

PubMed

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

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

2010-04-01

42

Large-scale ODTX standard test. Process development endeavor No. 301. [Thermal stability of plastic-bonded explosives  

SciTech Connect

A standard ODTX test configuration was designed and proven for 12.7 mm dia. x 50.8 mm long and 25.4 mm dia. x 76.2 mm long test samples. The results from plastic-bonded explosives (LX-10, PBX 9501, X-0298, PBX 9502, RX-26-AF and PBX 9502) suggest a shortened sample and larger heater contributed to achieving a near isothermal test environment. The ODTX test is used to establish safe pressing temperatures for large explosive parts.

Schmitz, G.T.; Faubion, B.D.

1982-08-01

43

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

SciTech Connect

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.

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

44

Large-scale ODTX standard test. Process development endeavor No. 301. [Thermal stability of plastic-bonded explosives  

Microsoft Academic Search

A standard ODTX test configuration was designed and proven for 12.7 mm dia. x 50.8 mm long and 25.4 mm dia. x 76.2 mm long test samples. The results from plastic-bonded explosives (LX-10, PBX 9501, X-0298, PBX 9502, RX-26-AF and PBX 9502) suggest a shortened sample and larger heater contributed to achieving a near isothermal test environment. The ODTX test

G. T. Schmitz; B. D. Faubion

1982-01-01

45

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

NASA Astrophysics Data System (ADS)

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

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

2013-08-01

46

Inference about density and temporary emigration in unmarked populations  

USGS Publications Warehouse

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

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

2011-01-01

47

Meso-scale Origins of the Low- Pressure Equation of State and High Rate Mechanical Properties of Plastic Bonded Explosives  

NASA Astrophysics Data System (ADS)

Most modern high explosives are formulated from a selection of energetic crystalline materials and plastics to create a material that accommodates the performance and sensitivity characteristic of the desired application.1 These materials are exposed to a variety of thermal-mechanical loads during their service life. Recent interest has focused research on safety and survivability under conditions that produce long duration low amplitude loads. The interest is on ignition of deflagration rather than intiation of detonation. A fully coupled thermal-mechanical/ chemical kinetic representation of the problem is contained in a modified form of the Frank-Kamenetskii eqautions.2 Experimental techniques have been developed to characterize the low-pressure equation of state 3 and the high-rate mechanical behavior of a representative material.4 Samples recovered from these experiments have been subjected to expensive microscopic analysis using optical and scanning electron microscopy. These data illustrate the presence of stress chains and stress bridging among the high explosive particle embedded in the polymer. The mechanical properties of the explosive crystal are quite different from those of the polymer. Significant inelastic response of the explosive crystal is apparent even in specimens which appear to have under gone only elastic deformation. The explosive crystals are clearly cleaved during the collapse of the stress bridges during the apparent elastic response of the bulk material. 1. LASL Shock Hugoniot Data, ed. Stanley P.Marsh, University of California Press. ISBN 0-520-04008-2, 1080 2. Foster, Jr., J. C., Christopher, F. R., Wilson, L. L., Osborn, J., "Mechanical Ignition Of Combustion In Condensed Phase High Explosives," presented at the APS Topical Conference on Shock Compression of Condensed Matter, Amherst, MA, August, 1997. 3.Foster, Jr. Joseph C., Low Pressure Equation of State Measurements of Explosives using Piston Test Techniques, ," presented at the APS Topical Conference on Shock Compression of Condensed Matter, Amherst, MA, August, 1997. 4. Christopher, F. R., Foster, Jr., J. C., Wilson, L. L, Gilland, H. "The Use Of Impact Techniques To Characterize The High Rate Mechanical Properties Of Plastic Bonded Explosive," 11th International Detonation Symposium, Snowmass CO, 1998

Foster, Joseph C., Jr.; Glenn, Joseph G.; Gunger, Mike

1999-06-01

48

Investigation of the Effect of Binder Crystallinity on the Mechanical Properties of a Plastic Bonded Explosive. Period Covered: October--December 1976.  

National Technical Information Service (NTIS)

The tensile properties of a plastic bonded explosive RX-03-BB were investigated as a function of the degree of crystallinity of the plastic binder. This investigation was to determine if stress/strain properties of RX-03-BB would be affected by an increas...

L. C. Myers H. D. Johnson

1976-01-01

49

The Role of Localized Plastic Flow in the Impact Initiation of Explosives  

Microsoft Academic Search

Individual crystals of silver and lead azide have been impacted by spherical particles. Impact was at normal incidence on flat faces of the explosives. A novel feature of the experiment was that the particles were very small compared with the millimetre dimension crystals. This meant that the impact damage was independent of the shape of the explosive. Initiation took place

R. E. Winter; J. E. Field

1975-01-01

50

Shock-wave sensitivity of a TATB-based plasticized explosive  

Microsoft Academic Search

The results of numerical modelling of experiments on the investigation of shock-wave sensitivity of a TATB-based explosive are presented. A model for the macrokinetics of decomposition of the explosive has been constructed within the framework of a hypothesis of hot spots.

Yu. A. Aminov; A. V. Vershinin; O. V. Kostitsyn; B. G. Loboiko; V. S. Lyubimov; S. N. Lyubyatinskii; G. N. Rykovanov; M. A. Strizhenok

1995-01-01

51

Coupled phase transformation, chemical decomposition, and deformation in plastic-bonded explosive: Models  

NASA Astrophysics Data System (ADS)

A continuum thermomechanochemical model of the behavior of a plastic-bonded explosive (PBX) 9501 formulation consisting of the energetic crystal octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) embedded in a polymeric binder is developed. Our main focus is on the study of the ?<-->? phase transformations (PTs) in crystalline HMX under a complex pressure-temperature path. To reproduce the pressure-temperature path, in particular during heating of PBX inside of a rigid cylinder, the ?<-->? PTs in HMX are coupled to chemical decomposition of the HMX and binder leading to gas formation, gas leaking from the cylinder, elastic, thermal, and transformational straining as well as straining due to mass loss. A fully physically based thermodynamic and kinetic model of the ?<-->? PT in HMX crystal is developed. It is based on a suggested nucleation mechanism via melt mediated nanocluster transformation and the recently revealed growth mechanism via internal stress-induced virtual melting. During the nucleation, nanosize clusters of the ? phase dissolve in a molten binder and transform diffusionally into ? phase clusters. During the interface propagation, internal stresses induced by transformation strain cause the melting of the stressed ? phase much below (120 K) the melting temperature and its immediate resolidification into the unstressed ? phase. These mechanisms explain numerous puzzles of HMX polymorphism and result in overall transformation kinetics that is in good agreement with experiments. Simple phenomenological equations for kinetics of chemical decomposition of the HMX and the binder are in good correspondence with experiments as well. A continuum deformation model is developed in two steps. The geometrically linear (small strain) theory is used to prove that the internal stresses and macroscopic shear stresses are negligible. Then a large strain theory is developed under hydrostatic loading. The developed continuum thermomechanochemical model is applied in the accompanying paper [V. I. Levitas, B. F. Henson, L. B. Smilowitz, D. K. Zerkle, and B. W. Asay, J. Appl. Phys. (submitted)] to modeling the heating of PBX inside of a rigid cylinder.

Levitas, Valery I.; Henson, Bryan F.; Smilowitz, Laura B.; Zerkle, David K.; Asay, Blaine W.

2007-12-01

52

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

NASA Astrophysics Data System (ADS)

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 process. This study applies an image analysis tool to measure particle size distributions (PSDs) during the slurry process to produce PBX 9501, a specific formulation used in nuclear weapons. The observed PBX 9501 slurry behavior leads away from the typical population balance description of agglomeration, that is, a discrete particle-particle coalescence mechanism. The behavior observed in these experiments indicates that the initial state of the system contains a number of smaller particles clustered together. The cluster then coalesces into a large particle as solvent is removed and the slurry continuously mixed. Other small fragments are picked up and a relatively small amount of growth is observed. A mass transfer model adequately describes solvent removal, and an empirical model is developed to describe the growth behavior in terms of measured process variables. The image system is applied to dried molding powders. The PSD measurement results of the PBX 9501 library lots, historic samples set aside as PBX 9501 lots were accepted from the manufacturer, are also discussed and analyzed. A correlation analysis was conducted to find relationships between the measured PSD and other properties such as bulk density and pressed densities. While no significant correlation was found between the measured PSD and averaged bulk densities for the library lots, significant correlations are found between the measured PSD and pressed density. The final part of the study was to scale-up the PSD measurement capability. Since the large-scale processes are not yet operational, this work makes recommendations for future consideration. Also, some additional small-scale experiments are recommended as well as improvements to the small-scale experimental apparatus.* *This dissertation is a compound document (contains both a paper copy and a CD as part of the dissertation). The CD requires the following system requirements: Adobe Acrobat.

Sullivan, Gregg Kent

53

Platform loading from explosions in saturated sand using avisco-plastic model  

Microsoft Academic Search

A set of experiments were conducted at the Aberdeen Proving Grounds 1 (Taylor, L.C., Skaggs, R.R. and Gault, W., 2005. Vertical impulse measurements of mines buried in saturated sand. Proceedings of the 31st Annual Conference on Explosives and Blasting Technique, Orlando, FL, 69 February, 2.) in which explosive charges were buried in saturated sand beneath a suspended rigid platform. The

W. G. Szymczak

2005-01-01

54

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

SciTech Connect

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.

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

55

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

Microsoft Academic Search

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

Reaugh

2009-01-01

56

Investigation of the Elastic-Plastic Behavior of Explosively Actuated Valves.  

National Technical Information Service (NTIS)

MAVIS is a computer program for the modeling and analysis of explosive valves. Until recently, the drag forces between the plunger and the housing have been calculated by modeling the valve as a series of thin disks, then assuming an elastic interference ...

A. F. Emery B. K. Jones M. F. Hardwick R. Ng

1988-01-01

57

Explosive Safety Container.  

National Technical Information Service (NTIS)

The container is in the form of a plastic block with a hole for containing an explosive. The plastic is loaded into a tubular vessel such as glass or polyethylene. The plastic block is made of a plastic material which does not shatter like metal.

M. F. T. Zimmer L. K. Asaoka

1965-01-01

58

Scaling of light emission from detonating bare Composition B, 2,4,6-trinitrotoluene [C7H5(NO2)3], and PE4 plastic explosive charges  

NASA Astrophysics Data System (ADS)

It is well known that an intense flash of light is emitted when an explosive charge is detonated. The light emission continues well beyond the actual detonation process due to shock excitation of the air molecules around the charge, as well as post-detonation reactions in the expanding products of the detonation. Various researchers have studied these emissions, and it has been established that there are features in such emission spectra that can be regarded as characteristic for a specific explosive composition and configuration. In this study, the emission characteristics at wavelengths between 650 and 940 nm were experimentally investigated for cylindrical bare Composition B, 2,4,6-trinitrotoluene [C7H5(NO2)3], and PE4 plastic explosive charges in the mass (M) range of 0.5 kg to 4 kg. The results show that the light emission parameters scale to M1/3 consistent with other explosive blast parameters such as pressure and impulse (so-called Hopkinson's scaling). It is also shown that for bare charges, two distinct regions in time can be distinguished for the light emission, namely, light from the early time frame, while the charge is detonating (and slightly beyond), and light from the expanding products of the explosive (the ``fireball''). It is argued that in the first region, ionization effects and shock excitation of the air molecules around the charge dominate the light emission. The dominance of these effects fizzles out rapidly as the blast wave expands from the charge, leaving only light emission from the expanding products of the detonation.

Mostert, Frederik J.; Olivier, Marius

2011-10-01

59

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

USGS Publications Warehouse

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.

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

60

The Use of a High Frequency Film Camera to Study Plastic Deformation of Metals at Explosive Burdens.  

National Technical Information Service (NTIS)

A method is described of using the Czech high frequency film camera for the purpose of registering the process of explosive deformation of metals. The main attention is devoted to the method of illuminating the filmed action and synchronization of the for...

A. Schweighofer

1966-01-01

61

Resolving Mechanical Response of Plastic Bonded Explosives at High Strain-Rate Using Split Hopkinson Pressure Bar  

Microsoft Academic Search

The mechanical properties of two explosives (PBXN-110 and PBXW-128) were determined using a split-Hopkinson pressure bar at strain rates between 103 \\/s and 104 \\/s. The stress-strain data for 1, 2 and 3-wave analysis were compared to determine when stress equalization was achieved in the test samples. PBXN-110 behaved similar to conventional Hopkinson bar samples, i.e., stress equalization was maintained

Vasant S. Joshi; Richard J. Lee

2002-01-01

62

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

PubMed

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

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

2014-07-01

63

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

USGS Publications Warehouse

Recently developed spatial capturerecapture (SCR) models represent a major advance over traditional capturerecapture (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 510% 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: 0.191.64) 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 densityrather, spatial dependence can be informative about individual distribution and density.

Chandler, Richard B.; Royle, J. Andrew

2013-01-01

64

Introduction of Unmarked Mutations in theHelicobacter pylori vacA Gene with a Sucrose Sensitivity Marker  

Microsoft Academic Search

Research onHelicobacter pylorihas been hindered by the lack of useful genetic tools. Using thesacBgene of Bacillus subtilis, we developed a sucrose-based counterselection system that allows introduction of unmarked mutations inH. pylori.Akan-sacBcassette, consisting of thesacBgene expressed from theH. pyloriflagellin promoterandthekanamycinresistancemodule,wasintroducedbyhomologousrecombinationintoatargetH. pylori gene. The resultant strains were sucrose sensitive and kanamycin resistant. Following transformation with a mutated allele, growth in sucrose-containing medium

MICHAEL COPASS; GUIDO GRANDI; ANDRINO RAPPUOLI

1997-01-01

65

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

PubMed Central

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.

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

2009-01-01

66

Hazard Characterization of Explosives by Use of the Friction Sensitivity Test.  

National Technical Information Service (NTIS)

Friction tests were conducted on a variety of explosives materials: pure liquids and solids, pastes, extrusion cast explosives, and plastic bonded explosives. The response of explosives to friction, especially for new formulations, is an important handlin...

G. L. Moody

1987-01-01

67

A new simple method for introducing an unmarked mutation into a large gene of non-competent Gram-negative bacteria by FLP/FRT recombination  

PubMed Central

Background For the disruption of a target gene in molecular microbiology, unmarked mutagenesis is preferable to marked mutagenesis because the former method raises no concern about the polar effect and leaves no selection marker. In contrast to naturally competent bacteria, there is no useful method for introducing an unmarked mutation into a large gene of non-competent bacteria. Nevertheless, large genes encoding huge proteins exist in diverse bacteria and are interesting and important for physiology and potential applications. Here we present a new method for introducing an unmarked mutation into such large genes of non-competent Gram-negative bacteria. Results Two gene replacement plasmids, pJQFRT and pKFRT/FLP, were constructed to apply the FLP/FRT recombination system to introduce an unmarked mutation into a large gene of non-competent Gram-negative bacteria. In our methodology, pJQFRT and pKFRT/FLP are integrated into the upstream and the downstream regions of a target gene, respectively, through homologous recombination. The resultant mutant has antibiotic resistance markers, the sacB counter-selection marker, flp recombinase under the control of the tetR regulator, and identical FRT sites sandwiching the target gene and the markers on its chromosome. By inducing the expression of flp recombinase, the target gene is completely deleted together with the other genes derived from the integrated plasmids, resulting in the generation of an unmarked mutation. By this method, we constructed an unmarked mutant of ataA, which encodes the huge trimeric autotransporter adhesin (3,630 aa), in a non-competent Gram-negative bacterium, Acinetobacter sp. Tol 5. The unmarked ataA mutant showed the same growth rate as wild type Tol 5, but lost the adhesive properties of Tol 5, similar to the transposon-inserted mutant of ataA that we generated previously. Conclusions The feasibility of our methodology was evidenced by the construction of an unmarked ataA mutant in the Tol 5 strain. Since FLP/FRT recombination can excise a long region of DNA exceeding 100?kb, our method has the potential to selectively disrupt much larger genes or longer regions of gene clusters than ataA. Our methodology allows the straightforward and efficient introduction of an unmarked mutation into a large gene or gene cluster of non-enterobacterial Gram-negative bacteria.

2013-01-01

68

Training Dogs for Explosives Detection.  

National Technical Information Service (NTIS)

A feasibility study was undertaken to determine whether dogs can be trained to discriminate the odor of commercial dynamite (straight nitroglycerin dynamite and ammonium nitrate dynamite), black powder and the plastic explosives, C3 and C4. Initial discri...

R. C. Phillips

1971-01-01

69

Explosive Welding.  

National Technical Information Service (NTIS)

Explosive welding occurs when adjacent surfaces of appropriately positioned metals are properly thrust together by energy released from an explosive source. The procedure consists essentially of locating the metal members being welded between an explosive...

H. J. Addison

1964-01-01

70

Detonation wave profiles in HMX based explosives  

NASA Astrophysics Data System (ADS)

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.

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

1998-07-01

71

Detonation wave profiles in HMX based explosives  

SciTech Connect

Detonation wave profiles have been measured in several HMX based plastic bonded explosives including PBX9404, PBX9501, and EDC-37, as well as two HMX powders (coarse and fine) pressed to 65% of crystal density. The powders had 120 and 10 {micro}m average grain sizes, respectively. Planar detonations were produced by impacting the explosive with projectiles launched in a 72-mm bore gas gun. Impactors, impact velocity, and explosive thickness were chosen so that the run distance to detonation was always less than half the explosive thickness. For the high density plastic bonded explosives, particle velocity wave profiles were measured at an explosive/window interface using two VISAR interferometers. PMMA windows with vapor deposited aluminum mirrors were used for all experiments. Wave profiles for the powdered explosives were measured using magnetic particle velocity gauges. Estimates of the reaction zone parameters were obtained from the profiles using Hugoniots of the explosive and window.

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

1997-11-01

72

27 CFR 555.26 - Prohibited shipment, transportation, receipt, possession, or distribution of explosive materials.  

Code of Federal Regulations, 2013 CFR

...possession, or receipt of explosive materials is in furtherance...receipt, or possession of the explosive materials is in furtherance...or possession of plastic explosives that do not contain a detection agent. [ATF No....

2013-04-01

73

Animating explosions  

Microsoft Academic Search

In this paper, we introduce techniques for animating explosions and their effects. The primary effect of an explosion is a disturbance that causes a shock wave to propagate through the surrounding medium. The disturbance determines the behavior of nearly all other secondary effects seen in explosion. We simulate the propagation of an explosion through the surrounding air using a computational

Gary D. Yngve; James F. O'Brien; Jessica K. Hodgins

2000-01-01

74

Explosives tester  

DOEpatents

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.

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

2011-01-11

75

Scaling of light emission from detonating bare Composition B, 2,4,6-trinitrotoluene [C7H5(NO2)3], and PE4 plastic explosive charges  

Microsoft Academic Search

It is well known that an intense flash of light is emitted when an explosive charge is detonated. The light emission continues well beyond the actual detonation process due to shock excitation of the air molecules around the charge, as well as post-detonation reactions in the expanding products of the detonation. Various researchers have studied these emissions, and it has

Frederik J. Mostert; Marius Olivier

2011-01-01

76

Explosive welding: Principles and potentials  

SciTech Connect

Explosive welding is a solid-state process in which controlled explosive detonations force two or more metals together at high pressures. The resultant composite system is joined with a high-quality metallurgical bond. Explosive welding (or explosive bonding) is a high-pressure process in which contaminant surface films are plastically jetted off the base metals as a result of the collision of two metals. The time duration involved in the explosive welding event is so short that the reaction zone (or heat affected zone) between the constituent metals is microscopic. During the process, the first few atomic layers of each metal become plasma because of the high velocity of the impact (200 to 500 m/s, 660 to 1,640 ft/s.) The angle of collision causes the plasma to jet in front of the collision point, effectively scrub-cleaning both surfaces, and leaving clean metal behind.

Brasher, D.G.; Butler, D.J. [Northwest Technical Industries, Inc., Sequim, WA (United States)

1995-03-01

77

Detonation wave profiles in HMX based explosives  

Microsoft Academic Search

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

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

1998-01-01

78

Detonation wave profiles in HMX based explosives  

Microsoft Academic Search

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 mum average grain sizes, respectively. Planar detonations were produced by impacting the explosive with projectiles launched in a 72-mm bore gas

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

1998-01-01

79

White phosphorus poisoning--explosive encounter.  

PubMed

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

Pande, T K; Pandey, S

2004-03-01

80

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

SciTech Connect

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).

D.W. Hayden

2005-02-01

81

Explosive welding of pipes  

NASA Astrophysics Data System (ADS)

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.

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

2006-08-01

82

An Orientation to Explosive Safety.  

ERIC Educational Resources Information Center

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

Harris, Betty W.

1987-01-01

83

Test-based thermal explosion model for HMX  

Microsoft Academic Search

We present a thermal explosion (cookoff) model for an HMX-based plastic bonded explosive (LX-10). The thermalchemicalmechanical response of LX-10 is modeled based on the measurements from the scaled thermal explosion experiment (STEX) at the Lawrence Livermore National Laboratory. Confined LX-10 is heated at a rate of 1C\\/h until an explosion is observed. The modeled cookoff problem is simulated by the

Jack Jai-ick Yoh; M. A. McClelland; J. L. Maienschein; C. M. Tarver

2007-01-01

84

Explosive Entrances  

NASA Technical Reports Server (NTRS)

Explosive Technology, Inc. manufactured explosives first used by NASA to separate stages of the Gemini launch vehicle. When firemen need to get into a burning building or chop a hole to provide ventilation, axes can be devastatingly slow. Controlled explosives developed to separate manned upper stages of space rockets in case of mishap have been adapted to cutting emergency exits and demolishing unsafe buildings and bridges. Detonation cuts through thick steel girders or other materials more cleanly than torches or saws. This device can also cut emergency holes in airplanes and trains so surviving passengers can escape.

1976-01-01

85

(Packaging regulations for chemical explosives)  

SciTech Connect

The purpose of the trip was to visit Nobel Chemicals in Sweden and to confer with the Department of Transportation personnel in Sweden and in England on the technical and regulatory problems in the bulk shipping of the high explosives RDX and HMX. It is customary in the United States (US) to add isopropyl alcohol to the bulk shipment of water-wet high explosives RDX and HMX. The explosives are packed in cloth bags which are placed in plastic-lined fiber drums. The addition of alcohol presumably prevents mildewing of cloth bags and freezing of the wet explosives in cold weather. In Europe, however, these explosives are shipped in polyethylene-lined fiber drums with not less than 15% water only, even in cold weather. Water-wet frozen explosives have not proved to be any more sensitive than its unfrozen counterpart and no mildew problem has been encountered. It looks promising that the US Department of Transportation regulations can be changed to permit the bulk shipment of these explosives in water only without the addition of isopropyl alcohol. This is expected to cut down the packaging cost considerably. In addition, the packaging procedure in the US can be modernized by introducing more mechanical and efficient handling as seen at Nobel Chemicals. 2 figs.

Pal, B.C.

1988-02-17

86

Hazard characterization of explosives by use of the friction sensitivity test  

Microsoft Academic Search

Friction tests were conducted on a variety of explosives materials: pure liquids and solids, pastes, extrusion cast explosives, and plastic bonded explosives. The response of explosives to friction, especially for new formulations, is an important handling safety consideration. The test and hardware are described and results presented. 3 refs., 3 figs., 4 tabs.

Moody

1987-01-01

87

Explosive Magnetohydrodynamics.  

National Technical Information Service (NTIS)

Experimental studies on the production of short duration pulses of electrical power by MHD principles in a radial flow channel are presented. Plasma currents in excess of 10000 amperes were measured in a radially expanding explosive driven plasma. The pla...

M. S. Jones F. H. Webb P. Webster S. Handlin R. Harrison

1965-01-01

88

Explosive welding  

Microsoft Academic Search

1.The results of our research have shown that when plane charges of granular explosives are employed it is necessary to take into account the change in detonation velocity D as a function of the initial density?0 and the thickness of the charged0.The relations D=f(?0), D=f(d0) have been obtained experimentally and used to determine the impact parameters in explosive welding.2.The use

A. A. Deribas; V. M. Kudinov; F. I. Matveenkov; V. A. Simonov

1967-01-01

89

Explosive signatures: Pre & post blast  

NASA Astrophysics Data System (ADS)

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

Bernier, Evan Thomas

90

Explosive Welding of Pipes  

NASA Astrophysics Data System (ADS)

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%.

Burtseva, Olga

2007-06-01

91

Nanoengineered explosives  

DOEpatents

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

Makowiecki, D.M.

1996-04-09

92

Nanoengineered explosives  

DOEpatents

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

Makowiecki, Daniel M. (Livermore, CA)

1996-01-01

93

Detonation wave profiles in HMX based explosives  

SciTech Connect

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{percent} of crystal density. The powders had 120 and 10 {mu}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. {copyright} {ital 1998 American Institute of Physics.}

Gustavsen, R.L.; Sheffield, S.A.; Alcon, R.R. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

1998-07-01

94

61 FR 38084 - Commerce in Explosives; Implementation of Provisions of Public Law 104-132, the Antiterrorism and...  

Federal Register 2010, 2011, 2012, 2013

...Act, ``Implementation of Plastic Explosives Convention'', added new requirements to 18 U.S.C. Chapter...any marks of identification on such explosives, and such other information as the...regulation. This Treasury Decision adds a new Subpart J to the regulations in 27...Part 55 titled ``Marking of Plastic Explosives.'' All regulations relating to Title...the......

1996-07-23

95

Supernova explosions.  

NASA Technical Reports Server (NTRS)

The recent history of theoretical investigations of the supernova mechanism is considered, giving attention also to a number of nuclear physical problems which have yet to be solved in connection with the thermonuclear detonation. A variety of different processes of nucleo-synthesis are expected to occur in association with the supernova explosions. Aspects of the chemical evolution of the galaxy are discussed including the cosmic ray production of lithium, beryllium, and boron in the interstellar medium. Various hypotheses to account for the very large amount of light that comes from a supernova explosion are also examined.

Cameron, A. G. W.

1971-01-01

96

Engineering Design Handbook. Explosives Series. Explosive Trains.  

National Technical Information Service (NTIS)

The handbook presents theoretical and practical data pertaining to explosive trains. It includes consideration of the various elements which, in considerable variation, may constitute the explosive train of an item. The main charge of an explosive item, s...

1974-01-01

97

Detonation wave profiles in HMX based explosives  

Microsoft Academic Search

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 μm average grain sizes, respectively. Planar detonations were produced by impacting the explosive with projectiles launched in a 72-mm bore gas

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

1998-01-01

98

Terahertz spectroscopy techniques for explosives detection  

Microsoft Academic Search

Spectroscopy in the terahertz frequency range has demonstrated unique identification of both pure and military-grade explosives.\\u000a There is significant potential for wide applications of the technology for nondestructive and nonintrusive detection of explosives\\u000a and related devices. Terahertz radiation can penetrate most dielectrics, such as clothing materials, plastics, and cardboard.\\u000a This allows both screening of personnel and through-container screening. We review

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

2009-01-01

99

Explosive complexes  

DOEpatents

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.

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

2009-09-22

100

Population Explosion  

NSDL National Science Digital Library

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.

Program, The W.

101

Explosive complexes  

DOEpatents

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.

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

2011-08-16

102

Soda Explosion  

NSDL National Science Digital Library

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.

Connecticut, Science C.

1999-01-01

103

Insensitive Explosive Composition of Halogenated Copolymer and Triaminotrinitrobenzene.  

National Technical Information Service (NTIS)

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

T. M. Benziger

1976-01-01

104

Plastic plasticizer and radiation  

Microsoft Academic Search

Examination concerning the possibilities of decomposition of ; plasticizers such as phthalic acid esters and phosphoric acid esters or toxicity ; reduction thereof by the radiation has been made. (1) Radiation effects: Sham ; polluted solution having various kinds of concentrations of said ester was ; irradiated with ⁶°Co gamma -ray to 0.3 Mrad\\/hr. The results show that ; with

Sunada

1973-01-01

105

Shock Initiation of Heterogeneous Explosives  

SciTech Connect

The fundamental picture that shock initiation in heterogeneous explosives is caused by the linking of hot spots formed at inhomogeneities was put forward by several researchers in the 1950's and 1960's, and more recently. Our work uses the computer hardware and software developed in the Advanced Simulation and Computing (ASC) program of the U.S. Department of Energy to explicitly include heterogeneities at the scale of the explosive grains and to calculate the consequences of realistic although approximate models of explosive behavior. Our simulations are performed with ALE-3D, a three-dimensional, elastic-plastic-hydrodynamic Arbitrary Lagrange-Euler finite-difference program, which includes chemical kinetics and heat transfer, and which is under development at this laboratory. We developed the parameter values for a reactive-flow model to describe the non-ideal detonation behavior of an HMX-based explosive from the results of grain-scale simulations. In doing so, we reduced the number of free parameters that are inferred from comparison with experiment to a single one - the characteristic defect dimension. We also performed simulations of the run to detonation in small volumes of explosive. These simulations illustrate the development of the reaction zone and the acceleration of the shock front as the flame fronts start from hot spots, grow, and interact behind the shock front. In this way, our grain-scale simulations can also connect to continuum experiments directly.

Reaugh, J E

2004-05-10

106

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

Federal Register 2010, 2011, 2012, 2013

...Potassium chlorate and lead sulfocyanate explosive. Potassium nitrate explosive mixtures. Potassium nitroaminotetrazole...Sodium nitrate explosive mixtures. Sodium nitrate-potassium nitrate explosive mixture. Sodium picramate. Special...

2013-10-28

107

Diagnostic of the initiation phenomena of explosive trains  

Microsoft Academic Search

In details a test method is described which gives the delay times and buildup distances of the initiation of squeeze cast or plastic bonded high explosive charges. A special test setup arrangement is used to observe the incoming detonation wave of a high explosive train as the donor or initiating charge, then the breakthrough of the detonation wave at the

Manfred Held

2003-01-01

108

DETONATION PROPERTIES OF EXPLOSIVES CONTAINING NANOMETRIC ALUMINUM POWDER  

Microsoft Academic Search

Nanometric aluminum powder is known to react more rapidly than conventional, micron-size aluminum grades in propellant and explosive compositions. Defence Research and Development Canada - Valcartier (DRDC-V) and the Defence Science and Technology Organisation (DSTO) are collaborating to assess the potential of nanometric aluminum powders in explosive compositions. Various plastic-bonded explosives (PBXs) and TNT-based formulations have been developed to compare

Patrick Brousseau; Helen E. Dorsett; Matthew D. Cliff; C. John Anderson

109

Tenderizing Meat with Explosives  

NASA Astrophysics Data System (ADS)

Investigators at the Food Technology and Safety Laboratory have had success tenderizing meat by explosively shock loading samples submerged in water. This technique, referred to as the Hydrodynamic Pressure (HDP) Process, is being developed to improve the efficiency and reproducibility of the beef tenderization processing over conventional aging techniques. Once optimized, the process should overcome variability in tenderization currently plaguing the beef industry. Additional benefits include marketing lower quality grades of meat, which have not been commercially viable due to a low propensity to tenderization. The simplest and most successful arrangement of these tests has meat samples (50 to 75 mm thick) placed on a steel plate at the bottom of a plastic water vessel. Reported here are tests which were instrumented by Indian Head investigators. Carbon-composite resistor-gauges were used to quantify the shock profile delivered to the surface of the meat. PVDF and resistor gauges (used later in lieu of PVDF) provided data on the pressure-time history at the meat/steel interface. Resulting changes in tenderization were correlated with increasing shock duration, which were provided by various explosives.

Gustavson, Paul K.; Lee, Richard J.; Chambers, George P.; Solomon, Morse B.; Berry, Brad W.

2001-06-01

110

Analysis of Explosives  

Microsoft Academic Search

The analysis of explosives is of major importance in several analytical fields:1. Forensic identification of explosives is a major problem in the criminalistic investigation of a bombing which involves connecting the type of explosive used with the suspect. The detection and identification of explosive residues in debris material constitutes a highly difficult task. The thermal instability of most explosives, along

Jehuda Yinon; John C. Hoffsommer

1977-01-01

111

67 FR 48506 - Criteria for Certification of Explosives Trace Detection Systems  

Federal Register 2010, 2011, 2012, 2013

...and larger quantities of each listed explosive. The ETD must detect and differentiate explosive materials from among all other materials...capable of field retrofit to identify new threats, including the marking agents for plastic explosives required by Public Law 104-132....

2002-07-24

112

Passive Explosion Barrier.  

National Technical Information Service (NTIS)

The patent application relates generally to explosion barriers for mines, or the like, and more particularly to a passive explosion barrier that is responsive to relatively low velocity, as well as intermediate and high velocity explosion generated wind, ...

Liebman Corry

1975-01-01

113

Plastic Jellyfish.  

ERIC Educational Resources Information Center

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

Moseley, Christine

2000-01-01

114

Broadband terahertz time-domain and Raman spectroscopy of explosives  

Microsoft Academic Search

Broadband terahertz time-domain spectroscopy (THz-TDS) has been shown to be a valuable technique for the detection and analysis of explosives. In this paper, we present recent work on the use of this technique to analyse two pure explosives, 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) and 1,3-dinitrato-2,2-bis(nitratomethyl)propane (PETN) and three plastic explosives (Semtex, SX2 and Metabel). For each explosive, a clear and unique spectral absorption

A. D. Burnett; W. H. Fan; P. C. Upadhya; J. E. Cunningham; H. G. M. Edwards; J. Kendrick; T. Munshi; M. Hargreaves; E. H. Linfield; A. G. Davies

2007-01-01

115

Optically detonated explosive device  

NASA Technical Reports Server (NTRS)

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

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

1974-01-01

116

Chromospheric explosions  

NASA Technical Reports Server (NTRS)

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.

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

1986-01-01

117

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.

118

Ammonium nitrate explosive systems  

DOEpatents

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

Stinecipher, Mary M. (Los Alamos, NM); Coburn, Michael D. (Los Alamos, NM)

1981-01-01

119

Testing of explosive welding and welded joints: joint mechanism and properties of explosive welded joints  

Microsoft Academic Search

In this study physical mechanism of explosive welding joint was analysed. The mechanism refers to wavy joint with interpass\\u000a and without one. Plastic strain, viscosity and acoustic waves were applied to explain the problem. The own model of the mechanism\\u000a of oxide removal for the direct joint and test results confirming the bonding mechanism were showed.

Bogumil Wronka

2010-01-01

120

Plastic Stretch  

NSDL National Science Digital Library

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.

Stoebe, Thomas G.

2012-10-05

121

Comparison of the construction of unmarked deletion mutations in Mycobacterium smegmatis, Mycobacterium bovis bacillus Calmette-Gurin, and Mycobacterium tuberculosis H37Rv by allelic exchange.  

PubMed

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-Gurin (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

Pavelka, M S; Jacobs, W R

1999-08-01

122

Bioremediation of high explosives  

SciTech Connect

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).

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

123

Properties and Preparation of Explosives.  

National Technical Information Service (NTIS)

Contents: Oxyliquits; Nitro compounds; Ammonium nitrate explosives; Smoking powders and powders and powdered dynamons; Nitroethers (Nitrates); Nitroglycerin explosives; Smokeless powders; Chlorate and perchlorate explosives; Cardox and hydrox cartridges; ...

N. E. Yaremenko B. Y. Svetlov

1970-01-01

124

Plastic Packaging  

NSDL National Science Digital Library

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.

2008-01-01

125

Plastic bottle  

NSDL National Science Digital Library

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.

Jake Wasdin (None;)

2006-07-08

126

Process for preparing explosive  

US Patent & Trademark Office Database

A process for preparing a gas bubble sensitized explosive composition. The present process comprises preparing an explosive composition comprising a water-in-oil emulsion and mechanically entraining gas bubbles into the explosive composition. Low viscosity emulsion explosives are able to be sensitized by this process. There is a preference for wax free emulsions to be used. The process is applicable to emulsion explosives comprising ammonium nitrate particles. By providing a process for the mechanical entrainment of stable gas bubbles we allow explosive compositions to be sensitized on-site by readily available mixing means.

1990-06-26

127

Variable Energy Explosive Driver.  

National Technical Information Service (NTIS)

The patent application relates to an apparatus for providing a variable explosive energy source. The apparatus has an outer annular body with a wall containing a plurality of radial explosive chambers. A rotatable circular body positioned within the annul...

G. A. Greene

1974-01-01

128

Totally confined explosive welding  

NASA Technical Reports Server (NTRS)

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.

Bement, L. J. (inventor)

1978-01-01

129

Understanding Vented Gas Explosions.  

National Technical Information Service (NTIS)

The report is an introduction to vented gas explosions for nonspecialists, particularly designers of plants for flammable gases and liquids. The phenomena leading to pressure generation in vented gas explosions in empty and congested rooms are reviewed. T...

R. Lautkaski

1997-01-01

130

Inspection tester for explosives  

DOEpatents

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.

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

2007-11-13

131

Inspection tester for explosives  

DOEpatents

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.

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

2010-10-05

132

Binder study for HMX/TATB explosives  

SciTech Connect

Comparisons were made on Estane, Kraton G, and Kraton G with HyVac Oil for sensitivity and performance in plastic-bonded HMX/TATB formulations. Data obtained on sensitivity, performance, and processability suggest that Estane is superior, so it will be used in further studies. The goal of this study is to develop a relatively insensitive high explosive with a sensitivity between that of RX-26-AF and of PBX 9502.

Sanchez, J.A.

1985-09-01

133

Binder study for HMX\\/TATB explosives  

Microsoft Academic Search

Comparisons were made on Estane, Kraton G, and Kraton G with HyVac Oil for sensitivity and performance in plastic-bonded HMX\\/TATB formulations. Data obtained on sensitivity, performance, and processability suggest that Estane is superior, so it will be used in further studies. The goal of this study is to develop a relatively insensitive high explosive with a sensitivity between that of

1985-01-01

134

Combustion of damaged PBX 9501 explosive  

Microsoft Academic Search

Impact or thermal ignition of high explosives (HE) results in deformation that can lead to damage. Fractures or defects, combined with sufficient pressure, dramatically increase the available surface area and potentially changes even the mode of combustion. Recent impact and cookoff experiments on PBX 9501, (HMX, octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine, with a plasticized, Estane-based binder), have shown complex cracking patterns caused by impact

H. L. Berghout; S. F. Son; C. B. Skidmore; D. J. Idar; B. W. Asay

2002-01-01

135

Grain-scale Dynamics in Explosives  

SciTech Connect

High explosives can have reactions to external stimuli that range from mild pressure bursts to full detonation. The ability to predict these responses is important for understanding the performance as well as the safety and reliability of these important materials. At present, we have only relatively simple phenomenological computational models for the behavior of high explosives under these conditions. These models are limited by the assumption that the explosive can be treated as homogeneous. In reality the explosive is a highly heterogeneous composite of irregular crystallites and plastic binder. The heterogeneous nature of explosives is responsible for many of their unique mechanical and chemical properties. We use computational models to simulate the response of explosives to external mechanical stimuli at the grain-scale level. The ultimate goal of this work is to understand the detailed processes involved with the material response, so that we can develop realistic material models, which can be used in a hydrodynamics/multi-physics code to model real systems. The new material models will provide a more realistic description of the explosive system during the most critical period of ignition and initiation. The focus of this work is to use the results of grain-scale simulations to develop an advanced macroscopic reactive flow model that is consistent with our understanding of the grain-scale details, and that can incorporate such information quantitatively. The objective is to connect changes to observed properties of the explosive (grain size distribution, binder thickness distribution, void shape, size, and separation distribution, binder mechanical properties, etc.) with predictions of the resulting sensitivity and performance.

Reaugh, J E

2002-09-30

136

72 FR 18791 - Explosives  

Federal Register 2010, 2011, 2012, 2013

...industry has changed significantly. New forms of explosives have been developed (e.g., emulsions...employed to create, handle and use explosives (e.g., new kinds of bulk delivery vehicles...transportation, handling, and use of explosives. This new requirement is intended to ensure...

2007-04-13

137

Milk Plastic  

NSDL National Science Digital Library

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.

Workshop, Mission S.

2013-01-01

138

Constituent Properties and Formulation-Derived Interface Characteristics Contributing to Failure in Pharmaceutical and Explosive Composites.  

National Technical Information Service (NTIS)

Pharmaceutical tablets and plastic bonded explosives (PBX) obviously have very different purposes, but as materials they share many characteristics. Both types of composites are composed of crystalline ingredients incorporated in a polymeric matrix materi...

D. E. Hooks D. F. Bahr J. D. Yeager K. J. Ramos

2011-01-01

139

Method of Prediction of the Explosive Behavior of Highly Confined PBXs Submitted to Bullet Impact.  

National Technical Information Service (NTIS)

We describe the mechanisms which govern the bullet impact reactivity of strongly confined castable plastic bonded high explosives. We point out the parameters which drive the reaction. This is a deflagration to detonation transition, in the studied cases....

P. Monteagudo

1984-01-01

140

The search for high energy low vulnerability explosives  

SciTech Connect

Lawrence Livermore National Laboratory (LLNL) is currently attempting to formulate explosives which have approximately 30% greater energy than our current TATB/Kel-F explosive, while still passing the Department of Energy's (DOE) Insensitive High Explosive (IHE) criteria. The new formulations are comprised of HMX, TATB, and high density fluoropolymers and fluoroplasticizers. Variables in the study include the particle size of HMX, type of TATB (wet or dry aminated), the ratios of polymers to plasticizers, and formulation techniques. Initial small scale sensitivity tests and thermal testing have shown promising results. This paper will relate the up-to-date status of the project. 5 refs., 2 tabs.

Holtz, E. von; Scribner, K.; Moody, G.; McGuire, R.

1990-03-13

141

Low vulnerability explosives (LOVEX) for mass-use warheads  

SciTech Connect

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.

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

1990-03-13

142

Explosion proofing the ``explosion proof`` vacuum cleaner  

SciTech Connect

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.

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

1995-07-01

143

Gas gun for dynamic loading of explosives  

NASA Astrophysics Data System (ADS)

There has long been a need to understand the impact response of explosive materials, and continual improvements result from the design of careful, well-instrumented experiments. This article summarizes details of the design and construction of a laboratory facility capable of launching projectiles at explosive targets at velocities up to 1500 m s-1. There are two types of experiment that are required. In the first, a gun launches a plate of great planarity at an equally flat target. This geometry is known as plate impact and a target loaded in this manner experiences a state of one-dimensional strain. This loading is accomplished by launching plane impactors onto targets aligned to micron tolerances, normal to the impact axis to less than 0.5 mrad of tilt. In the second, it is required to attain the ability to recover impacted explosive targets that have been loaded in one-dimensional strain for subsequent microstructural assessment. The development of this capability will be described in a subsequent publication. The system is capable of containing reactive targets, where design must allow for complete detonation of the target (up to 250 g of explosive). The facility has been completed, is operational, and has been approved for use by the appropriate authorities. An example of a particle velocity sensor in use within a plastic-bonded explosive is given as illustration.

Bourne, N. K.

2004-01-01

144

Explosives detection: potential problems  

NASA Astrophysics Data System (ADS)

Most explosive detection technologies have been focused on nitro-based military explosives becuase they have figured in international terrorist incidents. Not only are they readily available through purchase or theft or from sponsoring states, but methods for home synthesis are widely available. Many of explosive detection technolgies now under development target a specific characteristic of military or commercial explosives (e.g. mass density, nitrogen density). However, as counterterrorist measures make traditional explosives more difficult to obtain or more risky to use, we should anticipate terrorists may turn to nontraditional explosives. There are hundreds of energetic compounds and many common explosives which, while they do not meet exacting military demands, might be effective terrorist tools. Although explosive handbooks list hundreds of explosives, this talk focuses on only a handful. These have been chosen because they do not follow the classic patterns of military explosives or because they are easily obtainable. This paper will also point out energetic systems that can produce violently exothermic reactions without the aid of traditional initiating systems, such as batteries or detonators.

Oxley, Jimmie C.

1995-09-01

145

New Mix Explosives for Explosive Welding  

NASA Astrophysics Data System (ADS)

Suggested and tested were some mix explosives---powder mixtures of a brisant high explosive (HE = RDX, PETN) and an inert diluent (baking soda)---for use in explosive welding. RDX and PETN were selected in view of their high throwing ability and low critical diameter. Since the decomposition of baking soda yields a huge amount of gaseous products, its presence ensures (even at a low HE percentage) a throwing speed that is sufficient for realization of explosive welding, at a reduced brisant action of charge. Mix chargers containing 30--70 wt % HE (the rest baking soda) have been tested experimentally and optimized. For study of possibility to reduce critical diameter of HE mixture, the mixture was prepared where HE crystal sizes did not exceed 10 ?m. The tests, which were performed with this HE, revealed that the mixture detonated stably with the velocity D 2 km/s, if the layer thickness was d = 2mm. The above explosives afford to markedly diminish deformations within the oblique impact zone and thus to carry out explosive welding of hollow items and thin metallic foils.

Andreevskikh, Leonid

2011-06-01

146

On Beyond the Standard Model for High Explosives: Challenges & Obstacles to Surmount  

Microsoft Academic Search

Plastic-bonded explosives (PBX) are heterogeneous materials. Nevertheless, current explosive models treat them as homogeneous materials. To compensate, an empirically determined effective burn rate is used in place of a chemical reaction rate. A significant limitation of these models is that different burn parameters are needed for applications in different regimes; for example, shock initiation of a PBX at different initial

Ralph Menikoff; Ralph Ds

2009-01-01

147

Experimental Determination of Thermodynamic Parameters for ``Explosive Products + Air'' Mixture in Closed Chambers  

Microsoft Academic Search

We study the influence of explosive products (EP) burnout under aerial environment on thermodynamic parameters of gases mixture in closed chambers with plasticized PETN based high explosive (HE). The results are adduced for measurements of steady-state pressure p and sound velocity c in ``EP + air'' mixture, when varying the mean charge density in the range of rho0 =0.2 -

E. E. Lin; A. V. Sirenko

2006-01-01

148

Shock initiation of explosive pellets at low temperature. [PETN, PBX9407, HNS-1  

Microsoft Academic Search

Electrically-driven flyer plates have been used to initiate the high explosives PETN, PBX-9407 and HNS-1 at 194°K and 77°K. Electrically-exploded aluminum foils accelerated 51-..mu..m thick plastic flyer plates to impact the explosive pellets. The flyer-plate components and the explosive pellets were cooled to the desired temperature by immersing them in dry ice (194°K) or liquid nitrogen (77°K). Two firing systems

1979-01-01

149

The development of an inert simulant for HNS/teflon explosive  

NASA Technical Reports Server (NTRS)

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

Elban, W. L.

1972-01-01

150

Modeling an Active (!!) Explosive Volcano  

NSDL National Science Digital Library

This activity is an active simulation of an explosive volcanic eruption. The model volcano is a plastic 35 mm film cannister that erupts (the lid blows off) when gas pressure generated by dissolving alka seltzer is sufficiently high. It is realistic in that the timing of the eruption is difficult to predict precisely and in that the eruption occurs when the pressure of the gas exceeds the confining pressure of the lid. The experiment can be modified to show that an eruption will not occur if there is not enough gas pressure generated or if gas is allowed to escape gradually. Students will explain how the build-up of gas from dissolving alka seltzer causes the lid of a film cannister to blow off, explain that build-up of gas pressure causes eruption of explosive volcanoes, and that the pressure comes from heating of dissolved gases in the magma, and they will delineate the similarities and differences between the model and an actual volcano.

151

Synaptic plasticity  

Microsoft Academic Search

Synaptic plasticity is manifested by long-lasting changes in synaptic potency. Increased potency is of special importance in relation to the neural basis of memory. Even mild repetitive stimulation evokes large and prolonged potentiations of hippocampal synapses, as is revealed by electrical recording either in vivo or in vitro. More importantly there is a matching hypertrophy of the synaptic spines on

John C. Eccles

1979-01-01

152

Modeling of buried explosions  

SciTech Connect

Los Alamos National Laboratory has been and continues developing techniques for modeling buried explosions using a large geotechnical centrifuge. When fully developed, the techniques should permit the accurate modeling of large explosions in complex geometries. Our intentional application is to study the phenomena of explosive cavity formation and collapse. However, the same methods should also be applicable to simulation of bursts shallow enough to produce craters, and perhaps even of airbursts in situations where soil overburden is important. We have placed primary emphasis on test bed construction methods and on accurate measurement of the ground shock produced by the explosions. 8 refs., 7 figs.

Gaffney, E.S.; Wohletz, K.H.; House, J.W.; Brown, J.A.

1987-01-01

153

Detection of explosives with laser-induced breakdown spectroscopy  

NASA Astrophysics Data System (ADS)

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.

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

2012-12-01

154

High-Explosive Field Tests, Explosion Phenomena and Environmental Impacts.  

National Technical Information Service (NTIS)

Methodologies are formulated to predict to magnitudes of high-explosive explosions phenomena for various high-explosive charge sizes and configurations and to relate these magnitudes to impacts on the natural physical and biological environment and on hum...

K. E. Gould

1981-01-01

155

Experimental and numerical analyses of explosive free forming  

Microsoft Academic Search

Explosive forming of metal blanks is accompanied by large plastic deformations at high strain rates. Mathematical models which include all of the variables in a complete rigorous manner do not exist. However, different aspects of the problem may be dealt width using numerical approximations. These analyses can be used to predict process parameters and can be used to eliminate most

S. A. A. Akbari Mousavi; M. Riahi; A. Hagh Parast

2007-01-01

156

Passive Explosion Barrier for Mines.  

National Technical Information Service (NTIS)

A passive explosion barrier is provided for use in mining operations in suppressing mine explosions. The barrier basically comprises a receptacle or tub which contains an explosion suppressing substance, such as water, and is mounted on a frame adjacent t...

I. Liebman R. Pro J. Corry

1979-01-01

157

Compact explosion diagrams  

Microsoft Academic Search

This paper presents a system to automatically generate compact explosion diagrams. Inspired by handmade illustrations, our approach reduces the complexity of an explosion diagram by rendering an exploded view only for a subset of the assemblies of an object. However, the exploded views are chosen so that they allow inference of the remaining unexploded assemblies of the entire 3D model.

Markus Tatzgern; Denis Kalkofen; Dieter Schmalstieg

2010-01-01

158

Performance of Emulsion Explosives  

Microsoft Academic Search

Some performance of a number of emulsion explosives containing glass micro-baloons were studied experimentally and theoretically. For each of the explosives, detonation velocity was measured and calculated and ballistic mortar tests and cylinder expansion tests were carried out. The results obtained enables a comparison of the usefulness of both testing methods. The influence of some metal nitrates contained in the

S. Cudzilo; P. Kohlicek; V. A. Trzcinski; S. Zeman

2002-01-01

159

Estimates of explosive yield  

NASA Technical Reports Server (NTRS)

Explosive yield as a function of propellant type and accident conditions was discussed along with the characteristics of propellant explosions. Three types of fuel-hypergolic, liquid oxygen-hydrocarbon, and liquid oxygen-liquid-hydrogen were considered. Data are also given on three modes (failure modes) of mixing: confinement by missile, confinement by ground surface, and high velocity impact.

1977-01-01

160

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.

161

Idaho Explosives Detection System  

Microsoft Academic Search

The Idaho Explosives Detection System was developed at the Idaho National Laboratory (INL) to respond to threats imposed by delivery trucks potentially carrying explosives into military bases. A full-scale prototype system has been built and is currently undergoing testing. The system consists of two racks, one on each side of a subject vehicle. Each rack includes a neutron generator and

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

2005-01-01

162

Detonation in Liquid Explosives  

Microsoft Academic Search

DURING the War a general investigation was commenced at the Road Research Laboratory, on the initiative of Dr. A. H. Davis, into the process of detonation in explosives, the programme including a photographic study of the detonation Waves in transparent liquid explosives-the sensitivity of some of which can be varied by adjusting the constitution-and their relation to primers of different

D. Croney

1948-01-01

163

Non-detonable explosive simulators  

DOEpatents

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.

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

1994-01-01

164

Non-detonable explosive simulators  

DOEpatents

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.

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

1994-11-01

165

Research topics in explosives - a look at explosives behaviors  

NASA Astrophysics Data System (ADS)

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.

Maienschein, J. L.

2014-05-01

166

Gunshot and Explosion Injuries  

PubMed Central

Context: An increase of terror-related activities may necessitate treatment of mass casualty incidents, requiring a broadening of existing skills and knowledge of various injury mechanisms. Objective: To characterize and compare injuries from gunshot and explosion caused by terrorist acts. Methods: A retrospective cohort study of patients recorded in the Israeli National Trauma Registry (ITR), all due to terror-related injuries, between October 1, 2000, to June 30, 2002. The ITR records all casualty admissions to hospitals, in-hospital deaths, and transfers at 9 of the 23 trauma centers in Israel. All 6 level I trauma centers and 3 of the largest regional trauma centers in the country are included. The registry includes the majority of severe terror-related injuries. Injury diagnoses, severity scores, hospital resource utilization parameters, length of stay (LOS), survival, and disposition. Results: A total of 1155 terror-related injuries: 54% by explosion, 36% gunshot wounds (GSW), and 10% by other means. This paper focused on the 2 larger patient subsets: 1033 patients injured by terror-related explosion or GSW. Seventy-one percent of the patients were male, 84% in the GSW group and 63% in the explosion group. More than half (53%) of the patients were 15 to 29 years old, 59% in the GSW group and 48% in the explosion group. GSW patients suffered higher proportions of open wounds (63% versus 53%) and fractures (42% versus 31%). Multiple body-regions injured in a single patient occurred in 62% of explosion victims versus 47% in GSW patients. GSW patients had double the proportion of moderate injuries than explosion victims. Explosion victims have a larger proportion of minor injuries on one hand and critical to fatal injuries on the other. LOS was longer than 2 weeks for 20% (22% in explosion, 18% in GSW). Fifty-one percent of the patients underwent a surgical procedure, 58% in the GSW group and 46% in explosion group. Inpatient death rate was 6.3% (65 patients), 7.8% in the GSW group compared with 5.3% in the explosion group. A larger proportion of gunshot victims died during the first day (97% versus 58%). Conclusions: GSW and injuries from explosions differ in the body region of injury, distribution of severity, LOS, intensive care unit (ICU) stay, and time of inpatient death. These findings have implications for treatment and for preparedness of hospital resources to treat patients after a terrorist attack in any region of the world. Tailored protocol for patient evaluation and initial treatment should differ between GSW and explosion victims. Hospital organization toward treating and admitting these patients should take into account the different arrival and injury patterns.

Peleg, Kobi; Aharonson-Daniel, Limor; Stein, Michael; Michaelson, Moshe; Kluger, Yoram; Simon, Daniel; Noji, Eric K.

2004-01-01

167

Fast Internal Temperature Measurements in PBX9501 Thermal Explosions  

NASA Astrophysics Data System (ADS)

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

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

2006-07-01

168

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

PubMed

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

Tam, Maggie; Pilon, Pierre; Zaknoun, Hafid

2013-09-01

169

DOE explosives safety manual  

NASA Astrophysics Data System (ADS)

The Department of Energy (DOE) policy requires that all activities be conducted in a manner that protects the safety of the public and provides a safe and healthful workplace for employees. DOE has also prescribed that all personnel be protected in any explosives operation undertaken. The level of safety provided shall be at least equivalent to that of the best industrial practice. The risk of death or serious injury shall be limited to the lowest practicable minimum. DOE and contractors shall continually review their explosives operations with the aim of achieving further refinements and improvements in safety practices and protective features. This manual describes the Department's explosive safety requirements applicable to operations involving the development, testing, handling, and processing of explosives or assemblies containing explosives. It is intended to reflect the state-of-the-art in explosives safety. In addition, it is essential that applicable criteria and requirements for implementing this policy be readily available and known to those responsible for conducting DOE programs. This document shall be periodically reviewed and updated to establish new requirements as appropriate. Users are requested to submit suggestions for improving the DOE Explosives Safety Manual through their appropriate Operations Office to the Office of Quality Programs.

1990-05-01

170

DOE explosives safety manual  

SciTech Connect

This manual is applicable to all DOE facilities engaged in operations of development, manufacturing, handling, storage, transportation (on site), processing, or testing of explosives, or assemblies containing explosives. It contains guidelines and standards for these operations in order to safeguard personnel and to prevent property damage. Criteria established by this manual are specific to high explosives but also apply to propellants and pyrotechnics when these materials can undergo explosive reactions. The standards of this manual deal with the operations involving explosives and the safe management of such operations. Design criteria for facilities used in conjunction with explosives operations are addressed only indirectly. Design criteria for explosives facilities are contained in DOE 6430.1, ''General Design Criteria Manual.'' It is not intended that existing physical facilities be changed arbitrarily to comply with this manual's provisions, except as required by law. Facility conditions determined to be noncompliant shall be resolved among the DOE Field Operations Office (FOO), Program Office, and the Office of Operational Safety (OOS). The standards are presented as either mandatory or advisory. Mandatory standards, denoted by the words ''shall,'' ''must,'' or ''will,'' are requirements that must be followed unless written authority for deviation is granted as an exemption by the DOE. Advisory standards denoted by ''should'' are standards that may be deviated from with a waiver granted by facility management. 2 refs.

Not Available

1987-08-01

171

Optically measured explosive impulse  

NASA Astrophysics Data System (ADS)

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.

Biss, Matthew M.; McNesby, Kevin L.

2014-06-01

172

Explosion Heat and Metal Acceleration Ability of High Explosives  

Microsoft Academic Search

Investigations of explosion heats of TNT and HMX show that in tests of unconfined charges the explosion products undergo intense secondary heating when approaching the wall of calorimetric bomb cavity. This secondary heating causes re-freezing the explosion products in conditions of low pressure. An inert metal casing whose mass is more than four times greater than that of explosive charge

M. N. Makhov

2004-01-01

173

Explosion Heat and Metal Acceleration Ability of High Explosives  

Microsoft Academic Search

Investigations of explosion heats of TNT and HMX show that in tests of unconfined charges the explosion products undergo intense secondary heating when approaching the wall of calorimetric bomb cavity. This secondary heating causes ``re-freezing'' the explosion products in conditions of low pressure. An inert metal casing whose mass is more than four times greater than that of explosive charge

M. N. Makhov

2004-01-01

174

Improved Coward explosive triangle for determining explosibility of mixture gas  

Microsoft Academic Search

It is very important to determine the explosibility of the mixture gas in the coal mine sealed area after a gas explosion occurred. If the combustible mixture gas has high explosive tendency, the potential re-occurring explosion would cause rescue workers death when they proceed with their rescue operations in the accident mine. Therefore, no one is allowed to go down

Jian-wei Cheng; Sheng-qiang Yang

2011-01-01

175

Lithium niobate explosion monitor  

DOEpatents

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.

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

1990-01-09

176

75 FR 3160 - Commerce in Explosives-Storage of Shock Tube With Detonators (2005R-3P)  

Federal Register 2010, 2011, 2012, 2013

...diameter plastic laminate tube coated with a very thin layer of explosive material. When initiated, it transmits a low energy wave from one point to another. The outer surface of the tube remains intact during and after functioning. DATES:...

2010-01-20

177

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

Federal Register 2010, 2011, 2012, 2013

...Potassium chlorate and lead sulfocyanate explosive. Potassium nitrate explosive mixtures. Potassium nitroaminotetrazole...Sodium nitrate explosive mixtures. Sodium nitrate-potassium nitrate explosive mixture. Sodium picramate. Special...

2010-11-17

178

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

Federal Register 2010, 2011, 2012, 2013

...Potassium chlorate and lead sulfocyanate explosive. Potassium nitrate explosive mixtures. Potassium nitroaminotetrazole...Sodium nitrate explosive mixtures. Sodium nitrate-potassium nitrate explosive mixture. Sodium picramate. Special...

2011-10-19

179

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

Federal Register 2010, 2011, 2012, 2013

...Potassium chlorate and lead sulfocyanate explosive. Potassium nitrate explosive mixtures. Potassium nitroaminotetrazole...Sodium nitrate explosive mixtures. Sodium nitrate-potassium nitrate explosive mixture. Sodium picramate. Special...

2012-09-20

180

Explosive nucleosynthesis: prospects  

NASA Astrophysics Data System (ADS)

Explosive nucleosynthesis is a combination of the nuclear physics of thermonuclear reactions, and the hydrodynamics of the plasma in which the reactions occur. It depends upon the initial conditions - the stellar evolution up to the explosive instability, and the nature of the explosion mechanism. Some key issues for explosive nucleosynthesis are the interaction of burning with hydrodynamics, the degree of microscopic mixing in convective zones, and the breaking of spherical symmetry by convection and rotation. Recent experiments on high-intensity lasers provides new opportunities for laboratory testing of astrophysical hydrodynamic codes. Implications of supernovae 1987A and 1998bw (GRB980425?), and /? Carina are discussed, as well as the formation of black holes or neutron stars.

Arnett, D.

2000-08-01

181

Explosives Vapor Characterization.  

National Technical Information Service (NTIS)

The vaporous emissions from seventeen explosives were investigated by gas chromatographic and combined gas chromatographic/mass spectrometric techniques using a novel collection device. The vapor emission rates were followed as a function of time untile t...

F. H. Jarke S. M. Gordon

1982-01-01

182

Molecular Models for Explosives.  

National Technical Information Service (NTIS)

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 fo...

J. P. Ritchie S. M. Bachrach

1987-01-01

183

Explosives Detecting Immunosensors.  

National Technical Information Service (NTIS)

To meet environmental remediation goals, there is a need for rapid, quantitative detection of hazardous pollutants such as explosives. Biosensors provide a rapid, specific, sensitive, portable, and inexpensive means to fulfill those needs. The Naval Resea...

A. Kusterbeck L. Shriver-Lake

2000-01-01

184

Explosion suppression system  

DOEpatents

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.

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

1992-01-01

185

Vacuum Pump Explosion Study.  

National Technical Information Service (NTIS)

An investigation was made into explosions and backfires occurring in vacuum pumps used on Navy oxygen component test stands. Research and testing uncovered several fire and toxicity hazards on these pumps which carry gaseous oxygen flows. Corrective recom...

H. H. Yuen T. D. Weikel

1972-01-01

186

Idaho Explosive Detection System  

SciTech Connect

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

Klinger, Jeff

2011-01-01

187

Idaho Explosives Detection System  

NASA Astrophysics Data System (ADS)

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

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

2005-12-01

188

Countering Improvised Explosive Devices.  

National Technical Information Service (NTIS)

We have no greater responsibility than providing for the safety and security for our citizens, allies, and partners, while providing an economic environment that promotes opportunity and prosperity. The use of improvised explosive devices (IEDs) threatens...

B. Obama

2013-01-01

189

Explosively Separable Casing.  

National Technical Information Service (NTIS)

An explosively separable casing including a cylindrical afterbody and a circular cover for one end of the afterbody is disclosed. The afterbody has a cylindrical tongue extending longitudinally from one end which is matingly received in a corresponding gr...

A. K. Jacobson R. E. Rychnovsky C. N. Visbeck

1983-01-01

190

Idaho Explosive Detection System  

ScienceCinema

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

Klinger, Jeff

2013-05-28

191

Nuclear explosive safety study process  

SciTech Connect

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

NONE

1997-01-01

192

Explosive Nucleosynthesis in Hypernovae  

Microsoft Academic Search

We examine the characteristics of nucleosynthesis in ``hypernovae,'' i.e., supernovae with very large explosion energies (>~1052 ergs). We carry out detailed nucleosynthesis calculations for these energetic explosions and compare the yields with those of ordinary core-collapse supernovae. We find that both complete and incomplete Si-burning takes place over more extended, lower density regions, so that the alpha-rich freezeout is enhanced

Takayoshi Nakamura; Hideyuki Umeda; Koichi Iwamoto; Ken'ichi Nomoto; Masa-aki Hashimoto; W. Raphael Hix; Friedrich-Karl Thielemann

2001-01-01

193

Explosive Welding and Cladding  

NASA Astrophysics Data System (ADS)

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.

Meuken, D.; Carton, E. P.

2004-07-01

194

Volcanic explosion on Io  

NASA Technical Reports Server (NTRS)

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

1979-01-01

195

Non-detonable and non-explosive explosive simulators  

DOEpatents

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.

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

1997-01-01

196

Non-detonable and non-explosive explosive simulators  

DOEpatents

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.

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

1997-07-15

197

Explosion of Comet Holmes  

NASA Astrophysics Data System (ADS)

We report on observations and theoretical interpretation of the explosion on comet 17P/Holmes 2007 Oct 23. Observed used the Spitzer mid-infrared spectrograph (5-40 microns), the Spitzer imaging photometer (24 and 70 microns), the Palomar Observatory 60-inch telescope, and frequent optical images from the Holloway comet observatory. The 2007 Nov 10 infrared spectral mapping revealed spatially diffuse emission with detailed mineralogical features, including those of small crystalline olivine grains. The 2008 Feb 27 spectra, and the central core of the 2007 Nov 10 spectral map, are nearly featureless, due to prevalence much larger grains that were ejected from the nucleus more slowly. The images and spectra in 2008 Mar can be segmented into three components: (1) a hemispherical shell due to the fastest (262 m/s), smallest (2 micron) debris; (2) a `blob' or `pseudonucleus' offset from the true nucleus, due to intermediate speed (93 m/s) and size (8 micron) particles; and (3) a `core' centered on the nucleus due to slower (9 m/s), larger (200 micron) ejecta. This decomposition of the mid-infrared observations also explains the temporal evolution of the mm-wave flux. The orientation of the leading edge of the ejecta shell and the ejecta `blob,' relative to the nucleus, do not change as the orientation of the Sun changes; instead, the configuration is imprinted by the orientation of the initial explosion. Using digitized versions of E. E. Barnard's images of the 1892 explosion of comet Holmes, we find remarkably similar properties of the explosion, including the direction of the ejecta remaining constant (rather than moving with the Sun). The earlier explosion was less energetic by a factor of about 20, meaning that the first and second most energetic cometary explosions witnessed by man are the 2007 and 1892 explosions of comet Holmes, in that order.

Reach, William T.; Vaubaillon, J.; Lisse, C. M.; Holloway, M.; Rho, J.

2009-09-01

198

Optimal design of elasto-plastic structures subjected to normal and extreme loads  

Microsoft Academic Search

When in the design of structures extreme loadings such as short time, high intensity dynamic pressure (explosion), impact or earthquake have to be taken into consideration then, except for special cases, the plastic reserves of the material can be utilized, but the development of excessive plastic deformations, residual displacements and the collapse have to be prevented. Following this design concept

S. Kaliszky; J. Lg

2006-01-01

199

Explosively separable casing  

DOEpatents

An explosively separable casing including a cylindrical afterbody and a circular cover for one end of the afterbody is disclosed. The afterbody has a cylindrical tongue extending longitudinally from one end which is matingly received in a corresponding groove in the cover. The groove is sized to provide a pocket between the end of the tongue and the remainder of the groove so that an explosive can be located therein. A seal is also provided between the tongue and the groove for sealing the pocket from the atmosphere. A frangible holding device is utilized to hold the cover to the afterbody. When the explosive is ignited, the increase in pressure in the pocket causes the cover to be accelerated away from the afterbody. Preferably, the inner wall of the afterbody is in the same plane as the inner wall of the tongue to provide a maximum space for storage in the afterbody and the side wall of the cover is thicker than the side wall of the afterbody so as to provide a sufficiently strong surrounding portion for the pocket in which the explosion takes place. The detonator for the explosive is also located on the cover and is carried away with the cover during separation. The seal is preferably located at the longitudinal end of the tongue and has a chevron cross section.

Jacobson, Albin K. (Albuquerque, NM); Rychnovsky, Raymond E. (Livermore, CA); Visbeck, Cornelius N. (Livermore, CA)

1985-01-01

200

Electromagnetic Field Effects in Explosives  

NASA Astrophysics Data System (ADS)

Present and previous research on the effects of electromagnetic fields on the initiation and detonation of explosives and the electromagnetic properties of explosives are reviewed. Among the topics related to detonating explosives are: enhancement of performance; and control of initiation and growth of reaction. Two series of experiments were performed to determine the effects of 1-T magnetic fields on explosive initiation and growth in the modified gap test and on the propagation of explosively generated plasma into air. The results have implications for the control of reactions in explosives and for the use of electromagnetic particle velocity gauges.

Tasker, D. G.; Whitley, V. H.; Lee, R. J.

2009-12-01

201

Direct Real-Time Detection of Vapors from Explosive Compounds  

SciTech Connect

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

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

2013-10-03

202

Explosion and Explosives. Vol 32, No. 6, 1971.  

National Technical Information Service (NTIS)

Contents: Future role of explosive experts; Studies on detonation pressure; Measurement of static charge of initiating explosives; A thin lead azide detonating fuse of thread type; The determination of the extent of cure by the attenuated total reflection...

1972-01-01

203

Explosion and Explosives, Volume 32, Number 6, 1971.  

National Technical Information Service (NTIS)

Contents: Future role of explosive experts; Studies on detonation pressure; Measurement of static charge of initiating explosives; A thin lead azide detonating fuse of thread type; The determination of the extent of cure by the attenuated total reflection...

1972-01-01

204

Viscosity Measurements of Malleable Explosive (MEX), a New Demolition Explosive,  

National Technical Information Service (NTIS)

The rheological characterisation of Malleable Explosive (MEX), a new explosive intended for demolition use, is presented. A Brookfield viscometer with T-bar spindles and Helipath stand is used to investigate the viscosity of MEX at shear rates similar to ...

H. H. Billon M. A. Parry

1988-01-01

205

A real explosion: the requirement of steam explosion pretreatment.  

PubMed

The severity factor is a common term used in steam explosion (SE) pretreatment that describes the combined effects of the temperature and duration of the pretreatment. However, it ignores the duration of the explosion process. This paper describes a new parameter, the explosion power density (EPD), which is independent of the severity factor. Furthermore, we present the adoption of a 5m(3) SE model for a catapult explosion mode, which completes the explosion within 0.0875 s. The explosion duration ratio of this model to a conventional model of the same volume is 1:123. The comparison between the two modes revealed a qualitative change by explosion speed, demonstrating that this real explosion satisfied the two requirements of consistency, and suggested a guiding mechanism for the design of SE devices. PMID:22858504

Yu, Zhengdao; Zhang, Bailiang; Yu, Fuqiang; Xu, Guizhuan; Song, Andong

2012-10-01

206

Continuous steam explosion  

SciTech Connect

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

Taylor, J.D.; Yu, E.K.C. [Stake Technology Ltd., Norval, Ontario (Canada)

1995-02-01

207

Bioremediation of explosives  

SciTech Connect

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.

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

1990-01-01

208

A plasticity concrete material model for DYNA3D  

Microsoft Academic Search

Lagrangian finite element codes with explicit time integration are extensively used for the analysis of structures subjected to explosive loading. Within these codes, numerous material models have been implemented. However, the development of a realistic but efficient concrete material model has proven complex and challenging.The plasticity concrete material model in the Lagrangian finite element code DYNA3D was assessed and enhanced.

L. Javier Malvar; John E. Crawford; James W. Wesevich; Don Simons

1997-01-01

209

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

NASA Astrophysics Data System (ADS)

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.

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

2013-09-01

210

An explosion in Tunguska  

NASA Astrophysics Data System (ADS)

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.

Nistor, Ioan

211

Shear band formation in plastic bonded explosive (PBX)  

SciTech Connect

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

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

1997-07-01

212

Shear band formation in plastic bonded explosive (PBX)  

SciTech Connect

Adiabatic shear bands can be a source of ignition and lead to detonation. At low to moderate deformation rates, 10{endash}1000 s{sup {minus}1}, two other mechanisms can also give rise to shear bands. These mechanisms are: 1) softening caused by micro-cracking and 2) a constitutive response with a non-associated flow rule as is observed in granular material such as soil. Brittle behavior at small strains and the granular nature of HMX suggest that PBX-9501 constitutive behavior may be similar to sand. A constitutive model for the first of these mechanisms is studied in a series of calculations. This viscoelastic constitutive model for PBX-9501 softens via a statistical crack model. A sand model is used to provide a non-associated flow rule and detailed results will be reported elsewhere. Both models generate shear band formation at 1{endash}2{percent} strain at nominal strain rates at and below 1000 s{sup {minus}1}. Shear band formation is suppressed at higher strain rates. Both mechanisms may accelerate the formation of adiabatic shear bands. {copyright} {ital 1998 American Institute of Physics.}

Dey, T.N.; Johnson, J.N. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

1998-07-01

213

Surface properties of potential plastic-bonded explosives (PBX)  

Microsoft Academic Search

A technique that measures the work of dewetting of a poly-coated glass slide using a liquid of known surface tension is described. The resultant data are analyzed using solvent pairs that give calculated values for solid-surface tension of the polymers. The solid-surface tension of a pressed TATB plate is similarly measured, and values for interfacial tension and work of adhesion

T. Rivera; M. L. Matuszak

1983-01-01

214

Attosecond molecular Coulomb explosion  

NASA Astrophysics Data System (ADS)

Molecular Coulomb explosion has been utilized as a precise temporal clock for probing ultrafast motion of nucleus and electrons during chemical reactions. With an intense attosecond pulse train in the extreme ultraviolet region, we were able to image attosecond molecular Coulomb explosion via two photon double ionization process. The present autocorrelation measurement, from which the duration of the attosecond pulse train was determined to be 300 as, serves as the first step toward a pump-and-probe measurement of molecular dynamics with attosecond temporal resolution.

Okino, Tomoya; Yamanouchi, Kaoru; Shimizu, Toshihiko; Furusawa, Kentaro; Hasegawa, Hirokazu; Nabekawa, Yasuo; Midorikawa, Katsumi

2006-12-01

215

High-nitrogen explosives  

SciTech Connect

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).

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

216

Explosive Welding with Nitroguanidine.  

PubMed

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

Sadwin, L D

1964-03-13

217

Optical detection of explosives: spectral signatures for the explosive bouquet  

Microsoft Academic Search

Research with canines suggests that sniffer dogs alert not on the odor from a pure explosive, but rather on a set of far more volatile species present in an explosive as impurities. Following the explosive trained canine example, we have begun examining the vapor signatures for many of these volatile impurities utilizing high resolution spectroscopic techniques in several molecular fingerprint

Tabetha Osborn; Sindhu Kaimal; Jason Causey; William Burns; Scott Reeve

2009-01-01

218

Shock initiation of bare and covered explosives by projectile impact  

Microsoft Academic Search

Shock initiation thresholds of bare and covered PBX-9404 and an HMX\\/TATB explosive called RX-26-AF were measured. The shocks were produced by the impact of flat-nosed and round-nosed steel projectiles in the velocity range of 0.5 to 2.2 km\\/s. Three types of coverings were used, 2 or 6 mm of tantalum, and a composite of aluminum and plastic. An Eulerian code

K. L. Bahl; H. C. Vantine; R. C. Weingart

1981-01-01

219

Equations of State and High-Pressure Phases of Explosives  

Microsoft Academic Search

Energetic materials, being the collective name for explosives, propellants, pyrotechnics, and other flash-bang materials,\\u000a span a wide range of composite chemical formulations. Most militarily used energetics are solids composed of particles of\\u000a the pure energetic material held together by a binder. Commonly used binders include various oils, waxes, and polymers or\\u000a plasticizers, and the composite is melt cast, cured, or

Suhithi M. Peiris; Jared C. Gump

220

Underwater explosive welding of thin tungsten foils and copper  

NASA Astrophysics Data System (ADS)

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

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

2011-11-01

221

Chemical destruction of HMX-based explosives with ammonium hydroxide  

SciTech Connect

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.

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

1995-09-01

222

A luminescent microporous metal-organic framework for the fast and reversible detection of high explosives.  

PubMed

Sensors and sensitivity: A highly luminescent microporous metal-organic framework, [Zn(2)(bpdc)(2)(bpee)] (bpdc = 4,4'-biphenyldicarboxylate; bpee = 1,2-bipyridylethene), is capable of very fast and reversible detection of the vapors of the nitroaromatic explosive 2,4-dinitrotoluene and the plastic explosive taggant 2,3-dimethyl-2,3-dinitrobutane, through redox fluorescence quenching with unprecedented sensitivity (see spectra). PMID:19180622

Lan, Anjian; Li, Kunhao; Wu, Haohan; Olson, David H; Emge, Thomas J; Ki, Woosoek; Hong, Maochun; Li, Jing

2009-01-01

223

Large Area and Short-Pulse Shock Initiation of a Tatb\\/hmx Mixed Explosive  

Microsoft Academic Search

The large area and short-pulse shock initiation experiments on the plastic bonded mixed explosive of TATB(80%) and HMX(15%) have been performed with an electric gun where a Mylar flyer of 10-19 mm in diameter and 0.05~0.30 mm in thickness was launched by an electrically exploding metallic bridge foil. The cylindrical explosive specimens (Phi16 mm8 mm in size) were initiated by

Wang Guiji; Sun Chengwei; Chen Jun; Liu Cangli; Zhao Jianheng; Tan Fuli; Zhang Ning

2007-01-01

224

Large Area and Short Pulsed Shock Initiation of A TATB\\/HMX Mixed Explosive  

Microsoft Academic Search

The large area and short pulsed shock initiation experiment on a plastic bonded mixed explosive of TATB(80%) and HMX(15%) has been performed with an electric gun where a mylar flyer of 19mm in diameter and 0.050.30mm in thickness is launched by an electrically exploding metallic bridge foil. The cylindrical explosive specimens (phi16mm x 8mm in size) were initiated by the

Guiji Wang; Chengwei Sun; Jun Chen; Cangli Liu; Fuli Tan; Ning Zhang

2007-01-01

225

Response surface study on production of explosively-welded aluminum-titanium laminates  

Microsoft Academic Search

This research was undertaken to produce strong and stiff, aluminum-titanium, multi-layered composites (laminates) by explosive welding, for applications requiring light-weight. The purpose of lamination is to create a material with superior mechanical properties resulting from plastic deformation produced by shock wave passage throughout each layer and from the presence of the explosively welded interfaces. A response surface study was performed

E. S. Ege; O. T. Inal; C. A. Zimmerly

1998-01-01

226

IMPROVEMENTS IN SUBTERRANEAN NUCLEAR EXPLOSIONS  

Microsoft Academic Search

It is suggested to let a non-military nuclear explosion take place in an ; evacuated subterranean space, created by digging or by a preliminary explosion. ; It is stated that due to the evacuation, less nuclear energy is mechanically ; wasted in the form of shock waves. Thus, the thermal output of the explosion is ; increased whereas subterranean destruction

Rougeron; P. M. C. M

1959-01-01

227

Low voltage nonprimary explosive detonator  

Microsoft Academic Search

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

Robert H. Dinegar; John Kirkham

1982-01-01

228

New explosive seam welding concepts  

NASA Technical Reports Server (NTRS)

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

Bement, L. J.

1973-01-01

229

Environmental fate of explosives  

Microsoft Academic Search

Waste disposal practices associated with military production of weapons, especially before and during World War II, have resulted in significant contamination of soils and ground water with high explosives such as TNT, RDX and HMX. Development of remediation and risk management strategies for these contaminated sites as well as development of approaches for sustainable use of active training and weapons

Judith C. Pennington; James M. Brannon

2002-01-01

230

Explosively Welded Scarf Joint.  

National Technical Information Service (NTIS)

This invention describes a method for producing a modified scarf weld which is not limited due to small gage of the parts to be welded. It uses the simple technique of explosive welding to bond and simultaneously shape sheet material so that an essentiall...

L. J. Bement

1972-01-01

231

Halting explosions with technology  

SciTech Connect

An account is given of an ignition suppression system developed under contract for the US Bureau of Mines. The machine mounted system utilises an ultra-violet flame detector, a cannister containing a dry powder extinguishing agent and a cannon-type dispersion unit. The results of explosion-suppression tests are given.

Not Available

1985-05-01

232

Aspherical supernova explosions  

NASA Astrophysics Data System (ADS)

Core collapse supernovae (SN) are the final stages of stellar evolution in massive stars during which the central region collapses, forms a neutron star (NS), and the outer layers are ejected. Recent explosion scenarios assumed that the ejection is due to energy deposition by neutrinos into the envelope, but detailed models do not produce powerful explosions. There is new and mounting evidence for an asphericity and, in particular, for axial symmetry in several supernovae which may be hard to reconcile within the spherical picture. This evidence includes the observed high polarization and its variation with time, pulsar kicks, high velocity iron-group and intermediate-mass elements material observed in remnants, direct observations of the debris of SN 1987A, etc. Some of the new evidence is discussed in more detail. To be in agreement with the observations, any successful mechanism must invoke some sort of axial symmetry for the explosion. We consider jet-induced/dominated explosions of core collapse supernovae. Our study is based on detailed 3-D hydrodynamical and radiation transport models. We find that the observations can be explained by low velocity, massive jets which stall well within the SN envelope. Such outflows may be produced by MHD-mechanisms, convective dominated accretion disks on the central object or asymmetric neutrino emissions. Asymmetric density/chemical distributions and, for SN 2002ap, off-center energy depositions have been identified as crucial for the interpretation of the polarization.

Hflich, Peter A.; Baade, Dietrich; Khokhlov, Alexei M.; Wang, Lifan; Wheeler, J. Craig

233

75 FR 5545 - Explosives  

Federal Register 2010, 2011, 2012, 2013

...LABOR Occupational Safety and Health Administration 29 CFR Part 1910 [Docket No. OSHA-2007-0032 (formerly Docket Nos. OSHA-S031-2006-0665 and OSHA-S-031)] RIN 1218-AC09 Explosives AGENCY: Occupational Safety and Health...

2010-02-03

234

Managing the data explosion  

USGS Publications Warehouse

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.

Hooper, Richard, P.; Aulenbach, Brent, T.

1993-01-01

235

Fundamentals of Explosive Welding  

Microsoft Academic Search

An account is given of the basic mechanism of adhesion in all welding processes, and a brief review of fusion and pressure welding techniques is given. A completely new method of welding which employs high explosives is briefly described and explained in terms of the principle used in the hollow charge, which wm developed during days of war to defeat

B. Crossland; A. S. Bahrani

1968-01-01

236

Portable raman explosives detection  

SciTech Connect

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.

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

2008-01-01

237

Portable Raman explosives detection  

Microsoft Academic Search

Recent advances in portable Raman instruments have dramatically increased their application to emergency response and forensics,\\u000a as well as homeland defense. This paper reviews the relevant attributes and disadvantages of portable Raman spectroscopy,\\u000a both essentially and instrumentally, to the task of explosives detection in the field.

David S. Moore; R. Jason Scharff

2009-01-01

238

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

SciTech Connect

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.

Ng, R.; Kwon, D.M.

1998-12-31

239

Hidden explosives detector employing pulsed neutron and x-ray interrogation  

DOEpatents

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.

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

1993-04-06

240

Hidden explosives detector employing pulsed neutron and x-ray interrogation  

DOEpatents

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.

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

1993-01-01

241

The using of LS-DYNA for the simulation of heat transfer in explosives  

NASA Astrophysics Data System (ADS)

The using of FEM and especially LS-DYNA3D code for the simulation of a heat transfer during the heating of the explosive charge is discussed in this paper. The characterization of explosive material properties (density, thermal conductivity, specific heat, heat of decomposition, the decomposition kinetics) is described. LS-DYNA3D code is used for the fitting of the appropriate kinetic model and for the simulation of the heat transfer during the slow cookoff test. The results of simulations are compared to the experimental values for the SEMTEX 1A plastic bonded explosive.

eleovsk, Jakub; Krupka, Miloslav

2007-07-01

242

Experimental Determination of Thermodynamic Parameters for ``Explosive Products + Air'' Mixture in Closed Chambers  

NASA Astrophysics Data System (ADS)

We study the influence of explosive products (EP) burnout under aerial environment on thermodynamic parameters of gases mixture in closed chambers with plasticized PETN based high explosive (HE). The results are adduced for measurements of steady-state pressure p and sound velocity c in ``EP + air'' mixture, when varying the mean charge density in the range of ?0 =0.2 - 11 kg/m3. The obtained data can be useful for solving tasks connected with the application of explosives in physical experiments.

Lin, E. E.; Sirenko, A. V.

2006-08-01

243

Explosion depths for phreatomagmatic eruptions  

NASA Astrophysics Data System (ADS)

phreatomagmatic explosions can result from the interaction of ascending magma with groundwater. Experiments over a wide range of energies show that for a given energy there is a depth below which an explosion will be contained within the subsurface (not erupt), and there is a corresponding shallower depth that will optimize ejecta dispersal. We combine these relationships with constraints on the energies of phreatomagmatic explosions at maar-diatreme volcanoes and show that most eruptions are likely sourced by explosions in the uppermost ~200 m, and even shallower ones (<100 m) are likely to dominate deposition onto tephra rings. Most explosions below ~200 m will not erupt but contribute to formation of, and to the vertical mixing of materials within, a diatreme (vent structure), with only rare very high energy explosions between ~200 and 500 m erupting. Similar constraints likely apply at other volcanoes that experience phreatomagmatic explosions.

Valentine, Greg A.; Graettinger, Alison H.; Sonder, Ingo

2014-05-01

244

Molecular hydrodynamics of high explosives  

SciTech Connect

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.

Belak, J.

1994-11-01

245

Ignition criterion and safety prediction of explosives under low velocity impact  

NASA Astrophysics Data System (ADS)

Due to the complexity of impact-induced reaction, it is difficult to predict and evaluate the ignition and safety of explosives under low velocity impact. Plastic deformation is very important to explosive ignition under impact loading. At low strain rates, plastic deformation can be treated as an isothermal process. The deformation under high-strain-rate is usually seen as an adiabatic process, and the deformation work is transformed into heat with the attendant temperature increase of the explosive. In this paper, we proposed an ignition criterion in terms of effective plastic work and specific plastic power to predict the ignition of explosives under low velocity impact. The plastic work begins to accumulate, when the specific plastic power (i.e., the plastic strain rate) in a local region meets a threshold value; and when the plastic work is sufficient enough, the ignition occurs. The criterion parameters are determined by numerical simulation using LS-DYNA. Numerical simulation is compared with experimental data in order to calibrate the numerical model. The threshold values of this ignition criterion for different configurations are determined. In order to evaluate the validity of the criterion, the predictions of the ignition time, ignition zone, threshold velocities in Steven test with different PBX size designs and various projectiles, as well as the ignition threshold conditions in a modified drop weight test, Susan test, and Spigot test, are carried out. The predicted results show a good agreement with experimental results, and the errors of the ignition threshold are less than 15% for all the experimental configurations.

Ma, Danzhu; Chen, Pengwan; Zhou, Qiang; Dai, Kaida

2013-09-01

246

Sensitivity of once-shocked, weathered high explosives  

SciTech Connect

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.

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

1998-07-01

247

Equations of State and High-Pressure Phases of Explosives  

NASA Astrophysics Data System (ADS)

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.

Peiris, Suhithi M.; Gump, Jared C.

248

Simulating Explosive Volcanic Eruptions  

NASA Astrophysics Data System (ADS)

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

Gisler, G. R.

2010-12-01

249

UNDERGROUND EXPLOSION EFFECTS  

Microsoft Academic Search

Measurements were made of surface and subsurface effects of an ; underground explosion of a 1.2-kt nuclear burst. The measurements included free-; field earth and air-blast effects, as well as loading on underground structural ; devices. From the 76 channels installed on TEAPOT Shot 7, 75 usable records were ; obtained. The free-field quantities measured include air-blast pressure, earth ;

D. C. Sachs; L. M. Swift

1958-01-01

250

QGP fireball explosion  

Microsoft Academic Search

We identify the major physics milestones in the development of strange\\u000ahadrons as an observable for both the formation of quark-gluon plasma, and of\\u000athe ensuing explosive disintegration of deconfined matter fireball formed in\\u000arelativistic heavy ion collisions at 160--20A GeV. We describe the physical\\u000aproperties of QGP phase and show agreement with the expectations based on an\\u000aanalysis of

J. Letessier; G. Torrieri; S. Hamieh; J. Rafelski

2000-01-01

251

Analysis of propagating explosions  

SciTech Connect

Weapons are often in close proximity to one another during transport or storage. If one weapon explodes, there is a possibility that the fragments generated will initiate a subsequent explosion in one or more neighboring weapons. Propagating explosions of this sort have the potential for severe consequences either because of the total amount of explosives that react or because the response of individual weapons may be particularly energetic. In this paper, we consider a well-defined problem in which the nature of the progression to all possible end states can be studied. We wish to determine the expected number of weapons to detonate along with other useful quantities. We examine the possible end states that the system can reach and show that we can represent the propagation process as a series of discrete time transitions. The transition probabilities from one state to the next then will depend only on the present state of the system. We present results of simulations that illustrate the effect of varying the detonation probability parameters.

Luck, L.B.; Eisenhawer, S.W.; Bott, T.F.

1996-07-01

252

Dust cluster explosion  

SciTech Connect

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).

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

253

Adhesion of explosives.  

PubMed

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

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

2013-06-01

254

Explosives signatures and analysis  

NASA Astrophysics Data System (ADS)

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

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

2008-05-01

255

Plastic Surgery for Teenagers  

MedlinePLUS

... eating disorders and obesity in children and adolescents: Theory, assessment, treatment and prevention. Washington, DC: APA Press, ... M. and the Adolescence Plastic Surgical Research Group. After plastic surgery: Adolescent-reported appearance ratings and appearance- ...

256

Plastic encapsulated parts  

SciTech Connect

Plastic semiconductor packages were characterized as possible alternatives for canned devices, which are susceptible to internal shorts caused by conductive particles. Highly accelerated stress testing (HAST) as well as electrical and mechanical testing were conducted on plastic technology devices.

Castillo, T.

1994-10-01

257

Antifouling Organometallic Structural Plastics.  

National Technical Information Service (NTIS)

Various organometallic plastics such as polymethacrylates, polystyrenes, and polyesters were prepared by chemically incorporating biocidal organometallic compounds on polymeric backbones. Organometallic plastics will be used as coatings and structural pla...

E. J. Dyckman J. A. Montemarano

1973-01-01

258

Plastics under the Bonnet.  

National Technical Information Service (NTIS)

This report examines the use of plastics materials in underbonnet components for passenger cars and trucks in Western Europe and the United States. Reasons why plastics have been specified by the automotive industry are discussed, including the need for w...

P. Scott

1981-01-01

259

Plasticity and Geotechnics  

NASA Astrophysics Data System (ADS)

Plasticity and Geotechnics is the first attempt to summarize and present, in one volume, the major developments achieved to date in the field of plasticity theory for geotechnical materials and its applications to geotechnical analysis and design.

Yu, Hai-Sui

260

Explosion Heat and Metal Acceleration Ability of High Explosives  

NASA Astrophysics Data System (ADS)

Investigations of explosion heats of TNT and HMX show that in tests of unconfined charges the explosion products undergo intense secondary heating when approaching the wall of calorimetric bomb cavity. This secondary heating causes ``re-freezing'' the explosion products in conditions of low pressure. An inert metal casing whose mass is more than four times greater than that of explosive charge prevents the secondary heating of products to the ``re-freezing'' temperature and rules out a change in their composition. Filling of calorimetric bomb cavity before explosion with an inert gas produces an effect similar to that of charge casing. The value of explosion heat, measured under conditions that preclude ``re-freezing'' of explosion products can serve as a measure of the energy content of high explosive. With the use of this parameter a simple method for predicting explosive performance in Cylinder Test has been developed. The method is based on the assumption that the coefficient of conversion of the chemical energy to the kinetic energy depends on the volumetric mole number of gaseous products.

Makhov, M. N.

2004-07-01

261

Tomorrow's Plastic World  

ERIC Educational Resources Information Center

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.

Macdonald, Averil

2005-01-01

262

Plastics in Building.  

ERIC Educational Resources Information Center

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

Skeist, Irving, Ed.

263

Processing of plastics  

PubMed Central

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.

Spaak, Albert

1975-01-01

264

Sea of Plastic  

NSDL National Science Digital Library

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.

Kqed

2012-08-08

265

Effects of explosions in hard rocks  

SciTech Connect

This work relates to explosions in hard rocks (ex: basalt, granite, limestone{hor_ellipsis}). Hard rock masses typically have a blocky structure created by the existence of geologic discontinuities such as bedding contacts, faults, and joints. At very high pressure-hundreds of kilobars and above-these discontinuities do not act separately, and the rock appears to be an equivalent continuous medium. At stress of a few tens of kilobars and below, the geologic discontinuities control the kinematics of the rock masses. Hence, the simulation of rock dynamics, anywhere but in the very-near source region, should account for those kinematics. In the very high pressure range continuum-based analysis is appropriate. In the discrete motion range one could consider: an equivalent continuum approach with anisotropy and plasticity. However, this is unlikely to provide the right kinematics; embedding discontinuities in continuum models, such as using joint elements and slip surfaces in finite elements. Typically, these are limited in terms of the separation of elements which may reconnect arbitrarily to new elements; complete discrete methods; ex: discrete elements, discontinuous displacement analysis (DDA). Discrete elements have progressed further than DDA We have chosen to develop and apply discrete elements models to explosion phenomenology in rocks.

Heuze, F.E.; Walton, O.R.; Maddix, D.M.; Shaffer, R.J.; Butkovich, T.R.

1993-05-01

266

Linear accelerator for explosive detection  

Microsoft Academic Search

A 14 MeV, S-band linear accelerator has been designed and built by Beta Development for use in the MIDEP explosive detection program at Titan\\/Spectron Division. The explosive detection technique utilizes photoneutron activation of the nitrogen which is an integral component in most commercial and military explosives. The accelerator was designed to be a small, high power, light weight, and portable

K. Whitham; R. C. Miller; H. Anamkath; J. R. Clifford; R. B. Miller; K. Habiger

1991-01-01

267

Biodegradability of Plastics  

PubMed Central

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.

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

2009-01-01

268

Low voltage nonprimary explosive detonator  

SciTech Connect

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.

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

1982-01-01

269

Towards optoelectronic detection of explosives  

NASA Astrophysics Data System (ADS)

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.

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

2013-06-01

270

Simplified explosive-weld evaluation  

NASA Technical Reports Server (NTRS)

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

Mclarty, D. M.

1976-01-01

271

Introduction to gasdynamics of explosions  

NASA Technical Reports Server (NTRS)

Questions concerning the genesis and sustenance of an explosion are investigated, giving attention to the mechanics of explosions, the gasdynamics of explosions, aspects of technological significance, and future prospects. The dynamics of exothermic processes is discussed together with the most prominent effects of explosions. Blast waves are considered, taking into account conservation principles, blast wave transformation, conservative equations in nondimensional form, the equation of state, Eulerian space profiles, Eulerian time profiles, Lagrangian time profiles, boundary conditions and integral relations, and self-similar flow fields.

Oppenheim, A. K.

1973-01-01

272

Modeling of explosion thermal radiation  

NASA Astrophysics Data System (ADS)

The hydrodynamic and radiation processes accompanying explosions of chemical explosives and fuel-air mixtures have been considered. Computer modeling of the radiation from a fire ball of explosion and a flame of diffusion combustion of a hydrocarbon fuel has been performed. The dependences of the heat flux density from the region occupied by explosion and combustion products on its temperature and geometric characteristics have been determined. Thermal load distributions on targets of different orientations in the vicinity of the energy release zone have been obtained. A comparison of the thermal parameters on radiation detectors with the criteria of thermal affection of people and ignition of combustible materials has been made.

Stepanov, K. L.; Stanchits, L. K.; Stankevich, Yu. A.

2011-01-01

273

Glassy metallic plastics  

NASA Astrophysics Data System (ADS)

This paper reports a class of bulk metallic glass including Ce-, LaCe-, CaLi-, Yb-, and Sr-based metallic glasses, which are regarded as glassy metallic plastics because they combine some unique properties of both plastics and metallic alloys. These glassy metallic plastics have very low glass transition temperature ( T g 25C to 150C) and low Youngs modulus (20 GPa to 35 GPa). Similar to glassy plastics, these metallic plastics show excellent plastic-like deformability on macro-, micro- and even nano-scale in their supercooled liquid range and can be processed, such as elongated, compressed, bent, and imprinted at low temperatures, in hot water for instance. Under ambient conditions, they display such metallic properties as high thermal and electric conductivities and excellent mechanical properties and other unique properties. The metallic plastics have potential applications and are also a model system for studying issues in glass physics.

Li, Jianfu; Wang, Junqiang; Liu, Xiaofeng; Zhao, Kun; Zhang, Bo; Bai, Haiyang; Pan, Mingxiang; Wang, Weihua

2010-03-01

274

Explosive turbulent magnetic reconnection.  

PubMed

We report simulation results for turbulent magnetic reconnection obtained using a newly developed Reynolds-averaged magnetohydrodynamics model. We find that the initial Harris current sheet develops in three ways, depending on the strength of turbulence: laminar reconnection, turbulent reconnection, and turbulent diffusion. The turbulent reconnection explosively converts the magnetic field energy into both kinetic and thermal energy of plasmas, and generates open fast reconnection jets. This fast turbulent reconnection is achieved by the localization of turbulent diffusion. Additionally, localized structure forms through the interaction of the mean field and turbulence. PMID:23829741

Higashimori, K; Yokoi, N; Hoshino, M

2013-06-21

275

Effect of "terminal explosion"  

NASA Astrophysics Data System (ADS)

We consider the entry into the Earth's atmosphere of a cosmic body at hypersonic speeds. Large aerodynamic charges, the forces of inertia, and heat flow to the body surface lead to mass loss or even destruction of the body. The movement of the fragment cloud caused by the destruction of the body is a separate problem. From observations, we know that the flight of a cosmic body often ends with a terminal flare. We present one possible estimate of the energy in the final stages of the destruction of the body, confirming the possibility of the observed effect of the "terminal explosion" of the meteoroid.

Egorova, L.

2012-01-01

276

Gasdynamics of explosions today.  

NASA Technical Reports Server (NTRS)

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

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

1971-01-01

277

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

SciTech Connect

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

Reaugh, J E

2011-11-22

278

Explosive components facility certification tests  

SciTech Connect

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

Dorrell, L.; Johnson, D. [Sandia National Labs., Albuquerque, NM (United States)

1995-08-01

279

The vortex explosion transition  

NASA Astrophysics Data System (ADS)

In type-II superconductors an applied magnetic field B, between the lower and upper critical values, produces a mixed state containing Abrikosov vortices. These vortices contain a quantum of magnetic flux h/2e and consist of a core with depressed order parameter and a pattern of perpetually circulating supercurrents. When B is applied parallel to a thin film, the circulating supercurrents get squeezed by the film surfaces causing the vortex core to become unstable and explode all the way across the film when the thickness d is below the critical value of dc = 4.4? here ? is the superconducting coherence length. For temperatures above the explosion condition dc(T) > d, the applied B cannot induce single parallel vortices, however perpendicular vortices can be generated spontaneously by thermal fluctuations. We observe a transition from non-dissipative to dissipative behavior at the explosion condition and find that the dynamics of the spontaneous perpendicular vortices can be tuned by the pairbreaking effect of the applied parallel field.

Kunchur, M. N.; Liang, M.; Gurevich, A.

2013-02-01

280

Controlled by Distant Explosions  

NASA Astrophysics Data System (ADS)

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 Cdric Ledoux (ESO). ESO PR Photo 17c/07 ESO PR Photo 17c/07 The Kueyen Control Room

2007-03-01

281

Laser machining of explosives  

DOEpatents

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.

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

2000-01-01

282

Safety Standard for Explosives, Propellants, and Pyrotechnics.  

National Technical Information Service (NTIS)

This document prescribes the National Aeronautics and Space Administration (NASA) safety standards/procedures for operations involving explosives handling and processing. These operations are an integral part of explosives and explosives-related developme...

1993-01-01

283

Laser-Based Detection Methods for Explosives.  

National Technical Information Service (NTIS)

Many well-known explosive detection techniques such as mass spectrometry and chromatography rely on close-contact sampling of surface residues or explosive vapors. Effective detection of explosive materials using laser-based methods has been demonstrated ...

A. W. Miziolek C. A. Munson J. F. De Lucia J. L. Gottfried K. L. McNesby

2007-01-01

284

Sandia Explosive Inventory and Information System.  

National Technical Information Service (NTIS)

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 acquisi...

D. A. Clements

1994-01-01

285

How Plastics Work  

NASA Astrophysics Data System (ADS)

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

Bloomfield, Louis

2013-03-01

286

Numerical Model for Hydrovolcanic Explosions.  

NASA Astrophysics Data System (ADS)

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

Mader, Charles; Gittings, Michael

2007-03-01

287

Nonterrorist suicidal deaths involving explosives.  

PubMed

Suicidal deaths involving explosives unconnected to terrorism are rare. The investigation of deaths from explosive devices requires a multidisciplinary collaborative effort, as demonstrated in this study. Reported are 2 cases of nonterrorist suicidal explosive-related deaths with massive craniocerebral destruction. The first case involves a 20-year-old man who was discovered in the basement apartment of his father's home seconds after an explosion. At the scene investigators recovered illegal improvised power-technique explosive devices, specifically M-100s, together with the victim's handwritten suicide note. The victim exhibited extensive craniofacial injuries, which medicolegal officials attributed to the decedent's intentionally placing one of these devices in his mouth. The second case involves a 46-year-old man who was found by his wife at his home. In the victim's facial wound, investigators recovered portions of a detonator blasting cap attached to electrical lead wires extending to his right hand. A suicide note was discovered at the scene. The appropriate collection of physical evidence at the scene of the explosion and a detailed examination of the victim's history is as important as documentation of injury patterns and recovery of trace evidence at autopsy. A basic understanding of the variety of explosive devices is also necessary. This investigatory approach greatly enhances the medicolegal death investigator's ability to reconstruct the fatal event as a means of separating accidental and homicidal explosive-related deaths from this uncommon form of suicide. PMID:12773843

Shields, Lisa B E; Hunsaker, Donna M; Hunsaker, John C; Humbert, Karl A

2003-06-01

288

Condensed Explosive Gas Dynamic Laser.  

National Technical Information Service (NTIS)

The condensed explosive of a gas dynamic laser is a condensed mixture of one or more nonhydrogenous organic explosive compounds, such as TNM, with a sufficient amount of aluminum or zirconium powder to supply energy to the products so that a temperature o...

J. Hershkowitz M. Y. D. Lanzerotti

1978-01-01

289

Explosives Detection for Aviation Security  

Microsoft Academic Search

The threat of terrorism against commercial aviation has received much attention in the past few years. In response, new ways to detect explosives and to combine techniques based on different phenomena into integrated security systems are being developed to improve aviation security. Several leading methods for explosives and weapons detection are presented.

Anthony Fainberg

1992-01-01

290

Optical Pressure Measurements of Explosions.  

National Technical Information Service (NTIS)

High-speed video and streak-camera imaging are used to measure peak pressures for explosions of spherical charges of C-4. The technique measures the velocity of the air shock produced by the detonation of the explosive charges, converts this velocity to a...

K. L. McNesby M. M. Biss R. A. Benjamin R. A. Thompson

2013-01-01

291

Calculating overpressure from BLEVE explosions  

Microsoft Academic Search

Although a certain number of authors have analyzed the prediction of boiling liquid expanding vapour explosion (BLEVE) and fireball effects, only very few of them have proposed methodologies for predicting the overpressure from such explosions. In this paper, the methods previously published are discussed and shown to introduce a significant overestimation due to the erroneous thermodynamic assumptionsideal gas behaviour and

E. Planas-Cuchi; J. M. Salla; J. Casal

2004-01-01

292

After an explosion, what happens  

Microsoft Academic Search

Whenever an explosion or fire occurs in the presence of LP-gas, an investigation is usually necessary to determine the cause and to protect the marketer from unreasonable lawsuits. Haag Engineering Co., Dallas, urges that the evidence be studied carefully so that mistakes do not obliterate evidence before a conclusion is reached. Overall effects of the explosion should be examined to

1975-01-01

293

Radiation-induced explosive initiation  

NASA Astrophysics Data System (ADS)

A model for explosive initiation under the influence of high energy radiation has been developed. The possibility for comparing explosive initiation conditions under the influence of radiation pulse and shock wave loads of microsecond duration has been shown and the initiation conditions as a function of the radiolysis constants have been determined.

Yakovlev, M.

1999-08-01

294

Radiation-induced explosive initiation  

Microsoft Academic Search

A model for explosive initiation under the influence of high energy radiation has been developed. The possibility for comparing explosive initiation conditions under the influence of radiation pulse and shock wave loads of microsecond duration has been shown and the initiation conditions as a function of the radiolysis constants have been determined.

M. Yakovlev

1999-01-01

295

Kaliski's explosive driven fusion experiments  

Microsoft Academic Search

An experiment performed by a group in Poland on the production of DD fusion neutrons by purely explosive means is discussed. A method for multiplying shock velocities ordinarily available from high explosives by a factor of ten is described, and its application to DD fusion experiments is discussed.

1979-01-01

296

Explosive welding of metal plates  

Microsoft Academic Search

This paper describes a study of explosive welding of metal plates. The properties of a locally prepared mix of 77\\/23 ammonium nitrate and fuel oil (ANFO) explosive and the dynamics of the plates are investigated and the results from welding tests presented. The strength of the clad plates is measured and ultrasonic inspection performed to identify and locate defects. The

S. A. A. Akbari-Mousavi; L. M. Barrett; S. T. S. Al-Hassani

2008-01-01

297

Recent developments in explosive welding  

Microsoft Academic Search

Explosion welding (EXW) is one of the joining methods consisting of a solid state welding process in which controlled explosive detonation on the surface of a metal. During the collision, a high velocity jet is produced to remove away the impurities on the metal surfaces. Flyer plate collides with base plate resulting in a bonding at the interface of metals.

Fehim Findik

2011-01-01

298

Explosive Welding for Remote Applications  

NASA Technical Reports Server (NTRS)

Explosive seam welding produces up to 100-percent joint strength. Ribbon explosive activated by remote energy source produces metallurgically sound joint. Success of technique verified for joints between like metals and joints between two different metals. Applications include structural assembly in toxic atmospheres and in radioactive or otherwise hazardous environments.

Bement, L. J.

1985-01-01

299

Monitored Natural Attenuation of Explosives  

Microsoft Academic Search

Explosives are subject to several attenuation processes that potentially reduce concentrations in groundwater over time. Some of these processes are well defined, while others are poorly understood. The objective of the project was to optimize data collection and processing procedures for evaluation and implementation of monitored natural attenuation of explosives. After conducting experiments to optimize data quality, a protocol was

Judith C. Pennington; James M. Brannon; Douglas Gunnison; D. W. Harrelson; M. Zakikhani; Paul Miyares; Thomas F. Jenkins; Joan Clarke; Charolett Hayes; David Ringleberg; Ed Perkins; Herb Fredrickson

2001-01-01

300

Chemistry and Properties of Liquid Explosives  

Microsoft Academic Search

Liquid explosives are classified in several groups, and groups of liquid explosives characterised. Special attention is given\\u000a to properties of liquid explosives based on the mixtures of hydrogen peroxide and alcohols and mixtures of hydrogen peroxide\\u000a with solid fuels. Some specific aspects of explosive behaviour of liquid explosives are discussed. Important procedures for\\u000a the detection of liquid explosives and limits

P. Mostak

301

The Scaled Thermal Explosion Experiment  

SciTech Connect

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

Wardell, J F; Maienschein, J L

2002-07-05

302

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

SciTech Connect

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

Woodyard, J.D.; Burgess, C.E. [West Texas A and M Univ., Canyon, TX (United States); Rainwater, K.A. [Texas Tech Univ., Lubbock, TX (United States)

1999-03-01

303

Broadband terahertz time-domain and Raman spectroscopy of explosives  

NASA Astrophysics Data System (ADS)

Broadband terahertz time-domain spectroscopy (THz-TDS) has been shown to be a valuable technique for the detection and analysis of explosives. In this paper, we present recent work on the use of this technique to analyse two pure explosives, 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) and 1,3-dinitrato-2,2-bis(nitratomethyl)propane (PETN) and three plastic explosives (Semtex, SX2 and Metabel). For each explosive, a clear and unique spectral absorption fingerprint is found, which can be attributed to oscillations of the molecular lattice. Temperature dependent terahertz absorption measurements of RDX show that the observed vibrational modes are anharmonic in nature. Terahertz spectra are compared with Raman spectra, and the similarities and differences between the spectra produced by the two techniques are discussed. A molecular mechanics calculation approach is used to calculate vibrational intensities and frequencies, and these results are compared with experimental results at both room temperature and 4 K.

Burnett, A. D.; Fan, W. H.; Upadhya, P. C.; Cunningham, J. E.; Edwards, H. G. M.; Kendrick, J.; Munshi, T.; Hargreaves, M.; Linfield, E. H.; Davies, A. G.

2007-05-01

304

Reaction of Shocked but Undetonated HMX-Based Explosive  

NASA Astrophysics Data System (ADS)

Cylindrical samples of the pressed plastic bonded HMX based explosive EDC37, backed by metal discs, were shocked through a stainless steel attenuator by an explosive donor. Reaction of the EDC37 sample was diagnosed with embedded PVDF pressure gauges and a distance to detonation for the geometry was determined. Sample length was then reduced to less than the observed detonation distance and laser interferometry was used to record the free surface velocity of the metal backing disc. The results provide data on the metal driving energy liberated by explosive which is shocked and reacting but not detonated. The results are compared with 2-D Eulerian calculations incorporating a 3-term ignition and growth reactive burn model with desensitisation. It is found that a parameter set for the reaction model which replicates the PVDF pressure profiles before reflection also gives good agreement to the metal disc velocity history at early times. The results show that an appreciable fraction of the metal driving potential of an explosive can be released without detonation being established.

Taylor, P.; Salisbury, D. A.; Markland, L. S.; Winter, R. E.; Andrew, M. I.

2002-07-01

305

Reaction of Shocked but Undetonated HMX-Based Explosive  

NASA Astrophysics Data System (ADS)

Cylindrical samples of the pressed plastic bonded HMX-based explosive EDC37, backed by metal discs, were shocked through a stainless steel attenuator by an explosive donor. Reaction of the EDC37 sample was diagnosed with embedded PVDF pressure gauges and a run distance to detonation for the geometry was determined. Sample length was then reduced to less than the observed run distance and laser interferometry was used to record the free surface velocity of the metal backing disc. The results provide data on the metal driving energy liberated by the explosive which is shocked and reacting but not detonated. The results are compared with Eulerian hydrocode calculations incorporating the three term Lee and Tarver reaction model with desensitisation. It is found that a parameter set for the reaction model which replicates the PVDF pressure profiles before reflection also gives good agreement to the metal disc velocity history at early times. The results show that an appreciable fraction of the metal driving potential of an explosive can be released without detonation being established.

Taylor, P.; Salisbury, D. A.; Markland, L. S.; Winter, R. E.

2001-06-01

306

Mixing in explosions  

SciTech Connect

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.

Kuhl, A.L.

1993-12-01

307

Watersheds and Explosive percolation  

NASA Astrophysics Data System (ADS)

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.

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

308

Careers in Plastics  

NSDL National Science Digital Library

Teachers' Domain presents this video as part of a series on advanced technological education. Filmed at NPE: The International Plastics Showcase, the video features careers in the plastics industry. Degrees that lead to careers in plastics are discussed. The video also talks about emerging green technologies and how they relate to the plastics industry. The video may be viewed online or downloaded. To download the clip, users must create a free login for Teachers' Domain. Running time for this QuickTime video is 2:13. Educators will also find a background essay, discussion questions, and standards alignment for the material.

2010-09-30

309

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.

2010-10-05

310

Coating Plastic Lenses  

NASA Technical Reports Server (NTRS)

Bell & Howell Company (at their own expense) arranged to work with an Ames Research Center scientist to learn NASA's technique of plasma polymerization. Plastic is easily formed into aspherical surfaces and compound lenses are made from plastics of different refractive indexes. Plastic lenses are injection molded at a tenth the cost of making glass lenses and are lighter than glass and cannot shatter. Scratches scatter light reducing light transmission. This technique is used for coating plastic lenses of film projectors and other optical equipment.

1976-01-01

311

Additives in plastics.  

PubMed Central

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.

Deanin, R D

1975-01-01

312

Optical detection of explosives: spectral signatures for the explosive bouquet  

NASA Astrophysics Data System (ADS)

Research with canines suggests that sniffer dogs alert not on the odor from a pure explosive, but rather on a set of far more volatile species present in an explosive as impurities. Following the explosive trained canine example, we have begun examining the vapor signatures for many of these volatile impurities utilizing high resolution spectroscopic techniques in several molecular fingerprint regions. Here we will describe some of these high resolution measurements and discuss strategies for selecting useful spectral signature regions for individual molecular markers of interest.

Osborn, Tabetha; Kaimal, Sindhu; Causey, Jason; Burns, William; Reeve, Scott

2009-05-01

313

Shock initiation of bare and covered explosives by projectile impact  

SciTech Connect

Shock initiation thresholds of bare and covered PBX-9404 and an HMX/TATB explosive called RX-26-AF were measured. The shocks were produced by the impact of flat-nosed and round-nosed steel projectiles in the velocity range of 0.5 to 2.2 km/s. Three types of coverings were used, 2 or 6 mm of tantalum, and a composite of aluminum and plastic. An Eulerian code containing material-strength and explosive-initiation models was used to evaluate our ability to calculate the shock initiation thresholds. These code calculations agreed well with the flat-nosed experimental data, but not so well with the round-nosed data.

Bahl, K.L.; Vantine, H.C.; Weingart, R.C.

1981-04-22

314

Paste extrudable explosives: Their history and their current status  

SciTech Connect

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.

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

1990-03-13

315

Noninvasive detection of concealed liquid explosives using Raman spectroscopy.  

PubMed

We present a Raman spectroscopic method for the noninvasive detection of liquid explosives within bottles, and other packaging, of substantially higher sensitivity and wider applicability than that currently available via conventional Raman spectroscopy. The approach uses a modification of the spatially offset Raman spectroscopy (SORS) concept, which permits the interrogation of a wide range of containers, including transparent, colored, and diffusely scattering plastic and glass beverage, medicine, and cosmetic bottles, with no change in experimental geometry. The enhanced sensitivity is achieved by the technique's inherent ability to effectively suppress fluorescence and Raman contributions originating from the wall of the container. The application is demonstrated on the noninvasive detection of hydrogen peroxide solution, a critical component of a number of liquid explosives. In contrast to conventional Raman spectroscopy, the modified SORS concept enables the detection of concealed hydrogen peroxide solution in all the studied cases. PMID:17880183

Eliasson, C; Macleod, N A; Matousek, P

2007-11-01

316

49 CFR 173.62 - Specific packaging requirements for explosives.  

Code of Federal Regulations, 2013 CFR

... The Explosives Table specifies the Packing Instructions assigned to each explosive...of the Explosives Table specifies the Packing Instruction (PI) which must be used for packaging the explosive. The Explosives Packing Method Table in paragraph (c) of...

2013-10-01

317

Detection of explosives in soils  

DOEpatents

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.

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

318

Shock desensitizing of solid explosive  

SciTech Connect

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.

Davis, William C [Los Alamos National Laboratory

2010-01-01

319

Optimal dynamic detection of explosives  

NASA Astrophysics Data System (ADS)

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.

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

2011-05-01

320

Mechanism of wave formation at the interface in explosive welding  

NASA Astrophysics Data System (ADS)

Some of the main progress on the investigation of the mechanism of the wave formation in explosive welding at the Institute of Mechanics is summarized and others' previous works are reviewed. Our systematic experiments and analysis do not substantiate the theory of wave formation based on Karman vortex-street analogy or Helmholtz instability. On the contrary, they show that material strength insensitive to strain rate plays an important role. A simple hydro-plastic model is presented to explain the main features regarding the interfacial wave formation and to estimate the magnitude of wave length. The result is in broad agreement with experiment.

Chemin, Cheng; Qingming, Tan

1989-05-01

321

Anaerobic Metabolism and Bioremediation of Explosives-Contaminated Soil  

NASA Astrophysics Data System (ADS)

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

Boopathy, Raj

322

Cavitation Instabilities in Plastics and Rubber-Modified Plastics  

Microsoft Academic Search

Spherical void expansion in plastics and rubber-modified plastics is investigated under radial traction conditions. The plastics\\u000a are modeled as elastic-plastic pressure-sensitive materials and the rubbers are modeled as nonlinearly elastic materials.\\u000a First, the growth of a spherical void in an infinite plastic matrix is investigated under remote radial traction conditions.\\u000a The results show that the cavitation stress of the plastic

W. J. Chang; J. Pan

1997-01-01

323

Luminescence in Plastics  

Microsoft Academic Search

THE luminescence of organic molecules dissolved in a variety of plastics has been examined during the course of a search for new organic optical maser materials. Most plastics are compatible with organic compounds, are optically homogeneous even at liquid nitrogen temperature, have high dielectric strength, and can, of course, be fabricated in a wide variety of forms. In some cases,

Gerald Oster; Nicholas Geacintov; Ahsan Ullah Khan

1962-01-01

324

Biodegradation of plastics  

Microsoft Academic Search

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.

Masayuki Shimao

2001-01-01

325

Biodegradable Plastics from Cellulose  

Microsoft Academic Search

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

Mariko Yoshioka; Nobuo Shiraishi

2000-01-01

326

Imaging synaptic plasticity  

PubMed Central

Over the past decade, the use and development of optical imaging techniques has advanced our understanding of synaptic plasticity by offering the spatial and temporal resolution necessary to examine long-term changes at individual synapses. Here, we review the use of these techniques in recent studies of synaptic plasticity and, in particular, long-term potentiation in the hippocampus.

2011-01-01

327

Plastic heliostat enclosure analysis  

Microsoft Academic Search

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,

M. J. Berry

1984-01-01

328

Corn Starch Plastic  

NSDL National Science Digital Library

In this activity, learn how you can make plastic out of corn (corn starch). Use this activity to explore polymers and PLA, polylactic acid, a plastic that is easier to compost. This activity guide includes a step-by-step instructional video. Safety note: Younger learners will require adult supervision.

Center, Saint L.

2013-02-11

329

Plastic in the Pacific  

NSDL National Science Digital Library

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.

Kqed

2012-08-08

330

Inelastic Behavior of Plastics.  

National Technical Information Service (NTIS)

The present interim report describes the state of the ISD work on inelastic calculation of plastics components. The work done until now dealt with two problems: the prediction of long-time behavior of plastics components (light domes) for the loading cond...

J. H. Argyris G. Faust J. Szimmat K. J. Willam

1979-01-01

331

Phenotypic plasticity in nematodes  

PubMed Central

Model systems, including C. elegans, have been successfully studied to understand the genetic control of development. A genotypes phenotype determines its evolutionary fitness in natural environments, which are typically harsh, heterogeneous and dynamic. Phenotypic plasticity, the process by which one genome can produce different phenotypes in response to the environment, allows genotypes to better match their phenotype to their environment. Phenotypic plasticity is rife among nematodes, seen both as differences among life-cycles stages, perhaps best exemplified by parasitic nematodes, as well as developmental choices, such as shown by the C. elegans dauer/non-dauer developmental choice. Understanding the genetic basis of phenotypically plastic traits will probably explain the function of many genes whose function still remains unclear. Understanding the adaptive benefits of phenotypically plastic traits requires that we understand how plasticity differs among genotypes, and the effects of this in diverse, different environments.

Viney, Mark; Diaz, Anaid

2012-01-01

332

Track recording plastic compositions  

NASA Technical Reports Server (NTRS)

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.

Tarle, Gregory (Inventor)

1983-01-01

333

Prompt detonation of secondary explosives by laser  

Microsoft Academic Search

Secondary high explosives have been promptly detonated by directing a laser beam of various wavelengths from 266 nanometers to 1.06 micron on the surface of the explosives. For this paper ''prompt'' means the excess transit time through an explosive charge is \\/approximately\\/250 nanoseconds (or less) less than the accepted full detonation velocity time. Timing between laser pulse, explosive initiation and

Paisley

1989-01-01

334

Explosives detection with hard-wired moths  

Microsoft Academic Search

AbstractInsects, such as moths, can be trained to respond to explosives odors. A prototype system that can use trained insects such as moths to detect explosives was designed, assembled, and tested. It compares the electromyographic signals of insects trained to respond or not respond to a target explosive vapor in order to determine whether or not explosive devices, such as

Tony L. King; Frank M. Horine; Kevin C. Daly; Brian H. Smith

2004-01-01

335

EXPLOSIVE WELDING SIMULATION OF MULTILAYER TUBES  

Microsoft Academic Search

Summary. Explosive welding is a process which uses explosive detonation to propel the flyer plate material into the base material to produce a sound joint. Experimental tests have been performed to explosively welded aluminum 5056, aluminum 1015 and stainless steel 304 tubes in one step. The tests have been carried out using various stand-off distances and explosive ratios. Various interface

A. A. Akbari Mousavi; G. Joodaki

336

Quantitative understanding of explosive stimulus transfer  

NASA Technical Reports Server (NTRS)

The mechanisms of detonation transfer across hermetically sealed interfaces created by necessary interruptions in high explosive trains, such as at detonators to explosive columns, field joints in explosive columns, and components of munitions fuse trains are demostrated. Reliability of detonation transfer is limited by minimizing explosive quantities, the use of intensitive explosives for safety, and requirements to propagate across gaps and angles dictated by installation and production restraints. The major detonation transfer variables studied were: explosive quanity, sensitivity, and thickness, and the separation distances between donor and acceptor explosives.

Schimmel, M. L.

1973-01-01

337

Explosives characterization in terahertz range  

NASA Astrophysics Data System (ADS)

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

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

2011-10-01

338

The heterogeneous explosive reaction zone  

SciTech Connect

The calculated reaction zone of PBX-9404 using solid HMX Arrhenius kinetics is stable to perturbations. The calculated reaction zone Von Neumann spike pressure agrees with the experimental observations within experimental uncertainty associated with different experimental techniques. The calculated homogengeous explosive reaction zone thickness is larger than observed for the heterogeneous explosive. The effect of two volume percent air holes on the reaction zone was modeled using the three-dimensional Eulerian reactive hydrodynamic code, 3DE. The air holes perturb the reaction zone. A complicated, time-dependent, multidimensional reaction region proceeds through the heterogeneous explosive. The experimentally observed reaction zone characteristic of heterogeneous explosives are mean values of an irregular, three-dimensional reaction region. 20 refs., 6 figs.

Mader, C.L.; Kershner, J.D.

1989-01-01

339

Characterization of Commercial, Composite Explosives.  

National Technical Information Service (NTIS)

The explosive performance of a number of commercial blasting agents was investigated. EOS detonation parameters for a typical dynamite, aluminized and non-aluminized blasting agents, and ammonium nitrate/fuel oil (ANFO) were determined. The investigation ...

M. Finger F. Helm E. Lee R. Boat H. Cheung

1976-01-01

340

Ammunition Disassembly and Explosive Sectioning.  

National Technical Information Service (NTIS)

Remote control methods were developed to disassemble 40-mm ammunition. The projectiles were pulled from the cartridge cases, fuzes were removed from the projectiles, and explosive components were sectioned. Operations were performed remotely and monitored...

D. Boudreau C. J. Dahn R. Naylor

1984-01-01

341

Performance evaluation of insensitive explosives.  

National Technical Information Service (NTIS)

A calculational and experimental approach is described for characterizing explosive performance using quantities of 50-100 g. Thermochemical calculations are used to estimate the energy released for the isentropic expansion of the detonation products. LLN...

R. L. Simpson, J. W. Kury, A. L. Nichols, R. D. Breithaupt, P. C. Crawford

1991-01-01

342

Recent Combined Effects Explosives Technology.  

National Technical Information Service (NTIS)

Eigenvalue detonation theory has been shown to explain the observed behavior of new aluminized combined effects explosives. An analytical cylinder test model has long been used the U.S. Army Armaments Research, Development and Engineering Center, Picatinn...

C. Capellos, D. Murphy, D. Suarez, E. L. Baker, P. Cook

2010-01-01

343

Explosive plane-wave lens  

DOEpatents

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

Marsh, S.P.

1988-03-08

344

JiTT - Cambrian Explosion  

NSDL National Science Digital Library

1) How do scientists come up with the number 2 billion years ago for the first branch of life? Explain the dating technique and information that is used. 2) Describe the evidence AGAINST the Cambrian Explosion. ...

Guertin, Laura

345

Slifer Measurement for Explosive Yield.  

National Technical Information Service (NTIS)

This report describes the shorted location indicator by frequency of electrical resonance (SLIFER) system used at Sandia Laboratories for determination of explosive yield of under ground nuclear tests. (ERA citation 01:017194)

B. C. Benjamin D. R. Breding H. M. Miller R. C. Bass

1976-01-01

346

Explosive plane-wave lens  

DOEpatents

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

Marsh, S.P.

1987-03-12

347

Preventing Large-Battery Explosions.  

National Technical Information Service (NTIS)

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 Safet...

D. Cummins S. F. Pangerl

1980-01-01

348

Explosibility of Australian Wheat Dusts.  

National Technical Information Service (NTIS)

The purpose of the investigation was to assess the explosive characteristics of the dusts produced from various grades of wheat grown in Australia. Dust samples were collected at country silos and export terminals for wheat grown in northern and southern ...

R. J. Enright M. H. Bullock

1983-01-01

349

Explosive Spot Joining of Metals  

NASA Technical Reports Server (NTRS)

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

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

1997-01-01

350

Explosion modelling for complex geometries  

NASA Astrophysics Data System (ADS)

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.

Nehzat, Naser

351

Energy transfer in solid explosives  

Microsoft Academic Search

The nonequilibrium Zeldovich-von Neumann-Doring theory of detonation in solid explosives is extended to include recent nanosecond and picosecond experimental and theoretical results on each of the four main regions of the reaction zone. The first region is the three-dimensional, Mach stem dominated leading shock front which excites the phonon modes of the explosive molecules in less than a picosecond. The

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

1993-01-01

352

Thermodynamic States in Explosion Fields  

Microsoft Academic Search

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

Kuhl

2009-01-01

353

Net Catches Debris From Explosion  

NASA Technical Reports Server (NTRS)

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

Kahn, Jon B.; Schneider, William C.

1992-01-01

354

Explosive vaporization of small droplets  

SciTech Connect

A model has been created of the explosive vaporization of small droplets by the absorption of energy from a high energy laser beam. The model consists of a polarizable drop of fluid interacting with laser radiation. A criterion for the explosion of the droplet has been introduced. Selfsimilarity is invoked to reduce the spherically symmetric problem involving hydrodynamics and Maxwell's equations to simple quadrature. Experimental evidence in favor of the model is cited.

Chitanvis, S.M.

1986-08-19

355

Steam explosion research at Sandia  

SciTech Connect

Based upon current analysis of a specific PWR and experimental results, generation of large mass missiles by a steam explosion is unlikely, while small mass missiles, although more likely, probably would not pose a threat to the containment. The conservative upper bound probability of containment failure due directly to steam explosions is estimated to be no greater than 0.01 while the best estimate value is probably two orders of magnitude smaller.

Berman, M.; Corradini, M.L.; Mitchell, D.E.; Nelson, L.S.

1980-01-01

356

System for analysis of explosives  

DOEpatents

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

Haas, Jeffrey S. (San Ramon, CA) [San Ramon, CA

2010-06-29

357

Explosivity Conditions of Aqueous Solutions  

Microsoft Academic Search

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

R. Thiry; L. Mercury

2009-01-01

358

Explosive actuated valve  

DOEpatents

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.

Byrne, Kenneth G. (Livermore, CA)

1983-01-01

359

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

SciTech Connect

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 EGDNNO3- 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 DMNBNO2- and 1.44 cm2 V-1s-1 for DMNBNH4+. Positive ions for cyclohexanone were also apparent in the spectra from tagged C-4 producing three additional peaks.

Ewing, Robert Gordon; Miller, Carla Jean

2001-11-01

360

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

Federal Register 2010, 2011, 2012, 2013

...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...

2012-09-06

361

Engineering Design Handbook: Explosives Series Properties of Explosives of Military Interest.  

National Technical Information Service (NTIS)

The report is one of a series on Explosives. One hundred and ten explosive compounds or mixtures are listed alphabetically, with their properties, including composition variations. These explosives were selected because of their current or probable applic...

1971-01-01

362

Fundamental microstructural issues associated with severe plastic deformation: Applications of transmission electron microscopy  

Microsoft Academic Search

This study deals with the microstructural response of several metals and alloys to severe plastic deformation (SPD) in the form of shock wave loading, impact cratering, explosive welding, and ballistic penetration. Microstructural issues that will be addressed include dynamic recrystallization, adiabatic shear bands, and microbands and microtwins. Other relevant issues are stacking fault free energy (SFE), shock wave geometry and

Erika Vanessa Esquivel

2005-01-01

363

Dependence of Plastic TATB Shock-Wave Sensitivity on Temperature, Density and Technology Factors  

Microsoft Academic Search

Mixed TATB-based HE is the most perspective because of the manufacture and exploitation safety of its items. At the same time the safety of these explosive, at high temperatures, which take place at emergencies, causes the certain anxiety. Plastic TATB shock-wave sensitivity (SWS) researches has shown that temperature as one of the important factors of external influence is not always

Yu. A. Vlasov; V. B. Kosolapov; L. V. Fomicheva; I. P. Khabarov

1999-01-01

364

Developmental plasticity in plants.  

PubMed

As sessile organisms, plants are unable to seek out environmental conditions optimal for their growth and development but instead must complete their life cycles in the environment in which they are growing. However, plants are remarkably plastic, such that a single genotype is able to give rise to a wide range of phenotypes. Developmental plasticity has profound implications for plant evolution and ecology and can make important contributions to improving yield stability in agriculture. In this review, we discuss the genetic control mechanisms that underlie plasticity and their implications for plant evolution, using the control of flowering time in Arabidopsis as an example. Furthermore, we consider how rapid improvements in quantitative genetic resources provide opportunities to analyze the molecular mechanisms that regulate developmental plasticity more directly and completely. PMID:23250989

de Jong, M; Leyser, O

2012-01-01

365

Introduction to Plastics  

NSDL National Science Digital Library

Teachers' Domain presents this video as part of a series on advanced technological education. This video illustrates the basics of the plastics industry. The clip teaches the physical properties of plastics, including examples of common plastics. It also includes an animation depicting how monomers join to form polymers, which plastics are made up of. The video goes on to show how polymers and resins are produced. The video may be viewed online or downloaded. To download the clip, users must create a free login for Teachers' Domain. Running time for this QuickTime video is 2:36. Educators will also find a background essay, discussion questions, and standards alignment for the material.

2010-09-29

366

A Plastic Menagerie  

ERIC Educational Resources Information Center

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.)

Hadley, Mary Jane

2010-01-01

367

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.

2000-01-01

368

Thermodynamic States in Explosion Fields  

SciTech Connect

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.

Kuhl, A L

2009-10-16

369

PLASTICIZER RETENTION IN PVC GEOMEMBRANES  

Microsoft Academic Search

Plasticizers are used to make PVC flexible so it can be used as a geomembrane for containment purposes. Plasticizers can migrate from PVC geomembranes over time because of contact with air, liquid, and an absorbent solid material. Plasticizer migration can reduce the flexibility of PVC geomembranes. This paper discusses the three mechanisms of plasticizer migration and the factors influencing these

T. D. Stark; H. Choi; P. W. Diebel

370

Plastic Bullets - A Reasonable Force.  

National Technical Information Service (NTIS)

Why do the police need plastic bullets. The police themselves give two reasons. First, plastic bullets keep stone-throwers out of range. Secondly, firing plastic bullets will disperse a crowd. Plastic bullets work by causing pain, or the fear of pain, res...

J. Rosenhead

1985-01-01

371

Insensitive fuze train for high explosives  

DOEpatents

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

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

1994-01-04

372

Insensitive fuze train for high explosives  

DOEpatents

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

Cutting, Jack L. (Livermore, CA); Lee, Ronald S. (Livermore, CA); Von Holle, William G. (Livermore, CA)

1994-01-01

373

Experimental measurements of the detonation wave profile in a TATB based explosive  

NASA Astrophysics Data System (ADS)

We report results of the experimental measurements of the detonation wave profile of the TATB based plastic bonded explosive T2 (97 w. % of TATB) using VISAR and Heterodyne Velocimetry (HV - same as Photon Doppler Velocimetry). The experiment consists in initiating a detonation wave in a 15 mm diameter cylinder of explosive using an explosive wire detonator and an explosive booster. In order to obtain the particle velocity history in the reaction zone, we measure particle velocity at the interaction of the detonation front with an aluminized window or the free surface velocity of a metallic foil. Lithium Fluoride (LIF), PMMA and steel have been tested. Several shots have been performed for different lengths of explosive. We compare the VISAR and HV measurements. With LIF and steel, VISAR and HV diagnostics give very similar profiles. The ZND profile obtained on LIF is resolved with both techniques. With PMMA, HV gives a more accurate profile than VISAR in the reaction zone. There is no evidence of the influence of the explosive cylinder length.

Bouyer, V.; Doucet, M.; Decaris, L.

374

The Quiet Explosion  

NASA Astrophysics Data System (ADS)

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

2008-07-01

375

Optimal dynamic detection of explosives  

SciTech Connect

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.

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

376

Evidence for nearby supernova explosions.  

PubMed

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

Bentez, Narciso; Maz-Apellniz, Jess; Canelles, Matilde

2002-02-25

377

Permeability enhancement using explosive techniques  

SciTech Connect

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.

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

1980-01-01

378

Design of explosive logic elements  

SciTech Connect

Los Alamos has been exploring explosive logic systems to see if they might provide advantages in weapon safety or weapon command and control. We use the extrudable explosive EXTEX (80% PETN, 20% Sylgard) for this work. These systems contain at least one but usually several discrete logic elements, and the worth - the reliability - of the system is directly dependent on the reliability of these elements. We perceive that the troubles encountered in the early attempts to use explosive logic can be attributed to the lack of a truly reliable design for one or more of the elements being used. At Los Alamos, we express this as the need for a Safety/Reliability Window. In this short presentation, that concept will be emphasized. The development of three elements for which working windows are available will be discussed.

Meyers, W.H.

1984-01-01

379

The Most Powerful Stellar Explosions  

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

380

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

NASA Technical Reports Server (NTRS)

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.

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

1985-01-01

381

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

NASA Astrophysics Data System (ADS)

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 200400 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.

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

2013-11-01

382

Lightning Protection for Explosive Facilities  

SciTech Connect

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?

Ong, M

2001-12-01

383

Explosive blasting method and means  

SciTech Connect

An explosive blasting method and apparatus are claimed for producing rock fragmentation and reducing the amplitude of seismic effects (ground vibration) in the vicinity of the blast. It utilizes an air gap method and apparatus for superheating the air surrounding the charge in a borehole. This raises the pressure therein coupled with the use of multiple detonation points along the borehole for the reduction of burn time. This reduces the quantity of explosives used along with a marked reduction of seismic shock, sound, and dust effects to the surrounding area.

Bowling, D.S.; Moore, R.N.

1983-05-10

384

Experiments in gasdynamics of explosions.  

NASA Technical Reports Server (NTRS)

Various topics concerning recent accomplishments in experimental studies of gasdynamics of explosions are reviewed. Detonations, shocks, and blast waves form these topics. The most important feature of current studies is the particular attention paid to transient processes and the concomitant progress made in the development of novel experimental means for the study of such processes. The most exciting prospects for the future are associated with possibilities of exploiting knowledge of explosion phenomena for the development of such interesting devices as the gasdynamic laser and the apparatus based on the use of lasers to achieve controlled thermonuclear reaction.

Oppenheim, A. K.; Soloukhin, R. I.

1973-01-01

385

Coulomb Explosion and Thermal Spikes  

NASA Astrophysics Data System (ADS)

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.

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

2002-04-01

386

Explosive coalescence of magnetic islands  

NASA Technical Reports Server (NTRS)

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.

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

1986-01-01

387

Explosive response model evaluation using the explosive H6  

Microsoft Academic Search

Reactive rate model parameters for a two term Lee Tarver [simplified ignition and growth (SIG)] model were obtained for the explosive H6 from modified gap test data. These model was used to perform simulations of the underwater sensitivity test (UST) using the CTH hydrocode. Reaction was predicted in the simulations for the same water gaps that reaction was observed in

Gerrit T. Sutherland; Joseph Burns

2000-01-01

388

29 CFR 1926.903 - Underground transportation of explosives.  

Code of Federal Regulations, 2013 CFR

...false Underground transportation of explosives. 1926.903 Section 1926.903...CONSTRUCTION Blasting and the Use of Explosives § 1926.903 Underground transportation of explosives. (a) All explosives or...

2013-07-01

389

30 CFR 56.6302 - Separation of explosive material.  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 false Separation of explosive material. 56.6302 Section 56.6302...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Use § 56.6302 Separation of explosive material. Explosives and blasting...

2013-07-01

390

30 CFR 56.6305 - Unused explosive material.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Unused explosive material. 56.6305 Section 56.6305...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Use § 56.6305 Unused explosive material. Unused explosive material...

2013-07-01

391

30 CFR 57.6905 - Protection of explosive material.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Protection of explosive material. 57.6905 Section 57...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives General Requirements-Surface and Underground § 57.6905 Protection of explosive material. (a) Explosive...

2013-07-01

392

30 CFR 57.6903 - Burning explosive material.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Burning explosive material. 57.6903 Section...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives General Requirements-Surface and Underground § 57.6903 Burning explosive material. If explosive...

2013-07-01

393

30 CFR 56.6903 - Burning explosive material.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Burning explosive material. 56.6903 Section 56...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives General Requirements § 56.6903 Burning explosive material. If explosive material...

2013-07-01

394

30 CFR 57.6305 - Unused explosive material.  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 false Unused explosive material. 57.6305 Section 57...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives Transportation-Surface and Underground § 57.6305 Unused explosive material. Unused explosive...

2013-07-01

395

30 CFR 56.6905 - Protection of explosive material.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Protection of explosive material. 56.6905 Section 56...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives General Requirements § 56.6905 Protection of explosive material. (a) Explosive...

2013-07-01

396

30 CFR 57.6302 - Separation of explosive material.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Separation of explosive material. 57.6302 Section...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives Transportation-Surface and Underground § 57.6302 Separation of explosive material. Explosives and...

2013-07-01

397

Review of Large Scale and Small Scale Underwater Thermal Explosions.  

National Technical Information Service (NTIS)

This report contains a review of large scale propagating thermal explosions and small scale single drop explosions. The review of large scale propagating thermal explosions identifies potential thermal explosive systems, as well as the experimental condit...

M. Rizk

1990-01-01

398

30 CFR 57.6102 - Explosive material storage practices.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Explosive material storage practices. 57.6102 Section 57...METAL AND NONMETAL MINES Explosives Storage-Surface and Underground § 57.6102 Explosive material storage practices. (a) Explosive...

2013-07-01

399

Modeling of Explosive Densensitization by Preshocking.  

National Technical Information Service (NTIS)

Densensitization of heterogeneous explosives by shocks too weak to initiate propagating detonation occurs because the preshock desensitizes the heterogeneous explosive by closing the voids and making it more homogeneous. A higher pressure second shock has...

C. L. Mader

1986-01-01

400

Sandia Explosive Inventory and Information System  

SciTech Connect

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.

Clements, D.A.

1994-08-01

401

Spot Test Kit for Explosives Detection.  

National Technical Information Service (NTIS)

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...

J. Del Eckels J. G. Reynolds P. F. Pagoria P. J. Nunes R. E. Whipple

2005-01-01

402

Taggants with Explosive Induced Magnetic Susceptibility.  

National Technical Information Service (NTIS)

This application discloses a color-coded taggant for the post-detonation identification of explosive material. Retrieval of the taggant after detonation of an explosive is facilitated by the addition of nickel formate to the taggant. The additive renders ...

C. Boyars

1980-01-01

403

Explosive Remnants of War in Stability Operations.  

National Technical Information Service (NTIS)

Explosive Remnants of War (ERW) are a global problem significantly contributing to instability throughout the undeveloped and developing-world. ERW also become a primary component used in Improvised Explosive Device (IED) fabrication across the globe, whi...

D. L. Cummings

2012-01-01

404

Explosives Safety Training Yesterday, Today and Tomorrow.  

National Technical Information Service (NTIS)

Concerns for explosives safety and explosives safety training are not new. These concerns date back to the days of black powder when manufacturers were made to locate their facilities away from populated areas. Of course, this action usually occurred only...

J. W. Gray

1994-01-01

405

Explosives Safety Distances for Hardened Aircraft Shelters.  

National Technical Information Service (NTIS)

This report is about explosives safety distances and risk management. Explosives safety distances are designed to protect people, facilities, and equipment against an inadvertent detonation of a friendly weapon; therefore, these distances reflect the perc...

R. C. Rhye

1988-01-01

406

Structure/Property Correlations in Primary Explosives.  

National Technical Information Service (NTIS)

The long range objective of the present combined experimental and theoretical program is to develop a relationship between chemical structure and primary explosive behavior as a research tool for assessing the potential of primary explosives. The ability ...

C. M. Tarver T. C. Goodale M. Cowperthwaite

1976-01-01

407

The Relation of Batteries to Explosives.  

National Technical Information Service (NTIS)

All batteries contain chemical materials which can be made to explode under certain conditions. This report defines applicable explosives terminology and discusses these definitions in terms of explosives, thermal runaway and fires associated with aqueous...

C. Freeman

1980-01-01

408

High-Explosive Driven Crowbar Switch.  

National Technical Information Service (NTIS)

The patent application relates to a compact explosive driven switch for use as a low resistance, low inductance crowbar switch. A high-explosive charge extrudes a deformable conductive metallic plate through a polyethylene insulating layer to achieve a ha...

R. S. Dike R. W. Kewish

1974-01-01

409

High-Explosive Driven Crowbar Switch.  

National Technical Information Service (NTIS)

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

R. S. Dike R. W. Kewish

1976-01-01

410

The plasticity of clays  

USGS Publications Warehouse

(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.

Group, F. F.

1905-01-01

411

TeachingPlastics.org: Your Virtual Plastics Classroom  

NSDL National Science Digital Library

This site, operated by the American Plastics Council, has a huge amount of plastics resources for both teachers and students. The site is divided into two main sections. Hands On Plastics is geared primarily for middle and high school levels, and Hands On Plastics Jr. is better for elementary school. Educators will find many lesson plans and activities to help them introduce various topics, and they can order a free supplement kit with plastic products. Interactive multimedia walk-throughs of the activities show exactly what needs to be done and how to do it. There is also a large hyperlink list with information about many aspects of plastics.

2000-01-01

412

Experimental study of fuel-air explosive  

Microsoft Academic Search

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 36 m from the explosion center is definitely more pronounced than that of a TNT

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

2008-01-01

413

Explosive Vapor Detection Using Microcantilever Sensors  

Microsoft Academic Search

Explosive-based terrorism is an eminent threat to a civilized and free society. Accurate and cost-effective explosive sensors are, therefore, essential for combating the terrorist threat. Some of the main performance characteristics for explosive sensors include sensitivity, selectivity, and real-time fast operation. As the vapor pressures of commonly used explosives are extremely small, highly sensitive sensors are essential for detecting trace

Larry R Senesac; Thomas George Thundat

2007-01-01

414

Explosion welding and cutting in aerospace engineering  

NASA Astrophysics Data System (ADS)

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

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

415

Modeling initiation of explosives by projectile impact  

SciTech Connect

A shock initiation model was developed for the initiation of bare or clad explosives impacted by flat or hemispherical-tipped projectiles. The model requires Hugoniot data for the unreacted explosive, cladding material and projectile material, and the shock run distance to detonation as function of the shock pressure imparted to the explosive. Model results are compared to experimental data for flat and hemispherical-tipped steel projectiles impacting bare and clad PBX 9404 explosive.

Yactor, R.J.

1992-07-01

416

Modeling initiation of explosives by projectile impact  

SciTech Connect

A shock initiation model was developed for the initiation of bare or clad explosives impacted by flat or hemispherical-tipped projectiles. The model requires Hugoniot data for the unreacted explosive, cladding material and projectile material, and the shock run distance to detonation as function of the shock pressure imparted to the explosive. Model results are compared to experimental data for flat and hemispherical-tipped steel projectiles impacting bare and clad PBX 9404 explosive.

Yactor, R.J.

1992-01-01

417

Dust explosion hazard in ITER: Explosion indices of fine graphite and tungsten dusts and their mixtures  

Microsoft Academic Search

Addressing the dust explosion hazard in ITER, a standard method with a 20-l-spherical combustion chamber was used to measure the explosion indices of fine graphite and tungsten dusts and their mixtures. The indices include maximum overpressure, maximum rate of pressure rise, and lower explosion concentration limit. The effect of dust particle size was studied on the explosion behaviour of graphite

A. Denkevits; S. Dorofeev

2005-01-01

418

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

Microsoft Academic Search

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

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

2006-01-01

419

Development of the titanium structure in explosive collapse of thick-walled cylinders  

Microsoft Academic Search

The dependence of the titanium structure on the total deformation in the explosive collapse of thick-walled cylinders is studied.\\u000a It is shown that structure evolution as a whole and the critical parameters for the appearance of an unstable plastic flow\\u000a in titanium are not the functions of the final deformation of the cylinders. This instability, which is governed by the

M. P. Bondar; O. L. Pervukhina; V. F. Nesterenko; Ya. L. Lukyanov

1998-01-01

420

Empirical model for the temporally resolved temperatures of post-detonation fireballs for aluminized high explosives  

Microsoft Academic Search

A physics-based empirical model is developed to characterize the time varying temperature profile from post-detonation combustion. Fourier-transform infrared signatures are collected from field detonations of RDX-based aluminized high explosives surrounded by an aluminized plastic-bonded spin-cast liner. The rate of change of temperature in the postdetonation combustion fireballs are modeled using a radiative cooling term and a double exponential combustion source

J. M. Gordon; Kevin C. Gross; Glen P. Perram

2011-01-01

421

High-explosive properties from classical molecular dynamics simulations and quantum-chemical computations  

Microsoft Academic Search

We are using classical molecular dynamics and condensed phase electronic-structure methods to predict some of the thermophysical and mechanical properties that are needed as input to realistic mesoscale models for plastic-bonded explosives. The main materials studied to date are HMX, PETN, Estane copolymer, and bi(2,2-dinitropropyl) formal\\/acetal (BDNPF\\/A). Emphasis is placed on non-reactive properties and thermodynamic states relevant to cookoff and

T. D. Sewell; C. K. Gan; E. Jaramillo; A. H. Strachan

2004-01-01

422

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

Microsoft Academic Search

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 10⁴ s⁻¹. Experimental data indicate the development and growth of multiple plastic instabilities which appear in a quasi-periodic

Martineau

1998-01-01

423

Initiation of Heated PBX-9501 Explosive When Exposed to Dynamic Loading  

SciTech Connect

Shock initiation experiments on the heated PBX9501 explosive (95% HMX, 2.5% estane, and 2.5% nitro-plasticizer by weight) were performed at temperatures 150 C and 180 C to obtain in-situ pressure gauge data. A 101 mm diameter propellant driven gas gun was utilized to initiate the PBX9501 explosive and manganin piezo-resistive pressure gauge packages were placed between sample slices to measure time resolved local pressure histories. The run-distance-to-detonation points on the Pop-plot for these experiments showed the sensitivity of the heated material to shock loading. This work shows that heated PBX-9501 is more shock sensitive than it is at ambient conditions. Proper Ignition and Growth modeling parameters were obtained to fit the experimental data. This parameter set will allow accurate code predictions to be calculated for safety scenarios involving PBX9501 explosives at temperatures close to those at which experiments were performed.

Urtiew, P A; Vandersall, K S; Tarver, C M; Garcia, F

2005-08-16

424

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

PubMed

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

Cotte-Rodrguez, Ismael; Takts, Zoltn; Talaty, Nari; Chen, Huanwen; Cooks, R Graham

2005-11-01

425

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

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

426

Friction and impact sensitivities of explosives: A comparative study. [HMX, CP, barium styphnate, RX26BB, RX26BH, PYX, BTF  

Microsoft Academic Search

Impact and friction sensitivities of explosives were tested by the ''one-shot'' method. The Bruceton statistical method was used to derive 50% initiation levels. The materials tested include: PETN, HMX, CP, barium styphnate, TATB, RX26BB, RX26BH, PYX, BTF and various types of plastic bonded explosives (PBX). Some samples were investigated for aging effects, physical variables, and the effect of manufacturing parameters

Pu Sen Wang; G. F. Hall

1988-01-01

427

Involvement in plastic pipe  

SciTech Connect

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

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

1983-08-01

428

Consumer hazards of plastics.  

PubMed Central

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.

Wiberg, G S

1976-01-01

429

W-band imaging of explosive substances  

Microsoft Academic Search

This paper presents three-dimensional W-band images of some common explosives and substances that can be used to produce explosives. As an introduction, some information about the imaged materials (DUTs) is given. After a detailed description of the measurement setup, multiple views of the three dimensional image data are presented. Data features that could be used for detection of the explosives

Andreas Schiessl; Sherif Sayed Ahmed

2009-01-01

430

Modeling initiation of explosives by projectile impact  

Microsoft Academic Search

A shock initiation model was developed for the initiation of bare or clad explosives impacted by flat or hemispherical-tipped projectiles. The model requires Hugoniot data for the unreacted explosive, cladding material and projectile material, and the shock run distance to detonation as function of the shock pressure imparted to the explosive. Model results are compared to experimental data for flat

Yactor

1992-01-01

431

Method and apparatus for detecting explosives  

Microsoft Academic Search

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

David Steven

2011-01-01

432

CHEMICAL REACTIONS INDUCED BY UNDERGROUND NUCLEAR EXPLOSIONS  

Microsoft Academic Search

As part of the general program for study of potential industrial and ; civil applications of nuclear explosions (Plowshare Program), chemical reactions ; useful for the recovery of nuclear energy are discussed. Three problems are ; considered. First, the mechanism for the transfer of explosive energy to the ; medium is discussed and the results of calculations of useful explosive

G. H. Higgins; D. E. Rawson; W. Z. Wade

1961-01-01

433

Non?traditional explosives: Potential detection problems  

Microsoft Academic Search

Most explosive detection technologies have been focused on nitro?based military explosives because, indeed, they have figured in international terrorist incidents Not only are they readily available through purchase or theft or from sponsoring states, but methods for home synthesis of TNT, PETN and RDX are widely available. Presently substantial resources are being committed to developing explosive detection technologies to protect

Jimmie C. Oxley

1993-01-01

434

Non-ideal detonation of emulsion explosives  

Microsoft Academic Search

In order to obtain a better understanding of the underwater explosion phenomena related to emulsion explosives, optical measurements using the water tank technique and cylinder expansion test were carried out. Streak photographs were taken using an image converter camera with a usual shadow graph system. Four kinds of emulsion explosives differing in aluminium contents were used in the experiments. These

K Takahashi; K Murata; Y Kato; M Fujita; S Itoh

1999-01-01

435

63 FR 18104 - Explosives Detection Systems  

Federal Register 2010, 2011, 2012, 2013

...Testing (U) Testing of bulk/main explosive charges detection equipment presented...A General Testing Protocol for Bulk Explosives Detection Systems, (National Advisory...Technical Center in Atlantic City, New Jersey will perform certification tests for producers of candidate explosives detection systems. The EDS...

1998-04-13

436

61 FR 46011 - Explosives Detection Systems  

Federal Register 2010, 2011, 2012, 2013

...Testing (U) Testing of bulk/main explosive charges detection equipment presented...a General Testing Protocol for Bulk Explosives Detection Systems, (National Advisory...Technical Center in Atlantic City, New Jersey will perform certification tests for producers of candidate explosives detection systems. The EDS...

1996-08-30

437

Shock sensitivity of blasting explosive cartridges  

Microsoft Academic Search

The undersand variable gapinitiator test was applied to most Japanese blasting explosive cartridges and found useful as the sensitivity test for the cartridges. The recent Japanese watergel and emulsion explosives were shown to be more shocksensitive than previous ones. The blast noise in the undersand explosion was shown to decrease when the depth of sand cover the cartridge was increased.

Yuji Wada; Hideo Yabashi; Masamitsu Tamura; Tadao Yoshida; Toshio Matsuzawa; Fumio Hosoya

1991-01-01

438

Analysis of Picattiny Sample for Trace Explosives  

SciTech Connect

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.

Klunder, G; Whipple, R; Carman, L; Spackman, P E; Reynolds, J; Alcaraz, A

2008-05-23

439

Doping explosive materials for neutron radiographic enhancement.  

NASA Technical Reports Server (NTRS)

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.

Golliher, K. G.

1971-01-01

440

Controlling Simulated Explosions by Optimization and Prediction  

Microsoft Academic Search

This paper presents a method for controlling simulated explosions by prediction and optimization. Many methods have been proposed for simulating realistic explosion based on numerical fluid analysis. These methods are widely used in applications such as movies and computer games. In these applications, there is often a requirement for the explosion to conform to a specified final shape. The goal

Syuhei Sato; Yoshinori Dobashi; Tsuyoshi Yamamoto; Ken Anjyo

2011-01-01

441

Polymer sensors for nitroaromatic explosives detection  

Microsoft Academic Search

Several polymers have been used to detect nitroaromatic explosives by a variety of transduction schemes. Detection relies on both electronic and structural interactions between the sensing material and the analyte. Quenching of luminescent polymers by electron deficient nitroaromatic explosives, such as trinitrotoluene, may be monitored to detect explosives. Resistive sensing using carbon black particles that have been coated with different

Sarah J. Toal; William C. Trogler

2006-01-01

442

Surf Zone Explosive Channel Modeling.  

National Technical Information Service (NTIS)

The long-term goal of this project is to develop a reliable and robust predictive methodology of general applicability for predicting the sizes of craters and channels produced in the surf zone by underwater explosions of single bombs, lines of bombs, and...

S. Van Denk W. G. Szymczak

1998-01-01

443

ICPP custom dissolver explosion recovery  

Microsoft Academic Search

This report discusses the recovery from the February 9, 1991 small scale explosion in a custom processing dissolver at the Idaho Chemical Processing Plant. Custom processing is a small scale dissolution facility which processes nuclear material in an economical fashion. The material dissolved in this facility was uranium metal, uranium oxides, and uranium\\/fissium alloy in nitric acid. The paper explained

R. Demmer; R. Hawk

1992-01-01

444

ICPP custom dissolver explosion recovery  

Microsoft Academic Search

This paper discusses the recovery from the February 9, 1991, small scale explosion in a custom processing dissolver at the Idaho Chemical Processing Plant (ICPP) a Department of Energy facility at the Idaho National Engineering Laboratory. The custom processing facility is a limited production area designed to recover unirradiated uranium fuel. A small amount of the nuclear material received and

R. Demmer; R. Hawk

1992-01-01

445

Shock Initiation of Heterogeneous Explosives  

Microsoft Academic Search

The fundamental picture that shock initiation in heterogeneous explosives is caused by the linking of hot spots formed at inhomogeneities was put forward by several researchers in the 1950's and 1960's, and more recently. Our work uses the computer hardware and software developed in the Advanced Simulation and Computing (ASC) program of the U.S. Department of Energy to explicitly include

Reaugh

2004-01-01

446

Risperidone and Explosive Aggressive Autism.  

ERIC Educational Resources Information Center

In this study, 11 males with autism and mental retardation were administered risperidone. Substantial clinical improvement was noted almost immediately; patients with aggression, self-injury, explosivity, and poor sleep hygiene were most improved. The modal dose for optimal response was 0.5 mg bid. Weight gain was a significant side effect.

Horrigan, Joseph P.; Barnhill, L. Jarrett

1997-01-01

447

Advances in Explosive Train Technology.  

National Technical Information Service (NTIS)

The proper functioning of any munition system depends on the reliable initiation of successive elements in an explosive train and on the transfer of sufficient energy from one element to another so that the fuze ultimately detonates a main charge. Some of...

E. W. Dalrymple T. Costain W. E. Voreck

1974-01-01

448

GRANULAR EXPLOSIVES AND INITIATION SENSITIVITY  

Microsoft Academic Search

Fundamental chemical reaction rates are temperature depend. However, the initiation process for a hetero- geneous explosive is dominated by peaks in the temperature field called hot spots. Numerical simulations typically use empirical pressure dependent reaction rates. These can be viewed as a subgrid model that accounts for unresolved reaction phenomenon. The limitation of simple burn rates is most severe for

Ralph Menikoff

1999-01-01

449

Explosive pulsed electric power generation  

Microsoft Academic Search

A 5-year Multidisciplinary Research Initiative (MURI) program on generating high energy electric pulses from explosive generators is funded by the office of the Director of Defense Research and Engineering and monitored by the Air Force Office of Scientific Research. The program involves Texas Tech University (lead university), the University of Missouri at Rolla, Texas A&M University and The University of

M. Kristiansen; J. Gregor

2001-01-01

450

Episodic explosions in interstellar ices  

NASA Astrophysics Data System (ADS)

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

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

2013-03-01

451

Explosive Ordnance Disposal Protective Suit.  

National Technical Information Service (NTIS)

An explosive ordnance disposal protective suit which includes trousers, a coat with collar, a protective helmet and a combination face shield-chest plate. The face shield-chest plate is supported and held in place by a pocket on the front of the coat. The...

R. Martone

1984-01-01

452

Nuclear Explosion over the Taiga.  

National Technical Information Service (NTIS)

Data are reviewed suggesting that the mysterious body which exploded on 30 June 1908 in the Siberian taiga near the Tunguska River released nuclear energy and that the explosion was actually some sort of nuclear blast. An examination of previously establi...

F. Y. Zigel'

1964-01-01

453

The Rush to Explosive Clad  

Microsoft Academic Search

The manufacturing and process control steps used to produce explosively bonded clad metal plate are explained through a typical requirement for stainless steel heat exchanger components. Although the story is fictitious the details are daily events at Dynamic Materials Corp. The qualitative explanation gives insight into the well mastered manufacturing process. DMC's sister companies in Europe, Nobelclad, France and NitroMetall,

George A. Young

454

Soft container for explosive nuts  

NASA Technical Reports Server (NTRS)

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.

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

1981-01-01

455

Type IA Supernova Explosion Models  

Microsoft Academic Search

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

Wolfgang Hillebrandt; Jens C. Niemeyer

2000-01-01

456

Battery Explosion Tests and Labeling.  

National Technical Information Service (NTIS)

The six tasks outlined in the contract were reviewed and analyzed by SAE and resulted in the following: (1) Battery explosion test procedures and a criteria of pass-fail have been developed which are applicable for all lead-acid, automotive batteries. (2)...

1978-01-01

457

Plastic heliostat enclosure analysis  

NASA Astrophysics Data System (ADS)

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.

Berry, M. J.

1984-12-01

458

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

NASA Technical Reports Server (NTRS)

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

Mercado, AL; Marsden, Paul

1995-01-01

459

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)

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.

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

2012-02-01

460

Neural Plasticity in Schizophrenia  

Microsoft Academic Search

No current biological hypothesis can assimilate the genetic, environmental, and clinical features of schizophrenia. If, as some authors contend, environmental factors have important effects on the course of schizophrenia, then a fruitful research concern may be the adaptation of neuronal circuitry to environmental changes. The plasticity of neuronal connections has been studied by subjecting animals to neurosurgical lesions, brain electrostimulation,

John L. Haracz

1985-01-01

461

Plastic optical fibers  

Microsoft Academic Search

This paper deals with the analysis of the current POF market trends and its estimated growth in the vital sectors in the years to come. Plastic optical fibers have now come into the limelight since they have become an apparent middle ground between copper and glass optical fibers. The market area concerned is that where speed is at the high

Prerna Malhotra; Spurthi Astagi; Ketaki Kaluste

2010-01-01

462

Structural Ablative Plastics  

Microsoft Academic Search

Laminated reinforced plastics using carbon or silica fabrics and phenolic resins are widely used for ablative liners of rocket nozzles and for other applications requiring protection of structural elements in a high thermal environment. Under cyclic heating conditions, the phenolic resin chars, thereby providing ablation cooling; on cool-down, cracks and\\/or delaminations result in the majority of applications. On a reheat

Robert M. Lurie; Stephen F. Durso; Charles K. Mullen

1969-01-01

463

Dehydrochlorination of plastic mixtures  

Microsoft Academic Search

Dehydrochlorination of plastic mixtures from domestic waste as well as from other chlorine containing mixtures such as electronic scrap is an essential reaction step in waste incineration, pyrolysis and chemical recycling of polymers. For designing pyrolysis procedures, controlled combustion processes and to control the emissions from incinerators, the behaviour of polymers in thermal decomposition with regard to decomposition products and

H Bockhorn; A Hornung; U Hornung; P Jakobstrer; M Kraus

1999-01-01

464

Stem cell plasticity  

Microsoft Academic Search

The central dogma in stem cell biology has been that cells isolated from a particular tissue can renew and differentiate into lineages of the tissue it resides in. Several studies have challenged this idea by demonstrating that tissue specific cell have considerable plasticity and can cross-lineage restriction boundary and give rise to cell types of other lineages. However, the lack

Uma Lakshmipathy; Catherine Verfaillie

2005-01-01

465

Preserving in Plastic.  

ERIC Educational Resources Information Center

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)

Wahla, James

1985-01-01

466

Friction of plastic webs  

Microsoft Academic Search

This paper is about the measurement of the friction of plastic and similar flexible webs in contact with cylindrical surfaces. There are numerous ways for measuring friction coefficients of materials in relative contact, but to be meaningful, the testing technique should simulate the tribosystem of interest. The subject of this paper is the capstan friction test, which simulates the tribosystem

K. G Budinski

2001-01-01

467

Fused Plastic Wallet  

NSDL National Science Digital Library

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.

Centers, Oakland D.

2012-01-01

468

Dynamic captive plastic seal  

NASA Technical Reports Server (NTRS)

Fluoroplastic material held captive between valve sealing surfaces of 16 to 125 rms microinches provides zero leakage to a high-pressure line at high cryogenic temperatures, when the plastic material is subjected to sufficient stress. This sealing technique makes unnecessary the use of superfinished valve sealing surfaces.

Dryer, E. O.

1967-01-01

469

Synaptic plasticity and addiction  

Microsoft Academic Search

Addiction is caused, in part, by powerful and long-lasting memories of the drug experience. Relapse caused by exposure to cues associated with the drug experience is a major clinical problem that contributes to the persistence of addiction. Here we present the accumulated evidence that drugs of abuse can hijack synaptic plasticity mechanisms in key brain circuits, most importantly in the

Julie A. Kauer; Robert C. Malenka

2007-01-01

470

Environmentally Degradable Plastics: A Review.  

National Technical Information Service (NTIS)

Reviewed are mechanisms for degrading plastics capable of being of being degraded, companies and universities engaged in the degradation technology, costs, suggested applications, military problems with degradable plastics and the future outlook for degra...

J. B. Titus

1973-01-01

471

Hazards of explosives dusts: Particle size effects  

NASA Astrophysics Data System (ADS)

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

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

1992-02-01

472

Treatment of materials by explosive energy  

SciTech Connect

Fundamental studies and applied developments in the treatment of materials by explosive energy, carried out at the Institute of Hydrodynamics and the Special Design Bureau of Hydroshock Technology of Siberian Branch of the Academy of Sciences of the USSR, are reviewed. Those studies and developments have taken place in the areas of explosive strengthening, explosive welding, and explosive powder compaction. The strengthening of high-manganese steel and other materials, railroad frogs, and explosive heat treatment are discussed. The physicomechanical aspects, metallography, and applications of explosive welding are assessed, using nickel superalloys and stainless steels as specific examples. The effects of explosive shock treatments on the structure and mechanical properties of alloy and powder materials were addressed.

Deribas, A.A.

1988-03-01

473

Explosive events on the Sun.  

PubMed

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

Harra, Louise K

2002-12-15

474

HOW PLASTIC IS YOUR LIME?  

Microsoft Academic Search

A case history is described in which a weathered, non-durable, basalt proposed for base course for the Trans - Caprivi Highway in the wettest area of Namibia could not be reduced to non-plastic with SANS 824-quality lime during construction as required, even after extended curing. Adding more lime simply increased the plasticity index. It was established that the excess plasticity

F. Netterberg

475

Extruding plastic scintillator at Fermilab  

Microsoft Academic Search

An understanding of the costs involved in the production of plastic scintillators and the development of a less expensive material have become necessary with the prospects of building very large plastic scintillation detectors. Several factors contribute to the high cost of plastic scintillating sheets, but the principal reason is the labor-intensive nature of the manufacturing process. In order to significantly

Anna Pla-Dalmau; Alan D. Bross; Victor V. Rykalin

2003-01-01

476

Plastics for Elementary School Children  

ERIC Educational Resources Information Center

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

Hanson, Jack

1977-01-01

477

Plastic Yielding at Crack Tips.  

National Technical Information Service (NTIS)

Small scale plastic yielding at crack tips is studied by means of nonlocal elasticity. Plastic lines along the crack line of Mode III crack are modelled by an array of dislocations. It is shown that plastic yield begins after a definite value of load, as ...

S. B. Altan A. C. Eringen

1988-01-01

478

Brain plasticity in paediatric neurology  

Microsoft Academic Search

Plasticity includes the brain's capacity to be shaped or moulded by experience, the capacity to learn and remember, and the ability to reorganize and recover after injury. Mechanisms for plasticity include activity-dependent refinement of neuronal connections and synaptic plasticity as a substrate for learning and memory. The molecular mechanisms for these processes utilize signalling cascades that relay messages from synaptic

Michael V Johnston

2003-01-01

479

Occupational hazards in plastic surgery  

Microsoft Academic Search

The occurrence of occupational disorders among plastic surgeons has not had much attention in the literature thus far. A case of a plastic surgeon with distal interphalangeal arthrosis, considered to represent an occupational disorder, is presented. In a review of the literature, possible occupational hazards in plastic surgery are discussed.

J. J. Hage; H. M. Suliman; J. Verhagen; F. G. Bouman

1995-01-01

480

Ranchero Explosive Pulsed Power Experiments  

SciTech Connect

The authors are developing the Ranchero high explosive pulsed power (HEPP) system to power cylindrically imploding solid-density liners for hydrodynamics experiments. The near-term goal is to conduct experiments in the regime pertinent to the Atlas Capacitor bank. That is, they will attempt to implode liners of {approximately}50 g mass at velocities approaching 15 km/sec. The basic building block of the HEPP system is a coaxial generator with a 304.8 mm diameter stator, and an initial armature diameter of 152 mm. The armature is expanded by a high explosive (HE) charge detonated simultaneously along its axis. They have reported a variety of experiments conducted with generator modules 43 cm long and have presented an initial design for hydrodynamic liner experiments. In this paper they give a synopsis of their first system test, and a status report on the development of a generator module that is 1.4 m long.

Goforth, J.H.; Atchison, W.L.; Deninger, W.J.; Fowler, C.M.; Herrera, D.H.; King, J.C.; Lopez, E.A.; Oona, H.; Reinovsky, R.E.; Stokes, J.L.; Sena, F.C.; Tabaka, L.J.; Tasker, D.G.; Torres, D.T.; Lindemuth, I.R.; Faehl, R.J.; Keinigs, R.K.; Taylor, A.J.; Rodriguez, G.; Oro, D.M.; Garcia, O.F.; parker, J.V.; Broste, W.B.

1999-06-27

481

Explosives detection system and method  

DOEpatents

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.

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

482

Applying NASA's explosive seam welding  

NASA Astrophysics Data System (ADS)

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.

Bement, Laurence J.

1991-12-01

483

Waves from an underground explosion  

NASA Astrophysics Data System (ADS)

The problem of the propagation of a spherical detonation wave in water-saturated soil was solved in [1, 2] by using a model of a liquid porous multicomponent medium with bulk viscosity. Experiments show that soils which are not water saturated are solid porous multicomponent media having a viscosity, nonlinear bulk compression limit diagrams, and irreversible deformations. Taking account of these properties, and using the model in [2], we have solved the problem of the propagation of a spherical detonation wave from an underground explosion. The solution was obtained by computer, using the finite difference method [3]. The basic wave parameters were determined at various distances from the site of the explosion. The values obtained are in good agreement with experiment. Models of soils as viscous media which take account of the dependence of deformations on the rate of loading were proposed in [4 7] also. In [8] a model was proposed corresponding to a liquid multicomponent medium with a variable viscosity.

Krymskii, A. V.; Lyakhov, G. M.

1984-05-01

484

Photographic laboratory studies of explosions.  

NASA Technical Reports Server (NTRS)

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.

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

1973-01-01

485

Electromagnetic Effects in SDF Explosions  

Microsoft Academic Search

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

H Reichenbach; P Neuwald; A L Kuhl

2010-01-01

486

Explosive shielding by weak layers  

SciTech Connect

This paper presents the results of a series of computations which were carried out to determine the effect that a layer of extremely weak rock embedded in an otherwise strong rock matrix would have on the displacements and velocities which result from the detonation of a nearby explosive source. The motivation for the study was the apparently different measurements obtained on the Mission Cyber Nuclear Event when compared to results obtained from other events of equal yield in similar geologic media.

Fourney, W.L.; Dick, R.D.; Weaver, T.A.

1993-01-01

487

Explosive shielding by weak layers  

SciTech Connect

This paper presents the results of a series of computations which were carried out to determine the effect that a layer of extremely weak rock embedded in an otherwise strong rock matrix would have on the displacements and velocities which result from the detonation of a nearby explosive source. The motivation for the study was the apparently different measurements obtained on the Mission Cyber Nuclear Event when compared to results obtained from other events of equal yield in similar geologic media.

Fourney, W.L.; Dick, R.D.; Weaver, T.A.

1993-02-01

488

Risperidone and Explosive Aggressive Autism  

Microsoft Academic Search

Many autistic patients with mental retardation have difficulties with explosivity and aggression. They often prove resistant to various pharmacotherapeutic interventions. In this study, 11 male outpatients (mean 18.3 years) were administered risperidone in an open-label fashion. The risperidone was started at 0.5 mg daily, and titrated upwards until maximum clinical benefit occurred. Serial clinical interviews were conducted, and Conners Parent-Teacher

Joseph P. Horrigan; L. Jarrett Barnhill

1997-01-01

489

Splicing Wires Permanently With Explosives  

NASA Technical Reports Server (NTRS)

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

Bement, Laurence J.; Kushnick, Anne C.

1990-01-01

490

Wave formation in explosive welding  

Microsoft Academic Search

The interface between explosively welded metals frequently exhibits a regular wave-like profile. The circumstances under which such a profile develops are not fully understood, and existing theories fail to predict some of its observed characteristics.In the present paper it is suggested that the principal features of wave-like welds are consistent with a mechanism in which the waves arise as a

J. N. Hunt

1968-01-01

491

How explosive are volcanic eruptions?  

NASA Astrophysics Data System (ADS)

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.

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

2009-12-01

492

The Physics of Nova Explosions  

NASA Astrophysics Data System (ADS)

A nova outburst is the consequence of the accretion of hydrogen rich material onto a white dwarf and is the largest hydrogen powered explosion in the Universe. The fuel is supplied by the secondary star in a close binary system while the strong electron degeneracy of the massive white dwarf acts as a container for the gas during the early stages of the explosion. Because the gas cannot expand until nearly the peak of the explosion, the temperature in the nuclear burning region will exceed 10^8K under all circumstances. As a result a major fraction of the CNO nuclei in the envelope are transformed into ?^+-unstable nuclei. I will discuss the effects on the evolution of the presence of these nuclei in the thermonuclear burning region. Recent observational studies have shown that there are two classes of novae; one which occurs on a white dwarf with a core composition of carbon and oxygen, and a second class that occurs on a white dwarf with a core consisting of oxygen, neon, and magnesium. In my talk I will concentrate on the latter class since these novae are predicted to produce the most interesting nucleosynthesis. I will report on hydrodynamic calculations that examine the consequences of the accretion process on 1.0M_solar, 1.25M_solar, and 1.35M_solar white dwarfs and which predict that novae can produce ^22Na, ^26Al, and other intermediate mass nuclei in interesting amounts. I will then discuss the results of new observational determinations of nova abundances which demonstrate that the predicted nucleosynthesis is occurring in the explosion. Finally, I will present the results of recent calculations, done with updated nuclear reaction rates and opacities, and discuss the causes of the quantitative differences with respect to published work.

Starrfield, Sumner

1996-05-01

493

Adipose tissue plasticity from WAT to BAT and in between.  

PubMed

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

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

2014-03-01

494

Vesiculation and basaltic explosive volcanism  

NASA Astrophysics Data System (ADS)

Basaltic explosive volcanism takes place over a range of scales from weak Strombolian discrete explosions to Plinian eruptions of moderate intensity (103-107 kg-s-1. Vesicles (and microlite) populations are sensitive indications of complex conduit processes in most of these basaltic eruptions, implying a delicate balance between mechanical coupling and uncoupling of the gas phase from the rising melt. Bubble number densities vary from 102 to 108 bubbles per cm3 reflecting contrasting rates of decompression scaling with eruptive intensity. During Strombolian eruptions, the conduit contains a complex mixture of fluid phases: slugs of uncoupled large bubbles, newly arrived, vesiculating melt accompanying the gas slugs, more mature melt resident in the conduit through the passage of multiple gas slugs, and populations of smaller gas bubbles that show variable degrees of mechanically coupling to the melt phases. This heterogeneity is present on time scales as short as single explosions but the proportions of the phase shift on time scales of days to months, reflecting the relative timing and size of gas slugs. Studied Plinian melts (e.g., Tarawera 1886, Etna 122 BC) contain significantly larger numbers of markedly smaller bubbles and a conspicuous population of microlites. The microlites play a key role in modifying effective viscosity of the melt phase which feeds back to promote disequilibrium degassing and "closed system' behavior.

Houghton, B. F.; Sable, J. E.; Lautze, N. C.

2006-12-01

495

Energy transfer in solid explosives  

SciTech Connect

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

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

1993-07-01

496

Thermodynamic States in Explosion Fields  

SciTech Connect

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.

Kuhl, A L

2010-03-12

497

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

NASA Technical Reports Server (NTRS)

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 i