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1

27 CFR 555.180 - Prohibitions relating to unmarked plastic explosives.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

2

27 CFR 555.180 - Prohibitions relating to unmarked plastic explosives.  

Code of Federal Regulations, 2010 CFR

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

2009-04-01

3

27 CFR 555.180 - Prohibitions relating to unmarked plastic explosives.  

Code of Federal Regulations, 2011 CFR

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

2011-04-01

4

27 CFR 555.180 - Prohibitions relating to unmarked plastic explosives.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

5

27 CFR 555.181 - Reporting of plastic explosives.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 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...

2010-04-01

6

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

7

27 CFR 555.181 - Reporting of plastic explosives.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2010-04-01 true 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...

2011-04-01

8

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

9

Thermally stable, plastic-bonded explosives  

DOEpatents

By use of an appropriate thermoplastic rubber as the binder, the thermal stability and thermal stress characteristics of plastic-bonded explosives may be greatly improved. In particular, an HMX-based explosive composition using an oil-extended styrene-ethylenebutylene-styrene block copolymer as the binder exhibits high explosive energy and thermal stability and good handling safety and physical properties.

Benziger, Theodore M. (Santa Fe, NM)

1979-01-01

10

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

11

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

Code of Federal Regulations, 2010 CFR

... 2009-04-01 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,...

2009-04-01

12

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

13

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

Code of Federal Regulations, 2011 CFR

... 2010-04-01 true 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,...

2011-04-01

14

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

15

Dynamic Mechanical Analysis of Plastic Bonded Explosives  

Microsoft Academic Search

Aging processes that change the mechanical properties of the binder of plastic bonded explosives (PBX) could have a significant effect on the composite mechanical properties. It is essential to understand how the binder ages; however, it is more realistic to test the change of mechanical properties of aging PBX. Because PBX's and Mocks have only a small amount of binder,

Mary S. Campbell

16

Microstructural Characterization of Plastic Bonded Explosives  

Microsoft Academic Search

Plastic bonded explosives (PBX), a mixture of hard, anisotropic grains in a compliant matrix, represent an interesting case for understanding composite mechanical response and failure. PBX 9501 (0.95 cyclotetramethylene tetranitramine [HMX], 0.05 polymer binder) is relatively safe formulation of HMX, which is thought to be due to the high compliance of the binder. Crack formation between the crystals and the

John Yeager; Daniel Hooks; David Bahr

2010-01-01

17

Microscopical examination of plastic-bonded explosives  

SciTech Connect

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

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

1997-10-01

18

Decomposition of Nitroplasticizer in Plastic Bonded Explosive PBX 9501  

Microsoft Academic Search

In the plastic bonded explosive PBX 9501, a 50\\/50 mixture of Estane 5703 (a polyester urethane random copolymer) and nitroplasticizer (NP) binds the HMX explosive crystals. Chemical kinetic mechanisms are being developed for the thermal degradation of NP for high temperatures (explosions) and low temperatures (natural and accelerated aging studies). The goal of this work is to investigate reaction mechanisms

D. K. Pauler; J. D. Kress; J. M. Lightfoot; L. Woods; B. G. Russell

2006-01-01

19

Microstructural Characterization of Plastic Bonded Explosives  

NASA Astrophysics Data System (ADS)

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

Yeager, John; Hooks, Daniel; Bahr, David

2010-03-01

20

Compacting Plastic-Bonded Explosive Molding Powders to Dense Solids  

SciTech Connect

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

B. Olinger

2005-04-15

21

A parametric pressing study using a plastic-bonded explosive  

SciTech Connect

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

Hayden, D. J. (David J.); Maez, L. R. (Leland R.); Olinger, B. W. (Barton W.); Powell, S. J. (Sandra J.)

2002-01-01

22

Creep Testing Plastic-Bonded Explosives in Uniaxial Compression  

Microsoft Academic Search

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

F J Gagliardi; B J Cunningham

2008-01-01

23

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

24

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

25

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

National Technical Information Service (NTIS)

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 (PB...

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

1998-01-01

26

Detection of Plastic Explosive Traces in the Human Thermal Plume  

NASA Astrophysics Data System (ADS)

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

Gowadia, Huban A.; Settles, Gary S.

1998-11-01

27

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

NASA Astrophysics Data System (ADS)

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

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

2009-06-01

28

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

NASA Astrophysics Data System (ADS)

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

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

2009-06-01

29

Decomposition of Nitroplasticizer in Plastic Bonded Explosive PBX 9501  

NASA Astrophysics Data System (ADS)

In the plastic bonded explosive PBX 9501, a 50/50 mixture of Estane 5703 (a polyester urethane random copolymer) and nitroplasticizer (NP) binds the HMX explosive crystals. Chemical kinetic mechanisms are being developed for the thermal degradation of NP for high temperatures (explosions) and low temperatures (natural and accelerated aging studies). The goal of this work is to investigate reaction mechanisms using density functional electronic structure theory in addition to the data obtained from explosion and aging experiments. Very little is known of the mechanisms for the oxidation of polymers by oxidants other than molecular oxygen. As the first step in the aging of PBX 9501 in a low moisture and low oxygen environment, we propose that NP decomposes into oxidizing gases (NO2 and NO).

Pauler, D. K.; Kress, J. D.; Lightfoot, J. M.; Woods, L.; Russell, B. G.

2006-07-01

30

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

31

A Plastic Explosive-Degrading Enzyme  

NASA Astrophysics Data System (ADS)

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

Miller, Anne-Frances

2006-03-01

32

Taylor impact tests and simulations of plastic bonded explosives  

NASA Astrophysics Data System (ADS)

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

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

2012-03-01

33

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

34

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

Microsoft Academic Search

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

Caroline E. Burgess; James D. Woodyard; K. A. Rainwater; J. M. Lightfoot; B. R. Richardson

1998-01-01

35

Plastbundna Spraengaemnen. 1. Introduktion och Litteratursammanstaellning (Plastic Bonded Explosives. 1. Introduction and Survey of the Literature),  

National Technical Information Service (NTIS)

The report summarizes the accessible unclassified literature on plastic bonded explosives (PBX) and related items. It is based on literature up to 1987. A concise introduction is first given, followed by a survey of used explosives and polymer materials. ...

A. G. Nord M. Eriksson

1988-01-01

36

Decomposition of Nitroplasticizer in Plastic Bonded Explosive PBX 9501  

NASA Astrophysics Data System (ADS)

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

Pauler, Denise

2005-07-01

37

Transient Detonation Processes in a Plastic Bonded Explosive  

NASA Astrophysics Data System (ADS)

Experiments involving the transfer of detonation from small booster charges of PBXN-5 (95% HMX and 5% Viton A) into larger charges of various plastic-bonded explosives (PBXs) have produced some surprising results and have stimulated investigation into the factors governing observed responses. To understand these results, we conducted a series of tests with different miniature detonator-booster configurations using laser velocimetry to quantify the pressure pulse that is transmitted from the PBXN-5 booster. Models were used to determine the ideal explosive behavior for comparison with the measured results. The differences are interpreted as being due to transient behavior and late-time energy release from the booster charge. We characterize these behaviors as evidence of microdetonics, where we define microdetonics as the study of less-than-CJ detonation performance due to curvature and/or transient behavior. This provides useful insights into the fundamentals of the detonation process that can feed into advanced modeling approaches such as Detonation Shock Dynamics (DSD).

Thomas, Keith A.; Martin, Eric S.; Kennedy, James E.; Garcia, Ismael A.; Foster, Joseph C.

2002-07-01

38

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

Microsoft Academic Search

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

Craig M. Tarver; Jake G. Koerner

2007-01-01

39

Atomistic studies of RDX and FOX7 Based Plastic-Bonded explosives: molecular dynamics simulation  

Microsoft Academic Search

Molecular dynamics simulations were carried out to study the effects of interface interactions between a crystalline structure and a plastic bonded explosive (PBX) system. In this work, the hydroxyl-terminated polybutadiene (HTPB) represents the polymer, isophorone diisocyanate (IPDI) is the diisocyanate and dioctyl adipate (DOA) is the plasticizer. Two different crystal high explosives components were used, hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), which is characterized

Mounir Jaidann; Hakima Abou-Rachid; Xavier Lafleur-Lambert; Jose Brisson

2011-01-01

40

Dynamic mechanical signatures of aged LX17-1 plastic bonded explosive  

Microsoft Academic Search

The complex shear modulus of the plastic bonded explosive (PBX) LX-17-1 from stockpile returns, core tests and historical billets was measured over the temperature range from ?150 to 120C at five frequencies from 0.1 to 10 Hz. LX-17-1 is composed of 92.5% insensitive high explosive triaminotrinitro-benzene (TATB) and 7.5% plastic binder, KF-800. Three relaxations were observed as peaks in the

D. Mark Hoffman

2001-01-01

41

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

SciTech Connect

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

NONE

1995-10-01

42

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

SciTech Connect

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

NONE

1996-12-01

43

A method for following unmarked roads  

Microsoft Academic Search

Road-following for ground vehicles has been widely studied and the solutions normally tracks line markings or a salient road edge. Most of the presented approaches are thus based on geometric or spectral models and does a fit of image data to the model to ensure robustness. For operation on unmarked roads under highly varying weather and light conditions a strategy

Ola Ramstrom; Henrik Christensen

2005-01-01

44

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

Microsoft Academic Search

Various plastic bonded explosives (PBXs) contain about 5wt.% polymer, plasticizer, and stabilizer as binder. The glass-transition temperature (Tg) 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

Mary Stinecipher Campbell; Danielle Garcia; Deanne Idar

2000-01-01

45

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

NASA Astrophysics Data System (ADS)

A ``damage-initiated reaction'' (DMGIR) computational model is presented for prediction of explosive response to non-shock mechanical insults. The distinguishing feature of this model is the introduction of a damage variable, which relates the evolution of damage to the initiation of reaction in the explosive, and the growth to detonation. The DMGIR model was embedded into an existing shock-physics computational code to utilize those existing, predictive capabilities as the basis for these non-shock predictions. The numerical approach is presented, with comparisons of DMGIR predictions to recent experiments utilizing non-shock initiation of the plastic bonded explosive PBXN-5. This model has been developed, and is presently being validated for plastic bonded explosives. Extension of the DMGIR model is planned for cast- and moldable-type explosives.

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

2007-12-01

46

Thermal properties and shelf life of HMXHTPB based plastic-bonded explosives  

Microsoft Academic Search

Plastic-bonded explosives (PBXs) with different amounts of polymer and based on explosives with different particle size distributions have been compared for their thermal properties and shelf life. Chung Shan Institute of Science and Technology has extensive experience with the processing of hydroxyl terminated polybutadiene (HTPB)-based PBXs. The investigation showed that the shelf life of HMX-based formulations is longer than 60

Jinn-Shing Lee; Chung-King Hsu

2002-01-01

47

Development of a high-tensile-strain plastic-bonded TATB explosive  

SciTech Connect

Typical plastic-bonded explosives (PBX) with greater than 90 weight-percent explosive filler in a fluorocarbon binder have tensile strains which range from 0.2 to 0.6{percent}. We have recently developed a TATB-based PBX with a tensile strain approaching 1{percent} while maintaining a high-volume loading of the crystalline explosive component. We discuss our formulation efforts to design a TATB/poly(styrene-(ethylene-butylene)-styrene)(Kraton){sup 1} PBX and the critical processing parameters which affect the ultimate mechanical properties of this PBX. 9 refs., 3 figs., 5 tabs.

Pruneda, C.; McGuire, R.; Clements, R.

1990-04-05

48

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

Microsoft Academic Search

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

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

1998-01-01

49

Thermal Decomposition of Plastic Bonded Explosives by Molecular Dynamic Simulations with the ReaxFF Force Field  

Microsoft Academic Search

Plastic bonded explosives (PBX) are a type of composite energetic materials in which a high explosive is dispersed in a polymer matrix. The main purpose of making such high explosive polymer bound is to reduce their sensitivity to shock, friction, impact, etc. Thermal decomposition is an essential process to characterize an energetic material, because it is one of main causes

Luzheng Zhang

2005-01-01

50

HIGH PERFORMANCE MELT-CAST PLASTIC-BONDED EXPLOSIVES  

Microsoft Academic Search

DRDC Valcartier has been developing new melt-cast explosives containing nitramines, TNT and a family of energetic thermoplastic elastomers (ETPEs) based on Glycidyl Azide Polymer. It was proven that the ETPEs, added in small amounts to the TNT, modified the glassy behaviour of the compositions and created a new product that showed enough elasticity to pass mechanical Insensitive Munitions tests such

P. Brousseau; G. Ampleman; S. Thiboutot; E Diaz; S. Trudel

51

Towards Accurate Molecular Modeling of Plastic Bonded Explosives  

Microsoft Academic Search

There is substantial interest in identifying the controlling factors that influence the susceptibility of polymer bonded explosives (PBXs) to accidental initiation. Numerous Molecular Dynamics (MD) simulations of PBXs using the COMPASS force field have been reported in recent years, where the validity of the force field in modeling the solid EM fill has been judged solely on its ability to

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

2010-01-01

52

Vapor phase detection of plastic explosives using a SAW resonator immunosensor array  

Microsoft Academic Search

We present the results of a series of experiments demonstrating on-the-spot detection of low vapor pressure plastic explosives containing nitro groups such as RDX, TNT, and their analogous substances, facilitated by the Transportation Security Administration (TSA) Lab. A set of antibody coated SAW resonators inside the flow cell detect the presence of the target molecules diffusing from the sample. Monoclonal

Sang-Hun Lee; D. D. Stubbs; W. D. Hunt; P. J. Edmonson

2005-01-01

53

The Strength of Plastic Bonded Explosives as a Function of Pressure, Strain Rate and Temperature  

Microsoft Academic Search

Measurements as a function of strain rate and temperature have indicated the importance of the polymer binder in determining the strength of plastic bonded explosives at ambient conditions and low strain rate. Recent measurements of strength as a function of pressure further support this conclusion. As pressure or strain rate are increased or temperature is decreased the strength increases as

Donald Wiegand

2005-01-01

54

The Strength of Plastic Bonded Explosives as a Function of Pressure, Strain Rate and Temperature  

NASA Astrophysics Data System (ADS)

Measurements as a function of strain rate and temperature have indicated the importance of the polymer binder in determining the strength of plastic bonded explosives at ambient conditions and low strain rate. Recent measurements of strength as a function of pressure further support this conclusion. As pressure or strain rate are increased or temperature is decreased the strength increases as does the strength of many polymers. In addition, at relatively large values of pressure or strain rate and/or relatively low values of temperature the strength is less sensitive to changes of these quantities. These trends suggest that as the polymer binder becomes stronger with increasing pressure or strain rate or with decreasing temperature, the strength of the explosive component of these composites becomes more important in determining the strength of the composite. Results will be presented for plastic bonded explosives, e.g., LX-14, that demonstrate these trends as a function of pressure, strain rate and temperature.

Wiegand, Donald

2005-07-01

55

Non-Shock Initiation of the Plastic Bonded Explosive PBXN-5: Experimental Results  

NASA Astrophysics Data System (ADS)

The plastic bonded explosive PBXN-5 was studied under impulsive loading experiments to relate impact-induced mechanical damage to the onset of, and the extent of reaction produced. A small diameter projectile generated shock and release conditions at the impact interface, on the microsecond time scale during the initial portion of the impulsive loading. These shock and release wave interactions generate significant damage, resulting in a porous, powder compaction-type initiation behavior. Experimental measurements show an energy threshold for initiation of reaction which relates to impact-induced kinetic energy. These results are implemented in the model development and validation phases of the damage-induced reaction (DMGIR) model, which is used to simulate impact scenarios of explosives, explosive components, and explosive systems.

Lappo, K. N.; Todd, S. N.; Anderson, M. U.; Vogler, T. J.

2007-12-01

56

Towards Accurate Molecular Modeling of Plastic Bonded Explosives  

NASA Astrophysics Data System (ADS)

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

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

2010-03-01

57

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

SciTech Connect

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

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

1997-10-01

58

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

SciTech Connect

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

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

1996-07-01

59

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

60

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

61

Marked and Unmarked Choices of Code Switching in Bilingual Poetry.  

ERIC Educational Resources Information Center

|Presents a model of the speaker's sociopsychological motivations when he engages in code-switching (CS). The use of CS can be interpreted as a marked or an unmarked choice of discourse mode. (38 references) (Author/CK)|

Mendieta-Lombardo, Eva; Cintron, Zaida A.

1995-01-01

62

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

SciTech Connect

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 new analysis of the wedge test was implemented. Based on wedge test results, an approximation for the particle velocity at the shock front is constructed, which is used in functional composition with the Hugoniot to calculate the shock path of each experiment. Optimization on the parameters of the approximation and the Hugoniot simultaneously ensures agreement of the Hugoniot with the overall kinematics of the shock growth as well as the particle velocity/shock velocity data. The individual shock paths are used to examine the single-curve buildup assumption; the assumption is not valid for PBX 9502. A ramping elastic precursor of 0.073 GPa strength was observed. The yield and weak shock behavior are interpreted in terms of porosity, crystalline anisotropy, and residual strain in the pressed, plastic-bonded explosive.

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

1988-05-15

63

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

PubMed

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

Petterson, Ingeborg E Iping; Lpez-Lpez, Mara; Garca-Ruiz, Carmen; Gooijer, Cees; Buijs, Joost B; Ariese, Freek

2011-10-17

64

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

65

Effects of severe plastic deformation and heat treatment on transformation behavior of explosively welded duplex TiNi?TiNi  

Microsoft Academic Search

The effects of severe plastic deformation and heat treatment on the transformation behavior of explosively welded duplex TiNi-TiNi\\u000a shape memory alloys (SMAs) were investigated by differential scanning calorimeter (DSC) measurements. The explosively welded\\u000a duplex TiNi-TiNi plate of 0.7 mm thickness was cold-rolled at room temperature to a 60% reduction in thickness and then annealed\\u000a at different temperatures for different durations.

Li Juntao; Zheng Yanjun; Cui Lishan

2007-01-01

66

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

67

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

68

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

Microsoft Academic Search

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

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

1999-01-01

69

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

NASA Astrophysics Data System (ADS)

Numerical simulations of the heating with constant rate of a PBX (plastic-bonded explosive) 9501 formulation consisting of the energetic crystal HMX embedded in a polymeric binder inside of a rigid cylinder is performed. The continuum thermo-mechanochemical model of the behavior of a PBX 9501 developed in the preceding paper [V. I. Levitas, B. F. Henson, L. B. Smilowitz, D. K. Zerkle, and B. W. Asay, J. Appl. Phys. 102, 113502 (2007)] is applied. The model describes the ?<-->? phase transformations in crystalline HMX, 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. We study the kinetics of the ?<-->? phase transformations and pressure buildup, as well as how they are affected by the heating rate, initial porosity and prestrain, HMX and binder decomposition, and gas leaking rule.

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

2007-12-01

70

Pilot-scale pressurized base hydrolysis of HMX plastic-bonded explosives  

SciTech Connect

A pilot-scale, pressurized, base hydrolysis reactor has been designed and its construction is nearly completed. Up to 120 L of 1--6 M NaOH aqueous solutions will convert as much as 25 kg of consolidated, explosive pieces to non-energetic compounds. Temperatures approaching 155 C in the pressurized unit will reduce reaction times significantly for the destruction of plastic-bonded explosives compared to previous atmospheric-pressure reactors. The hydrolysis effluent is then pumped into a holding tank where it is fed into a hydrothermal oxidation reactor for complete destruction to non-hazardous products. The hydrothermal unit operates at 480 C and 100 MPa and hydrogen peroxide fed into the reactor at two points will ensure complete destruction of all organic species and nitrogen-containing salts. The entire system is comprised of eight major components and is assembled on five separate and transportable skids. Following construction and preliminary testing at Los Alamos National Laboratory, the unit will be shipped to the Pantex Plant where it will be used for continuous demilitarization activities.

Larson, S.A.; Brewer, G.R.; Harradine, D.M.; Polston, C.E.; Le, L.A.; Bishop, R.L.; Dell`Orco, P.C.; Flesner, R.L.

1998-12-31

71

Effects of binder concentration on the properties of plastic-bonded explosives  

SciTech Connect

A series of plastic-bonded explosives (PBX) has been formulated with more binder than is normally contained in high-energy formulations. Adding a relatively small amount of binder to a material such as PBX 9501 (95/2.5/1.25/1.25 wt % HMX/Estane/BDNPA/BDNPF (the BDNPA and BDNPF form a eutectic that is frequently called simply the eutectic)) was found to decrease the shock sensitivity while not decreasing the energy of the explosive. The best compromise for a PBX 9501-type material contains about 92 wt % HMX. Adding additional binder does not continue to decrease the gap sensitivity of the formulation; however, the energy of the PBX decreases as expected. The higher-binder formulations are of potential use because of the possibility of formulating a PBX with energy similar to TATB formulations, such as PBX 9502 (95/5 wt % TATB/Kel-F 800), and with a higher strain to failure. 2 refs., 4 figs., 1 tab.

Steele, R.D.; Stretz, L.A.; Taylor, G.W.; Rivera, T.

1989-01-01

72

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

73

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

74

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

75

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

76

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

PubMed

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

Bolme, C A; Ramos, K J

2013-08-01

77

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

PubMed

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 (F(2311)), and fluorine resin (F(2314)). 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 properties of RDX can be effectively improved by blending with a small amount of fluorine polymers and the overall effect of fluorine polymers on the mechanical properties of the PBXs along three crystalline surfaces is (001)>(010) approximately (100) and PVDF is regarded to best improve the mechanical properties of the PBXs on three surfaces. The order of the improvement in the ductibility made by the fluorine polymers on different surfaces is (001) approximately (010)>(100). The average binding energies between different RDX crystalline surfaces and different polymer binders are obtained, and the sequence of the binding energies of the PBXs with the four fluorine polymers on the three different surfaces is varied. Among the polymer binders, PVDF is considered as best one for RDX-based PBXs. The detonation performances of the PBXs decrease in comparison with the pure crystal but are superior to those of TNT. PMID:18938030

Zhu, Wei; Xiao, Jijun; Zhu, Weihua; Xiao, Heming

2008-09-13

78

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

Microsoft Academic Search

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

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

1994-01-01

79

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

PubMed

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

Zhuang, Xiangling; Wu, Changxu

2011-06-02

80

Thermal Decomposition of Plastic Bonded Explosives by Molecular Dynamic Simulations with the ReaxFF Force Field  

NASA Astrophysics Data System (ADS)

Plastic bonded explosives (PBX) are a type of composite energetic materials in which a high explosive is dispersed in a polymer matrix. The main purpose of making such high explosive polymer bound is to reduce their sensitivity to shock, friction, impact, etc. Thermal decomposition is an essential process to characterize an energetic material, because it is one of main causes of initiation of the explosives. In this work, we used MD simulations with the reactive force field (ReaxFF) to study the thermal decomposition of RDX crystal boned with polyurethane chains (Estane) and with nitrocellulose chains. The simulation results showed that RDX's thermal decomposition processing varies when a polymer binder was bonded to the crystal. With addition of polymer binders, RDX's sensitivity is reduced. In all cases studied, the products such as N2, H2O, CO, CO2, OH, etc. can be identified. However, the contributions to these individual species are different: nitrocellulose has much more contributions to N2, CO2, and CO; but Estane has a little contributions to H2O and almost no contributions to N2, CO and CO2. In addition, we found that the decomposition of RDX with Estane along the Y-direction is slower than that along the X-direction.

Zhang, Luzheng

2005-03-01

81

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

82

Cost-effective synthesis of 5,7-diamino-4,6-dinitrobenzofuroxan (CL-14) and its evaluation in plastic bonded explosives.  

PubMed

5,7-Diamino-4,6-dinitrobenzofuroxan (CL-14) has been synthesized by a cost-effective method. CL-14 was characterized by spectral data (IR, NMR and mass) and elemental analysis. The compound was evaluated in plastic bonded explosives (PBX) using polyurethane (PU) as binder. The thermal, mechanical and explosive properties of PBX composition from preliminary tests are also reported. Good thermal stability as well as good insensitiveness are indicated. PMID:12972233

Mehilal; Sikder, A K; Sinha, R K; Gandhe, B R

2003-08-29

83

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

84

Frequency and intentionality in (un)marked choices in codeswitching: This is a 24-hour country  

Microsoft Academic Search

This paper has three, related goals. Its main goal is to provide quantitative evidence supporting the claim that in bilingual conversation the unmarked choice can be identified via a frequency-based criterion(cf. Myers-Scotton,1993b). Accordingly, frequency also identifies the marked choice. Second, it shows that not all participants in the same conversation necessarily have the same unmarked choice. Data come from a

Carol Myers-Scotton

2002-01-01

85

Dynamic mechanical and molecular weight measurements on polymer bonded explosives from thermally accelerated aging tests. III. Kraton block copolymer binder and plasticizers  

SciTech Connect

The dynamic mechanical properties and molecular weight distribution of two experimental polymer bonded explosives, X-0287 and X-0298, maintained at 23, 60, and 74/sup 0/C for 3 years were examined. X-0287 is 97% 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane explosive, 1.8% Kraton G-1650, and 1.2% B/sup 2/ was 170. X-0298 is 97.4% explosive, 1.4% Kraton G-1650, and 1.2% Cenco Hi-vac oil. The relaxation associated with the Kraton rubber block glass transition is observed in both X-0287 and X-0298. In the unaged X-0298 it occurs at -59/sup 0/C and in the aged explosive at 50/sup 0/C. This is caused by migration of the oil plasticizer out of the explosive. In X-0287 the Kraton rubber block T/sub g/ is weak and broad due to the presence of the wax plasticizer. X-0287 has a second broad relaxation associated with the melting of the wax from 10 to 65/sup 0/C. The molecular weight of the Kraton binder decreased with increasing accelerated aging temperature. The oil plasticizer had no stabilizing effect, but below its melting point the wax reduced Kraton chain scission considerably. The simple random chain scission model predicted a 20.5 year use-life for X-0298, but X-0287 was stabilized against degradation below the wax melting point.

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

1981-01-01

86

Meso-scale origins of the low-pressure equation of state and high rate mechanical properties of plastic bonded explosives  

Microsoft Academic Search

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. 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

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

2000-01-01

87

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

Microsoft Academic Search

The coefficient of friction, ?, of PBX 9404 was measured on stainless steel, aluminum, polytetrafluoroethylene (PTFE), and the explosive itself between ambient and 135C at a rotational speed of 0.0025rad\\/s. The mean surface roughness, Ra, of the various materials was analyzed by an optical profilometer. For PBX 9404 on stainless steel, ? increased from 0.22 at 25?C to 0.34 at

D. MARK HOFFMAN; JEFFREY B. CHANDLER

2004-01-01

88

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

SciTech Connect

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

Reaugh, J E

2009-05-07

89

Explosive simulants for testing explosive detection systems  

DOEpatents

Explosives simulants that include non-explosive components are disclosed that facilitate testing of equipment designed to remotely detect explosives. The simulants are non-explosive, non-hazardous materials that can be safely handled without any significant precautions. The simulants imitate real explosives in terms of mass density, effective atomic number, x-ray transmission properties, and physical form, including moldable plastics and emulsions/gels.

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

1999-09-28

90

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

NASA Astrophysics Data System (ADS)

In large explosive and propellant charges, relatively low shock pressures on the order of 1-2 GPa impacting large volumes and lasting tens of microseconds can cause shock initiation of detonation. The pressure buildup process requires several centimeters of shock propagation before shock to detonation transition occurs. In this paper, experimentally measured run distances to detonation for lower input shock pressures are shown to be much longer than predicted by extrapolation of high shock pressure data. Run distance to detonation and embedded manganin gauge pressure histories are measured using large diameter charges of six octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) based plastic bonded explosives (PBX's): PBX 9404; LX-04; LX-07; LX-10; PBX 9501; and EDC37. The embedded gauge records show that the lower shock pressures create fewer and less energetic ``hot spot'' reaction sites, which consume the surrounding explosive particles at reduced reaction rates and cause longer distances to detonation. The experimental data is analyzed using the ignition and growth reactive flow model of shock initiation in solid explosives. Using minimum values of the degrees of compression required to ignite hot spot reactions, the previously determined high shock pressure ignition and growth model parameters for the six explosives accurately simulate the much longer run distances to detonation and much slower growths of pressure behind the shock fronts measured during the shock initiation of HMX PBX's at several low shock pressures.

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

2010-05-01

91

A Color Vision-Based Lane Tracking System for Autonomous Driving on Unmarked Roads  

Microsoft Academic Search

This work describes a color Vision-based System intended to perform stable autonomous driving on unmarked roads. Accordingly, this implies the development of an accurate road surface detection system that ensures vehicle stability. Although this topic has already been documented in the technical literature by different research groups, the vast majority of the already existing Intelligent Transportation Systems are devoted to

Miguel ngel Sotelo; Francisco Javier Rodrguez; Luis Magdalena; Luis Miguel Bergasa; Luciano Boquete

2004-01-01

92

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

93

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

Code of Federal Regulations, 2013 CFR

...Review of unmarked documents with potential restricted data or formerly restricted data. 1045.45 Section 1045.45 Energy DEPARTMENT...Generation and Review of Documents Containing Restricted Data and Formerly Restricted Data § 1045.45...

2013-01-01

94

Application of an inducible system to engineer unmarked conditional mutants of essential genes of Pseudomonas aeruginosa.  

PubMed

The Phi CTX-based integration vector pYM101 harboring a tightly controlled modified phage T7 early gene promoter/LacI(q) repressor (T7/LacI) system was constructed for the generation of unmarked conditional mutants in Pseudomonas aeruginosa. Promoter activity of the T7/LacI system was demonstrated to be dependent on the presence of the inducer isopropyl -beta-D-1-thiogalactopyranoside (IPTG), as evaluated by measuring beta-galactosidase activity. In the absence of the inducer, the promoter was silent as its activity was lower than those of a promoter-less lacZ control. Unmarked conditional mutants of four predicted essential genes (lolCDE (PA2988-86), lpxC (PA4406), rho (PA5239), and def (PA0019)) were successfully constructed using this recombination system. In the absence of IPTG, the growth of all mutants was repressed; however, the addition of either 0.1 or 1mM IPTG restored growth rates to levels nearly identical to wild-type cells. It was therefore demonstrated that the inducible integration vector pYM101 is suitable for the creation of unmarked conditional mutants of P. aeruginosa, and is particularly useful for examining the function of essential genes. PMID:20538017

Morita, Yuji; Narita, Shin-ichiro; Tomida, Junko; Tokuda, Hajime; Kawamura, Yoshiaki

2010-06-09

95

Plasticity  

Microsoft Academic Search

SummaryOver the past 20 years, evidence has mounted regarding the capacity of the central nervous system to alter its structure and\\u000a function throughout life. Injury to the central nervous system appears to be a particularly potent trigger for plastic mechanisms\\u000a to be elicited. Following focal injury, widespread neurophysiological and neuroanatomical changes occur both in the peri-infarct\\u000a region, as well as

Randolph J. Nudo; Brian R. Christie; Andreas Frick; Richard Gray; Dax A. Hoffman; Lalania K. Schexnayder; Shigeo Watanabe; Li-Lian Yuan

2006-01-01

96

Method for preparation of fine TATB (2-5 microm) and its evaluation in plastic bonded explosive (PBX) formulations.  

PubMed

There is a need of fine 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) (2-5 microm) for various high explosive formulations to achieve desired mechanical strength, ease in processing and finally, provide better performance of end product. The reprecipitation method for TATB has been developed using concentrated sulfuric acid as a solvent. The reprecipitation parameters of TATB were optimized to achieve required fine TATB of particle size approximately 2-5 microm. The characteristic properties of fine TATB thus obtained have been confirmed by FTIR, DSC and TG-FTIR. The spectroscopic and thermal data obtained for fine TATB were compared with standard coarse TATB and found chemically unchanged during particle size reduction. In the present study, the preparation of fine TATB was also attempted using ultrasonication method. The fine (2-5 microm) TATB has been introduced to study in the bimodal high explosive formulations. High explosive formulations based on coarse (55 microm) and fine TATB ( approximately 2-5 microm) with 10% polyurethane were studied. It was observed that properties like bulk density (1.70 g/cm(3)), mechanical strength/compressed strength (115.9 mg/cm(2)), %elongation (6.36) were improved for fine TATB in comparison with coarse TATB ( approximately 55 microm) alone in high explosive formulations. PMID:16844291

Talawar, M B; Agarwal, A P; Anniyappan, M; Gore, G M; Asthana, S N; Venugopalan, S

2006-05-16

97

Molecular simulation of the influence of interface faceting on the shock sensitivity of a model plastic bonded explosive.  

PubMed

Molecular dynamics simulations are used to model the shock loading of an interface with various degrees of nanometer scale faceting between an inert binder and an energetic crystal. The facets create regions of local compression that induce exothermic reaction that leads to local hotspots and an increased shock sensitivity to detonation. Two mechanisms for compression and hotspot formation are identified that depend on the shock impedance mismatch between the binder and energetic crystal, namely shock focusing and local compression of the facets. These results provide a possible explanation for why spherical RDX crystals in cast polymer-bonded explosives appear less shock sensitive than RDX with more faceted morphologies. PMID:18973371

Shi, Yunfeng; Brenner, Donald W

2008-11-27

98

The role of the posterior superior temporal sulcus in the processing of unmarked transitivity.  

PubMed

Is it living or not? The ability to differentiate between animate and inanimate entities is of considerable value in everyday life, since it allows for the dissociation of individuals that may willfully cause an action from objects that cannot. The present fMRI study aimed to shed light on the neural correlates of animacy at a relational-interpretive level, i.e. on the role of animacy in the establishment of relations between entities that are more or less likely to cause an event and differ in their potential to act volitionally. To this end, we investigated the processing of visually presented transitive German sentences (nominative-accusative structures) in which the factors animacy and argument order were manipulated. The relations between the arguments differed in that the animate subject either acted on an inanimate object (a very natural construction in terms of transitivity) or on an animate object (resulting in a sentence deviating from an unmarked transitive structure). Participants performed an acceptability judgment task. Violations of unmarked transitivity yielded a significant activation increase within the posterior left superior temporal sulcus (pSTS), thus suggesting a specific role of this cortical region in the relational use of animacy information. This result indicates that the influence of animacy as a relational feature differs from the impact of this parameter on the word level and is in line with other neuroimaging studies showing an engagement of the pSTS when a matching between syntax and semantics is required. A comparison between object- and subject-initial conditions further revealed a robust effect of argument order in the pars opercularis of the left inferior frontal gyrus (a subregion of Broca's area), thereby replicating previous findings demonstrating a sensitivity of this region to fine-grained language-specific linearization rules. PMID:17222565

Grewe, Tanja; Bornkessel-Schlesewsky, Ina; Zysset, Stefan; Wiese, Richard; von Cramon, D Yves; Schlesewsky, Matthias

2007-01-11

99

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

100

Explosives detection with quadrupole resonance analysis  

Microsoft Academic Search

The increase in international terrorist activity over the past decade has necessitated the exploration of new technologies for the detection of plastic explosives. Quadrupole resonance analysis (QRA) has proven effective as a technique for detecting the presence of plastic, sheet, and military explosive compounds in small quantities, and can also be used to identify narcotics such as heroin and cocaine

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

1997-01-01

101

Failure analysis for cylindrical explosion containment vessels  

Microsoft Academic Search

The elastic or elasticplastic dynamical response of the explosion containment vessels (ECVs) subject to the impulsive loading have been studied intensively, however the damage mechanism of ECVs is still scarcely investigated. In this work two cylindrical explosion containment vessels under the different explosion loads are tested. The overpressure is measured and compared with the numerical result. The damage mechanism of

Li Ma; Yang Hu; Jinyang Zheng; Guide Deng; Yongjun Chen

2010-01-01

102

Dynamic mechanical and molecular weight measurements on polymer bonded explosives from thermally accelerated aging tests. III. Kraton block copolymer binder and plasticizers  

Microsoft Academic Search

The dynamic mechanical properties and molecular weight distribution of two experimental polymer bonded explosives, X-0287 and X-0298, maintained at 23, 60, and 74°C for 3 years were examined. X-0287 is 97% 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane explosive, 1.8% Kraton G-1650, and 1.2% B² was 170. X-0298 is 97.4% explosive, 1.4% Kraton G-1650, and 1.2% Cenco Hi-vac oil. The relaxation associated with the Kraton rubber

L. E. Caley; D. M. Hoffman

1981-01-01

103

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

104

LLNL explosives handbook: properties of chemical explosives and explosives and explosive simulants  

SciTech Connect

This handbook presents information and data for high explosives (HEs) of interest to programs at the Lawrence Livermore National Laboratory (LLNL) and other Department of Energy (DOE) facilities. It is intended to be useful to the scientist or engineer, the novice or expert, who needs to develop a new weapon system, design a physics experiment, or select and/or evaluate an existing explosive. This compilation is limited to production HEs and their components. High explosives are divided into two classes: initial detonating (or primary) and noninitiating (or secondary) explosives. The primary HEs, such as azides and fulminates, are extremely sensitive to ignition by heat, shock, and electrical discharge; ignition leads to high-order detonation of the material - even for milligram quantities. The use of these HEs is therefore limited to squibs and starting materials for low-energy detonators. Because primary explosives have little application at LLNL, this compilation includes only the properties of lead azide and lead styphnate. Secondary HEs as a class comprise single compounds of mixtures; the mixtures contain one or more explosive compounds and one or more of the following ingredients: metals, binders, plasticizers, sensitizers or desensitizers, oxidizers, and a coloring agent. Because many of the secondary high explosives are mixtures, the properties of the additives and binders used are included. The data are the most up-to-date and accurate available to the knowledge of the compiler. The sources of information include textbooks, journal articles, technical reports, memoranda, letters, and personal communications. The reader is urged to consult the source document to properly evaluate and interpret the data given in this compilation. The compilation consists of sections on high explosives and mock explosives, formulation nomenclature (codes), data sheets on individual materials, and a bibliography.

Dobratz, B.M.

1981-03-16

105

Dynamic Mechanical and Molecular Weight Measurements on Polymer Bonded Explosives from Thermally Accelerated Aging Tests. III. Kraton Block Copolymer Binder and Plasticizers.  

National Technical Information Service (NTIS)

The dynamic mechanical properties and molecular weight distribution of two experimental polymer bonded explosives, X-0287 and X-0298, maintained at 23, 60, and 74 exp 0 C for 3 years were examined. X-0287 is 97% 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooct...

L. E. Caley D. M. Hoffman

1981-01-01

106

Use of a flexible cassette method to generate a double unmarked Mycobacterium tuberculosis tlyA plcABC mutant by gene replacement  

Microsoft Academic Search

Progress in the field of mycobacterial research has been hindered by the inability to readily generate defined mutant strains of the slow-growing mycobacteria to investigate the function of specific genes. An efficient method is described that has been used to generate several mutants, including the first double unmarked deletion strain of Mycobacterium tuberculosis. Four mutants were constructed: a marked deletion

Tanya Parish; Neil G. Stoker

2000-01-01

107

Mechanical Behavior of Explosives at High Pressures  

Microsoft Academic Search

The mechanical and ignition behaviors of heterogeneous explosives and pure polymeric binders used in plastic-bonded explosive are highly dependent on the pressure. New apparatus capable of testing small explosive samples under pressures reaching 10 kbar were developed. Unlike previous designs that use a cylinder-piston arrangement, here the samples are quasi-statically and dynamically compacted in a working fluid, thus ensuring isotropic

John Kelley; Vasant Joshi; Raafat Guirguis

2001-01-01

108

Appearances of internal micro bubbling, multiple micro explosions, multiple micro jets and micro diffusion flames around an abruptly heated micro plastic-resin particle  

Microsoft Academic Search

Heating, gasifying and burning processes of a micro plastic-resin particle, which has a diameter of about 200?m and is suddenly exposed to a hot oxidizing atmosphere, are observed and optically processed by combining a micro schlieren system with a high-speed CCD video camera. The following three devised approaches are introduced: the use of an oxidizing combustion gas downstream of a

Yojiro Ishino; Ryuji Yamakita; Norio Ohiwa

2007-01-01

109

Spatial and trophic overlap of marked and unmarked Columbia River Basin spring Chinook salmon during early marine residence with implications for competition between hatchery and naturally produced fish  

Microsoft Academic Search

Ecological interactions between natural and hatchery juvenile salmon during their early marine residence, a time of high mortality,\\u000a have received little attention. These interactions may negatively influence survival and hamper the ability of natural populations\\u000a to recover. We examined the spatial distributions and size differences of both marked (hatchery) and unmarked (a high proportion\\u000a of which are natural) juvenile Chinook

Elizabeth A. Daly; Richard D. Brodeur; Joseph P. Fisher; Laurie A. Weitkamp; David J. Teel; Brian R. Beckman

110

(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

111

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

112

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

113

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

114

Explosives sensor  

SciTech Connect

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

Not Available

1987-01-01

115

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

116

Explosive complexes  

SciTech Connect

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

117

Plastics from the User's Point of View.  

National Technical Information Service (NTIS)

Various plastic packs and accessories used for chemicals, explosives and agricultural products are reviewed. The type of pack being used and the procedures which have been developed for filling, handling and distributing products so packed are discussed.

R. D. Gillespie

1977-01-01

118

Wax or Plastic Coated Phosphor Grains.  

National Technical Information Service (NTIS)

Phosphor grains coated with wax or plastic coating compositions comprising hydrocarbons are useful as tagging phosphors for explosives. The coating composition can incorporate UV opacifiers, coloring agents or antistatic agents, or mixtures of them.

H. R. Heytmeijer E. S. Panaccione

1976-01-01

119

49 CFR 173.60 - General packaging requirements for explosives.  

Code of Federal Regulations, 2010 CFR

...from making contact with metal packagings. Articles containing explosive...partitioning in the inner or outer packaging, molded plastics or receptacles may be used for this purpose. (4) When the packaging includes water that...

2010-10-01

120

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

121

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

122

Remote concealed weapons and explosive detection on people using millimeter-wave holography  

Microsoft Academic Search

The need for a concealed weapons and explosive detection systems in uncontrolled environments has increased in recent years. Traditional metal detector inspection systems are limited to controlled environments such as security check points and cannot detect plastic explosives. Civilian and military security personnel need technologies capable of detection of concealed weapons and explosives at remote distances for enhanced safety reasons.

D. L. McMakin; D. M. Sheen; H. D. Collins

1996-01-01

123

Method for digesting a nitro-bearing explosive compound  

DOEpatents

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

Shah, Manish M. (Richland, WA)

2000-01-01

124

Explosive Wave Shaper.  

National Technical Information Service (NTIS)

An explosive wave shaping system or wave shaper is disclosed. A 'flying' plate or disk of uniform thickness between the donor explosive and the acceptor explosive. The plate is driven against the acceptor explosive with sufficient force to detonate it. Th...

T. P. Liddiard

1965-01-01

125

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

126

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

127

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

128

Non-Shock Initiation Model for Explosive Families: Numerical Results  

NASA Astrophysics Data System (ADS)

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

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

2009-12-01

129

Explosives detection with energetic photons  

NASA Astrophysics Data System (ADS)

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

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

1991-05-01

130

Totally Confined Explosive Welding.  

National Technical Information Service (NTIS)

A method is described for eliminating the noise and debris of explosive welding techniques by totally enclosing and applying the explosive pressure through the wall of an enclosure. This method eliminates the problem of scattering debris, and personnel ha...

L. J. Bement

1973-01-01

131

Intermittent Explosive Disorder  

MedlinePLUS

... be reprinted for personal, noncommercial use only. Intermittent explosive disorder By Mayo Clinic staff Original Article: http://www.mayoclinic.com/health/intermittent-explosive-disorder/DS00730 Definition Symptoms Causes Risk factors Complications ...

132

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

133

Dinitropropyl Fluorodinitroethyl Formal Plasticizer and Method of Preparation.  

National Technical Information Service (NTIS)

This invention relates to organic formals and more particularly to polynitro organic formals. Bis(2-fluoro-2,2-dinitroethyl) formal (FEFO) and Bis(2,2-dinitropropyl) formal (BDNPF) are used as energetic plasticizers in explosive and propellant composition...

H. G. Adolph

1982-01-01

134

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

135

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

136

Plastic Buckling.  

National Technical Information Service (NTIS)

A survey of plastic buckling is given. Emphasis is placed on post-buckling behavior and imperfection-sensitivity in the plastic range, although the extent to which bifurcation load predictions depend on the choice of plasticity theory is reviewed at some ...

J. W. Hutchinson

1973-01-01

137

Bioremediation of high explosives  

Microsoft Academic Search

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

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

1995-01-01

138

Totally Confined Explosive Welding.  

National Technical Information Service (NTIS)

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 s...

L. J. Bement

1974-01-01

139

75 FR 5545 - Explosives  

Federal Register 2010, 2011, 2012, 2013

...and OSHA-S-031)] RIN 1218-AC09 Explosives AGENCY: Occupational Safety and Health...terminating the rulemaking to amend its Explosives and Blasting Agents Standard at 29 CFR...of the Act, OSHA promulgated its Explosives and Blasting Agents Standard at 29...

2010-02-03

140

Mechanical Behavior of TNAZ/Hytemp Explosives during High Acceleration  

NASA Astrophysics Data System (ADS)

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

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

2006-07-01

141

Preparation of polymer nanocomposites by explosive processing  

Microsoft Academic Search

This work is aimed at preparing polymer nanocomposites or, in the case of high-filled composites with a metal content of over\\u000a 50%, organometallic nanoalloys by explosive processing of powder polymer-metal mixes with a metal dispersion of no more than\\u000a 100m. The nanostructuring is a result of the jet-like flow, intense localized plastic deformation, the crushing of initial\\u000a structural components followed

N. A. Adamenko; A. V. Kazurov; A. V. Fetisov; G. V. Agafonova

2009-01-01

142

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

143

A simple model for explosives formulation  

SciTech Connect

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

Rivera, T.

1993-04-01

144

A simple model for explosives formulation  

SciTech Connect

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

Rivera, T.

1993-01-01

145

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

146

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

147

Predicting the effect of explosive porosity on sensitivity using CREST  

NASA Astrophysics Data System (ADS)

CREST is a reactive-burn model that uses entropy-dependent reaction rates to model shock initiation and detonation behaviour in plastic bonded explosives. A CREST model for the TATB-based high explosive PBX9502 was published previously at this conference. It is well known that changing the porosity of an explosive, like PBX9502, can dramatically influence its sensitivity. The equation of state used in CREST incorporates the snow-plough model, allowing the porosity of the explosive to be selected at will, while keeping the reaction model constant. In this paper, it will be shown that CREST can predict the change in explosive sensitivity with porosity, as demonstrated by the experimentally determined Pop-plots for TATB. In contrast, it will be shown that pressure-dependent reactive-burn models are unable to predict this porosity effect.

Handley, Caroline

2009-06-01

148

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

149

Method of digesting an explosive nitro compound  

DOEpatents

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

Shah, Manish M. (Richland, WA)

2000-01-01

150

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

151

Model of plastic deformation for extreme loading conditions  

Microsoft Academic Search

We present a model of metallic plastic flow suitable for numerical simulations of explosive loading and high velocity impacts. The dependence of the plastic strain rate on applied stress at low strain rates is of the Arrhenius form but with an activation energy that is singular at zero stress so that the deformation rate vanishes in that limit. Work hardening

Dean L. Preston; Davis L. Tonks; Duane C. Wallace

2003-01-01

152

Phytoremediation of Toxic Explosives  

Microsoft Academic Search

\\u000a Widespread contamination of the environment by explosives resulting from the manufacture, disposal and testing of munitions\\u000a is becoming a matter of increasing concern. Most explosives are considered to be a major hazard to biological systems due\\u000a to their toxic and mutagenic effects. Interest on the bioremediation of lands contaminated with explosives has recently been\\u000a focused on phytoremediation. Unfortunately, whilst plants

Nand Lal; Neerja Srivastava

153

Explosives tester with heater  

DOEpatents

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

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

2010-08-10

154

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

155

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

Microsoft Academic Search

This document describes an evaluation of the Level II Milestone achievements of the LLNL program on Grain-Scale Dynamics in Explosives on January 14, 2003. ''The Grain-Scale Dynamics in Explosives Program'' is a mixture of advanced computational methodology and physico-chemical theory applied to understanding deflagration and detonation of plastic-bonded explosives from the nano to the macro scales. At many points, the

M F Nicol; D J Benson; S Yip

2003-01-01

156

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

Microsoft Academic Search

Landmine detection is an important task for military operations and for humanitarian demining. Conventional methods for landmine detection involve measurements of physical properties. Several of these methods fail on the detection of modern mines with plastic enclosures. Methods based on the detection signature explosives chemicals such as TNT and DNT are specific to landmines and explosive devices. However, such methods

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

2004-01-01

157

Effects of radiation on DMSO solutions with polymeric binders and HMX high explosive  

SciTech Connect

A newly developed dismantlement process uses dimethyl sulfoxide (DMSO) solvent to remove plastic bonded HMX explosives (PBX-9404 and LX-10) from bonded nuclear assemblies. It is remotely possible in this process that DMSO solutions of the explosives will come into prolonged contact with plutonium. This paper addresses the anticipated chemistry and consequences of this contact.

Colmenares, C.A.; LeMay, J.D.

1994-08-01

158

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

159

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.

160

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

Federal Register 2010, 2011, 2012, 2013

...SUPPLEMENTARY INFORMATION: The list includes all mixtures containing any of the materials on the...after ``Black powder based explosive mixtures'' on the List of Explosive Materials...Explosive Materials under their chemical, mixture or common names, ATF believes that...

2013-10-28

161

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

162

Explosive Auto-Enhancement Device.  

National Technical Information Service (NTIS)

An explosive auto-enhancement device for providing higher detonation pressure than can be achieved with conventional explosives by the use of magnetic precompression for enhancing the detonation wave. A cylindrical armature containing an explosive charge ...

E. T. Toten E. Zimet

1980-01-01

163

Explosively pumped laser light  

DOEpatents

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

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

1991-01-01

164

Entropy in supernova explosions.  

National Technical Information Service (NTIS)

The explosion of a supernova forms because of the collapse to a neutron star. In addition an explosion requires that a region of relatively high entropy be in contact with the neutron star and persisting for a relatively protracted period of time. The hig...

S. A. Colgate

1990-01-01

165

Inside an Explosion  

NSDL National Science Digital Library

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

Kqed

2009-10-30

166

Bioremediation of explosives  

Microsoft Academic Search

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

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

1990-01-01

167

Underwater explosive welding of thin tungsten foils and copper  

Microsoft Academic Search

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

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

2011-01-01

168

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

169

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

170

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

171

Reaction of preshocked explosives  

SciTech Connect

In experiments in which an explosive is subjected to two successive shocks ({approximately}2.5 and {approximately}6.0 GPa), detonation of the explosive is delayed. High compaction resulting from shock compression of an explosive probably results in the removal of voids from the material. To the extent that these voids comprise the hotspots in the material, the shock-compressed explosive might be expected to behave as a homogeneous material, and initiate more like a liquid explosive than like a normal solid PBX. While some evidence is available from the data record to support this idea that detonation develops in a homogeneous manner, predominant aspects of the data indicate heterogeneous development of detonation in the preshocked material.

Mulford, R.N.

1998-07-31

172

Non-Solid Explosives for Shaped Charges. Part II. Target Penetration with Metal Liner Devices Using Sensitized Nitromethane Liquid Explosive  

Microsoft Academic Search

In an attempt to overcome the inconsistencies of plastic explosivefilled shape charges in EOD operations we have explored the use of sensitized gelled nitromethane liquid as a filling for a number of shaped charge devices. The ability to penetrate munition casings and induce deflagration is not only dependent on the velocity of detonation of the mixture, investigated in previous papers,

Michael Cartwright; David Lloyd-Roach; Peter J. Simpson

2009-01-01

173

EPDM plasticizers  

SciTech Connect

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

Godail, M.J.

1983-08-01

174

On the seismic response to overdriven explosions  

SciTech Connect

The teleseismic amplitude resulting from an underground explosion is proportional to the asymptotic value of the reduced displacement potential ({phi}{infinity}) or, in physical terms, to the permanent change in volume measured anywhere beyond the range at which the outgoing wave has become elastic. It is known that {phi}{infinity} decreases with increasing initial cavity size (r{sub o}) until the cavity is large enough to preclude inelastic behavior in the surrounding rock, at which point no further decrease occurs. For overdriven explosions, where r{sub o} {yields} O, the behavior is less well understood. It has recently been shown that, in this limit, and for a Hooke's Law, perfectly plastic material, {phi}{infinity}/W{proportional to} (r{sub o}W{sup {minus}1/3}){sup 3-3/{gamma}}, where W is the explosive yield and {gamma} is the polytropic exponent of the driver gas in the cavity. This implies that {phi}{infinity} vanishes altogether as r{sub o} {yields} O. The physical explanation for this curious result is discussed in this paper and extension is made to more realistic material models. Calculations of explosions in salt are compared with the results of the SALMON experiment.

Glenn, L.A.

1991-11-18

175

On the seismic response to overdriven explosions  

SciTech Connect

The teleseismic amplitude resulting from an underground explosion is proportional to the asymptotic value of the reduced displacement potential ({phi}{infinity}) or, in physical terms, to the permanent change in volume measured anywhere beyond the range at which the outgoing wave has become elastic. It is known that {phi}{infinity} decreases with increasing initial cavity size (r{sub o}) until the cavity is large enough to preclude inelastic behavior in the surrounding rock, at which point no further decrease occurs. For overdriven explosions, where r{sub o} {yields} O, the behavior is less well understood. It has recently been shown that, in this limit, and for a Hooke`s Law, perfectly plastic material, {phi}{infinity}/W{proportional_to} (r{sub o}W{sup {minus}1/3}){sup 3-3/{gamma}}, where W is the explosive yield and {gamma} is the polytropic exponent of the driver gas in the cavity. This implies that {phi}{infinity} vanishes altogether as r{sub o} {yields} O. The physical explanation for this curious result is discussed in this paper and extension is made to more realistic material models. Calculations of explosions in salt are compared with the results of the SALMON experiment.

Glenn, L.A.

1991-11-18

176

Plastic Surgery  

Microsoft Academic Search

\\u000a Comprehensive cancer centers in the United States interweave subspecialty care from multiple disciplines. These centers very\\u000a existence is testimony to the broad interdisciplinary approach to cancer care today. Plastic surgery, with its ability to\\u000a restore form and function, represents a small but critical component of the comprehensive care of patients with cancer. Plastic\\u000a surgical reconstruction extends the capabilities of surgery

Neil A. Fine; Charles E. Butler

177

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

178

Simulation of high explosive explosion using adaptive material point method  

Microsoft Academic Search

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

Shang Ma; Xiong Zhang; Yanping Lian; Xu Zhou

2009-01-01

179

Performance evaluation of HSLA steel subjected to underwater explosion  

NASA Astrophysics Data System (ADS)

Performance evaluation of High Strength Low Alloy (HSLA) steel subjected to underwater explosion is of interest to materials engineers because of its structural applications in ships and submarines. Circular and rectangular plates were investigated for their explosive response because they represent panels of a ships plating. Underwater explosion bulge tests were carried out with increasing shock intensity on 4 mm thick circular plates of 290 mm diameter and rectangular plates of 300250 mm to study the plastic deformation and the onset of fracture. Empirical models were developed for the prediction of depth of bulge of the plates. A fresh set of tests with various explosive charge quantities and stand offs were carried out which showed good agreement with the models. Failed edges of the plate showed slant fracture suggesting ductile mode of failure. Scanning Electron Microscopic (SEM) fractographic examination showed dimple features suggesting micro void coalescence.

Rajendran, R.; Narashimhan, K.

2001-02-01

180

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

181

Polymer blends as high explosive binders  

SciTech Connect

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

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

1984-10-05

182

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.

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

1986-05-29

183

Vapor cloud explosion analysis  

SciTech Connect

This paper introduces a new method (now commonly referred to as the Baker-Strehlow Method) for estimating pressure and impulse generated by vapor cloud explosions. Strehlow`s blast curves and concepts from the Multi-Energy method for determination of explosion energy are applied in this technique. New correlations for maximum flame speed based on obstacle density, fuel reactivity, and cloud confinement allow selection of the appropriate blast curve. Application of these correlations removes much of the subjectivity present in existing explosion estimates. 11 refs., 3 figs., 1 tab.

Baker, Q.A. [Wilfred Baker Engineering Inc., San Antonio, TX (United States); Tang, Ming Jun [Nanjing Univ. of Science and Technology (China); Scheier, E.A. [Occidental Chemical Corp., Dallas, TX (United States); Silva, G.J. [Occidental International Exploration & Production CO., Bakersfield, CA (United States)

1996-12-31

184

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

2013-07-23

185

Parametric Explosion Spectral Model  

SciTech Connect

Small underground nuclear explosions need to be confidently detected, identified, and characterized in regions of the world where they have never before occurred. We develop a parametric model of the nuclear explosion seismic source spectrum derived from regional phases that is compatible with earthquake-based geometrical spreading and attenuation. Earthquake spectra are fit with a generalized version of the Brune spectrum, which is a three-parameter model that describes the long-period level, corner-frequency, and spectral slope at high-frequencies. Explosion spectra can be fit with similar spectral models whose parameters are then correlated with near-source geology and containment conditions. We observe a correlation of high gas-porosity (low-strength) with increased spectral slope. The relationship between the parametric equations and the geologic and containment conditions will assist in our physical understanding of the nuclear explosion source.

Ford, S R; Walter, W R

2012-01-19

186

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

187

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

188

Idaho Explosives Detection System  

SciTech Connect

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.

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

2005-12-01

189

Idaho Explosives Detection System  

SciTech Connect

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

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

2004-10-01

190

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

191

Nuclear explosive driven experiments  

SciTech Connect

Ultrahigh pressures are generated in the vicinity of a nuclear explosion. We have developed diagnostic techniques to obtain precise high pressures equation-of-state data in this exotic but hostile environment.

Ragan, C.E.

1981-01-01

192

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

193

Chemical Explosion Database  

NASA Astrophysics Data System (ADS)

A database containing information on chemical explosions, recorded and located by the International Data Center (IDC) of the CTBTO, should be established in the IDC prior to entry into force of the CTBT. Nearly all of the large chemical explosions occur in connection with mining activity. As a first step towards the establishment of this database, a survey of presumed mining areas where sufficiently large explosions are conducted has been done. This is dominated by the large coal mining areas like the Powder River (U.S.), Kuznetsk (Russia), Bowen (Australia) and Ekibastuz (Kazakhstan) basins. There are also several other smaller mining areas, in e.g. Scandinavia, Poland, Kazakhstan and Australia, with large enough explosions for detection. Events in the Reviewed Event Bulletin (REB) of the IDC that are located in or close to these mining areas, and which therefore are candidates for inclusion in the database, have been investigated. Comparison with a database of infrasound events has been done as many mining blasts generate strong infrasound signals and therefore also are included in the infrasound database. Currently there are 66 such REB events in 18 mining areas in the infrasound database. On a yearly basis several hundreds of events in mining areas have been recorded and included in the REB. Establishment of the database of chemical explosions requires confirmation and ground truth information from the States Parties regarding these events. For an explosion reported in the REB, the appropriate authority in whose country the explosion occurred is encouraged, on a voluntary basis, to seek out information on the explosion and communicate this information to the IDC.

Johansson, Peder; Brachet, Nicolas

2010-05-01

194

The Explosion at Bailleul  

Microsoft Academic Search

THE reports referred to in NATURE of August 28 (p. 511) of the effects observed at Denmark Hill, Norwich, and elsewhere by the explosion of a munition dump at Bailleul at 1.10 p.m. G.M.T. on August 8 suggest that these effects were due mainly to earth tremors caused by the explosion, since the rattling of windows, extending in one case

Spencer Pickering

1919-01-01

195

Plastic condoms.  

PubMed

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

1968-01-01

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

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

198

Evaluation of EL836 explosive stimulation of Devonian gas shale  

SciTech Connect

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

Barbour, T.G.

1980-07-01

199

Environmental immunoassay for the explosive RDX using a fluorescent dye-labeled antigen and the continuous-flow immunosensor  

Microsoft Academic Search

To assist in explosives detection for airport security and environmental remediation efforts, a biosensor has been developed at the Naval Research Laboratory based on immunoassays for explosives which are inexpensive, sensitive, and specific for the compound in question. Recently, an analog and antigen-protein complex of the plastic explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) became commercially available. In this report, we present a synthetic

John C. Bart; Linda L. Judd; Anne W. Kusterbeck

1997-01-01

200

Plastics Technician.  

ERIC Educational Resources Information Center

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

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

201

Plastics Technician.  

ERIC Educational Resources Information Center

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

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

202

EPOXY PLASTICS  

Microsoft Academic Search

Practical methods of handling and using some of the many epoxy plastics ; are discussed. Molds, mold-release agents, fillers, diluents, and modifiers are ; described. Mixing, pumping, bonding, equipment required, and toxicity are also ; covered. A collection of formulas is tabulated from which an appropriate type of ; epoxy mixture may be selected. (auth);

J. W. Bryan; R. A. Perkins

1959-01-01

203

Predicting the Effect of Porosity on the Shock Sensitivity of Explosives  

NASA Astrophysics Data System (ADS)

CREST is a reactive-burn model that uses entropy-dependent reaction rates to model shock initiation and detonation behaviour in plastic bonded explosives. A CREST model for the TATB-based high explosive PBX 9502 was published previously at this conference. It is well known that changing the porosity of an explosive, like PBX 9502, can dramatically influence its sensitivity. The equation of state used in CREST incorporates the snow-plough model, allowing the porosity of the explosive to be selected at will, while keeping the reaction model constant. In this paper, it will be shown that CREST can predict the change in explosive sensitivity with porosity, as demonstrated by the experimentally determined Pop-plots for a similar explosive, LX-17. In contrast, it will be shown that pressure-dependent reactive-burn models are unable to predict this porosity effect without changing the reaction rate.

Handley, C. A.; Lambourn, B. D.

2009-12-01

204

Application of the CREST Reactive Burn Model to Two-Dimensional Explosive Experiments  

NASA Astrophysics Data System (ADS)

CREST is a new reactive burn model that uses entropy-dependent reaction rates to model shock initiation and detonation behaviour in plastic bonded explosives. To date the model has been applied to a wide range of shock initiation data obtained from explosive gas-gun experiments where one-dimensional, planar, flat-topped shocks are delivered to the explosive samples. In this paper, to provide a more rigorous test of CREST's predictive capability, the model is applied to two-dimensional explosive experiments where the shock wave entering the explosive departs from the ideal gas-gun case. The calculated results show that the model can simulate the explosive response in shock regimes that are markedly different from truly one- dimensional conditions. This gives confidence in the ability of CREST to simulate a wide range of shock initiation and detonation phenomena.

Whitworth, Nicholas

2007-06-01

205

Detection of Explosive Materials  

NASA Astrophysics Data System (ADS)

High explosives present a challenge for detection methods because of their range of physical properties, which range from volatile liquids to nonvolatile solids. They share the common feature of possessing both oxidizing and reducing chemical properties within a single molecule or an intimate chemical mixture. Our research group has been focused on the synthesis of new luminescent polymers, which undergo electron transfer quenching by a variety of organic high explosives, such as TNT, RDX, and PETN. The application to imaging trace explosive particle residues will be described. Density functional calculations show an excellent correlation between the sensor response and the lowest unoccupied molecular orbital of the explosive analyte. For volatile high explosives, such as organic peroxides (e.g. TATP), vapor sensors based on chemically sensitive transistors containing different metal phthalocyanines have been explored. The mechanism of current response in these films has been shown to be a result of surface Lewis acid-base chemistry or redox catalysis at the metal centers. The link between surface chemistry and electronic resonse has led to a simple peroxide specific vapor sensor array.

Trogler, William

2008-03-01

206

Explosion containment device  

DOEpatents

The disclosure relates to an explosives storage container for absorbing and containing the blast, fragments and detonation products from a possible detonation of a contained explosive. The container comprises a layer of distended material having sufficient thickness to convert a portion of the kinetic energy of the explosion into thermal energy therein. A continuous wall of steel sufficiently thick to absorb most of the remaining kinetic energy by stretching and expanding, thereby reducing the momentum of detonation products and high velocity fragments, surrounds the layer of distended material. A crushable layer surrounds the continuous steel wall and accommodates the stretching and expanding thereof, transmitting a moderate load to the outer enclosure. These layers reduce the forces of the explosion and the momentum of the products thereof to zero. The outer enclosure comprises a continuous pressure wall enclosing all of the layers. In one embodiment, detonation of the contained explosive causes the outer enclosure to expand which indicates to a visual observer that a detonation has occurred.

Benedick, William B. (Albuquerque, NM); Daniel, Charles J. (Albuquerque, NM)

1977-01-01

207

Molecular models for explosives  

SciTech Connect

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

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

1987-01-01

208

Explosively separable casing  

SciTech Connect

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, A.K.; Kychnovsky, R.E.; Visbeck, C.N.

1985-02-19

209

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

210

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

211

Destruction of peroxide explosives.  

PubMed

Chemicals containing multiple peroxide functionalities, such as triacetone triperoxide (TATP), diacetone diperoxide (DADP), or hexamethylene triperoxide diamine (HMTD), can be explosive. They are impractical and are not used by legitimate military groups because they are shock and heat sensitive compared to military explosives. They are attractive to terrorists because synthesis is straightforward, requiring only a few easily obtained ingredients. Physical removal of these synthesis products is highly hazardous. This paper discusses methods to degrade peroxide explosives chemically, at room temperature. A number of mixtures containing metals (e.g., zinc, copper) and metal salts (e.g., zinc sulfate, copper chloride) were found effective, some capable of destroying TATP solutions in a few hours. Strong acids proved useful against solid peroxide materials; however, on a 1 g scale, addition of concentrated sulfuric acid caused TATP to detonate. Thus, this technique should only be used to destroy small-laboratory quantities. PMID:19737243

Oxley, Jimmie C; Smith, James L; Huang, Jiaorong; Luo, Wei

2009-09-01

212

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

213

Loading of wellbores with explosives  

SciTech Connect

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

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

1983-04-26

214

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

215

Microcantilever detector for explosives  

DOEpatents

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

Thundat, Thomas G. (Knoxville, TN)

1999-01-01

216

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

217

extensive plasticity  

Microsoft Academic Search

Experimentally observed crack deflection events in multi-layered material systems, occurring even under pure mode-I loading, are here simulated and explained through elasto-plastic finite element modelling. The crack tip opening displacement is adopted as the crack driving force and estimated along crack paths whose deflection is predicted using the maximum tangential strain criterion. Shielding conditions that promote deflection and bifurcation are

Allan Burke-Veliz; Philippa A. S. Reed; Stavros Syngellakis

218

High Explosives Handbook. Volume 1. Revision 1.  

National Technical Information Service (NTIS)

This High Explosives Handbook provides information related to the design of nuclear systems. This volume contains information on Primary explosives, High explosives, Squibs and Primacord, Adhesives, Fillers, and coatings used with explosives and Solid Pro...

1967-01-01

219

Coal Dust Explosions and Their Suppression.  

National Technical Information Service (NTIS)

Contents: The problem of coal dust explosions; Basic information about the explosibility of coal dust; Main parameters of the explosibility of coal dust; Limit explosibility of coal dust and its dependence upon the basic parameters; The effect of the init...

W. Cybulski

1975-01-01

220

Explosives Test and Evaluation Facilities.  

National Technical Information Service (NTIS)

This report is provided as a reference document for explosive hardware. The successful development of explosive devices used in ordnance or other defense or space application requires a rigorous test and evaluation program to assure high reliability in us...

D. D. Kerstetter

1972-01-01

221

Friction Sensitivity of Primary Explosives.  

National Technical Information Service (NTIS)

A Bundesanstalt fur Materialprufung (BAM) small friction tester, manufactured in West Germany, has been used to rank primary explosives in their order of friction sensitivity. Primary explosives RD 1333 lead azide, dextrinated lead styphnate, polyvinyl-al...

J. Harris

1982-01-01

222

Safe explosives for shaped charges  

Microsoft Academic Search

It was demonstrated that high-performance shaped charges could be developed using as the explosive charge mixtures of ingredients that are not, by themselves, considered explosives. At least one of the ingredients needed to be a liquid, stored separately, that could be quickly injected into the shaped charge cavity to generate the active explosive. Precision copper shaped charge cones in diameters

K. J. Scribner; J. O. Davis

1977-01-01

223

Hand held explosives detection system  

DOEpatents

The present invention is directed to a sensitive hand-held explosives detection device capable of detecting the presence of extremely low quantities of high explosives molecules, and which is applicable to sampling vapors from personnel, baggage, cargo, etc., as part of an explosives detection system.

Conrad, Frank J. (Albuquerque, NM)

1992-01-01

224

Electromagnetic field effects in explosives  

Microsoft Academic Search

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: measurements of conductivity; enhancement of performance; and control of initiation and growth of reaction. Hayes...()^1 showed a strong correlation of peak electrical conductivity with carbon content of

Douglas Tasker

2009-01-01

225

Explosives signatures and analysis  

Microsoft Academic Search

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

Jonathan M. Oyler

2008-01-01

226

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

227

Bioremediation of Explosive Contaminants  

Microsoft Academic Search

This paper discusses several methods currently available for the treatment of nitramine- type explosive contaminants in soil environments as well give a brief description of several research projects that were recently conducted in this area. The review begins by first discussing where RDX, HMX, TNT and CL-20 contaminants come from and what avenues through which they can travel to enter

Matt Mahler

228

Explosions and blast injuries  

Microsoft Academic Search

Powerful explosions have the potential to inflict many different types of injuries on victims, some of which may be initially occult. Flying debris and high winds commonly cause conventional blunt and penetrating trauma. Injuries caused by blast pressures alone result from complex interactions on living tissues. Interfaces between tissues of different densities or those between tissues and trapped air result

John M. Wightman; Sheri L. Gladish

2001-01-01

229

Explosions During Galaxy Formation  

NASA Astrophysics Data System (ADS)

As an idealized model of the effects of energy release by supernovae during galaxy formation, we consider an explosion at the center of a halo which forms at the intersection of filaments in the plane of a cosmological pancake by gravitational instability during pancake collapse. Such halos resemble the virialized objects found in N-body simulations in a CDM universe and, therefore, serve as a convenient, scale-free test-bed model for galaxy formation. ASPH/P3M simulations reveal that such explosions are anisotropic. The energy and metals are channeled into the low density regions, away from the pancake plane. The pancake remains essentially undisturbed, even if the explosion is strong enough to blow away all the gas located inside the halo at the onset of the explosion and reheat the IGM surrounding the pancake. Infall quickly replenishes this ejected gas and gradually restores the gas fraction as the halo mass continues to grow. Estimates of the collapse epoch and SN energy-release for galaxies of different mass in the CDM model can relate these results to scale-dependent questions of blow-out and blow-away and their implication for early IGM heating and metal enrichment and the creation of dark-matter-dominated dwarf galaxies.

Martel, H.; Shapiro, P. R.

2001-03-01

230

Ecotoxicology of Explosives  

Microsoft Academic Search

Managing sites contaminated with munitions constituents is an international challenge. Although the choice of approach and the use of Ecological Risk Assessment (ERA) tools may vary from country to country, the assurance of quality and the direction of ecotoxicological research are universally recognized as shared concerns. Drawing on a multidisciplinary team of contributors, 'Ecotoxicology of Explosives' provides comprehensive and critical

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

2009-01-01

231

CBC: Halifax Explosion  

NSDL National Science Digital Library

In the evening of December 6, 1917, a massive explosion rocked the harbor of the rapidly growing city of Halifax, Nova Scotia, located in eastern Canada. Caused by the collision of two ships (one of which was carrying a tremendous amount of explosive material), the explosion killed over 1500 people outright, and devastated the settlements around the area. Working with various historical groups, the Canadian Broadcasting Corporation has created this engrossing multimedia look into the events leading up to that dreadful incident, along with offering a broader historical perspective on the development of the city of Halifax and the aftermath of these tragic events. Starting from the main page, visitors will learn about Halifax's history, along with having the opportunity to view significant interactive features, such as maps of the area and recently-discovered archival footage of the city and its environs. The interactive features here are quite amazing, as visitors can view video clips of survivors' recollections, and watch footage of various commemoration activities associated with the explosion.

232

LLNL explosives handbook: properties of chemical explosives and explosives and explosive simulants  

Microsoft Academic Search

This handbook presents information and data for high explosives (HEs) of interest to programs at the Lawrence Livermore National Laboratory (LLNL) and other Department of Energy (DOE) facilities. It is intended to be useful to the scientist or engineer, the novice or expert, who needs to develop a new weapon system, design a physics experiment, or select and\\/or evaluate an

Dobratz

1981-01-01

233

The combustion of explosives  

SciTech Connect

The safe use of energetic materials has been scientifically studied for over 100 years. Even with this long history of scientific inquiry, the level of understanding of the important deflagration phenomena in accidental initiations of high explosives remains inadequate to predict the response to possible thermal and mechanical (impact) scenarios. The! search also continues for more well behaved explosives and propellants that perform well, yet are insensitive. Once ignition occurs in an explosive, the question then becomes what the resulting violence will be. The classical view is that simple wave propagation proceeds from the ignition point. Recently, several experiments have elucidated the importance of reactive cracks involved in reaction violence in both thermally ignited experiments and impacted explosives, in contrast to classical assumptions, This work presents a viiw of reaction violence, in both thermal and mechanical insults, that argues for the importance of reactive cracks, rather than simple wave propagation processes. Recent work in this area will be reviewed and presented. Initial results involving novel energetic materials will also be discussed.

Son, S. F. (Steven F.)

2001-01-01

234

Hydrogen explosion testing with a simulated transuranic drum  

SciTech Connect

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

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

1990-01-01

235

Hydrogen explosion testing with a simulated transuranic drum  

SciTech Connect

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

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

1990-12-31

236

DOE explosives safety manual. Revision 1  

SciTech Connect

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 divided into the following sections: introduction, operational safety, explosives and personnel limits and personnel control, training, quantity-distance and level of protection criteria for explosives activities, operating procedures, formulation scaleup, and insensitive high explosives qualification. (DLC)

Not Available

1983-12-01

237

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

238

Anaerobic Metabolism and Bioremediation of Explosives-Contaminated Soil  

Microsoft Academic Search

\\u000a Nitroaromatic compounds pollute soil, water, and food via use of pesticides, plastics, pharmaceuticals, landfill dumping of\\u000a industrial wastes, and the military use of explosives. Biotransformation of trinitrotoluene and other nitroaromatics by aerobic\\u000a bacteria in the laboratory has been frequently reported, but the anaerobic bacterial metabolism of nitroaromatics has not\\u000a been studied as extensively perhaps due to the difficulty in working

Raj Boopathy

2009-01-01

239

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

240

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

241

Critical temperature analysis for a hemispherical charge of a binary explosive  

Microsoft Academic Search

The adiabatic induction period for a hemispherical charge of a binary explosive (13.9 wt % pentaerythritol tetranitrate (PETN) and 86.1 wt % plastic bonded explosive (PBX9407)) enclosed in an aluminum\\/ceramic housing was measured by conventional cook-off tests over the temperature range of 150 to 250°C. Simulated adiabatic induction time curves for an intimate mixture of PETN and PBX9407 were recorded

Pickard

1989-01-01

242

Biodegradation of nitro-explosives.  

PubMed

Environmental contamination by nitro compounds is associated principally with the explosives industry. However, global production and use of explosives is unavoidable. The presently widely used nitro-explosives are TNT (Trinitrotoluene), RDX (Royal Demolition Explosive) and HMX (High Melting Explosive). Nevertheless, the problems of these nitro-explosives are almost parallel due to their similarities of production processes, abundance of nitro-explosives and resembling chemical structures. The nitro-explosives per se as well as their environmental transformation products are toxic, showing symptoms as methaemoglobinaemia, kidney trouble, jaundice etc. Hence their removal/degradation from soil/water is essential. Aerobic and anaerobic degradation of TNT and RDX have been reported, while for HMX anaerobic or anoxic degradation have been described in many studies. A multisystem involvement using plants in remediation is gaining importance. Thus the information about degradation of nitro-explosives is available in jigsaw pieces which needs to be arranged and lacunae filled to get concrete degradative schemes so that environmental pollution from nitro-explosives can be dealt with more successfully at a macroscale. An overview of the reports on nitro-explosives degradation, future outlook and studies done by us are presented in this review. PMID:15242292

Kanekar, Pradnya; Dautpure, Premlata; Sarnaik, Seema

2003-09-01

243

Development of ammonium nitrate based explosives to optimize explosive properties and explosive welding parameters used during explosion cladding  

NASA Astrophysics Data System (ADS)

The ability to accurately measure and predict the velocity of explosively driven flyer plates has been a subject of significant work by the explosives community for some time. The majority of this work has focused on the use of high-energy, ideal explosives that are of interest for defense applications. Several attempts have been made to modify the experimental methods developed for these ideal explosives for use in testing low-energy, non-ideal explosive compounds (including industrially useful mixtures of ammonium nitrate, fuels, and additives) with varying degrees of success. The detonation properties of non-ideal explosives are difficult to measure precisely due to the effect of physical, environmental, and geometric factors on the detonation of these materials. The work presented in this document attempts to mitigate the variability inherent in measurements of non-ideal, ammonium nitrate-based explosives by performing testing using charge geometry similar to that used in the industrial process of explosion welding. A method to measure flyer plate velocity with optical high-speed imaging using commercially available equipment is described. Flyer plate velocity data from both experimental measurements and numerical modeling is presented. A new formula for predicting explosive energy based on the detonation velocity of an ammonium nitrate based explosive in a planar geometry is proposed and applied to a theoretical explosive cladding scenario.

Hurley, Christoph

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

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

246

Mechanical Failure Properties of Composite Plastic Bonded >>>>>Explosives  

Microsoft Academic Search

The initial part of the uniaxial stress versus strain response in compression can be described in terms of a modulus, E, a peak stress, gammam (a failure stress) and a strain at the peak stress, ?m (a failure strain). gammam increases in proportion to E for smaller values of E and in proportion to E^1\\/2 for larger values with changes

Donald Wiegand

1997-01-01

247

Surface properties of potential plastic-bonded explosives (PBX)  

SciTech Connect

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 between polymer and TATB are computed based on the experimental data. Resulting values can be used as a scale to evaluate potential TATB binders. 13 references, 4 tables.

Rivera, T.; Matuszak, M.L.

1983-05-01

248

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

249

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

250

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

251

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

252

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

253

Cast aluminized explosives (review)  

Microsoft Academic Search

This paper reviews the current status and future trends of aluminized explosives. The major focus is on cast compositions,\\u000a which encompass both the melt-cast trinitrotoluene (TNT) based and the slurry cast polymer-based compositions. Widely reported\\u000a RDX and HMX based aluminized compositions with TNT used as a binder are discussed in detail. Various researchers have suggested\\u000a a 1520% Al content as

P. P. Vadhe; R. B. Pawar; R. K. Sinha; S. N. Asthana; A. Subhananda Rao

2008-01-01

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

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

2013-05-17

256

Non-Shock Initiation Model for Explosive Families: Experimental Results  

NASA Astrophysics Data System (ADS)

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

Anderson, M. U.; Todd, S. N.; Caipen, T. L.; Jensen, C. B.; Hughs, C. G.

2009-12-01

257

Dislocation Theory of Plasticity.  

National Technical Information Service (NTIS)

Based on the observation that plastic behavior is a macroscopic manifestation of the motion and interaction of dislocations, a plasticity theory is proposed that represents a connecting link between solid state physics and the conventional plasticity and ...

H. T. Hahn W. Jaunzemis

1971-01-01

258

Ferromagnetic Porous Plastics.  

National Technical Information Service (NTIS)

This claim concerns a process for producing a ferromagnetic porous plastic. The ferromagnetic porous plastic is obtained by mixing a plastic with finely powdered ferromagnetic material and then foaming the mixture in the presence of a foaming agent. Detai...

M. Moriya K. Hosoda M. Takai

1983-01-01

259

Post explosion analysis of explosives by mass spectrometric methods  

Microsoft Academic Search

The Analysis of trace amounts of explosives from post-explosion debrisone of the most difficult problems in forensic chemistry-is still carried out in many laboratories by chromatographic methods only. In recent years several new methods have been applied to the analysis of explosives. These include mass spectrometric methods (GC\\/MS, LC\\/MS and MS\\/MS) and NMR methods. The possible application of these methods

Shmuel Zitrin

1986-01-01

260

Numerical Modeling of Underwater Explosion Properties for Nonideal Explosives  

NASA Astrophysics Data System (ADS)

Underwater experiments for an ideal explosive, TNT, and two nonideal explosives, CETR emulsion and DXD-04, were performed, and numerically simulated. For TNT, calculations done by using program-burn models based on the rate-independent Chapman-Jouguet theory were in a good agreement with experimental results, which validated the wide use of program-burn models for ideal explosives. For CETR emulsion and DXD-04, experimental observations could be reproduced with high precision only when reaction rates were employed. These results demonstrated that detonation in nonideal explosives can be modeled only by using properly calibrated reaction rates.

Lee, Jaimin

261

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

262

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

263

Calibration methods for explosives detectors  

NASA Astrophysics Data System (ADS)

Airport security has become an important concern to cultures in every corner of the world. Presently, efforts to improve airport security have brought additional technological solutions, in the form of advanced instrumentation for the detection of explosives, into use at airport terminals in many countries. This new generation of explosives detectors is often used to augment existing security measures and provide a more encompassing screening capability for airline passengers. This paper describes two calibration procedures used for the Thermedics' EGIS explosives detectors. The systems were designed to screen people, electronic components, luggage, automobiles, and other objects for the presence of concealed explosives. The detectors have the ability to detect a wide range of explosives in both the vapor state or as surface adsorbed solids, therefore, calibrations were designed to challenge the system with explosives in each form.

MacDonald, Stephen J.; Rounbehler, David P.

1992-05-01

264

Prompt Reaction of Aluminum in Detonating Explosives  

SciTech Connect

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

Sandusky, H. W.; Granholm, R. H. [NAVSEA Indian Head Division, Indian Head MD 20640 (India)

2006-07-28

265

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

Federal Register 2010, 2011, 2012, 2013

...Initiating tube systems. K KDNBF [potassium dinitrobenzo-furoxane...Nitroguanidine explosives. Nitronium perchlorate propellant mixtures. Nitroparaffins...composition. Pentolite. Perchlorate explosive mixtures. Peroxide...Picrate explosives. Picrate of potassium explosive mixtures....

2012-09-20

266

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

Federal Register 2010, 2011, 2012, 2013

...Initiating tube systems. K KDNBF [potassium dinitrobenzo-furoxane...Nitroguanidine explosives. Nitronium perchlorate propellant mixtures. Nitroparaffins...composition. Pentolite. Perchlorate explosive mixtures. Peroxide...Picrate explosives. Picrate of potassium explosive mixtures....

2011-10-19

267

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

Federal Register 2010, 2011, 2012, 2013

...Initiating tube systems. K KDNBF [potassium dinitrobenzo-furoxane...Nitroguanidine explosives. Nitronium perchlorate propellant mixtures. Nitroparaffins...composition. Pentolite. Perchlorate explosive mixtures. Peroxide...Picrate explosives. Picrate of potassium explosive mixtures....

2010-11-17

268

75 FR 1085 - Commerce in Explosives; List of Explosive Materials (2009R-18T)  

Federal Register 2010, 2011, 2012, 2013

...Initiating tube systems. K KDNBF [potassium dinitrobenzo-furoxane...Nitroguanidine explosives. Nitronium perchlorate propellant mixtures. Nitroparaffins...composition. Pentolite. Perchlorate explosive mixtures. Peroxide...Picrate explosives. Picrate of potassium explosive mixtures....

2010-01-08

269

Suppression Effect on Explosive Percolation  

NASA Astrophysics Data System (ADS)

Percolation transitions (PTs) of networks, leading to the formation of a macroscopic cluster, are conventionally considered to be continuous transitions. However, a modified version of the classical random graph model was introduced in which the growth of clusters was suppressed, and a PT occurs explosively at a delayed transition point. Whether the explosive PT is indeed discontinuous or continuous becomes controversial. Here, we show that the behavior of the explosive PT depends on detailed dynamic rules. Thus, when dynamic rules are designed to suppress the growth of all clusters, the discontinuity of the order parameter tends to a finite value as the system size increases, indicating that the explosive PT could be discontinuous.

Cho, Y. S.; Kahng, B.

2011-12-01

270

Spectral analysis on explosive percolation  

NASA Astrophysics Data System (ADS)

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

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

2013-03-01

271

Explosive scabbling of structural materials  

DOEpatents

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

Bickes, Jr., Robert W. (Albuquerque, NM); Bonzon, Lloyd L. (Albuquerque, NM)

2002-01-01

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

Intrinsic fluctuations in explosive reactions  

SciTech Connect

A reaction is called explosive when the amount of a reactant becomes infinite in a finite time. When the intrinsic stochastic character of the reaction is taken into account, the explosion time is a random quantity. The authors compute its probability distribution, or at least its average and variance, for various kinds of reactions. If a reaction is unstable, so that a reactant can either explode or disappear, one first has to compute the probability for an explosion to occur at all, and then the average explosion time. Finally, the same ideas are applied to more general Markov processes.

van Kampen, N.G.

1987-03-01

274

Low voltage nonprimary explosive detonator  

DOEpatents

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

275

Zirconium hydride containing explosive composition  

DOEpatents

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

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

1981-01-01

276

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

277

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

278

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

2013-06-17

279

Explosions on the Sun  

NASA Astrophysics Data System (ADS)

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

Harra, Louise K.

2005-10-01

280

Explosive Turbulent Magnetic Reconnection  

NASA Astrophysics Data System (ADS)

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.

Higashimori, K.; Yokoi, N.; Hoshino, M.

2013-06-01

281

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

282

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

283

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

284

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

2000-01-01

285

77 FR 55108 - Explosive Siting Requirements  

Federal Register 2010, 2011, 2012, 2013

...the storage and handling of energetic liquids and explosives. DATES: Effective November...site where solid propellants, energetic liquids, or other explosives are located to prepare...quantity of solid propellants, energetic liquids, and other explosives located...

2012-09-07

286

14 CFR 420.63 - Explosive siting.  

Code of Federal Regulations, 2013 CFR

...each public area, including the launch site boundary; (2) A list of the maximum quantity of energetic liquids, solid propellants and other explosives to be located at each explosive hazard facility, including explosive class and division;...

2013-01-01

287

Explosives Detection for Aviation Security  

NASA Astrophysics Data System (ADS)

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.

Fainberg, Anthony

1992-03-01

288

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

289

Explosive Sensing Using Polymer Lasers  

Microsoft Academic Search

Conjugated polymers are attractive materials that have been used to make a wide range of optoelectronic devices. Recently they have been used as explosive sensors as there is currently an urgent need for high sensitivity explosive detection due to the increased security issues across the world. This review outlines the attractive properties of organic polymers as gain media in lasers,

Yue Wang; Ying Yang; Graham A. Turnbull; Ifor D. W. Samuel

2012-01-01

290

Applying NASA's Explosive SEAM Welding.  

National Technical Information Service (NTIS)

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...

L. J. Bement

1991-01-01

291

NONMILITARY USES OF NUCLEAR EXPLOSIONS  

Microsoft Academic Search

Conversion of the sudden release of energy in explosions at ertremely ; high temperature and pressure into the form of useful work, either mechanical, ; chemical, or thermal, must be accomplished in order for such explosions to have ; nomailitary uses. The technical feasibility of such conversion in a number of ; different instances is discussed along with nuisance effects.

1960-01-01

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

Explosive-Powder Compaction System.  

National Technical Information Service (NTIS)

Sandia National Laboratories has developed a pressure-control system and a test fixture to study the behavior of explosive materials during compaction. Both the pressure-control system and the test fixture are self-contained and portable. Explosive materi...

A. P. Montoya M. L. Reichenbach

1981-01-01

294

TRENDS IN NUCLEAR EXPLOSION MONITORING  

Microsoft Academic Search

Nuclear explosion monitoring is as important today as it was at the dawn of the atomic age. Over the past several decades the scientific understanding and technological sophistication that underpin monitoring have advanced tremendously. We still face challenges, however, because the United States (U.S.) needs to monitor a growing range of events, from earthquakes to mining explosions that can cause

Dale N. Anderson; Raymond J. Willemann; Harry S. Miley; C. L. Edwards; Preston B. Herrington; J. Mark Harris; Joseph C. Wehlburg; David B. Harris; John J. Zucca; Leslie A. Casey

295

Explosive detection research and development  

Microsoft Academic Search

The detection of explosives carried by a passenger or included in checked baggage is a priority objective of the Federal Aviation Administration's (FAA) Security Research and Development Program. Significant accomplishments have been made in the detection of explosives in checked baggage. A technology, thermal neutron analysis, has been developed and tested extensively in airports with actual passenger baggage. The screening

Malotky

1988-01-01

296

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

Microsoft Academic Search

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

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

1996-01-01

297

The recovery of DNA profiles from saliva and touch evidences after postal bomb explosion  

Microsoft Academic Search

Terrorist crime usually makes use of improvised explosive disposals (IEDs) which, especially in national environments, consist of postal or pipe bombs often assembled by using plastic or paper envelopes, adhesive tapes, electric components such as switches, batteries, cables, etc. To date it has been considering quite complex to recover DNA in quality and quantity proper for STRs typing aimed at

A. Berti; F. Barni; A. Virgili; C. Colozza; F. Maiorino; M. Tocca

298

Predictive simulation and experimental confirmation of the onset of instability of explosively driven shells  

Microsoft Academic Search

The detonation of explosives with thin shells can cause the shells to expand to over 200% strain at strain rates on the order of 10 s before failure. Experimental data indicate the development and growth of multiple plastic instabilities lead to the formation of failure and fragmentation in the near periodic pattern. Presented are comparisons of the onset of instabilities

Mark L Potocki; Lawrence M Hull

2010-01-01

299

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

NASA Astrophysics Data System (ADS)

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

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

1999-08-01

300

Trace Explosive Detection Using Nanosensors  

SciTech Connect

Selective and sensitive detection of explosives is very important in countering terrorist threats. Detecting trace explosives has become a very complex and expensive endeavor because of a number of factors, such as the wide variety of materials that can be used as explosives, the lack of easily detectable signatures, the vast number of avenues by which these weapons can be deployed, and the lack of inexpensive sensors with high sensitivity and selectivity. High sensitivity and selectivity, combined with the ability to lower the deployment cost of sensors using mass production, is essential in winning the war on explosives-based terrorism. Nanosensors have the potential to satisfy all the requirements for an effective platform for the trace detection of explosives.

Senesac, Larry R [ORNL; Thundat, Thomas George [ORNL

2008-01-01

301

On the violence of thermal explosion in solid explosives  

SciTech Connect

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

Chidester, S.K.; Tarver, C.M.; Green, L.G.; Urtiew, P.A. [Lawrence Livermore National Lab., CA (United States). Defense Technologies Engineering Div.

1997-07-01

302

Nucleosynthesis in stellar explosions  

SciTech Connect

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

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

1983-01-01

303

Explosive molecular ionic crystals.  

PubMed

In ionic crystals of the form M(+)X(-), certain covalently bonded anion groups X(-) are particularly associated with instability. The heavier metal cations M(+) enhance this. Very sensitive explosives occur within the extended azide family, where X(-) = CNO(-), N(3)(-), NCO(-), or NCS(-) (an isoelectronic set of unsaturated linear triatomic anions). Another such family are the globular oxyanions X(-) = ClO(2)(-), ClO(3)(-), ClO(4)(-), NO(3)(-), and MnO(4)(-). Mishandling of NH(4)NO(3) or NH(4)ClO(4) has caused major disasters. An irreversible cyclic mechanism is proposed for such decomposition, involving mechanoelectronic band-gap excitation and coalescence of X with X(-). From an intracrystalline ion-molecule collision complex, the singly charged dianion X(2)(-), exothermic reactions proceed with high yield. PMID:17787990

Faust, W L

1989-07-01

304

Thermochemistry of mixed explosives  

SciTech Connect

In order to predict thermal hazards of high-energy materials, accurate kinetics constants must be determined. Predictions of thermal hazards for mixtures of high-energy materials require measurements on the mixtures, because interactions among components are common. A differential-scanning calorimeter (DSC) can be used to observe rate processes directly, and isothermal methods enable detection of mechanism changes. Rate-controlling processes will change as components of a mixture are depleted, and the correct depletion function must be identified for each specific stage of a complex process. A method for kinetics measurements on mixed explosives can be demonstrated with Composition B is an approximately 60/40 mixture of RDX and TNT, and is an important military explosive. Kinetics results indicate that the mator process is the decomposition of RDX in solution in TNT with a perturbation caused by interaction between the two components. It is concluded that a combination of chemical kinetics and experimental self-heating procedures provides a good approach to the production of predictive models for thermal hazards of high-energy materials. Systems involving more than one energy-contributing component can be studied. Invalid and dangerous predictive models can be detected by a failure of agreement between prediction and experiment at a specific size, shape, and density. Rates of thermal decomposition for Composition B appear to be modeled adequately for critical-temperature predictions with the following kinetics constants: E = 180.2 kJ mole/sup -1/ and Z = 4.62 X 10/sup 16/ s/sup -1/.

Janney, J.L.; Rogers, R.N.

1982-01-01

305

Direct imaging of explosives.  

PubMed

Any technique that can detect nitrogen concentrations can screen for concealed explosives. However, such a technique would have to be insensitive to metal, both encasing and incidental. If images of the nitrogen concentrations could be captured, then, since form follows function, a robust screening technology could be developed. However these images would have to be sensitive to the surface densities at or below that of the nitrogen contained in buried anti-personnel mines or of the SEMTEX that brought down Pan Am 103, approximately 200 g. Although the ability to image in three-dimensions would somewhat reduce false positives, capturing collateral images of carbon and oxygen would virtually assure that nitrogenous non-explosive material like fertilizer, Melmac dinnerware, and salami could be eliminated. We are developing such an instrument, the Nitrogen Camera, which has met experimentally these criteria with the exception of providing oxygen images, which awaits the availability of a sufficiently energetic light source. Our Nitrogen Camera technique uses an electron accelerator to produce photonuclear reactions whose unique decays it registers. Clearly if our Nitrogen Camera is made mobile, it could be effective in detecting buried mines, either in an active battlefield situation or in the clearing of abandoned military munitions. Combat operations require that a swathe the width of an armored vehicle, 5 miles deep, be screened in an hour, which is within our camera's scanning speed. Detecting abandoned munitions is technically easier as it is free from the onerous speed requirement. We describe here our Nitrogen Camera and show its 180 pixel intensity images of elemental nitrogen in a 200 g mine simulant and in a 125 g stick of SEMTEX. We also report on our progress in creating a lorry transportable 70 MeV electron racetrack microtron, the principal enabling technology that will allow our Nitrogen Camera to be deployed in the field. PMID:11003510

Knapp, E A; Moler, R B; Saunders, A W; Trower, W P

306

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

307

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

308

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

309

Radiologic diagnosis of explosion casualties.  

PubMed

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

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

310

Application of the Crest Reactive Burn Model to Two-Dimensional PBX 9502 Explosive Experiments  

NASA Astrophysics Data System (ADS)

CREST is a new reactive burn model that uses entropy-dependent reaction rates to model shock initiation and detonation behaviour in plastic bonded explosives. To date the model has been successfully applied to a wide range of one-dimensional shock initiation data obtained from explosive gas-gun experiments. In this paper, to provide a more rigorous test of CREST's predictive capability, the model is applied to two-dimensional explosive detonation propagation experiments. The calculated results show that the CREST reaction rate model, fitted only to one-dimensional data of the shock to detonation transition, can accurately simulate two-dimensional explosive data from detonation experiments. This gives confidence in the ability of the model to accurately predict a wide range of shock initiation and detonation phenomena.

Whitworth, N. J.

2007-12-01

311

An Eulerian algorithm for coupled simulations of elastoplastic-solids and condensed-phase explosives  

NASA Astrophysics Data System (ADS)

The performance of non-ideal condensed-phase explosives depends on the nature of the confiner material as well as the charge itself, so the accurate modelling of this confiner and its interaction with the explosive allows for improved performance predictions. Traditionally, numerical methods for solving such multi-material problems have used Lagrangian or mixed Eulerian-Lagrangian approaches, but recent advances in numerical methods for coupling CFD (Computational Fluid Dynamics) and CMD (Computational Material Dynamics) algorithms has made such coupled simulations possible in the Eulerian frame of reference. However, to date, the explosive material representation within these simulations has been restricted to the single-phase Euler equations. In the present study we couple a multi-phase chemically-active model for condensed-phase explosives to an elastic-plastic model for inert confiner materials.

Schoch, Stefan; Nordin-Bates, Kevin; Nikiforakis, Nikolaos

2013-11-01

312

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

SciTech Connect

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

Martineau, R.L.; Prime, M.B.; Anderson, C.A. [Los Alamos National Lab., NM (United States); Smith, F.W. [Colorado State Univ., Fort Collins, CO (United States)

1999-04-01

313

The evolution of microstructural changes in pressed HMX explosives  

SciTech Connect

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

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

1998-12-31

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

Base hydrolysis and hydrothermal processing of PBX-9404 explosive  

SciTech Connect

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

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

1994-12-31

316

Explosion and Explosives. Volume 32, Number 2, 1971.  

National Technical Information Service (NTIS)

Contents: Economic progress and safety; Lead salt of mono-di - and tri-nitro resorcinol (Report II, sensitivity characteristic and some other properties); Observation on detonation phenomenon in rectangular cartridge by x-ray flash method; Explosive nitra...

1971-01-01

317

High Explosive Radio Telemetry System  

SciTech Connect

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

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

1998-11-04

318

Explosive Microsphere Particle Standards for Trace Explosive Detection Instruments  

NASA Astrophysics Data System (ADS)

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

Staymates, Matthew; Fletcher, Robert; Gillen, Greg

2007-11-01

319

Metaplasticity: the plasticity of synaptic plasticity  

Microsoft Academic Search

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

Wickliffe C. Abraham; Mark F. Bear

1996-01-01

320

New plastic joints for plastic orthoses  

Microsoft Academic Search

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

H. WATANABE; T. KUTSUNA; H. MORINAGA; T. OKABE

321

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

322

Studies on explosively driven cracks under confining in-situ stresses  

SciTech Connect

Successful explosive gas well stimulation requires a thorough understanding of explosively driven cracks under confining in-situ stresses. In a previous paper (Simha, et al 1983) the problem of explosively driven cracks was experimentally investigated to reveal the features of crack propagation. It was observed that the explosively driven crack propagation is the result of two different but overlapping phases. The first phase involving the initiation and early time crack propagation is entirely governed by the explosively generated stress transients. The rapidly decaying stress transients then lead to the second phase of crack propagation largely controlled by the in-situ stresses. The purpose of this paper is to more fully understand the characteristics of the first phase concerning the initiation and early time propagation of explosively driven cracks. Experiments are conducted with plastic models under biaxial compression and the dynamic event is observed with a high speed multiple spark gap camera of the Cranz-Schardin type. The experimental observations are utilized to propose analytical models of crack initiation under explosive loading to aid in the design of multiple fracturing necessary for successful application of modern well stimulation techniques. 8 references, 4 figures.

Simha, K.R.Y.; Fourney, W.L.; Dick, R.D.

1984-01-01

323

Study on Plastic Pipes.  

National Technical Information Service (NTIS)

District heating pipelines are usually placed by using medium pipes consisting of steel; it is only in some exceptional cases that plastics are used. In future, plastics could be used for district heating subdistribution in competition with steel pipes pr...

A. Tautz

1982-01-01

324

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

325

Plastics in Solid Waste.  

National Technical Information Service (NTIS)

Plastics are being used for a variety of purposes, including packaging, because of their physical characteristics. The volume of plastics produced per year is increasing, and the production process involves thousands of facilities throughout the Nation. M...

1971-01-01

326

Plastic surgery in Hull  

Microsoft Academic Search

The nineteenth of a series of histories of Plastic Surgery Centres adapted, when necessary, by A. F. Wallace and C. W. Chapman from records forming part of the Archives of the British Association of Plastic Surgeons.

M. H. Heycock

1995-01-01

327

Plastic Surgery in Aberdeen  

Microsoft Academic Search

The twentieth of a series of histories of UK Plastic Surgery Centres adapted, when necessary, by A. F. Wallace and C. W. Chapman from records forming part of the Archives of the British Association of Plastic Surgeons.

I. F. K. Muir

1995-01-01

328

Rdx, HMX and Explosive Compositions.  

National Technical Information Service (NTIS)

Chemical properties, physical properties, and specification requirements are given for cyclonite (RDX) and homocyclonite (HMX). Also included is a list of explosive compositions produced from RDX, HMX, TNT, and various binding agents. The latter listing i...

1965-01-01

329

Nuclear explosives for peaceful purposes  

SciTech Connect

The US Plowshare programme, designed to develop peaceful uses of nuclear explosives, was vigorous between 1957 to 1973 and was of concern during US and USSR nuclear treaty negotiations within that period. In order to accommodate possible future applications, the Peaceful Nuclear Explosions (PNE) Treaty was signed in 1976. The US programme explored the phenomenology of nuclear explosions and tested their use in industrial applications. Due to waning industrial interest and public concern over environmental issues, the US program was terminated in 1977. The Soviet counterpart to the Plowshare programme, which has involved roughly 100 experiments throughout the USSR, continued until the self-imposed moratorium in 1985. As any peaceful use of nuclear explosives has the potential of furthering weapons research, the US takes the position that all such experiments would have to be banned in a comprehensive test ban treaty (CTBT).

Borg, I.Y.

1986-07-01

330

Nuclear explosives for peaceful purposes  

SciTech Connect

The US Plowshare program, designed to develop peaceful uses of nuclear explosives, was vigorous between 1957-73 and was of concern during US and USSR nuclear treaty negotiations within that period. In order to accommodate possible future applications, the Peaceful Nuclear Explosions Treaty was signed in 1976. The US program explored the phenomenology of nuclear explosions and tested their use in industrial applications. Due to waning industrial interest and public concern over environmental issues, the US program was terminated in 1977. The Soviet counterpart to the Plowshare program, which has involved more than 100 experiments throughout the USSR, continued until the self-imposed moratorium in 1985. As any peaceful use of nuclear explosives has the potential of furthering weapons research, the US takes the position that all such experiments would have to be banned in a comprehensive test ban treaty. 24 refs.

Borg, I.Y.

1986-11-01

331

Detonation probabilities of high explosives  

SciTech Connect

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

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

1995-07-01

332

Risk Management of Explosives Storage.  

National Technical Information Service (NTIS)

The use of Quantitative Risk Assessment (QRA) procedures to manage the safety and control of explosives has been stimulated by ever increasing demands for more efficient operation, and by the requirements of recently extended Health and Safety Legislation...

D. J. Hewkin G. B. Jones I. Self R. A. Drake V. J. Gill

1994-01-01

333

Fundamental Research in Explosive Magnetohydrodynamics.  

National Technical Information Service (NTIS)

The background experimental work with explosive driven MHD generators is reviewed and the major parametric factors are outlined. Previously unpublished data on the effects of the density and composition of gases originally in the channel is reviewed and i...

M. S. Jones

1976-01-01

334

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

335

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.

Marsh, Stanley P. (Los Alamos, NM)

1988-01-01

336

Calculations for Explosive Magnetic Generators.  

National Technical Information Service (NTIS)

This is a translation of a Soviet paper which develops generalized criteria for optimum design of an explosive magnetic generator. Studies on techniques for pulsed compression of magnetic fields, with the resultant high pulse power generation, were active...

S. G. Hibben

1976-01-01

337

Plasticity, plasticity, plasticityand the rigid problem of sex.  

PubMed

Why is popular understanding of female-male differences still based on rigid models of development, even though contemporary developmental sciences emphasize plasticity? Is it because the science of sex differences still works from the same rigid models? PMID:24176517

Fine, Cordelia; Jordan-Young, Rebecca; Kaiser, Anelis; Rippon, Gina

2013-11-01

338

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

339

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

340

On coupling factors of explosion  

NASA Astrophysics Data System (ADS)

The question of the seismic effect of an explosion plays an important part in the theory and practice of demolition engineering, antiseismic engineering, nuclear explosion engineering, seismic exploration, and seismic depth sounding. A still unresolved issue in this regard is concerned with the calculation of energy conversion process. An attempt is made to explore this issue by drawing on the research done in the field of seismic depth sounding.

Shao-Quan, Z.

1985-04-01

341

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)

2010-06-29

342

Gas explosion during diathermy gastrotomy.  

PubMed

The first report of rupture of the stomach due to diathermy-elicited gas explosion during gastrotomy in a patient with intestinal ischemia resulting in obstruction and jejunal and gastric dilatation is presented. In the obstructed stomach or small bowel, a proliferation of hydrogen- and methane-producing bacteria can occur, leading to the accumulation of these combustible gases in explosive concentrations. In cases of gastrointestinal tract obstruction, the diathermy knife should not be used in entering the gastrointestinal lumen. PMID:2910765

Joyce, F S; Rasmussen, T N

1989-02-01

343

Explosive-powder compaction system  

Microsoft Academic Search

Sandia National Laboratories has developed a pressure-control system and a test fixture to study the behavior of explosive materials during compaction. Both the pressure-control system and the test fixture are self-contained and portable. Explosive materials are compacted in a bridged header charge holder assembly by means of a test fixture and a pneumatic cylinder arrangement. Forces are measured with load

A. P. Montoya; M. L. Reichenbach

1981-01-01

344

External ballistic of volcanic explosions  

Microsoft Academic Search

In order to determine the kinetic energy of an explosion it is necessary to know the initial velocities of ejected fragments.\\u000a \\u000a Calculations of initial velocities made earlier with few exceptions did not take into account the resistance of the air and\\u000a therefore, greatly underestimated the initial velocities, and consequently the energy of the explosions. A solution of the\\u000a inverse problem

G. S. Steinberg; V. Lorenz

1983-01-01

345

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

Skeist, Irving, Ed.

346

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

347

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

348

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.

349

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

350

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

351

Microbial remediation of explosive waste.  

PubMed

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

Singh, Baljinder; Kaur, Jagdeep; Singh, Kashmir

2012-05-01

352

Explosive Characteristics of Carbonaceous Nanoparticles  

NASA Astrophysics Data System (ADS)

Explosion testing has been performed on 20 codes of carbonaceous particles. These include SWCNTs (single-walled carbon nanotubes), MWCNTs (multi-walled carbon nanotubes), CNFs (carbon nanofibers), graphene, diamond, fullerene, carbon blacks and graphites. Explosion screening was performed in a 20 L explosion chamber (ASTM E1226-10 protocol), at a (dilute) concentration of 500 g/m^3, using a 5 kJ ignition source. Time traces of overpressure were recorded. Samples exhibited overpressures of 5-7 bar, and deflagration index KSt = V^1/3 (dp/pt)max 10 - 80 bar-m/s, which places these materials in European Dust Explosion Class St-1 (similar to cotton and wood dust). There was minimal variation between these different materials. The explosive characteristics of these carbonaceous powders are uncorrelated with particle size (BET specific surface area). Additional tests were performed on selected materials to identify minimum explosive concentration [MEC]. These materials exhibit MEC 10^1 -10^2 g/m^3 (lower than the MEC for coals). The concentration scans confirm that the earlier screening was performed under fuel-rich conditions (i.e. the maximum over-pressure and deflagration index exceed the screening values); e.g. the true fullerene KSt 200 bar-m/s, placing it borderline St-1/St-2.

Turkevich, Leonid; Fernback, Joseph; Dastidar, Ashok

2013-03-01

353

Estimates of Crater Dimensions for Near-Surface Explosions of Nuclear and High-Explosive Sources.  

National Technical Information Service (NTIS)

Crater data from numerous high-explosive (HE) experiments and from fewer nuclear explosive (NE) tests are used to develop an empirically based procedure for predicting crater dimensions from nuclear explosions in various geologic media. The HE crater data...

H. F. Cooper

1976-01-01

354

Biodegradability of plastics.  

PubMed

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

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

2009-08-26

355

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

356

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

357

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

358

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

359

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

360

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

361

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

362

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

363

FEM analysis of escape capsule suffered to gas explosion  

NASA Astrophysics Data System (ADS)

Escape capsules are new devices for underground coal mines that provide air, water, food and supplies in the event of an emergency in where miners are unable to escape. It is difficult to carry out the experiments of explosion and safety because the danger and nonrepeatability of explosion. The structure deformation and distribution of equivalent stress has been investigated under different impact pressure conditions including unimodal and bimodal loads based on the FEM and software LS-DYNA. The results show that the distribution of deformation and equivalent stress has the same trend on the same surface with the increment of explosion pressure. The deformation and stress are larger with side impact pressure compared with that of the same front impact pressure. Furthermore, the maximum equivalent stress is 246MPa and 260MPa on the front and sides of capsule with five times for national standard impact pressure 1.5MPa. Under these conditions, the deformation is less than about 9.97mm and 10.47mm, respectively. When the front impact pressure is 2.0MPa, the deformation of capsule still belongs to elasticity but the less plastic deformation occurs on the Ushape stiffening channels with the same side impact pressure. However, it is safe for capsule structure because the equivalent stress 283MPa is much less than the tensile strength. It is noted that bimodal load accelerates the capsule deformation so that it is more dangerous compared with unimodal load.

Li, Chang-lu; Mei, Rui-bin; Li, Chang-sheng; Cai, Ban; Liu, Xiang-hua

2013-05-01

364

Microscopic Approaches to Decomposition and Burning Processes of a Micro Plastic Resin Particle under Abrupt Heating  

NASA Astrophysics Data System (ADS)

To elucidate the possibility and availability of thermal recycling of waste plastic resin from a basic and microscopic viewpoint, a series of abrupt heating processes of a spherical micro plastic particle having a diameter of about 200 ?m is observed, when it is abruptly exposed to hot oxidizing combustion gas. Three ingenious devices are introduced and two typical plastic resins of polyethylene terephthalate and polyethylene are used. In this paper the dependency of internal and external appearances of residual plastic embers on the heating time and the ingredients of plastic resins is optically analyzed, along with appearances of internal micro bubbling, multiple micro explosions and jets, and micro diffusion flames during abrupt heating. Based on temporal variations of the surface area of a micro plastic particle, the apparent burning rate constant is also evaluated and compared with those of well-known volatile liquid fuels.

Ohiwa, Norio; Ishino, Yojiro; Yamamoto, Atsunori; Yamakita, Ryuji

365

Our plastic age  

PubMed Central

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

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

2009-01-01

366

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

367

Nonequilibrium detonation of composite explosives  

SciTech Connect

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

Nichols III, A.L.

1997-07-01

368

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.

369

The plastics waste problem  

Microsoft Academic Search

Post-consumer plastic is a symptom of the municipal solid waste (MSW) problem, not the cause. Yet the U.S. public sees plastic as a major contributor to the waste stream. Two-thirds say the environmental risks of using plastics outweigh the benefits and that they favor mandatory recycling programs in their community; more than four-fifths think recycling can substantially reduce the amount

Rowatt

1993-01-01

370

PLASTIC FIBER ROLLINGFOR CONCRETEREINFORCEMENT  

Microsoft Academic Search

ABSTRACT Fiber reinforced concrete is gaining in acceptance and usage as its strength and toughness,benefits are realized. Polypropylene fibers are currently the most commonly,used fibers. However~,the cost of virgin plastics limits the percent content that can be economically,added to concrete. One would,first believe that recycled plastics could offer a viable alternative to virgin-plastic fibers, but at present time extra selection

JEFF SCOTT THOMAS

1996-01-01

371

Brain plasticity and tumors  

Microsoft Academic Search

Brain plasticity is the potential of the nervous system to reshape itself during ontogeny, learning or following injuries.\\u000a The first part of this article reviews the pathophysiological mechanisms underlying plasticity at different functional levels.\\u000a Such plastic potential means that the anatomo-functional organization of the brain in humans, both physiological and pathological,\\u000a has flexibility. Patterns of reorganization may differ according to

H. Duffau; Gui de Chauliac; CHU de Montpellier; CNRS FRE; Boulogne Billancourt

372

The plastics waste problem  

SciTech Connect

Post-consumer plastic is a symptom of the municipal solid waste (MSW) problem, not the cause. Yet the U.S. public sees plastic as a major contributor to the waste stream. Two-thirds say the environmental risks of using plastics outweigh the benefits and that they favor mandatory recycling programs in their community; more than four-fifths think recycling can substantially reduce the amount of solid waste and decry the presence of nonbiodegradable plastics in landfills. Given this perception, the author reviews solid waste management issues and examines the contributions that resin producers can make.

Rowatt, R.J.

1993-01-01

373

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

374

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

375

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

376

30 CFR 56.6102 - Explosive material storage practices.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Explosive material storage practices. 56.6102 Section 56.6102...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Storage § 56.6102 Explosive material storage practices. (a) Explosive material...

2013-07-01

377

29 CFR 1910.109 - Explosives and blasting agents.  

Code of Federal Regulations, 2010 CFR

...Explosive-actuated power devices. Explosive-actuated power deviceany tool or special mechanized...proximity to other explosives. Tools used for opening packages...storage of any metal tools nor any commodity except explosives, but this...

2007-07-01

378

29 CFR 1910.109 - Explosives and blasting agents.  

Code of Federal Regulations, 2010 CFR

...Explosive-actuated power devices. Explosive-actuated power deviceany tool or special mechanized...proximity to other explosives. Tools used for opening packages...storage of any metal tools nor any commodity except explosives, but this...

2008-07-01

379

29 CFR 1910.109 - Explosives and blasting agents.  

Code of Federal Regulations, 2010 CFR

...Explosive-actuated power devices. Explosive-actuated power deviceany tool or special mechanized...proximity to other explosives. Tools used for opening packages...storage of any metal tools nor any commodity except explosives, but this...

2011-07-01

380

29 CFR 1910.109 - Explosives and blasting agents.  

Code of Federal Regulations, 2010 CFR

...Explosive-actuated power devices. Explosive-actuated power deviceany tool or special mechanized...proximity to other explosives. Tools used for opening packages...storage of any metal tools nor any commodity except explosives, but this...

2006-07-01

381

29 CFR 1910.109 - Explosives and blasting agents.  

Code of Federal Regulations, 2010 CFR

...Explosive-actuated power devices. Explosive-actuated power deviceany tool or special mechanized...proximity to other explosives. Tools used for opening packages...storage of any metal tools nor any commodity except explosives, but this...

2012-07-01

382

29 CFR 1910.109 - Explosives and blasting agents.  

Code of Federal Regulations, 2010 CFR

...Explosive-actuated power devices. Explosive-actuated power deviceany tool or special mechanized...proximity to other explosives. Tools used for opening packages...storage of any metal tools nor any commodity except explosives, but this...

2005-07-01

383

Study on Surface Initiation of Explosives.  

National Technical Information Service (NTIS)

In response to a continued military demand for controlled explosive wave shaping, this study was undertaken to establish basic conditions and to demonstrate the feasibility of an explosive system capable of being initiated uniformly along its entire surfa...

J. Roth

1966-01-01

384

46 CFR 188.10-25 - Explosive.  

Code of Federal Regulations, 2012 CFR

...GENERAL PROVISIONS Definition of Terms Used in This Subchapter § 188.10-25 Explosive. This term means a chemical compound or mixture, the primary purpose of which is to function by explosion; i.e. , with substantially...

2012-10-01

385

46 CFR 188.10-25 - Explosive.  

Code of Federal Regulations, 2011 CFR

...GENERAL PROVISIONS Definition of Terms Used in This Subchapter § 188.10-25 Explosive. This term means a chemical compound or mixture, the primary purpose of which is to function by explosion; i.e. , with substantially...

2011-10-01

386

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

387

EUExNet - A European Explosives Network.  

National Technical Information Service (NTIS)

An understanding of explosives science and technology, and the competence to harness it is central to maintaining Explosives capability, national security, and in sustaining a competitive industry. A consequence of eroding this competence is the increased...

E. Nilsson H. Wallin

2010-01-01

388

Military Engineering Application of Commercial Explosives.  

National Technical Information Service (NTIS)

Explosive excavation is a relatively new technology for creating barriers, destroying targets, and constructing military aids (e.g., bunker emplacements) in the theater of operations. This technology stems from research in explosive excavation performed s...

J. Briggs

1972-01-01

389

Polyurethane Binder Systems for Polymer Bonded Explosives.  

National Technical Information Service (NTIS)

Polymer bonded explosives (PBXs) consist of explosive components bound together by a polymeric binder. The most common binder systems in current PBXs are polyurethane based and contain plasticisers and other chemicals that alter processability, mechanical...

M. A. Daniel

2006-01-01

390

Underwater Explosion Bubble Jetting Effects on Infrastructure.  

National Technical Information Service (NTIS)

Underwater explosions present a significant risk to structures because they were not designed for these types of loads and because water transmits explosive energy much more efficiently than air. The US Navy demonstrated that the effect of bubble jetting ...

G. Chahine G. Harris J. Fortune J. L. O'Daniel R. Ilamni

2011-01-01

391

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

392

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

393

Pulsed Power to Energize Explosive Replacements  

Microsoft Academic Search

Summary form only given. We have developed an electrically-activated replacement for explosives called Metafexreg (for metal-fueled explosive replacement) that is inert until activated and twice as energetic as conventional explosives such as RDX. Because it is inert until activated (a moment before use), it offers profound logistics advantages over conventional explosives. Activation of Metafex requires a significant, short-duration electrical pulse.

D. Davison; R. Johnson; D. Pratt

2006-01-01

394

Numerical simulation of underwater explosion loads  

Microsoft Academic Search

Numerical simulation of TNT underwater explosion was carried out with AUTODYN software. Influences of artificial viscosity\\u000a and mesh density on simulation results were discussed. Detonation waves in explosive and shock wave in water during early\\u000a time of explosion are high frequency waves. Fine meshes (less than 1,mm) in explosive and water nearby, and small linear viscosity\\u000a coefficients and quadratic viscosity

Chunliang Xin; Gengguang XU; Kezhong Liu

2008-01-01

395

On the geophysical fingerprint of Vulcanian explosions  

NASA Astrophysics Data System (ADS)

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

Gottsmann, J.; de Angelis, S.; Fournier, N.; van Camp, M.; Sacks, S.; Linde, A.; Ripepe, M.

2011-06-01

396

Miniaturization of Explosive Technology and Microdetonics  

Microsoft Academic Search

Condensed phase explosives used in conventional explosive systems have a charge size on the order of a meter or a sizable fraction of a meter. We discuss a range of issues, theoretical, computational and experimental, required to scale the size of explosive systems downwards by a factor of one hundred to one thousand, applications and prospects for a ubiquitous new

D. Scott Stewart

397

Towards the miniaturization of explosive technology  

Microsoft Academic Search

Condensed phase explosives used in conventional explosive systems have a charge size on the order of a meter or a sizable fraction of a meter. This paper addresses a range of issues required to scale downwards the size of explosive systems by a factor of one hundred to one thousand.

D. S. Stewart

2002-01-01

398

Towards the miniaturization of explosive technology  

Microsoft Academic Search

. Condensed phase explosives used in conventional explosive systems have a charge size on the order of a meter or a sizable\\u000a fraction of a meter. This paper addresses a range of issues required to scale downwards the size of explosive systems by a\\u000a factor of one hundred to one thousand.

D. S. Stewart

2002-01-01

399

46 CFR 153.921 - Explosives.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Explosives. 153.921 Section 153.921 ...Operational Requirements § 153.921 Explosives. No person may load, off-load...this part on board a vessel that carries explosives unless he has the prior written...

2011-10-01

400

46 CFR 153.921 - Explosives.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Explosives. 153.921 Section 153.921 ...Operational Requirements § 153.921 Explosives. No person may load, off-load...this part on board a vessel that carries explosives unless he has the prior written...

2012-10-01

401

Explosive composition containing high density hydrocarbon liquid  

Microsoft Academic Search

A blasting composition is composed of a mixture of inorganic nitrate, e.g., ammonium nitrate, and a high density hydrocarbon liquid. This explosive has more explosive force than an equal volumetric amount of a mixture of ammonium nitrate and diesel fuel. The latter is a commercial explosive currently used in large quantities. A high-density hydrocarbon liquid is one having a density

W. L. Borkowski; A. Schneider

1977-01-01

402

78 FR 1143 - Explosive Siting Requirements; Correction  

Federal Register 2010, 2011, 2012, 2013

...Amdt. No. 420-6A] RIN 2120-AJ73 Explosive Siting Requirements; Correction AGENCY...regulations to the requirements for siting explosives under a license to operate a launch...and handling of energetic liquids and explosives. The FAA inadvertently did not...

2013-01-08

403

Explosives detection with hard-wired moths  

Microsoft Academic Search

A prototype system that uses moths to detect explosives was designed, assembled, and tested. It compares the electromyographic signals of moths trained to respond or not respond to a target explosive vapor in order to determine whether or not explosive devices, such as bombs or landmines, are present. The device was designed to be portable by making it lightweight, battery-powered,

T. L. King; Frank Moore Horine; K. C. Daly; Brian H. Smith

2003-01-01

404

Suppressants for the control of industrial explosions  

Microsoft Academic Search

Explosion suppression is now a well established means of mitigation against the consequences of a gas or dust explosion in industrial processing. Such systems were first deployed by Graviner Ltd (Maisey, H.R. Chem. Process Eng., March 1959) in the early 1950s following development of the technology for military purposes. The first industrial explosion suppression systems used proprietary halons as the

P. E. Moore

1996-01-01

405

Firing complex for explosive pulsed power  

Microsoft Academic Search

A modern firing complex has been constructed for the dedicated development and application of explosive pulsed power (i.e., flux compression generators). The complex consists of three underground and interconnected buildings. The buildings, which employ several types of structural design, are engineered for above ground, open air detonations involving up to 1000 kg (TNT-equivalent) of high explosive. The explosive rating is

D. J. Erickson; B. L. Freeman; J. E. Vorthman; R. S. Caird; C. M. Fowler; J. C. King; A. R. Martinez; J. V. Repa; J. B. VanMarter; R. G. Vaughn

1986-01-01

406

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

407

Explosive fracturing and propping of petroleum wells  

Microsoft Academic Search

A method is described of stimulating the flow of petroleum fluids in a well. Explosive fracturing of the petroleum formation adjacent to the well is carried out in the presence of a propping agent, such as glass beads, sand or aluminum particles. The propping agent-explosive combination is preferably surrounded by granular ammonium nitrate explosive to insure the absence of voids

Lozanski

1973-01-01

408

Supernova explosions in the Universe  

Microsoft Academic Search

During the lifetime of our Milky Way galaxy, there have been something like 100 million supernova explosions, which have enriched the Galaxy with the oxygen we breathe, the iron in our cars, the calcium in our bones and the silicon in the rocks beneath our feet. These exploding stars also influence the birth of new stars and are the source

Adam Burrows

2000-01-01

409

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

410

Underwater explosions and cavitation phenomena  

Microsoft Academic Search

Some aspects of underwater explosions and cavitation phenomena have been studied by using a thermodynamic equation of state for water and a one-dimensional Lagrangian hydrocode. The study showed that surface cavitation is caused by the main blast wave and a bubble pulse from rebound of a release wave moving toward the center of the exploding bubble. Gravity has little effect

Kamegai

1979-01-01

411

Fires and explosions in substations  

Microsoft Academic Search

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

D. J. Allan

2002-01-01

412

IONOSPHERIC EFFECTS OF NUCLEAR EXPLOSIONS  

Microsoft Academic Search

Dieminger and Kohl (Nature, 193: 983(1982)) described some ionospheric ; phenomena observed at Lindau, Germany, on October 30, 1961, following a large ; nuclear explosion at Novaya Zemlya in the arctic. Since the recordings were made ; at 1\\/2-hourly intervals, the precise time of the onset of the disturbance could ; not be pinpointed. For a large part of the

W. J. G. Beynon; E. S. O. Jones

1962-01-01

413

Numerical simulation of underground explosions  

Microsoft Academic Search

This paper presents a numerical method to calculate stress wave propagation in rock mass and to estimate damage zone around an underground borehole generated by explosion. Numerical calculations are carried out by using a commercial software AUTODYN2D, which is a finite difference code with Lagrange, Euler and combined Lagrange-Euler processors, and is especially suitable for modelling high velocity nonlinear dynamic

Hong Hao; Guowei Ma; Yingxin Zhou

1998-01-01

414

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

415

Mound calorimetry for explosive surveillance  

SciTech Connect

Heat of reaction determinations of pyrotechnics and explosives is made at MRC-Mound by bomb calorimetry. Energy releases from ten calories to 94 kilocalories have been measured accurately using four different calorimeter systems. Each system is described and some heat of reaction results are given. 3 figs., 4 tabs.

Shockey, G.C.; Rodenburg, W.W.

1985-01-01

416

Neutrino mechanism of supernova explosion  

Microsoft Academic Search

In the last decades, scientifics have tried to understand the explosion mechanism of stars that is responsible for the simultaneous formation of neutron star and supernova outburst.The main problem is the determination of a source of energy in the ejection of a supernova envelope. The gravitation energy as a source of energy in supernova is placed first. However, subsequent studies

V. M. Chechetkin

1997-01-01

417

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

418

Numerical Simulations of Thermobaric Explosions  

SciTech Connect

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

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

2007-05-04

419

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

420

Transuranic drum hydrogen explosion tests  

SciTech Connect

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

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

1991-06-01

421

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

422

Plastic bag suffocation  

Microsoft Academic Search

Summary The circumstances of suffocation by plastic bags are reviewed and illustrated, in the main, by cases which were investigated by the Department of Forensic Medicine, University of Leeds. There is a continuing need to draw attention to the hazards created by the wide-spread use of plastic bags for packaging.

C. J. Polson; D. J. Gee

1972-01-01

423

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

424

Extruded Plastic Scintillation Detectors  

Microsoft Academic Search

As a way to lower the cost of plastic scintillation detectors, commercially available polystyrene pellets have been used in the production of scintillating materials that can be extruded into different profiles. The selection of raw materials is discussed. Two techniques to add wavelength shifting dopants to polystyrene pellets and to extrude plastic scintillating strips are described. Data on light yield

Anna Pla-Dalmau; Alan D. Bross; Kerry L. Mellott

1999-01-01

425

Extruded plastic scintillation detectors  

Microsoft Academic Search

As a way to lower the cost of plastic scintillation detectors, commercially available polystyrene pellets have been used in the production of scintillating materials that can be extruded into different profiles. The selection of the raw materials is discussed. Two techniques to add wavelength shifting dopants to polystyrene pellets and to extrude plastic scintillating strips are described. Data on light

Anna Pla-Dalmau; Alan D. Bross; Kerry L. Mellott

1999-01-01

426

Laser Cutting Plastic Materials.  

National Technical Information Service (NTIS)

A 1000-watt CO sub 2 laser has been demonstrated as a reliable production machine tool for cutting of plastics, high strength reinforced composites, and other nonmetals. More than 40 different plastics have been laser cut, and the results are tabulated. A...

R. A. Van Cleave

1980-01-01

427

STRESS AND HIPPOCAMPAL PLASTICITY  

Microsoft Academic Search

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

Bruce S. McEwen

1999-01-01

428

Localization of plastic deformation  

Microsoft Academic Search

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

J. Rice

1976-01-01

429

Degradable jute plastic composites  

Microsoft Academic Search

A urethane prepolymer with an aliphatic chain, has been used to prepare a number of formulations, in the presence of plasticizers and monomers of different characteristics. Hessian cloth (jute product) is coated with these formulations and cured under u.v. radiation. Tensile properties (strength and elongation) of the jute plastic composite, thus formed with these formulations were found to increase. The

M. Khabir Uddin; Mubarak A. Khan; K. M. Idriss Ali

1997-01-01

430

Cell fusion and plasticity  

Microsoft Academic Search

Cell plasticity is a central issue in stem cell biology. In many recent discussions, observation of cell fusion has been seen\\u000a as a confounding factor which calls into question published results concerning cell plasticity of, particularly, adult stem\\u000a cells. An examination of the voluminous literature of \\

Joseph J. Lucas; Naohiro Terada

2003-01-01

431

Plasticity in fretting contact  

Microsoft Academic Search

The fretting problem of a cyclically loaded cylinder on a flat elasticplastic surface is analyzed under the assumption of plane strain. Severe fretting conditions are modeled by applying a constant normal load and a cyclic tangential load to the cylinder and describing the contact behavior using a Coulomb friction law. Detailed numerical results are presented for the evolution of plastic

J. M. Ambrico; M. R. Begley

2000-01-01

432

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

433

Effects of crystal plasticity on materials loaded at high pressures and strain rates  

Microsoft Academic Search

A crystal plasticity model is used to examine the effects of grain microstructure on the local deformation of metals subjected to high pressure and high strain rate loading characteristic of ballistic impact, explosive loading and laser ablation. The crystal elastic moduli are pressure dependent to capture the large volume strains properly and to enable evolution of shocks from steep pressure

R Becker

2004-01-01

434

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

Microsoft Academic Search

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

Karin E. Sorra; Kristen M. Harris

2000-01-01

435

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

Microsoft Academic Search

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

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

1996-01-01

436

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

437

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

438

Explosive shocks in air (2nd edition)  

NASA Astrophysics Data System (ADS)

After an initial qualitative characterization of the properties of explosions in the atmosphere and their blast and shock propagation effects, attention is given to the underlying quantitative principles of explosive energy release, including the scaling laws for explosions and internal blast effects from confined explosions. The dynamic loads that blast waves impose on representative structures are then characterized, with attention to resulting structural damage. A major feature of the present treatment is the use of the dimensionless Mach number in all shock equations; a further simplification is furnished by first developing mathematical equations for shock in steady flow, and then applying these equations to explosive shock by simple transformation of coordinates.

Kinney, G. F.; Graham, K. J.

439

Image analysis of explosives fingerprint contamination using a Raman imaging spectrometer  

NASA Astrophysics Data System (ADS)

The characterization of the type and quanity of explosives residue left behind as fingerprints is critical for the problem of trace explosives detection as well as forensic investigation. A nondestructive analytical technique has to be used to identify the energetic component of the explosive from the plasticizers, dyes, and fingerprint oils that make up the background. Raman microspectroscopy has been demonstrated in the past to separate explosive particulate from other residue in a microscopic image by filtering out other spectra except the region of the strong bands displayed by PETN and RDX using He-Ne excitation. In addition, gray level/measurements have been done on features of the sample, captured under white light onto a CCD, to obtain quantitative data about size and volume distribution. The objective of this paper will be to show how integrated line images of the sample, captured with high spectral resolution using a scanning Raman spectrometer, can be used to separate out components in the image scene captured by the CCD. This paper will also show how confocal scanning through the depth of the sample, while taking an image, can be used to come up with a quantitative measure of the concentration of chosen components in the entire image. The special instrumentation used for the work will be shown as well as any modifications done to it to obtain a protocol for analysis. The image analysis results will be presented of actual fingerprint samples containing plastic explosives. The variance between the Raman imaging method and other more traditional destructive methods for doing quantitative analysis will be presented. And the probability of doing direct Raman microspectroscopy in the UV region without any background subtraction will be determined for its potential for doing in-situ analysis for explosives detection.

Mercado, Alvaro G.; Janni, James; Gilbert, Brian

1995-09-01

440

Calorimetry studies of explosion heat of non-ideal explosives  

Microsoft Academic Search

Heats of explosion of non-ideal RDX-based compositions in four various atmospheres (argon, nitrogen, air and argon\\/oxygen\\u000a mixture) were measured. Charges of phlegmatized RDX containing 30% of two types of aluminium powders, coarse aluminium oxide,\\u000a or fine lithium fluoride particles were fired in a calorimetric bomb of 5.6 dm3 in volume. The influence of inert and reactive additives and the atmosphere

W. Kici?ski; W. A. Trzci?ski

2009-01-01

441

Sensitivity to friction for primary explosives.  

PubMed

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

Maty, Robert; eleovsk, Jakub; Musil, Tom

2012-02-03

442

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

443

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

444

Liquids and homemade explosive detection  

NASA Astrophysics Data System (ADS)

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

Ellenbogen, Michael; Bijjani, Richard

2009-05-01

445

Megatrends Affecting Plastics  

NSDL National Science Digital Library

Stephen DeHoff of Stress Engineering Services (SES) Product Development and Engineering created this presentation for the Innovative Technologies Symposium for Plastics in 2007. This presentation discusses the overall economic trends that are affecting plastic development and manufacturing. Oil supply, alternative energy sources, labor force, GDP growth, globalization, US fiscal and demographic issues are some of the topics touched upon. DeHoff ends his presentation with suggestions for molders to sustain and develop successful businesses in the current plastics environment. He advocates creativity and change in an otherwise generally pessimistic market.

Dehoff, Stephen

2010-10-20

446

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

447

The entropy in supernova explosions  

SciTech Connect

The explosion of a supernova forms because of the collapse to a neutron star. In addition an explosion requires that a region of relatively high entropy be in contact with the neutron star and persisting for a relatively protracted period of time. The high entropy region ensures that the maximum temperature in contact with the neutron star and in hydrostatic equilibrium is less than some maximum. This temperature must be low enough such that neutrino emission cooling is small, otherwise the equilibrium atmosphere will collapse adding a large accretion mass to the neutron star. A so-called normal explosion shock that must reverse the accretion flow corresponding to a typical stellar collapse must have sufficient strength or pressure to reverse this flow and eject the matter with 10{sup 51} ergs for a typical type II supernova. Surprisingly the matter behind such a shock wave has a relatively low entropy low enough such that neutrino cooling would be orders of magnitude faster than the expansion rate. The resulting accretion low would be inside the Bondi radius and result in free-fall accretion inside the expanding rarefaction wave. The accreted mass or reimplosion mass unless stopped by a high entropy bubble could than exceed that of bound neutron star models. In addition the explosion shock would be overtaken by the rarefaction wave and either disappear or at least weaken. Hence, a hot, high entropy bubble is required to support an equilibrium atmosphere in contact with a relatively cold neutron star. Subsequently during the expansion of the high entropy bubble that drives or pushes on the shocked matter, mixing of the matter of the high entropy bubble and lower entropy shock-ejected matter is ensured. The mixing is driven by the negative entropy gradient between the high entropy bubble accelerating the shocked matter and the lower entropy of the matter behind the shock.

Colgate, S.A.

1990-12-06

448

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

449

Data base of chemical explosions in Kazakhstan  

SciTech Connect

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

Demin, V.N. [National Nuclear Center of Republic of Kazakhstan Institute of Geophysical Researches (Kazakhstan); Malahova, M.N. [National Nuclear Center of Republic of Kazakhstan Institute of Geophysical Researches (Kazakhstan); Martysevich, P.N. [National Nuclear Center of Republic of Kazakhstan Institute of Geophysical Researches (Kazakhstan); Mihaylova, N.N. [National Nuclear Center of Republic of Kazakhstan Institute of Geophysical Researches (Kazakhstan); Nurmagambetov, A. [National Nuclear Center of Republic of Kazakhstan Institute of Geophysical Researches (Kazakhstan); Kopnichev, Yu.F. D. [National Nuclear Center of Republic of Kazakhstan Institute of Geophysical Researches (Kazakhstan); Edomin, V.I. [National Nuclear Center of Republic of Kazakhstan Institute of Geophysical Researches (Kazakhstan)

1996-12-01

450

Intravesical explosions during transurethral endoscopic procedures.  

PubMed

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

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

2006-12-14

451

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

452

Plastic encapsulated parts.  

National Technical Information Service (NTIS)

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 w...

T. Castillo

1994-01-01

453

Energetic Polynitro Formal Plasticizers.  

National Technical Information Service (NTIS)

Plasticizers which are commonly used in gun propellants and other energetic compositions are nitroglycerin (NG), butanetriol trinitrate (BTTN), metriol trinitrate (METN), diethylene glycol dinitrate (DEGN), and bis (2,2-dinitropropyl) formal/acetal (BDNPF...

H. D. Adolph K. E. Kim

1987-01-01

454

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

2012-12-18

455

Plastic Sewers - Calculating Deformation.  

National Technical Information Service (NTIS)

Deformation of the more flexible plastic pipes increasingly used for sewers presents a new problem; hence the need for accurately assessing strengths. Laboratory and field work by the Hungarian Institute for Building Science considered the calculation met...

I. Dezsenyi

1975-01-01

456

Inelastic Behavior of Plastics.  

National Technical Information Service (NTIS)

The overall objective of this project has been to develop increased understanding of the mechanical behavior of plastics such as polyethylene. Improved understanding of its mechanical behavior may permit improvements in fabrication and testing procedures ...

J. H. Weiner

1980-01-01

457

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

458

Strength of Plastics.  

National Technical Information Service (NTIS)

Results are presented of studies of the resistance of reinforced and unreinforced structural plastics to static and fatigue failure. Attention is devoted to the formation and development of brittle fracture of plexiglas and polystyrene with account for th...

S. V. Serensen V. S. Strelyaev Y. Nemets

1973-01-01

459

Computer Techniques for Plasticity.  

National Technical Information Service (NTIS)

Implicit in the development of any plasticity model are assumptions associated with the behavior of the actual material. Assumptions generally employed are listed with a discussion of their implications. Several models that incorporate these assumptions o...

H. Armen A. Pifko

1979-01-01

460

Plasticity and Variable Heredity.  

National Technical Information Service (NTIS)

The operational definition of variable heredity is compared with that of rate-dependence and they are shown to be unrelated indicative that 'fading memory' and 'plasticity' do not necessarily exclude each other. The problems of characterizing materials wi...

E. Krempl

1978-01-01

461

Plastic Packaging Consortium Plastic Package Thermal Dissipation  

Microsoft Academic Search

The Plastic Packaging Consortium (PPC), a Technology Reinvestment Project (TRP) funded by DARF'A under SOL 94-27 addresses the needs to build up and strengthen an on-shore infrastructure for thermally enhanced, ruggedized, and high density packages. The intention of the program is to identify the cost-of-ownership for the various combinations of package enhancements with respect to the performance level achieved so

Daniel Tracy; Luu Nguyen; R. Glberti; Anthony Gallo; C. Bischo; C. J. Jonczrrk; J. Wohlin

1997-01-01

462

Caspases in synaptic plasticity.  

PubMed

Caspases are a family of cysteine proteases that play key roles in programmed cell death (apoptosis). Mounting evidence in recent years shows that caspases also have important non-apoptotic functions in multiple cellular processes, such as synaptic plasticity, dendritic development, learning and memory. In this article, we review the studies on the non-apoptotic functions of caspases in neurons, with a focus on their roles in synaptic plasticity, learning and memory and neurodegeneration. PMID:22583788

Li, Zheng; Sheng, Morgan

2012-05-14

463

Laser cutting plastic materials  

SciTech Connect

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

Van Cleave, R.A.

1980-08-01

464

Plastic pipe testing techniques  

Microsoft Academic Search

As gas-distribution companies increasingly install polyethylene plastic piping, both the users and the producers of polyethylene will need to develop methods to predict the plastic's service-life expectancy and to determine the causes of any system failures that may occur. One particularly promising method is multipoint testing combined with improved failure-analysis techniques. Variants of this method include ASTM Method D2837, the

De Blieu

2009-01-01

465

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

466

Structural Plasticity Can Produce Metaplasticity  

Microsoft Academic Search

BackgroundSynaptic plasticity underlies many aspect of learning memory and development. The properties of synaptic plasticity can change as a function of previous plasticity and previous activation of synapses, a phenomenon called metaplasticity. Synaptic plasticity not only changes the functional connectivity between neurons but in some cases produces a structural change in synaptic spines; a change thought to form a basis

Georgios Kalantzis; Harel Z. Shouval; Matthieu Louis

2009-01-01

467

Shear Wave Generation from Confined Explosions  

NASA Astrophysics Data System (ADS)

Although the ratio of S- to P-waves is believed to be the best criterion to discriminate underground explosions from earthquakes, the mechanism of S-wave generation from confined explosions is still poorly understood. In order to measure P- and S-waves generated from confined explosions in ~1 meter size rock samples, a method is developed based on the different characteristics of incident P- and S-wave reflections from free-surfaces of rocks and the properties of strain gauges. The relationship between particle displacements of incident P- and S-waves and strains measured by strain gauges are decided and given analytically. From the tamped and decoupled experiments conducted on Bedford limestone, P- and SV-waves were clearly recorded. Initial experimental results show that tamped explosions are more efficient for SV-wave generations than decoupled explosions. The P- and S-wave decay with distance from the center of explosions also is given.

Liu, C.

1997-07-01

468

Plane Shock Generator Explosive Lens: PH 13-8 Mo stainless steel versus 4340 steel shock wave separators and LX-13 versus PBX-9501 explosive particle velocity-time profiles  

SciTech Connect

Sandia National Laboratories is currently involved in the optimization of a Plane Shock Generator Explosive Lens (PSGEL). This PSGEL component is designed to generate a planar shock wave transmitted to perform a function through a steel bulkhead without rupturing or destroying the integrity of the bulkhead. The PSGEL component consists of a detonator, explosive, brass cone and tamper housing. The purpose of the PSGEL component is to generate a plane shock wave input to 4340 steel bulkhead (wave separator) with a ferro-electric (PZT) ceramic disk attached to the steel on the surface opposite the PSGEL. The planar shock wave depolarizes the PZT 65/35 ferroelectric ceramic to produce an electrical output. Elastic, plastic I and plastic II waves with different velocities are generated in the steel bulkhead. The depolarization of the PZT ceramic is produced by the elastic wave of specific amplitude (10--20 Kilobars) and this process must be completed before (about 0. 15 microseconds) the first plastic wave arrives at the PZT ceramic. Measured particle velocity versus time profiles, using a Velocity Interferometer System for Any Reflector (VISAR) are presented for the brass and steel output free surfaces. Peak pressures are calculated from the particle velocities for the elastic, plastic I and plastic 11 waves in the steel. The work presented here investigates replacing the current 4340 steel with PH 13-8 Mo stainless steel in order to have a more corrosion resistant, weldable and more compatible material for the multi-year life of the component. Therefore, the particle velocity versus time profile data are presented comparing the 4340 steel and PH 13-8 Mo stainless steel. Additionally, in order to reduce the amount of explosive, data are presented to show that LX-13 can replace PBX-9501 explosive to produce more desirable results.

Vigil, M.G.

1993-02-01

469

Explosive forming of aluminum-lithium alloys  

Microsoft Academic Search

The study suggests the use of explosive forming to form large, near-net-shape components for HLLV propellant tanks and structures in meeting this need. In combination with high-strength-to-weight aluminum-lithium alloys, explosive forming is argued to offer a significant potential cost-saving solution to the affordability issue. The principal mechanics of explosive metal-working technology, issues associated with Al-Li alloys, manufacturing considerations, potential applications

Al Doherty; Bao Nguyen

1992-01-01

470

Bioremediation of soils contaminated with explosives  

Microsoft Academic Search

The large-scale industrial production and processing of munitions such as 2,4,6-trinitrotoluene (TNT) over the past 100 years led to the disposal of wastes containing explosives and nitrated organic by-products into the environment. In the US, the Army alone has estimated that over 1.2 million tons of soil have been contaminated with explosives, and the impact of explosives contamination in other

Thomas A Lewis; David A Newcombe; Ronald L Crawford

2004-01-01

471

Explosion properties of highly concentrated ozone gas  

Microsoft Academic Search

The explosive self-decomposition characteristics of gaseous ozone with a concentration of up to almost 100vol% were quantitatively investigated using a closed system with an electric spark device. The lower self-decomposition (explosion) limit for ozone diluted with oxygen at room temperature and atmospheric pressure was 1011vol%, and so ozone at more than 1011vol% will lead to an explosive chain decomposition reaction

Kunihiko Koike; Masaharu Nifuku; Koichi Izumi; Sadaki Nakamura; Shuzo Fujiwara; Sadashige Horiguchi

2005-01-01

472

Atmospheric Pressure Wave from an Explosion  

Microsoft Academic Search

PRESSURE waves were obtained from one of two explosions set off at White Sands Missile Range (33 27' 1ST., 106 34' W.; elevation 4,900 ft. above mean sea-level), New Mexico. The first explosion occurred at 1100 p.m. M.S.T., October 28, 1965, and the second at 1100 a.m. M.S.T., November 2, 1965. These explosions were identical shots of 10 tons of

Bhartendu; R. McCrory

1966-01-01

473

Possibilities of Liquid Explosives Countermeasures at Airports  

Microsoft Academic Search

In this article the possibilities of liquid explosives revelation during routine checking of person and baggage are discussed.\\u000a Both the containers filled with liquid explosives and assembled IEDs can be detected easily. There are a few possibilities\\u000a to distinguish the kind of liquid by common x-ray system at checkpoints. Apart from some particle detectors the explosive\\u000a and flammable liquids can

J. Turecek

474

Explosive Vapour Detection Using Micromechanical Sensors  

Microsoft Academic Search

MEMS-based microcantilever platforms have been used to develop extremely sensitive explosive vapour sensors. Two unique approaches\\u000a of detecting of explosive vapours are demonstrated. In the first approach a cantilever beam coated with a selective layer\\u000a undergoes bending and resonance frequency variation due to explosive vapour adsorption. The resonance frequency variation\\u000a is due to mass loading while adsorption-induced cantilever bending is

Thomas Thundat; Lal Pinnaduwage; Richard Lareau

475

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

NASA Astrophysics Data System (ADS)

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

Taylor, Steven R.; Denny, Marvin D.

1991-04-01

476

Thermal initiation of high explosives by electron beam heating  

Microsoft Academic Search

A 40-MeV electron beam has been used to uniformly heat confined samples of high explosives until explosion occurs. From observations of temperature vs time, values were obtained for the thermal initiation thresholds (deposited energy per gram until explosion) and explosion temperatures. These are good indicators of thermal explosion sensitivity. In many cases, the specific heat or the latent heat of

A. Stolovy; A. I. Namenson; J. B. Aviles Jr; E. C. Jones Jr; J. M. Kidd

1987-01-01

477

Explosive percolation transitions in Euclidean space  

NASA Astrophysics Data System (ADS)

Since the explosive percolation transition was discovered in a random graph model in the Achlioptas process, whether the explosive percolation transition is indeed discontinuous or continuous has been controversial. Even though extensive studies have been focused on the mean-field behavior of the type of the explosive percolation transition, only a few studies are carried out in Euclidean space, Here, we show that depending on a parameter we introduce, the explosive percolation transition can be either discontinuous or continuous transition in Euclidean space, and is reduced to be continuous in the mean-field limit, which can be shown using an analytic approach.

Sul Cho, Young; Hwang, Sungmin; Jrgen Herrmann, Hans; Kahng, Byungnam

2013-03-01

478

Shock Initiation of Damaged Explosives  

SciTech Connect

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

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

2009-10-22

479

Fragmentation of explosively driven Al-W granular composite rings  

NASA Astrophysics Data System (ADS)

Al oxidation has a chemical potential nearly 5 times that of traditional high explosives, however, the oxidation rate scales with the Al particle size. To oxidize on a time scale of 1ms, Al particle size needs to be on the order of 20microns. Continuum theory and experiments of homogeneous materials show that fragments generated under typical loading conditions have much larger sizes (order 1-10mm). Using a highly heterogeneous material with constituents that have drastically different shock impedances (such as Al and W) provides additional mesoscale mechanisms that allow for further pulverization of the material into smaller fragments. Explosively driven expanding ring experiments were conducted on Al-W granular composite rings and recovered fragments showed a significant reduction in the fragment size compared to a homogeneous sample. Examination of the fragments under SEM showed a propensity for fragments to be composed of a cluster of Al and W particles with little plastic deformation in the interior Al. Hydrocode simulations were conducted to gain an insight into this clustering behavior. Understanding of the mesoscale mechanisms may be used to generate mesostructures that could tailor the size of generated fragments based on the loading conditions.

Olney, Karl; Chiu, Po-Hsun; Braithwaite, Chris; Jardine, Andrew; Collins, Adam; Benson, David; Nesterenko, Vitali

2013-03-01

480

Instrumentation advances in emissions characterization from propellant/explosive combustion  

SciTech Connect

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

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

1995-12-31

481

Explosive demolition of activated concrete  

NASA Astrophysics Data System (ADS)

This paper describes the removal of a radiologically contaminated concrete pad. This pad was removed during 1979 by operating personnel under the direction of the Waste Management Program of EG and G Idaho, Inc. The concrete pad was the foundation for the Organic Moderated Reactor Experiment (OMRE) reactor vessel. The pad consisted of a cylindrical concrete slab 15 ft in diameter, 2 ft thick, and reinforced with steel bar. It was poured directly onto basalt rocks approximately 20 ft below grade. The entire pad contained induced radioactivity and was therefore demolished, boxed, and buried rather than being decontaminated. The pad was demolished by explosive blasting.

Smith, D. L.

1980-04-01

482

Explosives detection using nanoporous coatings  

NASA Astrophysics Data System (ADS)

Zeolite-coated cantilevers provided with internal heating elements have been developed and used for the selective detection of nitroderivates, in particular o-nitrotoluene as an example of an explosive-related molecule. In particular, Co exchanged commercial BEA zeolites have been deployed of rectangular Si cantilevers by microdropping technique. In particular, two different strategies have been demonstrated to increase the zeolite modified cantilevers performance: the sensing coating and the operating temperature. As a result, o-nitrotoluene LOD values below 1 ppm are attained at room temperature conditions; whereas the interference of toluene at concentrations below 1000 ppm is completely suppressed by heating the cantilever.

Pina, Mara P.; Pellejero, Ismael; Urbiztondo, Miguel; Ses, Javier; Santamara, J.

2011-05-01

483

Big Explosions and Strong Gravity  

NSDL National Science Digital Library

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

2011-01-01

484

Supernova Explosions Stay In Shape  

NASA Astrophysics Data System (ADS)

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

2009-12-01

485

Metal objects mapping after small charge explosions. A study on AISI 304Cu steel with two different grain sizes.  

PubMed

Evidence of exposure of a metal component to a small charge explosion can be detected by observing microstructural modifications; they may be present even if the piece does not show noticeable overall plastic deformations. Particularly, if an austenitic stainless steel (or another metal having a face-centered cubic structure and a low stacking fault energy) is exposed to an explosive shock wave, high-speed deformation induces primarily mechanical twinning, whereas, in nonexplosive events, a lower velocity plastic deformation first induces slip. The occurrence of mechanical twins can be detected even if the surface is damaged or oxidized in successive events. In the present research, optical metallography (OM) and scanning electron microscopy (SEM), and scanning tunneling microscopy (STM) were used to detect microstructural modifications caused on AISI 304Cu steel disks by small-charge explosions. Spherical charges of 54.5 or 109 g TNT equivalent mass were used at explosive-to-target distances from 6.5 to 81.5 cm, achieving peak pressures from 160 to 0.5 MPa. Explosions induced limited or no macro-deformation. Two alloy grain sizes were tested. Surface OM and SEM evidenced partial surface melting, zones with recrystallization phenomena, and intense mechanical twinning, which was also detected by STM and X-ray diffraction. In the samples' interior, only twins were seen, up to some distance from the explosion impinged surface and again, at the shortest charge-to-sample distances, in a thin layer around the reflecting surface. For forensic science locating purposes after explosions, the maximum charge-to-target distance at which the phenomena disappear was singled out for each charge or grain size and related to the critical resolved shear stress for twinning. PMID:16696699

Firrao, Donato; Matteis, Paolo; Scavino, Giorgio; Ubertalli, Graziano; Ienco, Maria G; Pellati, Gabriella; Piccardo, Paolo; Pinasco, Maria R; Stagno, Enrica; Costanza, Girolamo; Montanari, Roberto; Tata, Maria E; Brandimarte, Giovanni; Petralia, Santo

2006-05-01

486

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 an