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1

Plastic explosives Mike Hopkins  

E-print Network

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

Ravenel, Douglas

2

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

3

27 CFR 555.181 - Reporting of plastic explosives.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Reporting of plastic explosives. 555.181 Section 555.181 Alcohol...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Marking of...

2013-04-01

4

27 CFR 555.181 - Reporting of plastic explosives.  

...2014-04-01 false Reporting of plastic explosives. 555.181 Section 555.181 Alcohol...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Marking of...

2014-04-01

5

27 CFR 555.181 - Reporting of plastic explosives.  

Code of Federal Regulations, 2011 CFR

...2010-04-01 true Reporting of plastic explosives. 555.181 Section 555.181 Alcohol...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Marking of...

2011-04-01

6

27 CFR 555.181 - Reporting of plastic explosives.  

Code of Federal Regulations, 2012 CFR

...2010-04-01 true Reporting of plastic explosives. 555.181 Section 555.181 Alcohol...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Marking of...

2012-04-01

7

27 CFR 555.181 - Reporting of plastic explosives.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Reporting of plastic explosives. 555.181 Section 555.181 Alcohol...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Marking of...

2010-04-01

8

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

9

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

10

Microstructural Characterization of Simulated Plastic-Bonded Explosives .  

E-print Network

??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… (more)

[No author

2011-01-01

11

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

12

Autonomous characterization of plastic-bonded explosives  

NASA Astrophysics Data System (ADS)

Plastic-Bonded Explosives (PBXs) are a newer generation of explosive compositions developed at Los Alamos National Laboratory (LANL). Understanding the micromechanical behavior of these materials is critical. The size of the crystal particles and porosity within the PBX influences their shock sensitivity. Current methods to characterize the prominent structural characteristics include manual examination by scientists and attempts to use commercially available image processing packages. Both methods are time consuming and tedious. LANL personnel, recognizing this as a manually intensive process, have worked with the Kansas City Plant / Kirtland Operations to develop a system which utilizes image processing and pattern recognition techniques to characterize PBX material. System hardware consists of a CCD camera, zoom lens, two-dimensional, motorized stage, and coaxial, cross-polarized light. System integration of this hardware with the custom software is at the core of the machine vision system. Fundamental processing steps involve capturing images from the PBX specimen, and extraction of void, crystal, and binder regions. For crystal extraction, a Quadtree decomposition segmentation technique is employed. Benefits of this system include: (1) reduction of the overall characterization time; (2) a process which is quantifiable and repeatable; (3) utilization of personnel for intelligent review rather than manual processing; and (4) significantly enhanced characterization accuracy.

Linder, Kim Dalton; DeRego, Paul; Gomez, Antonio; Baumgart, Chris

2006-08-01

13

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

Code of Federal Regulations, 2012 CFR

...2010-04-01 true Importation of plastic explosives on or after April 24, 1997. 555.183...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Marking of...

2012-04-01

14

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. 555.183...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Marking of...

2011-04-01

15

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. 555.183...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Marking of...

2010-04-01

16

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. 555.183...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Marking of...

2013-04-01

17

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

...2014-04-01 false Importation of plastic explosives on or after April 24, 1997. 555.183...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Marking of...

2014-04-01

18

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

19

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

20

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

SciTech Connect

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

Hoffman, D. M., LLNL

1998-04-23

21

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

22

On the Unreacted Hugoniots of Three Plastic Bonded Explosives  

NASA Astrophysics Data System (ADS)

There is a continuing interest in determining the detonation characteristics of loaded plastic-bonded explosives (PBXs). The UK licensing agency for explosives, DOSG, wishes to better understand the response of insensitive high explosives. This has required more detailed investigation of the transit of reaction from the unreacted state to products. The starting condition, before application of a kinetic scheme to describe reaction, is thus the unreacted Hugoniot for the material. In this work three PBXs, manufactured by BAE Land Systems, are investigated and modelled. All contain RDX in differing quantities in an HTPB binder. One of them contains aluminium. Two of the materials have the same weight percentage of filler and binder but differ in the grain size distribution entrained. The experimental Hugoniots are presented, and a composite equation of state is derived using an engineering model and shown to describe the measurements well. Further applications of the technique are described and future uses are outlined.

Milne, A. M.; Bourne, N. K.; Millett, J. C. F.

2006-07-01

23

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

24

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

Microsoft Academic Search

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

Pengwan Chen; Fenglei Huang; Kaida Dai; Yansheng Ding

2005-01-01

25

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

26

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 120°C 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

27

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; Josée Brisson

2011-01-01

28

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

29

Constructing unmarked gene deletions in Legionella pneumophila.  

PubMed

The ability to construct recombinant alleles efficiently in strains of interest, particularly unmarked deletions that reduce the potential for polar effects, is essential to studies of both pathogenesis and basic bacterial physiology. Here we describe a three-phase approach for generating unmarked deletions in Legionella pneumophila by constructing a mutant allele in E. coli using ?-Red recombination, so-called recombineering; transferring the allele onto the L. pneumophila chromosome by natural transformation; and then removing the selectable marker by utilizing the Flp site-specific recombinase. This strategy can decrease the amount of clone screening required while also increasing the percentage of the time the desired allele is obtained on the first attempt. The approach is particularly suited for constructing multiple unmarked deletions in a single strain in fewer steps than traditional methods. PMID:23150396

Bryan, Andrew; Abbott, Zachary D; Swanson, Michele S

2013-01-01

30

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

ERIC Educational Resources Information Center

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

Thalji, Abdel-Majid I.

1986-01-01

31

Thermal properties and shelf life of HMX–HTPB 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

32

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

Microsoft Academic Search

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

Steven Todd; Terry Caipen; Dennis Grady; Mark Anderson

2009-01-01

33

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

Microsoft Academic Search

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

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

2009-01-01

34

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

35

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

36

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

37

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

38

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

39

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

40

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

41

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

42

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

43

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

44

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

SciTech Connect

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

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

1994-12-01

45

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

46

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

47

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

48

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

49

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

50

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

51

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.

2012-06-01

52

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

2009-05-30

53

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

54

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

55

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

NASA Astrophysics Data System (ADS)

Ni-Al laminates have shown promise as reactive materials due to their high energy release through intermetallic reaction. In addition to the traditional ignition methods, the reaction may be initiated in hot spots that can be created during mechanical loading. The explosively driven thick walled cylinder (TWC) technique was performed on two Ni-Al laminates composed of thin foil layers with different mesostructues: concentric and corrugated. These experiments were conducted to examine how these materials accommodate large plastic strain under high strain rates. Finite element simulations of these specimens with mesostuctures digitized from the experimental samples were conducted to provide insight into the mesoscale mechanisms of plastic flow. The dependence of dynamic behaviour on mesostructure may be used to tailor the hot spot formation and therefore the reactivity of the material system.

Olney, K. L.; Chiu, P. H.; Higgins, A.; Serge, M.; Weihs, T. P.; Fritz, G.; Stover, A.; Benson, D. J.; Nesterenko, V. F.

2014-05-01

56

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

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Review of unmarked documents with potential restricted data or formerly restricted data. 1045.45...Restricted Data § 1045.45 Review of unmarked documents with potential restricted data or formerly restricted data....

2010-01-01

57

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

Code of Federal Regulations, 2011 CFR

...2011-01-01 false Review of unmarked documents with potential restricted data or formerly restricted data. 1045.45...Restricted Data § 1045.45 Review of unmarked documents with potential restricted data or formerly restricted data....

2011-01-01

58

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

59

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

60

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 135°C at a rotational speed of 0.0025 rad\\/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

61

Preliminary development and characterization of a TATB\\/HMX plastic-bonded explosive  

Microsoft Academic Search

Three new explosives were devised, prepared, and partially characterized in an attempt to find a favorable compromise between the extreme safety but modest detonation performance of TATB and the modest safety but excellent detonation performance of HMX. The three new formulations were all TATB\\/HMX\\/Binder - 45\\/48.5\\/6.5 vol % with Viton A and Kraton-1650 used as binders, and with two granulations

H. C. Hornig; R. R. McGuire

1980-01-01

62

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

63

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

64

Modeling structured population dynamics using data from unmarked individuals.  

PubMed

The study of population dynamics requires unbiased, precise estimates of abundance and vital rates that account for the demographic structure inherent in all wildlife and plant populations. Traditionally, these estimates have only been available through approaches that rely on intensive mark-recapture data. We extended recently developed N-mixture models to demonstrate how demographic parameters and abundance can be estimated for structured populations using only stage-structured count data. Our modeling framework can be used to make reliable inferences on abundance as well as recruitment, immigration, stage-specific survival, and detection rates during sampling. We present a range of simulations to illustrate the data requirements, including the number of years and locations necessary for accurate and precise parameter estimates. We apply our modeling framework to a population of northern dusky salamanders (Desmognathus fuscus) in the mid-Atlantic region (USA) and find that the population is unexpectedly declining. Our approach represents a valuable advance in the estimation of population dynamics using multistate data from unmarked individuals and should additionally be useful in the development of integrated models that combine data from intensive (e.g., mark-recapture) and extensive (e.g., counts) data sources. PMID:24649642

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

2014-01-01

65

Plasticity  

Microsoft Academic Search

Summary  Over 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

66

Non-Native Language as the Unmarked Code in Bilingual Utterances of Libyan Children in USA  

ERIC Educational Resources Information Center

This paper investigates the effect of multiple cultures and languages on the bilingual utterances of Libyan children who live in the United States and who have acquired English after they arrived there at ages from 3 to 5. Data analysis is based on the Markedness Model (Myers-Scotton, 1993) in order to determine which language is the unmarked code…

Abugharsa, Azza

2013-01-01

67

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

PubMed

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

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

2014-04-01

68

Extrusion cast explosive  

DOEpatents

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

Scribner, K.J.

1985-01-29

69

Extrusion cast explosive  

DOEpatents

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

Scribner, K.J.

1985-11-26

70

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

...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...

2014-01-01

71

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

2006-10-11

72

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

USGS Publications Warehouse

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

Fiske, Ian J.; Chandler, Richard B.

2011-01-01

73

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

USGS Publications Warehouse

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

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

2011-01-01

74

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

75

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

PubMed

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

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

2014-07-01

76

Use of a ura5+-lys7+ cassette to construct unmarked gene knock-ins in Schizosaccharomyces pombe.  

PubMed

While the counterselectable Schizosaccharomyces pombe ura4(+) gene can be used to prepare a site in the S. pombe genome to receive an unmarked mutant allele (loss of ura4(+) confers 5FOA-resistant (5FOA(R)) growth), the desired unmarked knock-in strains are generally outnumbered by spontaneously arising 5FOA(R) mutants. Relative to the same approach using the homologous URA3(+) gene in Saccharomyces cerevisiae, knock-ins in S. pombe are harder to identify due to a lower efficiency of homologous recombination and a relatively high background of spontaneous 5FOA(R) colonies. To develop an improved method for identifying cells receiving unmarked mutant alleles, we first determined that 5FOA(R) strains carry mutations in either of two genes; ura4(+) and ura5(+). We then cloned the S. pombe ura5(+) orotate phosphoribosyltransferase gene and constructed a 2.1 kb cassette containing ura5(+) together with the S. pombe lys7(+) gene. Using this doubly marked cassette to disrupt the sck1(+) kinase gene, we can distinguish between strains created by homologous knock-in of unmarked wild-type or kinase-dead alleles and spontaneously arising ura4(-) and ura5(-) mutants by screening 5FOA(R) colonies for the loss of the lys7(+) marker. The utility of this system, especially when the phenotype for the strain carrying the knock-in allele is indistinguishable from that of the disruption strain, is borne out by the fact that ~95% of 5FOA(R) colonies in our studies arose from background ura4(-) and ura5(-) mutations. PMID:22198627

Mudge, Dayna K; Hoffman, Catherine A; Lubinski, Tristan J; Hoffman, Charles S

2012-02-01

77

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

78

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

PubMed

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

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

2014-01-01

79

Insensitive explosive  

SciTech Connect

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

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

1991-12-31

80

sacB-5-Fluoroorotic acid-pyrE-based bidirectional selection for integration of unmarked alleles into the chromosome of Rhodobacter capsulatus.  

PubMed

The gram-negative, purple nonsulfur, facultative photosynthetic bacterium Rhodobacter capsulatus is a widely used model organism and has well-developed molecular genetics. In particular, interposon mutagenesis using selectable gene cartridges is frequently employed for construction of a variety of chromosomal knockout mutants. However, as the gene cartridges are often derived from antibiotic resistance-conferring genes, their numbers are limited, which restricts the construction of multiple knockout mutants. In this report, sacB-5-fluoroorotic acid (5FOA)--pyrE-based bidirectional selection that facilitates construction of unmarked chromosomal knockout mutations is described. The R. capsulatus pyrE gene encoding orotate phosphoribosyl transferase, a key enzyme of the de novo pyrimidine nucleotide biosynthesis pathway, was used as an interposon in a genetic background that is auxotrophic for uracil (Ura-) and hence resistant to 5FOA (5FOA(r)). Although Ura+ selection readily yielded chromosomal allele replacements via homologous recombination, selection for 5FOA(r) to replace pyrE with unmarked alleles was inefficient. To improve the latter step, 5FOA(r) selection was combined with sucrose tolerance selection using a suicide plasmid carrying the Bacillus subtilis sacB gene encoding levansucrase that induces lethality upon exposure to 5% (wt/vol) sucrose in the growth medium. Sucrose-tolerant, 5FOA(r) colonies that were obtained carried chromosomal unmarked mutant alleles of the target gene via double crossovers between the resident pyrE-marked and incoming unmarked alleles. The effectiveness of this double selection was proven by seeking insertion and deletion alleles of helC involved in R. capsulatus cytochrome c biogenesis, which illustrated the usefulness of this system as a genetic means for facile construction of R. capsulatus unmarked chromosomal mutants. PMID:15932997

Yano, Takahiro; Sanders, Carsten; Catalano, John; Daldal, Fevzi

2005-06-01

81

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

PubMed

Pregnant goats were employed to assess unmarked deletion mutant vaccine candidates BMDeltaasp24, BMDeltacydBA, and BMDeltavirB2, as the target host species naturally infected with Brucella melitensis. Goats were assessed for the degree of pathology associated with the vaccine strains as well as the protective immunity afforded by each strain against abortion and infection after challenge with wild-type Brucella melitensis 16M. Both BMDeltaasp24 and BMDeltavirB2 were considered safe vaccine candidates in the pregnant goat model because they did not cause abortion or colonize fetal tissues. BMDeltaasp24 was isolated from the maternal tissues only, indicating a slower rate of clearance of the vaccine strain than for BMDeltavirB2, which was not isolated from any maternal or fetal tissues. Both strains were protective against abortion and against infection in the majority of pregnant goats, although BMDeltaasp24 was more efficacious than BMDeltavirB2 against challenge infection. PMID:16697090

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

2006-06-12

82

An Orientation to Explosive Safety.  

ERIC Educational Resources Information Center

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

Harris, Betty W.

1987-01-01

83

Shock Hugoniot Relation of Unreacted Heterogeneous Explosives  

NASA Astrophysics Data System (ADS)

There is a continuing interest in determining the characteristics of unreacted plastic bonded explosives (PBXs). In this work, a Particle Velocity Comparing Method to determine the unreacted Hugoniot of heterogeneous explosive using magnetic particle velocity gauge is described. The Hugoniot for the PBXs has been measured using flyer driven by planar wave lens. A superposition principle considering unreacted explosives as composite and porous materials is presented, the unreacted Hugoniot of explosives is calculated, and the results of calculation are compared with the experiment results.

Fu, Hua; Li, Tao; Tan, Duo-Wang; Zhao, Feng

84

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

PubMed Central

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

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

2014-01-01

85

"Explosive" Physics.  

ERIC Educational Resources Information Center

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

Kienzynski, Mark J.

1998-01-01

86

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

87

Nanoengineered explosives  

DOEpatents

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

Makowiecki, Daniel M. (Livermore, CA)

1996-01-01

88

Geophysical Survey of an Abandoned Cemetery in Prairie View, Texas: Unmarked Burials from Slave Era Discovered on College Campus  

NASA Astrophysics Data System (ADS)

Wyatt Chapel Cemetery is an abandoned cemetery located in Prairie View, Texas. Oral histories from local residents suggest that the cemetery originated as a slave burial ground in the mid-nineteenth century. The local community is interested in examining the cemetery in order to document the history of the area. Over the past three years, we have acquired total station, global positioning system (GPS) and ground-penetrating radar (GPR) data at the cemetery. We utilized a GSSI cart-mounted 400 MHz radar system to image the subsurface. The soil at the field site is ideally suited for radar work and the subsurface image quality is excellent. The dielectric constant was determined to be 17 based upon the depth to a known target. Records were 80 ns in length, which corresponds to a depth of about 105 inches (8.75 feet). Data were processed to time zero and stacked. The stratigraphy consists of 3-6 feet of sand overlying a hard clay, and the boundary produces a very bright reflector. This stratigraphy is interpreted as fluvial Pleistocene sands overlying Tertiary clay. Samples were taken at multiple depths down to this boundary and radiocarbon dates are pending. Numerous anomalies were identified that are consistent with unmarked burials. Two of these anomalies were excavated and confirmed as burials. In the main clearing of the cemetery site, the sand-clay boundary deepens abruptly from 3 feet to approximately 5 feet. This anomaly was initially considered a possible man-made excavation, perhaps a mass burial site. While the stratigraphy does contain abrupt terminations, most depth changes occur gradually, suggesting formation by natural processes. Aerial photographs from 1930 indicate three adjacent creek paths west of the site, originally thought to be abandoned meanders. However, GPS data indicate the outer meander is the active creek bed, suggesting that the other paths were created during isolated flood events. Severe flood events could have caused significant erosion of the sand layer in this area.

Henning, A. T.; Sawyer, D. S.; Wallace, D.; Kahera, A.

2009-12-01

89

Population Explosion  

NSDL National Science Digital Library

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

Program, The W.

90

Explosive complexes  

DOEpatents

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

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

2011-08-16

91

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

92

Terahertz spectroscopy techniques for explosives detection  

Microsoft Academic Search

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

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

2009-01-01

93

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

94

Explosive Joining  

NASA Technical Reports Server (NTRS)

Laurence J. Bement of Langley Research Center invented a technique to permit metal joining operations under hazardous or inaccessible conditions. The process, which provides a joint with double the strength of the parent metal, involves the use of very small quantities of ribbon explosive to create hermetically sealed joints. When the metal plates are slammed together by the explosion's force, joining is accomplished. The collision causes a skin deep melt and ejection of oxide films on the surfaces, allowing a linkup of electrons that produce superstrong, uniform joints. The technique can be used to join metals that otherwise would not join and offers advantages over mechanical fasteners and adhesives. With Langley assistance, Demex International Ltd. refined and commercialized the technology. Applications include plugging leaking tubes in feedwater heaters. Demex produces the small plugs, associated sleeves and detonators. The technology allows faster plugging, reduces downtime, cuts plugging costs and increases reliability.

1989-01-01

95

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

Federal Register 2010, 2011, 2012, 2013

...nitroisobutametriol trinitrate]. Nitrate explosive mixtures. Nitrate sensitized with gelled nitroparaffin. Nitrated carbohydrate explosive. Nitrated glucoside explosive. Nitrated polyhydric alcohol explosives. Nitric acid and a nitro aromatic...

2013-10-28

96

Ignition of a confined high explosive under low velocity impact  

Microsoft Academic Search

In the framework of low velocity impact studies, dedicated to safety analyses of plastic bonded explosives (PBX), we propose a new numerical tool, designed for restituting the ignition of a HMX (high melting point explosive) based composition. Major results are the use of a concrete-like constitutive law for the PBX and an efficient implementation of an ignition criterion. We also

C. Gruau; D. Picart; R. Belmas; E. Bouton; F. Delmaire-Sizes; J. Sabatier; H. Trumel

2009-01-01

97

DETONATION PROPERTIES OF EXPLOSIVES CONTAINING NANOMETRIC ALUMINUM POWDER  

Microsoft Academic Search

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

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

98

Analysis of Explosives  

Microsoft Academic Search

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

Jehuda Yinon; John C. Hoffsommer

1977-01-01

99

Universe Explosions  

E-print Network

A scenario for a quantum big crunch to big bang transition is proposed. We first clarify the similarities between this transition and the final stages of black hole evaporation. The black hole and the universe are thought of as quantum states. The importance of an external observer for understanding the big crunch to big bang transition is emphasized. Then, relying on the similarities between the black hole and the universe, we propose that the transition should be described as an explosion that connects the contracting phase to the expanding one. The explosion occurs when entropy bounds are saturated, or equivalently when the states cease to be semiclassically (meta)stable. We discuss our scenario in three examples: collapsing dust, a brane universe falling into a bulk black hole in anti-de Sitter space, and a contracting universe filled with a negative cosmological constant and a small amount of matter. We briefly discuss the late time observables that may carry some information about the state of the universe before the transition.

Ram Brustein; Maximilian Schmidt-Sommerfeld

2012-09-24

100

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

101

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

102

Initiative for Explosives Detection  

E-print Network

Initiative for Explosives Detection Highly Concealed Bulk Explosives Detection This focus area emphasizes the detection of explosives or IEDs hidden in vehicles, buildings or various types of containers of highly concealed explosives include the development of enhanced energy sources, improved electronics

103

Optically detonated explosive device  

NASA Technical Reports Server (NTRS)

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

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

1974-01-01

104

Chromospheric explosions  

NASA Technical Reports Server (NTRS)

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

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

1986-01-01

105

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

106

Ammonium nitrate explosive systems  

SciTech Connect

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.

Coburn, M.D.; Stinecipher, M.M.

1981-11-17

107

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

108

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

109

Totally confined explosive welding  

NASA Technical Reports Server (NTRS)

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

Bement, L. J. (inventor)

1978-01-01

110

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

111

Terahertz reflection spectroscopy for the detection of explosives  

NASA Astrophysics Data System (ADS)

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

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

2008-02-01

112

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 -10°C and 25°C. The percentage of Hytemp in the samples varied from 1% (weight percent) to 2% (weight percent). Failure occurs when the shear or tensile strength of the explosive is exceeded. The fracture acceleration of pressed plastic-bonded TNAZ/Hytemp decreases with increasing percentage of Hytemp in the explosive at -10°C and 25°C. The fracture acceleration of pressed plastic-bonded 98%/2% (weight percent) TNAZ/Hytemp at 25°C is about 1/3 that at -10°C.

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

2006-07-01

113

An explosive shock tube  

Microsoft Academic Search

Experiments with a model explosive shock tube are described. Flow of a ; dense air plasma with speed 25-l0 km\\/sec is obtained by means of an explosive gas ; compressor. Photographs of flow over models were taken when the flow behind the ; shock wave becomes opaque. The experiments were conducted in a laboratory ; explosion chamber, (auth);

A. E. Voitenko; M. A. Lyubimova; E. P. Matochkin

1973-01-01

114

High-nitrogen explosives  

Microsoft Academic Search

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.

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

2002-01-01

115

Explosives with Lined Cavities  

Microsoft Academic Search

Explosives detonated in contact with thick steel plates produce much deeper holes in the steel when there is a cavity in the explosive in contact with the plate. While this phenomenon has been known for more than 150 years, the enormous increase in penetrating power that can be produced by lining the explosive cavity with thin metal has been discovered

Garrett Birkhoff; Duncan P. MacDougall; Emerson M. Pugh; Geoffrey Taylor

1948-01-01

116

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

117

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

118

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

119

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

120

Explosives Development and Fundamentals of Explosives Technology  

Microsoft Academic Search

\\u000a This introductory chapter is intended to give a brief outline of the history of the development of some common explosives\\u000a and point the reader toward more weighty texts where full details of each of the points made and many more may be found. It\\u000a also seeks to provide an introduction to some of the fundamentals of explosives technology, acting as

Peter R. Lee

121

New Mix Explosives for Explosive Welding  

NASA Astrophysics Data System (ADS)

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

Andreevskikh, Leonid

2011-06-01

122

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

PubMed

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

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

2014-12-01

123

Explosive plane-wave lens  

SciTech Connect

An explosive wave lens is described comprising: a. a donor explosive; b. detonator means for generating a detonation wave in the donor explosive; c. an acceptor explosive; d. impactor means for receiving the detonation wave and for striking the acceptor explosive to produce a second detonation wave having a predetermined form in the acceptor explosive; and e. spacer means for spacing the impactor means apart from the acceptor explosive.

Marsh, S.P.

1988-03-08

124

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.

125

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.

126

The Scaled Thermal Explosion Experiment  

Microsoft Academic Search

We have developed the Scaled Thermal Explosion Experiment (STEX) to provide a database of reaction violence from thermal explosion for explosives of interest. Such data are needed to develop, calibrate, and validate predictive capability for thermal explosions using simulation computer codes. A cylinder of explosive 25, 50 or 100 mm in diameter, is confined in a steel cylinder with heavy

J. F. Wardell; J. L. Maienschein

2002-01-01

127

Detonation in Liquid Explosives  

Microsoft Academic Search

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

D. Croney

1948-01-01

128

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

129

Idaho Explosives Detection System  

Microsoft Academic Search

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

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

2005-01-01

130

An explosion in Tunguska  

Microsoft Academic Search

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

Ioan Nistor

2008-01-01

131

Coal dust explosibility  

Microsoft Academic Search

This paper reports US Bureau of Mines (USBM) research on the explosibility of coal dusts. The purpose of this work is to improve safety in mining and other industries that process or use coal. Most of the tests were conducted in the USBM 20 litre laboratory explosibility chamber. The laboratory data show relatively good agreement with those from full-scale experimental

Kenneth L. Cashdollar

1996-01-01

132

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

133

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

134

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

135

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

PubMed Central

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

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

2014-01-01

136

Optically measured explosive impulse  

NASA Astrophysics Data System (ADS)

An experimental technique is investigated to optically measure the explosive impulse produced by laboratory-scale spherical charges detonated in air. Explosive impulse has historically been calculated from temporal pressure measurements obtained via piezoelectric transducers. The presented technique instead combines schlieren flow visualization and high-speed digital imaging to optically measure explosive impulse. Prior to an explosive event, schlieren system calibration is performed using known light-ray refractions and resulting digital image intensities. Explosive charges are detonated in the test section of a schlieren system and imaged by a high-speed digital camera in pseudo-streak mode. Spatiotemporal schlieren intensity maps are converted using an Abel deconvolution, Rankine-Hugoniot jump equations, ideal gas law, triangular temperature decay profile, and Schardin's standard photometric technique to yield spatiotemporal pressure maps. Temporal integration of individual pixel pressure profiles over the positive pressure duration of the shock wave yields the explosive impulse generated for a given radial standoff. Calculated explosive impulses are shown to exhibit good agreement between optically derived values and pencil gage pressure transducers.

Biss, Matthew M.; McNesby, Kevin L.

2014-06-01

137

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

138

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

139

FOUDRE ET ATMOSPHERES EXPLOSIVES LIGHTNING AND EXPLOSIVES ATMOSPHERES  

E-print Network

97-36 FOUDRE ET ATMOSPHERES EXPLOSIVES LIGHTNING AND EXPLOSIVES ATMOSPHERES HALAMA S., 1NERIS l'utilisation de produits sensibles pouvant provoquer facilement des incendies et des explosions. C inflammables. Les atmospheres explosives gazeuses et poussiereuses ainsi que les conditions favorisant [eur

Paris-Sud XI, Université de

140

Lithium niobate explosion monitor  

DOEpatents

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

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

1990-01-09

141

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

1990-01-01

142

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

Federal Register 2010, 2011, 2012, 2013

...nitroisobutametriol trinitrate]. Nitrate explosive mixtures. Nitrate sensitized with gelled nitroparaffin. Nitrated carbohydrate explosive. Nitrated glucoside explosive. Nitrated polyhydric alcohol explosives. Nitric acid and a nitro aromatic...

2011-10-19

143

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

Federal Register 2010, 2011, 2012, 2013

...nitroisobutametriol trinitrate]. Nitrate explosive mixtures. Nitrate sensitized with gelled nitroparaffin. Nitrated carbohydrate explosive. Nitrated glucoside explosive. Nitrated polyhydric alcohol explosives. Nitric acid and a nitro aromatic...

2012-09-20

144

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

Federal Register 2010, 2011, 2012, 2013

...nitroisobutametriol trinitrate]. Nitrate explosive mixtures. Nitrate sensitized with gelled nitroparaffin. Nitrated carbohydrate explosive. Nitrated glucoside explosive. Nitrated polyhydric alcohol explosives. Nitric acid and a nitro aromatic...

2010-11-17

145

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

Federal Register 2010, 2011, 2012, 2013

...nitroisobutametriol trinitrate]. Nitrate explosive mixtures. Nitrate sensitized with gelled nitroparaffin. Nitrated carbohydrate explosive. Nitrated glucoside explosive. Nitrated polyhydric alcohol explosives. Nitric acid and a nitro aromatic...

2010-01-08

146

Direct real-time detection of vapors from explosive compounds.  

PubMed

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

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

2013-11-19

147

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

148

Disorder induces explosive synchronization  

NASA Astrophysics Data System (ADS)

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

Skardal, Per Sebastian; Arenas, Alex

2014-06-01

149

Explosive Magnetic Generators Of \\  

Microsoft Academic Search

Among the known types of electromagnetic energy sources, the explosive magnetic generators (=G) are the best characterized in terms of their specific energy output and cost. The results of studies on \\

V. K. Chernyahev; M. S. Protasov; V. A. Shevtsov; P. N. Fiskarev; B. I. Zharinov; G. I. Volkov; V. V. Vakhrunhev; B. B. Grinevitch; A. Ivanov; V. A. Demidov; C. V. Pak; X. P. Bidylo; V. P. Pogorelov; A. A. Petrukhin; A. I. Kuzjaev; V. B. Jakubov; V. I. Shpagin

1991-01-01

150

Disorder induces explosive synchronization.  

PubMed

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

Skardal, Per Sebastian; Arenas, Alex

2014-06-01

151

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

152

Saturn's Hot Plasma Explosions  

NASA Video Gallery

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

153

Idaho Explosive Detection System  

ScienceCinema

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

Klinger, Jeff

2013-05-28

154

Idaho Explosive Detection System  

SciTech Connect

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

Klinger, Jeff

2011-01-01

155

Disorder induces explosive synchronization  

E-print Network

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

Per Sebastian Skardal; Alex Arenas

2014-04-03

156

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

157

Splashes from Underwater Explosions  

Microsoft Academic Search

The splashes from the underwater explosions of 1 and 10 1b. charges of P.E. no. 2 and Nobel's Explosive '808' at various depths have been photographed with cine-cameras. The experiments were carried out in a sheltered pond which enabled the surface phenomena to be studied in greater detail than has been done hitherto, and a number of new phenomena have

H. Kolsky; J. P. Lewis; M. T. Sampson; A. C. Shearman; C. I. Snow

1949-01-01

158

Introduction Explosions in evolution problems The explosion time Stochastic Differential Equations with explosions  

E-print Network

Introduction Explosions in evolution problems The explosion time Stochastic Differential Equations with explosions Pablo Groisman University of Buenos Aires Joint work with J. Fern´andez Bonder, UBA J.D. Rossi, UBA ERPEM, November 29th, 2006 Pablo Groisman UBA Stochastic Differential Equations with explosions

Groisman, Pablo

159

LLNL's program on multiscale modeling of polycrystal plasticity  

Microsoft Academic Search

At LLNL a multiscale modeling program based on information-passing has been established for modeling the strength properties of a body-centered-cubic metal (tantalum) ,. under conditions of extreme plastic deformation. The plastic deformation experienced by an explosively-formed shaped-charge jet is an example of �extreme deformation�. The shaped charge liner material undergoes high strain rate deformation at high hydrostatic pressure. The constitutive

T. Diaz De La Rubia; N. H. Holmes; W. E. King; D. H. Lassila; J. A. Moriarty; D. J. Nikkel

1998-01-01

160

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

161

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

162

Explosively separable casing  

DOEpatents

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

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

1985-01-01

163

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

164

Vapor explosion phenomena: Scaling considerations  

SciTech Connect

Past safety analyses considered the hazard from vapor explosions in a conservative manner where engineering judgment and conservative analyses were used to estimate the likelihood of nuclear reactor containment failure from explosion-induced missile generation [alpha-mode failure]. However, recent safety analyses may require less conservative methods to determine the hazard from vapor explosions; thus one may need to consider more detailed scaling of vapor explosion phenomena. This paper proposes particular scaling considerations for vapor explosions based on recent experimental results and that vapor explosions with prototypic reactor fuel material may be less of a hazard.

Corradini, M.L. [Univ. of Wisconsin, Madison, WI (United States)

1996-08-01

165

ELECTROMAGNETIC FIELD EFFECTS IN EXPLOSIVES  

SciTech Connect

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

Tasker, D. G.; Whitley, V. H. [MS J566, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Lee, R. J. [Lndian Head Division, Naval Surface Warfare Center, Indian Head, MD 20640 (United States)

2009-12-28

166

Mechanical modeling of the plastic bonded explosive LX17  

E-print Network

/or sliding along grain boundaries. Microcracking along the grain boundary is a phenomenon that takes place in many polycrystalline solids, causing their reliability and life to degrade. Experimental evidence has shown this to be the case in metals... (Hertzberg, 1976; Suresh, 1991; Majumdar and Newaz, 1991), argillaceous salt (Chan et al. , 1997a; Chan et al. , 1997b), and sea ice (Schapery, 1997). This microcracking is qualitatively similar when examined in the macroscale, however the mechanisms...

Clayton, Kyle Martin

2012-06-07

167

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

168

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

169

Continuous steam explosion  

SciTech Connect

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

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

1995-02-01

170

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

171

Explosive Synchronization is Discontinuous  

E-print Network

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

Vladimir Vlasov; Yong Zou; Tiago Pereira

2014-11-25

172

A real explosion: the requirement of steam explosion pretreatment.  

PubMed

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

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

2012-10-01

173

Laser initiation of explosives  

NASA Astrophysics Data System (ADS)

Through laser initiation of explosives offers many advantages like controlled threshold energy over wide range, replacement of complicated safety arming mechanisms to simple and better system, immunity to RF/EMI environment etc, but there is greater difficulty to build detonator for all purpose applications and regular field trials. The challenges are to understand the interaction of laser radiation or its induced plasma with explosives, launching and transmission of high power laser beam, coupling and focussing to desired target area. This paper looks into the details of those facts.

Singh, Manpreet; Sethi, V. S.

2002-09-01

174

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. 2 figs.

Thundat, T.G.

1999-06-29

175

Direct Real-Time Detection of Vapors from Explosive Compounds  

SciTech Connect

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

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

2013-10-03

176

Physically based simulation of explosions  

E-print Network

This thesis describes a method for using physically based techniques to model an explosion and the resulting side effects. Explosions are some of the most visually exciting phenomena known to humankind and have become nearly ubiquitous in action...

Roach, Matthew Douglas

2005-08-29

177

Morley Symposium on Concrete Plasticity and its Application. University of Cambridge 23 PLASTIC DISPROPORTIONATE COLLAPSE AT LOST CORNER COLUMNS  

E-print Network

by after-shocks and fire-fighting may be then impeded by earthquake or explosion damage to water-supply and to active fire-protection systems. The FEMA/ASCE Report on The Oklahoma City Bombing concluded that, terrorist bomb, double-span mechanism, fire, yield-line analysis, plastic analysis, bimoment, Hillerborg 1

Burgoyne, Chris

178

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

PubMed

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

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

2013-12-10

179

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

180

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

181

Managing the data explosion  

USGS Publications Warehouse

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

Hooper, Richard P.; Aulenbach, Brent T.

1993-01-01

182

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

183

Underwater electrical wire explosion  

Microsoft Academic Search

A brief review of the results obtained in recent research of underwater electrical wire explosions using microsecond and nanosecond generators is presented. It was shown that the increase in the rate of energy input into the exploding wire allows one to increase the wire temperature and amplitude of shock waves (SWs). Estimated energy deposition into Cu and Al wire material

Ya E. Krasik; A. Fedotov; D. Sheftman; S. Efimov; A. Sayapin; V. Tz Gurovich; D. Veksler; G. Bazalitski; S. Gleizer; A. Grinenko; V. I. Oreshkin

2010-01-01

184

Underwater electrical wire explosion  

NASA Astrophysics Data System (ADS)

A brief review of the results obtained in recent research of underwater electrical wire explosions using microsecond and nanosecond generators is presented. It was shown that the increase in the rate of energy input into the exploding wire allows one to increase the wire temperature and amplitude of shock waves (SWs). Estimated energy deposition into Cu and Al wire material of up to 200 eV/atom was achieved. In microsecond time scale wire explosion, a good agreement was attained between the wire resistance calculated using the equation of state (EOS) and that obtained experimentally. Conversely, in nanosecond time scale wire explosion, the wire resistance of EOS was modified in order to fit experimental data. Analysis of the emitted radiation showed that black body approximation cannot be used to characterize exploding wire radiation. It was found that <=24% of the deposited energy is transferred into the water flow's mechanical energy. Also, it was shown that converging SWs formed by the explosion of cylindrical wire arrays can be used to achieve a pressure up to 250 kbar at the axis of implosion. Hydrodynamic simulations showed that with the use of relatively moderate pulsed power generators with stored energy of several hundred kilojoules, a pressure of several megabar can be achieved at the axis of implosion.

Krasik, Ya E.; Fedotov, A.; Sheftman, D.; Efimov, S.; Sayapin, A.; Gurovich, V. Tz; Veksler, D.; Bazalitski, G.; Gleizer, S.; Grinenko, A.; Oreshkin, V. I.

2010-06-01

185

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

186

Portable Raman explosives detection  

Microsoft Academic Search

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

David S. Moore; R. Jason Scharff

2009-01-01

187

Explosive Z Pinch  

E-print Network

We propose an explanation for the recently observed powerful contained explosion in a Z pinch experiment performed at Sandia National Laboratories. Our arguments are based on the assumption that a pure SU(2) Yang-Mills theory of scale $\\sim 0.5 $MeV is responsible for the emergence of the electron and its neutrino.

Francesco Giacosa; Ralf Hofmann; Markus Schwarz

2006-04-20

188

Ecotoxicology of Explosives  

SciTech Connect

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

Efroymson, Rebecca Ann [ORNL; Giffen, Neil R [ORNL; Morrill, Valerie [U.S. Army Yuma Proving Ground; Jenkins, Thomas [U.S. Corps of Engineers, Cold Regions Research & Engineering Laboratory

2009-04-01

189

Environmental fate of explosives  

Microsoft Academic Search

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

Judith C. Pennington; James M. Brannon

2002-01-01

190

Explosions: A Conference to  

E-print Network

Winds, Bubbles, & Explosions: A Conference to Honour John Dyson. Pátzcuaro, Michoacán, México, 9 spectra for analysis com­ puted with WMBASIC code (Pauldrach, Ho#­ man, Lennon 2001), and with Hillier Physics & Astronomy, Johns Hopkins University, 3400 N.Charles Baltimore, MD21210, (bianchi

Bianchi, Luciana

191

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.

192

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

193

LSP EXPLOSIVE PACKAGES FRAGMENTATION STUDY  

E-print Network

ATM 1046 LSP EXPLOSIVE PACKAGES FRAGMENTATION STUDY Prepared by: ,11. 15. :n-~ G. B. Min Approved considerations the probability of fragments from an LSP explosive package striking the ALSEP Central Station Experiment requires that Explosive Charges be detonated on the luoar surface early in the ALSEP lunar mission

Rathbun, Julie A.

194

Crack dynamics and explosive burn via generalized coordinates  

NASA Astrophysics Data System (ADS)

The growth of cracks and their role in the formation of hot spots in explosives are addressed in a three-part discussion. First the method of generalized coordinates is used to represent crack dynamics with two ordinary differential equations for crack opening and growth. These account for both stable and unstable behavior. Second, the behavior of burning cracks is addressed by coupling those differential equations to a burn model to show that burning cracks can exhibit either mild or violently unstable behavior. Finally, in the third part, it is shown that the burning crack algorithm in combination with SCRAM (which deals with Statistical CRAck Mechanics) can account for the reactive behavior of a plastic-bonded explosive (PBX 9501) subjected to multiple shocks. SCRAM allows for representation of brittle behavior in a variety of explosives, propellants, ceramics and geological materials.

Dienes, John K.; Kershner, James D.

2000-10-01

195

Thermal history sensing inside high-explosive environments using thermoluminescent microparticles  

Microsoft Academic Search

Thermoluminescent LiF:Mg,Ti (TLD-100) microparticle sensors are demonstrated to record the thermal history of the region near a detonated high explosive. Microparticles were gamma-irradiated to fill their charge-carrier traps and then exposed to the detonation of 20 g of a plastic bonded explosive formulation containing HMX and Al particles at a test distance of approximately 22 cm from the center of

Merlin L. Mah; Philip R. Armstrong; Sangho S. Kim; Joel R. Carney; James M. Lightstone; Joseph J. Talghader

2011-01-01

196

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

PubMed

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

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

2009-01-01

197

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

198

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

199

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

200

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

NASA Astrophysics Data System (ADS)

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

Šelešovský, Jakub; Krupka, Miloslav

2007-07-01

201

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 15–20% Al content as

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

2008-01-01

202

[Explosive "Roman find"].  

PubMed

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

Stiel, Michael; Dettmeyer, Reinhard; Madea, Burkhard

2006-01-01

203

Adhesion of explosives.  

PubMed

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

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

2013-06-01

204

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.

2008-04-01

205

Plastic Surgery for Teenagers  

MedlinePLUS

... A. and Weston, J. Attitudes of adolescents about cosmetic surgery. Annals of Plastic Surgery 2003; 50:628-630. ... An investigation of changes in body image following cosmetic surgery. Plastic and Reconstructive Surgery 2002 . 109:363-371. ...

206

Facial Plastic Surgery Today  

MedlinePLUS

... is a really good idea Third Quarter 2011 Cosmetic surgery to ease bullying? Second Quarter 2011 Facial Plastic ... 2014 | AMERICAN ACADEMY OF FACIAL PLASTIC AND RECONSTRUCTIVE SURGERY (AAFPRS) | ALL RIGHTS RESERVED | SITEMAP | CONTACT | PRIVACY Follow us on

207

Plastic encapsulated parts  

SciTech Connect

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

Castillo, T.

1994-10-01

208

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

209

Plastics and Health Risks  

Microsoft Academic Search

By 2010, the worldwide annual production of plastics will surpass 300 million tons. Plastics are indispensable materials in modern society, and many products manufactured from plastics are a boon to public health (e.g., disposable syringes, intravenous bags). However, plastics also pose health risks. Of principal concern are endocrine-disrupting properties, as triggered for example by bisphenol A and di-(2-ethylhexyl) phthalate (DEHP).

Rolf U. Halden

2010-01-01

210

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.

211

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. PMID:1175556

Spaak, Albert

1975-01-01

212

Tomorrow's plastic world  

Microsoft Academic Search

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 possibilites in the home and in energy generation. These possibilities are discussed here along with how plastic can be recycled and perhaps even grown.

Averil Macdonald

2005-01-01

213

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

214

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

215

Prompt Reaction of Aluminum in Detonating Explosives  

NASA Astrophysics Data System (ADS)

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 ?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.

2006-07-01

216

Linear accelerator for explosive detection  

Microsoft Academic Search

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

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

1991-01-01

217

Introduction Explosions in evolution problems Numerical approximations Adaptive numerical scheme Stochastic Differential Equations with explosions  

E-print Network

Introduction Explosions in evolution problems Numerical approximations Adaptive numerical scheme Stochastic Differential Equations with explosions Pablo Groisman University of Buenos Aires Joint work with J Stochastic Differential Equations with explosions #12;Introduction Explosions in evolution problems Numerical

Groisman, Pablo

218

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

219

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

220

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

221

Fire and explosion hazards to flora and fauna from explosives  

Microsoft Academic Search

Deliberate or accidental initiation of explosives can produce a range of potentially damaging fire and explosion effects. Quantification of the consequences of such effects upon the surroundings, particularly on people and structures, has always been of paramount importance. Information on the effects on flora and fauna, however, is limited, with probably the weakest area lying with fragmentation of buildings and

Roy Merrifield

2000-01-01

222

New plastic joints for plastic orthoses.  

PubMed

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

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

1982-04-01

223

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

224

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

Microsoft Academic Search

The histories of recent and past magazine explosions were reviewed; present explosive storage conditions and practices were observed; and existing Federal regulations on explosive storage were examined. A recent increase in magazine explosion frequency must be attributed to a large increase in deliberate explosions; fires of various origins account for the remaining explosions of the past decade. During 1884-1926 several

J. Roth

1983-01-01

225

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

226

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

227

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

228

Plasticity in fretting contact  

NASA Astrophysics Data System (ADS)

The fretting problem of a cyclically loaded cylinder on a flat elastic-plastic 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 strains in the substrate as a function of loading and friction coefficient. Shakedown maps and cyclic plastic strain behavior maps are created to describe the relative contribution of cyclic plasticity, ratcheting and shakedown as a function of loading. Cyclic plastic strain amplitudes are presented as a function of tangential load amplitude for various levels of normal pressure and friction using extensive finite element computations. Several plasticity models are considered: elastic/perfectly-plastic, isotropic strain hardening and kinematic strain hardening. The results indicate that, while the plastic strain amplitudes decrease with increased strain hardening, the qualitative behavior is insensitive to the choice of plasticity model. The results are compared with corresponding fully elastic analyses to highlight the role of plasticity during contact deformation and to evaluate the implications of using fully elastic analyses to predict crack nucleation.

Ambrico, J. M.; Begley, M. R.

2000-11-01

229

Explosive Plane-Wave Lens.  

National Technical Information Service (NTIS)

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 aro...

S. P. Marsh

1987-01-01

230

Corona discharge initiated mine explosions  

Microsoft Academic Search

Strong circumstantial evidence suggests that lightning has initiated methane explosions in abandoned and sealed areas of underground coal mines. The Mine Safety and Health Administration (MSHA) investigated several of these occurrences within recent years. The investigated explosions occurred at significant depths, ranging from 700 ft to 1200 ft. Data from the national lightning detection network indicated a strong correlation between

H. K. Sacks; Thomas Novak

2004-01-01

231

A primer on explosives costs  

Microsoft Academic Search

There are a multitude of cost centers in the typical coal mine, and almost as many ways to calculate their individual and collective effect on the bottom line. The costs of explosives is, in some ways, very difficult to determine without consideration of drilling, loading, hauling and breaking costs. Saving a nickel in explosive costs, for example, could end up

Paddock

1987-01-01

232

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

233

Explosives Detection for Aviation Security  

Microsoft Academic Search

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

Anthony Fainberg

1992-01-01

234

The Scaled Thermal Explosion Experiment  

SciTech Connect

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

Wardell, J F; Maienschein, J L

2002-07-05

235

Recycle plastics into feedstocks  

Microsoft Academic Search

Thermal cracking of mixed-plastics wastes with a fluidized-bed reactor can be a viable and cost-effective means to meet mandatory recycling laws. Strict worldwide environmental statutes require the hydrocarbon processing industry (HPI) to develop and implement product applications and technologies that reuse post-consumer mixed-plastics waste. Recycling or reuse of plastics waste has a broad definition. Recycling entails more than mechanical regranulation

H. Kastner; W. Kaminsky

1995-01-01

236

Explosion of chaotic bubbling  

NASA Astrophysics Data System (ADS)

We have studied a saddle-node bifurcation/explosion of air bubble formation driven by a sound wave, whose amplitude is the control parameter. The bubbles are formed in a nozzle submerged in a water/glycerol solution inside a cylindrical tube, and the sound wave is tuned to the air column above the fluid. The nonlinear interaction between sound wave and the fluid oscillations, caused by the air bubbles passage through the liquid, results in a route to chaos via quasi-periodicity, with some resonant states characterized by the rational winding numbers W= fs/ fb, where fs is the sound wave frequency and fb is the bubbling rate. We also have shown that the bubble dynamics is similar to the one observed in the two-dimensional circle map.

Tufaile, A.; Reyes, M. B.; Sartorelli, J. C.

2002-05-01

237

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.] [Lawrence Livermore National Lab., CA (United States). Defense Technologies Engineering Div.

1997-07-01

238

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

239

FCS722 Plastic Surgery  

E-print Network

Paper or plastic? It’s not quite the same question as at the supermarket. Paying with plastic can be convenient compared to paper transactions of cash and checks. Many consumers carry both debit and credit cards for convenience, but not all “plastic ” is the same! Remember these differences and perform a little “plastic surgery ” to effectively manage your debt. Credit Credit can be important in case of an emergency. Credit makes it possible to use an item – like an appliance – while you are paying for it. Credit may allow you to take advantage of special bargains and sales. Buying on credit may make it easier to

unknown authors

240

Plastics and health risks.  

PubMed

By 2010, the worldwide annual production of plastics will surpass 300 million tons. Plastics are indispensable materials in modern society, and many products manufactured from plastics are a boon to public health (e.g., disposable syringes, intravenous bags). However, plastics also pose health risks. Of principal concern are endocrine-disrupting properties, as triggered for example by bisphenol A and di-(2-ethylhexyl) phthalate (DEHP). Opinions on the safety of plastics vary widely, and despite more than five decades of research, scientific consensus on product safety is still elusive. This literature review summarizes information from more than 120 peer-reviewed publications on health effects of plastics and plasticizers in lab animals and humans. It examines problematic exposures of susceptible populations and also briefly summarizes adverse environmental impacts from plastic pollution. Ongoing efforts to steer human society toward resource conservation and sustainable consumption are discussed, including the concept of the 5 Rs--i.e., reduce, reuse, recycle, rethink, restrain--for minimizing pre- and postnatal exposures to potentially harmful components of plastics. PMID:20070188

Halden, Rolf U

2010-01-01

241

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

242

Studies of plastic insulators under shock conditions  

SciTech Connect

As experiments done with explosively driven switches and magnetic flux compression generators become complex, the details become increasingly important. In most experiments the detonation of explosives is done through hyers of material that include metal and plastic, which may retard the detonation, and at the same time the insulating materials must maintain their integrity at high voltages. We have initiated some small-scale experiments that use a few hundred grams of explosives to study effects on shocked materials. These studies look at effects on detonation through various materials as a function of their thickness, and will be compared with hydrodynamic computer modeling done with the MESA2D code. Another related series of experiments observed the voltage breakdown o f insulators under shock conditions. In this set of experiments insulators made of polyethylene, Teflon and Mylar were placed between two electrodes and exposed to 12OKV during a shock. The timing of the shock was determined from light produced at a flash gap. Photo-diodes coupled to optical fibers were used to transmit the signals to the diagnostic bunker. A Pearson probe was used to monitor the voltage at the insulator during the breakdown. The timing of the breakdown relative to the shock arrival time was recorded. The breakdown data as a function of materials and geometry are provided in this report. Also, these data are compared with computer simulations that may suggest material conditions at the time of insulator failure.

Oona, H. (Henn); Goforth, J. H. (James H.); Tasker, D. G. (Douglas G.); King, J. C. (James Carrel); Sena, F. C. (Francis C.); Kiuttu, G.; Casvassos, T.

2001-01-01

243

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

244

Rigid-plastic analysis of underwater blast loaded stiffened plates  

Microsoft Academic Search

A new simplified method of analysis is developed to predict the nonlinear dynamic response of submerged stiffened plates subjected to underwater explosions. The dynamic response of the structure is modelled by using rigid-plastic beam and beam-grillage approaches developed previously for air-blast loaded stiffened plates and the fluid-structure interaction is simulated by applying the simple Hains acoustic approximations directly on the

J Jiang; M. D Olson

1995-01-01

245

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

246

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

247

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, the authors examine gaseous and aqueous products of base hydrolysis of the HMX-based plastic bonded explosive, PBX-9404. The authors 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.

1995-04-01

248

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

249

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

250

Biodegradable Plastics from Cellulose  

Microsoft Academic Search

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

Mariko Yoshioka; Nobuo Shiraishi

2000-01-01

251

Biodegradation of plastics  

Microsoft Academic Search

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

Masayuki Shimao

2001-01-01

252

Plastic Recycling Toter -ORANGE  

E-print Network

Plastic Recycling Toter - ORANGE Glass Recycling Toter - TEAL Garbage Yellow sharps container - bulk rinsing for small items - Clear Glass - Broken glass is ok - rinsed 3 times - may have contained - Plastic disposable pipettes - Micropipette tips - Petri dishes - cell well plates - racks - Glass

Toronto, University of

253

STATIC ELECTRICITY Plastic combs  

E-print Network

. You may use a variety of materials to try to "charge" the comb or balloon--paper towels, paper, blueSTATIC ELECTRICITY Materials · Plastic combs · Balloons · Thread · Scissors · Cheerios · Paper of Cheerios on a paper plate. 2. Take the plastic lid and rub it against whatever is available (hair, fleece

Benitez-Nelson, Claudia

254

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

255

Plasticity in fretting contact  

Microsoft Academic Search

The fretting problem of a cyclically loaded cylinder on a flat elastic–plastic 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

256

Plastic bag suffocation.  

PubMed

Suffocation by plastic bag is not common. The finding of a body at the scene of death with a plastic bag in situ could be diagnostically valuable to the pathologist. Otherwise the pathologist may be hard put to arrive at a firm opinion as to how the deceased met his/her death; in fact, in three of the cases reported in this paper, the local pathologist could not give a cause of death when the initial autopsy was performed. Plastic bags could be accidentally placed over the head; put there to help in the inhalation of volatile substances; with homicidal intention; or simply as an effective suicidal method. The object of this paper is to study the cases where bodies were found with a plastic bag over the head, and in particular the cases where the cause of death was due to plastic bag suffocation. PMID:8429773

Perez Martinez, A L; Chui, P; Cameron, J M

1993-01-01

257

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

258

The efficiency of an explosive plasma compressor  

Microsoft Academic Search

The paper presents results of an experimental investigation of the efficiency of an explosive plasma compressor. The experimental set-up consisted of the explosive plasma compressor and a calorimeter. The detonation of an explosive charge produced a shock wave which compressed the working gas and converted it into a plasma. The plasma was thrust by the explosion into a steel calorimetric

A. E. Voitenko; V. I. Kirko

1975-01-01

259

Prompt detonation of secondary explosives by laser  

Microsoft Academic Search

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

Paisley

1989-01-01

260

Explosives detection with hard-wired moths  

Microsoft Academic Search

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

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

2004-01-01

261

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

PubMed

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

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

2014-09-01

262

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

263

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

264

JiTT - Cambrian Explosion  

NSDL National Science Digital Library

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

Guertin, Laura

265

Explosive plane-wave lens  

DOEpatents

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

Marsh, S.P.

1987-03-12

266

Explosive plane-wave lens  

DOEpatents

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

Marsh, S.P.

1988-03-08

267

Explosive Spot Joining of Metals  

NASA Technical Reports Server (NTRS)

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

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

1997-01-01

268

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

269

The characterization and evaluation of accidental explosions  

NASA Technical Reports Server (NTRS)

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

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

1975-01-01

270

Quantitative understanding of explosive stimulus transfer  

NASA Technical Reports Server (NTRS)

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

Schimmel, M. L.

1973-01-01

271

Disaster management following explosion.  

PubMed

Explosions and bombings remain the most common deliberate cause of disasters involving large numbers of casualties, especially as instruments of terrorism. These attacks are virtually always directed against the untrained and unsuspecting civilian population. Unlike the military, civilians are poorly equipped or prepared to handle the severe emotional, logistical, and medical burdens of a sudden large casualty load, and thus are completely vulnerable to terrorist aims. To address the problem to the maximum benefit of mass disaster victims, we must develop collective forethought and a broad-based consensus on triage and these decisions must reach beyond the hospital emergency department. It needs to be realized that physicians should never be placed in a position of individually deciding to deny treatment to patients without the guidance of a policy or protocol. Emergency physicians, however, may easily find themselves in a situation in which the demand for resources clearly exceeds supply and for this reason, emergency care providers, personnel, hospital administrators, religious leaders, and medical ethics committees need to engage in bioethical decision-making. PMID:18522253

Sharma, B R

2008-01-01

272

Steam explosion research at Sandia  

SciTech Connect

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

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

1980-01-01

273

Interplay of explosive thermal reaction dynamics and structural confinement  

NASA Astrophysics Data System (ADS)

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

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

2007-04-01

274

Plasticity in Network Organizations Plasticity in Network Organizations  

E-print Network

Plasticity in Network Organizations Paper: Plasticity in Network Organizations Saad Alqithami is plasticity. A model is presented for spontaneously formed NO and the quality of plasticity is discussed synergize with the allies of groups. This group awareness is essen- tial to organizational cohesion

Hexmoor, Henry

275

Core collapse supernovae: magnetorotational explosion  

E-print Network

Core-collapse supernovae are connected with formation of neutron stars. Part of the gravitation energy is transformed into the energy of the explosion, observed in SN II, SN Ib,c type supernovae. The mechanism of transformation is not simple, because the overwhelming majority of the energy is going into weakly interacting neutrino. The attempts to use this energy for the explosion were not successful during about 40 years of investigation. We consider the explosion mechanism in which the source of energy is the rotation, and magnetic field serves for the transformation of the rotation energy into the energy of explosion. 2-D MHD simulations of this mechanism were performed. After the collapse the core consists of a rapidly rotating proto-neutron star with a differentially rotating envelope. The toroidal part of the magnetic energy generated by the differential rotation grows as quadratic function with time at the initial stage of the evolution of the magnetic field. The linear growth of the toroidal magnetic field is terminated by the development of magnetohydrodynamic instability, when the twisted toroidal component strongly exceeds the poloidal field, leading to a drastic acceleration in the growth of magnetic energy. At the moment when the magnetic pressure becomes comparable to the gas pressure at the periphery of the proto-neutron star the MHD compression wave appears and goes through the envelope of the collapsed core. It transforms into the fast MHD shock and produces a supernova explosion. Our simulations give the energy of the explosion $0.6\\cdot 10^{51}$ ergs. The amount of the mass ejected by the explosion is $\\sim 0.14M_\\odot$. The implicit numerical method, based on the Lagrangian triangular grid of variable structure, was used for the simulations.

G. S. Bisnovatyi-Kogan; S. G. Moiseenko; N. V. Ardeljan

2005-11-07

276

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

277

Careers in Plastics  

NSDL National Science Digital Library

Learn about opportunities for working in the growing field of plastics, including the emerging area of green technologies, in this video segment adapted from Pennsylvania College of Technology and WVIA.

Foundation, Wgbh E.

2010-07-11

278

Find a Plastic Surgeon  

MedlinePLUS

... Buttock Lift Calf Implants Chemical Peel Chin Surgery Cosmetic Surgery Dermabrasion Dermal Fillers Ear Surgery Eyelid Surgery Facelift ... on highly trained board-certified plastic surgeons in cosmetic and reconstructive surgery around the world. Use our free Find a ...

279

Periodontal Plastic Surgery  

MedlinePLUS

... attachment to the teeth is abnormal and bone changes may be evident through x-rays. A dentist ... diagnosis has been made, beginning with conservative behavioral changes and extending to periodontal plastic surgery. Treating Periodontal ...

280

Ophthalmic Plastic Surgery  

Microsoft Academic Search

In the family of ophthalmology subspecialties, ophthalmic plastic surgery is the adopted child. There are probably more differences\\u000a than there are similarities with the other subspecialties. The diseases that oculoplastic surgeons treat are unique, and the\\u000a surgeries they perform are quite different from those of ophthalmology colleagues. These unique attributes of ophthalmic plastic\\u000a surgery warrant special consideration in the study

Tanuj Nakra; Norman Shorr

281

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

282

Coupled Damage and Plasticity Modelling in Transient Dynamic Analysis of Concrete  

E-print Network

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

Paris-Sud XI, Université de

283

Breccias related to explosive volcanism  

NASA Astrophysics Data System (ADS)

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

Wolfe, John A.

284

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

285

The Plastic Ocean Michael Gonsior  

E-print Network

Seaton, and Maureen Conte #12;#12;#12;Plastic does not biodegrade it photo-degrades breaking downThe Plastic Ocean Michael Gonsior Bonnie Monteleone, William Cooper, Jennifer O'Keefe, Pamela is the plastic cheese wrap? Unfortunately, marine creatures mistake plastics in the ocean for food #12

Boynton, Walter R.

286

2013 PLASTIC SURGERY VISITING PROFESSOR  

E-print Network

2013 PLASTIC SURGERY VISITING PROFESSOR Dr. Mutaz B. Habal June 6, 2013 McGill University Division of Plastic Surgery 2013 PLASTIC SURGERY VISITING PROFESSOR Special thanks to our sponsors: Representative-190 Research Presentations ­ Residents & Students in Plastic Surgery 10:30 am Coffee Break & Posters (Poster

Shoubridge, Eric

287

DEPARTMENT OF PLASTIC SURGERY APPOINTMENTS,  

E-print Network

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

288

The Need for Plastics Education.  

ERIC Educational Resources Information Center

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

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

289

Insensitive fuze train for high explosives  

DOEpatents

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

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

1994-01-04

290

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

291

The Quiet Explosion  

NASA Astrophysics Data System (ADS)

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

2008-07-01

292

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

293

Explosive evaporation in solar flares  

NASA Technical Reports Server (NTRS)

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

Fisher, George H.

1987-01-01

294

Permeability enhancement using explosive techniques  

SciTech Connect

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

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

1980-01-01

295

The vapor pressures of explosives  

SciTech Connect

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

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

2013-01-05

296

Pattern formation in colloidal explosions  

E-print Network

We study the non-equilibrium pattern formation that emerges when magnetically repelling colloids, trapped by optical tweezers, are abruptly released, forming colloidal explosions. For multiple colloids in a single trap we observe a pattern of expanding concentric rings. For colloids individually trapped in a line, we observe explosions with a zigzag pattern that persists even when magnetic interactions are much weaker than those that break the linear symmetry in equilibrium. Theory and computer simulations quantitatively describe these phenomena both in and out of equilibrium. An analysis of the mode spectrum allows us to accurately quantify the non-harmonic nature of the optical traps. Colloidal explosions provide a new way to generate well-characterized non-equilibrium behaviour in colloidal systems.

Arthur V. Straube; Ard A. Louis; Jörg Baumgartl; Clemens Bechinger; Roel P. A. Dullens

2010-09-10

297

Studies on Shock Attenuation in Plastic Materials and Applications in Detonation Wave Shaping  

NASA Astrophysics Data System (ADS)

Pressure in plastic materials attenuates due to change of impedance, phase change in the medium and plastic deformation. A lot of theoretical and experimental efforts have been devoted to the attenuation of shock wave produced by the impact of explosive driven flyer plate. However comparatively less work has been done on the attenuation of shock waves due to contact explosive detonation. Present studies deal with the attenuation of explosive driven shock waves in various plastic materials and its applications in design of Hybrid Detonation Wave Generator In present work shock attenuating properties of different polymers such as Perspex, Teflon, nylon, polypropylene and viton has been studied experimentally using rotating mirror streak camera and electrical position pins. High explosive RDX/TNT and OCTOL of diameter 75-100mm and thickness 20 to 50mm were detonated to induce shock wave in the test specimens. From experimental determined shock velocity at different locations the attenuation in shock pressure was calculated. The attenuation of shock velocity with thickness in the material indicates exponential decay according to relation US = UOexp(-ax). In few of the experiments manganin gauge of resistance 50 ohms was used to record stress time profile across shock wave. The shock attenuation data of Viton has successfully been used in the design of hybrid detonation wave generator using Octol as high explosive. While selecting a material it was ensured that the attenuated shock remains strong enough to initiate an acceptor explosive. Theoretical calculation were supported by Autodyne 2D hydro-code simulation which were validated with the experiments conducted using high speed streak photography and electrical shock arrival pins. Shock attenuation data of Perspex was used to establishing card gap test and wedge test in which test items is subjected to known pressure pulse by selecting the thickness of the plastic material.

Khurana, Ritu; Gautam, P. C.; Rai, Rajwant; Kumar, Anil; Sharma, A. C.; Singh, Manjit, Dr

2012-07-01

298

Explosive coalescence of magnetic islands  

NASA Technical Reports Server (NTRS)

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

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

1986-01-01

299

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

NASA Technical Reports Server (NTRS)

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

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

1985-01-01

300

Producing a computer generated explosive effect  

E-print Network

This thesis provides a process for a computer generated (CG) effects animator wishing to produce computer generated explosive effects using Alias|Wavefront Power Animator and Composer software. A study of the physical phenomena of real explosions...

Mao, Wei

2012-06-07

301

Apparatus for monitoring linear explosive performance  

NASA Technical Reports Server (NTRS)

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

Bement, L. J.

1974-01-01

302

30 CFR 56.6102 - Explosive material storage practices.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 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...

2010-07-01

303

27 CFR 555.63 - Explosives magazine changes.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 2013-04-01 false Explosives magazine changes. 555.63 Section 555...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Licenses and...

2013-04-01

304

30 CFR 56.6905 - Protection of explosive material.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Protection of explosive material. 56.6905 Section 56...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives General Requirements § 56.6905 Protection of explosive material. (a) Explosive...

2011-07-01

305

27 CFR 555.63 - Explosives magazine changes.  

Code of Federal Regulations, 2012 CFR

... 2012-04-01 2010-04-01 true Explosives magazine changes. 555.63 Section 555...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Licenses and...

2012-04-01

306

30 CFR 57.6903 - Burning explosive material.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

307

30 CFR 57.6305 - Unused explosive material.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

308

30 CFR 57.6302 - Separation of explosive material.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Separation of explosive material. 57.6302 Section...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives Transportation-Surface and Underground § 57.6302 Separation of explosive material. Explosives and...

2010-07-01

309

30 CFR 56.6305 - Unused explosive material.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Unused explosive material. 56.6305 Section 56.6305...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Use § 56.6305 Unused explosive material. Unused explosive material...

2010-07-01

310

27 CFR 555.109 - Identification of explosive materials.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Identification of explosive materials. 555.109 Section 555.109...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Conduct of...

2010-04-01

311

27 CFR 555.63 - Explosives magazine changes.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 2010-04-01 false Explosives magazine changes. 555.63 Section 555...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Licenses and...

2010-04-01

312

30 CFR 57.6905 - Protection of explosive material.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Protection of explosive material. 57.6905 Section 57...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives General Requirements-Surface and Underground § 57.6905 Protection of explosive material. (a) Explosive...

2012-07-01

313

30 CFR 56.6302 - Separation of explosive material.  

... 2014-07-01 false Separation of explosive material. 56.6302 Section 56.6302...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Use § 56.6302 Separation of explosive material. Explosives and blasting...

2014-07-01

314

30 CFR 57.6305 - Unused explosive material.  

Code of Federal Regulations, 2012 CFR

... 2012-07-01 false Unused explosive material. 57.6305 Section 57...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives Transportation-Surface and Underground § 57.6305 Unused explosive material. Unused explosive...

2012-07-01

315

30 CFR 56.6903 - Burning explosive material.  

...2014-07-01 2014-07-01 false Burning explosive material. 56.6903 Section 56...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives General Requirements § 56.6903 Burning explosive material. If explosive material...

2014-07-01

316

30 CFR 57.6903 - Burning explosive material.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Burning explosive material. 57.6903 Section...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives General Requirements-Surface and Underground § 57.6903 Burning explosive material. If explosive...

2011-07-01

317

30 CFR 57.6305 - Unused explosive material.  

... 2014-07-01 false Unused explosive material. 57.6305 Section 57...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives Transportation-Surface and Underground § 57.6305 Unused explosive material. Unused explosive...

2014-07-01

318

30 CFR 56.6905 - Protection of explosive material.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

319

27 CFR 555.109 - Identification of explosive materials.  

Code of Federal Regulations, 2011 CFR

... 2010-04-01 true Identification of explosive materials. 555.109 Section 555.109...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Conduct of...

2011-04-01

320

30 CFR 56.6302 - Separation of explosive material.  

Code of Federal Regulations, 2011 CFR

... 2011-07-01 false Separation of explosive material. 56.6302 Section 56.6302...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Use § 56.6302 Separation of explosive material. Explosives and blasting...

2011-07-01

321

30 CFR 75.1315 - Boreholes for explosives.  

...2014-07-01 false Boreholes for explosives. 75.1315 Section 75.1315 ...SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1315 Boreholes for explosives. (a) All explosives fired...

2014-07-01

322

30 CFR 57.6302 - Separation of explosive material.  

...2014-07-01 false Separation of explosive material. 57.6302 Section...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives Transportation-Surface and Underground § 57.6302 Separation of explosive material. Explosives and...

2014-07-01

323

30 CFR 56.6903 - Burning explosive material.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Burning explosive material. 56.6903 Section 56...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives General Requirements § 56.6903 Burning explosive material. If explosive material...

2012-07-01

324

30 CFR 75.1315 - Boreholes for explosives.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Boreholes for explosives. 75.1315 Section 75.1315 ...SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1315 Boreholes for explosives. (a) All explosives fired...

2011-07-01

325

30 CFR 57.6905 - Protection of explosive material.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Protection of explosive material. 57.6905 Section 57...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives General Requirements-Surface and Underground § 57.6905 Protection of explosive material. (a) Explosive...

2011-07-01

326

30 CFR 75.1315 - Boreholes for explosives.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Boreholes for explosives. 75.1315 Section 75.1315 ...SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1315 Boreholes for explosives. (a) All explosives fired...

2012-07-01

327

30 CFR 75.1315 - Boreholes for explosives.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Boreholes for explosives. 75.1315 Section 75.1315 ...SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1315 Boreholes for explosives. (a) All explosives fired...

2013-07-01

328

30 CFR 57.6903 - Burning explosive material.  

...2014-07-01 false Burning explosive material. 57.6903 Section...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives General Requirements-Surface and Underground § 57.6903 Burning explosive material. If explosive...

2014-07-01

329

30 CFR 57.6302 - Separation of explosive material.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

330

30 CFR 57.6302 - Separation of explosive material.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Separation of explosive material. 57.6302 Section...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives Transportation-Surface and Underground § 57.6302 Separation of explosive material. Explosives and...

2011-07-01

331

27 CFR 555.205 - Movement of explosive materials.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Movement of explosive materials. 555.205 Section 555.205...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Storage §...

2010-04-01

332

30 CFR 56.6305 - Unused explosive material.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Unused explosive material. 56.6305 Section 56.6305...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Use § 56.6305 Unused explosive material. Unused explosive material...

2011-07-01

333

30 CFR 57.6305 - Unused explosive material.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Unused explosive material. 57.6305 Section 57...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives Transportation-Surface and Underground § 57.6305 Unused explosive material. Unused explosive...

2010-07-01

334

27 CFR 555.205 - Movement of explosive materials.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Movement of explosive materials. 555.205 Section 555.205...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Storage §...

2013-04-01

335

30 CFR 56.6302 - Separation of explosive material.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Separation of explosive material. 56.6302 Section 56.6302...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Use § 56.6302 Separation of explosive material. Explosives and blasting...

2010-07-01

336

30 CFR 57.6903 - Burning explosive material.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Burning explosive material. 57.6903 Section...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives General Requirements-Surface and Underground § 57.6903 Burning explosive material. If explosive...

2010-07-01

337

30 CFR 56.6903 - Burning explosive material.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Burning explosive material. 56.6903 Section 56...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives General Requirements § 56.6903 Burning explosive material. If explosive material...

2011-07-01

338

27 CFR 555.202 - Classes of explosive materials.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Classes of explosive materials. 555.202 Section 555.202...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Storage §...

2010-04-01

339

30 CFR 56.6905 - Protection of explosive material.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Protection of explosive material. 56.6905 Section 56...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives General Requirements § 56.6905 Protection of explosive material. (a) Explosive...

2010-07-01

340

27 CFR 555.202 - Classes of explosive materials.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2010-04-01 true Classes of explosive materials. 555.202 Section 555.202...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Storage §...

2012-04-01

341

27 CFR 555.109 - Identification of explosive materials.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Identification of explosive materials. 555.109 Section 555.109...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Conduct of...

2013-04-01

342

30 CFR 56.6905 - Protection of explosive material.  

...2014-07-01 false Protection of explosive material. 56.6905 Section 56...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives General Requirements § 56.6905 Protection of explosive material. (a) Explosive...

2014-07-01

343

30 CFR 75.1315 - Boreholes for explosives.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Boreholes for explosives. 75.1315 Section 75.1315 ...SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1315 Boreholes for explosives. (a) All explosives fired...

2010-07-01

344

27 CFR 555.205 - Movement of explosive materials.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2010-04-01 true Movement of explosive materials. 555.205 Section 555.205...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Storage §...

2011-04-01

345

29 CFR 1926.903 - Underground transportation of explosives.  

Code of Federal Regulations, 2012 CFR

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

2012-07-01

346

27 CFR 555.63 - Explosives magazine changes.  

... 2014-04-01 2014-04-01 false Explosives magazine changes. 555.63 Section 555...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Licenses and...

2014-04-01

347

30 CFR 56.6903 - Burning explosive material.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Burning explosive material. 56.6903 Section 56...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives General Requirements § 56.6903 Burning explosive material. If explosive material...

2010-07-01

348

27 CFR 555.202 - Classes of explosive materials.  

...2014-04-01 2014-04-01 false Classes of explosive materials. 555.202 Section 555.202...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Storage §...

2014-04-01

349

29 CFR 1926.903 - Underground transportation of explosives.  

Code of Federal Regulations, 2011 CFR

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

2011-07-01

350

29 CFR 1926.903 - Underground transportation of explosives.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

351

29 CFR 1926.903 - Underground transportation of explosives.  

Code of Federal Regulations, 2010 CFR

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

2010-07-01

352

27 CFR 555.202 - Classes of explosive materials.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Classes of explosive materials. 555.202 Section 555.202...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Storage §...

2013-04-01

353

30 CFR 56.6903 - Burning explosive material.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

354

30 CFR 56.6305 - Unused explosive material.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Unused explosive material. 56.6305 Section 56.6305...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Use § 56.6305 Unused explosive material. Unused explosive material...

2012-07-01

355

30 CFR 57.6305 - Unused explosive material.  

Code of Federal Regulations, 2011 CFR

... 2011-07-01 false Unused explosive material. 57.6305 Section 57...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives Transportation-Surface and Underground § 57.6305 Unused explosive material. Unused explosive...

2011-07-01

356

27 CFR 555.109 - Identification of explosive materials.  

Code of Federal Regulations, 2012 CFR

... 2010-04-01 true Identification of explosive materials. 555.109 Section 555.109...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Conduct of...

2012-04-01

357

27 CFR 555.63 - Explosives magazine changes.  

Code of Federal Regulations, 2011 CFR

... 2011-04-01 2010-04-01 true Explosives magazine changes. 555.63 Section 555...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Licenses and...

2011-04-01

358

30 CFR 57.6302 - Separation of explosive material.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Separation of explosive material. 57.6302 Section...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives Transportation-Surface and Underground § 57.6302 Separation of explosive material. Explosives and...

2012-07-01

359

27 CFR 555.205 - Movement of explosive materials.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2010-04-01 true Movement of explosive materials. 555.205 Section 555.205...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Storage §...

2012-04-01

360

30 CFR 56.6302 - Separation of explosive material.  

Code of Federal Regulations, 2012 CFR

... 2012-07-01 false Separation of explosive material. 56.6302 Section 56.6302...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Use § 56.6302 Separation of explosive material. Explosives and blasting...

2012-07-01

361

30 CFR 57.6905 - Protection of explosive material.  

...2014-07-01 false Protection of explosive material. 57.6905 Section 57...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives General Requirements-Surface and Underground § 57.6905 Protection of explosive material. (a) Explosive...

2014-07-01

362

30 CFR 57.6903 - Burning explosive material.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Burning explosive material. 57.6903 Section...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives General Requirements-Surface and Underground § 57.6903 Burning explosive material. If explosive...

2012-07-01

363

29 CFR 1926.903 - Underground transportation of explosives.  

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

2014-07-01

364

30 CFR 56.6302 - Separation of explosive material.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

365

30 CFR 57.6905 - Protection of explosive material.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Protection of explosive material. 57.6905 Section 57...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives General Requirements-Surface and Underground § 57.6905 Protection of explosive material. (a) Explosive...

2010-07-01

366

27 CFR 555.202 - Classes of explosive materials.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2010-04-01 true Classes of explosive materials. 555.202 Section 555.202...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Storage §...

2011-04-01

367

30 CFR 56.6305 - Unused explosive material.  

...2014-07-01 2014-07-01 false Unused explosive material. 56.6305 Section 56.6305...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Use § 56.6305 Unused explosive material. Unused explosive material...

2014-07-01

368

27 CFR 555.109 - Identification of explosive materials.  

...2014-04-01 false Identification of explosive materials. 555.109 Section 555.109...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Conduct of...

2014-04-01

369

30 CFR 56.6305 - Unused explosive material.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

370

30 CFR 56.6905 - Protection of explosive material.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Protection of explosive material. 56.6905 Section 56...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives General Requirements § 56.6905 Protection of explosive material. (a) Explosive...

2012-07-01

371

27 CFR 555.205 - Movement of explosive materials.  

...2014-04-01 2014-04-01 false Movement of explosive materials. 555.205 Section 555.205...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Storage §...

2014-04-01

372

30 CFR 57.6905 - Protection of explosive material.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

373

Consumer hazards of plastics.  

PubMed Central

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

Wiberg, G S

1976-01-01

374

Characterization of secondary grain dust explosions  

E-print Network

times greater than the primary minimum explosive concentration and a secondary explosion can be generated from a primary dust concentration which is at least 3. 25 t1mes greater than the minimum explosive concentration. Further- more, the explos1... Bredemeyer for their help in running explosion tests and in preparing numerous figures for this thesis. Thanks to Debi Graff for her help, particularly the size analysis runs on the Coulter Counter. To my husband. and best, friend, Craig, your love...

Schulman, Cheryl Wendler

2012-06-07

375

Mechanical model of domestic gas explosion load  

Microsoft Academic Search

With the increase of domestic gas consumption in cities and towns in China, gas explosion accidents happened rather frequently,\\u000a and many structures were damaged greatly. Rational physical design could protect structures from being destroyed, but the\\u000a character of explosion load must be learned firstly by establishing a correct mechanical model to simulate vented gas explosions.\\u000a The explosion process has been

Yongli Han; Longzhu Chen

2008-01-01

376

Statistical analysis of high explosive detonation data  

SciTech Connect

This study investigates the detonation behavior of two different high explosive compounds, PBX 9404 and PBX 9502. One reason these two high explosives were selected is because data is abundant relative to other types of high explosives. Statistical analysis of data for two different high explosives was performed. The goal of the analysis was to determine how the probability of detonation varies for different run lengths and pressures.

NONE

1998-05-10

377

Explosion welding and cutting in aerospace engineering  

NASA Astrophysics Data System (ADS)

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

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

378

USING 1-D RADAR OBSERVATIONS TO DETECT A SPACE EXPLOSION CORE AMONG THE EXPLOSION FRAGMENTS  

E-print Network

USING 1-D RADAR OBSERVATIONS TO DETECT A SPACE EXPLOSION CORE AMONG THE EXPLOSION FRAGMENTS Science Las Cruces, NM 88003 ABSTRACT A radar observes the result of a space explosion. Due to radar's low astronomical processes are slow; however, sometimes, space explosions happen: starts become supernovae, plan

Kreinovich, Vladik

379

USING 1D RADAR OBSERVATIONS TO DETECT A SPACE EXPLOSION CORE AMONG THE EXPLOSION FRAGMENTS  

E-print Network

USING 1­D RADAR OBSERVATIONS TO DETECT A SPACE EXPLOSION CORE AMONG THE EXPLOSION FRAGMENTS. Computer Science Las Cruces, NM 88003 ABSTRACT A radar observes the result of a space explosion. Due astronomical processes are slow; however, sometimes, space explosions happen: starts become supernovae, plan

Kreinovich, Vladik

380

Curved detonation fronts in solid explosives 1 Curved detonation fronts in solid explosives#  

E-print Network

Curved detonation fronts in solid explosives 1 Curved detonation fronts in solid explosives ###. At the edges of the explosive# D n ### is supplemented with boundary conditons. By direct numerical simulation for simulating complex explosive#containing systems. Key words# Detonation# Curvature e#ect# Edge interactions

Aslam, Tariq

381

Curved detonation fronts in solid explosives 1 Curved detonation fronts in solid explosives  

E-print Network

Curved detonation fronts in solid explosives 1 Curved detonation fronts in solid explosives(). At the edges of the explosive, Dn() is supplemented with boundary conditons. By direct numerical simulation for simulating complex explosive-containing systems. Key words: Detonation, Curvature eect, Edge interactions

Aslam, Tariq

382

THE CHARACTERIZATION OF SEISMIC AND INFRASOUND SIGNALS FROM MINING EXPLOSIONS a) Explosion Source  

E-print Network

THE CHARACTERIZATION OF SEISMIC AND INFRASOUND SIGNALS FROM MINING EXPLOSIONS a) Explosion Source CONTRIBUTIONS TO MINING EXPLOSIONS Black Thunder Cast Blast REGIONAL SYNTHETIC| AMPLITUDES COMPARED TO DATA body Morenci Event 7 In-mine acoustic Log Freq (Hz) 0 100 RelAmp(dB) ExplosiveWeight(lbs) 10,000 100,000 1

Stump, Brian W.

383

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

384

Measuring explosive non-ideality  

SciTech Connect

The sonic reaction zone length may be measured by four methods: (1) size effect, (2) detonation front curvature, (3) crystal interface velocity and (4) in-situ gauges. The amount of data decreases exponentially from (1) to (4) with there being almost no gauge data for prompt detonation at steady state. The ease and clarity of obtaining the reaction zone length increases from (1) to (4). The method of getting the reaction zone length, , is described for the four methods. A measure of non-ideality is proposed: the reaction zone length divided by the cylinder radius. N = /R{sub o}. N = 0 for true ideality. It also decreases with increasing radius as it should. For N < 0.10, an equilibrium EOS like the JWL may be used. For N > 0.10, a time-dependent description is essential. The crystal experiment, which measures the particle velocity of an explosive-transparent material interface, is presently rising in importance. We examine the data from three experiments and apply: (1) an impedance correction that transfers the explosive C-J particle velocity to the corresponding value for the interface, and (2) multiplies the interface time by 3/4 to simulate the explosive speed of sound. The result is a reaction zone length comparable to those obtained by other means. A few explosives have reaction zones so small that the change of slope in the particle velocity is easily seen.

Souers, P C

1999-02-17

385

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

386

Explosive Separation of Electrical Connectors  

NASA Technical Reports Server (NTRS)

Concept proposed for separating electrical cable that connects the Space Shuttle to deployable payloads could be used to sever electrical connections in other inaccessible environments. Although triggered explosively, connector would not release combustion products that could damage sensitive electronics. Suggested applications are undersea exploration, chemical processing and areas with high levels of radiation.

Barbour, R. T.

1982-01-01

387

Gas Explosion Characterization, Wave Propagation  

E-print Network

mixtures of methane, oxygen and nitrogen, contained within spherical balloons with controlled initial ignition. This develop- ment has made it still more urgent to consider explosion loads in the design phase;- 6 - 2. INTRODUCTION This report describes a series of small-scale experiments carried out

388

Turbulent Combustion in SDF Explosions  

SciTech Connect

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

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

2009-11-12

389

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

390

ANALYSIS OF MINING EXPLOSION PERFORMANCE WITH MULTIPLE  

E-print Network

ANALYSIS OF MINING EXPLOSION PERFORMANCE WITH MULTIPLE SENSOR DATA AND PHYSICAL MODELS Brian W Martin Thunder Basin Coal Company Wright, Wyoming #12;Analysis of Mining Explosion Performance 2 1 to Different Types of Mining Explosions · Single Shot · Cast Blast · Coal Fragmentation #12;Analysis of Mining

Stump, Brian W.

391

Doping explosive materials for neutron radiographic enhancement.  

NASA Technical Reports Server (NTRS)

Discussion of studies relating to the selection of doping materials of high neutron absorption usable for enhancing the neutron radiographic imaging of explosive mixtures, without interfering with the proper chemical reaction of the explosives. The results of the studies show that gadolinium oxide is an excellent material for doping explosive mixtures to enhance the neutron radiographic image.

Golliher, K. G.

1971-01-01

392

14 CFR 420.63 - Explosive siting.  

Code of Federal Regulations, 2011 CFR

...A listing of the maximum quantities of liquid and solid propellants and other explosives to be located at each explosive hazard...explosive and the hazard and compatibility group for each liquid propellant; and (3) A description of each activity to be...

2011-01-01

393

14 CFR 420.63 - Explosive siting.  

Code of Federal Regulations, 2010 CFR

...A listing of the maximum quantities of liquid and solid propellants and other explosives to be located at each explosive hazard...explosive and the hazard and compatibility group for each liquid propellant; and (3) A description of each activity to be...

2010-01-01

394

14 CFR 420.63 - Explosive siting.  

Code of Federal Regulations, 2012 CFR

...A listing of the maximum quantities of liquid and solid propellants and other explosives to be located at each explosive hazard...explosive and the hazard and compatibility group for each liquid propellant; and (3) A description of each activity to be...

2012-01-01

395

Culture and Explosion Semiotics, Communication and  

E-print Network

#12;Culture and Explosion #12;Semiotics, Communication and Cognition 1 Editor Paul Cobley Mouton de Gruyter Berlin · New York #12;Culture and Explosion by Juri Lotman edited by Marina Grishakova'tura i vzryv. English] Culture and explosion / by Juri Lotman ; edited by Marina Gri- shakova

Markos, Anton

396

Underwater explosive cutting in ship salvage  

Microsoft Academic Search

The sensitive use of explosives in ship salvage operations is described with a brief review of the physical phenomena involved in underwater explosive cutting. Specific problems encountered in the design and use of shaped charge cutters are identified; actual on site improvisations are summarized from recent and current case histories of ship salvage involving extensive explosive cutting. Prime factors leading

C. Bartholomew; A. Rynecki; D. Saveker

1975-01-01

397

Explosives detection: the problem and prospects  

Microsoft Academic Search

The history of explosives vapor detection includes almost every detection strategy known to man. Initial attempts to utilize these techniques were dismal failures. However, with the development of the Electron Capture Detector (ECD), the first promising detection of explosives vapors became possible. The present commercial explosives detectors detect the higher vapor pressure materials but not the whole spectrum. This paper

Conrad

1984-01-01

398

Explosives: A microsensor for trinitrotoluene vapour  

Microsoft Academic Search

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

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

2003-01-01

399

Polymer sensors for nitroaromatic explosives detection  

Microsoft Academic Search

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

Sarah J. Toal; William C. Trogler

2006-01-01

400

Prediction of Fire Spread Following Nuclear Explosions  

E-print Network

Prediction of Fire Spread Following Nuclear Explosions Craig C. Chandler, Theodore G. Storey spread following nuclear explosions. Berkeley, Calif., Pacific SW. Forest & Range Expt Sta. 110 pp nuclear explosions. Berkeley, Calif., Pacific SW. Forest & Range Expt Sta. 110 pp., illus. (U.S. Forest

Standiford, Richard B.

401

Partitioning effect on a dust explosion  

E-print Network

1 Partitioning effect on a dust explosion J.M. Pascaud Université d'Orléans 63, avenue de Lattre de explosion and the formation of overpressures inside a partitioned vessel. A calculation methodology of the explosion from one compartment to another adjacent compartment by the means of the hot flow through

Paris-Sud XI, Université de

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

Explosion risks from nanomaterials Jacques Bouillard1  

E-print Network

Explosion risks from nanomaterials Jacques Bouillard1 , Alexis Vignes1 , Olivier Dufaud2 , Laurent necessitates a transdisciplinary approach. A commonly forgotten and/or misunderstood risk is that of explosion nanotubes. Concerning carbon nanotubes (CNTs), their market is positioned to "grow explosively" to reach 540

Paris-Sud XI, Université de

404

14 CFR 420.63 - Explosive siting.  

...2014-01-01 2014-01-01 false Explosive siting. 420.63 Section 420.63...Responsibilities of a Licensee § 420.63 Explosive siting. (a) Except as otherwise...configuration of the launch site follows its explosive site plan, and the licensee's...

2014-01-01

405

Numerical approximation of SDE with explosions.  

E-print Network

Numerical approximation of SDE with explosions. Joint work with Ju´an D´avila, U. de Chile Juli of the largest crack. The explosion time corresponds to the time of ultimate damage or fatigue failure in the material. #12;The Feller Test for Explosions provides a precise criteria to de- termine, in terms of b

Groisman, Pablo

406

Report on Explosives Repository Testing  

SciTech Connect

Repositories have been in use at Lawrence Livermore National Laboratories for storage of ten grams or less explosives samples for about twenty years. A previous Repository testing program detailed in UCID 19219 reported that a standard repository would contain ten grams of high explosive but the repository drawer would open. It further recommended a non-propagating array that would allow storage of quantities of explosives in a repository drawer, however; the capability of the proposed nonpropagating array was never verified. A series of tests was undertaken to verify the capability of the proposed array to provide non-propagation between 10-gram samples stored within that array and to document the extent of damage to the stored explosives, the array and the repository. Testing has verified that the standard four-drawer repository configured per UCID 19219 may store a 10-gram explosive sample without propagation to the other materials stored in the repository. Should a detonation of a 10-gram sample occur, the four-drawer repository will be damaged but does not appear to create a significant fragment hazard and does not sustain significant damage. The drawer containing the test charge opens quickly and fully releasing the detonation overpressure. Testing of a standard two-drawer repository verified that the array will prevent propagation, however; the repository was totally destroyed and would present a physical hazard to personnel and equipment in the immediate area of the repository. An additional test of a standard repository was conducted to verify current storage practices for detonators using detonators in the Mound non-propagating packing configuration. The repository drawer tested sustained minimal damage and no propagation between stored detonators. Therefore, storage of detonators in a standard Mound or Manufacturer non-propagating configuration in either a two-drawer or four-drawer repository is acceptable.

Crouch, L; Dotts, J E

2000-03-15

407

2/13/2014 Household explosion replaces population explosion as world concern -UPI.com http://www.upiasia.com/Science-Technology/2014/02/11/Household-explosion-replaces-population-explosion-as-world-concern/UPI-87811392152198/ 1/1  

E-print Network

2/13/2014 Household explosion replaces population explosion as world concern - UPI.com http://www.upiasia.com/Science-Technology/2014/02/11/Household-explosion-replaces-population-explosion-as-world-concern/UPI-87811392152198/ 1 & Technology / Household explosion replaces population explosion as world concern Science & Technology

408

Useful Plastic Items Available  

NASA Astrophysics Data System (ADS)

It has recently come to our attention that hospitals are a source of plastic items that can be used by chemistry teachers at the precollege or college level. These items are discarded from operating rooms but have not come in contact with any of the patients; therefore, they are perfectly safe to use.

Sherman, Marie

1995-11-01

409

Hypnosis in Plastic Surgery  

Microsoft Academic Search

This paper reports on three years experience of the use of hypnosis at the Plastic Surgical Unit of Whiston Hospital in Lancashire, England. This therapy has primarily been used as a psychotherapeutic support for 13 patients undergoing pedicle and flap graft surgery; this resulted in a greatly improved morale and marked reduction in the total drug requirement. Ego-strengthening has been

David L. Scott

1975-01-01

410

Preserving in Plastic.  

ERIC Educational Resources Information Center

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

Wahla, James

1985-01-01

411

Plastics in Perspective.  

ERIC Educational Resources Information Center

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

Bergandine, David R.; Holm, D. Andrew

412

Fused Plastic Wallet  

NSDL National Science Digital Library

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

Centers, Oakland D.

2012-01-01

413

Shock-Sensitive Chemicals Materials classified as explosives and chemicals that can act as explosives. If the material is maintained  

E-print Network

Shock-Sensitive Chemicals Materials classified as explosives and chemicals that can act as explosives. If the material is maintained in inventory for its explosive properties, it must be treated as an explosive, and Administrative Requirement (AR) 6-6, "Explosives" and the U.S. DOE Explosive Safety Manual

de Lijser, Peter

414

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

415

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

Matyáš, Robert; Šelešovský, Jakub; Musil, Tomáš

2012-04-30

416

Retrofit for Plastic Resin Driers  

E-print Network

RETROFIT FOR PLASTIC RESIN DRIERS BABU JOSEPH PH.D. Supervising Engineer Southern California Edison Company, Irwindale, California GEORGE THURO Thuro, & Associates, Costa Mesa, California Plastic resins used in injection molding have... FOR PLASTIC RESIN DRIERS BABU JOSEPH PH.D. Supervising Engineer Southern California Edison Company, Irwindale, California GEORGE THURO Thuro, & Associates, Costa Mesa, California Plastic resins used in injection molding have to be dried to specified levels...

Joseph, B.; Thuro, G.

417

Occupational hazards in plastic surgery  

Microsoft Academic Search

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

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

1995-01-01

418

Plastics for Elementary School Children  

ERIC Educational Resources Information Center

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

Hanson, Jack

1977-01-01

419

Plasticity at the micron scale  

Microsoft Academic Search

Over a scale which extends from about a fraction of a micron to tens of microns, metals display a strong size-dependence when deformed non uniformly into the plastic range: smaller is stronger. This effect has important implications for an increasing number of applications in electronics, structural materials and MEMS. Plastic behavior at this scale cannot be characterized by conventional plasticity

John W. Hutchinson

2000-01-01

420

Tomorrow’s plastic world  

NASA Astrophysics Data System (ADS)

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 possibilites 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

2005-09-01

421

Printable sensors for explosive detonation  

NASA Astrophysics Data System (ADS)

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

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

2014-10-01

422

Overheated detonation in condensed explosives  

SciTech Connect

The authors examine the overheating of a chemical detonation wave, which results in hybrid detonation processes, for example, photochemical or electrochemical detonation, depending on the source. The schemes for obtaining the overheated detonation are shown. Analysis has shown that: normal stationary overheated detonation waves are possible when the overheating power density is constant, just as when the specific energy of overheating is constant; the use of the ''gas'' equation of state for describing overheated detonation in condensed explosives yields wave parameters which are too high; and the assumption that the chemical energy released in the explosive is independent of the overheating energy also leads to wave parameters which are too high, and the overestimation increases as the overheating is intensified.

Tarzhanov, V.I.

1986-03-01

423

Explosives detection system and method  

DOEpatents

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

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

2007-12-11

424

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

425

Peaceful utilization of nuclear explosions  

SciTech Connect

Today the utilization of nuclear energy is mostly only related with the generation of electricity. There are, however, a number of further possibilities of application, beginning with the generation and application of radioactive isotopes, via nuclear reactors as marine and rocket propulsions, up to the utilization of nuclear explosions. The peaceful utilization of nuclear explosions was the subject of the American project 'Plough-Share' which had been started more than 20 years ago but definitely given up in 1977 by the Carter-government which is hostile to nuclear energy. Thus a programme was stopped which had opened up large fields of a virgin territory to science and technology. Dr. Gary Higgins of the Californian Lawrence Livermore Lab., a pioneer in that field, describes the history and successes of a most promising project of the 'Treasury Nuclear Energy'.

Higgins, G.

1982-08-01

426

Photographic laboratory studies of explosions.  

NASA Technical Reports Server (NTRS)

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

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

1973-01-01

427

Applying NASA's explosive seam welding  

NASA Technical Reports Server (NTRS)

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

Bement, Laurence J.

1991-01-01

428

Seismic verification of underground explosions  

SciTech Connect

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

Glenn, L.A.

1985-06-01

429

Thermal explosion of autocatalytic reaction  

Microsoft Academic Search

Analytical and numerical solutions are used to determine the critical conditions for thermal explosion of autocatalytic reaction. The solutions covers both the reaction governed by the Arrhenius kinetics equation and the Frank-Kamenetskii approximation for that equation. The definition of criticality as the point at which d2?\\/d?2=0, d3?\\/d?3=0 and d?\\/d??0 is used here. The study is dealt with low and high

Saad A. El-Sayed

2003-01-01

430

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

431

Thermally stable emulsion explosive composition  

SciTech Connect

A thermally stable, cap-sensitive, water-in-oil emulsion explosive composition is described which has a discontinuous aqueous oxidizer salt solution phase containing calcium nitrate, a continuous oil or water-immiscible liquid or organic phase, an emulsifier, and a density reducing agent. The salt solution contains calcium nitrate in an amount of at least 20% by weight based on the total composition. 9 claims.

Sudweeks, W.B.; Lawrence, L.D.

1982-03-30

432

RANCHERO explosive pulsed power experiments  

Microsoft Academic Search

The authors are developing the RANCHERO high explosive pulsed power (HEPP) system to power cylindrically imploding solid-density liners for hydrodynamics experiments. Their near-term goal is to conduct experiments in the regime pertinent to the Atlas capacitor bank. That is, they will attempt to implode liners of ~50 g mass at velocities approaching 15 km\\/sec. The basic building block of the

J. H. Goforth; W. A. Anderson; E. V. Armijo; W. L. Atchison; J. J. Bartos; D. A. Clark; R. D. Day; W. J. Deninger; R. J. Faehl; C. M. Fowler; F. P. Garcia; O. F. Garcia; D. H. Herrera; T. J. Herrera; R. K. Keinigs; J. C. King; J. R. Lindemuth; E. A. Lopez; E. C. Martinez; D. Martinez; J. A. McGuire; D. Morgan; H. Oona; D. M. Oro; J. V. Parker; R. B. Randolph; R. E. Reinovsky; G. Rodriguez; J. L. Stokes; F. C. Sena; L. J. Tabaka; D. G. Tasker; A. J. Taylor; D. T. Torres; H. D. Anderson; W. B. Broste; J. B. Johnson

1999-01-01

433

Splicing Wires Permanently With Explosives  

NASA Technical Reports Server (NTRS)

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

Bement, Laurence J.; Kushnick, Anne C.

1990-01-01

434

Thermodynamic States in Explosion Fields  

SciTech Connect

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

Kuhl, A L

2010-03-12

435

The Arson & Explosives National Repository  

NSDL National Science Digital Library

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

436

Paper or Plastic?  

NSDL National Science Digital Library

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

2008-09-11

437

Stress-gradient plasticity  

PubMed Central

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

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

2011-01-01

438

Compensatory plasticity: time matters  

PubMed Central

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

Lazzouni, Latifa; Lepore, Franco

2014-01-01

439

Cutting the plastic  

Microsoft Academic Search

Students from The University of Notre Dame Australia recently turned Coles Supermarket Fremantle into their “laboratory” for a week, in an attempt to encourage shoppers to abandon plastic shopping bags in favour of the environmentally-friendly alternatives.\\u000aThrough collaboration between the University, City of Fremantle and Coles; Notre Dame environmental education students are getting the chance to learn about some of

Michelle Ebbs

2005-01-01

440

Compensatory plasticity: time matters.  

PubMed

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

Lazzouni, Latifa; Lepore, Franco

2014-01-01

441

49 CFR 173.62 - Specific packaging requirements for explosives.  

Code of Federal Regulations, 2013 CFR

...reconstituted wood (4F). fiberboard (4G). plastics, expanded (4H1). plastics...reconstituted wood (4F). fiberboard (4G). plastics, expanded (4H1). plastics...reconstituted wood (4F). fiberboard (4G). plastics, expanded (4H1)....

2013-10-01

442

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

NASA Technical Reports Server (NTRS)

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

Bement, L. J. (inventor)

1974-01-01

443

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

2007-01-01

444

Brookhaven National Laboratory/Photon Sciences Subject: NSLS Explosives Training (de minimis quantities)  

E-print Network

Brookhaven National Laboratory/Photon Sciences Subject: NSLS Explosives Training (de minimis. Ackerman Approved By: K. Klaus Explosives Hazards Experimentation at NSLS may include explosives in small minimis quantities of explosives, (explosives, and explosives

Ohta, Shigemi

445

Plastics eLearning  

NSDL National Science Digital Library

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

2009-11-25

446

Plasticity of amyloid fibrils†  

PubMed Central

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

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

2008-01-01

447

Microelectronics plastic molded packaging  

SciTech Connect

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

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

1997-02-01

448

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

SciTech Connect

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

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

1998-03-01

449

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

Code of Federal Regulations, 2010 CFR

...receipt, possession, or distribution of explosive materials. 555.26 Section 555.26...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES...

2010-04-01

450

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

Code of Federal Regulations, 2012 CFR

...receipt, possession, or distribution of explosive materials. 555.26 Section 555.26...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES...

2012-04-01

451

27 CFR 555.221 - Requirements for display fireworks, pyrotechnic compositions, and explosive materials used in...  

Code of Federal Regulations, 2010 CFR

...fireworks, pyrotechnic compositions, and explosive materials used in assembling fireworks or...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Storage §...

2010-04-01

452

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

Code of Federal Regulations, 2011 CFR

...receipt, possession, or distribution of explosive materials. 555.26 Section 555.26...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES...

2011-04-01

453

27 CFR 555.221 - Requirements for display fireworks, pyrotechnic compositions, and explosive materials used in...  

Code of Federal Regulations, 2012 CFR

...fireworks, pyrotechnic compositions, and explosive materials used in assembling fireworks or...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Storage §...

2012-04-01

454

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

Code of Federal Regulations, 2013 CFR

...receipt, possession, or distribution of explosive materials. 555.26 Section 555.26...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES...

2013-04-01

455

27 CFR 555.221 - Requirements for display fireworks, pyrotechnic compositions, and explosive materials used in...  

Code of Federal Regulations, 2013 CFR

...fireworks, pyrotechnic compositions, and explosive materials used in assembling fireworks or...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Storage §...

2013-04-01

456

27 CFR 555.221 - Requirements for display fireworks, pyrotechnic compositions, and explosive materials used in...  

...fireworks, pyrotechnic compositions, and explosive materials used in assembling fireworks or...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Storage §...

2014-04-01

457

27 CFR 555.221 - Requirements for display fireworks, pyrotechnic compositions, and explosive materials used in...  

Code of Federal Regulations, 2011 CFR

...fireworks, pyrotechnic compositions, and explosive materials used in assembling fireworks or...BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Storage §...

2011-04-01

458

Explosion pulping of bagasse and wheat straw  

SciTech Connect

Bagasse and wheat straw were soda-pulped in a digester at 200 degrees under N pressure of up to 13.8 MPa, followed by explosive discharge through nozzles to give pulp having lower yield and higher initial freeness than batch soda pulp. Explosion pulping required less NaOH than conventional batch soda pulping, and the properties of explosion pulp obtained were similar to those of batch soda pulp at a given freeness.

Mamers, H.; Yuritta, J.P.; Menz, D.J.

1981-01-01

459

Air Activation Following an Atmospheric Explosion  

SciTech Connect

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

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

2013-03-13

460

Explosions on a gas-vacuum interface  

SciTech Connect

A finite-difference computer code is used to calculate the time development of an explosion on a gas-vacuum interface. An analytic theory of the shape of the shock wave produced in the explosion is compared with the results of the computer simulation. The assumptions used in obtaining this analytic solution are verified, and the degree to which the variables describing the explosion are self-similar is examined. Finally, certain consistency relations among the similarity exponents are tested.

Nutt, G.; Klein, L.; Ratcliffe, A.E.

1981-12-01

461

Threat localization in QR explosive detection systems  

Microsoft Academic Search

The detection of explosives for the purpose of aviation security is an important task for preventing terrorism acts and smuggling.\\u000a A number of methods for explosive screening have been developed. For the purpose of aviation security, the inspections are\\u000a performed on passengers, their carry-on luggage, checked baggage, and cargo containers. An effective explosive detection system\\u000a should be capable of reporting

H. Robert; P. J. Prado

2004-01-01

462

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

463

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. In the presented algorithm, the ghost-fluid method is employed to represent the evolving material interfaces as discontinuities on discrete space. The coupling between the materials at these interfaces is achieved by means of a new approximate mixed Riemann solver, developed as part of this research. In addition we present a mixed Riemann solver for a simpler transport model, which ignores compaction effects at the interface. The robustness and accuracy of the developed solvers is demonstrated by comparisons against results from the original ghost-fluid method and exact solutions of model Riemann problems. To allow for more realistic material behaviour, the mixed Riemann solvers are subsequently extended to handle the shock Mie-Grüneisen equation of state, and an iterative procedure is suggested to increase accuracy as required. These mixed Riemann solvers demonstrate their suitability for explosive-solid interactions in two test cases of multi-phase detonations confined by an elastic-plastic solid.

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

2013-11-01

464

Detecting explosive substances by the IR spectrography  

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

465

The explosion problem in a flow  

E-print Network

We consider the explosion problem in an incompressible flow introduced in the paper of H. Berestycki, L. Kagan, G. Joulin and G. Sivashinsky. We use a novel $L^p-L^\\infty$ estimate for elliptic advection-diffusion problems to show that the explosion threshold obeys a positive lower bound which is uniform in the advecting flow. We also identify the flows for which the explosion threshold tends to infinity as their amplitude grows and obtain an effective description of the explosion threshold in the strong flow asymptotics in a two-dimensional one-cell flow.

Henri Berestycki; Alexander Kiselev; Alexei Novikov; Lenya Ryzhik

2009-07-29

466

Method and apparatus for detecting explosives  

DOEpatents

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

Moore, David Steven (Santa Fe, NM)

2011-05-10

467

Green primary explosives: 5-Nitrotetrazolato-N2-ferrate hierarchies  

Microsoft Academic Search

The sensitive explosives used in initiating devices like primers and detonators are called primary explosives. Successful detonations of secondary explosives are accomplished by suitable sources of initiation energy that is transmitted directly from the primaries or through secondary explosive boosters. Reliable initiating mechanisms are available in numerous forms of primers and detonators depending upon the nature of the secondary explosives.

My Hang V. Huynh; Michael D. Coburn; Thomas J. Meyer; Modi Wetzler

2006-01-01

468

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

469

Explosive Detection by Microthermal Analysis  

Microsoft Academic Search

Differential scanning microcalorimetry at high heating rates of ? 300°C\\/s was performed on 30- to 100-µm-size explosive particles using two MEMS-based thermal conductivity gauges in air and under N2. The gauges consist of a thin-film Si3Nx membrane with a centrally located Al thin-film heater, which is surrounded by six thin-film Si\\/Al junctions, creating a temperature-sensitive thermopile (? 1.3 mV\\/K) with an effective sensitive

Asaf Zuck; Jeremy Greenblatt; Adi Zifman; Amalia Zaltsman; Shay Kendler; Gad Frishman; Sheffer Meltzer; Ilanit Fisher

2008-01-01

470

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

471

Explosions  

MedlinePLUS

... available resources by visiting the following websites: Federal Emergency Management Agency American Red Cross Center for Disease Control ... always listen to the instructions given by local emergency management officials.

472

Amorphous Metallic Plastic  

SciTech Connect

We report cerium-based bulk metallic glasses with an exceptionally low glass transition temperature T{sub g}, similar to or lower than that of many polymers. We demonstrate that, in near-boiling water, these materials can be repeatedly shaped, and can thus be regarded as metallic plastics. Their resistance to crystallization permits extended forming times above T{sub g} and ensures an adequate lifetime at room temperature. Such materials, combining polymerlike thermoplastic behavior with the distinctive properties of metallic glasses, are highly unusual for metallic alloys and have great potential in applications and can also facilitate studies of the supercooled liquid state.

Zhang, B.; Zhao, D.Q.; Pan, M.X.; Wang, W.H. [Institute of Physics, Chinese Academy of Sciences, Beijing 100080 (China); Greer, A.L. [Department of Materials Science and Metallurgy, University of Cambridge, Cambridge CB2 3QZ (United Kingdom)

2005-05-27

473

Rehabilitation and plasticity.  

PubMed

Therapies for effective neurorehabiltiation are in part based on brain mechanism commonly described as neuroplasticity. These therapeutic approaches emphasize the re-learning of functionality that was lost due to the injury through reorganization of neural circuits in the remaining intact tissue. Important elements of these therapies are intensive and repetitive training, motivation and potentially interactive devices (therapy "robots") and supportive therapies such as brain stimulation or plasticity inducing medications. Because neuroplasticity-based interventions are complex and multifactorial optimized treatment protocols have to be developed before large clinical trials can provide the evidence of efficacy. PMID:23859967

Luft, Andreas R

2013-01-01

474

Estimates of crater dimensions for near-surface explosions of nuclear and high-explosive sources  

Microsoft Academic Search

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 are used to rank the cratering efficiency of various geologies. NE crater data from dry soil at the Nevada Test Site and from

H. F. Jr

1976-01-01

475

The Formation of a Blast Wave by a Very Intense Explosion. II. The Atomic Explosion of 1945  

E-print Network

The Formation of a Blast Wave by a Very Intense Explosion. II. The Atomic Explosion of 1945 of a blast wave by a very intense explosion. 11. The atomic explosion of 1945 BYSIRGEOBFREYTAYLOR,P.R.S. (Received 10 November 1949) [Plates 7 t o 91 Photographs by J.E. Mack of the first atomic explosion in New

Ravelet, Florent

476

Pre-explosive conduit conditions of the 1997 Vulcanian explosions at Soufrire Hills Volcano, Montserrat: I. Pressure and vesicularity distributions.  

E-print Network

Pre-explosive conduit conditions of the 1997 Vulcanian explosions at Soufrière Hills Volcano of Vulcanian eruptive dynamics is the series of 88 explosions that occurred between August and October 1997 explosion is still poorly understood, but conditions the eruptive style. This study establishes such a pre-explosive

Boyer, Edmond

477

Biodegradable plastics from renewable sources  

Microsoft Academic Search

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

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

2003-01-01

478

Polyolefins as additives in plastics  

SciTech Connect

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

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

1993-12-31

479

Low Frequency Electromagnetic Pulse and Explosions  

SciTech Connect

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

Sweeney, J J

2011-02-01

480

EXPLOSIVE INSTABILITY AND CORONAL HEATING  

SciTech Connect

The observed energy-loss rate from the solar corona implies that the coronal magnetic field has a critical angle at which energy is released. It has been hypothesized that at this critical angle an 'explosive instability' would occur, leading to an enhanced conversion of magnetic energy into heat. In earlier investigations, we have shown that a shear-dependent magnetohydrodynamic process called 'secondary instability' has many of the distinctive features of the hypothetical 'explosive instability'. In this paper, we give the first demonstration that this 'secondary instability' occurs in a system with line-tied magnetic fields and boundary shearing-basically the situation described by Parker. We also show that, as the disturbance due to secondary instability attains finite amplitude, there is a transition to turbulence which leads to enhanced dissipation of magnetic and kinetic energy. These results are obtained from numerical simulations performed with a new parallelized, viscoresistive, three-dimensional code that solves the cold plasma equations. The code employs a Fourier collocation-finite difference spatial discretization, and uses a third-order Runge-Kutta temporal discretization.

Dahlburg, R. B.; Liu, J.-H. [Laboratory for Computational Physics and Fluid Dynamics, Naval Research Laboratory, Washington, DC 20375-5344 (United States); Klimchuk, J. A.; Nigro, G., E-mail: rdahlbur@lcp.nrl.navy.mi [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States)

2009-10-20

481

High temperature two component explosive  

SciTech Connect

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

Mars, J.E.; Poole, D.R.; Schmidt, E.W.; Wang, C.

1981-06-23

482

[Update: blast and explosion trauma].  

PubMed

In recent decades, acoustic shock and explosion traumas have increased in frequency in the general population. Beside the use of fireworks and firearms, airbag ignitions and explosions caused by terror or suicidal acts are also relevant. Depending on duration and strength of the sound pressure affecting the human ear, isolated inner ear damage or additional ear drum perforation and interruption of the middle ear ossicle chain can result. By means of otoscopy, pure tone audiometry, measurement of otoacoustic emissions, and other neurootological examinations, the severity of the trauma can be determined. With prompt and adequate therapy, permanent hearing loss can be minimized. In particular, the measurement of otoacoustic emissions allows conclusions to be made on the functionality of the outer hair cells which are damaged first in most cases. Histological investigations on noise-exposed cochleas show extensive damage to the outer hair cells in the frequency range between 1.0 and 4.0 kHz, which correlates well with audiometric measurements. PMID:21769579

van de Weyer, P S; Praetorius, M; Tisch, M

2011-08-01

483

The locations of cosmic explosions  

NASA Technical Reports Server (NTRS)

When massive stars exhaust their fuel they collapse and often produce the extraordinarily bright explosions known as core-collapse supernovae. Recently, it has become apparent that stellar collapse can power the even more brilliant relativistic explosions known as long-duration gamma-ray bursts. In some cases, a gamma-ray burst and a supernova have been observed from the same event. One would thus expect that gamma-ray bursts and supernovae should be found in similar environments. Here we show that this expectation is wrong. Using Hubble Space Telescope imaging of the host galaxies of long-duration gamma-ray bursts and core-collapse supernovae, we demonstrate that while the distribution of the supernovae in their hosts traces the blue light of young stars, the gamma-ray bursts are much more concentrated on the very brightest regions of their hosts. Furthermore, the host galaxies of the gamma-ray bursts are significantly fainter and more irregular than the hosts of the supernovae. Together these results suggest that long-duration gamma-ray bursts are associated with the very most massive stars and may be restricted to galaxies of limited chemical evolution. Our results directly imply that long-duration gamma-ray bursts are relatively rare in galaxies such as our own Milky Way.

Fruchter, A. S.; Levan, A. J.; Strolger, L.; Vreeswijk, P. M.; Bersier, D.; Burud, I.; Castro-Ceron, J. M.; Consclice, C.; Dahlen, T.; Strolger, L.

2005-01-01

484

Conference Summary: Three Dimensional Explosions  

E-print Network

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

J. Craig Wheeler

2004-01-15

485

Advances in Plastic Surgery  

PubMed Central

Recent progress in plastic surgery has been rapid and many new techniques have been developed. Reconstructive procedures have been advanced by a better understanding of the anatomy of the blood supply to skin and muscle, with the subsequent development of the use of axial flaps, musculocutaneous flaps and neurosensory flaps. Burn treatment has advanced greatly, making it possible to successfully treat larger and more complicated burns. The development of microsurgery has made possible free-flap transfer and replantation of amputated parts. Advances in surgical procedures on the hands include a realization that primary repair of lacerated tendons and nerves will give good results. Replacement joints have been developed that can be used in hands for joints destroyed by arthritis or trauma. Craniofacial surgery is a new field of endeavor in plastic surgery, involving new techniques that can be used to treat exophthalmos of Graves' disease and the facial deformities resulting from gigantism and acromegaly. Head and neck procedures have advanced, with the emphasis on immediate reconstruction using new flaps. Techniques for treating cleft lip and palate have been refined. Encouraging results have been reported in the treatment of nevus flammeus with argon lasers. In aesthetic surgical procedures, the aim is for safety and consistent long-lasting results. Improved understanding of the physiology and treatment of radionecrosis has evolved. PMID:7072237

McDonald, Harold D.; Vasconez, Luis O.

1982-01-01

486

Quantum plasticity and supersolidity  

NASA Astrophysics Data System (ADS)

We have discovered that, in the total absence of impurities, helium 4 crystals are anomalously soft [1]. In our opinion, this is a consequence of the quantum properties of their dislocation lines which are able to move macroscopic distances (typically a fraction of a millimeter) at high speed (several meters per second) as a response to very small applied stresses (one microbar). Moreover, this quantum plasticity appears to be closely related to another astonishing property of quantum crystals, namely their "supersolidity," that is the possible superflow of a fraction of the crystal mass through the rest which remains elastic, actually more rigid than in the normal state [2]. Very tiny traces of helium 3 impurities are sufficient to pin the dislocations below about 100 mK and destroy the quantum plasticity. By studying rotational and elastic properties of crystals with various qualities and variable helium 3 content, we are now checking that supersolidity is a consequence of matter flowing along dislocation lines but only if these dislocations are pinned by impurities. [4pt] [1] X. Rojas, A. Haziot, V. Bapst, H.J. Maris, and S. Balibar, Anomalous softening of helium 4 crystals, Phys. Rev. Lett. 105, 145302 (2010). [0pt] [2] S. Balibar, The enigma of supersolidity, Nature 464, 176 (2010).

Balibar, Sebastien

2011-03-01

487

Optogenetics and synaptic plasticity  

PubMed Central

The intricate and complex interaction between different populations of neurons in the brain has imposed limits on our ability to gain detailed understanding of synaptic transmission and its integration when employing classical electrophysiological approaches. Indeed, electrical field stimulation delivered via traditional microelectrodes does not permit the targeted, precise and selective control of neuronal activity amongst a varied population of neurons and their inputs (eg, cholinergic, dopaminergic or glutamatergic neurons). Recently established optogenetic techniques overcome these limitations allowing precise control of the target neuron populations, which is essential for the elucidation of the neural substrates underlying complex animal behaviors. Indeed, by introducing light-activated channels (ie, microbial opsin genes) into specific neuronal populations, optogenetics enables non-invasive optical control of specific neurons with milliseconds precision. These approaches can readily be applied to freely behaving live animals. Recently there is increased interests in utilizing optogenetics tools to understand synaptic plasticity and learning/memory. Here, we summarize recent progress in applying optogenetics in in the study of synaptic plasticity. PMID:24162508

Xie, Yu-feng; Jackson, Michael F; MacDonald, John F

2013-01-01

488

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

NASA Astrophysics Data System (ADS)

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

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

489

Multiscale modeling and synaptic plasticity.  

PubMed

Synaptic plasticity is a major convergence point for theory and computation, and the process of plasticity engages physiology, cell, and molecular biology. In its many manifestations, plasticity is at the hub of basic neuroscience questions about memory and development, as well as more medically themed questions of neural damage and recovery. As an important cellular locus of memory, synaptic plasticity has received a huge amount of experimental and theoretical attention. If computational models have tended to pick specific aspects of plasticity, such as STDP, and reduce them to an equation, some experimental studies are equally guilty of oversimplification each time they identify a new molecule and declare it to be the last word in plasticity and learning. Multiscale modeling begins with the acknowledgment that synaptic function spans many levels of signaling, and these are so tightly coupled that we risk losing essential features of plasticity if we focus exclusively on any one level. Despite the technical challenges and gaps in data for model specification, an increasing number of multiscale modeling studies have taken on key questions in plasticity. These have provided new insights, but importantly, they have opened new avenues for questioning. This review discusses a wide range of multiscale models in plasticity, including their technical landscape and their implications. PMID:24560151

Bhalla, Upinder S

2014-01-01

490

White matter plasticity in adulthood.  

PubMed

CNS white matter is subject to a novel form of neural plasticity which has been termed "myelin plasticity". It is well established that oligodendrocyte generation and the addition of new myelin internodes continue throughout normal adulthood. These new myelin internodes maybe required for the de novo myelination of previously unmyelinated axons, myelin sheath replacement, or even myelin remodeling. Each process could alter axonal conduction velocity, but to what end? We review the changes that occur within the white matter over the lifetime, the known regulators and mediators of white matter plasticity in the mature CNS, and the physiological role this plasticity may play in CNS function. PMID:24161723

Wang, S; Young, K M

2014-09-12

491

Americium behaviour in plastic vessels.  

PubMed

The adsorption of (241)Am dissolved in water in different plastic storage vessels was determined. Three different plastics were investigated with natural and distilled waters and the retention of (241)Am by these plastics was studied. The same was done by varying vessel agitation time, vessel agitation speed, surface/volume ratio of water in the vessels and water pH. Adsorptions were measured to be between 0% and 70%. The adsorption of (241)Am is minimized with no water agitation, with PET or PVC plastics, and by water acidification. PMID:20042341

Legarda, F; Herranz, M; Idoeta, R; Abelairas, A

2010-01-01

492

Cosmic Explosions in Three Dimensions  

NASA Astrophysics Data System (ADS)

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

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

2011-08-01

493

Cosmic Explosions in Three Dimensions  

NASA Astrophysics Data System (ADS)

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

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

2004-12-01

494

Time-domain terahertz spectroscopy and applications on drugs and explosives  

NASA Astrophysics Data System (ADS)

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

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

2008-03-01

495

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

PubMed

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

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

2004-02-15

496

46 CFR 109.559 - Explosives and radioactive materials.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Explosives and radioactive materials. 109.559 Section 109...Miscellaneous § 109.559 Explosives and radioactive materials. Except as authorized...charge, no person may use explosives or radioactive materials and equipment on a...

2011-10-01

497

46 CFR 109.559 - Explosives and radioactive materials.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Explosives and radioactive materials. 109.559 Section 109...Miscellaneous § 109.559 Explosives and radioactive materials. Except as authorized...charge, no person may use explosives or radioactive materials and equipment o