WorldWideScience

Sample records for bonded explosive pbx

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-01-01

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

  2. Initiation of preshocked high explosives PBX-9404, PBX-9502, PBX-9501, monitored with in-material magnetic gauging

    Energy Technology Data Exchange (ETDEWEB)

    Mulford, R.N.; Sheffield, S.A.; Alcon, R.R.

    1993-08-01

    Desensitization of explosives by preshocking is being studied using the well-supported plane shock waves generated by a gas gun. Evolution of the waves in the explosive is monitored using in-material multiple magnetic gauges to measure particle velocity in the lagrangian frame, over {approx} 3{mu}s of run. PBX-9404, PBX-9502 have been studied, at pressures up to 10.5 GPa. A substantial extension of the run to detonation is observed in PBX-9404, with the run beginning approximately at the end of the preshocked region. A reactive wave is observed while the preshock persists in both PBX-9404 and PBX-9501, but evidently does not contribute to the detonation wave or shorten the run to detonation. PBX-9502 is inert at pressures accessible with the gas gun, but serves to clarify the progress of multiple shocks over the off-Hugoniot EOS surface and the shock dynamics of wave coalescence.

  3. Analysis of xRAGE and flag high explosive burn models with PBX 9404 cylinder tests

    Energy Technology Data Exchange (ETDEWEB)

    Harrier, Danielle [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Andersen, Kyle Richard [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-05

    High explosives are energetic materials that release their chemical energy in a short interval of time. They are able to generate extreme heat and pressure by a shock driven chemical decomposition reaction, which makes them valuable tools that must be understood. This study investigated the accuracy and performance of two Los Alamos National Laboratory hydrodynamic codes, which are used to determine the behavior of explosives within a variety of systems: xRAGE which utilizes an Eulerian mesh, and FLAG with utilizes a Lagrangian mesh. Various programmed and reactive burn models within both codes were tested using a copper cylinder expansion test. The test was based on a recent experimental setup which contained the plastic bonded explosive PBX 9404. Detonation velocity versus time curves for this explosive were obtained using Photon Doppler Velocimetry (PDV). The modeled results from each of the burn models tested were then compared to one another and to the experimental results. This study validate

  4. Autonomous characterization of plastic-bonded explosives

    Science.gov (United States)

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

    2006-08-01

    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.

  5. Highly Shocked Polymer Bonded Explosives at a Nonplanar Interface: Hot-Spot Formation Leading to Detonation

    OpenAIRE

    An, Qi; Goddard, William A.; Zybin, Sergey V.; Jaramillo-Botero, Andres; Zhou, Tingting

    2013-01-01

    We report reactive molecular dynamics simulations using the ReaxFF reactive force field to examine shock-induced hot-spot formation followed by detonation initiation in realistic (2.7 million atoms) models of polymer bonded explosives (PBX) with nonplanar interfaces. We considered here two energetic materials (EMs) pentaerythritol tetranitrate (PETN), a common EM for PBX, and silicon pentaerythritol tetranitrate (Si-PETN), which is so extremely sensitive that it has not been possible to chara...

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

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, D. M., LLNL

    1998-04-23

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

  7. Shock initiation of the TATB based explosive PBX 9502 heated to ~ 76∘C

    Science.gov (United States)

    Gustavsen, Richard; Gehr, Russell; Bucholtz, Scott; Pacheco, Adam; Bartram, Brian

    2015-06-01

    Recently we reported on shock initiation of PBX 9502 (95 wt.% tri-amino-trinitro-benzene, 5 wt.% Kel-F800 binder) cooled to -55°C and to 77K Shock waves were generated by gas-gun driven plate impacts and reactive flow in the cooled PBX 9502 was measured with embedded electromagnetic gauges. Here we use similar methods to warm the explosive to ~ 76°C. The explosive sample is heated by warm air flowing through channels in an aluminum sample mounting plate and a copper tubing coil surrounding the sample. Temperature in the sample is monitored using six type-E thermocouples. Results show increased shock sensitivity; time and distance to detonation onset vs. initial shock pressure are shorter than when the sample is initially at ambient temperature. Our results are consistent with those reported by Dallman & Wackerle. Particle velocity wave profiles were also obtained during the shock-to-detonation transition and will be presented.

  8. Complete EOS for PBX 9502

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph S [Los Alamos National Laboratory

    2009-10-08

    PBX 9502 is an insensitive plastic-bonded explosive based on triamino-trinitrobenzene (TATB). A complete equation of state (EOS) is constructed for unreacted PBX 9502 suitable for reactive burn models, i.e., high pressure regime in which material strength is unimportant. The PBX EOS is composed of two parts: a complete EOS for TATB and a porosity model which allows for variations in the initial PBX density. The TATB EOS is based on a cold curve and a thermal model for lattice vibrations. The heat capacity, and hence thermal model, is determined by the vibrational spectrum from Raman scattering. The cold curve is calibrated to diamond anvil cell data for isothermal compression using a two-piece Keane fitting form. Hugoniot data for PBX 9502 is used as a consistency check.

  9. Low amplitude insult project: PBX 9501 high explosive violent reaction experiments

    Energy Technology Data Exchange (ETDEWEB)

    Idar, D.J.; Lucht, R.A.; Straight, J.W.; Scammon, R.J.; Browning, R.V.; Middleditch, J.; Dienes, J.K.; Skidmore, C.B.; Buntain, G.A.

    1998-12-31

    The Modified Steven test geometry has been used with several different target designs to investigate the mechanical loading behavior of PBX 9501 to a low velocity impact. A 2 kg. mild steel spigot projectile is launched via a new powder driven gun design, from {approximately} 20 to 105 m/s, at lightly confined, steel targets. Brief descriptions of the gun design and operation are given. The threshold velocity to reaction for various target designs, different PBX 9501 lots, and different high explosive (HE) thicknesses are reported and compared. Various diagnostics have been employed to evaluate the pressure profile and timing, and target strain behavior relative to projectile impact. The violence of reaction, as measured by both passive and active techniques, is reported relative to a steady state detonation in PBX 9501. Experimental results suggest slightly different ignition mechanisms dominate based on (HE) thickness, resulting in delayed reactions from {approximately} 0.2- to 2.8-ms after impact. Post-test analyses of the PBX 9501 are briefly summarized.

  10. SHOCK INITIATION EXPERIMENTS ON PBX 9501 EXPLOSIVE AT PRESSURES BELOW 3 GPa WITH ASSOCIATED IGNITION AND GROWTH MODELING

    Energy Technology Data Exchange (ETDEWEB)

    Chidester, S K; Thompson, D G; Vandersall, K S; Idar, D J; Tarver, C M; Garcia, F; Urtiew, P A

    2007-06-13

    Shock initiation experiments on the explosive PBX 9501 (95% HMX, 2.5% estane, and 2.5% nitroplasticizer by weight) were performed at pressures below 3 GPa to obtain in-situ pressure gauge data, run-distance-to-detonation thresholds, and Ignition and Growth modeling parameters. Propellant driven gas guns (101 mm and 155 mm) were utilized to initiate the PBX 9501 explosive with manganin piezoresistive pressure gauge packages placed between sample slices. The run-distance-to-detonation points on the Pop-plot for these experiments showed agreement with previously published data and Ignition and Growth modeling parameters were obtained with a good fit to the experimental data. This parameter set will allow accurate code predictions to be calculated for safety scenarios in the low-pressure regime (below 3 GPa) involving PBX 9501 explosive.

  11. Inhibition of Hotspot Formation in Polymer Bonded Explosives Using an Interface Matching Low Density Polymer Coating at the Polymer–Explosive Interface

    OpenAIRE

    An, Qi; Goddard, William A.; Zybin, Sergey V.; Luo, Sheng-Nian

    2014-01-01

    In order to elucidate how shocks in heterogeneous materials affect decomposition and reactive processes, we used the ReaxFF reactive force field in reactive molecules dynamics (RMD) simulations of the effects of strong shocks (2.5 and 3.5 km/s) on a prototype polymer bonded explosive (PBX) consisting of cyclotrimethylene trinitramine (RDX) bonded to hydroxyl-terminated polybutadiene (HTPB). We showed earlier that shock propagation from the high density RDX to the low density polymer (RDX → Po...

  12. ONE-DIMENSIONAL TIME TO EXPLOSION (THERMAL SENSITIVITY) TESTS ON PETN, PBX-9407, LX-10, AND LX-17

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Peter C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Strout, Steve [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McClelland, Matthew [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ellsworth, Fred Ellsworth [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-01-28

    Incidents caused by fire and combat operations can heat energetic materials that may lead to thermal explosion and result in structural damage and casualty. Some explosives may thermally explode at fairly low temperatures (< 100 C) and the violence from thermal explosion may cause a significant damage. Thus it is important to understand the response of energetic materials to thermal insults. The One Dimensional Time to Explosion (ODTX) system at the Lawrence Livermore National Laboratory has been used for decades to measure times to thermal explosion, threshold thermal explosion temperature, and determine the kinetic parameters of thermal decomposition of energetic materials. Samples of different configurations (pressed part, powder, paste, and liquid) can be tested in the system. The ODTX testing can also provide useful data for assessing the thermal explosion violence of energetic materials. This report summarizes the results of our recent ODTX experiments on PETN powder, PBX-9407 pressed part, LX-10 pressed part, LX-17 pressed part and compares the test data that were obtained decades ago with the older version of ODTX system. Test results show the thermal sensitivity of various materials tested in the following order: PETN> PBX-9407 > LX-10 > LX-17.

  13. Studies on Physico-Mechanical and Explosive Characteristics of RDX/HMX-Based Castable Plastic-Bonded Explosives

    Directory of Open Access Journals (Sweden)

    J. S. Gharia

    1998-01-01

    Full Text Available Conventional cast explosives (RDX/TNT have major drawbacks of poor mechanical properties,shrinkages and higher sensitivity .These properties can be improved by applying plastic bindersystems. The plastic-bonded explosive (PBX is a composite material in which solid explosive particles are dispersed in a polymer matrix. The present paper describes the development of anitramine/hydroxy-terminated polybutadiene (HTPB-based castable PBX. The PBXs were processed as per standard procedures. Bimodal/trimodal particle size system was selected to reach asolid loading of 88 wt per cent. High solid loading was made possible through proper combination ofcoarse/fine ratio of solid ingredients, which was based on a number of tap density experiments.Processability of the binder system was studied by using various wetting agents as well as by selectingbinder/plasticizer ratios. Mechanical properties of the PBXs were enhanced by different crosslinkingagents. The explosive properties ofPBXs including detonation velocity , processability and sensitivityto different types of stimuli, were studied. The results show that PBXs can be manufactured withdetonation properties better than those of composition B/octol with the added advantages of superiorthermal and sensitivity characteristics.

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

    Science.gov (United States)

    Bolme, C A; Ramos, K J

    2013-08-01

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

  15. The effects of Gamma radiation on a PBX containing TATB and the fluoropolymer FK-800

    OpenAIRE

    Connors, S C

    2014-01-01

    The polymer bonded explosive TCV is analogous to PBX compositions used in some nuclear weapons where the PBX will be exposed to high energy ionising gamma radiation. It is therefore important to study how gamma radiation affects the mechanical and chemical properties of the PBX. In this study 60Co was used to irradiate samples of the TCV, its FK-800 binder and TATB explosive filler, at 37.5 °C, to total doses up to 200 kGy in air and under vacuum. Post irradiation analysis consisted of mec...

  16. Deformation and Failure of Polymer Bonded Explosives

    Institute of Scientific and Technical Information of China (English)

    陈鹏万; 黄风雷; 丁雁生

    2004-01-01

    The deformation and failure of pressed polymer bonded explosives under different types of loads including tension, compression and low velocity impact are presented. Brazilian test is used to study the tensile properties. The microstructure of polymer bonded explosives and its evolution are studied by use of scanning electronic microscopy and polarized light microscopy. Polishing techniques have been developed to prepare samples for microscopic examination. The failure mechanisms of polymer bonded explosives under different loads are analyzed. The results show that interfacial debonding is the predominant failure mode in quasi-static tension, while extensive crystal fractures are induced in compression. With the increase of strain rate, more crystal fractures occur. Low velocity impact also induces extensive crystal fractures.

  17. Dynamic Mechanical Properties and Constitutive Relation of an Aluminized Polymer Bonded Explosive at Low Temperatures

    Directory of Open Access Journals (Sweden)

    Yuliang Lin

    2014-01-01

    Full Text Available Polymer bonded explosives (PBXs are widely used as energetic fillings in various warheads, which maybe are utilized under extreme environments, such as low or high temperatures. In this paper, the dynamic response of an aluminized polymer bonded explosive was tested at a range of temperatures from −55°C to −2°C and a fixed loading strain rate (~700 s−1 with the split Hopkinson pressure bar (SHPB. The PBX tested is aluminized, which contains 76 wt% RDX, 20 wt% aluminum powder, and 4 wt% polymer binder, respectively. The results show that the effect of temperature on the strength of the PBX is obvious at the tested strain rates. Based on the experimental results and prophase studies, a constitutive model was obtained, in which the effect of temperature and strain rate were considered. The modeling curves fit well with the experimental results, not only at low temperature under 0°C, but also at room temperature (20°C. The model may be used to predict the dynamic performances of the PBXs in various environments.

  18. PBX炸药细观结构冲击点火的二维数值模拟%Two-dimensional Mesoscale Simulation of Shock Ignition in PBX Explosives

    Institute of Scientific and Technical Information of China (English)

    刘群; 陈朗; 伍俊英; 王晨

    2011-01-01

    为了研究冲击加载下非均质炸药的点火机理,对PBX炸药细观结构在冲击加载下的响应过程进行了二维数值模拟.首先对炸药颗粒的压制过程进行数值模拟,获得PBX炸药的细观结构模型.然后对炸药冲击点火进行数值模拟计算,考虑了热力耦合作用和炸药自热反应,分析了炸药颗粒尺寸、密度和黏结剂对炸药冲击点火的影响.结果表明,冲击作用下PBX炸药点火点出现在炸药颗粒与黏结剂界面处;炸药颗粒尺寸较小时,PBX炸药点火的临界压力较大;随着PBX炸药密度的增加,临界点火压力逐渐增大;黏结剂能够衰减冲击波对炸药颗粒的压缩作用,黏结剂增多,PBX炸药的临界点火压力提高.%To investigate the mechanism of shock ignition in heterogeneous explosives, two-dimensional mesoscale simulation of PBX explosives under shock loading was conducted. Through simulation of explosive particles press-ing,the mesoscale structure of PBX was obtained. Then the shock ignition of PBX explosives was calculated,and the coupled thermo-mechanics and self-heating reaction were considered, and the influence of explosive density, particle size and binder content on shock ignition were analyzed. The results show that hot spots focus on the interface be-tween explosive particles and binder. The critical pressure to ignite explosives in small particle size is higher than that in large particle size. The critical pressure to ignite explosives in low density is higher than that of explosives in high density. In addition,binders play an important role in attenuating shock intensity on explosive particles,and PBX ex-plosives in more binder content are more insensitive than those in less binder content.

  19. NPT Ensemble MD Simulation Investigation on the Mechanical Properties of HMX/F2311 Polymer-bonded Explosive

    Institute of Scientific and Technical Information of China (English)

    XIAO Ji-Jun; ZHANG Hang; HUANG Hui; LI Jing-Shang; ZHU Wei; XIAO He-Ming

    2008-01-01

    Molecular dynamics simulation was applied to investigate the mechanical properties of β-octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine(β-HMX)-based polymer-bonded explosive(PBX)with F2311 fluorine rubber(It is produced by copolymerization of vinylidene difluoride and chlorotrifluoroethylene in the molar ratio 1 over 1).The elastic constants for β-HMX crystal and the HMX-based PBX were computed using a static elastic constant analysis method,and the engineering moduli and Poisson ratios were derived by Reuss average.Based on the value of Cauchy pressure and the ratio of bulk modulus to shear modulus,it is indicated that the ductibility of crystalline HMX can be effectively improved by blending the polymer in a small amount.

  20. Pressure Wave Measurements from Thermal Cook-Off of an HMX Based High Explosive PBX 9501

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, F; Forbes, J W; Tarver, C M; Urtiew, P A; Greenwood, D W; Vandersall, K S

    2001-05-31

    A better understanding of thermal cook-off is important for safe handling and storing explosive devices. A number of safety issues exist about what occurs when a cased explosive thermally cooks off. For example, violence of the events as a function of confinement are important for predictions of collateral damage. This paper demonstrates how adjacent materials can be gauged to measure the resulting pressure wave and how this wave propagates in this adjacent material. The output pulse from the thermal cook-off explosive containing fixture is of obvious interest for assessing many scenarios.

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

    Energy Technology Data Exchange (ETDEWEB)

    Gagliardi, F J; Cunningham, B J

    2008-03-13

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

  2. Preliminary results for explosion bonding of beryllium to copper

    Energy Technology Data Exchange (ETDEWEB)

    Butler, D.J. [Northwest Technical Industries, Inc., Sequim, WA (United States); Dombrowski, D.E. [Brush Wellman, Inc., Cleveland, OH (United States)

    1995-09-01

    This program was undertaken to determine if explosive bonding is a viable technique for joining beryllium to copper substrates. The effort was a cursory attempt at trying to solve some of the problems associated with explosive bonding beryllium and should not be considered a comprehensive research effort. There are two issues that this program addressed. Can beryllium be explosive bonded to copper substrates and can the bonding take place without shattering the beryllium? Thirteen different explosive bonding iterations were completed using various thicknesses of beryllium that were manufactured with three different techniques.

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

    Energy Technology Data Exchange (ETDEWEB)

    Reaugh, J E

    2009-05-07

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

  4. Molecular dynamic simulations on the structures and properties of epsilon-CL-20(0 0 1)/F 2314 PBX.

    Science.gov (United States)

    Xu, Xiaojuan; Xiao, Jijun; Huang, Hui; Li, Jinshan; Xiao, Heming

    2010-03-15

    Molecular dynamical (MD) simulations with the COMPASS force field were employed to investigate the influences of temperature (T), the concentration of F(2314) binder (W%), and crystal defects on the mechanical properties, binding energy (E(bind)), and detonation properties of epsilon-CL-20(001)/F(2314) PBX (polymer bonded explosives). T was found to have some influences on the mechanical properties, and the PBX at 298 K was considered with better mechanical properties. By radial distribution function g(r) analysis the three types of hydrogen bonds, H...O, H...F, and H...Cl were predicted as the main interaction formats between F(2314) and epsilon-CL-20, and the strength of these interactions changed with temperature changing. The isotropic properties of the PBX increased with W% increasing, but each modulus and E(bind) did not monotonously vary with W% increasing. The detonation properties of the PBX decreased with the increasing W%, and the PBX with 4.69% F(2314) was regarded with good detonation properties. The existence of crystal defects (vacancy or adulteration) might increase the elasticity but destabilize the system to some extent, and the mechanical properties of PBX were chiefly determined by the main body explosive. The above information was thought guidable for practical formulation design of PBX. PMID:19954888

  5. The Equation of State of PBX 9502

    Science.gov (United States)

    Aslam, Tariq

    Reactive flow modeling of high explosives (HEs) requires accurate equation of states (EOS) for both the HE's reactants and products. The Wescott-Stewart-Davis ``wide-ranging EOS'' model will be examined. A procedure for calibrating both the reactants and products for this EOS will be presented. Several thermodynamic pathways will be explored for the plastic bonded HE PBX 9502. These include: isothermal compression, isentropic compression, single and multiple shock compression, isobaric thermal expansion, adiabatic expansion of the products and the overdriven detonation state. Data from several different experimental techniques are employed to constrain model parameters. Validation tests of the model EOS will also be presented.

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

    Energy Technology Data Exchange (ETDEWEB)

    B. Olinger

    2005-04-15

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

  7. Energetic materials: crystallization, characterization and insensitive plastic bonded explosives

    NARCIS (Netherlands)

    Heijden, A.E.D.M. van der; Creyghton, Y.L.M.; Marino, E.; Bouma, R.H.B.; Scholtes, G.J.H.G.; Duvalois, W.; Roelands, C.P.M.

    2008-01-01

    The product quality of energetic materials is predominantly determined by the crystallization process applied to produce these materials. It has been demonstrated in the past that the higher the product quality of the solid energetic ingredients, the less sensitive a plastic bonded explosive contain

  8. Ultrasonic Evaluation of the Impact Damage of Polymer Bonded Explosives

    Institute of Scientific and Technical Information of China (English)

    陈鹏万; 戴开达; 黄风雷; 丁雁生

    2004-01-01

    The damage properties of polymer bonded explosives under dynamic loading were studied by using ultrasonic evaluation. Explosive samples were damaged by a low-velocity gas gun at different impact velocities. Ultrasonic examination was carried out with a pulse through-transmission method. Spectra analyses were carried out by using fast Fourier transform. Characteristic ultrasonic parameters, including ultrasonic velocities, attenuation coefficients, spectra area and master frequency, were obtained. The correlation between the impact damage and ultrasonic parameters was analyzed. A damage coefficient D was defined by considering a combination of ultrasonic velocity and amplitude. The results show that ultrasonic parameters can be used to quantitatively assess the damage extent in impacted plastic bonded explosives.

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

    Science.gov (United States)

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

    2015-09-01

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

  10. Ranchero Armature Test LA-19.4-CT-3: PBX-9501 Explosive with no smoothing layer. Firing point 88, 9/16/13

    Energy Technology Data Exchange (ETDEWEB)

    Glover, Brian B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Goforth, James H. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rae, Philip John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dickson, Peter [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Briggs, Matthew E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Marr-Lyon, Mark [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hare, Steven John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Herrera, Dennis Harold [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Watt, Robert Gregory [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rousculp, Christopher L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-11-13

    LA-19.4-CT-3 (CT-3) was the third camera test in a series beginning in 1/11, which diagnose the performance of 6 mm thick, 6061 T-0 Al Ranchero armatures. [The test LA-43-CT-2 (CT-2) is described in LA-UR-14-21983.] The goal of CT-3 was to verify that PBX-9501, with 18 mm point spacing and no smoothing layer, could be used for Ranchero generator armatures in place of PBXN-110, which had been used in all previous Ranchero applications. CT-1 and CT-2 both had 43 cm long slapper detonator systems imbedded in the cast PBXN-110 explosive, but manufacturing a charge for a similar 9501 test was not cost effective. Instead, a single cylinder of 9501, 19.368 cm long and 15.494 cm (6.100”)in diameter, had a groove machined to accommodate a row of 11 SE-1 detonators with 18 mm point spacing along the mid-plane of the cylinder. The expansion of the armature looks like a slapper assembly along almost ½ of the circumference, and provides adequate proof of concept. Removing the smoother from PBXN-110-driven armatures increased the armature velocity from 3.1 mm/μs to 3.3 mm/μs, as seen in CT-2, and the velocity measured on CT-3 increased to 3.8 mm/μs. In addition, the camera records show that the surface of the armature is smooth enough, and free from ruptures for an expansion of greater that 2X. The advantage of using 9501 is that it precludes concerns about blow-outs seen when bubbles are left in the cast material, and gives extra velocity. The disadvantage is that the machined explosives are more expensive.

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

    Science.gov (United States)

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

    2009-06-01

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

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

    Science.gov (United States)

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

    2009-06-01

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

  13. SMIS PBX-9502 Test Report

    Energy Technology Data Exchange (ETDEWEB)

    Marr-Lyon, Mark [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sandoval, Thomas D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Herrera, Dennis H. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-04-11

    Two impact experiments in the Specific Munitions Impact Scenario (SMIS) configuration [1{3] were performed on September 3 and 4, 2013 at Lower Slobbovia ring site. Targets of the high explosive PBX-9502 were impacted with 1/2-inch diameter low-carbon steel spheres red from a 30-mm powder gun at velocities of approximately 2.5 km/s. In one experiment the target was cased in a steel cylinder with steel end plates, and in the second the target was cased in a plastic cylinder with a thin steel front cover plate and a thick steel rear plate. In neither experiment did the PBX-9502 detonate, though some material reacted in the impact

  14. Mechanical and Explosive Properties of Plastic Bonded Explosives Based on Mixture of HMX and TATB

    Directory of Open Access Journals (Sweden)

    Arjun Singh

    2013-12-01

    Full Text Available This paper describes formulation of plastic bonded explosives (PBXs compositions based on 2,4,6- triamino-1,3,5-trinitrobenzene (TATB, Octahydro l,3,5,7-tetranitro- 1,3,5,7-tetrazocine (HMX by varying their relative amounts with Viton A as polymeric binder by slurry coating technique. These PBXs compositions are studied for mechanical and detonic properties. It has been observed that sensitivity and explosive performance of PBXs based on mixture of HMX and TATB were varied over a wide considerable range by varying relative amounts of TATB and HMX. The detonation study revealed there was increased in velocity of detonation (VOD and detonation pressure with increasing amount of HMX from 10-80 % by weight. The sensitivity test results exhibited that insensitivity to impact for PBXs compositions was found to decrease with increasing HMX amount.  Friction sensitivity study showed that no reactions were observed upto 36 kg load for PBXs compositions namely HT6030, HT5040, HT4050, HT3060, HT2070 and HT1080. The compressive strength of these PBXs compositions was found within the range of 9-11 MPa.Defence Science Journal, 2013, 63(6, pp.622-629, DOI:http://dx.doi.org/10.14429/dsj.63.5764

  15. Sensitivity of once-shocked, weathered high explosives

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-07-01

    Effects caused by stimulating once-shocked, weathered high explosives (OSW-HE) are investigated. The sensitivity of OSW-HE to mechanical stimuli was determined using standard industry tests. Some initial results are given. Pieces of OSW-HE were collected from active and inactive firing sites and from an area surrounding a drop tower at Los Alamos where skid and spigot tests were done. Samples evaluated were cast explosives or plastic bonded explosive (PBX) formulations containing cyclotrimethylenetrinitramine (RDX), cyclotetramethylene tetranitramine (HMX), 2,4,6-trinitrotoluene (TNT), mock or inert HE [tris(beta-chloroethyl)phosphate (CEF)], barium nitrate, cyanuric acid, talc, and Kel-F. Once-shocked, weathered LX-10 Livermore explosive [HMX/Viton A, (95/5 wt %)], PBX 9011 [HMX/Estane, (90/10 wt %)], PBX 9404 [HMX/nitrocellulose, tris(beta-chloroethyl) phosphate, (94/3/3 wt %)], Composition B or cyclotol (TNT/RDX explosives), and PBX 9007 (90% RDX, 9.1% styrene, 0.5% dioctyl phthalate, and 0.45 resin) were subjected to the hammer test, the drop-weight impact sensitivity test, differential thermal analysis (DTA), the spark test, the Henkin`s critical temperature test, and the flame test. Samples were subjected to remote, wet cutting and drilling; remote, liquid-nitrogen-cooled grinding and crushing; and scanning electron microscope (SEM) surface analyses for morphological changes.

  16. Development of an Explosive Bonding Process for Producing High Strength Bonds between Niobium and 6061-T651 Aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, T A; Elmer, J W; Brasher, D; Butler, D; Riddle, R

    2005-09-23

    An explosive bonding procedure for joining 9.5 mm thick niobium plate to 203 mm thick 6061-T651 Al plate has been developed in order to maximize the bond tensile and impact strengths and the amount of bonded material across the surface of the plate. This procedure improves upon previous efforts, in which the 9.5 mm thick niobium plate is bonded directly to 6061-T4 Al plate. In this improved procedure, thin Nb and Al interlayers are explosively clad between the thicker niobium and aluminum plates. Bonds produced using these optimized parameters display a tensile strength of approximately 255 MPa and an impact strength per unit area of approximately 0.148 J/mm{sup 2}. Specialized mechanical testing geometries and procedures are required to measure these bond properties because of the unique bond geometry. In order to ensure that differences in the thermal expansion coefficients of aluminum and niobium do not adversely affect the bond strength, the effects of thermal cycling at temperatures between -22 C and 45 C on the mechanical properties of these bonds have also been investigated by testing samples in both the as-received and thermal cycled conditions. Based on the results obtained from this series of mechanical tests, thermal cycling is shown to have no adverse effect on the resulting tensile and impact strengths of the bonds produced using the optimized bonding parameters.

  17. Modeling the mechanical response of PBX 9501

    Energy Technology Data Exchange (ETDEWEB)

    Ragaswamy, Partha [Los Alamos National Laboratory; Lewis, Matthew W [Los Alamos National Laboratory; Liu, Cheng [Los Alamos National Laboratory; Thompson, Darla G [Los Alamos National Laboratory

    2010-01-01

    An engineering overview of the mechanical response of Plastic-Bonded eXplosives (PBXs), specifically PBX 9501, will be provided with emphasis on observed mechanisms associated with different types of mechanical testing. Mechanical tests in the form of uniaxial tension, compression, cyclic loading, creep (compression and tension), and Hopkinson bar show strain rate and temperature dependence. A range of mechanical behavior is observed which includes small strain recoverable response in the form of viscoelasticity; change in stiffness and softening beyond peak strength due to damage in the form microcracks, debonding, void formation and the growth of existing voids; inelastic response in the form of irrecoverable strain as shown in cyclic tests, and viscoelastic creep combined with plastic response as demonstrated in creep and recovery tests. The main focus of this paper is to elucidate the challenges and issues involved in modeling the mechanical behavior of PBXs for simulating thermo-mechanical responses in engineering components. Examples of validation of a constitutive material model based on a few of the observed mechanisms will be demonstrated against three point bending, split Hopkinson pressure bar and Brazilian disk geometry.

  18. A study of the overdriven behaviors of PBX 9501 and PBX 9502

    Energy Technology Data Exchange (ETDEWEB)

    Tang, P.K.

    1998-12-31

    The author presents the Hugoniot pressure and sound speed data in the overdriven regime for both PBX 9501 and PBX 9502. The overdriven release experiments are also given. The failure of the standard Jones-Wilkins-Lee equation of state in modeling both the Hugoniot data and the overdriven release experiments for both high explosives are identified and remedy is made by including additional terms to steepen the slope of the Hugoniot in the high pressure regime. However, an anomaly presented itself as a kink in the release wave of PBX 9502 is observed. A careful examination of the Hugoniot data indicates similar behavior. A possible explanation is suggested for this peculiarity to the phase transition of carbon in the products.

  19. Transient Response of Partially-Bonded Sandwich Plates Subject to Underwater Explosions

    Directory of Open Access Journals (Sweden)

    Zhanke Liu

    2010-01-01

    Full Text Available This paper investigated the influence of interfacial bonding on the transient response of sandwich plates subject to underwater explosions. It was found that un-bonded sandwich plates receive lower impact energy, and are able to dissipate more energy through plastic deformation of the foam core, than perfectly bonded plates. Consequently, interfacial de-bonding leads to lower net energy transfer from the explosion to the target structure although it also increases the structural deformation due to stiffness reduction. Parametric studies showed that the advantage (diminishing of net energy transfer is more significant than the disadvantage (magnification of the interface deflection. Thus, interfacial de-bonding through active/passive mechanisms may be beneficial for blast-resistant designs.

  20. Bonding Interface and Bending Deformation of Al/316LSS Clad Metal Prepared by Explosive Welding

    Science.gov (United States)

    Guo, Xunzhong; Fan, Minyu; Wang, Liuan; Ma, Fuye

    2016-06-01

    The morphology, elemental distribution, and phase analysis of the bonding interface were investigated by means of SEM, EDS, and XRD to evaluate the interface bonding properties of Al/316LSS clad metal prepared by explosive welding method. Furthermore, the micro-hardness and bending properties were also investigated. The results indicated that the linear and wavy bonding interfaces coexisted and intermetallic phases were present in the local interfacial zone. Moreover, the micro-hardness value at the bonding interface with intermetallic phases was higher than that at the interface without any intermetallic phases. In addition, bulk metal compounds could easily lead to the generation of micro-cracks during the bending forming process.

  1. CTH simulation of PBX-9501 Taylor tests /

    Energy Technology Data Exchange (ETDEWEB)

    Koby, Joseph R.

    2011-09-01

    During March-May 2011, multiple Taylor impact tests were conducted at LANL, examining the behavior of PBXN-9 and PBX-9501 under rapid loading. Subsequently, a computational hydrodynamics code (CTH) model was developed to mimic the deformation behavior observed in these impact tests with PBX-9501 would likely initiate upon impact. Also examined was whether an inert slud behind the explosive would lead to initiation at lower, more easily attainable velocities. The simplified model used here showed a minimum velocity for ignition of 530 m/s which was unchanged by the addition of a plastic slud behind the sample. The use of a lead slug did lower the minimum velocity to 460 m/s. These values are likely more qualitative at this point because multiple simplifications are currently used in the materials properties and test geometry. The results do show that this approach is capable of determining ignition due to Taylor impact.

  2. Methods and system for controlled laser-driven explosive bonding

    Energy Technology Data Exchange (ETDEWEB)

    Rubenchik, Alexander M.; Farmer, Joseph C.; Hackel, Lloyd; Rankin, Jon

    2015-11-19

    A technique for bonding two dissimilar materials includes positioning a second material over a first material at an oblique angle and applying a tamping layer over the second martial. A laser beam is directed at the second material that generates a plasma at the location of impact on the second material. The plasma generates pressure that accelerates a portion of the second material to a very high velocity and towards the first material. The second material impacts the first material causing bonding of the two materials.

  3. Low-temperature oxidative degradation of PBX 9501 and its components determined via molecular weight analysis of the poly [ester urethane] binder

    Energy Technology Data Exchange (ETDEWEB)

    Kress, Joel D [Los Alamos National Laboratory

    2008-01-01

    The results of following the oxidative degradation of a plastic-bonded explosive (PBX 9501) are reported. Into over 1100 sealed containers were placed samples of PBX 9501 and combinations of its components and aged at relatively low temperatures to induce oxidative degradation of the samples. One of the components of the explosive is a poly(ester urethane) polymer and the oxidative degradation of the samples were following by measuring the molecular weight change of the polymer by gel permeation chromatography (coupled with both differential refractive index and multiangle laser light scattering detectors). Multiple temperatures between 40 and 64 {sup o}C were used to accelerate the aging of the samples. Interesting induction period behavior, along with both molecular weight increasing (crosslinking) and decreasing (chain scissioning) processes, were found at these relatively mild conditions. The molecular weight growth rates were fit to a random crosslinking model for all the combinations of components. The fit rate coefficients show Arrhenius behavior and activation energies and frequency factors were obtained. The kinetics of molecular weight growth shows a compensatory effect between the Arrhenius prefactors and activation energies, suggesting a common degradation process between PBX 9501 and the various combinations of its constituents. An oxidative chemical mechanism of the polymer is postulated, consistent with previous experimental results, that involves a competition between urethane radical crosslinking and carbonyl formation.

  4. Study on Thermal Decomposition Characteristics and Sensitivities of Nano-RDX Based PBX%纳米RDX基PBX混合炸药的热分解特性和感度研究❋

    Institute of Scientific and Technical Information of China (English)

    乔羽; 刘杰; 肖磊; 郝嘎子; 高寒; 曾江保; 姜炜

    2016-01-01

    Nano-RDX based polymer bonded explosive ( PBX) was prepared using solution-water slurry method by controlling the reaction conditions such as ratio of water to material, reaction temperature and stirring speed. Thermal de-composition characteristics of nano-RDX based PBX were analyzed by a TG/DSC simultaneous thermal analyser,and its im-pact sensitivity and friction sensitivity were tested according to GJB772A—1997. Results show that, compared to those of micron-RDX based PBX, DTG peak temperature of nano-RDX based PBX shifts 0. 6 ℃ upwards, and its activation energy decreases by 2. 5 kJ/mol. Impact sensitivity H50 of nano-RDX based PBX is 46. 3 cm, decreasing by 55. 4% comparing with micron-RDX based PBX, H50 of which is only 29. 8 cm. Friction sensitivity of nano-RDX based PBX has a decrease of 21. 1% compared to micron-RDX based PBX.%采用溶液-水悬浮法,通过控制料液质量比、包覆温度、搅拌速度等工艺参数制备了纳米RDX基PBXº使用TG/DSC同步热分析仪研究其热分解特性,并依据GJB 772A—1997分别对其撞击感度和摩擦感度进行了测试º结果表明:与微米RDX基PBX相比,纳米RDX基PBX的DTG峰温提前约0.6℃,活化能降低约2.5 kJ/mol;纳米RDX基PBX撞击感度H50为46.3 cm,微米RDX基PBX H50为29.8 cm,相对降低55.4%;纳米RDX基PBX摩擦感度比微米RDX基PBX相对降低21.1%º

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-09-01

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

  6. Deflagration Behavior of PBX 9501 at Elevated Temperature and Pressure

    Energy Technology Data Exchange (ETDEWEB)

    Maienschein, J L; Koerner, J G

    2008-04-15

    We report the deflagration behavior of PBX 9501 at pressures up to 300 MPa and temperatures of 150-180 C where the sample has been held at the test temperature for several hours before ignition. The purpose is to determine the effect on the deflagration behavior of material damage caused by prolonged exposure to high temperature. This conditioning is similar to that experienced by an explosive while it being heated to eventual explosion. The results are made more complicated by the presence of a significant thermal gradient along the sample during the temperature ramp and soak. Three major conclusions are: the presence of nitroplasticizer makes PBX 9501 more thermally sensitive than LX-04 with an inert Viton binder; the deflagration behavior of PBX 9501 is more extreme and more inconsistent than that of LX-04; and something in PBX 9501 causes thermal damage to 'heal' as the deflagration proceeds, resulting in a decelerating deflagration front as it travels along the sample.

  7. Propagation of Reactions in Thermally-damaged PBX-9501

    Energy Technology Data Exchange (ETDEWEB)

    Tringe, J W; Glascoe, E A; Kercher, J R; Willey, T M; Springer, H K; Greenwood, D W; Molitoris, J D; Smilowitz, L; Henson, B F; Maienschein, J L

    2010-03-05

    A thermally-initiated explosion in PBX-9501 (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) is observed in situ by flash x-ray imaging, and modeled with the LLNL multi-physics arbitrary-Lagrangian-Eulerian code ALE3D. The containment vessel deformation provides a useful estimate of the reaction pressure at the time of the explosion, which we calculate to be in the range 0.8-1.4 GPa. Closely-coupled ALE3D simulations of these experiments, utilizing the multi-phase convective burn model, provide detailed predictions of the reacted mass fraction and deflagration front acceleration. During the preinitiation heating phase of these experiments, the solid HMX portion of the PBX-9501 undergoes a {beta}-phase to {delta}-phase transition which damages the explosive and induces porosity. The multi-phase convective burn model results demonstrate that damaged particle size and pressure are critical for predicting reaction speed and violence. In the model, energetic parameters are taken from LLNL's thermochemical-kinetics code Cheetah and burn rate parameters from Son et al. (2000). Model predictions of an accelerating deflagration front are in qualitative agreement with the experimental images assuming a mode particle diameter in the range 300-400 {micro}m. There is uncertainty in the initial porosity caused by thermal damage of PBX-9501 and, thus, the effective surface area for burning. To better understand these structures, we employ x-ray computed tomography (XRCT) to examine the microstructure of PBX-9501 before and after thermal damage. Although lack of contrast between grains and binder prevents the determination of full grain size distribution in this material, there are many domains visible in thermally damaged PBX-9501 with diameters in the 300-400 {micro}m range.

  8. Molecular Dynamics Simulation of Thermal Sensitivity,Thermal Expansion and Mechanical Properties of PBX9501%PBX9501热感度、热膨胀及力学性能的分子动力学模拟

    Institute of Scientific and Technical Information of China (English)

    张文英; 邓晓雅; 陈思瑾; 吕臻珂; 洪慧玲; 袁帅; 唐红; 豆育升

    2016-01-01

    Molecular dynamics simulation was used to explore the thermal sensitivity ,thermal expansion and mechanical properties of PBX9501 explosive at different temperatures and pressures .The change in maximum trigger bond lengths of components in the sysem was used to judge the influence of temperature on the thermal sensitivity of the system .The ther‐mal expansion coefficients at different temperatures were predicted .The variations of mechanical properties with tempera‐tures and pressures were analyzed by static mechanics theory .The results show that the sensitivity of PBX9501 increases with increasing temperature in the range of 295-450 K and the maximum trigger bond length increases significantly at 375 K .The thermal expansion coefficient decreases with the increase of temperature .The brittleness is more remarkable with increasing temperature ,and the toughness is better with increasing pressure .%采用分子动力学模拟研究了不同温度和压强条件下PBX9501炸药的热感度、热膨胀和力学性能。通过体系中各组分最大引发键键长的变化判断温度对其热感度的影响;预测了 PBX9501体系在不同温度下的热膨胀系数;采用静态力学理论分析其力学性能随温度和压强的变化。结果表明,在295~450 K ,随温度的升高,PBX9501炸药的敏感性增大,且在375K时其引发键的最大键长显著增大;热膨胀系数随温度升高而减小;随温度升高其脆性越明显,随压强的增加其韧性越好。

  9. Development and applications of rectangular box-type explosively bonded structures for high-heat-load beamline components

    Science.gov (United States)

    Shu, D.; Chang, J.; Kuzay, T. M.; Brasher, D. G.

    2001-07-01

    Explosive bonding technology is a good choice to join dissimilar materials, such as 304L stainless steel and GlidCop AL-15, and is used extensively in making the advanced photon source (APS) high-heat-load beamline and front-end components. It is a bonding method in which the controlled energy of a detonating explosive is used to create a metallurgical bond between two or more similar or dissimilar materials. In recent years, special explosive bonding units with rectangular box-type joints were developed for the APS new high-heat-load beamline components. Based on this new technique, the box form of the component could be built in two halves first, then welded together. Therefore, beamline designers have more freedom to optimize the cooling surface geometry.

  10. Grit-mediated frictional ignition of a polymer-bonded explosive during oblique impacts: Probability calculations for safety engineering

    International Nuclear Information System (INIS)

    Frictional heating of high-melting-point grit particles during oblique impacts of consolidated explosives is considered to be the major source of ignition in accidents involving dropped explosives. It has been shown in other work that the lower temperature melting point of two frictionally interacting surfaces will cap the maximum temperature reached, which provides a simple way to mitigate the danger in facilities by implementing surfaces with melting points below the ignition temperature of the explosive. However, a recent series of skid testing experiments has shown that ignition can occur on low-melting-point surfaces with a high concentration of grit particles, most likely due to a grit–grit collision mechanism. For risk-based safety engineering purposes, the authors present a method to estimate the probability of grit contact and/or grit–grit collision during an oblique impact. These expressions are applied to potentially high-consequence oblique impact scenarios in order to give the probability of striking one or more grit particles (for high-melting-point surfaces), or the probability of one or more grit–grit collisions occurring (for low-melting-point surfaces). The probability is dependent on a variety of factors, many of which can be controlled for mitigation to achieve acceptable risk levels for safe explosives handling operations. - Highlights: • Unexpectedly, grit-mediated ignition of a PBX occurred on low-melting point surfaces. • On high-melting surfaces frictional heating is due to a grit–surface interaction. • For low-melting point surfaces the heating mechanism is grit–grit collisions. • A method for estimating the probability of ignition is presented for both surfaces

  11. Extensive Characterisation of Copper-clad Plates, Bonded by the Explosive Technique, for ITER Electrical Joints

    CERN Document Server

    Langeslag, S A E; Libeyre, P; Gung, C Y

    2015-01-01

    Cable-in-conduit conductors will be extensively implemented in the large superconducting magnet coils foreseen to confine the plasma in the ITER experiment. The design of the various magnet systems imposes the use of electrical joints to connect unit lengths of superconducting coils by inter-pancake coupling. These twin-box lap type joints, produced by compacting each cable end in into a copper - stainless steel bimetallic box, are required to be highly performing in terms of electrical and mechanical prop- erties. To ascertain the suitability of the first copper-clad plates, recently produced, the performance of several plates is studied. Validation of the bonded interface is carried out by determining microstructural, tensile and shear characteristics. These measure- ments confirm the suitability of explosion bonded copper-clad plates for an overall joint application. Additionally, an extensive study is conducted on the suitability of certain copper purity grades for the various joint types.

  12. MESOSCALE MODELING OF DEFLAGRATION-INDUCED DECONSOLIDATION IN POLYMER-BONDED EXPLOSIVES

    Energy Technology Data Exchange (ETDEWEB)

    Springer, H K; Glascoe, E A; Reaugh, J E; Kercher, J R; Maienschein, J L

    2011-08-01

    Initially undamaged polymer-bonded explosives can transition from conductive burning to more violent convective burning via rapid deconsolidation at higher pressures. The pressure-dependent infiltration of cracks and pores, i.e., damage, by product gases at the burn-front is a key step in the transition to convective burning. However, the relative influence of pre-existing damage and the evolution of deflagration-induced damage during the transition to convective burning is not well understood. The objective of this study is to investigate the role of microstructure and initial pressurization on deconsolidation. We performed simulations using the multi-physics hydrocode, ALE3D. HMX-Viton A served as our model explosive. A Prout-Tompkins chemical kinetic model, Vielle's Law pressure-dependent burning, Gruneisen equation-of-state, and simplified strength model were used for the HMX. The propensity for deconsolidation increased with increasing defect size and decreasing initial pressurization, as measured by the increase in burning surface area. These studies are important because they enable the development of continuum-scale damage models and the design of inherently safer explosives.

  13. Macroscopic crack formation and extension in pristine and artificially aged PBX 9501

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Cheng [Los Alamos National Laboratory; Thompson, Darla G [Los Alamos National Laboratory

    2010-01-01

    A technique has been developed to quantitatively describe macroscopic cracks, both their location and extent, in heterogeneous high explosive and mock materials. By combining such a technique with the deformation field measurement using digital image correlation (DIC), we conduct observation and measurement of the initiation, extension, and coalescence of internal cracks in the compression of Brazilian disk made of pristine and artificially aged PBX 9501 hjgh explosives. Our results conclude quantitatively that aged PBX 9501 is not only weaker but also much more brittle than the pristine one, thus is more susceptible to macroscopic cracking.

  14. Ignition probability of polymer-bonded explosives accounting for multiple sources of material stochasticity

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S.; Barua, A.; Zhou, M., E-mail: min.zhou@me.gatech.edu [The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0405 (United States); Horie, Y. [Air Force Research Lab, Munitions Directorate, 2306 Perimeter Road, Eglin AFB, Florida 32542 (United States)

    2014-05-07

    Accounting for the combined effect of multiple sources of stochasticity in material attributes, we develop an approach that computationally predicts the probability of ignition of polymer-bonded explosives (PBXs) under impact loading. The probabilistic nature of the specific ignition processes is assumed to arise from two sources of stochasticity. The first source involves random variations in material microstructural morphology; the second source involves random fluctuations in grain-binder interfacial bonding strength. The effect of the first source of stochasticity is analyzed with multiple sets of statistically similar microstructures and constant interfacial bonding strength. Subsequently, each of the microstructures in the multiple sets is assigned multiple instantiations of randomly varying grain-binder interfacial strengths to analyze the effect of the second source of stochasticity. Critical hotspot size-temperature states reaching the threshold for ignition are calculated through finite element simulations that explicitly account for microstructure and bulk and interfacial dissipation to quantify the time to criticality (t{sub c}) of individual samples, allowing the probability distribution of the time to criticality that results from each source of stochastic variation for a material to be analyzed. Two probability superposition models are considered to combine the effects of the multiple sources of stochasticity. The first is a parallel and series combination model, and the second is a nested probability function model. Results show that the nested Weibull distribution provides an accurate description of the combined ignition probability. The approach developed here represents a general framework for analyzing the stochasticity in the material behavior that arises out of multiple types of uncertainty associated with the structure, design, synthesis and processing of materials.

  15. Steady Deflagration of PBX-9501 Within a Copper Cylinder

    Energy Technology Data Exchange (ETDEWEB)

    Pemberton, Steven J. [Los Alamos National Laboratory; Herrera, Dennis H. [Los Alamos National Laboratory; Herrera, Tommy J. [Los Alamos National Laboratory; Arellano, Jesus C. [Los Alamos National Laboratory; Sandoval, Thomas D. [Los Alamos National Laboratory

    2012-06-26

    A copper cylinder cook-off experiment has been designed to cause steady deflagration in PBX-9501 explosive material. The design is documented and preliminary copper expansion results are presented for steady deflagration with a reaction speed of 1092 +/- 24 m/s. The expansion of reaction products from the detonation of an explosive is something that is well understood, and reasonably simulated using documented equations of state (EOS) for many explosives of interest. These EOS were historically measured using a 'standard' copper cylinder test design; this design comprised an annealed, oxygen-free high conductivity (OFHC) copper tube filled with explosive material and detonated from one end. Expansion of the copper wall was measured as a function of time using either a streak camera (for classic testing), or more recently using laser velocimetry techniques. Expansion data were then used to derive the EOS in various preferred forms - which are not discussed here for the sake of brevity. [Catanach, et. al., 1999] When an explosive deflagrates rather than detonating, simulation becomes more difficult. Reaction products are released on a slower time scale, and the reactions are much more affected by the geometry and local temperature within the reaction environment. It is assumed that the standard, documented EOS will no longer apply. In an effort to establish a first order approximation of deflagration product behavior, a cook-off test has been designed to cause steady deflagration in PBX-9501 explosive material, and to record the copper expansion profile as a function of time during this test. The purpose of the current paper is to document the initial test design and report some preliminary results. A proposal for modification of the design is also presented.

  16. THREE-DIMENSIONAL IGNITION AND GROWTH REACTIVE FLOW MODELING OF PRISM FAILURE TESTS ON PBX 9502

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, M L; Tarver, C M

    2006-06-20

    The Ignition and Growth reactive flow model for shock initiation and detonation of solid explosives based on triaminotirnitrobenzene (TATB) is applied to three-dimensional detonation wave propagation. The most comprehensive set of three-dimensional detonation wave propagation data is that measured using the trapezoidal prism test. In this test, a PBX 9501 (95% HMX, 2.5% Estane, and 2.5% BDNPA/F) line detonator initiates a detonation wave along the trapezoidal face of a PBX 9502 (95% TATB and 5% Kel-F binder) prism. The failure thickness, which has been shown experimentally to be roughly half of the failure diameter of a long cylindrical charge, is measured after 50 mm of detonation wave propagation by impact with an aluminum witness plate. The effects of confinement impedance on the PBX 9502 failure thickness have been measured using air (unconfined), water, PMMA, magnesium, aluminum, lead, and copper placed in contact with the rectangular faces of the prism parallel to the direction of detonation propagation. These prism test results are modeled using the two-dimensional PBX 9502 Ignition and Growth model parameters determined by calculating failure diameter and tested on recent corner turning experiments. Good agreement between experimentally measured and calculated prism failure thicknesses for unconfined and confined PBX 9502 is reported.

  17. ODTX Measurements and Simulations on Ultra Fine TATB and PBX-9502

    Energy Technology Data Exchange (ETDEWEB)

    Koerner, J; Maienschein, J; Burnham, A; Wemhoff, A

    2007-07-06

    We measure the time to explosion of 12.7 mm diameter spheres of ultra fine TATB and PBX-9502 (95 wt% TATB, 5 wt% Kel-F 800) at 85.0, 92.5, and 98.0 percent of theoretical maximum density (TMD) in confined and unconfined configurations and at several elevated temperatures with the Lawrence Livermore National Laboratory (LLNL) One Dimensional Time to Explosion (ODTX) apparatus. Time to explosion data provide insight into the relative ease of thermal ignition and allow for the calibration of kinetic parameters. The measurements show that PBX-9502 is more thermally stable than ultra fine TATB, that unconfined samples are slightly more thermally stable than confined ones, and that lower density samples are more thermally stable than higher density ones. 'Go/no go' data at the lowest temperatures yield an experimental measurement of the critical temperature, which is the temperature at which an explosive can be heated indefinitely without undergoing self-heating and concomitant rapid and violent decomposition. Critical temperatures ranges for 12.7 mm diameter spheres of 98% TMD ultra fine TATB and PBX-9502 are 213-230 C and 234-239 C, respectively. Experimental data are modeled with ALE3D and kinetic parameters are determined. These kinetic parameters, when coupled with thermal property data, provide good prediction of the time to explosion.

  18. Shock Initiation of Damaged Explosives

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-10-22

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

  19. Pressure Wave Measurements During Thermal Explosion of HMX-Based High Explosives

    Energy Technology Data Exchange (ETDEWEB)

    Forbes, J W; Garcia, F; Tarver, C M; Urtiew, P A; Greenwood, D W; Vandersall, K S

    2002-06-27

    Five different experiments on thermal heating of explosive materials have been performed. Three experiments thermally exploded PBX 9501 (HMX/Estane/BDNPA-F; 9512.512.5 wt %) donor charges while two others thermally exploded LX-04 (HMX/Viton A; 85/15 wt %). These donor charges were encased in 304 stainless steel. The transmitted two-dimensional pressure waves were measured by gauges in acceptor cylinders of Teflon, PBX 9501, or LX-04 that were in contact with the donors' steel case. A fifth experiment measured the pressure in an acceptor charge of PBX 9501 that had a 100 mm stand-off from the top of the steel case of the thermally cooked off PBX 9501 donor charge. Reactive flow hydrodynamic modeling using a rapid deflagration velocity of approximately 500 m/s was able to reproduce the pressure gauge records for both the in contact and stand off experiments that used PBX 9501 donors and acceptors.

  20. Coating and Characterization of Mock and Explosive Materials

    Directory of Open Access Journals (Sweden)

    Emily M. Hunt

    2012-01-01

    Full Text Available This project develops a method of manufacturing plastic-bonded explosives by using use precision control of agglomeration and coating of energetic powders. The energetic material coating process entails suspending either wet or dry energetic powders in a stream of inert gas and contacting the energetic powder with atomized droplets of a lacquer composed of binder and organic solvent. By using a high-velocity air stream to pneumatically convey the energetic powders and droplets of lacquer, the energetic powders are efficiently wetted while agglomerate drying begins almost immediately. The result is an energetic powder uniformly coated with binder, that is, a PBX, with a high bulk density suitable for pressing. Experiments have been conducted using mock explosive materials to examine coating effectiveness and density. Energetic materials are now being coated and will be tested both mechanically and thermally. This allows for a comprehensive comparison of the morphology and reactivity of the newly coated materials to previously manufactured materials.

  1. Simulation investigations in the binding energy and mechanical properties of HMX-based polymer-bonded explosives

    Institute of Scientific and Technical Information of China (English)

    XIAO Jijun; FANG Guoyong; JI Guangfu; XIAO Heming

    2005-01-01

    The molecular simulations of the well-known high explosive β-HMX (cyclotetramethylene tetranitramine) and its fluorine containing polymer-bonded explosives (PBXs) were carried out with the combination method of quantum mechanics, molecular mechanics and molecular dynamics. The atomic cluster model, containing the β-HMX molecule and the polymer molecule whose chain dimension was about the same as β-HMX's, was fully optimized by AM1 and PM3 semi-empirical molecular orbital and molecular mechanical methods using COMPASS and PCFF force field. Then the calculated binding energy is found to be linearly correlated to each other. Molecular dynamics simulations using COMPASS force field were performed for β-HMX crystal and the PBXs involving β-HMX and a series of fluorine containing polymers. Their elastic coefficients, moduli and Poisson's ratios were calculated. It is found that the mechanical properties of β-HMX can be effectively improved by blending with fluorine containing polymers in small amounts.

  2. Pre-ignition confinement and deflagration violence in LX-10 and PBX 9501

    Science.gov (United States)

    Tringe, J. W.; Glascoe, E. A.; McClelland, M. A.; Greenwood, D.; Chambers, R. D.; Springer, H. K.; Levie, H. W.

    2014-08-01

    In thermal explosions of the nitramine octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX)-based explosives LX-10 and PBX-9501, the pre-ignition spatial and temporal heating profile defines the ignition location. The ignition location then determines the extent of inertial confinement and the violence of the resulting deflagration. In this work, we present results of experiments in which ˜23 g cylinders of LX-10 and PBX 9501 in thin-walled aluminum confinement vessels were subjected to identical heating profiles but which presented starkly different energy release signatures. Post-explosion LX-10 containment vessels were completely fragmented, while the PBX 9501 vessels were merely ruptured. Flash x-ray radiography images show that the initiation location for the LX-10 is a few mm farther from the end caps of the vessel relative to the initiation location of PBX 9501. This difference increases deflagration confinement for LX-10 at the time of ignition and extends the pressurization time during which the deflagration front propagates in the explosive. The variation in the initiation location, in turn, is determined by the thermal boundary conditions, which differ for these two explosives because of the larger coefficient of thermal expansion and greater thermal stability of the Viton binder in LX-10 relative to the estane and bis(2,2-dinitropropyl) acetal/formal binder of the PBX 9501. The thermal profile and initiation location were modeled for LX-10 using the hydrodynamics and structures code ALE3D; results indicate temperatures in the vicinity of the ignition location in excess of 274 °C near the time of ignition. The conductive burn rates for these two explosives, as determined by flash x-ray radiography, are comparable in the range 0.1-0.2 mm/μs, somewhat faster than rates observed by strand burner experiments for explosives in the temperature range 150-180 °C and pressures up to 100 MPa. The thinnest-wall aluminum containment vessels presented here

  3. Pre-ignition confinement and deflagration violence in LX-10 and PBX 9501

    Energy Technology Data Exchange (ETDEWEB)

    Tringe, J. W., E-mail: tringe2@llnl.gov; Glascoe, E. A.; McClelland, M. A.; Greenwood, D.; Chambers, R. D.; Springer, H. K.; Levie, H. W. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2014-08-07

    In thermal explosions of the nitramine octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX)-based explosives LX-10 and PBX-9501, the pre-ignition spatial and temporal heating profile defines the ignition location. The ignition location then determines the extent of inertial confinement and the violence of the resulting deflagration. In this work, we present results of experiments in which ∼23 g cylinders of LX-10 and PBX 9501 in thin-walled aluminum confinement vessels were subjected to identical heating profiles but which presented starkly different energy release signatures. Post-explosion LX-10 containment vessels were completely fragmented, while the PBX 9501 vessels were merely ruptured. Flash x-ray radiography images show that the initiation location for the LX-10 is a few mm farther from the end caps of the vessel relative to the initiation location of PBX 9501. This difference increases deflagration confinement for LX-10 at the time of ignition and extends the pressurization time during which the deflagration front propagates in the explosive. The variation in the initiation location, in turn, is determined by the thermal boundary conditions, which differ for these two explosives because of the larger coefficient of thermal expansion and greater thermal stability of the Viton binder in LX-10 relative to the estane and bis(2,2-dinitropropyl) acetal/formal binder of the PBX 9501. The thermal profile and initiation location were modeled for LX-10 using the hydrodynamics and structures code ALE3D; results indicate temperatures in the vicinity of the ignition location in excess of 274 °C near the time of ignition. The conductive burn rates for these two explosives, as determined by flash x-ray radiography, are comparable in the range 0.1–0.2 mm/μs, somewhat faster than rates observed by strand burner experiments for explosives in the temperature range 150–180 °C and pressures up to 100 MPa. The thinnest-wall aluminum containment vessels

  4. Pre-ignition confinement and deflagration violence in LX-10 and PBX 9501

    International Nuclear Information System (INIS)

    In thermal explosions of the nitramine octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX)-based explosives LX-10 and PBX-9501, the pre-ignition spatial and temporal heating profile defines the ignition location. The ignition location then determines the extent of inertial confinement and the violence of the resulting deflagration. In this work, we present results of experiments in which ∼23 g cylinders of LX-10 and PBX 9501 in thin-walled aluminum confinement vessels were subjected to identical heating profiles but which presented starkly different energy release signatures. Post-explosion LX-10 containment vessels were completely fragmented, while the PBX 9501 vessels were merely ruptured. Flash x-ray radiography images show that the initiation location for the LX-10 is a few mm farther from the end caps of the vessel relative to the initiation location of PBX 9501. This difference increases deflagration confinement for LX-10 at the time of ignition and extends the pressurization time during which the deflagration front propagates in the explosive. The variation in the initiation location, in turn, is determined by the thermal boundary conditions, which differ for these two explosives because of the larger coefficient of thermal expansion and greater thermal stability of the Viton binder in LX-10 relative to the estane and bis(2,2-dinitropropyl) acetal/formal binder of the PBX 9501. The thermal profile and initiation location were modeled for LX-10 using the hydrodynamics and structures code ALE3D; results indicate temperatures in the vicinity of the ignition location in excess of 274 °C near the time of ignition. The conductive burn rates for these two explosives, as determined by flash x-ray radiography, are comparable in the range 0.1–0.2 mm/μs, somewhat faster than rates observed by strand burner experiments for explosives in the temperature range 150–180 °C and pressures up to 100 MPa. The thinnest-wall aluminum containment vessels

  5. PBX-M vacuum vessel seal upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Kozub, T.; Barnes, G.; Chrzanowski, J. [Princeton Plasma Physics Lab., NJ (United States)] [and others

    1995-12-31

    This paper addresses the project to restore and improve the sixteen year old elastomer seals on the PBX-M vacuum vessel. This work was performed to eliminate age degradation failures and to enhance future performance and reliability.

  6. Pressure Measurements in a PBX 9501 Gauged Acceptor When Impacted by a Steel Plate that is Accelerated by a Thermally Cooked Off PBX 9501 Charge

    Energy Technology Data Exchange (ETDEWEB)

    Forbes, J W; Garcia, F; Urtiew, P A; Vandersall, K S; Greenwood, D W; Tarver, C M

    2002-03-11

    Measuring the violence of a thermal explosion of a cased explosive is important for evaluating safety issues of explosive devices in fires. A sympathetic initiation scenario was studied here where a 9.0 cm diameter by 2.5 cm thick disc of PBX 9501 donor charge encased in a 304 stainless steel assembly was heated on top and bottom flat surfaces until it thermally exploded. The initial heating rate at the metal/explosive interface was 5 C per minute until it reaches 170 C; then this temperature is held for 35 minutes to allow temperature equilibration to within a few degrees throughout the explosive. The heating resumed at a rate of 1 C per minute until the PBX 9501 donor thermally exploded. A PBX 9501 acceptor charge with carbon resistor and manganin foil pressure gauges inserted at various depths was placed at a 10 cm standoff distance from the donor charge's top steel cover plate. Piezoelectric arrival time pins were placed in front of the acceptor surface to measure the velocity and shape of the impacting plate. The stainless steel cover plate of the donor charge had a nominal velocity of 0.55 {+-} 0.04 mm/{micro}s upon impact and was non-symmetrically warped. The impact of the tilted curved plate induced a three-dimensional compression wave into the acceptor. The rise times of the pressure waves were nominally 1.5 {micro}s with the closest carbon resistor gauges giving peak pressure of 10 kb that decayed to 3 kb for a wave run distance of 2.4 cm.

  7. Shock Initiation of New and Aged PBX 9501 Measured with Embedded Electromagnetic Particle Velocity Gauges

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-09-01

    We have used an embedded electromagnetic particle velocity gauge technique to measure the shock initiation behavior in PBX 9501 explosive. Up to twelve separate particle velocity wave profile measurements have been made at different depths in a single experiment. These detail the growth from an input shock to a detonation. In addition, another gauge element called a ''shock tracker'' has been used to monitor the progress of the shock front as a function of time and position as it moves through the explosive sample. This provides data similar to that obtained in a traditional explosively driven wedge test and is used to determine the position and time that the wave attains detonation. Run distance-to-detonation vs. input pressure (Pop-plot) data and particle velocity wave profile data have been obtained on new PBX 9501 pressed to densities of 1.826, 1.830, and 1.837 g/cm{sup 3}. In addition, the same measurements were performed on aged material recovered from dismantled W76 and W78 weapons. The input pressure range covered was 3.0 to 5.2 GPa. All results to date show shock sensitivity to be a function only of the initial density and not of age. PBX 9501 shock initiates the same after 17 years in stockpile as it does on the day it is pressed. Particle velocity wave profiles show mixed heterogeneous initiation (growth in the front) and homogeneous initiation (growth behind the front).

  8. DDT of hot, thermally damaged PBX 9501 in heavy confinement

    Energy Technology Data Exchange (ETDEWEB)

    Parker, Gary R [Los Alamos National Laboratory; Dickerson, Peter M [Los Alamos National Laboratory; Asay, Blaine W [Los Alamos National Laboratory; Mc Afee, John M [Los Alamos National Laboratory

    2010-01-01

    The research presented examines DDT of cylinders of PBX 9501 damaged above 180 C in heavy confinement for 0-3 hours and end-ignited or ramped until self-ignition (cookoff) occurred. Progression of luminous reaction was observed by streak photography through a glass-filled slit running the length of the cylinder. Post-mortem analysis of the steel DDT tubes was also done for correlation with the optical records. Results indicate that repeatable, Type I DDT was observed to occur in hot, thermally damaged PBX 9501 with low levels of porosity. It was demonstrated that multiple parameters affect DDT behavior, most likely in a coupled fashion. These parameters are porosity, ignition temperature and thermal soak duration. Conditions leading up to cookoff were shown to sensitize the HE to DDT by increasing likelihood and decreasing run length. Over the range of porosities (0-37%) and ignition temperatures (180-235 C), run lengths and detonation velocities varied, respectively, from approximately 22-109 mm and 6.0-8.3 mm {micro}s{sup -1}. This work fills a valuable and realistic space in the understanding of high explosive violent reaction, including DDT, in abnormal thermal environments.

  9. Analysis list: PBX2 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available PBX2 Digestive tract + hg19 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/PB...X2.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/PBX2.5.tsv http://dbarchive.biosciencedbc....jp/kyushu-u/hg19/target/PBX2.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/PBX2.Digestive_trac

  10. Exploring a Detonation Nature of Mesoscopic Perturbations and Ejecta Formation from the Mesoscale Probing of the PBX-driven Liners

    Science.gov (United States)

    Plaksin, Igor; Guiruis, Raafat; Rodrigues, Luis; Mendes, Ricardo; Plaksin, Svyatoslav; Fernandes, Eduardo; Ferreira, Claudia

    2015-06-01

    Ejecting debris from free surface of liner is of considerable interest at optimization of explosive devices, in which the PBX-driven liner effects shock compression of gaseous matter. Following factors were historically considered as main drivers of material ejection: granular microstructure of liner material, roughness and surface defects of liner, and shock pressure time history in PBX-driven liner. In contrast to existing models, we are considering the small scale fluctuations of detonation flow as probable dominating factor of surface jetting in the PBX-driven collapsing liners. Obtained experimental evidence is indicative that jetting from the liners is caused by meso-scale perturbations of PBX detonations, which are identified as (1) ejecta of overdriven detonation products through detonation front, (2) ejecta-driven detonation cells, and (3) galloping detonation front motion. Spatially resolved scenarios of each of phenomena (1-3) were obtained in experiments with copper-liners and HMX-based PBXs fabricated on maximum packing density of crystalline constituents. Both the DRZ-induced perturbations translated to a PBX-driven liner and the ejected debris were recorded and quantitatively measured in the mesoscale range with application of the 96-channel optical analyzer MCOA-UC. Work was supported by the ONR and ONR Global Grants N00014-12-1-0477 and N62909-12-1-7131 with Drs. Clifford Bedford and John Zimmerman Program Managers.

  11. Behavior and mechanism of the bonding interface of 0Cr18Ni9/16MnR by explosive welding

    Institute of Scientific and Technical Information of China (English)

    Shi Changgen; Tan Yefa; Hong Jin; Liu Peng

    2010-01-01

    In order to investigate the bonding behavior and mechanism of the interface prepared by explosive welding,the bonding interfaces of OCr18Ni9/16MnR were observed and analyzed by means of optical microscope(OM),scanning electron microscope(SEM)and electron probe microanalysis(EPMA).It is found that the welding interfaces are wavy due to the wavy explosive loading.There are three kinds of bonding interfaces i.e.big wave,small wave and micro wave.There are a few seam defects and all elements contents are less than both of the base and flyer plate in the transition zone of big wavy interface.Moreover,some"holes"result in the lowest bonding strength of big wavy interface nearby the interface in the base plate.All elements contents of the small wavy interface are between two metals,and there are few seam and hole defects,so it is the higher for the bonding strength of small wavy interface.There is no transition zone and defects in the micro wavy interface,so the interface is the best.To gain the high quality small and micro wavy bonding interface the explosive charge should be controlled.

  12. Progress in measuring detonation wave profiles in PBX9501

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-12-31

    The authors have measured detonation wave profiles in PBX9501 (95 wt% HMX and 5 wt% binders) using VISAR. Planar detonations were produced by impacting the explosive with projectiles launched in a 72 mm bore gas gun. Particle velocity wave profiles were measured at the explosive/window interface using two VISARs with different fringe constants. Windows with very thin vapor deposited aluminum mirrors were used for all experiments. PMMA windows provided an undermatch, and LiF (Lithium Fluoride) windows provided an overmatch to the explosive, reacted and unreacted. While the present experiments do not have adequate time resolution to adequately resolve the ZND spike condition, they do constrain it to lie between 38.7 and 53.4 Gpa or 2.4 and 3.3 km/s. Accurate knowledge of the CJ state places the reaction zone length at 35 {+-} 12 ns ({approx} 0.3 mm). The present experiments do not show any effect of the window on the reaction zone; both window materials result in the same reaction zone length.

  13. Experimental Study of the Impact Damage of Composition B and Plastic Bonded Explosive

    Institute of Scientific and Technical Information of China (English)

    陈鹏万; 黄风雷; 丁雁生

    2003-01-01

    A long-pulse low-velocity gas gun with a gas buffer is used to induce impact damage in cast Composition B and hot pressed PBXN-5. To obtain different damage states, a range of projectile velocities are used by controlling the launching pressure of gas gun. The stress history during impact loading is recorded. Various methods are used to characterize the damage state of impacted explosive samples. The microstructure is examined by use of scanning electronic microscopy (SEM) and polarized light microscopy (PLM). The densities and ultrasonic attenuation are also measured. The results show that both Composition B and PBXN-5 exhibit some damage characteristics of brittle materials. However, due to the difference in compositions, PBXN-5 exhibits better resistance to impact loading than Composition B.

  14. Analysis list: Pbx1 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pbx1 Embryo,Embryonic fibroblast,Muscle + mm9 http://dbarchive.biosciencedbc.jp/kyu...shu-u/mm9/target/Pbx1.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Pbx1.5.tsv http://dbarchiv...e.biosciencedbc.jp/kyushu-u/mm9/target/Pbx1.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Pbx1.Embryo.tsv,http://dba...rchive.biosciencedbc.jp/kyushu-u/mm9/colo/Pbx1.Embryonic_fibroblast.tsv,http://dba...rchive.biosciencedbc.jp/kyushu-u/mm9/colo/Pbx1.Muscle.tsv http://dbarchive.bioscienced

  15. Analysis list: PBX1 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available PBX1 Blood,Breast,Digestive tract + hg19 http://dbarchive.biosciencedbc.jp/kyushu-u.../hg19/target/PBX1.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/PBX1.5.tsv http://dbarchive.bioscience...dbc.jp/kyushu-u/hg19/target/PBX1.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/PBX1.B...lood.tsv,http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/PBX1.Breast.tsv,http://dbarchive.bioscience...dbc.jp/kyushu-u/hg19/colo/PBX1.Digestive_tract.tsv http://dbarchive.biosciencedbc.jp

  16. Pbx homeodomain proteins pattern both the zebrafish retina and tectum

    Directory of Open Access Journals (Sweden)

    Stout Jennifer

    2007-07-01

    Full Text Available Abstract Background Pbx genes encode TALE class homeodomain transcription factors that pattern the developing neural tube, pancreas, and blood. Within the hindbrain, Pbx cooperates with Hox proteins to regulate rhombomere segment identity. Pbx cooperates with Eng to regulate midbrain-hindbrain boundary maintenance, and with MyoD to control fast muscle cell differentiation. Although previous results have demonstrated that Pbx is required for proper eye size, functions in regulating retinal cell identity and patterning have not yet been examined. Results Analysis of retinal ganglion cell axon pathfinding and outgrowth in pbx2/4 null embryos demonstrated a key role for pbx genes in regulating neural cell behavior. To identify Pbx-dependent genes involved in regulating retino-tectal pathfinding, we conducted a microarray screen for Pbx-dependent transcripts in zebrafish, and detected genes that are specifically expressed in the eye and tectum. A subset of Pbx-dependent retinal transcripts delineate specific domains in the dorso-temporal lobe of the developing retina. Furthermore, we determined that some Pbx-dependent transcripts also require Meis1 and Gdf6a function. Since gdf6a expression is also dependent on Pbx, we propose a model in which Pbx proteins regulate expression of the growth factor gdf6a, which in turn regulates patterning of the dorso-temporal lobe of the retina. This, in concert with aberrant tectal patterning in pbx2/4 null embryos, may lead to the observed defects in RGC outgrowth. Conclusion These data define a novel role for Pbx in patterning the vertebrate retina and tectum in a manner required for proper retinal ganglion cell axon outgrowth.

  17. CL-20/TATB粘结炸药制备及其表征%Preparation and Characterization of CL-20/TATB Polymer Bonded Explosive

    Institute of Scientific and Technical Information of China (English)

    侯聪花; 于卫龙; 贾新磊; 王晶禹

    2016-01-01

    The insensitive high explosive 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) was selected for coating and desensitization of hexanitrohexaazaisowurtzitane (CL-20), another high explosive, after surface modification. About 1wt% Estane as a binder and 5wt% TATB as a deterrent were adopted in the preparation process, to obtain CL-20 based PBX by water slurry method, and SEM, XRD, DSC and impact sensitivity test were conducted. The results showed that TATB can be coated on the surface of CL-20 effectively, and the form of CL-20 didn´t change during the whole preparing process. Compared with CL-20/Estane without TATB, the thermal explosion critical temperature is increased 0.08℃,and the activation energy is increased 7.09 kJ·mol-1, the impact sensitivity of coated sample is reduced significantly, the characteristic drop height (H50) is increased from 30.64cm to 44.57cm, increased 45.5%.%使用钝感炸药三氨基三硝基苯(TATB)对高能炸药六硝基六氮杂异伍兹烷(CL-20)进行包覆和降感处理,制备过程中以1%的Estane作为粘结剂,5%的TATB作为钝感剂,采用水悬浮法制备了CL-20基PBX,并对其进行SEM、XRD、DSC以及撞击感度性能测试。结果表明:TATB可以有效地包覆在CL-20表面,在包覆过程中CL-20晶型未发生改变;与未添加TATB的CL-20/Estane粘结炸药相比,热爆炸临界温度提升了0.08℃,活化能提高了7.09kJ·mol-1,并且其撞击感度明显降低,特征落高(H50)由30.64cm提升至44.57cm,提升了45.5%。

  18. Pbx1 is required for adult subventricular zone neurogenesis.

    Science.gov (United States)

    Grebbin, Britta Moyo; Hau, Ann-Christin; Groß, Anja; Anders-Maurer, Marie; Schramm, Jasmine; Koss, Matthew; Wille, Christoph; Mittelbronn, Michel; Selleri, Licia; Schulte, Dorothea

    2016-07-01

    TALE-homeodomain proteins function as components of heteromeric complexes that contain one member each of the PBC and MEIS/PREP subclasses. We recently showed that MEIS2 cooperates with the neurogenic transcription factor PAX6 in the control of adult subventricular zone (SVZ) neurogenesis in rodents. Expression of the PBC protein PBX1 in the SVZ has been reported, but its functional role(s) has not been investigated. Using a genetic loss-of-function mouse model, we now show that Pbx1 is an early regulator of SVZ neurogenesis. Targeted deletion of Pbx1 by retroviral transduction of Cre recombinase into Pbx2-deficient SVZ stem and progenitor cells carrying floxed alleles of Pbx1 significantly reduced the production of neurons and increased the generation of oligodendrocytes. Loss of Pbx1 expression in neuronally committed neuroblasts in the rostral migratory stream in a Pbx2 null background, by contrast, severely compromised cell survival. By chromatin immunoprecipitation from endogenous tissues or isolated cells, we further detected PBX1 binding to known regulatory regions of the neuron-specific genes Dcx and Th days or even weeks before the respective genes are expressed during the normal program of SVZ neurogenesis, suggesting that PBX1 might act as a priming factor to mark these genes for subsequent activation. Collectively, our results establish that PBX1 regulates adult neural cell fate determination in a manner beyond that of its heterodimerization partner MEIS2. PMID:27226325

  19. Structural stability, vibrational, and bonding properties of potassium 1, 1'-dinitroamino-5, 5'-bistetrazolate: An emerging green primary explosive.

    Science.gov (United States)

    Yedukondalu, N; Vaitheeswaran, G

    2015-08-14

    Potassium 1,1'-dinitroamino-5,5'-bistetrazolate (K2DNABT) is a nitrogen rich (50.3% by weight, K2C2N12O4) green primary explosive with high performance characteristics, namely, velocity of detonation (D = 8.33 km/s), detonation pressure (P = 31.7 GPa), and fast initiating power to replace existing toxic primaries. In the present work, we report density functional theory (DFT) calculations on structural, equation of state, vibrational spectra, electronic structure, and absorption spectra of K2DNABT. We have discussed the influence of weak dispersive interactions on structural and vibrational properties through the DFT-D2 method. We find anisotropic compressibility behavior (bcompression. In addition, we have also calculated the electronic structure and absorption spectra using recently developed Tran Blaha-modified Becke Johnson potential. It is found that K2DNABT is a direct band gap insulator with a band gap of 3.87 eV and the top of the valence band is mainly dominated by 2p-states of oxygen and nitrogen atoms. K2DNABT exhibits mixed ionic (between potassium and tetrazolate ions) and covalent character within tetrazolate molecule. The presence of ionic bonding suggests that the investigated compound is relatively stable and insensitive than covalent primaries. From the calculated absorption spectra, the material is found to decompose under ultra-violet light irradiation. PMID:26277146

  20. PBX3 is a putative biomarker of aggressive prostate cancer.

    Science.gov (United States)

    Ramberg, Håkon; Grytli, Helene Hartvedt; Nygård, Ståle; Wang, Wanzhong; Ögren, Olov; Zhao, Sen; Løvf, Marthe; Katz, Betina; Skotheim, Rolf I; Bjartell, Anders; Eri, Lars Magne; Berge, Viktor; Svindland, Aud; Taskén, Kristin Austlid

    2016-10-15

    There is a great need to identify new and better prognostic and predictive biomarkers to stratify prostate cancer patients for optimal treatment. The aims of this study were to characterize the expression profile of pre-B cell leukemia homeobox (PBX) transcription factors in prostate cancer with an emphasis on investigating whether PBX3 harbours any prognostic value. The expression profile of PBX3 and PBX1 in prostate tissue was determined by immunohistochemical and immunoblot analysis. Furthermore, the expression of PBX3 transcript variants was analyzed by RT-PCR, NanoString Technologies®, and by analyzing RNA sequence data. The potential of PBX3 to predict prognosis, either at mRNA or protein level, was studied in four independent cohorts. PBX3 was mainly expressed in the nucleus of normal prostate basal cells, while it showed cytosolic expression in prostatic intraepithelial neoplasia and cancer cells. We detected four PBX3 transcript variants in prostate tissue. Competing risk regression analysis revealed that high PBX3 expression was associated with slower progression to castration resistant prostate cancer (sub-hazard ratio (SHR) 0.18, 95% CI: 0.081-0.42, p values aggressive prostate cancer. PMID:27273830

  1. (U) Analysis of shock-initiated PBX-9501 through porous CeO2

    Energy Technology Data Exchange (ETDEWEB)

    Fredenburg, David A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dattelbaum, Dana Mcgraw [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dennis-Koller, Darcie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-07-24

    The attenuation properties of an impact initiated PBX-9501 explosive through several thicknesses of CeO2 powder is investigated. The CeO2 is at an initial porous density of 4.0 g/cm3 , roughly 55 % of theoretical maximum density. Measurements of the input (into the powder) and propagated (through the powder) wave profiles are measured using optical velocimetry. Results show a reduction of the average wave speed, CX, and peak steady-state material velocity, uP , with increasing powder thickness from 1.5 - 5.0 mm.

  2. Behavior of the longitudinal acoustic velocity in PBX-9404 during thermal decomposition

    Energy Technology Data Exchange (ETDEWEB)

    Sutherland, H.J.; Kennedy, J.E.; Nunziato, J.W.

    1977-07-01

    Acoustic wave experiments were conducted on the heterogeneous explosive, PBX-9404, at a temperature of 116/sup 0/C and a frequency of 1 MHz to study the influence of thermal decomposition on the mechanical response of the material. The longitudinal phase velocity was approximately 2.2 km/s and was found to be essentially independent of the extent of decomposition until the stabilizer was depleted. Thereafter, the velocity increased slowly with time as the temperature was maintained. Several possible explanations for this observation are discussed in light of some information obtained in post-test chemical analysis.

  3. PBX Security and Forensics A Practical Approach

    CERN Document Server

    Androulidakis, Iosif I

    2013-01-01

    PBX Security and Forensics begins with an introduction to PBXs (Private Branch Exchanges) and the scene, statistics and involved actors. This book discusses confidentiality, integrity and availability threats in PBXs. The author examines the threats and the technical background as well as security and Forensics involving PBXs. The purpose of this book is to raise user awareness in regards to security and privacy threats present in PBXs, helping both users and administrators safeguard their systems.

  4. Mechanical Properties from PBX 9501 Pressing Study

    Science.gov (United States)

    Graff Thompson, Darla; Wright, Walter J.

    2004-07-01

    A PBX 9501 pressing study was conducted by researchers in ESA-WMM, LANL, to identify the hydrostatic pressing parameters most important in fabricating high-density parts with uniform density. In this study, 31 charges were pressed using a full permutation of six pressing parameters. Five charges from the set of 31 were selected for an evaluation of their mechanical properties, specifically uniaxial compression and tension. Charges were selected to 1) span the density range of the study, and 2) allow two direct comparisons of pressing parameters independent of bulk density (density has a well-established affect on some material properties). Three PBX 9501 charges pressed isostatically at Pantex Plant in Amarillo, TX were also included in the study. The tensile properties of the 8 charges varied significantly. Careful evaluation of the results suggests that an increase in pressing temperature may correlate with an increase in tensile stress (strength) and a decrease in strain (ductility). Trends in compression exist but are less pronounced. In an effort to explore the relationship between pressing temperature and tensile strength, four sheets of Estane polymer (a component of the PBX 9501 binder) were compression molded at 70, 90, 110 and 130°C. The tensile strength of Estane was observed to increase by a factor of nearly 20 when the molding temperature was increased from 70 to 90°C (strength increase was negligible beyond 90°C). We present an outline of ongoing work that will irrefutably quantify the mechanical property affects of both pressing temperature and dwell time on PBX 9501.(LA-UR 03-4842).

  5. Study of nano-nitramine explosives: preparation, sensitivity and application

    Directory of Open Access Journals (Sweden)

    Jie Liu

    2014-06-01

    Full Text Available Nano-nitramine explosives (RDX, HMX, CL-20 are produced on a bi-directional grinding mill. The scanning electron microscope (SEM observations show that the prepared particles are semi-spherical, and the narrow size distributions are characterized using the laser particle size analyzer. Compared with the micron-sized samples, the nano-products show obvious decrease in friction and impact sensitivities. In the case of shock sensitivities, nano-products have lower values by 59.9% (RDX, 56.4% (HMX, and 58.1% (CL-20, respectively. When nano-RDX and nano-HMX are used in plastic bonded explosives (PBX as alternative materials of micron-sized particles, their shock sensitivities are significantly decreased by 24.5% (RDX and 22.9% (HMX, and their detonation velocities are increased by about 1.7%. Therefore, it is expected to promote the application of nano-nitramine explosives in PBXs and composite modified double-based propellants (CMDBs so that some of their properties would be improved.

  6. Thermal Explosion Violence of HMX-Based and RDX-Based Explosives - Effects of Composition, Confinement, and Solid Phase Using the Scaled Thermal Explosion Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Maienschein, J L; Wardell, J F

    2002-08-26

    The Scaled Thermal Explosion Experiment (STEX) has been developed to quantify the violence of thermal explosion under well defined and carefully controlled initial and boundary conditions. Here we present results with HMX-based explosives (LX-04 and PBX-9501) and with Composition B. Samples are 2 inches (50 mm) in diameter and 8 inches (200 mm) in length, under confinement of 7,500-30,000 psi (50-200 MPa), with heating rates of 1-3 C/hr. We quantify reaction violence by measuring the wall velocity in the ensuing thermal explosion, and relate the measured velocity to that expected from a detonation. Results with HMX-based explosives (LX-04 and PBX-9501) have shown the importance of confinement and HMX solid phase, with reaction violence ranging from mild pressure bursts to near detonations. By contrast, Composition B has shown very violent reactions over a wide range of conditions.

  7. Thermal Explosion Violence of HMX-Based and RDX-Based Explosives - Effects of Composition, Confinement, and Solid Phase Using the Scaled Thermal Explosion Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Maienschein, J L; Wardell, J F

    2002-03-14

    The Scaled Thermal Explosion Experiment (STEX) has been developed to quantify the violence of thermal explosion under well defined and carefully controlled initial and boundary conditions. Here we present results with HMX-based explosives (LX-04 and PBX-9501) and with Composition B. Samples are 2 inches (50 mm) in diameter and 8 inches (200 mm) in length, under confinement of 7,500-30,000 psi (50-200 MPa), with heating rates of 1-3 C/hr. We quantify reaction violence by measuring the wall velocity in the ensuing thermal explosion, and relate the measured velocity to that expected from a detonation. Results with HMX-based explosives (LX-04 and PBX-9501) have shown the importance of confinement and HMX solid phase, with reaction violence ranging from mild pressure bursts to near detonations. By contrast, Composition B has shown very violent reactions over a wide range of conditions.

  8. MEIS and PBX homeobox proteins in ovarian cancer

    NARCIS (Netherlands)

    Crijns, A. P. G.; de Graeff, P.; Geerts, D.; ten Hoor, K. A.; Hollema, H.; van der Sluis, T.; Hofstra, R. M. W.; de Bock, G. H.; de Jong, S.; van der Zee, A. G. J.; de Vries, E. G. E.

    2007-01-01

    Three amino-acid loop extension (TALE) homeobox proteins MEIS and PBX are cofactors for HOX-class homeobox proteins, which control growth and differentiation during embryogenesis and homeostasis. We showed that MEIS and PBX expression are related to cisplatin resistance in ovarian cancer cell lines.

  9. pbx is required for pole and eye regeneration in planarians.

    Science.gov (United States)

    Chen, Chun-Chieh G; Wang, Irving E; Reddien, Peter W

    2013-02-01

    Planarian regeneration involves regionalized gene expression that specifies the body plan. After amputation, planarians are capable of regenerating new anterior and posterior poles, as well as tissues polarized along the anterior-posterior, dorsal-ventral and medial-lateral axes. Wnt and several Hox genes are expressed at the posterior pole, whereas Wnt inhibitory genes, Fgf inhibitory genes, and prep, which encodes a TALE-family homeodomain protein, are expressed at the anterior pole. We found that Smed-pbx (pbx for short), which encodes a second planarian TALE-family homeodomain transcription factor, is required for restored expression of these genes at anterior and posterior poles during regeneration. Moreover, pbx(RNAi) animals gradually lose pole gene expression during homeostasis. By contrast, pbx was not required for initial anterior-posterior polarized responses to wounds, indicating that pbx is required after wound responses for development and maintenance of poles during regeneration and homeostatic tissue turnover. Independently of the requirement for pbx in pole regeneration, pbx is required for eye precursor formation and, consequently, eye regeneration and eye replacement in homeostasis. Together, these data indicate that pbx promotes pole formation of body axes and formation of regenerative progenitors for eyes. PMID:23318641

  10. Analysis list: PBX3 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available PBX3 Blood,Digestive tract,Liver,Neural + hg19 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/PB...X3.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/PBX3.5.tsv http://dbarc...hive.biosciencedbc.jp/kyushu-u/hg19/target/PBX3.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/PB...X3.Blood.tsv,http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/PBX3.Digestiv...e_tract.tsv,http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/PBX3.Liver.tsv,http://dbarchive.bioscienced

  11. Continuous wave laser irradiation of explosives

    Energy Technology Data Exchange (ETDEWEB)

    McGrane, Shawn D.; Moore, David S.

    2010-12-01

    Quantitative measurements of the levels of continuous wave (CW) laser light that can be safely applied to bare explosives during contact operations were obtained at 532 nm, 785 nm, and 1550 nm wavelengths. A thermal camera was used to record the temperature of explosive pressed pellets and single crystals while they were irradiated using a measured laser power and laser spot size. A visible light image of the sample surface was obtained before and after the laser irradiation. Laser irradiation thresholds were obtained for the onset of any visible change to the explosive sample and for the onset of any visible chemical reaction. Deflagration to detonation transitions were not observed using any of these CW laser wavelengths on single crystals or pressed pellets in the unconfined geometry tested. Except for the photochemistry of DAAF, TATB and PBX 9502, all reactions appeared to be thermal using a 532 nm wavelength laser. For a 1550 nm wavelength laser, no photochemistry was evident, but the laser power thresholds for thermal damage in some of the materials were significantly lower than for the 532 nm laser wavelength. No reactions were observed in any of the studied explosives using the available 300 mW laser at 785 nm wavelength. Tables of laser irradiance damage and reaction thresholds are presented for pressed pellets of PBX9501, PBX9502, Composition B, HMX, TATB, RDX, DAAF, PETN, and TNT and single crystals of RDX, HMX, and PETN for each of the laser wavelengths.

  12. Penetration Evaluation of Explosively Formed Projectiles Through Air and Water Using Insensitive Munition: Simulative and Experimental Studies

    Directory of Open Access Journals (Sweden)

    M. Ahmed

    2016-02-01

    Full Text Available The process of formation, flying, penetration of explosively-formed projectiles (EFP and the effect of water on performance of the charge for underwater applications is simulated by Ansysis Autodyn 2D-Hydro code. The main objective of an explosively formed projectile designed for underwater applications is to disintegrate the target at longer standoff distances. In this paper we have simulated the explosively formed projectile from OFHC-Copper liner for 1200 conical angle. The Affect of water on the penetration of EFP is determined by simulations from Ansysis Autodyn 2-D Hydrocode and by varying depth of water from 1CD-5CD. The depth of penetration against steel target is measured experimentally. Flash X-Ray Radiography (FXR is used to capture EFP jet formation and its penetration against target is measured by depth of penetration experiments. Simulation results are compared with experimental results. The difference in simulated and experimental results for depth of penetration is about 7 mm, which lies within favorable range of error. The jet formation captured from FXR is quite clear and jet velocity determined from Flash X-ray radiography is the same as the ones obtained by using other high explosives. Therefore, it is indicated that Insensitive Munition (8701 can be utilized instead of Polymer Bonded Explosives (PBX for air and underwater environments with great reliability and without any hazard.

  13. Relative flow rates of explosive powders

    Energy Technology Data Exchange (ETDEWEB)

    Willson, V.P.

    1988-05-31

    A study was performed to determine the relative flow rates of various explosive powders and evaluate their adaptability for use in automated dispensing systems. Results showed that PBX 9407, LX-15, RX-26-BH, and HNAB are potential candidates for use in these systems. It was also shown that powders with graphite and stearate additives generated the least amount of static and were the easiest to handle.

  14. Gas Generation of Heated PBX 9502

    Energy Technology Data Exchange (ETDEWEB)

    Holmes, Matthew David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Parker, Gary Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-10-07

    Uniaxially pressed samples of PBX 9502 were heated until self-ignition (cookoff) in order to collect pressure and temperature data relevant for model development. Samples were sealed inside a small gas-tight vessel, but were mechanically unconfined. Long-duration static pressure rise, as well as dynamic pressure rise during the cookoff event, were recorded. Time-lapse photography of the sample was used to measure the thermal expansion of the sample as a function of time and temperature. High-speed videography qualitatively characterized the mechanical behavior and failure mechanisms at the time of cookoff. These results provide valuable input to modeling efforts, in order to improve the ability to predict pressure output during cookoff as well as the effect of pressure on time-toignition.

  15. Detonation shock dynamics calibration for pBX 9502 with temperature, density, and material lot variations

    Energy Technology Data Exchange (ETDEWEB)

    Hill, Larry G [Los Alamos National Laboratory; Aslam, Tariq D [Los Alamos National Laboratory

    2010-01-01

    We present a methodology for scaling the detonation shock dynamics D{sub n}[{kappa}] calibration function to accommodate variations in the HE starting material. We apply our model to the insensitive TATB-based explosive PBX 9502, for which we have enough front curvature rate stick data to characterize three material attributes: initial temperature T{sub 0}, nominal density {rho}{sub 0}, and manufacturing lot (representing different microstructures). A useful feature of the model is that it returns an absolute estimate for the reaction zone thickness, {delta}. Lacking demonstrated material metrics(s), we express microstructural variation indirectly, in terms of its effect on {delta}. This results in a D{sub n}[{kappa}] function that depends on T{sub 0}, {rho}{sub 0}, and {delta}. After examining the separate effects of each parameter on D{sub n}[{kappa}], we compute an arc geometry as a validation problem. We compare the calculation to a PBX 9502 arc experiment that was pressed from one of the calibrated HE lots. The agreement between the model and experiment is excellent. We compute worst, nominal, and best-performing material parameter combinations to show how much difference accrues throughout the arc.

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

    Energy Technology Data Exchange (ETDEWEB)

    Reaugh, J E

    2011-11-22

    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

  17. Application of Liquid Paraffin in Castable CL-20-Based PBX

    Science.gov (United States)

    Zhang, Pu; Guo, Xue-Yong; Zhang, Jing-Yuan; Jiao, Qing-Jie

    2014-10-01

    Hydroxy-terminated polybutadiene (HTPB)/CL-20 castable explosives plasticized with liquid paraffin were processed successfully by a cast-curing method. The compatibility of liquid paraffin with CL-20, influence of liquid paraffin on CL-20 phase transition, and viscosity of the cast mixture were tested and analyzed. The thermal decomposition characteristics, thermal stability, mechanical sensitivity, and velocity of detonation (VOD) of the HTPB/CL-20 plastic-bonded explosives (PBXs) were also measured. The experimental results showed that liquid paraffin was well compatible with CL-20, and it did not have a distinct effect on the ɛ- to γ-phase transition of CL-20. In addition, the casting mixture was free-flowing with sufficiently low viscosity. When the content of CL-20 is 90% by weight, the measured VOD reached 8,775 m/s (density of 1.78 g/cm3), and the PBXs exhibited moderate mechanical sensitivity and good thermal stability.

  18. Isolator fragmentation and explosive initiation tests

    Energy Technology Data Exchange (ETDEWEB)

    Dickson, Peter [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Rae, Philip John [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Foley, Timothy J. [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Novak, Alan M. [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Armstrong, Christopher Lee [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Baca, Eva V. [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Gunderson, Jake Alfred [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)

    2015-09-30

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

  19. Isolator fragmentation and explosive initiation tests

    Energy Technology Data Exchange (ETDEWEB)

    Dickson, Peter [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rae, Philip John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Foley, Timothy J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Novak, Alan M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Armstrong, Christopher Lee [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Baca, Eva V. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gunderson, Jake Alfred [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-19

    Three tests were conducted to evaluate the effects of firing an isolator in proximity to a barrier or explosive charge. The tests with explosive were conducted without a barrier, on the basis that since any barrier will reduce the shock transmitted to the explosive, bare explosive represents the worst-case from an inadvertent initiation perspective. No reaction was observed. The shock caused by the impact of a representative plastic material on both bare and cased PBX 9501 is calculated in the worst-case, 1-D limit, and the known shock response of the HE is used to estimate minimum run-to-detonation lengths. The estimates demonstrate that even 1-D impacts would not be of concern and that, accordingly, the divergent shocks due to isolator fragment impact are of no concern as initiating stimuli.

  20. Relationship between Pressure and Reaction Violence in Thermal Explosions

    Science.gov (United States)

    Smilowitz, Laura; Henson, Bryan; Rodriguez, George; Remelius, Dennis; Baca, Eva; Oschwald, David; Suvorova, Natalya

    2015-06-01

    Reaction violence of a thermal explosion is determined by the energy release rate of the explosive and the coupling of that energy to the case and surroundings. For the HMX and TATB based secondary high explosives studied, we have observed that temperature controls the time to explosion and pressure controls the final energy release rate subsequent to ignition. Pressure measurements in the thermal explosion regime have been notoriously difficult to make due to the extreme rise in temperature which is also occurring during a thermal explosion. We have utilized several different pressure measurement techniques for several different secondary high explosives. These techniques include commercially available piezoelectric and piezoresistive sensors which we have utilized in the low pressure (sub 30 MPa) range of PBX9502 thermal explosions, and fiber bragg grating sensors for the higher pressure range (up to GPa) for PBX9501 experiments. In this talk, we will compare the measurement techniques and discuss the pressures measured for the different formulations studied. Simultaneous x-ray radiography measurements of burn velocity will also be shown and correlations between pressure, burn velocity, and reaction violence will be discussed.

  1. Atomic-Scale Theoretical Studies of Fundamental Properties and Processes in CHNO Plastic-Bonded Explosive Constituent Materials under Static and Dynamic Compression

    Science.gov (United States)

    Sewell, Thomas

    2013-06-01

    The results of recent theoretical atomic-scale studies of CHNO plastic-bonded explosive constituent materials will be presented, emphasizing the effects of static and dynamic compression on structure, vibrational spectroscopy, energy redistribution, and dynamic deformation processes. Among the chemical compounds to be discussed are pentaerythritol tetranitrate (PETN), hexahydro-1,3,5-trinitro-1,3,5-s-triazine (RDX), nitromethane, and hydroxyl-terminated polybutadiene (HTPB). Specific topics to be discussed include pressure-dependent terahertz IR absorption spectra in crystalline PETN and RDX, microscopic material flow characteristics and energy localization during and after pore collapse in shocked (100)-oriented RDX, establishment of local thermodynamic temperature and the approach to thermal equilibrium in shocked (100)-oriented nitromethane, and structural changes and relaxation phenomena that occur in shocked amorphous cis-HTPB. In the case of shocked HTPB, comparisons will be made between results obtained using fully-atomic and coarse-grained (united atom) molecular dynamics force field models. Rather than attempting to discuss any given topic in extended detail, 3-4 vignettes will be presented that highlight outstanding scientific questions and the predictive methods and tools we are developing to answer them. The U.S. Defense Threat Reduction Agency and Office of Naval Research supported this research.

  2. 高温老化后HMX基PBX的压缩与拉伸性能反向变化研究%Reverse Change of Compressive and Tensile Properties of PBX Based on HMX Aged at High Temperature

    Institute of Scientific and Technical Information of China (English)

    温茂萍; 周红萍; 徐涛; 陈天娜; 庞海燕

    2011-01-01

    The mechanical properties of a polymer bonded explosive based on HMX thermally aged under 75 ℃ were investigated. The variation of the density of the samples is less than 0.003 g · Cm -3 before and after thermal aging. The results of the mechanical testing show that the compressive and tensile properties changed reversely after thermally treatment, that is, the compressive properties were decreased while the tensile properties were increased. Combined using the computer tomography ( piCT), X-ray photoelectron spectrometer (XPS) and ultrasonic microscope, it shows that the density decrease of the PBX maybe resulted from the volatilization of the lower-melting-point indigent of the formulation, that is the reason for the decrease of the compressive strength. Contrarily ,the interface bonding between the HMX crystals and the binder has been improved through the thermally aging such that the tensile mechanical properties as well as the tensile creep performance have been improved.%针对HMX基高聚物粘结炸药(HMX基PBX)经高温老化后虽然密度降低但是力学性能变化规律性不强的问题,将试样之间密度差控制在0.00 3g· cm-3范围内,经过不同时间75C高温老化后测试其力学性能变化.结果表明,HMX基PBX经过高温老化后,呈现出压缩性能降低而拉伸性能增强的反向变化现象.结合高精度X射线断层扫描(μCT)、超声显微、X光电子能谱(XPS)等检测结果对这一反向变化现象进一步分析,认为经过75℃高温老化后,由于HMX基PBX中低熔点组分挥发,密度降低,导致压缩性能降低,但在高温老化中,晶体损伤未明显增加,晶体与粘结剂界面作用增强,因此,受其影响较大的拉伸性能不但未降低,反而存在改善的趋势.

  3. The Los Alamos detonating pellet test (DPT): PBX 9501 evaluation tests

    International Nuclear Information System (INIS)

    High explosive (HE) Velocity of Detonation (VOD) measurements are usually conducted using rate-stick-type tests. This method is highly accurate if carefully implemented, but is relatively costly and may require kilograms or more of HE depending on its sensitivity. We present a novel technique for inferring VOD using a single HE pellet, which for Conventional High Explosives (CHEs) can use 10 gm of HE or even less. This attribute makes the Detonating Pellet Test (DPT) ideal for the preliminary performance characterization of newly synthesized HE materials. On the other end of the size spectrum, the DPT can be scaled to very large dimensions so as to minimize the HE load necessary to characterize highly insensitive HEs such as ANFO. The DPT exploits the fact that the detonation emerging from the pellet face can be made highly spherical over some central region. Spherical detonation breakout on the Sample Pellet (SP) face is described by a simple analytic equation, which depends on the VOD and the Center Of Initiation (COI). The latter is determined by separate characterization of the detonator, with a wave refraction correction at the detonator/SP interface. The SP VOD is then determined by fitting the ideal breakout equation, with specified detonator COI, to detonation breakout data obtained via streak camera. We develop the DPT method and appraise it using sample PBX 9501 data in particular, while discussing its benefits and limitations in general.

  4. Structural stability, vibrational, and bonding properties of potassium 1, 1′-dinitroamino-5, 5′-bistetrazolate: An emerging green primary explosive

    Energy Technology Data Exchange (ETDEWEB)

    Yedukondalu, N.; Vaitheeswaran, G., E-mail: gvsp@uohyd.ernet.in [Advanced Centre of Research in High Energy Materials (ACRHEM), University of Hyderabad, Prof. C. R. Rao Road, Gachibowli, Telangana State, Hyderabad 500 046 (India)

    2015-08-14

    Potassium 1,1′-dinitroamino-5,5′-bistetrazolate (K{sub 2}DNABT) is a nitrogen rich (50.3% by weight, K{sub 2}C{sub 2}N{sub 12}O{sub 4}) green primary explosive with high performance characteristics, namely, velocity of detonation (D = 8.33 km/s), detonation pressure (P = 31.7 GPa), and fast initiating power to replace existing toxic primaries. In the present work, we report density functional theory (DFT) calculations on structural, equation of state, vibrational spectra, electronic structure, and absorption spectra of K{sub 2}DNABT. We have discussed the influence of weak dispersive interactions on structural and vibrational properties through the DFT-D2 method. We find anisotropic compressibility behavior (bbonding suggests that the investigated compound is relatively stable and insensitive than covalent primaries. From the calculated absorption spectra, the material is found to decompose under ultra-violet light irradiation.

  5. Specimen size effect of explosive sensitivity under low velocity impact

    Science.gov (United States)

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

    2014-05-01

    Low velocity impact may ignite the solid high explosives and cause undesired explosion incidents. The safety of high explosives under low velocity impact is one of the most important issues in handling, manufacture, storage, and transportation procedures. Various evaluation tests have been developed for low velocity impact scenarios, including, but not limited to the drop hammer test, the Susan test, the Spigot test, and the Steven test, with a charge mass varying from tens of milligrams to several kilograms. The effects of specimen size on explosive sensitivity were found in some impact tests such as drop hammer test and Steven tests, including the threshold velocity/height and reaction violence. To analyse the specimen size effects on explosive sensitivity under low velocity impacts, we collected the impact sensitivity data of several PBX explosives in the drop hammer test, the Steven test, the Susan test and the Spigot test. The effective volume of explosive charge and the critical specific mechanical energy were introduced to investigate the size-effect on the explosive reaction thresholds. The effective volumes of explosive charge in Steven test and Spigot test were obtained by numerical simulation, due to the deformation localization of the impact loading. The critical specific mechanical energy is closely related to the effective volume of explosive charge. The results show that, with the increase of effective volume, the critical mechanical energy needed for explosive ignition decreases and tends to reach a constant value. The mechanisms of size effects on explosive sensitivity are also discussed.

  6. The role of Pbx1 in T cells

    Institute of Scientific and Technical Information of China (English)

    Mayami Sengupta; Laurence Morel

    2011-01-01

    Tissue and organ differentiation is tightly controlled to ensure proper development and function of the growing embryo as well as cells such as lymphocytes that differentiate throughout the adult stage.Therefore it is vital that the genes and the protein they encode that are involved in these processes function accurately.Hence,any mutation or error that occurs along the way can result in extensive damage,which is expressed in various ways in the embryo and can result in immune pathogenesis,including immunodeficiency and autoimmune diseases,when lymphocyte development is altered.A number of studies have been carried out to look at the genes regulating transcription in tissue differentiation,including the transcription factors Pbx1.This gene is of particular interest to us as we have identified that it is associated with systemic lupus erythematosus susceptibility (Cuda et al.,in press).This perspective summarizes the known roles of Pbx1 in tissue differentiation as well as our recent findings associating genetic variations in Pbx1 to lupus susceptibility,and we will speculate on how this gene controls the maintenance of immune tolerance in T cells.

  7. Testing and modeling of PBX-9591 shock initiation

    Energy Technology Data Exchange (ETDEWEB)

    Lam, Kim [Los Alamos National Laboratory; Foley, Timothy [Los Alamos National Laboratory; Novak, Alan [Los Alamos National Laboratory; Dickson, Peter [Los Alamos National Laboratory; Parker, Gary [Los Alamos National Laboratory

    2010-01-01

    This paper describes an ongoing effort to develop a detonation sensitivity test for PBX-9501 that is suitable for studying pristine and damaged HE. The approach involves testing and comparing the sensitivities of HE pressed to various densities and those of pre-damaged samples with similar porosities. The ultimate objectives are to understand the response of pre-damaged HE to shock impacts and to develop practical computational models for use in system analysis codes for HE safety studies. Computer simulation with the CTH shock physics code is used to aid the experimental design and analyze the test results. In the calculations, initiation and growth or failure of detonation are modeled with the empirical HVRB model. The historical LANL SSGT and LSGT were reviewed and it was determined that a new, modified gap test be developed to satisfy the current requirements. In the new test, the donor/spacer/acceptor assembly is placed in a holder that is designed to work with fixtures for pre-damaging the acceptor sample. CTH simulations were made of the gap test with PBX-9501 samples pressed to three different densities. The calculated sensitivities were validated by test observations. The agreement between the computed and experimental critical gap thicknesses, ranging from 9 to 21 mm under various test conditions, is well within 1 mm. These results show that the numerical modeling is a valuable complement to the experimental efforts in studying and understanding shock initiation of PBX-9501.

  8. Moiré interferometry studies of PBX9501

    Science.gov (United States)

    Rae, Philip; Goldrein, H. Timothy; Palmer, Stewart; Proud, William

    2001-06-01

    Moiré interferometry studies of PBX9501. P.J. Rae, H.T. Goldrein, S.J.P. Palmer, W.G. Proud Moiré interferometry is a sensitive technique for measuring in-plane displacements. Here, we measure one component of in-plane displacement with a spatial resolution of approximately 1 μm and a displacement sensitivity which can approach 10 nm. We have studied the deformation of real and mock PBX501 specimens in a variety of loading geometries. Specimens are polished and stained to reveal the microstructure, and a thin 1200 lines/mm phase grating is cast on its surface using a low-modulus epoxy resin. The specimen is illuminated symmetrically with two light beams from the same laser such that the first-order diffracted beams enter a camera system. As the specimen deforms, each extra fringe in the interference pattern represents 0.4 μm of surface displacement. Accurate interpolation between fringes gives high sensitivity. With a semi-transparent grating, it is possible to record white-light images of the specimen microstructure in exact registration with the displacements maps. Thus the influence of the microstructure on the strain distribution can be studied, allowing great insight into the failure mechanisms which may be at work. Applications to various PBX9501 specimens will be described.

  9. Pbx proteins cooperate with Engrailed to pattern the midbrain-hindbrain and diencephalic-mesencephalic boundaries.

    Science.gov (United States)

    Erickson, Timothy; Scholpp, Steffen; Brand, Michael; Moens, Cecilia B; Waskiewicz, Andrew Jan

    2007-01-15

    Pbx proteins are a family of TALE-class transcription factors that are well characterized as Hox co-factors acting to impart segmental identity to the hindbrain rhombomeres. However, no role for Pbx in establishing more anterior neural compartments has been demonstrated. Studies done in Drosophila show that Engrailed requires Exd (Pbx orthologue) for its biological activity. Here, we present evidence that zebrafish Pbx proteins cooperate with Engrailed to compartmentalize the midbrain by regulating the maintenance of the midbrain-hindbrain boundary (MHB) and the diencephalic-mesencephalic boundary (DMB). Embryos lacking Pbx function correctly initiate midbrain patterning, but fail to maintain eng2a, pax2a, fgf8, gbx2, and wnt1 expression at the MHB. Formation of the DMB is also defective as shown by a caudal expansion of diencephalic epha4a and pax6a expression into midbrain territory. These phenotypes are similar to the phenotype of an Engrailed loss-of-function embryo, supporting the hypothesis that Pbx and Engrailed act together on a common genetic pathway. Consistent with this model, we demonstrate that zebrafish Engrailed and Pbx interact in vitro and that this interaction is required for both the eng2a overexpression phenotype and Engrailed's role in patterning the MHB. Our data support a novel model of midbrain development in which Pbx and Engrailed proteins cooperatively pattern the mesencephalic region of the neural tube. PMID:16959235

  10. NOVEL APPROACH TO RESOLVE NETWORK SECURITY ISSUES IN IP-PBX IN CONVERGED ARCHITECTURE

    Directory of Open Access Journals (Sweden)

    MUNIR B. SAYYAD,

    2010-10-01

    Full Text Available This paper aims to examine the security issues in the IP-PBX (IP Private Branch Exchange .The Traces are taken on the live environment using Vendor ‘X’ CDMA MSC. The traces are also taken at SBC (Session Boarder Controller. The PBX services can be provided over IP via a SIP (session initiation protocol trunk provided by network operator. The SIP trunk is connected to a switch i.e. MSC. Thus IP connectivity is available at IP-PBX end. Now calls can be originated from IP-PBX which is terminating on a mobile handset registered with MSC. The problem arises when a dummy/blank/fake CLI (caller line identification is configured at IP-PBX. As MSC isdoing only part of routing depending upon called party number, such calls with fake CLI pass through MSC without any intervention. So called party and even MSC are unaware of real number of calling party. Similar security issue arises when IP-PBX sends dummy IP addresses of IP phones connected to IP-PBX. Thus conflict of IP addresses and or called party numbers creates a major security concern. These are important issues for interfacing IP with traditional wire line or wireless network. Such a security issue can be resolved by registering IP-PBX and its extension numbers with MSC. This paper describes the probable methods to resolve above issues.

  11. Primary explosives

    Energy Technology Data Exchange (ETDEWEB)

    Matyas, Robert; Pachman, Jiri [Pardubice Univ. (Czech Republic). Faculty of Chemical Technology

    2013-06-01

    The first chapter provides background such as the basics of initiation and differences between requirements on primary explosives used in detonators and igniters. The authors then clarify the influence of physical characteristics on explosive properties, focusing on those properties required for primary explosives. Furthermore, the issue of sensitivity is discussed. All the chapters on particular groups of primary explosives are structured in the same way, including introduction, physical and chemical properties, explosive properties, preparation and documented use.

  12. Research on the Specific Heat Capacity of PBX Formulations Based on RDX

    Directory of Open Access Journals (Sweden)

    Flávio Rodrigues Chaves

    2016-07-01

    Full Text Available The experimental results of specific heat capacity of 2 plastic bonded explosives formulations based on 1,3,5-trinitroperhydro-1,3,5-triazine, using differential scanning calorimetry thermal analysis, and the theoretical ones calculated with the specific heat capacity and mass fraction of individual compounds are compared for a temperature range between 340 and 410 K. Apart the filler, the plastic bonded explosives composition includes the binder based on hydroxyl-terminated polybutadiene, the plasticizer bis (2-ethylhexyl sebacate and the curing agent isophorone diisocyanate. The experimental and theoretical results showed a better approach when no curing agent is added. Without curing agent, the specific heat capacity of plastic bonded explosives increases linearly with temperature. When plastic bonded explosive is cured, the specific heat capacity is nearly constant until 380 K and decreases linearly for higher temperature values. These results suggest that phase change requires adjusting parameters to different heating rates in order to describe adequately the experimental data.

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

    Energy Technology Data Exchange (ETDEWEB)

    Reaugh, J E

    2011-11-22

    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

  14. Low amplitude impact testing and analysis of pristine and aged solid high explosives

    Energy Technology Data Exchange (ETDEWEB)

    Chidester, S K; Garza, R; Tarver, C M

    1998-08-17

    The critical impact velocities of 60.1 mm diameter blunt steel projectiles required for ignition of exothermic chemical reaction were determined for heavily confined charges of new and aged (15-30 years) solid HMX-based high explosives. The explosives in order of decreasing impact sensitivity were: PBX 9404; LX-lo; LX-14; PBX 9501; and LX-04. Embedded pressure gauges measured the interior pressure histories. Stockpile aged LX-04 and PBX 9501 from dismantled units were tested and compared to freshly pressed charges. The understanding of explosive aging on impact ignition and other hazards must improve as systems are being deployed longer than their initial estimated lifetimes. The charges that did not react on the first impact were subjected to multiple impacts. While the violence of reaction increased with impact velocity, it remained much lower than that produced by an intentional detonation. Ignition and Growth reactive flow models were developed to predict HMX-based explosive impact sensitivity in other geometries and scenarios.

  15. Mesoscale Probing of Local Perturbations in PBX-driven Liners

    Science.gov (United States)

    Plaksin, Igor; Guirguis, Raafat; Rodrigues, Luis; Mendes, Ricardo; Plaksin, Svyatoslav; ADAI, Univ of Coimbra; NSWC-IH Collaboration

    2013-06-01

    Efforts are aimed on experimental studies of how to improve a dynamic performance of the shaped charge jet. We postulated four basic elements to the problem: (1) The fluctuations in properties inherent in PBXs cause kinetic localizations in the detonation reaction zone (DRZ) structure, which cause (2) perturbations in the detonation products velocity and pressure, which induce (3) Perturbations in the response of the PBX-driven liner; and (4) Local perturbations/instabilities in liner are amplified during its collapse phase causing micro-fragmentations and ejected debris from the cumulative jet at initial stage, and then the incoherence and premature breakup of the resulting shaped charge jet. Spatially-resolved scenarios of each of phenomena (1-4) were obtained in experiments with copper-liners and HMX-based PBXs fabricated on maximum packing density of crystalline constituents, in which the DRZ-induced perturbations were recorded and quantitatively measured in the mesoscale range with application of the 96-channel optical analyzer MCOA-UC. Obtained experimental evidence is indicative that ejecta from the DRZ and ejecta-driven detonation cells are dominating in wide spectrum perturbations translated to a PBX-driven liner. This work was supported by the Office of Naval Research under the ONR and ONR Global Grants N00014-12-1-0477 and N62909-12-1-7131 with Drs. Clifford Bedford and Shawn Thorne Program Managers.

  16. PBX 9502 Stockpile-Returned Hemi Tension Directionality Study

    Energy Technology Data Exchange (ETDEWEB)

    Gagliadi, F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pease, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Cunningham, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-02-23

    This work is a continuation of work started in FY12 to evaluate whether the coring direction in PBX 9502 main charges affects the mechanical properties data. In FY13 we performed the compression and thermal expansion portions of the testing.1 In FY14 we have performed the quasi-static tension and compressive creep parts of the study. This paper focuses on the tensile results while a companion paper details the compressive creep results.2 In an effort to obtain mechanical properties samples that would better characterize the density distribution within a main charge and, to a lesser extent, to more thoroughly describe the mechanical behavior of material that has been in the field for long period of time, the LLNL PBX 9502 Core Surveillance coring pattern had been changed between cycles 29 and 30. Where the orientation of the tensile and compression samples tested in surveillance prior to cycle 30 had been cored in the tangential direction, the new coring diagram has both the tension and compression samples being oriented in the hoop direction. Prior to this study, the authors were not aware of any work that systematically demonstrated the effect on tensile properties of samples cored in these distinct directions. The results from this study will inform us of if and how we should trend the data taken before and after the coring pattern change.

  17. Dead Zones in LX-17 and PBX 9502

    Energy Technology Data Exchange (ETDEWEB)

    Souers, P C; Andreski, H G; Batteux, J; Bratton, B; Cabacungan, C; Cook, III, C F; Fletcher, S; Garza, R; Grimsley, D; Handly, J; Hernandez, A; McMaster, P; Molitoris, J D; Palmer, R; Prindiville, J; Rodriguez, J; Schneberk, D; Wong, B; Vitello, P

    2005-09-06

    Pin and X-ray corner-turning data have been taken on ambient LX-17 and PBX 9052, and the results are listed in tables as an aid to future modeling. The results have been modeled at 4 zones/mm with a reactive flow approach that varies the burn rate as a function of pressure. A single rate format is used to simulate failure and detonation in different pressure regimes. A pressure cut-off must also be reached to initiate the burn. Corner-turning and failure are modeled using an intermediate pressure rate region, and detonation occurs at high pressure. The TATB booster is also modeled using reactive flow, and X-ray tomography is used to partition the ram-pressed hemisphere into five different density regions. The model reasonably fits the bare corner-turning experiment but predicts a smaller dead zone with steel confinement, in contradiction with experiment. The same model also calculates the confined and unconfined cylinder detonation velocities and predicts the failure of the unconfined cylinder at 3.75 mm radius. The PBX 9502 shows a smaller dead zone than LX-17. An old experiment that showed a large apparent dead zone in Comp B was repeated with X-ray transmission and no dead zone was seen. This confirms the idea that a variable burn rate is the key to modeling. The model also produces initiation delays, which are shorter than those found in time-to-detonation.

  18. A Strength Model and Service Envelope for PBX 9501

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-02-05

    An analytical method is proposed for making an assessment of the severity of the response of PBX 9501 in structural response simulations. The approach is based on the coherent use of a strength model and a failure criterion. The strength model is based on a creep rupture function and an associated cumulative damage model. The material's residual strength at any time during a simulation of structural response is determined by taking into account both the actual stress history up to that time, and a hypothetical continuation of the applied stresses that are assumed to grow until material failure results. The residual strength is used by the failure criterion to define the region of safe (non-failed) material response. The Mohr-Coulomb failure criterion is chosen for its general applicability to materials with both cohesive and frictional strength. The combined use of the residual strength model and the failure criterion provides a quantitative method of assessing the severity of the response of PBX 9501 material in structural simulations: the proximity of any evolving, general state of stress to the failure surface (which shrinks due to the cumulative damage caused by the past stress history) can be calculated and used as a measure of margin to failure. The strength model has been calibrated to a broad range of uniaxial tension and compression tests, and a small set of creep tests, and is applicable to a broad range of loading conditions.

  19. Measurement of Low Level Explosives Reaction in Gauged Multi-Dimensional Steven Impact Tests

    Energy Technology Data Exchange (ETDEWEB)

    Niles, A M; Garcia, F; Greenwood, D W; Forbes, J W; Tarver, C M; Chidester, S K; Garza, R G; Swizter, L L

    2001-05-31

    The Steven Test was developed to determine relative impact sensitivity of metal encased solid high explosives and also be amenable to two-dimensional modeling. Low level reaction thresholds occur at impact velocities below those required for shock initiation. To assist in understanding this test, multi-dimensional gauge techniques utilizing carbon foil and carbon resistor gauges were used to measure pressure and event times. Carbon resistor gauges indicated late time low level reactions 200-540 {micro}s after projectile impact, creating 0.39-2.00 kb peak shocks centered in PBX 9501 explosives discs and a 0.60 kb peak shock in a LX-04 disk. Steven Test modeling results, based on ignition and growth criteria, are presented for two PBX 9501 scenarios: one with projectile impact velocity just under threshold (51 m/s) and one with projectile impact velocity just over threshold (55 m/s). Modeling results are presented and compared to experimental data.

  20. Plane impact response of PBX 9501 and its components below 2 GPa

    Energy Technology Data Exchange (ETDEWEB)

    Dick, J.J.; Martinez, A.R.; Hixson, R.S.

    1998-04-01

    The Hugoniot equation of state was measured for PBX 9501, the binder, and estane below 2 GPa using a light-gas gun facility. Time-resolved wave profiles were also obtained for these materials as well as for HMX single crystals in a state of uniaxial strain. The dynamic strength of PBX 9501 was measured at high strain rates in both compression and tension. In addition, elastic moduli were obtained from measurements of longitudinal and shear sound speeds.

  1. Non-ideal detonation behaviour of PBX 9502

    Science.gov (United States)

    Schoch, Stefan; Nikiforakis, Nikos

    2009-06-01

    Numerical experiments are performed investigating the non-ideal detonation behaviour of PBX 9502 in two setups. In the first setup we consider a three-dimensional rate stick experiment. A booster charge initiates a reaction front leading to a curved detonation wave. The numerical results are compared to theory and experimental evidence. The effects of weak and strong confinement are discussed. The second setup considers the so called ``hockey puck experiment.'' Experimental results show the appearance of a dead zone due to the effect of the geometry. This is captured by the numerical results, which also reveal that the initially spherical detonation is diffracted leading to local detonation failure. The numerical simulations are performed by solving a mathematical model for a three-phase medium based on the Euler equations. The numerical results are obtained using high-resolution shock-capturing methods combined with adaptive mesh refinement.

  2. PBX炸药声共振混合试验研究Ⅰ❋%Experimental Study on Resonance Acoustic Mixing of PBX ExplosiveⅠ

    Institute of Scientific and Technical Information of China (English)

    马宁; 秦能; 蒋浩龙; 张哲; 孙晓朋; 陈松

    2016-01-01

    An experimental study on the mixing uniformity and process safety of resonance acoustic mixing ( RAM) of PBX explosive with 86% solid mass fraction was carried out by RAM experimental prototype, and the sample scale was 150 g. Experimental results show that the PBX explosive is involved in tanglement and tear in the mixture, followed by the for-mation of a spherical mixed block and blended pastes in turn, and the total mixing time is about 1 000 s. Component analy-sis of mixture shows that the RAM could realize uniformly mixing of PBX explosive. Electrostatic and temperature measure-ments show that the electrostatic voltage is almost 0 through the mixing process, and friction heating rate is slower than heat dissipation rate. Electrostatic and thermal risk is within a controllable range.%通过声共振混合试验样机对固体质量分数为86%的PBX炸药(高聚物黏结炸药)进行声共振混合的均匀性及工艺安全性试验研究,试验量级为150 g。试验结果表明,PBX炸药在声共振混合作用下进行内部的撕裂缠结,依次形成球状混合块和整场沸腾状混合浆,整个混合时间约为1000 s。成分分析表明,声共振能实现固体质量分数为86%的PBX炸药均匀混合;静电和温度测量表明,整个混合过程中,静电电压几乎维持在0 kV左右,物料内部摩擦生热速度远远低于物料对外的热散失速度,混合过程中静电安全和热安全在可控范围内。

  3. The analytic hierarchy process as a framework for sourcing decisions: management, operations, and maintenance of a PBX

    OpenAIRE

    Bowens, Desobry E.

    2000-01-01

    With the installation of a new Private Branch Exchange (PBX), a telephone switch system, the Naval Postgraduate School is looking for the most effective method of sourcing the management, operations, and maintenance functions of the switch system. This thesis examines other organizations that operate a PBX in a campus-like environment. Using the data from these organizations, this thesis creates a decision framework for the NPS PBX sourcing decision using the Analytic Hierarchy Process (AHP)....

  4. Detection of E2A-PBX1 fusion transcripts in human non-small-cell lung cancer

    OpenAIRE

    Mo, Min-Li; Chen, Zhao; Zhou, Hai-Meng; LI Hui; Hirata, Tomomi; Jablons, David M; He, Biao

    2013-01-01

    Background E2A-PBX1 fusion gene caused by t(1;19)(q23;p13), has been well characterized in acute lymphoid leukemia (ALL). There is no report on E2A-PBX1 fusion transcripts in non-small-cell lung cancer (NSCLC). Methods We used polymerase chain reaction (PCR) to detect E2A-PBX1 fusion transcripts in human NSCLC tissue specimens and cell lines. We analyzed correlation of E2A-PBX1 fusion transcripts with clinical outcomes in 76 patients with adenocarcinoma in situ (AIS) and other subgroups. We c...

  5. Investigation of aluminum-steel joint formed by explosion welding

    Science.gov (United States)

    Kovacs-Coskun, T.; Volgyi, B.; Sikari-Nagl, I.

    2015-04-01

    Explosion welding is a solid state welding process that is used for the metallurgical joining of metals. Explosion cladding can be used to join a wide variety of dissimilar or similar metals [1]. This process uses the controlled detonation of explosives to accelerate one or both of the constituent metals into each other in such a manner as to cause the collision to fuse them together [2]. In this study, bonding ability of aluminum and steel with explosion welding was investigated. Experimental studies, microscopy, microhardness, tensile and bend test showed out that, aluminum and steel could be bonded with a good quality of bonding properties with explosion welding.

  6. PBX/extradenticle is required to re-establish axial structures and polarity during planarian regeneration.

    Science.gov (United States)

    Blassberg, Robert A; Felix, Daniel A; Tejada-Romero, Belen; Aboobaker, A Aziz

    2013-02-01

    Recent advances in a number of systems suggest many genes involved in orchestrating regeneration are redeployed from similar processes in development, with others being novel to the regeneration process in particular lineages. Of particular importance will be understanding the architecture of regenerative genetic regulatory networks and whether they are conserved across broad phylogenetic distances. Here, we describe the role of the conserved TALE class protein PBX/Extradenticle in planarians, a representative member of the Lophotrocozoa. PBX/Extradenticle proteins play central roles in both embryonic and post-embryonic developmental patterning in both vertebrates and insects, and we demonstrate a broad requirement during planarian regeneration. We observe that Smed-pbx has pleiotropic functions during regeneration, with a primary role in patterning the anterior-posterior (AP) axis and AP polarity. Smed-pbx is required for expression of polarity determinants notum and wnt1 and for correct patterning of the structures polarized along the AP axis, such as the brain, pharynx and gut. Overall, our data suggest that Smed-pbx functions as a central integrator of positional information to drive patterning of regeneration along the body axis. PMID:23318635

  7. Biochemistry of the tale transcription factors PREP, MEIS, and PBX in vertebrates.

    Science.gov (United States)

    Longobardi, E; Penkov, D; Mateos, D; De Florian, G; Torres, M; Blasi, Francesco

    2014-01-01

    TALE (three amino acids loop extension) homeodomain transcription factors are required in various steps of embryo development, in many adult physiological functions, and are involved in important pathologies. This review focuses on the PREP, MEIS, and PBX sub-families of TALE factors and aims at giving information on their biochemical properties, i.e., structure, interactors, and interaction surfaces. Members of the three sets of protein form dimers in which the common partner is PBX but they can also directly interact with other proteins forming higher-order complexes, in particular HOX. Finally, recent advances in determining the genome-wide DNA-binding sites of PREP1, MEIS1, and PBX1, and their partial correspondence with the binding sites of some HOX proteins, are reviewed. These studies have generated a few general rules that can be applied to all members of the three gene families. PREP and MEIS recognize slightly different consensus sequences: PREP prefers to bind to promoters and to have PBX as a DNA-binding partner; MEIS prefers HOX as partner, and both PREP and MEIS drive PBX to their own binding sites. This outlines the clear individuality of the PREP and MEIS proteins, the former mostly devoted to basic cellular functions, the latter more to developmental functions.

  8. The Lupus Susceptibility Gene Pbx1 Regulates the Balance between Follicular Helper T Cell and Regulatory T Cell Differentiation.

    Science.gov (United States)

    Choi, Seung-Chul; Hutchinson, Tarun E; Titov, Anton A; Seay, Howard R; Li, Shiwu; Brusko, Todd M; Croker, Byron P; Salek-Ardakani, Shahram; Morel, Laurence

    2016-07-15

    Pbx1 controls chromatin accessibility to a large number of genes and is entirely conserved between mice and humans. The Pbx1-d dominant-negative isoform is more frequent in CD4(+) T cells from lupus patients than from healthy controls. Pbx1-d is associated with the production of autoreactive T cells in mice carrying the Sle1a1 lupus-susceptibility locus. Transgenic (Tg) expression of Pbx1-d in CD4(+) T cells reproduced the phenotypes of Sle1a1 mice, with increased inflammatory functions of CD4(+) T cells and impaired Foxp3(+) regulatory T cell (Treg) homeostasis. Pbx1-d-Tg expression also expanded the number of follicular helper T cells (TFHs) in a cell-intrinsic and Ag-specific manner, which was enhanced in recall responses and resulted in Th1-biased Abs. Moreover, Pbx1-d-Tg CD4(+) T cells upregulated the expression of miR-10a, miR-21, and miR-155, which were implicated in Treg and follicular helper T cell homeostasis. Our results suggest that Pbx1-d impacts lupus development by regulating effector T cell differentiation and promoting TFHs at the expense of Tregs. In addition, our results identify Pbx1 as a novel regulator of CD4(+) T cell effector function. PMID:27296664

  9. PBX 9501 Outgas Analysis by SPME/GC/MS

    Energy Technology Data Exchange (ETDEWEB)

    Chambers, D.M.

    2000-12-11

    The authors used equilibrium headspace gas chromatography/mass spectrometry (GC/MS) to monitor volatile and semivolate species that are expected to migrate through PBX 9501 under environmentally relevant conditions. In this work they screened 11 samples taken from deployed parts. Although a number of chemical permeates were identified, the antioxidant signature provided the most information with regard to decomposition aging. Specifically, they were able to monitor butylated hydroxytoluene (BHT) and other antioxidants, which are apparently added to either the Estane adipate or MDI precursor by the manufacturer. They found that in those parts where diphenylamine (DPA) was used as a stabilizer, BHT response was significantly lower than in those formulations stabilized with Irganox 1010 (Irganox). These results imply that DPA is less efficient as a radical scavenger than Irganox. This lower efficiency might be related to the lack of oxygen in the weapon environment, which is initially < 0.1%. With regard to DPA, it has been reported that radical scavenging activity is proportional to the oxygen pressure. At this time they are uncertain whether the low DPA efficiency is mainly attributed to the oxygen level or if there is another rate limiting step that would lead to the preferential consumption of BHT.

  10. Cellular Structure and Oscillating Behavior of PBX Detonations

    Science.gov (United States)

    Plaksin, Igor; Rodrigues, Luis; Mendes, Ricardo; Plaksin, Svyatoslav; Ferreira, Claudia; Fernandes, Eduardo

    2015-06-01

    Efforts are aimed on experimental study of reaction localization/instabilities manifested in detonation reaction zone (DRZ) of PBXs at micro-, meso- and macro-scale. At micro- and meso-scale levels, leading role of kinetic nonequilibrium in reaction localizations onset was established in experiments with single beta-HMX crystals-in-binder subjected to 20 GPa-shock and PBX detonation. Reaction localizations and further ejecta formation were spatially resolved by 96-channel optical analyzer at simultaneous recording reaction light and stress field around crystal. Spatially resolved measurements reveal fundamental role of shear-strain in triggering initiation chemistry. At macro-scale level, formation of the cell-structures and oscillating detonation regimes revealed in HMX- and RDX-based PBXs at wide variation of grain-sizes, wt. % filler/binder, residual micro-voids and binder nature. Emphasizes placed on effect of DRZ-induced radiation upon oscillating regimes of detonation front motion. Work was supported by the ONR and ONR Global Grants N00014-12-1-0477 and N62909-12-1-7131 with Drs. Clifford Bedford and John Zimmerman Program Managers.

  11. Some analytical methods for explosives: Part 2

    Energy Technology Data Exchange (ETDEWEB)

    Selig, W.

    1965-12-08

    This report is the second compilation of methods for analyzing explosives. All the methods were developed for routine performance by techniques, and an attempt has therefore been made to keep them as simple as possible. Methods are presented for analyzing plastic-bonded explosives based on sym-cyclomethylenetetra-nitramine (HMX), based on viton in addition to HMX, and based on pentraerythritol tetranitrate (PETN).

  12. Computed tomography experiments of Pantex high explosives

    Science.gov (United States)

    Perkins, D. E.; Martz, H. E.; Hester, L. O.; Sobczak, G.; Pratt, C. L.

    1992-04-01

    X-ray computed tomography is an advanced imaging technique which provide three-dimensional nondestructive characterization of materials, components and assemblies. The CT Project group at Lawrence Livermore National Laboratory (LLNL) and the Pantex Plant are cooperating to examine the use of CT technology to inspect and characterize high-explosives pressings (e.g., PBX-9502, LX-10-2). High-explosives pressings manufactured by Pantex must be characterized prior to assembling into weapons systems; a nondestructive examination of all assembly parts would be preferable to the current sampling and destructive testing. The earlier in the processing cycle this can be done the more cost effective it will be. We have performed experiments that show that this characterization can be performed at the pressed billet stage using CT. We have detected 2-mm inclusions in a 15-cm diameter billet and 3.5-mm voids in a 20-cm diameter billet. Based on these results we show calculations that can be used to design production CT systems for characterization of high-explosives.

  13. Comparative genomics reveals multistep pathogenesis of E2A-PBX1 acute lymphoblastic leukemia

    Science.gov (United States)

    Duque-Afonso, Jesús; Feng, Jue; Scherer, Florian; Lin, Chiou-Hong; Wong, Stephen H.K.; Wang, Zhong; Iwasaki, Masayuki; Cleary, Michael L.

    2015-01-01

    Acute lymphoblastic leukemia (ALL) is the most common childhood cancer; however, its genetic diversity limits investigation into the molecular pathogenesis of disease and development of therapeutic strategies. Here, we engineered mice that conditionally express the E2A-PBX1 fusion oncogene, which results from chromosomal translocation t(1;19) and is present in 5% to 7% of pediatric ALL cases. The incidence of leukemia in these mice varied from 5% to 50%, dependent on the Cre-driving promoter (Cd19, Mb1, or Mx1) used to induce E2A-PBX1 expression. Two distinct but highly similar subtypes of B cell precursor ALLs that differed by their pre–B cell receptor (pre-BCR) status were induced and displayed maturation arrest at the pro-B/large pre–B II stages of differentiation, similar to human E2A-PBX1 ALL. Somatic activation of E2A-PBX1 in B cell progenitors enhanced self-renewal and led to acquisition of multiple secondary genomic aberrations, including prominent spontaneous loss of Pax5. In preleukemic mice, conditional Pax5 deletion cooperated with E2A-PBX1 to expand progenitor B cell subpopulations, increasing penetrance and shortening leukemia latency. Recurrent secondary activating mutations were detected in key signaling pathways, most notably JAK/STAT, that leukemia cells require for proliferation. These data support conditional E2A-PBX1 mice as a model of human ALL and suggest targeting pre-BCR signaling and JAK kinases as potential therapeutic strategies. PMID:26301816

  14. Proton Radiography of Shape Charge Jets Penetrating Teflon and Explosive

    Science.gov (United States)

    Ferm, Eric N.; Burkett, Michael W.; Hull, Larry M.; Marr-Lyon, Mark; McNeil, Wendy V.; Morris, Chris L.; Rightley, Paul M.; Lansce Proton Radiography Team

    2011-06-01

    We have used proton radiography at the Los Alamos Neutron Science Center to observe viper shaped charge jets penetrating inert and explosive materials. A viper jet was observed penetrating both Teflon and PBX 9501. Radiographs captured the penetration events at several times and are analyzed to determine the density of the materials imaged at each time. The interfaces and shock waves in the flow are clearly evident in the images. Multiple time images allow the determination of the velocities of the interfaces and shock waves. Comparisons are made in the Teflon case with estimates of penetration rates and densities using the quasi-steady approximation analysis used in many terminal ballistics models. The PBX 9501 clearly detonated from the impact of the shape charge jet tip traveling at 9.1 mm/s. The detonation wave is examined to see what support it obtains from the pursing jet and the jet is examined to find the influence of the explosive products on penetration velocity. This experiment gives us experimental results of in-situ penetration process that can be used to verify common modeling techniques and fluid mechanic calculations of the penetration process.

  15. Fusion with E2A converts the Pbx1 homeodomain protein into a constitutive transcriptional activator in human leukemias carrying the t(1;19) translocation.

    OpenAIRE

    Lu, Q.; Wright, D D; Kamps, M P

    1994-01-01

    E2A-PBX1 is a chimeric gene formed by the t(1;19)(q23;p13.3) chromosomal translocation of pediatric pre-B-cell leukemia. The E2A-Pbx1 fusion protein contains sequences encoding the transactivation domain of E2A joined to a majority of the Pbx1 protein, which contains a novel homeodomain. Earlier, we found that expression of E2A-Pbx1 causes malignant transformation of NIH 3T3 fibroblasts and induces myeloid leukemia in mice. Here we demonstrate that the homeodomains encoded by PBX1, as well as...

  16. Physical properties of conventional explosives deduced from radio frequency emissions

    Energy Technology Data Exchange (ETDEWEB)

    Harlin, Jeremiah D [Los Alamos National Laboratory; Nemzek, Robert [Los Alamos National Laboratory

    2008-01-01

    Los Alamos National Laboratory collected broadband radio frequency (RF) electric field change measurements from multiple detonations of high explosives (HE). Three types of HE were used: small cylinders of flake TNT, solid TNT, and PBX-9501. Low frequency signals (<80 MHz) were shot-to-shot repeatable and occurred within the first 100 {mu} s at measured amplitudes of about 2 V m{sup -1} at 35 m distance. High frequency signals (>290 MHz) occurred later, were an order of magnitude lower in signal strength, and were not repeatable. There is a positive correlation between the maximum electric field change and the shock velocity of the HE. The amount of free charge produced in the explosion estimated from the first RF pulse is between 10 and 150 {mu} C. This implies a weakly ionized plasma with temperatures between 2600 and 2900 K.

  17. Explosive laser

    International Nuclear Information System (INIS)

    This patent relates to a laser system wherein reaction products from the detonation of a condensed explosive expand to form a gaseous medium with low translational temperature but high vibration population. Thermal pumping of the upper laser level and de-excitation of the lower laser level occur during the expansion, resulting in a population inversion. The expansion may be free or through a nozzle as in a gas-dynamic configuration. In one preferred embodiment, the explosive is such that its reaction products are CO2 and other species that are beneficial or at least benign to CO2 lasing

  18. Explosive complexes

    Science.gov (United States)

    Huynh, My Hang V.

    2009-09-22

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

  19. Niche explosion.

    Science.gov (United States)

    Normark, Benjamin B; Johnson, Norman A

    2011-05-01

    The following syndrome of features occurs in several groups of phytophagous insects: (1) wingless females, (2) dispersal by larvae, (3) woody hosts, (4) extreme polyphagy, (5) high abundance, resulting in status as economic pests, (6) invasiveness, and (7) obligate parthenogenesis in some populations. If extreme polyphagy is defined as feeding on 20 or more families of hostplants, this syndrome is found convergently in several species of bagworm moths, tussock moths, root weevils, and 5 families of scale insects. We hypothesize that extreme polyphagy in these taxa results from "niche explosion", a positive feedback loop connecting large population size to broad host range. The niche explosion has a demographic component (sometimes called the "amplification effect" in studies of pathogens) as well as a population-genetic component, due mainly to the increased effectiveness of natural selection in larger populations. The frequent origins of parthenogenesis in extreme polyphages are, in our interpretation, a consequence of this increased effectiveness of natural selection and consequent reduced importance of sexuality. The niche explosion hypothesis makes detailed predictions about the comparative genomics and population genetics of extreme polyphages and related specialists. It has a number of potentially important implications, including an explanation for the lack of observed trade-offs between generalists and specialists, a re-interpretation of the ecological correlates of parthenogenesis, and a general expectation that Malthusian population explosions may be amplified by Darwinian effects.

  20. Understanding and Predicting the Thermal Explosion Violence of HMX-Based and RDX-Based Explosives - Experimental Measurements of Material Properties and Reaction Violence

    Energy Technology Data Exchange (ETDEWEB)

    Maienschein, J L; Wardell, J F; Weese, R K; Cunningham, B J; Tran, T D

    2002-07-03

    The violence of thermal explosions with energetic materials is affected by many material properties, including mechanical and thermal properties, thermal ignition kinetics, and deflagration behavior. These properties must be characterized for heated samples as well as pristine materials. We present available data for these properties for two HMX-based formulations--LX-04 and PBX-9501, and two RDX-based formulations--Composition B and PBXN-109. We draw upon separately published data on the thermal explosion violence with these materials to compare the material properties with the observed violence. We have the most extensive data on deflagration behavior of these four formulations, and we discuss the correlation of the deflagration data with the violence results. The data reported here may also be used to develop models for application in simulation codes such as ALE3D to calculate and Dredict thermal explosion violence.

  1. 78 FR 64246 - Commerce in Explosives; List of Explosives Materials

    Science.gov (United States)

    2013-10-28

    ... isomorphously substituted inorganic salts. *ANFO . Aromatic nitro-compound explosive mixtures. Azide explosives.... Explosive mixtures containing tetranitromethane (nitroform). Explosive nitro compounds of aromatic... polyhydric alcohol explosives. Nitric acid and a nitro aromatic compound explosive. Nitric acid...

  2. A verification and validation effort for high explosives at Los Alamos National Lab (u)

    Energy Technology Data Exchange (ETDEWEB)

    Scovel, Christina A [Los Alamos National Laboratory; Menikoff, Ralph S [Los Alamos National Laboratory

    2009-01-01

    We have started a project to verify and validate ASC codes used to simulate detonation waves in high explosives. Since there are no non-trivial analytic solutions, we are going to compare simulated results with experimental data that cover a wide range of explosive phenomena. The intent is to compare both different codes and different high explosives (HE) models. The first step is to test the products equation of state used for the HE models, For this purpose, the cylinder test, flyer plate and plate-push experiments are being used. These experiments sample different regimes in thermodynamic phase space: the CJ isentrope for the cylinder tests, the isentrope behind an overdriven detonation wave for the flyer plate experiment, and expansion following a reflected CJ detonation for the plate-push experiment, which is sensitive to the Gruneisen coefficient. The results of our findings for PBX 9501 are presented here.

  3. Leidenfrost explosions

    CERN Document Server

    Moreau, F; Dorbolo, S

    2012-01-01

    We present a fluid dynamics video showing the behavior of Leidenfrost droplets composed by a mixture of water and surfactant (SDS, Sodium Dodecyl sulfate). When a droplet is released on a plate heated above a given temperature a thin layer of vapor isolates the droplet from the plate. The droplet levitates over the plate. This is called the Leidenfrost effect. In this work we study the influence of the addition of a surfactant on the Leidenfrost phenomenon. As the droplet evaporates the concentration of SDS rises up to two orders of magnitude over the Critical Micelle Concentration (CMC). An unexpected and violent explosive behavior is observed. The video presents several explosions taken with a high speed camera (IDT-N4 at 30000 fps). All the presented experiments were performed on a plate heated at 300{\\deg}C. On the other hand, the initial quantity of SDS was tuned in two ways: (i) by varying the initial concentration of SDS and (ii) by varying the initial size of the droplet. By measuring the volume of th...

  4. MHD activity and energy loss during beta saturation and collapse at high beta poloidal in PBX

    International Nuclear Information System (INIS)

    High-β experiments, in medium to high-q tokamak plasmas, exhibit a temporal β saturation and collapse. This behavior has been attributed to ballooning, ideal kink, or tearing modes. In PBX, a unique diagnostic capability allowed studies of the relation between MHD and energy loss for neutral-beam-heated (<6 MW), mildly indented (10 to 15%), nearly steady I/sub p/ discharges that approached the Troyon-Gruber limit. Under these conditions, correlations between MHD activity and energy losses have shown that the latter can be almost fully accounted for by various long wavelength MHD instabilities and that there is no need to invoke high-n ballooning modes in PBX. 6 refs., 4 figs

  5. 钙钛矿型复合铁氧体La1-xPbxFeO3纳米颗粒体系的结构研究%Structure of the Perovskite-type Complex Ferrites La1-xPbxFeO3 Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    张爱君

    2015-01-01

    采用溶胶凝胶法成功制备了La1-x Pbx FeO3( x=0,0.15,0.33)和不同颗粒尺寸的La0.67 Pb0.33 FeO3纳米颗粒.通过X射线衍射和Rietveld法对所有样品的晶体结构进行了系统研究.结果发现,所有样品均具有正交钙钛矿结构,空间群为D162h -Pbnm, La3+(Pb2+)和O2-离子都偏离了理想的立方钙钛矿结构中的位置,围绕着Fe离子的氧八面体发生畸变.Pb含量和颗粒尺寸的增加,均导致Fe-O键长减小,Fe-O-Fe键角增加.%La1-xPbxFeO3(x=0.0.15 and 0.33) nanoparticles and La0.67Pb0.33FeO3 nanoparticles with different particle sizes were prepared by a sol-gel method. Crystal structure was checked by X-ray diffraction and refined by Rietveld method. The results indicate that all samples crystallized in orthorhombic structure and with the space group of D162h-Pbnm, The La3+( Pb2+) ions and O2-ions are displaced from the ideal cubic positions. The oxygen octahedral surrounding the Fe ions are distorted. Both the increasing Pb level and the increasing particle size result in a decrease in Fe-O bond length and an increase in Fe-O-Fe bond angle.

  6. Safety assessment document (SAD) for the Princeton Beta Experiment Modification (PBX-M)

    Energy Technology Data Exchange (ETDEWEB)

    Stencel, J.R.; Parsells, R.F. (eds.)

    1988-04-01

    The Princeton Beta Experiment-Modification (PBX-M) is an experimental device of the tokamak type. A tokamak is characterized by a strong toroidal magnetic field composed of an externally driven component parallel to the torus centerline modified by the field produced by a transformer-driven current (OH) in the confined plasma. A second magnetic field parallel to the major toroidal axis is added to provide radial equilibrium for the plasma. As an advanced tokamak, PBX-M will have additional magnetic fields to reshape the plasma cross section from a circle into a kidney bean shape; it will also be equipped with 6MW or more of auxiliary heating power provided by four neutral beam injectors, with RF systems, and with an extensive set of diagnostics. Potential hazards associated with PBX-M, which are analyzed in this report, result from energy stored in the magnetic fields, high voltages necessary for the operation of some of the equipment and diagnostics, neutron radiation when the neutral beams are run with deuterium and x-rays, especially those emitted as a result of plasma-wall interaction. This report satisfies the requirements set forth in the PPPL Health and Safety Directives, specifically HSD-5003, and in DOE Order 5481.1B and its Chicago operations supplement (DOE86, DOE82).

  7. Diagnostics for real-time plasma control in PBX-M

    Science.gov (United States)

    Kaita, R.; Batha, S.; Bell, R. E.; Bernabei, S.; Hatcher, R.; Kozub, T.; Kugel, H.; Levinton, F.; Okabayashi, M.; Sesnic, S.; von Goeler, S.; Zolfaghari, A.; PBX-M Group

    1995-01-01

    An important issue for future tokamaks is real-time plasma control for the avoidance of magnetohydrodynamic instabilities and other applications that require detailed plasma profile and fluctuation data. Although measurements from diagnostics providing this information require significantly more processing than magnetic flux data, recent advancements could make them practical for adjusting operational settings for plasma heating and current drive systems as well as field coil currents. On the Princeton Beta Experiment-Modification (PBX-M), the lower hybrid current drive phasing can be varied during a plasma shot using digitally programmable ferrite phase shifters, and neural beam functions can be fully computer controlled. PBX-M diagnostics that may be used for control purposes include motional Stark-effect polarimetry for magnetic field pitch angle profiles, soft x-ray arrays for plasma position control and the separation of βp from li, hard x-ray detectors for energetic electron distributions, a multichannel electron cyclotron emission radiometer for ballooning mode identification, and passive plate eddy current monitors for kink stabilization. We will describe the present status of these systems on PBX-M, and discuss their suitability for feedback applications.

  8. Safety assessment document (SAD) for the Princeton Beta Experiment Modification (PBX-M)

    International Nuclear Information System (INIS)

    The Princeton Beta Experiment-Modification (PBX-M) is an experimental device of the tokamak type. A tokamak is characterized by a strong toroidal magnetic field composed of an externally driven component parallel to the torus centerline modified by the field produced by a transformer-driven current (OH) in the confined plasma. A second magnetic field parallel to the major toroidal axis is added to provide radial equilibrium for the plasma. As an advanced tokamak, PBX-M will have additional magnetic fields to reshape the plasma cross section from a circle into a kidney bean shape; it will also be equipped with 6MW or more of auxiliary heating power provided by four neutral beam injectors, with RF systems, and with an extensive set of diagnostics. Potential hazards associated with PBX-M, which are analyzed in this report, result from energy stored in the magnetic fields, high voltages necessary for the operation of some of the equipment and diagnostics, neutron radiation when the neutral beams are run with deuterium and x-rays, especially those emitted as a result of plasma-wall interaction. This report satisfies the requirements set forth in the PPPL Health and Safety Directives, specifically HSD-5003, and in DOE Order 5481.1B and its Chicago operations supplement (DOE86, DOE82)

  9. Chaotic Explosions

    CERN Document Server

    Altmann, Eduardo G; Tél, Tamás

    2015-01-01

    We investigate chaotic dynamical systems for which the intensity of trajectories might grow unlimited in time. We show that (i) the intensity grows exponentially in time and is distributed spatially according to a fractal measure with an information dimension smaller than that of the phase space,(ii) such exploding cases can be described by an operator formalism similar to the one applied to chaotic systems with absorption (decaying intensities), but (iii) the invariant quantities characterizing explosion and absorption are typically not directly related to each other, e.g., the decay rate and fractal dimensions of absorbing maps typically differ from the ones computed in the corresponding inverse (exploding) maps. We illustrate our general results through numerical simulation in the cardioid billiard mimicking a lasing optical cavity, and through analytical calculations in the baker map.

  10. Extrusion cast explosive

    Science.gov (United States)

    Scribner, Kenneth J.

    1985-01-01

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

  11. Chemical profiling of explosives

    NARCIS (Netherlands)

    G.M.H. Brust

    2014-01-01

    The primary goal of this thesis is to develop analytical methods for the chemical profiling of explosives. Current methodologies for the forensic analysis of explosives focus on identification of the explosive material. However, chemical profiling of explosives becomes increasingly important, as thi

  12. Retrovirus-Mediated Expression of E2A-PBX1 Blocks Lymphoid Fate but Permits Retention of Myeloid Potential in Early Hematopoietic Progenitors.

    Directory of Open Access Journals (Sweden)

    Mark W Woodcroft

    Full Text Available The oncogenic transcription factor E2A-PBX1 is expressed consequent to chromosomal translocation 1;19 and is an important oncogenic driver in cases of pre-B-cell acute lymphoblastic leukemia (ALL. Elucidating the mechanism by which E2A-PBX1 induces lymphoid leukemia would be expedited by the availability of a tractable experimental model in which enforced expression of E2A-PBX1 in hematopoietic progenitors induces pre-B-cell ALL. However, hematopoietic reconstitution of irradiated mice with bone marrow infected with E2A-PBX1-expressing retroviruses consistently gives rise to myeloid, not lymphoid, leukemia. Here, we elucidate the hematopoietic consequences of forced E2A-PBX1 expression in primary murine hematopoietic progenitors. We show that introducing E2A-PBX1 into multipotent progenitors permits the retention of myeloid potential but imposes a dense barrier to lymphoid development prior to the common lymphoid progenitor stage, thus helping to explain the eventual development of myeloid, and not lymphoid, leukemia in transplanted mice. Our findings also indicate that E2A-PBX1 enforces the aberrant, persistent expression of some genes that would normally have been down-regulated in the subsequent course of hematopoietic maturation. We show that enforced expression of one such gene, Hoxa9, a proto-oncogene associated with myeloid leukemia, partially reproduces the phenotype produced by E2A-PBX1 itself. Existing evidence suggests that the 1;19 translocation event takes place in committed B-lymphoid progenitors. However, we find that retrovirus-enforced expression of E2A-PBX1 in committed pro-B-cells results in cell cycle arrest and apoptosis. Our findings indicate that the neoplastic phenotype induced by E2A-PBX1 is determined by the developmental stage of the cell into which the oncoprotein is introduced.

  13. Preparation Technique of HMX Coated by Nano TATB Based PBX%核壳型HMX@TATB复合炸药造型粉制备技术研究

    Institute of Scientific and Technical Information of China (English)

    丁玲; 刘佳辉; 黄兵; 李洪珍

    2015-01-01

    The sensitivity of high explosive HMX can be definitely reduced by the preparation of core-shell HMX@TATB, with the high energy reserved, which showed potential in the fields of insensitive munition and safe propellants. The preparation process played a key role for the related performance and subsequent application. The stirring speed, temperature and the adding speed of polymer binder were investigated for the preparation of core-shell explosives, and the stable preparation technic of HMX coated by nano TATB based PBX was obtained on a 100 g scale.%核壳型HMX@TATB复合炸药不仅能够显著降低HMX炸药的感度,还能有效保持HMX的高能量密度水平,在未来钝感弹药和安全型高能推进剂领域展现了较好的应用前景,而核壳型HMX@TATB复合炸药基PBX的制备研究对其相关性能测试和后期应用研究起重要作用。本研究探索了核壳型HMX@TATB复合炸药为基PBX造型粉制备过程中的转速、温度和粘结剂的滴加速度等工艺参数对造粒包覆的影响,得到了稳定的百克级核壳型HMX@TATB为基PBX造型粉的造粒工艺。

  14. Understanding vented gas explosions

    Energy Technology Data Exchange (ETDEWEB)

    Lautkaski, R. [VTT Energy, Espoo (Finland). Energy Systems

    1997-12-31

    The report is an introduction to vented gas explosions for nonspecialists, particularly designers of plants for flammable gases and liquids. The phenomena leading to pressure generation in vented gas explosions in empty and congested rooms are reviewed. The four peak model of vented gas explosions is presented with simple methods to predict the values of the individual peaks. Experimental data on the external explosion of dust and gas explosions is discussed. The empirical equation relating the internal and external peak pressures in vented dust explosions is shown to be valid for gas explosion tests in 30 m{sup 3} and 550 m{sup 3} chambers. However, the difficulty of predicting the internal peak pressure in large chambers remains. Methods of explosion relief panel design and principles of vent and equipment layout to reduce explosion overpressures are reviewed. (orig.) 65 refs.

  15. Pbx-dependent regulation of lbx gene expression in developing zebrafish embryos.

    Science.gov (United States)

    Lukowski, Chris M; Drummond, Danna Lynne; Waskiewicz, Andrew J

    2011-12-01

    Ladybird (Lbx) homeodomain transcription factors function in neural and muscle development--roles conserved from Drosophila to vertebrates. Lbx expression in mice specifies neural cell types, including dorsally located interneurons and association neurons, within the neural tube. Little, however, is known about the regulation of vertebrate lbx family genes. Here we describe the expression pattern of three zebrafish ladybird genes via mRNA in situ hybridization. Zebrafish lbx genes are expressed in distinct but overlapping regions within the developing neural tube, with strong expression within the hindbrain and spinal cord. The Hox family of transcription factors, in cooperation with cofactors such as Pbx and Meis, regulate hindbrain segmentation during embryogenesis. We have identified a novel regulatory interaction in which lbx1 genes are strongly downregulated in Pbx-depleted embryos. Further, we have produced a transgenic zebrafish line expressing dTomato and EGFP under the control of an lbx1b enhancer--a useful tool to acertain neuron location, migration, and morphology. Using this transgenic strain, we have identified a minimal neural lbx1b enhancer that contains key regulatory elements for expression of this transcription factor.

  16. NEW ACHIEVEMENTS ON THE THEORY AND TECHNOLOGY OF EXPLOSIVE WELDING

    Institute of Scientific and Technical Information of China (English)

    C.G. Shi; Y.H. Wang; L.G. Cai; C.H. Zhou

    2003-01-01

    There are four new achievements of this work on the theory and technology of explosive welding.(1) It has been found and defined three kinds of bonding interfaces: big wavy, small wavy and micro wavy, and the micro wavy interface is the best. In a cladding plate,it is for the first time to find that the form of interface presents regular distribution.(2) Although the interface has the features of melt, diffusion and pressure welding in the mean time, the seam and "hole" brought by the melt weaken the bonding strength of interface greatly, and the effect of melt on interface must be eliminated in explosive welding, so explosive welding is not a melt weld. The diffusion welding is a kind of form of pressure welding, and the diffusion is not the reason of the bonding of interface but the result of interface high pressure. So the diffusion welding cannot also explain the bonding mechanism of it. The experiment and theory make clear that explosive welding is a special pressure one.(3) To get good interface of no melt, explosive charge must be selected on the low limit of welding windows. In explosive welding, the drive plate should be treated as the viscous and plastoelastic body, not incompressible fluid. The bending moment under the explosive welding loading must be greater than that under dynamic limit of drive plate. According to the condition, the lower limit of explosive welding is obtained. It is about 20% less than that obtained by tradition calculation, and suitable for engineering application.(4) It is for the first time to test and study on soil anvil characteristics and change regularity under explosive welding impact loading. Through soil anvil parameter optimization analysis, it is the best for explosive welding with sandy soil of water content 17.00% and density 1.74g/cm3.

  17. Modeling Hot-Spot Contributions in Shocked High Explosives at the Mesoscale

    Energy Technology Data Exchange (ETDEWEB)

    Harrier, Danielle [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-08-12

    When looking at performance of high explosives, the defects within the explosive become very important. Plastic bonded explosives, or PBXs, contain voids of air and bonder between the particles of explosive material that aid in the ignition of the explosive. These voids collapse in high pressure shock conditions, which leads to the formation of hot spots. Hot spots are localized high temperature and high pressure regions that cause significant changes in the way the explosive material detonates. Previously hot spots have been overlooked with modeling, but now scientists are realizing their importance and new modeling systems that can accurately model hot spots are underway.

  18. Dynamic Characterization of Mock Explosive Material Using Reverse Taylor Impact Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Ferranti, L; Gagliardi, F J; Cunningham, B J; Vandersall, K S

    2010-03-25

    The motivation for the current study is to evaluate the dynamic loading response of an inert mock explosive material used to replicate the physical and mechanical properties of LX-17-1 and PBX 9502 insensitive high explosives. The evaluation of dynamic material parameters is needed for predicting the deformation behavior including the onset of failure and intensity of fragmentation resulting from high velocity impact events. These parameters are necessary for developing and validating physically based material constitutive models that will characterize the safety and performance of energetic materials. The preliminary study uses a reverse Taylor impact configuration that was designed to measure the dynamic behavior of the explosive mock up to and including associated fragmentation. A stationary rod-shaped specimen was impacted using a compressed-gas gun by accelerating a rigid steel anvil attached to a sabot. The impact test employed high-speed imaging and velocity interferometry diagnostics for capturing the transient deformation of the sample at discrete times. Once established as a viable experimental technique with mock explosives, future studies will examine the dynamic response of insensitive high explosives and propellants.

  19. Ignition and Growth Reactive Flow Modeling of Shock Initiation of PBX 9502 at -55∘C and -196∘C

    Science.gov (United States)

    Chidester, Steven; Tarver, Craig

    2015-06-01

    Recently Gustavsen et al. and Hollowell et al. published two stage gas gun embedded particle velocity gauge experiments on PBX 9502 (95%TATB, 5% Kel-F800) cooled to -55°C and -196°C, respectively. At -196°C, PBX 9502 was shown to be much less shock sensitive than at -55°C, but it did transition to detonation. Previous Ignition and Growth model parameters for shock initiation of PBX 9502 at -55°C are modified based on the new data, and new parameters for -196°C PBX 9502 are created to accurately simulate the measured particle velocity histories and run distances to detonation versus shock pressures. This work was performed under the auspices of the U. S. Department of Energy by the Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

  20. Bond Issues.

    Science.gov (United States)

    Pollack, Rachel H.

    2000-01-01

    Notes trends toward increased borrowing by colleges and universities and offers guidelines for institutions that are considering issuing bonds to raise money for capital projects. Discussion covers advantages of using bond financing, how use of bonds impacts on traditional fund raising, other cautions and concerns, and some troubling aspects of…

  1. [Molecular biology and childhood leukemia: E2A-PBX1 and central nervous system relapse].

    Science.gov (United States)

    Núñez-Enríquez, Juan Carlos; Mejía-Aranguré, Juan Manuel

    2015-01-01

    Acute lymphoblastic leukemia (ALL) is the most common cancer in children. The inclusion of molecular biology techniques in the diagnosis and prognostic stratification of these patients has allowed major treatment achievements in developed countries. One of the best studied gene rearrangements is E2A-PBX1, which predicts isolated central nervous system relapse in patients with ALL. However, further research on the search for new molecular markers related to prognosis of patients with childhood leukemia is required. Such studies need the integration of different disciplines, including epidemiology. Epidemiological studies are needed not only to accelerate the discovery of new molecular markers and new biological signals as to the etiology and pathophysiology of cancer, but also to evaluate the clinical impact of these findings in well-defined populations. PMID:26509298

  2. Determination of the energy of suprathermal electrons during lower hybrid current drive on PBX-M

    International Nuclear Information System (INIS)

    Suprathermal electrons are diagnosed by a hard x-ray pinhole camera during lower hybrid current drive on PBX-M. The experimental hard x-ray images are compared with simulated images, which result from an integration of the relativistic bremsstrahlung along lines-of-sight through the bean-shaped plasma. Images with centrally peaked and radially hollow radiation profiles are easily distinguished. The energy distribution of the suprathermal electrons is analyzed by comparing images taken with different absorber foils. An effective photon temperature is derived from the experimental images, and a comparison with simulated photon temperatures yields the energy of the suprathermal electrons. The analysis indicates that the energy of the suprathermal electrons in the hollow discharges is in the 50 to 100 key range in the center of the discharge. There seems to exist a very small higher energy component close to the plasma edge

  3. 76 FR 64974 - Commerce in Explosives; List of Explosive Materials (2011R-18T)

    Science.gov (United States)

    2011-10-19

    ... inorganic salts. * ANFO . Aromatic nitro-compound explosive mixtures. Azide explosives. B Baranol. Baratol...). Explosive nitro compounds of aromatic hydrocarbons. Explosive organic nitrate mixtures. Explosive powders. F... explosive. Nitrated polyhydric alcohol explosives. Nitric acid and a nitro aromatic compound...

  4. 75 FR 1085 - Commerce in Explosives; List of Explosive Materials (2009R-18T)

    Science.gov (United States)

    2010-01-08

    .... *ANFO . Aromatic nitro-compound explosive mixtures. Azide explosives. B Baranol. Baratol. BEAF . Black...). Explosive nitro compounds of aromatic hydrocarbons. Explosive organic nitrate mixtures. Explosive powders. F... explosive. Nitrated polyhydric alcohol explosives. Nitric acid and a nitro aromatic compound...

  5. Associations of Polymorphisms in WNT9B and PBX1 with Mayer-Rokitansky-Kuster-Hauser Syndrome in Chinese Han.

    Directory of Open Access Journals (Sweden)

    Wenqing Ma

    Full Text Available Mayer-Rokitansky-Küster-Hauser (MRKH syndrome is a rare syndrome that is characterized by congenital aplasia of the uterus and the upper portion (2/3 of the vagina. Previous attempts to identify causal mutations of MRKH syndrome have primarily resulted in negative outcomes. We investigated whether these reported variants are associated with MRKH syndrome (types I and II in a relatively large sample size of Chinese Han patients, and whether any gene-gene epistatic interactions exist among these variants.This study included 182 unrelated Chinese women with MRKH syndrome (155 with type I and 27 with type II and 228 randomized female controls. Seventeen candidate loci in the AMH, PBX1, WNT4, WNT7A, WNT9B, HOXA10, HOXA11, LHXA1 and GALT genes were genotyped using the Sequenom MassARRAY iPLEX platform. Single-marker association, additive effects and multifactor interactions were investigated.The gene frequency distributions of MRKH type 1 and type 2 were similar. Rs34072914 in WNT9B was found to be associated with MRKH syndrome (P = 0.024, OR = 2.65, 95%CI = 1.14-6.17. The dominant models of rs34072914 and rs2275558 in WNT9B and PBX1, respectively, were significantly associated with MRKH syndrome risk in the Chinese Han patients. Additive gene-gene interaction analyses indicated a significant synergetic interaction between WNT9B and PBX1 (RERI = 1.397, AP = 0.493, SI = 4.204. Multifactor dimensionality reduction (MDR analysis revealed novel dimensional epistatic four-gene effects (AMH, PBX1, WNT7A and WNT9B in MRKH syndrome.This association study successfully identified two susceptibility SNPs (WNT9B and PBX1 associated with MRKH syndrome risk, both separately and interactively. The discovery of a four-gene epistatic effect (AMH, PBX1, WNT7A and WNT9B in MRKH syndrome provides novel information for the elucidation of the genetic mechanism underlying the etiology of MRKH syndrome.

  6. Explosive Technology Group

    Data.gov (United States)

    Federal Laboratory Consortium — The Explosive Technology Group (ETG) provides diverse technical expertise and an agile, integrated approach to solve complex challenges for all classes of energetic...

  7. E2a/Pbx1 Induces the Rapid Proliferation of Stem Cell Factor-Dependent Murine Pro-T Cells That Cause Acute T-Lymphoid or Myeloid Leukemias in Mice

    OpenAIRE

    Sykes, David B.; Kamps, Mark P.

    2004-01-01

    Oncoprotein E2a/Pbx1 is produced by the t(1;19) chromosomal translocation of human pre-B acute lymphoblastic leukemia. E2a/Pbx1 blocks differentiation of primary myeloid progenitors but, paradoxically, induces apoptosis in established pre-B-cell lines, and no transforming function of E2a/Pbx1 has been reported in cultured lymphoid progenitors. Here, we demonstrate that E2a/Pbx1 induces immortal proliferation of stem cell factor (SCF)-dependent pro-T thymocytes by a mechanism dependent upon bo...

  8. Reaction of Explosive Subassembly under Simulated Drop Test%炸药件在模拟跌落试验中的响应

    Institute of Scientific and Technical Information of China (English)

    高大元; 申春迎; 黄谦; 文尚刚; 黄毅民; 李敬明

    2012-01-01

    To understand the effect of accelerated aging on impact safety of explosive subassembly, the accelerated aging test of temperature 65°C , time 180 d and 365 d was done. The simulating drop test method of explosive subassembly with φ100 mm were established. For the novel and accelerated aging PBX-6 explosive subassembly,the simulating drop test with inside and outside shell were done. The reaction grades were estimated according to the reaction over pressure measured by blast pressure gauges, the ignition process of explosive subassembly at different drop velocity shooted by high-speed motion pictures and combined to photographs of experimental scrap. The results showed that for the explosive subassembly of novel or same accelerated aging time, the reaction over pressure and the deflagrate reaction grade were much bigger with drop height increasement. For the explosive subassembly of novel and accelerated aging, the reaction over pressure and the deflagrate reaction grade of accelerated aging explosive subassembly were bigger, the impact safety was decreased at same drop height.%为了解加速老化对炸药件撞击安全性的影响,开展了PBX-6炸药件在温度65℃、时间180d和365d的加速老化试验,建立了Φ100 mm炸药件模拟跌落试验方法.对加速老化前后的PBX-6炸药件进行了带内外壳约束的模拟跌落试验,根据压力传感器测量炸药反应产生的冲击波超压,用高速相机拍摄炸药件不同速度的跌落撞靶过程,结合收集的实验残余物形貌来评定反应等级.结果表明,对于未老化或加速老化时间相同的试样,跌落高度越高,爆炸冲击波超压和爆燃反应程度越大.对于未老化和加速老化试样,跌落高度相同时,老化试样的爆炸冲击波超压和爆燃反应程度较大,撞击安全性降低.

  9. Steam explosion studies review

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Moon Kyu; Kim, Hee Dong

    1999-03-01

    When a cold liquid is brought into contact with a molten material with a temperature significantly higher than the liquid boiling point, an explosive interaction due to sudden fragmentation of the melt and rapid evaporation of the liquid may take place. This phenomenon is referred to as a steam explosion or vapor explosion. Depending upon the amount of the melt and the liquid involved, the mechanical energy released during a vapor explosion can be large enough to cause serious destruction. In hypothetical severe accidents which involve fuel melt down, subsequent interactions between the molten fuel and coolant may cause steam explosion. This process has been studied by many investigators in an effort to assess the likelihood of containment failure which leads to large scale release of radioactive materials to the environment. In an effort to understand the phenomenology of steam explosion, extensive studies has been performed so far. The report presents both experimental and analytical studies on steam explosion. As for the experimental studies, both small scale tests which involve usually less than 20 g of high temperature melt and medium/large scale tests which more than 1 kg of melt is used are reviewed. For the modelling part of steam explosions, mechanistic modelling as well as thermodynamic modelling is reviewed. (author)

  10. Steam explosion studies review

    International Nuclear Information System (INIS)

    When a cold liquid is brought into contact with a molten material with a temperature significantly higher than the liquid boiling point, an explosive interaction due to sudden fragmentation of the melt and rapid evaporation of the liquid may take place. This phenomenon is referred to as a steam explosion or vapor explosion. Depending upon the amount of the melt and the liquid involved, the mechanical energy released during a vapor explosion can be large enough to cause serious destruction. In hypothetical severe accidents which involve fuel melt down, subsequent interactions between the molten fuel and coolant may cause steam explosion. This process has been studied by many investigators in an effort to assess the likelihood of containment failure which leads to large scale release of radioactive materials to the environment. In an effort to understand the phenomenology of steam explosion, extensive studies has been performed so far. The report presents both experimental and analytical studies on steam explosion. As for the experimental studies, both small scale tests which involve usually less than 20 g of high temperature melt and medium/large scale tests which more than 1 kg of melt is used are reviewed. For the modelling part of steam explosions, mechanistic modelling as well as thermodynamic modelling is reviewed. (author)

  11. Explosions and static electricity

    DEFF Research Database (Denmark)

    Jonassen, Niels M

    1995-01-01

    The paper deals with the problem of electrostatic discharges as causes of ignition of vapor/gas and dust/gas mixtures. A series of examples of static-caused explosions will be discussed. The concepts of explosion limits, the incendiveness of various discharge types and safe voltages are explained...

  12. Parental Bonding

    Directory of Open Access Journals (Sweden)

    T. Paul de Cock

    2014-08-01

    Full Text Available Estimating the early parent–child bonding relationship can be valuable in research and practice. Retrospective dimensional measures of parental bonding provide a means for assessing the experience of the early parent–child relationship. However, combinations of dimensional scores may provide information that is not readily captured with a dimensional approach. This study was designed to assess the presence of homogeneous groups in the population with similar profiles on parental bonding dimensions. Using a short version of the Parental Bonding Instrument (PBI, three parental bonding dimensions (care, authoritarianism, and overprotection were used to assess the presence of unobserved groups in the population using latent profile analysis. The class solutions were regressed on 23 covariates (demographics, parental psychopathology, loss events, and childhood contextual factors to assess the validity of the class solution. The results indicated four distinct profiles of parental bonding for fathers as well as mothers. Parental bonding profiles were significantly associated with a broad range of covariates. This person-centered approach to parental bonding has broad utility in future research which takes into account the effect of parent–child bonding, especially with regard to “affectionless control” style parenting.

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

    International Nuclear Information System (INIS)

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

  14. Liquid explosives detection

    Science.gov (United States)

    Burnett, Lowell J.

    1994-03-01

    A Liquid Explosives Screening System capable of scanning unopened bottles for liquid explosives has been developed. The system can be operated to detect specific explosives directly, or to verify the labeled or bar-coded contents of the container. In this system nuclear magnetic resonance (NMR) is used to interrogate the liquid. NMR produces an extremely rich data set and many parameters of the NMR response can be determined simultaneously. As a result, multiple NMR signatures may be defined for any given set of liquids, and the signature complexity then selected according to the level of threat.

  15. Explosive Components Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The 98,000 square foot Explosive Components Facility (ECF) is a state-of-the-art facility that provides a full-range of chemical, material, and performance analysis...

  16. Intermittent Explosive Disorder

    Directory of Open Access Journals (Sweden)

    Lut Tamam

    2011-09-01

    Full Text Available Intermittent explosive disorder is an impulse control disorder characterized by the occurrence of discrete episodes of failure to resist aggressive impulses that result in violent assault or destruction of property. Though the prevalence intermittent explosive disorder has been reported to be relatively rare in frontier studies on the field, it is now common opinion that intermittent explosive disorder is far more common than previously thought especially in clinical psychiatry settings. Etiological studies displayed the role of both psychosocial factors like childhood traumas and biological factors like dysfunctional neurotransmitter systems and genetics. In differential diagnosis of the disorder, disorders involving agression as a symptom such as alcohol and drug intoxication, antisocial and borderline personality disorders, personality changes due to general medical conditions and behavioral disorder should be considered. A combination of pharmacological and psychotherapeutic approaches are suggested in the treatment of the disorder. This article briefly reviews the historical background, diagnostic criteria, epidemiology, etiology and treatment of intermittent explosive disorder.

  17. Shock waves & explosions

    CERN Document Server

    Sachdev, PL

    2004-01-01

    Understanding the causes and effects of explosions is important to experts in a broad range of disciplines, including the military, industrial and environmental research, aeronautic engineering, and applied mathematics. Offering an introductory review of historic research, Shock Waves and Explosions brings analytic and computational methods to a wide audience in a clear and thorough way. Beginning with an overview of the research on combustion and gas dynamics in the 1970s and 1980s, the author brings you up to date by covering modeling techniques and asymptotic and perturbative methods and ending with a chapter on computational methods.Most of the book deals with the mathematical analysis of explosions, but computational results are also included wherever they are available. Historical perspectives are provided on the advent of nonlinear science, as well as on the mathematical study of the blast wave phenomenon, both when visualized as a point explosion and when simulated as the expansion of a high-pressure ...

  18. Modeling nuclear explosion

    Science.gov (United States)

    Redd, Jeremy; Panin, Alexander

    2012-10-01

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

  19. Parametric Explosion Spectral Model

    Energy Technology Data Exchange (ETDEWEB)

    Ford, S R; Walter, W R

    2012-01-19

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

  20. Aging of civil explosives (Poster)

    NARCIS (Netherlands)

    Krabbendam-La Haye, E.L.M.; Klerk, W.P.C. de; Hoen, C. 't; Krämer, R.E.

    2014-01-01

    For the Dutch MoD and police, TNO composed sets with different kinds of civil explosives to train their detection dogs. The manufacturer of these explosives guarantees several years of stability of these explosives. These sets of explosives are used under different conditions, like temperature and h

  1. Non-isothermal crystallization kinetics of ternary Se90Te10-xPbx glasses

    Science.gov (United States)

    Atyia, H. E.; Farid, A. S.

    2016-02-01

    Ternary Se90Te10-xPbx with (x=2 and 6 at%) glass compositions have been prepared using a melt quenching technique and performed the non-isothermal kinetics by differential thermal analysis (DTA) at various heating rates. The glassy state of the studied samples has been characterized using x-ray diffraction analysis. The glass transition temperature Tg, the onset temperature of crystallization Tc and the peak temperature of crystallization Tp are found to be composition and heating rate dependent. From heating rate dependence of Tg and Tp, the glass transition activation energies Eg and the crystallization activation energies Ec have been determined according to different methods. The transformation mechanisms have been examined by the values of Avrami exponent n and dimensionality of growth m. Thermal stability and glass formation ability have been monitored through the calculation of the thermal stability S, temperature difference ΔT, Hurby parameter Hr, frequency factor Ko, crystallization rate factor K and fragility index F. The compositional dependence of the above-mentioned parameters indicate that, the stability of the studied glass samples decreases with increasing Pb at% content.

  2. Some effects of MHD activity on impurity transport in the PBX tokamak

    International Nuclear Information System (INIS)

    The effects of MHD activity on intrinsic impurity transport are studied in ohmic discharges of the Princeton Beta Experiment (PBX) by measuring of the Z/sub eff/ profile from visible bremsstrahlung radiation and the spectral line intensities from ultraviolet spectroscopy. A diffusive/convective transport model, including an internal disruption model, is used to simulate the data. The Z/sub eff/ profile with no MHD activity is fitted with a strong inward convection, characterized by a peaking parameter c/sub v/ (= -a2v/2rD) = 11 (3.5, +4.5). At the onset of MHD activity (a large m = 1 n = 1 oscillation followed by sawteeth), this strongly peaked profile is flattened and subsequently reaches a new quasi-equilibrium shape. This profile is characterized by reduced convection [c/sub v/ = 3.6 (-1.1, +1.6), D = 1.4 (-0.7, +5.6) x 104 cm2/s], in addition to the particle redistribution which accompanies the sawtooth internal disruptions. 10 figs

  3. Some effects of MHD activity on impurity transport in the PBX tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Ida, K.; Fonck, R.J.; Hulse, R.A.; LeBlanc, B.

    1985-10-01

    The effects of MHD activity on intrinsic impurity transport are studied in ohmic discharges of the Princeton Beta Experiment (PBX) by measuring of the Z/sub eff/ profile from visible bremsstrahlung radiation and the spectral line intensities from ultraviolet spectroscopy. A diffusive/convective transport model, including an internal disruption model, is used to simulate the data. The Z/sub eff/ profile with no MHD activity is fitted with a strong inward convection, characterized by a peaking parameter c/sub v/ (= -a/sup 2/v/2rD) = 11 (3.5, +4.5). At the onset of MHD activity (a large m = 1 n = 1 oscillation followed by sawteeth), this strongly peaked profile is flattened and subsequently reaches a new quasi-equilibrium shape. This profile is characterized by reduced convection (c/sub v/ = 3.6 (-1.1, +1.6), D = 1.4 (-0.7, +5.6) x 10/sup 4/ cm/sup 2//s), in addition to the particle redistribution which accompanies the sawtooth internal disruptions. 10 figs.

  4. A folded waveguide ICRF antenna for PBX-M and TFTR

    International Nuclear Information System (INIS)

    The folded waveguide (FWG) antenna is an advanced ICRF launcher under development at ORNL that offers many significant advantages over current-strap type antennas. These features are particularly beneficial for reactor-relevant applications such as ITER and TPX. Previous tests of a development folded waveguide with a low density plasma load have shown a factor of 5 increase in power capability over loop antennas into similar plasma conditions. The performance and reliability of a FWG with an actual tokamak plasma load must now be verified for further acceptance of this concept. A 58 MHz, 4 MW folded waveguide is being designed and built for the PBX-M and TFTR tokamaks at Princeton Plasma Physics Laboratory. This design has a square cross-section that can be installed as either a fast wave (FW) or ion-Bernstein wave (IBW) launcher by 90 degree rotation. Two new features of the design are: a shorter quarter-wavelength resonator configuration and a rear-feed input power coupling loop. Loading calculations with a standard shorting plate indicate that a launched power level of 4 MW is possible on either machine. Mechanical and disruption force analysis indicates that bolted construction will withstand the disruption loads. An experimental program is planned to characterize the plasma loading, heating effectiveness, power capability, impurity generation and other factors for both FW and IBW cases. High power tests of the new configuration are being performed with a development FWG unit on RFTF at ORNL

  5. Modelling of gas explosions

    OpenAIRE

    Vågsæther, Knut

    2010-01-01

    The content of this thesis is a study of gas explosions in complex geometries and presentation and validation of a method for simulating flame acceleration and deflagration to detonation transition. The thesis includes a description of the mechanisms of flame acceleration and DDT that need to be modeled when simulating all stages of gas explosions. These mechanisms are flame acceleration due to instabilities that occur in fluid flow and reactive systems, shock propagation, deflagration to det...

  6. Explosive Welding with Nitroguanidine.

    Science.gov (United States)

    Sadwin, L D

    1964-03-13

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

  7. Chemical Explosion Database

    Science.gov (United States)

    Johansson, Peder; Brachet, Nicolas

    2010-05-01

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

  8. Bond Boom

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The Ministry of Finance recently kick-started a pilot program allowing local governments of Shanghai and Shenzhen, and Zhejiang and Guangdong provinces to issue bonds for the first time. How will the new policy affect fiscal capacities of local governments and the broader economy? What else should the country do to build a healthy bond market? Economists and experts discussed these issues in an interview with the ShanghaiSecuritiesJournal. Edited excerpts follow:

  9. Bond Boom

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The Ministry of Finance recently kick-started a pilot program allowing local governments of Shanghai and Shenzhen,and Zhejiang and Guangdong provinces to issue bonds for the first time.How will the new policy affect fiscal capacities of local governments and the broader economy? What else should the country do to build a healthy bond market? Economists and experts discussed these issues in an interview with the Shanghai Securities Journal.Edited excerpts follow.

  10. Underground explosion barriers - a review

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, B.; O`Beirne, T. [ACIRL Ltd., Booval, Qld. (Australia)

    1997-12-31

    The paper focuses on explosibility conditions in underground coal mines, the behaviour of explosions from initiating gas ignition to violent dust explosions and the effectiveness and limits of operation of current designs of passive explosion barriers in suppressing the flame front. The paper also discusses performance evaluations made in full scale explosion galleries and the use of alternatives to passive barriers, including the installation of active barriers under some circumstances.

  11. Synthesis of Diphenyl Carbonate over the Magnetic Catalysts Pd/La1-xPbxMnO3(x =0.2-0.7)

    Institute of Scientific and Technical Information of China (English)

    LU Wei; DU Zhiping; YUAN Hua; TIAN Qifeng; WU Yuanxin

    2013-01-01

    The magnetic perovskite-supported palladium catalysts Pd/La1-xPbxMnO3 (x =0.2-0.7) were prepared and used for the oxidative carbonylation of phenol to diphenyl carbonate.The synthesized catalysts were characterized by the X-ray diffraction (XRD),surface area measurement BET,vibration sample magnetometer (VSM) and tem-perature-programmed reduction (TPR).The experimental results demonstrated that the magnetic Pd/La1-xPbxMnO3 (x =0.4-0.5) obtain relative better catalytic activity.It can be explained by higher concentration of oxygen vacancies,larger amount and better mobility of lattice oxygen of their support.Furthermore,these samples possess sufficient saturated magnetization.Thus,Pd/La1-xPbxMnO3 (x =0.4-0.5) may be suitable for operation in the magnetically stabilized bed reactor.

  12. E2A-Pbx1, the t(1;19) translocation protein of human pre-B-cell acute lymphocytic leukemia, causes acute myeloid leukemia in mice

    OpenAIRE

    Kamps, M P; Baltimore, D

    1993-01-01

    One-quarter of pediatric pre-B-cell leukemias contain the t(1;19) chromosomal translocation, which fuses 5' exons encoding the transactivation domain of the E2A transcription factor gene to 3' exons ecoding the putative DNA-binding region of the unusual homeobox gene, PBX1. To test the leukemic potential of this fused gene, a cDNA encoding its major protein product, p85E2A-Pbx1, was incorporated into a retrovirus construct and introduced into normal mouse marrow progenitors by infection. The ...

  13. Assay of nitroplasticizer for PBX 9501. Period covered: January--March 1976. Normal process development endeavor No. 105

    Energy Technology Data Exchange (ETDEWEB)

    MacDougall, C.S.

    1976-01-01

    A series of standard procedures for component and contaminant analysis of the nitroplasticizer in PBX 9501 was checked for accuracy and precision. Acid number was determined by a titration with methanolic KOH. Water was assayed by a Karl Fisher titration. The refractive index was measured at 25/sup 0/C by a refractometer, and density was determined by a pycnometer. The BDNPA/BDNPF was assayed by a liquid chromatographic technique. A gas chromatographic method was developed for determination of ethanol. The antioxidant was measured by a spectrophotometric method.

  14. Ancient Pbx-Hox signatures define hundreds of vertebrate developmental enhancers

    Directory of Open Access Journals (Sweden)

    Parker Hugo J

    2011-12-01

    Full Text Available Abstract Background Gene regulation through cis-regulatory elements plays a crucial role in development and disease. A major aim of the post-genomic era is to be able to read the function of cis-regulatory elements through scrutiny of their DNA sequence. Whilst comparative genomics approaches have identified thousands of putative regulatory elements, our knowledge of their mechanism of action is poor and very little progress has been made in systematically de-coding them. Results Here, we identify ancient functional signatures within vertebrate conserved non-coding elements (CNEs through a combination of phylogenetic footprinting and functional assay, using genomic sequence from the sea lamprey as a reference. We uncover a striking enrichment within vertebrate CNEs for conserved binding-site motifs of the Pbx-Hox hetero-dimer. We further show that these predict reporter gene expression in a segment specific manner in the hindbrain and pharyngeal arches during zebrafish development. Conclusions These findings evoke an evolutionary scenario in which many CNEs evolved early in the vertebrate lineage to co-ordinate Hox-dependent gene-regulatory interactions that pattern the vertebrate head. In a broader context, our evolutionary analyses reveal that CNEs are composed of tightly linked transcription-factor binding-sites (TFBSs, which can be systematically identified through phylogenetic footprinting approaches. By placing a large number of ancient vertebrate CNEs into a developmental context, our findings promise to have a significant impact on efforts toward de-coding gene-regulatory elements that underlie vertebrate development, and will facilitate building general models of regulatory element evolution.

  15. Explosive Welding with Nitroguanidine.

    Science.gov (United States)

    Sadwin, L D

    1964-03-13

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

  16. 77 FR 58410 - Commerce in Explosives; List of Explosive Materials (2012R-10T)

    Science.gov (United States)

    2012-09-20

    ... salt lattice with isomorphously substituted inorganic salts. * ANFO . Aromatic nitro-compound explosive.... Explosive mixtures containing tetranitromethane (nitroform). Explosive nitro compounds of aromatic... polyhydric alcohol explosives. Nitric acid and a nitro aromatic compound explosive. Nitric acid...

  17. 75 FR 70291 - Commerce in Explosives; List of Explosive Materials (2010R-27T)

    Science.gov (United States)

    2010-11-17

    ... salt lattice with isomorphously substituted inorganic salts. * ANFO . Aromatic nitro-compound explosive.... Explosive mixtures containing tetranitromethane (nitroform). Explosive nitro compounds of aromatic... polyhydric alcohol explosives. Nitric acid and a nitro aromatic compound explosive. Nitric acid...

  18. Portable raman explosives detection

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-01-01

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

  19. Topological crystalline insulator PbxSn1-xTe thin films on SrTiO3 (001 with tunable Fermi levels

    Directory of Open Access Journals (Sweden)

    Hua Guo

    2014-05-01

    Full Text Available In this letter, we report a systematic study of topological crystalline insulator PbxSn1-xTe (0 < x < 1 thin films grown by molecular beam epitaxy on SrTiO3(001. Two domains of PbxSn1-xTe thin films with intersecting angle of α ≈ 45° were confirmed by reflection high energy diffraction, scanning tunneling microscopy, and angle-resolved photoemission spectroscopy (ARPES. ARPES study of PbxSn1-xTe thin films demonstrated that the Fermi level of PbTe could be tuned by altering the temperature of substrate whereas SnTe cannot. An M-shaped valance band structure was observed only in SnTe but PbTe is in a topological trivial state with a large gap. In addition, co-evaporation of SnTe and PbTe results in an equivalent variation of Pb concentration as well as the Fermi level of PbxSn1-xTe thin films.

  20. Diffusion bonding

    Science.gov (United States)

    Anderson, Robert C.

    1976-06-22

    1. A method for joining beryllium to beryllium by diffusion bonding, comprising the steps of coating at least one surface portion of at least two beryllium pieces with nickel, positioning a coated surface portion in a contiguous relationship with an other surface portion, subjecting the contiguously disposed surface portions to an environment having an atmosphere at a pressure lower than ambient pressure, applying a force upon the beryllium pieces for causing the contiguous surface portions to abut against each other, heating the contiguous surface portions to a maximum temperature less than the melting temperature of the beryllium, substantially uniformly decreasing the applied force while increasing the temperature after attaining a temperature substantially above room temperature, and maintaining a portion of the applied force at a temperature corresponding to about maximum temperature for a duration sufficient to effect the diffusion bond between the contiguous surface portions.

  1. Mechanical Failure of a Plastic Bonded Explosive vs Confining Pressure

    Science.gov (United States)

    Wiegand, Donald; Elllis, Kevin; Leppard, Claire

    2011-06-01

    EDC37 fails by crack growth between 0.1 and about 7 MPa and by yield and plastic flow between about 7 and at least 138 MPa. In the low pressure range the compressive strength increases with pressure due to a threshold stress which also increases with pressure. The threshold stress is due to friction between crack surfaces and must be overcome for crack growth. In the higher pressure range the yield strength also increases with pressure but at a much lower rate. In the low pressure range the threshold stress for crack growth is less than the yield strength so primarily crack growth is observed while in the higher pressure range the yield strength is less the the threshold stress for crack growth so that only yield is observed. Thus at moderately low confining pressures greater than 7 MPa crack growth does not take place and so processes depending on crack motion such as frictional heating will not take place. Supported by AWE Aldermaston

  2. Explosive Nucleosynthesis in Hypernovae

    CERN Document Server

    Nakamura, T; Iwamoto, K; Nomoto, K; Hashimoto, M; Hix, W R; Thielemann, F K; Nakamura, Takayoshi; Umeda, Hideyuki; Iwamoto, Koichi; Nomoto, Ken'ichi; Hashimoto, Masa-aki; Thielemann, Friedrich-Karl

    2000-01-01

    We examine the characteristics of nucleosynthesis in 'hypernovae', i.e., supernovae with very large explosion energies ($ \\gsim 10^{52} $ ergs). We carry out detailed nucleosynthesis calculations for these energetic explosions and compare the yields with those of ordinary core-collapse supernovae. We find that both complete and incomplete Si-burning takes place over more extended, lower density regions, so that the alpha-rich freezeout is enhanced in comparison with ordinary supernova nucleosynthesis. In addition, oxygen and carbon burning takes place in more extended, lower density regions than in ordinary supernovae. Therefore, the fuel elements O, C, Al are less abundant while a larger amount of burning products such as Si, S, and Ar are synthesized by oxygen burning. Implications for Galactic chemical evolution and the abundances in metal-poor stars are also discussed.

  3. Measurement of the flow properties within a copper tube containing a deflagrating explosive

    Energy Technology Data Exchange (ETDEWEB)

    Hill, Larry G [Los Alamos National Laboratory; Morris, John S [Los Alamos National Laboratory; Jackson, Scott I [Los Alamos National Laboratory

    2009-01-01

    We report on the propagation of deflagration waves in the high explosive (HE) PBX 9501 (95 wt % HMX, 5 wt% binder). Our test configuration, which we call the def1agration cylinder test (DFCT), is fashioned after the detonation cylinder test (DTCT) that is used to calibrate the JWL detonation product equation of state (EOS). In the DFCT, the HE is heated to a uniform slightly subcritical temperature, and is ignited at one end by a hot wire. For some configurations and initial conditions, we observe a quasi-steady wave that flares the tube into a funnel shape, stretching it to the point of rupture. This behavior is qualitatively like the DTCT, such that, by invoking certain additional approximations that we discuss, its behavior can be analyzed by the same methods. We employ an analysis proposed by G.I. Taylor to infer the pressure-volume curve for the burning, expanding flow. By comparing this result to the EOS of HMX product gas alone. we infer that only {approx}20 wt% of the HMX has burned at tube rupture. This result confirms pre-existing observations about the role of convective burning in HMX cookoff explosions.

  4. Spall strength and ejecta production of gold under explosively driven shock wave compression

    Energy Technology Data Exchange (ETDEWEB)

    La Lone, B. M. [National Security Technologies, LLC. (NSTec), Mercury, NV (United States); Stevens, G. D. [National Security Technologies, LLC. (NSTec), Mercury, NV (United States); Turley, W. D. [National Security Technologies, LLC. (NSTec), Mercury, NV (United States); Veeser, L. R. [National Security Technologies, LLC. (NSTec), Mercury, NV (United States); Holtkamp, D. B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2013-12-16

    Explosively driven shock wave experiments were conducted to characterize the spall strength and ejecta production of high-purity cast gold samples. The samples were from 0.75 to 1.84 mm thick and 30 mm in diameter. Peak stresses up to 44 GPa in gold were generated using PBX-9501 high explosive. Sample free surface and ejecta velocities were recorded using photonic Doppler velocimetry techniques. Lithium niobate pins were used to quantify the time dependence of the ejecta density and the total ejected mass. An optical framing camera for time-resolved imaging and a single-image x-ray radiograph were used for additional characterization. Free surface velocities exhibited a range of spall strengths from 1.7 to 2.4 GPa (mean: 2.0 ±0.3 GPa). The pullback signals were faint, minimal ringing was observed in the velocity records, and the spall layer continued to decelerate after first pull back. These results suggest finite tensile strength was present for some time after the initial void formation. Ejecta were observed for every sample with a roughened free surface, and the ejecta density increased with increased surface roughness, which was different in every experiment. The total ejected mass is consistent with the missing mass model.

  5. Explosions in November

    OpenAIRE

    Steinitz, Richard

    2011-01-01

    Explosions in November tells the story of one of Europe’s leading cultural institutions, Huddersfield Contemporary Music Festival (hcmf), through the eyes of its founder and former artistic director, Professor Richard Steinitz. From its modest beginnings in 1978, when winter fog nearly sabotaged the inaugural programme, to today’s internationally renowned event, hcmf has been a pioneering champion of the best in contemporary music. Commissioning new work, reappraising existing legacies an...

  6. Explosives signatures and analysis

    Science.gov (United States)

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

    2008-04-01

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

  7. Characteristic Research on Evaporated Explosive Film

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The evaporation source of evaporated explosive was designed and improved based on the inherent specialties of explosive. The compatibility of explosives and addition agent with evaporation vessels was analyzed. The influence of substrate temperature on explosive was analyzed, the control method of substrate temperature was suggested. The influences of evaporation rate on formation of explosive film and mixed explosive film were confirmed. Optimum evaporation rate for evaporation explosive and the better method for evaporating mixed explosive were presented. The necessary characteristics of the evaporated explosive film were obtained by the research of the differences between the evaporated explosive and other materials.

  8. Visible-active photocatalytic behaviors observed in nanostructured lead chalcogenides PbX (X = S, Se, Te)

    International Nuclear Information System (INIS)

    Nanostructured lead chalcogenides (PbX, X = Te, Se, S) were prepared via a simple hydrothermal method. The powder samples were characterized by XRD, SEM, SAED and DRS. Phase composition and microstructure analysis indicate that these samples are pure lead chalcogenides phases and have similar morphologies. These lead chalcogenides display efficient absorption in the UV-visible light range. The photocatalytic properties of lead chalcogenides nanoparticles were evaluated by the photodegradation of Congo red under UV-visible light irradiation in air atmosphere. The Congo red solution can be efficiently degraded under visible light in the presence of lead chalcogenides nanoparticles. The photocatalytic activities of lead chalcogenides generally increase with increasing their band gaps and shows no appreciable loss after repeated cycles. Our results may be useful for developing new photocatalyst systems responsive to visible light among narrow band gap semiconductors

  9. Depth resolution at profile Auger analysis of the ZnS-PbxSn1-xTe structures

    International Nuclear Information System (INIS)

    The reasons have been studied of anomalously large broadening of profiles at the interface at profile Auger-analysis of the structures ZnS-PbxSn1-xTe, grown by a moleclar-beam epitaxy method. It is shown that this broadening is not related with the existance of the extended region of a valiable composition. Other possible mechanisms of profile persistance have been studied experimentally. In place of the analysis an effectively greater rate of ion etching is observed. It is found that the Auger-profile shape near the interface is determined by the surface relief formation at ion etching. It is shown that the reason of the formation of a developed relief of the surface in the place periodically irradiated by the electron beam during obtaining the Auger-spectra has an electrostatic character. Two possible mechanisms of such relies formation are discussed

  10. Visible-active photocatalytic behaviors observed in nanostructured lead chalcogenides PbX (X = S, Se, Te)

    Energy Technology Data Exchange (ETDEWEB)

    Qiao, Li-Na; Wang, H.C.; Shen, Y.; Lin, Yuan-Hua, E-mail: linyh@mail.tsinghua.edu.cn; Nan, Ce-Wen [State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2016-01-15

    Nanostructured lead chalcogenides (PbX, X = Te, Se, S) were prepared via a simple hydrothermal method. The powder samples were characterized by XRD, SEM, SAED and DRS. Phase composition and microstructure analysis indicate that these samples are pure lead chalcogenides phases and have similar morphologies. These lead chalcogenides display efficient absorption in the UV-visible light range. The photocatalytic properties of lead chalcogenides nanoparticles were evaluated by the photodegradation of Congo red under UV-visible light irradiation in air atmosphere. The Congo red solution can be efficiently degraded under visible light in the presence of lead chalcogenides nanoparticles. The photocatalytic activities of lead chalcogenides generally increase with increasing their band gaps and shows no appreciable loss after repeated cycles. Our results may be useful for developing new photocatalyst systems responsive to visible light among narrow band gap semiconductors.

  11. Gas explosions in process pipes

    OpenAIRE

    Kristoffersen, Kjetil

    2004-01-01

    In this thesis, gas explosions inside pipes are considered. Laboratory experiments and numerical simulations are the basis of the thesis. The target of the work was to study gas explosions in pipes and to develop numer- ical models that could predict accidental gas explosions inside pipes. Experiments were performed in circular steel and plexiglass pipes. The steel pipes have an inner diameter of 22.3 mm and lengths of 1, 2, 5 and 11 m. The plexiglass pipe has an inner diame...

  12. PROBABILISTIC MODELING OF EXPLOSIVE LOADING

    OpenAIRE

    Mkrtychev Oleg Vartanovich; Dorozhinskiy Vladimir Bogdanovich

    2012-01-01

    According to existing design standards, explosive loading represents a special type of loading. Explosive loading is, in most cases, local in nature, although it can exceed the loads for which buildings are designed by a dozen of times. The analysis of terrorist attacks with explosives employed demonstrates that charges have a great power and, consequently, a substantial shock wave pressure. Blast effects are predictable with a certain probability. Therefore, we cannot discuss ...

  13. Prediction of crystal densities of organic explosives by group additivity

    Energy Technology Data Exchange (ETDEWEB)

    Stine, J R

    1981-08-01

    The molar volume of crystalline organic compound is assumed to be a linear combination of its constituent volumes. Compounds consisting only of the elements hydrogen, carbon, nitrogen, oxygen, and fluorine are considered. The constituent volumes are taken to be the volumes of atoms in particular bonding environments and are evaluated from a large set of crystallographic data. The predicted density has an expected error of about 3%. These results are applied to a large number of explosives compounds.

  14. Controlled by Distant Explosions

    Science.gov (United States)

    2007-03-01

    VLT Automatically Takes Detailed Spectra of Gamma-Ray Burst Afterglows Only Minutes After Discovery A time-series of high-resolution spectra in the optical and ultraviolet has twice been obtained just a few minutes after the detection of a gamma-ray bust explosion in a distant galaxy. The international team of astronomers responsible for these observations derived new conclusive evidence about the nature of the surroundings of these powerful explosions linked to the death of massive stars. At 11:08 pm on 17 April 2006, an alarm rang in the Control Room of ESO's Very Large Telescope on Paranal, Chile. Fortunately, it did not announce any catastrophe on the mountain, nor with one of the world's largest telescopes. Instead, it signalled the doom of a massive star, 9.3 billion light-years away, whose final scream of agony - a powerful burst of gamma rays - had been recorded by the Swift satellite only two minutes earlier. The alarm was triggered by the activation of the VLT Rapid Response Mode, a novel system that allows for robotic observations without any human intervention, except for the alignment of the spectrograph slit. ESO PR Photo 17a/07 ESO PR Photo 17a/07 Triggered by an Explosion Starting less than 10 minutes after the Swift detection, a series of spectra of increasing integration times (3, 5, 10, 20, 40 and 80 minutes) were taken with the Ultraviolet and Visual Echelle Spectrograph (UVES), mounted on Kueyen, the second Unit Telescope of the VLT. "With the Rapid Response Mode, the VLT is directly controlled by a distant explosion," said ESO astronomer Paul Vreeswijk, who requested the observations and is lead-author of the paper reporting the results. "All I really had to do, once I was informed of the gamma-ray burst detection, was to phone the staff astronomers at the Paranal Observatory, Stefano Bagnulo and Stan Stefl, to check that everything was fine." The first spectrum of this time series was the quickest ever taken of a gamma-ray burst afterglow

  15. Laser machining of explosives

    Science.gov (United States)

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

    2000-01-01

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

  16. Tenderizing Meat with Explosives

    Science.gov (United States)

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

    2001-06-01

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

  17. Energetic lanthanide complexes: coordination chemistry and explosives applications

    International Nuclear Information System (INIS)

    Metals are generally added to organic molecular explosives in a heterogeneous composite to improve overall heat and energy release. In order to avoid creating a mixture that can vary in homogeneity, energetic organic molecules can be directly bonded to high molecular weight metals, forming a single metal complex with Angstrom-scale separation between the metal and the explosive. To probe the relationship between the structural properties of metal complexes and explosive performance, a new series of energetic lanthanide complexes has been prepared using energetic ligands such as NTO (5-nitro-2,4-dihydro-1,2,4-triazole-3-one). These are the first examples of lanthanide NTO complexes where no water is coordinated to the metal, demonstrating novel control of the coordination environment. The complexes have been characterized by X-ray crystallography, NMR and IR spectroscopies, photoluminescence, and sensitivity testing. The structural and energetic properties are discussed in the context of enhanced blast effects and detection. Cheetah calculations have been performed to fine-tune physical properties, creating a systematic method for producing explosives with 'tailor made' characteristics. These new complexes will be benchmarks for further study in the field of metalized high explosives.

  18. Characteristics of a New Plastic Explosive Named EPX-1

    Directory of Open Access Journals (Sweden)

    Ahmed Elbeih

    2015-01-01

    Full Text Available EPX-1 is a new plastic explosive (in the research stage which has been prepared for military and civilian applications. EPX-1 explosive contains pentaerythritol tetranitrate (PETN with different particle size as explosive filler bonded by nonenergetic thermoplastic binder plasticized by dibutyl phthalate (DBP. In this paper, the production method of EPX-1 was described. The crystal morphology was studied by scanning electron microscope (SEM. Heat of combustion was determined experimentally. The compatibility of PETN with the polymeric matrix was studied by vacuum stability test. Sensitivities to impact and friction were measured. The detonation velocity was measured experimentally and the detonation characteristics were calculated by EXPLO5 thermodynamic code. For comparison, Semtex 1A, Semtex 10, Formex P1, and Sprängdeg m/46 were studied. It was concluded that PEX-1 has compatible ingredients, it has the highest detonation velocity of all the studied plastic explosives, and its sensitivity is in the same level of the studied plastic explosives except Semtex 1A.

  19. 中小型IP PBX系统结构的研究%Research on Medium and Small IP PBX Architecture

    Institute of Scientific and Technical Information of China (English)

    章仁龙; 周宇

    2005-01-01

    IP PBX(PBX over IP)是VoIP(Voice over IP)领域内的一个研究热点.IP PBX将企业内部现有的数据网与电话网融合,是企业与公共交换电话网PSTN(Public Switched Telephone Network)、IP网等外部网络通信的桥梁.本文基于现有的多个IP PBX系统抽象出两种最常见的模型,并在此基础上改进后,提出了一种适合中小型IP PBX系统的结构模型.

  20. Measurement of Low Level Explosives Reaction in the Two-Dimensional Steven Impact Test

    Energy Technology Data Exchange (ETDEWEB)

    Forbes, J.W.; Tarver, C.M.; Chidester, S.K.; Garcia, F.; Greenwood, D.W.; Garza, R.

    2000-10-10

    The two-dimensional Steven impact test has been developed to be reproducible and amenable to computer modeling. This test has a hemispherical projectile traveling at tens of m/s impacting a metal cased explosive target. To assist in the understanding of this safety test, two-dimensional shock wave gauge techniques were used to measure the pressures of a few kilobars and times of reactions less than a millisecond. This work is in accord with a long-term goal to develop two-dimensional shock diagnostic techniques that are more than just time of arrival indicators. Experiments were performed where explosives were impacted at levels below shock initiation levels but caused low level reactions. Carbon foil and carbon resistor pressure gauges were used to measure pressures and time of events. The carbon resistor gauges indicate a late time low level reaction at 350 {micro}s after impact of the hemispherical projectile creating 0.5-6 kb peak shocks at the center of PBX 9501 (HMX/Estane/BDNPA-F; 95/2.5/2.5 wt %) explosive discs. The Steven test calculations are based on an ignition and growth criteria and found that the low level reaction occurs at 335 {micro}s, which is in good agreement with the experimental data. Some additional experiments simulating the Steven impact test were done on a gas gun with carbon foil and constantan strain gauges in a PMMA target. Hydrodynamic calculations can be used to evaluate the gauge performance in these experiments and check the lateral strain measurements.

  1. Kaliski's explosive driven fusion experiments

    International Nuclear Information System (INIS)

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

  2. Lidar Detection of Explosives Traces

    Science.gov (United States)

    Bobrovnikov, Sergei M.; Gorlov, Evgeny V.; Zharkov, Victor I.; Panchenko, Yury N.

    2016-06-01

    The possibility of remote detection of traces of explosives using laser fragmentation/laser-induced fluorescence (LF/LIF) is studied. Experimental data on the remote visualization of traces of trinitrotoluene (TNT), hexogen (RDX), trotyl-hexogen (Comp B), octogen (HMX), and tetryl with a scanning lidar detector of traces of nitrogen-containing explosives at a distance of 5 m are presented.

  3. Lidar Detection of Explosives Traces

    OpenAIRE

    Bobrovnikov Sergei M.; Gorlov Evgeny V.; Zharkov Victor I.; Panchenko Yury N.

    2016-01-01

    The possibility of remote detection of traces of explosives using laser fragmentation/laser-induced fluorescence (LF/LIF) is studied. Experimental data on the remote visualization of traces of trinitrotoluene (TNT), hexogen (RDX), trotyl-hexogen (Comp B), octogen (HMX), and tetryl with a scanning lidar detector of traces of nitrogen-containing explosives at a distance of 5 m are presented.

  4. Nanosensors for trace explosive detection

    Directory of Open Access Journals (Sweden)

    Larry Senesac

    2008-03-01

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

  5. Assessing nuclear explosions

    Science.gov (United States)

    Smith, Joseph V.

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

  6. Nucleosynthesis in stellar explosions

    Energy Technology Data Exchange (ETDEWEB)

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

    1983-01-01

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

  7. Nucleosynthesis in stellar explosions

    International Nuclear Information System (INIS)

    The final evolution and explosion of stars from 10 M/sub solar/ to 106 M/sub solar/ are reviewed with emphasis on factors affecting the expected nucleosynthesis. We order our paper in a sequence of decreasing mass. If, as many suspect, the stellar birth function was peaked towards larger masses at earlier times (see e.g., Silk 1977; but also see Palla, Salpeter, and Stahler 1983), this sequence of masses might also be regarded as a temporal sequence. At each stage of Galactic chemical evolution stars form from the ashes of preceding generations which typically had greater mass. A wide variety of Type I supernova models, most based upon accreting white dwarf stars, are also explored using the expected light curves, spectra, and nucleosynthesis as diagnostics. No clearly favored Type I model emerges that is capable of simultaneously satisfying all three constraints

  8. Mixing in explosions

    Energy Technology Data Exchange (ETDEWEB)

    Kuhl, A.L.

    1993-12-01

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

  9. NDE of explosion welded copper stainless steel first wall mock-up

    International Nuclear Information System (INIS)

    The study showed that reflection type C-mode scanning acoustic microscope (C-SAM) and internal ultrasonic inspection (IRIS) equipment can be applied for ultrasonic examination of copper stainless steel compound structures of ITER first wall mock-ups. Explosive welding can be applied to manufacture fully bonded copper stainless steel compound plates. However, explosives can be applied only for mechanical tightening of stainless steel cooling tubes within copper plate. If metallurgical bonding between stainless steel tubes and copper plate is required Hot Isostatic Pressing (HIP) method can be applied. (orig.)

  10. Optical detection of explosives: spectral signatures for the explosive bouquet

    Science.gov (United States)

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

    2009-05-01

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

  11. Cross Shear Roll Bonding

    DEFF Research Database (Denmark)

    Bay, Niels; Bjerregaard, Henrik; Petersen, Søren. B;

    1994-01-01

    The present paper describes an investigation of roll bonding an AlZn alloy to mild steel. Application of cross shear roll bonding, where the two equal sized rolls run with different peripheral speed, is shown to give better bond strength than conventional roll bonding. Improvements of up to 20......-23% in bond strength are found and full bond strength is obtained at a reduction of 50% whereas 65% is required in case of conventional roll bonding. Pseudo cross shear roll bonding, where the cross shear effect is obtained by running two equal sized rolls with different speed, gives the same results....

  12. Explosive signatures: Pre & post blast

    Science.gov (United States)

    Bernier, Evan Thomas

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

  13. Radiologic diagnosis of explosion casualties.

    Science.gov (United States)

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

    2008-01-01

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

  14. A clinical and laboratory study of TCF3-PBX1 positive adult acute lymphoblastic leukemia%TCF3-PBX1融合基因阳性成人急性淋巴细胞白血病的临床和实验研究

    Institute of Scientific and Technical Information of China (English)

    郑积富; 仇惠英; 潘金兰; 岑建农; 吴亚芳; 张俊; 吴德沛; 薛永权

    2010-01-01

    目的 探讨TCF3-PBX1融合基因阳性的成人急性淋巴细胞白血病(ALL)的形态学、免疫学、细胞遗传学和临床特点.方法采用R显带技术进行常规核型(CC)分析,间期荧光原位杂交(FISH)技术和RT-PCR技术检测TCF3-PBX1融合基因,流式细胞术(FCM)检测细胞免疫表型;分析19例TCF3-PBX1融合基因阳性成人ALL的临床和实验室特征并进行长期随访.结果本组19例TCF3-PBX1融合基因阳件ALL占同期成人ALL的3.13%;其中L_2 12例,L_2 7例.细胞遗传学检测7例为t(1;19)平衡易位,10例为der(19)t(1;19)不平衡易位,2例为正常核型.9例经RT-PCR检测的病例均有TCF3-PBX1融合基因转录本,17例经间期FISH检测TCF3-PBX1融合基因均为阳性.18例行FCM检测的患者中16例为B淋系抗原表达,2例为T淋系抗原表达.17例患者有不同程度的肝、脾、淋巴结等髓外浸润.本组患者经1个疗程诱导化疗后17例获得完全缓解(CR),CR率为94.7%,中位无复发生存时间为3.2个月,中位总生存期为7.2个月.结论 TCF3-PBX1融合基因阳件成人ALL有着独特的临床和实验室特点;治疗缓解率高,但短期内易复发,总生存期短,应该采取更积极的治疗以改善预后;间期双色FISH联合CC及RT-PCR可以提高TCF3-PBX1融合基因的检出率.%Objective To explore the morphology,immunophenotype,cytogenetics and clinical features of TCF3-PBX1 fusion gene positive adult acute lymphoblastic leukemia(ALL).Methods R banding was used to analyze conventional cytogenetics(CC),interphase fluorescence in situ hybridization(iFISH)and RT-PCR to detect the TCF3-PBX1 fusion gene,and flow cytometry to immunophenotype.The clinical and laboratory features and long-term follow-up of the patients were analyzed.Results The incidence of 19 TCF3-PBX1-positive adult ALL was 3.13% of total ALL patients.Of them,12 and 7 cases were diagnosed as L_1 and L_2 morphology respectively;7 cases with balanced translocation of chromosome 1 and 19;10 with

  15. Wire bonding in microelectronics

    CERN Document Server

    Harman, George G

    2010-01-01

    Wire Bonding in Microelectronics, Third Edition, has been thoroughly revised to help you meet the challenges of today's small-scale and fine-pitch microelectronics. This authoritative guide covers every aspect of designing, manufacturing, and evaluating wire bonds engineered with cutting-edge techniques. In addition to gaining a full grasp of bonding technology, you'll learn how to create reliable bonds at exceedingly high yields, test wire bonds, solve common bonding problems, implement molecular cleaning methods, and much more. Coverage includes: Ultrasonic bonding systems and technologies, including high-frequency systems Bonding wire metallurgy and characteristics, including copper wire Wire bond testing Gold-aluminum intermetallic compounds and other interface reactions Gold and nickel-based bond pad plating materials and problems Cleaning to improve bondability and reliability Mechanical problems in wire bonding High-yield, fine-pitch, specialized-looping, soft-substrate, and extreme-temperature wire bo...

  16. Active explosion barrier performance against methane and coal dust explosions

    Institute of Scientific and Technical Information of China (English)

    J J L du Plessis

    2015-01-01

    Preventing the propagation of methane or coal dust explosions through the use of active explosion-suppression systems remains one of the most underutilised explosion controls in underground coal mines. As part of the effort to develop better technologies to safeguard mines, the use of active barrier systems was investigated at Kloppersbos in South Africa. The system is designed to meet the requirements of the European Standard (EN 14591-4 2007) as well as the Mine Safety Standardisation in the Ministry of Coal Industry, Coal Industrial l Standard of the Peoples Republic of China (MT 694-1997). From the tests conducted, it can be concluded that the ExploSpot System was successful in stopping flame propagation for both methane and methane and coal dust hybrid explosions when ammonium phosphate powder was used as the suppression material. The use of this barrier will provide coal mine management with an additional explosion control close to the point of ignition and may find application within longwall faces further protecting mines against the risk of an explosion propagating throughout a mine.

  17. Retrofitting of RC Slabs Against Explosive Loads

    Institute of Scientific and Technical Information of China (English)

    WU Chengqing; OEHLERS Deric John; XIA Shaohua

    2006-01-01

    With the increase of terrorist bomb attacks on buildings,there is a need to develop advanced retrofitting techniques to strengthen structures against blast loads.Currently,several guidelines including an Australian version for retrofitting reinforced concrete (RC) structures are available for the design of retrofitting systems against seismic and monotonic loads using steel or fibre reinforced polymer (FRP) plates that can be either adhesively bonded to the surface or near surface mounted to the concrete cover.However,none of these guidelines provide advice suitable for retrofitting structures subjected to blast loads.In this paper,numerical models are used to simulate the performance of retrofitted RC slabs subjected to blast loads.Airblast pressure distributions on the surface of the slabs estimated in a previous study are used as input in the analysis.A material damage model developedpreviously for concrete and an elastoplastic model for steel bars are employed in this research for modelling reinforced concrete behaviour due to explosive loads.The material models and blast loading are coded into a finite element computer program LS-DYNA3D to do the analysis.With the numerical model,parametric studies are conducted to investigate RC slabs retrofitted by either externally bonded or near-surface mounted plates or GFRP sheets subjected to blast loads.Discussion is made on the effectiveness of the retrofitting system for RC slabs against blast loads.

  18. Explosive Contagion in Networks

    Science.gov (United States)

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

    2016-01-01

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

  19. Disaster management following explosion.

    Science.gov (United States)

    Sharma, B R

    2008-01-01

    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

  20. Furball Explosive Breakout Test

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, Joshua David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-08-05

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

  1. The Cambrian explosion.

    Science.gov (United States)

    Briggs, Derek E G

    2015-10-01

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

  2. Explosive Blast Neuropathology and Seizures

    Directory of Open Access Journals (Sweden)

    S. Krisztian eKovacs

    2014-04-01

    Full Text Available Traumatic brain injury (TBI due to explosive blast exposure is a leading combat casualty. It is also implicated as a key contributor to war related mental health diseases. A clinically important consequence of all types of TBI is a high risk for development of seizures and epilepsy. Seizures have been reported in patients who have suffered blast injuries in the Global War on Terror but the exact prevalence is unknown. The occurrence of seizures supports the contention that explosive blast leads to both cellular and structural brain pathology. Unfortunately, the exact mechanism by which explosions cause brain injury is unclear, which complicates development of meaningful therapies and mitigation strategies. To help improve understanding, detailed neuropathological analysis is needed. For this, histopathological techniques are extremely valuable and indispensable. In the following we will review the pathological results, including those from immunohistochemical and special staining approaches, from recent preclinical explosive blast studies.

  3. Suppression of stratified explosive interactions

    Energy Technology Data Exchange (ETDEWEB)

    Meeks, M.K.; Shamoun, B.I.; Bonazza, R.; Corradini, M.L. [Wisconsin Univ., Madison, WI (United States). Dept. of Nuclear Engineering and Engineering Physics

    1998-01-01

    Stratified Fuel-Coolant Interaction (FCI) experiments with Refrigerant-134a and water were performed in a large-scale system. Air was uniformly injected into the coolant pool to establish a pre-existing void which could suppress the explosion. Two competing effects due to the variation of the air flow rate seem to influence the intensity of the explosion in this geometrical configuration. At low flow rates, although the injected air increases the void fraction, the concurrent agitation and mixing increases the intensity of the interaction. At higher flow rates, the increase in void fraction tends to attenuate the propagated pressure wave generated by the explosion. Experimental results show a complete suppression of the vapor explosion at high rates of air injection, corresponding to an average void fraction of larger than 30%. (author)

  4. Explosion modelling for complex geometries

    Science.gov (United States)

    Nehzat, Naser

    A literature review suggested that the combined effects of fuel reactivity, obstacle density, ignition strength, and confinement result in flame acceleration and subsequent pressure build-up during a vapour cloud explosion (VCE). Models for the prediction of propagating flames in hazardous areas, such as coal mines, oil platforms, storage and process chemical areas etc. fall into two classes. One class involves use of Computation Fluid Dynamics (CFD). This approach has been utilised by several researchers. The other approach relies upon a lumped parameter approach as developed by Baker (1983). The former approach is restricted by the appropriateness of sub-models and numerical stability requirements inherent in the computational solution. The latter approach raises significant questions regarding the validity of the simplification involved in representing the complexities of a propagating explosion. This study was conducted to investigate and improve the Computational Fluid Dynamic (CFD) code EXPLODE which has been developed by Green et al., (1993) for use on practical gas explosion hazard assessments. The code employs a numerical method for solving partial differential equations by using finite volume techniques. Verification exercises, involving comparison with analytical solutions for the classical shock-tube and with experimental (small-scale, medium and large-scale) results, demonstrate the accuracy of the code and the new combustion models but also identify differences between predictions and the experimental results. The project has resulted in a developed version of the code (EXPLODE2) with new combustion models for simulating gas explosions. Additional features of this program include the physical models necessary to simulate the combustion process using alternative combustion models, improvement to the numerical accuracy and robustness of the code, and special input for simulation of different gas explosions. The present code has the capability of

  5. Ionic polarization-induced current-voltage hysteresis in CH3NH3PbX3 perovskite solar cells.

    Science.gov (United States)

    Meloni, Simone; Moehl, Thomas; Tress, Wolfgang; Franckevičius, Marius; Saliba, Michael; Lee, Yong Hui; Gao, Peng; Nazeeruddin, Mohammad Khaja; Zakeeruddin, Shaik Mohammed; Rothlisberger, Ursula; Graetzel, Michael

    2016-02-01

    CH3NH3PbX3 (MAPbX3) perovskites have attracted considerable attention as absorber materials for solar light harvesting, reaching solar to power conversion efficiencies above 20%. In spite of the rapid evolution of the efficiencies, the understanding of basic properties of these semiconductors is still ongoing. One phenomenon with so far unclear origin is the so-called hysteresis in the current-voltage characteristics of these solar cells. Here we investigate the origin of this phenomenon with a combined experimental and computational approach. Experimentally the activation energy for the hysteretic process is determined and compared with the computational results. First-principles simulations show that the timescale for MA(+) rotation excludes a MA-related ferroelectric effect as possible origin for the observed hysteresis. On the other hand, the computationally determined activation energies for halide ion (vacancy) migration are in excellent agreement with the experimentally determined values, suggesting that the migration of this species causes the observed hysteretic behaviour of these solar cells.

  6. Ionic polarization-induced current–voltage hysteresis in CH3NH3PbX3 perovskite solar cells

    Science.gov (United States)

    Meloni, Simone; Moehl, Thomas; Tress, Wolfgang; Franckevičius, Marius; Saliba, Michael; Lee, Yong Hui; Gao, Peng; Nazeeruddin, Mohammad Khaja; Zakeeruddin, Shaik Mohammed; Rothlisberger, Ursula; Graetzel, Michael

    2016-01-01

    CH3NH3PbX3 (MAPbX3) perovskites have attracted considerable attention as absorber materials for solar light harvesting, reaching solar to power conversion efficiencies above 20%. In spite of the rapid evolution of the efficiencies, the understanding of basic properties of these semiconductors is still ongoing. One phenomenon with so far unclear origin is the so-called hysteresis in the current–voltage characteristics of these solar cells. Here we investigate the origin of this phenomenon with a combined experimental and computational approach. Experimentally the activation energy for the hysteretic process is determined and compared with the computational results. First-principles simulations show that the timescale for MA+ rotation excludes a MA-related ferroelectric effect as possible origin for the observed hysteresis. On the other hand, the computationally determined activation energies for halide ion (vacancy) migration are in excellent agreement with the experimentally determined values, suggesting that the migration of this species causes the observed hysteretic behaviour of these solar cells. PMID:26852685

  7. Differential scanning calorimetry studies of Se85Te15-xPbx (x 4,6,8 and 10) glasses

    International Nuclear Information System (INIS)

    Results of differential scanning calorimetry (DSC) studies of Se85Te15-xPbx (x = 4, 6, 8 and 10) glasses have been reported and discussed in this paper. The results have been analyzed on the basis of structural relaxation equation, Matusita's equation and modified Kissinger's equation. The activation energies of structural relaxation lie in between 226 and 593 kJ/mol. The crystallization growth is found to be one-dimensional for all compositions. The activation energies of crystallization are found to be 100-136 kJ/mol by Matusita's equation while 102-139 kJ/mol by modified Kissinger's equation. The Hruby number (indicator of ease of glass forming and higher stability) is the highest for Se85Te9Pb6 glass while S factor (indicator of resistance to devitrification) is highest for Se85Te7Pb8 glass at all heating rates in our experiment. Further the highest resistance to devitrification has the highest value of structural activation energy and the activation energy of crystallization is maximum for the most stable glass by both Matusita's equation and the modified Kissinger's equation. (author)

  8. Intelligent OkiKoSenPBX1 Security Patrol Robot via Network and Map-Based Route Planning

    Directory of Open Access Journals (Sweden)

    Mbaïtiga Zacharie

    2009-01-01

    Full Text Available Problem statement: With an increased demand for security and limited numbers of trained security personnel, some security mangers have a lot of ground to police and limited staff to cover it. To compensate for shortages of security staff and to reduce the stress of security managers, we have developed an intelligent patrol robot system called "OkiKoSenPBX1". The system integrates a variety of sensors to gather environmental information and to detect abnormal events including intruders. Approach: In our approach, the route planning procedure was based on determining a sequence of intermediary goal points or coordinates x and y composing the robot trajectory. Results: A qualitative running experimental evaluation had been performed on the 1st floor of the Okinawa national college of technology as a preliminary practical implementation and its real-time performance was excellent, where a student like-guard can take control of the camera pan and tilt functions remotely. Conclusion: The real-time performance of the developed system that can leave security personnel hands-free for other important tasks is an irresistible system that can be put into practical use in a public offices facility, manufacturing facilities and various construction sites-everywhere there’s a need for advanced frontline security.

  9. Lidar Detection of Explosives Traces

    Directory of Open Access Journals (Sweden)

    Bobrovnikov Sergei M.

    2016-01-01

    Full Text Available The possibility of remote detection of traces of explosives using laser fragmentation/laser-induced fluorescence (LF/LIF is studied. Experimental data on the remote visualization of traces of trinitrotoluene (TNT, hexogen (RDX, trotyl-hexogen (Comp B, octogen (HMX, and tetryl with a scanning lidar detector of traces of nitrogen-containing explosives at a distance of 5 m are presented.

  10. On Bond Portfolio Management

    OpenAIRE

    Vladislav Kargin

    2002-01-01

    This paper describes a new method of bond portfolio optimization based on stochastic string models of correlation structure in bond returns. The paper shows how to approximate correlation function of bond returns, compute the optimal portfolio allocation using Wiener-Hopf factorization, and check whether a collection of bonds presents arbitrage opportunities.

  11. Simulation Analysis of Indoor Gas Explosion Damage

    Institute of Scientific and Technical Information of China (English)

    钱新明; 陈林顺; 冯长根

    2003-01-01

    The influence factors and process of indoor gas explosion are studied with AutoReaGas explosion simulator. The result shows that venting pressure has great influence on the indoor gas explosion damage. The higher the venting pressure is, the more serious the hazard consequence will be. The ignition location has also evident effect on the gas explosion damage. The explosion static overpressure would not cause major injury to person and serious damage to structure in the case of low venting pressure (lower than 2 kPa). The high temperature combustion after the explosion is the major factor to person injury in indoor gas explosion accidents.

  12. Tagging of Explosives for Detection

    Directory of Open Access Journals (Sweden)

    J. S. Gharia

    2000-01-01

    Full Text Available This paper gives the results of a study on estimation of shelf life of2,3-dimethyI2,3-dinitrobutane (DMNB-tagged RDX and PETN expiosives by monitoring DMNB depletion by high performanceliquid chromatography and simultaneously recording the detectability of the tagged explosive composition using explosive vapoUf detector Model-97 HS. DMNB was incorporated in the explosive using methanol as solvent for DMNB and the explosive compositions were stored at 35,55 and 75 °C over a long period. Methods developed for preparing the homogeneously tagged composition with DMNB at 0.5 per cent level and for the analysis ofDMNB for ensuring homogeneity of DMNB in the composition are described. The results show no change in compatibility and sensitivity on the incorporation of DMNB in the explosive. Estimation of shelf life of DMNB in the explosive was done for a period of storage of 202-304 days at different temperatures.

  13. Fessibility Study on Nitrogen in Explosives using X-ray Photoelectron Spectroscopy: Chemical Fertilizer

    International Nuclear Information System (INIS)

    It was known that an explosive is defined as a material which contains a large amount of energy stored in chemical bonds. The energetic stability of gaseous products, and hence, their generation come from the strong bond formation of carbon (mono/di)oxide and (di)nitrogen. Consequently, most commercial explosives are contained -NO2, -ONO2 and/or -NHNO2 groups which when detonated release gases like the aforementioned ones, e.g., nitroglycerin, TNT, HMX, PETN, nitrocellulose, etc. It was revealed that the elemental compositions, especially N was found in most of the explosive and fertilizer. Chemical fertilizers that used as explosive stimulants were analyzed using X-ray photoelectron spectroscopy (XPS) and scanning electron microscope coupled with energy-dispersive X-ray fluorescence spectroscopy (SEM-EDS). XPS spectra showed relatively high amount of nitrogen (N) in the various samples, especially sample #6 and #7. In addition, the elemental analysis revealed the presence of trace elements. Explosives and fertilizers have differences in specific compositions. It can be concluded that these methods seem to be used as a fingerprint examination to identify various kinds of explosives and fertilizers.

  14. Metallic glass coating on metals plate by adjusted explosive welding technique

    International Nuclear Information System (INIS)

    Using an adjusted explosive welding technique, an aluminum plate has been coated by a Fe-based metallic glass foil in this work. Scanning electronic micrographs reveal a defect-free metallurgical bonding between the Fe-based metallic glass foil and the aluminum plate. Experimental evidence indicates that the Fe-based metallic glass foil almost retains its amorphous state and mechanical properties after the explosive welding process. Additionally, the detailed explosive welding process has been simulated by a self-developed hydro-code and the bonding mechanism has been investigated by numerical analysis. The successful welding between the Fe-based metallic glass foil and the aluminum plate provides a new way to obtain amorphous coating on general metal substrates.

  15. Crystal structure and explosive performance of a new CL-20/caprolactam cocrystal

    Science.gov (United States)

    Guo, Changyan; Zhang, Haobin; Wang, Xiaochuan; Xu, Jinjiang; Liu, Yu; Liu, Xiaofeng; Huang, Hui; Sun, Jie

    2013-09-01

    Co-crystallization is an effective way to improve performance of the high explosive 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane (CL-20). A new CL-20/caprolactam (CPL) cocrystal has been prepared by a rapid solvent evaporation method, and the crystal structure investigations show that the cocrystal is formed by strong intermolecular hydrogen bond interaction. The cocrystal can only be prepared with low moisture content of the air, because water in the air has a profound effect on the cocrystal formation, and it can lead to crystal form conversion of CL-20, but not the formation of cocrystal. The CL20/CPL explosive possess very low sensitivity, and may be used as additive in explosives formulation to desensitize other high explosives.

  16. Microstructure and Martensitic Transformation Behaviors of Explosively Welded NiTi/NiTi Laminates

    Institute of Scientific and Technical Information of China (English)

    YAN Zhu; CUI Li-shan; ZHENG Yan-jun

    2007-01-01

    The study is a first attempt to prepare bulk NiTi/NiTi shape memory alloy (SMA) laminates with a macroscopic heterogeneous composition by explosive welding and investigate their microstructures and martensitic transformation behaviors. After explosive welding, a perfect interfacial bonding between the two components and a reversible martensitic transformation are realized in the tandem.Results show achievement of a fine granular structure and the maximum value of microhardness near the welding interface because of the excessive cold plastic deformation and the high impact velocity during the explosive welding. Meanwhile, the effects of aging on the transformation of the welded tandem are investigated by differential scanning calorimeter (DSC) and subject to discussion. The transformation temperatures of NiTi/NiTi SMAs increase with the rise of the aging temperature. The experimental results indicate the shape memory properties of NiTi/NiTi SMA fabricated by explosive welding can be improved by optimizing the aging technology.

  17. THE INFLUENCE OF BARRIERS ON FLAME AND EXPLOSION WAVE IN GAS EXPLOSION

    Institute of Scientific and Technical Information of China (English)

    林柏泉; 周世宁; 张仁贵

    1998-01-01

    This paper researches into the influence of barriers on flame and explosion wave in gasexplosion on the basis of experiment. The result shows that the barrier is very important to thetransmission of flame and explosion wave in gas explosion. When there are barriers, the speed oftransmission would be very fast and shock wave will appear in gas explosion, which would in-crease gas explosion power. The result of research is very important to prevent gas explosion anddecrease the power of it.

  18. PBX炸药粘弹性损伤本构模型的参数识别%PARAMETER IDENTIFICATION FOR VISCOELASTIC DAMAGE CONSTITUTIVE MODEL OF PBX

    Institute of Scientific and Technical Information of China (English)

    高军; 黄再兴

    2013-01-01

    A viscoelastic damage model for PBX based on Visco-scram equations is established by introducing an internal variable for damage characterizing microscopic defects in materials.The model is implemented into finite element software ABAQUS through user subroutines interface UMAT provided by ABAQUS.Combining the forward computation based on ABAQUS and the genetic optimization algorithm,an inverse technique is advanced to identify the parameters of a viscoelastic damage constitutive model for PBX.An example is carried out using the proposed technique.The results show that the technique is feasible for the parameters identification of a PBX viscoelastic damage model,and it can be applied to the parameter identification of other models.%利用损伤力学的方法,通过引入表征材料内部细观缺陷的损伤内变量,建立了基于Visco-scram方程的PBX粘弹性损伤本构模型,并利用子程序接口将模型引入到有限元软件ABAQUS中.结合ABAQUS正演计算和遗传优化算法,建立了PBX粘弹性损伤本构模型参数识别的方法.进行了PBX粘弹性损伤本构模型参数的识别仿真,结果证明了所建立的方法对识别PBX粘弹性损伤本构模型参数的可行性,同时此方法也可以被应用到其他本构模型参数的识别中.

  19. Hydrogen bonded supramolecular structures

    CERN Document Server

    Li, Zhanting

    2015-01-01

    This book covers the advances in the studies of hydrogen-bonding-driven supramolecular systems  made over the past decade. It is divided into four parts, with the first introducing the basics of hydrogen bonding and important hydrogen bonding patterns in solution as well as in the solid state. The second part covers molecular recognition and supramolecular structures driven by hydrogen bonding. The third part introduces the formation of hollow and giant macrocycles directed by hydrogen bonding, while the last part summarizes hydrogen bonded supramolecular polymers. This book is designed to b

  20. Explosion limits for combustible gases

    Institute of Scientific and Technical Information of China (English)

    TONG Min-ming; WU Guo-qing; HAO Ji-fei; DAI Xin-lian

    2009-01-01

    Combustible gases in coal mines are composed of methane, hydrogen, some multi-carbon alkane gases and other gases. Based on a numerical calculation, the explosion limits of combustible gases were studied, showing that these limits are related to the concentrations of different components in the mixture. With an increase of C4H10 and C6H14, the Lower ExplosionLimit (LEL) and Upper Explosion-Limit (UEL) of a combustible gas mixture will decrease clearly. For every 0.1% increase in C4H10 and C6H14, the LEL decreases by about 0.19% and the UEL by about 0.3%. The results also prove that, by increasing the amount of H2, the UEL of a combustible gas mixture will increase considerably. If the level of H2 increases by 0.1%, the UEL will increase by about 0.3%. However, H2 has only a small effect on the LEL of the combustible gas mixture. Our study provides a theoretical foundation for judging the explosion risk of an explosive gas mixture in mines.

  1. The Quiet Explosion

    Science.gov (United States)

    2008-07-01

    A European-led team of astronomers are providing hints that a recent supernova may not be as normal as initially thought. Instead, the star that exploded is now understood to have collapsed into a black hole, producing a weak jet, typical of much more violent events, the so-called gamma-ray bursts. The object, SN 2008D, is thus probably among the weakest explosions that produce very fast moving jets. This discovery represents a crucial milestone in the understanding of the most violent phenomena observed in the Universe. Black Hole ESO PR Photo 23a/08 A Galaxy and two Supernovae These striking results, partly based on observations with ESO's Very Large Telescope, will appear tomorrow in Science Express, the online version of Science. Stars that were at birth more massive than about 8 times the mass of our Sun end their relatively short life in a cosmic, cataclysmic firework lighting up the Universe. The outcome is the formation of the densest objects that exist, neutron stars and black holes. When exploding, some of the most massive stars emit a short cry of agony, in the form of a burst of very energetic light, X- or gamma-rays. In the early afternoon (in Europe) of 9 January 2008, the NASA/STFC/ASI Swift telescope discovered serendipitously a 5-minute long burst of X-rays coming from within the spiral galaxy NGC 2770, located 90 million light-years away towards the Lynx constellation. The Swift satellite was studying a supernova that had exploded the previous year in the same galaxy, but the burst of X-rays came from another location, and was soon shown to arise from a different supernova, named SN 2008D. Researchers at the Italian National Institute for Astrophysics (INAF), the Max-Planck Institute for Astrophysics (MPA), ESO, and at various other institutions have observed the supernova at great length. The team is led by Paolo Mazzali of INAF's Padova Observatory and MPA. "What made this event very interesting," says Mazzali, "is that the X-ray signal was very

  2. AC conductivity, dielectric and impedance studies of Cd0.8−xPbxZn0.2S mixed semiconductor compounds

    International Nuclear Information System (INIS)

    Graphical abstract: A plot of 1−s versus T (K) for Cd0.8−xPbxZn0.2S (x = 0, 0.1–0.8), inset: plot of s versus T (K) for x = 0. - Highlights: • Activation energy of relaxation process of Cd0.8−xPbxZn0.2S (x = 0, 0.1–0.8) compounds has been determined. • Grain resistances and grain capacitances of the compounds were estimated at different temperatures. • Relaxation time for all the compounds has been determined at different temperatures. - Abstract: The samples of Cd0.8−xPbxZn0.2S (x = 0, 0.1–0.8) are prepared by Controlled Co-Precipitation Method. X-ray diffraction studies have confirmed the polycrystalline nature of the samples with Hexagonal and Cubic phases of Wurtzite structure. AC conductivity (σac) measurements of Cd0.8−xPbxZn0.2S samples at different temperatures (between 40 and 300 °C), in the frequency range 5 kHz–20 MHz were made. The results showed that σac obeys the relation σac(ω) = Aωs. The exponent “s” was found to decrease with increase in temperature. Further analysis revealed that, the AC conductivity of the samples follow correlated barrier hopping (CBH) model. The dielectric constant (∊′) and dielectric loss (Tan δ) were observed to (i) increase with the increase in temperature and the increase is higher at lower frequencies and (ii) decrease rapidly at low frequencies and remains almost constant at higher frequencies. The cole–cole plot showed a single semicircle, indicating an equivalent circuit with a single parallel resistor Rg and capacitance Cg network with a series resistance Rs. The plots also show the grain contribution toward AC conductivity. The relaxation frequencies, determined from these plots are used to calculate the activation energies Ea of relaxation process using Log τ versus 103/T plots. The values of Ea for all the studied compounds range from 0.05 to 0.28 eV and the results are explained based on the defects formed due to the addition of Pb into the Cd0.8Zn0.2S compound

  3. Structure and switching of in-plane ferroelectric nano-domains in strained PbxSr1-xTiO3 thin films

    Energy Technology Data Exchange (ETDEWEB)

    Matzen, Sylivia [University of Groningen, The Netherlands; Nesterov, Okeksiy [ORNL; Rispens, Gregory [University of Groningen, The Netherlands; Heuver, J. A. [University of Groningen, The Netherlands; Bark, C [University of Wisconsin, Madison; Biegalski, Michael D [ORNL; Christen, Hans M [ORNL; Noheda, Beatriz [University of Groningen, The Netherlands

    2014-01-01

    Nanoscale ferroelectrics, the active elements of a variety of nanoelectronic devices, develop denser and richer domain structures than the bulk counterparts. With shrinking device sizes understanding and controlling domain formation in nanoferroelectrics is being intensely studied. Here we show that a precise control of the epitaxy and the strain allows stabilizing a hierarchical domain architecture in PbxSr1-xTiO3 thin films, showing periodic, purely in-plane polarized, ferroelectric nano-domains that can be switched by a scanning probe.

  4. Ferroelectric domains in epitaxial PbxSr1−xTiO3 thin films investigated using X-ray diffraction and piezoresponse force microscopy

    Directory of Open Access Journals (Sweden)

    S. Fernandez-Peña

    2016-08-01

    Full Text Available We present a detailed study of compressively strained PbxSr1−xTiO3 thin films grown by off-axis radio frequency magnetron sputtering on (001-oriented Nb-doped SrTiO3 substrates. Film tetragonality and the ferroelectric critical temperatures are measured for samples of different composition and thickness and compared with a phenomenological Landau-Devonshire model. 180∘ ferroelectric domains are observed using both X-ray diffraction and piezoresponse force microscopy and domain sizes obtained by the two techniques are compared and discussed.

  5. Growth of epitaxial Pt1-xPbx alloys by surface limited redox replacement and study of their adsorption properties.

    Science.gov (United States)

    Mercer, M P; Plana, D; Fermίn, D J; Morgan, D; Vasiljevic, N

    2015-10-01

    The surface limited redox replacement (SLRR) method has been used to design two-dimensional Pt-Pb nanoalloys with controlled thickness, composition, and structure. The electrochemical behavior of these alloys has been systematically studied as a function of alloy composition. A single-cell, two-step SLRR protocol based on the galvanic replacement of underpotentially deposited monolayers of Pb with Pt was used to grow epitaxial Pt1-xPbx (x up to 10 ML thickness on Au substrates. It is shown that by varying the terminating potential of the galvanic replacement step, the Pb atomic content can be controlled in the films. Electrochemical analysis of the alloys showed that the adsorption of both H and CO exhibits similar, and systematic, decreases with small increases in the Pb content. These measurements, commonly used in electrocatalysis for the determination of active surface areas of Pt, suggested area values much lower than those expected based on the net Pt composition in the alloy as measured by XPS. These results show that Pb has a strong screening effect on the adsorption of both H and CO. Moreover, changes in alloy composition result in a negative shift in the potential of the peaks of CO oxidation that scales with the increase of Pb content. The results suggest electronic and bifunctional effects of incorporated Pb on the electrochemical behavior of Pt. The study illustrates the potential of the SLRR methodology, which could be employed in the design of 2-dimensional bimetallic Pt nanoalloys for fundamental studies of electrocatalytic behavior in fuel cell reactions dependent on the nature of alloying metal and its composition. PMID:26372676

  6. Coulomb explosion of "hot spot"

    CERN Document Server

    Oreshkin, V I; Chaikovsky, S A; Artyomov, A P

    2016-01-01

    The study presented in this paper has shown that the generation of hard x rays and high-energy ions, which are detected in pinch implosion experiments, may be associated with the Coulomb explosion of the hot spot that is formed due to the outflow of the material from the pinch cross point. During the process of material outflow, the temperature of the hot spot plasma increases, and conditions arise for the plasma electrons to become continuously accelerated. The runaway of electrons from the hot spot region results in the buildup of positive space charge in this region followed by a Coulomb explosion. The conditions for the hot spot plasma electrons to become continuously accelerated have been revealed and estimates have been obtained for the kinetic energy of the ions generated by the Coulomb explosion.

  7. Seismic coupling of nuclear explosions

    International Nuclear Information System (INIS)

    The new Giant Magnet Experimental Facility employing digital recording of explosion induced motion has been constructed and successfully tested. Particle velocity and piezoresistance gage responses can be measured simultaneously thus providing the capability for determining the multi-component stress-strain history in the test material. This capability provides the information necessary for validation of computer models used in simulation of nuclear underground testing, chemical explosion testing, dynamic structural response, earth penetration response, and etc. This report discusses fully coupled and cavity decoupled explosions of the same energy (0.622 kJ) were carried out as experiments to study wave propagation and attenuation in polymethylmethacrylate (PMMA). These experiments produced particle velocity time histories at strains from 2 x 10-3 to as low as 5.8 x 10-6. Other experiments in PMMA, reported recently by Stout and Larson8 provide additional particle velocity data to strains of 10-1

  8. Evidence for Nearby Supernova Explosions

    CERN Document Server

    Benítez, N; Canelles, M; Benitez, Narciso; Maiz-Apellaniz, Jesus; Canelles, Matilde

    2002-01-01

    Supernova explosions are one of the most energetic--and potentially lethal--phenomena in the Universe. Scientists have speculated for decades about the possible consequences for life on Earth of a nearby supernova, but plausible candidates for such an event were lacking. Here we show that the Scorpius-Centaurus OB association, a group of young stars currently located at~130 parsecs from the Sun, has generated 20 SN explosions during the last 11 Myr, some of them probably as close as 40 pc to our planet. We find that the deposition on Earth of 60Fe atoms produced by these explosions can explain the recent measurements of an excess of this isotope in deep ocean crust samples. We propose that ~2 Myr ago, one of the SNe exploded close enough to Earth to seriously damage the ozone layer, provoking or contributing to the Pliocene-Pleistocene boundary marine extinction.

  9. Optimal dynamic detection of explosives

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-01-01

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

  10. Explosion Clad for Upstream Oil and Gas Equipment

    Science.gov (United States)

    Banker, John G.; Massarello, Jack; Pauly, Stephane

    2011-01-01

    Today's upstream oil and gas facilities frequently involve the combination of high pressures, high temperatures, and highly corrosive environments, requiring equipment that is thick wall, corrosion resistant, and cost effective. When significant concentrations of CO2 and/or H2S and/or chlorides are present, corrosion resistant alloys (CRA) can become the material of choice for separator equipment, piping, related components, and line pipe. They can provide reliable resistance to both corrosion and hydrogen embrittlement. For these applications, the more commonly used CRA's are 316L, 317L and duplex stainless steels, alloy 825 and alloy 625, dependent upon the application and the severity of the environment. Titanium is also an exceptional choice from the technical perspective, but is less commonly used except for heat exchangers. Explosion clad offers significant savings by providing a relatively thin corrosion resistant alloy on the surface metallurgically bonded to a thick, lower cost, steel substrate for the pressure containment. Developed and industrialized in the 1960's the explosion cladding technology can be used for cladding the more commonly used nickel based and stainless steel CRA's as well as titanium. It has many years of proven experience as a reliable and highly robust clad manufacturing process. The unique cold welding characteristics of explosion cladding reduce problems of alloy sensitization and dissimilar metal incompatibility. Explosion clad materials have been used extensively in both upstream and downstream oil, gas and petrochemical facilities for well over 40 years. The explosion clad equipment has demonstrated excellent resistance to corrosion, embrittlement and disbonding. Factors critical to insure reliable clad manufacture and equipment design and fabrication are addressed.

  11. Australia's Bond Home Bias

    OpenAIRE

    Mishra, Anil V; Umaru B. Conteh

    2014-01-01

    This paper constructs the float adjusted measure of home bias and explores the determinants of bond home bias by employing the International Monetary Fund's high quality dataset (2001 to 2009) on cross-border bond investment. The paper finds that Australian investors' prefer investing in countries with higher economic development and more developed bond markets. Exchange rate volatility appears to be an impediment for cross-border bond investment. Investors prefer investing in countries with ...

  12. Bond percolation in films

    Science.gov (United States)

    Korneta, W.; Pytel, Z.

    1988-04-01

    Bond percolation in films with simple cubic structure is considered. It is assumed that the probability of a bond being present between nearest-neighbor sites depends on the distances to surfaces. Based on the relation between the Potts model and the bond percolation model, and using the mean-field approximation, the phase diagram and profiles of the percolation probability have been obtained.

  13. Corporate Bonds in Denmark

    DEFF Research Database (Denmark)

    Tell, Michael

    2015-01-01

    to think in alternative ways such as issuing corporate bonds. A market for corporate bonds exists in countries such as Norway, Germany, France, the United Kingdom and the United States, while Denmark is still behind in this trend. Some large Danish corporations have instead used foreign corporate bonds...

  14. Chemical bond fundamental aspects of chemical bonding

    CERN Document Server

    Frenking, Gernot

    2014-01-01

    This is the perfect complement to ""Chemical Bonding - Across the Periodic Table"" by the same editors, who are two of the top scientists working on this topic, each with extensive experience and important connections within the community. The resulting book is a unique overview of the different approaches used for describing a chemical bond, including molecular-orbital based, valence-bond based, ELF, AIM and density-functional based methods. It takes into account the many developments that have taken place in the field over the past few decades due to the rapid advances in quantum chemica

  15. Bonding thermoplastic polymers

    Science.gov (United States)

    Wallow, Thomas I.; Hunter, Marion C.; Krafcik, Karen Lee; Morales, Alfredo M.; Simmons, Blake A.; Domeier, Linda A.

    2008-06-24

    We demonstrate a new method for joining patterned thermoplastic parts into layered structures. The method takes advantage of case-II permeant diffusion to generate dimensionally controlled, activated bonding layers at the surfaces being joined. It is capable of producing bonds characterized by cohesive failure while preserving the fidelity of patterned features in the bonding surfaces. This approach is uniquely suited to production of microfluidic multilayer structures, as it allows the bond-forming interface between plastic parts to be precisely manipulated at micrometer length scales. The bond enhancing procedure is easily integrated in standard process flows and requires no specialized equipment.

  16. Dielectric Properties of La2O3 Doped Composite (PbxSr1−xTiO3 Borosilicate Glass Ceramic

    Directory of Open Access Journals (Sweden)

    C. R. Gautam

    2013-01-01

    Full Text Available Ferroelectric (PbxSr1−xTiO3 (PST perovskite phase has been crystallized in borosilicate glassy matrix with a suitable choice of composition and heat treatment schedule. La2O3 is a donor dopant for PST and can make it semiconducting. Dispersion of semiconducting perovskite phase in insulating glassy matrix in glass-ceramic samples may lead to the formation of space charge polarization around crystal-glass interface, leading to a high value of effective dielectric constant, εr. Therefore, with the aim of the developing glass ceramics with high dielectric constant, glasses in the system 64[(PbxSr1−xO·TiO2]-25[2SiO2·B2O3]-5[K2O]-5[BaO]-1[La2O3] have been prepared (0.5≤x≤1. It is found that the addition of La2O3 strongly affected the crystallization and dielectric behavior of glass-ceramic with PST perovskite phase. All glass ceramic samples show a diffuse broad Curie peak in their εr versus T plots. Curie peak temperature, Tc, depends on compositions of the glass-ceramic samples as well as frequency of measurements.

  17. Efficient blue up-conversion luminescence of Tm3+ ions in transparent oxyfluoride glass ceramics containing Pbx Cd1-x F2 nanocrystals

    International Nuclear Information System (INIS)

    Oxyfluoride glasses were developed in the 30SiO2 · 15AlO1.5 · 28PbF2 · 22CdF2 · (4.8 - y)GdF3 · 0.1NdF3 · yYbF3 · 0.1TmF3 (y 0, 0.1, 0.2, 0.5, 1, 2, 3, 4 and 4.8) composition, in mol%. X-ray diffraction analysis revealed that heat treatments of the oxyfluoride glasses cause the precipitation of (Nd3+, Yb3+, Tm3+)-doped fluorite-type Pbx Cd1-x F2 nanocrystals of about 17.8 nm diameter in a glass matrix. Very strong blue up-conversion luminescence which can be assigned to the Tm3+ :1 G4 →3 H6 transition under 800 nm excitation was observed in these transparent glass ceramics. The intensity of the blue up-conversion luminescence is strongly dependent on the precipitation of Pbx Cd1-x F2 crystals and the YbF3 concentration. The reasons for the highly efficient Tm3+ up-conversion luminescence are discussed. An energy transfer process and an up-conversion mechanism in the glass and glass ceramics are also proposed

  18. Structural evolution and physical properties of multiferroic Bi0.9−xLa0.1PbxFeO3−x/2 ceramics

    International Nuclear Information System (INIS)

    The polycrystalline samples of multiferroic Bi0.9−xLa0.1PbxFeO3−x/2 (x = 0–0.35) were prepared by the solid state reaction method and characterized by x-ray diffraction, field emission scanning electron microscopy, dielectric, magnetic, magnetodielectric (MD) and magnetoelectric (ME) measurements. A structural evolution from rhombohedral to pseudocubic structure was found to happen near x = 0.20. The changes and anomalies observed in magnetization were correlated with structural evolution and the development in microstructure. The ferroelectromagnetic measurements demonstrated Pb2+ doping to be a very effective method to realize the coexistence of weak ferromagnetism and ferroelectric in the ferroelectric R3c phase of BiFeO3. The MD and ME effects of Bi0.9−xLa0.1PbxFeO3−x/2 ceramics were first reported. A maximum ME voltage coefficient has been observed at x = 0.30. This work is helpful for understanding the ferroelectromagnetic behaviors and ME effect with complicated spin structures. (paper)

  19. Lead-free primary explosives

    Science.gov (United States)

    Huynh, My Hang V.

    2010-06-22

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

  20. Explosion mitigation by water mist

    NARCIS (Netherlands)

    Wal, R. van der; Cargill, S.; Longbottom, A.; Rhijnsburger, M.P.M.; Erkel, A.G. van

    2010-01-01

    The internal explosion of an anti-ship missile or stored ammunition is a potentially catastrophic threat for a navy vessel. These events generally cause heavy blast loading and fragments to perforate the ship structure. As a solution to reduce the blast loading, the compartment can be filled with wa

  1. Turbulent Combustion in SDF Explosions

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-11-12

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

  2. Episodic Explosions in Interstellar Ices

    CERN Document Server

    Rawlings, J M C; Viti, S; Cecchi-Pestellini, C

    2013-01-01

    We present a model for the formation of large organic molecules in dark clouds. The molecules are produced in the high density gas-phase that exists immediately after ice mantles are explosively sublimated. The explosions are initiated by the catastrophic recombination of trapped atomic hydrogen. We propose that, in molecular clouds, the processes of freeze-out onto 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 timescale 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...

  3. Explosive micro-bubble actuator

    NARCIS (Netherlands)

    Broek, van den D.M.; Elwenspoek, M.

    2008-01-01

    Explosive evaporation occurs when a liquid is exposed to extremely high heat-fluxes. Within a few microseconds a bubble in the form vapour film is generated, followed by rapid growth due to the pressure impulse and finally the bubbles collapse. This effect, which already has proven its use in curren

  4. Explosive micro-bubble actuator

    NARCIS (Netherlands)

    Broek, van den D.M.; Elwenspoek, M.C.

    2007-01-01

    Explosive evaporation occurs when a thin layer of liquid reaches a very high temperature in a very short time. At these temperatures homogeneous nucleation takes place. The nucleated bubbles almost instantly coalesce forming a vapour film followed by rapid growth due to the pressure impulse and fina

  5. Statistical estimation of loads from gas explosions

    OpenAIRE

    Høiset, Stian

    1998-01-01

    In the design of structures in the offshore and process industries, the possibility of a gas explosion must always be considered. This is usually incorporated by performing explosion simulations. However, estimations based on such calculations introduce uncertainties in the design process. The main uncertainties in explosion simulations are the assumption of the gas cloud,the location of the ignition point and the properties of the explosion simulator itself. In this thesis, we try to investi...

  6. Molecular Dynamic Simulation for HMX/NTO Supramolecular Explosive

    Institute of Scientific and Technical Information of China (English)

    林鹤; 朱顺官; 张琳; 彭新华; 李洪珍; 陈阳

    2012-01-01

    Based on the crystal engineering, six models of octahydro-1,3 ,5 ,7-tetranitro-1,3 ,5 ,7-tetrazocine ( HMX )/3-nitro-1,2,4-triazol-5-one(NTO) supramolecular explosive were designed. The probable formation of HMX/NTO supramolecular explosive was investigated by the molecular dynamic (MD) method. Interaction between oxygen atoms in HMX and hydrogen atoms in NTO or between hydrogen atoms in HMX and oxygen atoms in NTO were studied by the radial distribution function (RDF). It shows that there are strong hydrogen bonds and Van Der Waals forces between HMX and NTO, in which the hydrogen bonds between oxygen atoms in the NTO and hydrogen atoms in HMX are the main host-guest interactions. The distributions of bond length, bond angle and dihedral angle were simulated by MD. It shows that the structure of HMX is seriously distorted. The binding energies and X-ray powder diffraction (XRD) patterns were calculated on the basis of the final HMX/NTO supramolecular structures. The results show that the binding energies of six supramolecular models are Ebinding (1 1 1) 〉E binding (1 0 0) 〉E binding (0 2 0) 〉E binding (random) 〉Ebinding (1 0 2) 〉 Ebinding(0 1 1), and the XRD patterns of six supramolecular models are quite different from pure HMX or NTO. Based on the investigation for growth morphology, binding energies and RDF, the model of HMX supercell substituted by NTO along the ( 1 1 1 ) surface of HMX is easier to form.

  7. 30 CFR 77.1301 - Explosives; magazines.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Explosives; magazines. 77.1301 Section 77.1301... and Blasting § 77.1301 Explosives; magazines. (a) Detonators and explosives other than blasting agents shall be stored in magazines. (b) Detonators shall not be stored in the same magazine with...

  8. 77 FR 55108 - Explosive Siting Requirements

    Science.gov (United States)

    2012-09-07

    ... where solid propellants, energetic liquids, or other explosives are located to prepare launch vehicles... locations and facilities at a launch site where solid propellants, liquid propellants or other explosives... a launch site where solid propellants, energetic liquids, or other explosives are stored or...

  9. 14 CFR 420.63 - Explosive siting.

    Science.gov (United States)

    2010-01-01

    ... launch site boundary; (2) A listing of the maximum quantities of liquid and solid propellants and other explosives to be located at each explosive hazard facility, including the class and division for each solid explosive and the hazard and compatibility group for each liquid propellant; and (3) A description of...

  10. Numerical computation algorithm of explosion equations and thermodynamics parameters of mine explosives

    Institute of Scientific and Technical Information of China (English)

    李守巨; 刘迎曦; 何翔; 周圆π

    2001-01-01

    A new numerical algorithm is presented to simulate the explosion reaction process of mine explosives based on the equation of state, the equation of mass conservation and thermodynamics balance equation of explosion products. With the affection of reversible reaction of explosion products to explosion reaction equations and thermodynamics parameters considered, the computer program has been developed. The computation values show that computer simulation results are identical with the testinq ones.

  11. Numerical computation algorithm of explosion equations and thermodynamics parameters of mine explosives

    Institute of Scientific and Technical Information of China (English)

    LI Shou-ju; LIU Ying-xi; HE Xiang; ZHOU Y uan-pai

    2001-01-01

    A new numerical algorithm is presented to simulate the explosion reacti on process of mine explosives based on the equation of state, the equation of ma ss conservation and thermodynamics balance equation of explosion products. With the affection of reversible reaction of explosion products to explosion reaction equations and thermodynamics parameters considered, the computer program has be en developed. The computation values show that computer simulation results are i dentical with the testing ones.

  12. Weak bond screening system

    Science.gov (United States)

    Chuang, S. Y.; Chang, F. H.; Bell, J. R.

    Consideration is given to the development of a weak bond screening system which is based on the utilization of a high power ultrasonic (HPU) technique. The instrumentation of the prototype bond strength screening system is described, and the adhesively bonded specimens used in the system developmental effort are detailed. Test results obtained from these specimens are presented in terms of bond strength and level of high power ultrasound irradiation. The following observations were made: (1) for Al/Al specimens, 2.6 sec of HPU irradiation will screen weak bond conditions due to improper preparation of bonding surfaces; (2) for composite/composite specimens, 2.0 sec of HPU irradiation will disrupt weak bonds due to under-cured conditions; (3) for Al honeycomb core with composite skin structure, 3.5 sec of HPU irradiation will disrupt weak bonds due to bad adhesive or oils contamination of bonding surfaces; and (4) for Nomex honeycomb with Al skin structure, 1.3 sec of HPU irradiation will disrupt weak bonds due to bad adhesive.

  13. Damage Effects of Shelled Explosive Explosion in Concrete

    Directory of Open Access Journals (Sweden)

    Liu Yan

    2010-10-01

    Full Text Available The damage of concrete subjected to explosion loading is an important issue in defense engineering. The damage degree of concrete is related to many factors, such as the type of explosive charge, the depth of burial and the parameters of concrete. In this paper, three factors are considered for experiments of shelled explosives in concrete targets, which are the filling coefficient, length-to-diameter ratio and the depth of burial. The filling coefficient is from 0.1 to 1 by changing thickness of shell, and length-to-diameter ratio is from 2.5 to 10. The unconfined compressive strength of concrete target for test is 35MPa. The experimental results showed that the sizes of craters of concretes are varied as the filling coefficient, length-to-diameter ratio and the depth of burial. The optimal values of filling coefficient, length-to-diameter ratio and the depth of burial of shelled charges were obtained to get largest damage regions of concrete targets. This work provides a base for evaluating the damage of concrete and designing the penetrating warhead.Defence Science Journal, 2010, 60(6, pp.672-677, DOI:http://dx.doi.org/10.14429/dsj.60.434

  14. Reviving the Case for GDP-Indexed Bonds

    OpenAIRE

    Eduardo Borensztein; Paolo Mauro

    2002-01-01

    This paper seeks to revive the case for countries to self-insure against economic growth slowdowns by issuing GDP-indexed bonds. We simulate the effects of GDP-indexed bonds under different assumptions about fiscal policy reaction functions and their output effects and find that they could substantially reduce the likelihood that debt/GDP paths become explosive. The insurance premium would likely be small, because cross-country comovement of GDP growth rates is low and cross-country GDP growt...

  15. Detonation Mechanism in Double Vertical Explosive Welding of Stainless Steel/Steel

    Institute of Scientific and Technical Information of China (English)

    Chang-gen SHI; Yu WANG; Lin-sheng ZHAO; Hong-bao HOU; Yu-heng GE

    2015-01-01

    One-dimensional detonation model and two-dimensional P-M (Prandtl-Meyer) expanding model of double vertical ex-plosive welding were established. A one-dimensional formula of lfyer plate velocity was obtained and the bending angle curve rep-resenting lfying attitude of lfyer plate in double vertical was deduced as well. Compared with single parallel explosive welding, the double vertical explosive welding combines two cladding plates in one explosion. Due to closed charging structure, the inlfuence of rarefaction wave on the plate's surface in double vertical explosive welding is eliminated and explosion loading time and displace-ment are increased, resulting in the increase of lfyer velocity and energy utilization rate by 1.3 times to 1.6 times in different mass ratios. The analysis of microstructure in bonding zone of double vertical cladding plate under traditional charging shows that there is a clear over-melting near the interface, which is in line with the conclusion of detonation mechanism.

  16. Hazards of explosives dusts: Particle size effects

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-02-01

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

  17. Underwater explosions and cavitation phenomena

    International Nuclear Information System (INIS)

    Some aspects of underwater explosions and cavitation phenomena have been studied by using a thermodynamic equation of state for water and a one-dimensional Lagrangian hydrocode. The study showed that surface cavitation is caused by the main blast wave and a bubble pulse from rebound of a release wave moving toward the center of the exploding bubble. Gravity has little effect on the surface cavitation. In nuclear explosions the bubble is bounded by a two-phase region rather than a gas-water interface. The two-phase region cavitates as the bubble expands, changing the optical absorption coefficient by many orders of magnitude and significantly affecting the optical signature. In assessing cavitation damage, it is concluded that a water jet of unstable bubble collapse erodes solid walls. The study leads to suggestions for future research

  18. RANCHERO explosive pulsed power experiments

    CERN Document Server

    Goforth, J H; Armijo, E V; Atchison, W L; Bartos, Yu; Clark, D A; Day, R D; Deninger, W J; Faehl, R J; Fowler, C M; García, F P; García, O F; Herrera, D H; Herrera, T J; Keinigs, R K; King, J C; Lindemuth, I R; López, E; Martínez, E C; Martínez, D; McGuire, J A; Morgan, D; Oona, H; Oro, D M; Parker, J V; Randolph, R B; Reinovsky, R E; Rodríguez, G; Stokes, J L; Sena, F C; Tabaka, L J; Tasker, D G; Taylor, A J; Torres, D T; Anderson, H D; Broste, W B; Johnson, J B; Kirbie, H C

    1999-01-01

    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 HEPP system is a coaxial generator with a 304.8 mm diameter stator, and an initial armature diameter of 152 mm. The armature is expanded by a high explosive (HE) charge detonated simultaneously along its axis. The authors have reported a variety of experiments conducted with generator modules 43 cm long and have presented an initial design for hydrodynamic liner experiments. In this paper, they give a synopsis of their first system test, and a status report on the development of a generator module that is 1.4 m long. (6 refs).

  19. Waves from an underground explosion

    Science.gov (United States)

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

    1984-05-01

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

  20. Copper wire bonding

    CERN Document Server

    Chauhan, Preeti S; Zhong, ZhaoWei; Pecht, Michael G

    2014-01-01

    This critical volume provides an in-depth presentation of copper wire bonding technologies, processes and equipment, along with the economic benefits and risks.  Due to the increasing cost of materials used to make electronic components, the electronics industry has been rapidly moving from high cost gold to significantly lower cost copper as a wire bonding material.  However, copper wire bonding has several process and reliability concerns due to its material properties.  Copper Wire Bonding book lays out the challenges involved in replacing gold with copper as a wire bond material, and includes the bonding process changes—bond force, electric flame off, current and ultrasonic energy optimization, and bonding tools and equipment changes for first and second bond formation.  In addition, the bond–pad metallurgies and the use of bare and palladium-coated copper wires on aluminum are presented, and gold, nickel and palladium surface finishes are discussed.  The book also discusses best practices and re...

  1. Equilibrium CO bond lengths

    Science.gov (United States)

    Demaison, Jean; Császár, Attila G.

    2012-09-01

    Based on a sample of 38 molecules, 47 accurate equilibrium CO bond lengths have been collected and analyzed. These ultimate experimental (reEX), semiexperimental (reSE), and Born-Oppenheimer (reBO) equilibrium structures are compared to reBO estimates from two lower-level techniques of electronic structure theory, MP2(FC)/cc-pVQZ and B3LYP/6-311+G(3df,2pd). A linear relationship is found between the best equilibrium bond lengths and their MP2 or B3LYP estimates. These (and similar) linear relationships permit to estimate the CO bond length with an accuracy of 0.002 Å within the full range of 1.10-1.43 Å, corresponding to single, double, and triple CO bonds, for a large number of molecules. The variation of the CO bond length is qualitatively explained using the Atoms in Molecules method. In particular, a nice correlation is found between the CO bond length and the bond critical point density and it appears that the CO bond is at the same time covalent and ionic. Conditions which permit the computation of an accurate ab initio Born-Oppenheimer equilibrium structure are discussed. In particular, the core-core and core-valence correlation is investigated and it is shown to roughly increase with the bond length.

  2. The Bond Market's q

    OpenAIRE

    Thomas Philippon

    2006-01-01

    I propose an implementation of the q-theory of investment using bond prices instead of equity prices. Credit risk makes corporate bond prices sensitive to future asset values, and q can be inferred from bond prices. The bond market's q performs much better than the usual measure in standard investment equations. With aggregate data, the fit is three times better, cash flows are driven out and the implied adjustment costs are reduced by more than an order of magnitude. The new measure also imp...

  3. EXPLOSION RISK ASSESSMENTS FOR FACILITIES

    Directory of Open Access Journals (Sweden)

    Martin KULICH

    2015-12-01

    Full Text Available In the first part of the article we discuss the possibilities and analytical tools that can deal with the classification of space into zones with danger of explosion for devices with the presence of compressed flammable gases. Then we continue with specifications of possibilities for practical utilization linked to variables such as ventilation degree, hypothetical volume etc., including the examples. At the end we also give a brief overview of software for modelling gas leak, including examples of an outcome.

  4. Explosive Formulation Code Naming SOP

    Energy Technology Data Exchange (ETDEWEB)

    Martz, H. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-09-19

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

  5. Causes of the Cambrian Explosion.

    OpenAIRE

    Smith, M P; Harper, D.A.T.

    2013-01-01

    In the last decade, at least thirty individual hypotheses have been invoked to explain the Cambrian Explosion, ranging from starbursts in the Milky Way to intrinsic genomic reorganization and developmental patterning. It has been noted (1) that recent hypotheses fall into three categories: a) developmental/genetic, b) ecologic and c) abiotic environmental, with geochemical hypotheses forming an abundant and distinctive subset of the last. With a few notable exceptions, a significant majority ...

  6. Nuclear Explosions 1945-1998

    International Nuclear Information System (INIS)

    The main part of this report is a list of nuclear explosions conducted by the United States, the Soviet Union, the United Kingdom, France, China, India and Pakistan in 1945-98. The list includes all known nuclear test explosions and is compiled from a variety of sources including officially published information from the USA, Russia and France. The details given for each explosion (date, origin time, location, yield, type, etc.) are often compiled from more than one source because the individual sources do not give complete information. The report includes a short background to nuclear testing and provides brief information on the Comprehensive Nuclear-Test-Ban Treaty and the verification regime now being established to verify compliance with the treaty. It also summarizes nuclear testing country by country. The list should be used with some caution because its compilation from a variety of sources means that some of the data could be incorrect. This report is the result of cooperation between the Defence Research Establishment (FOA) and the Stockholm International Peace Research Institute (SIPRI)

  7. Nuclear Explosions 1945-1998

    Energy Technology Data Exchange (ETDEWEB)

    Bergkvist, Nils-Olov; Ferm, Ragnhild

    2000-07-01

    The main part of this report is a list of nuclear explosions conducted by the United States, the Soviet Union, the United Kingdom, France, China, India and Pakistan in 1945-98. The list includes all known nuclear test explosions and is compiled from a variety of sources including officially published information from the USA, Russia and France. The details given for each explosion (date, origin time, location, yield, type, etc.) are often compiled from more than one source because the individual sources do not give complete information. The report includes a short background to nuclear testing and provides brief information on the Comprehensive Nuclear-Test-Ban Treaty and the verification regime now being established to verify compliance with the treaty. It also summarizes nuclear testing country by country. The list should be used with some caution because its compilation from a variety of sources means that some of the data could be incorrect. This report is the result of cooperation between the Defence Research Establishment (FOA) and the Stockholm International Peace Research Institute (SIPRI)

  8. Thermodynamic States in Explosion Fields

    Energy Technology Data Exchange (ETDEWEB)

    Kuhl, A L

    2010-03-12

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

  9. Determination of Nanogram Microparticles from Explosives after Real Open-Air Explosions by Confocal Raman Microscopy.

    Science.gov (United States)

    Zapata, Félix; García-Ruiz, Carmen

    2016-07-01

    Explosives are increasingly being used for terrorist attacks to cause devastating explosions. The detection of their postblast residues after an explosion is a high challenge, which has been barely investigated, particularly using spectroscopic techniques. In this research, a novel methodology using confocal Raman microscopy has been developed for the analysis of postblast residues from 10 open-air explosions caused by 10 different explosives (TNT, RDX, PETN, TATP, HMTD, dynamite, black powder, ANFO, chloratite, and ammonal) commonly used in improvised explosive devices. The methodology for the determination of postblast particles from explosives consisted of examining the samples surfaces with both the naked eye, first, and microscopically (10× and 50×), immediately afterward; and finally, analyzing the selected residues by confocal Raman spectroscopy in order to identify the postblast particles from explosives. Interestingly, confocal Raman microscopy has demonstrated to be highly suitable to rapidly, selectively, and noninvasively analyze postblast microscopic particles from explosives up to the nanogram range.

  10. Comparison of Gold Bonding with Mercury Bonding

    NARCIS (Netherlands)

    Kraka, Elfi; Filatov, Michael; Cremer, Dieter

    2009-01-01

    Nine AuX molecules (X = H, O, S, Se, Te, F, Cl, Br, I), their isoelectronic HgX(+) analogues, and the corresponding neutral HgX diatomics have been investigated using NESC (Normalized Elimination of the Small Component) and B3LYP theory to determine relativistic effects for bond dissociation energie

  11. Data base of chemical explosions in Kazakhstan

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-01

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

  12. Coupled valence bond theory

    NARCIS (Netherlands)

    Havenith, R.W.A.

    2005-01-01

    In this Letter, the formulation and implementation of a parallel response property code for non-orthogonal, valence bond wave-functions are described. Test calculations on benzene and cyclobutadiene show that the polarisability and magnetisability tensors obtained using valence bond theory are compa

  13. Bonded labour in Pakistan

    OpenAIRE

    Ercelawn, Aly; Nauman, Muhammad

    2001-01-01

    Examines the continuing prevalence of debt bondage in the 1990s despite the introduction of national legislation banning the practice. Makes recommendations to the Government and the international community for actions to be taken to eliminate bonded labour and provide rehabilitation for freed workers. Includes texts of Land Reforms Regulations, 1972, the Sindh Tenancy Act, 1950 and the Bonded Labour System (Abolition) Act, 1992.

  14. Hydrogen bonding in polyanilines

    Energy Technology Data Exchange (ETDEWEB)

    Bahceci, S. (Department of Chemistry, Middle East Technical University, Ankara 06531 (Turkey)); Toppare, L. (Department of Chemistry, Middle East Technical University, Ankara 06531 (Turkey)); Yurtsever, E. (Department of Chemistry, Middle East Technical University, Ankara 06531 (Turkey))

    1994-11-29

    Hydrogen bonding between poly(bisphenol A carbonate) (PC) and polyaniline (PAn) is analyzed using semi-empirical quantum methodology. Fully optimized AM1 molecular orbital calculations are reported for various aniline structures (monomer, dimer and trimer), the monomer of the PC and the hydrogen-bonded model of PAn-PC oligomer. ((orig.))

  15. The dissociative bond.

    Science.gov (United States)

    Gordon, Nirit

    2013-01-01

    Dissociation leaves a psychic void and a lingering sense of psychic absence. How do 2 people bond while they are both suffering from dissociation? The author explores the notion of a dissociative bond that occurs in the aftermath of trauma--a bond that holds at its core an understanding and shared detachment from the self. Such a bond is confined to unspoken terms that are established in the relational unconscious. The author proposes understanding the dissociative bond as a transitional space that may not lead to full integration of dissociated knowledge yet offers some healing. This is exemplified by R. Prince's (2009) clinical case study. A relational perspective is adopted, focusing on the intersubjective aspects of a dyadic relationship. In the dissociative bond, recognition of the need to experience mutual dissociation can accommodate a psychic state that yearns for relationship when the psyche cannot fully confront past wounds. Such a bond speaks to the need to reestablish a sense of human relatedness and connection when both parties in the relationship suffer from disconnection. This bond is bound to a silence that becomes both a means of protection against the horror of traumatic memory and a way to convey unspoken gestures toward the other.

  16. The samurai bond market

    OpenAIRE

    Frank Packer; Elizabeth Reynolds

    1997-01-01

    Issuance in the samurai bond market has more than tripled over the past several years. Some observers have attributed this growth to a systematic underestimation of credit risk in the market. A detailed review of credit quality, ratings differences, and initial issue pricing in the samurai bond market, however, turns up little evidence to support this concern.

  17. Wood Bond Testing

    Science.gov (United States)

    1989-01-01

    A joint development program between Hartford Steam Boiler Inspection Technologies and The Weyerhaeuser Company resulted in an internal bond analyzer (IBA), a device which combines ultrasonics with acoustic emission testing techniques. It is actually a spinoff from a spinoff, stemming from a NASA Lewis invented acousto-ultrasonic technique that became a system for testing bond strength of composite materials. Hartford's parent company, Acoustic Emission Technology Corporation (AET) refined and commercialized the technology. The IBA builds on the original system and incorporates on-line process control systems. The IBA determines bond strength by measuring changes in pulsar ultrasonic waves injected into a board. Analysis of the wave determines the average internal bond strength for the panel. Results are displayed immediately. Using the system, a mill operator can adjust resin/wood proportion, reduce setup time and waste, produce internal bonds of a consistent quality and automatically mark deficient products.

  18. Water's Hydrogen Bond Strength

    CERN Document Server

    Chaplin, Martin

    2007-01-01

    Water is necessary both for the evolution of life and its continuance. It possesses particular properties that cannot be found in other materials and that are required for life-giving processes. These properties are brought about by the hydrogen bonded environment particularly evident in liquid water. Each liquid water molecule is involved in about four hydrogen bonds with strengths considerably less than covalent bonds but considerably greater than the natural thermal energy. These hydrogen bonds are roughly tetrahedrally arranged such that when strongly formed the local clustering expands, decreasing the density. Such low density structuring naturally occurs at low and supercooled temperatures and gives rise to many physical and chemical properties that evidence the particular uniqueness of liquid water. If aqueous hydrogen bonds were actually somewhat stronger then water would behave similar to a glass, whereas if they were weaker then water would be a gas and only exist as a liquid at sub-zero temperature...

  19. I-RDX及其PBX老化研究进展%Review on Ageing of I-RDX and I-RDX Based PBX

    Institute of Scientific and Technical Information of China (English)

    高晓敏; 黄明

    2010-01-01

    总结了降感黑索今(I-RDX)及其高聚物黏结炸药(PBX)老化研究成果,从 RDX晶体特性及其评价方法、I-RDX及其PBX老化前后的晶体特性、冲击波感度特性方面进行了综述,认为I-RDX晶体中不含奥克托今(HMX)或含有微量HMX、或机械混入少量HMX时,材料老化后的冲击波感度特性没有明显变化,最后对I-RDX晶体中HMX的影响机理进行了讨论.

  20. Thermal explosion in oscillating ambient conditions

    Science.gov (United States)

    Novozhilov, Vasily

    2016-07-01

    Thermal explosion problem for a medium with oscillating ambient temperature at its boundaries is considered. This is a new problem in thermal explosion theory, not previously considered in a distributed system formulation, but important for combustion and fire science. It describes autoignition of wide range of fires (such as but not limited to piles of biosolids and other organic matter; storages of munitions, explosives, propellants) subjected to temperature variations, such as seasonal or day/night variation. The problem is considered in formulation adopted in classical studies of thermal explosion. Critical conditions are determined by frequency and amplitude of ambient temperature oscillations, as well as by a number of other parameters. Effects of all the parameters on critical conditions are quantified. Results are presented for the case of planar symmetry. Development of thermal explosion in time is also considered, and a new type of unsteady thermal explosion development is discovered where thermal runaway occurs after several periods of temperature oscillations within the medium.

  1. Explosives Detection: Exploitation of the Physical Signatures

    Science.gov (United States)

    Atkinson, David

    2010-10-01

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

  2. APPLICATION OF EXPLOSIVE ENERGY IN METALWORKING

    Directory of Open Access Journals (Sweden)

    Vječislav Bohanek

    2013-07-01

    Full Text Available When an explosive charge is detonate, considerable amount of energy in a very short period of time is released. Energy, released in this way, is used for performing various kinds of useful work. Most explosives are consumed to obtain mineral raw materials in the mining industry and for various excavations in the construction industry. One of the specific areas of application explosive energy is an area of explosive metalworking. Using energy of explosive metal is welded, formed, cuts, harden etc. This paper presents an overview of the existing explosive metalworking methods. Methods are explained and comparative advantages in comparison to conventional metalworking methods are given (the paper is published in Croatian.

  3. New Dark Matter Detector using Nanoscale Explosives

    OpenAIRE

    Lopez, Alejandro; Drukier, Andrzej; Freese, Katherine; Kurdak, Cagliyan; Tarle, Gregory

    2014-01-01

    We present nanoscale explosives as a novel type of dark matter detector and study the ignition properties. When a Weakly Interacting Massive Particle WIMP from the Galactic Halo elastically scatters off of a nucleus in the detector, the small amount of energy deposited can trigger an explosion. For specificity, this paper focuses on a type of two-component explosive known as a nanothermite, consisting of a metal and an oxide in close proximity. When the two components interact they undergo a ...

  4. Analysis of TROI-13 Steam Explosion Experiment

    OpenAIRE

    Mitja Uršič; Matjaž Leskovar

    2008-01-01

    The prediction of steam explosion inducing loads in nuclear power plants must be based on results of experimental research programmes and on simulations using validated fuel-coolant interaction codes. In this work, the TROI-13 steam explosion experiment was analysed with the fuel-coolant interaction MC3D computer code. The TROI-13 experiment is one of several experiments performed in the TROI research program and resulted in a spontaneous steam explosion using corium melt. First, the TROI-13 ...

  5. Is a Cambrian Explosion Coming for Robotics?

    OpenAIRE

    Gill A. Pratt

    2015-01-01

    About half a billion years ago, life on earth experienced a short period of very rapid diversification called the "Cambrian Explosion." Many theories have been proposed for the cause of the Cambrian Explosion, one of the most provocative being the evolution of vision, allowing animals to dramatically increase their ability to hunt and find mates. Today, technological developments on several fronts are fomenting a similar explosion in the diversification and applicability of robotics. Many of ...

  6. Stellar Explosions: Hydrodynamics and Nucleosynthesis

    Science.gov (United States)

    José, Jordi

    2015-12-01

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

  7. The gas dynamics of explosions

    CERN Document Server

    Lee,\tJohn H S

    2016-01-01

    Explosions, and the non-steady shock propagation associated with them, continue to interest researchers working in different fields of physics and engineering (such as astrophysics and fusion). Based on the author's course in shock dynamics, this book describes the various analytical methods developed to determine non-steady shock propagation. These methods offer a simple alternative to the direct numerical integration of the Euler equations and offer a better insight into the physics of the problem. Professor Lee presents the subject systematically and in a style that is accessible to graduate students and researchers working in shock dynamics, combustion, high-speed aerodynamics, propulsion and related topics.

  8. Explosive demolition of activated concrete

    International Nuclear Information System (INIS)

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

  9. Detonation Propagation Characteristics of Superposition Explosive Materials

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In order to investigate detonation propagation characteristics of different charge patterns,the detonation velocities of superposition strip-shaped charges made up of a detonating cord and explosives were measured by a detonation velocity measuring instrument under conditions of different ignition.The experimental results and theoretical analysis show that the maximum detonation propagation velocity depends on the explosive materials with the maximum velocity among all the explosive materials.Using detonating cord in a superposition charge can shorten detonation propagation time and improve the efficiency of explosive energy.The measurement method of detonation propagation velocity and experimental results are presented and investigated.

  10. High Explosives Research and Development (HERD) Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The purpose is to provide high explosive formulation, chemical analysis, safety and performance testing, processing, X-ray, quality control and loading support for...

  11. Analysis of TROI-13 Steam Explosion Experiment

    Directory of Open Access Journals (Sweden)

    Mitja Uršič

    2008-01-01

    Full Text Available The prediction of steam explosion inducing loads in nuclear power plants must be based on results of experimental research programmes and on simulations using validated fuel-coolant interaction codes. In this work, the TROI-13 steam explosion experiment was analysed with the fuel-coolant interaction MC3D computer code. The TROI-13 experiment is one of several experiments performed in the TROI research program and resulted in a spontaneous steam explosion using corium melt. First, the TROI-13 premixing simulations were performed to determine the initial conditions for the steam explosion simulations and to evaluate the melt droplets hydrodynamic fragmentation model. Next, a number of steam explosion simulations were performed, varying the steam explosion triggering position and the melt droplets mass participating in the steam explosion. The simulation results revealed that there is an important influence of the participating melt droplets mass on the calculated pressure loads, whereas the influence of the steam explosion triggering position on the steam explosion development was less expressive.

  12. Explosive Field Visualization Based on Image Fusion

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wen-yao; JIANG Ling-shuang

    2009-01-01

    m the composite sequence. Experimental results show that the new images integrate the advantages of sources, effectively improve the visualization, and disclose more information about explosive field.

  13. Transversely Compressed Bonded Joints

    DEFF Research Database (Denmark)

    Hansen, Christian Skodborg; Schmidt, Jacob Wittrup; Stang, Henrik

    2012-01-01

    The load capacity of bonded joints can be increased if transverse pressure is applied at the interface. The transverse pressure is assumed to introduce a Coulomb-friction contribution to the cohesive law for the interface. Response and load capacity for a bonded single-lap joint was derived using...... non-linear fracture mechanics. The results indicated a good correlation between theory and tests. Furthermore, the model is suggested as theoretical base for determining load capacity of bonded anchorages with transverse pressure, in externally reinforced concrete structures....

  14. 27 CFR 555.181 - Reporting of plastic explosives.

    Science.gov (United States)

    2010-04-01

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

  15. 30 CFR 75.1310 - Explosives and blasting equipment.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Explosives and blasting equipment. 75.1310... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1310 Explosives and blasting equipment. (a) Only permissible explosives, approved sheathed explosive units,...

  16. Chernobyl: Anatomy of the explosion

    International Nuclear Information System (INIS)

    On Friday, 26 April 1986, it was planned to shut down the fourth unit of the Chernobyl Atomic Power Station, U.S.S.R., for periodic maintenance. The procedure supplied the opportunity to perform a further experiment; operation of the turbine in free rotation regime, which occurs when the steam is cut down while the turbine is still running. It so happened that carrying out this experiment turned out to be the worst accident in the history of nuclear power industry. The first part of the article proceeds to a second by second detailed analysis of the causes of the catastrophe. The analysis uses official data and reports. The author covers the sequence of events, which led up to two explosions in the second hour of that tragic morning. In the second part of the article, the author provides hints and suggestions, so that 'the tragedy of Chernobyl does not become a useless lesson'. With regard to what, so far, has been published, the novelty of the article may be a diagram showing the excessive changes that affected the main parameters (power, water flow through circulating pumps, steam pressure in separators, and length of the immersed part of control rods) in the fourth unit during the last seconds before the explosion. If may be noteworthy to mention that the curves supplied here are based on data stored in the computer 'SCALA'. 2 figs

  17. Cosmic Explosions in Three Dimensions

    Science.gov (United States)

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

    2004-12-01

    Introduction: 3-D Explosions: a meditation on rotation (and magnetic fields) J. C. Wheeler; Part I. Supernovae: Observations Today: 1. Supernova explosions: lessons from spectropolarimetry L. Wang; 2. Spectropolarimetric observations of Supernovae A. Filippenko and D. C. Leonard; 3. Observed and physical properties of type II plateau supernovae M. Hamuy; 4. SN1997B and the different types of Type Ic Supernovae A. Clocchiatti, B. Leibundgut, J. Spyromilio, S. Benetti, E. Cappelaro, M. Turatto and M. Phillips; 5. Near-infrared spectroscopy of stripped-envelope Supernovae C. L. Gerardy, R. A. Fesen, G. H. Marion, P. Hoeflich and J. C. Wheeler; 6. Morphology of Supernovae remnants R. Fesen; 7. The evolution of Supernova remnants in the winds of massive stars V. Dwarkadas; 8. Types for the galactic Supernovae B. E. Schaefer; Part II. Theory of Thermonuclear Supernovae: 9. Semi-steady burning evolutionary sequences for CAL 83 and CAL 87: supersoft X-ray binaries are Supernovae Ia progenitors S. Starrfield, F. X. Timmes, W. R. Hix, E. M. Sion, W. M. Sparks and S. Dwyer; 10. Type Ia Supernovae progenitors: effects of the spin-up of the white dwarfs S.-C. Yoon and N. Langer; 11. Terrestrial combustion: feedback to the stars E. S. Oran; 12. Non-spherical delayed detonations E. Livne; 13. Numerical simulations of Type Ia Supernovae: deflagrations and detonations V. N. Gamezo, A. M. Khokhlov and E. S. Oran; 14. Type Ia Supernovae: spectroscopic surprises D. Branch; 15. Aspherity effects in Supernovae P. Hoeflich, C. Gerardy and R. Quimby; 16. Broad light curve SneIa: asphericity or something else? A. Howell and P. Nugent; 17. Synthetic spectrum methods for 3-D SN models R. Thomas; 18. A hole in Ia' spectroscopic and polarimetric signatures of SN Ia asymmetry due to a companion star D. Kasen; 19. Hunting for the signatures of 3-D explosions with 1-D synthetic spectra E. Lentz, E. Baron and P. H. Hauschildt; 20. On the variation of the peak luminosity of Type Ia J. W. Truran, E

  18. Low Frequency Electromagnetic Pulse and Explosions

    Energy Technology Data Exchange (ETDEWEB)

    Sweeney, J J

    2011-02-01

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

  19. Close-in airblast from underground explosions

    International Nuclear Information System (INIS)

    Air overpressures as a function of time have been measured from surface zero to about 170 ft/lb1/3 along the ground from nuclear and chemical explosions. Charge depths varied from the surface to depths below which explosion gases are contained. A ground-shock-induced air pressure pulse is clearly distinguishable from the pulse caused by venting gases. Measured peak overpressures show reasonable agreement with the theoretical treatment by Monta. In a given medium the suppression of blast with explosion burial depth is a function of the relative distance at which the blast is observed. Rates of suppression of peak overpressure with charge burial are different for the two pulses. Rates are determined for each pulse over the range of distances at which measurements have been made of air overpressure from chemical explosions in several media. Nuclear data are available from too few shots for similar dependence on burial depth and distance to be developed, but it is clear that the gas venting peak overpressure from nuclear explosions is much more dependent on medium than that from chemical explosions. For above-ground explosions, experiment has shown that airblast from a I-kiloton nuclear explosion is equal to that from a 0.5-kiloton TNT explosion. Data on ground-shock-induced airblast is now sufficient to show that a similar relationship may exist for buried explosions. Because of medium dependence of the gas venting pulse from nuclear explosions, data from additional nuclear events will be required before a chemical/nuclear airblast equivalence can be determined for the gas-venting pulse. (author)

  20. Handbook of wafer bonding

    CERN Document Server

    Ramm, Peter; Taklo, Maaike M V

    2011-01-01

    Written by an author and editor team from microsystems companies and industry-near research organizations, this handbook and reference presents dependable, first-hand information on bonding technologies.In the first part, researchers from companies and institutions around the world discuss the most reliable and reproducible technologies for the production of bonded wafers. The second part is devoted to current and emerging applications, including microresonators, biosensors and precise measuring devices.

  1. Summary of European directives for explosion safety

    NARCIS (Netherlands)

    Versloot, N.H.A.; Klein, A.J.J.; Maaijer, M. de

    2008-01-01

    On July 1, 2003 a transitional period has ended and two European directives became fully active: • Directive 1999/92/EC • Directive 94/9/EC These directives have an impact on companies with an explosion hazard (gas, vapor, mist, or dust explosions) and on manufacturers of equipment intended to be us

  2. Splitting PMMA with Mini Cutting Explosives

    Institute of Scientific and Technical Information of China (English)

    LI Zhiqiang; LIU Xiaomin; XIAO Yin; ZHAO Yonggang; ZHAO Longmao

    2006-01-01

    In order to improve the present aviation ejection escape system,the application of explosion cutting technique to aviation escape system is proposed to weaken the strength of canopy before ejecting it.A series of mini cutting explosives are designed to investigate the process of splitting PMMA plate.The phenomenon of spallation in PMMA is observed.The effects of different parameters of mini cutting explosives on the cutting depth are obtained.Consequently the appropriate material of half-circular metal covers,explosive types and the ranges of charge quantities are determined.On the other hand,the cutting process of aviation PMMA plate by mini cutting explosives is simulated by means of nonlinear dynamic analysis code LS-DYNA.In finite element analysis,Arbitrary Lagrangian Euler (ALE) algorithm is used to depict the fluid property of high energy explosives.Continuous damage material model is used to simulate the complicate dynamic damage behavior of PMMA due to explosion shock waves.Only sliding contact option is defined to fulfill the fluid-structure interaction between explosives and PMMA plate by distributed parameter methods.Phenomenon of spallation observed in the experiment is presented in the simulation.The relationship between the penetration depth of PMMA plate and charge linear density obtained by numerical simulation agrees well with experimental result.

  3. Fire and explosion hazards of oil shale

    Energy Technology Data Exchange (ETDEWEB)

    1989-01-01

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

  4. 76 FR 8923 - Explosive Siting Requirements

    Science.gov (United States)

    2011-02-16

    ... ``explosive hazard facility'' as a facility at a launch site where solid propellant, liquid propellant, or... would no longer refer to the solid explosives governed by this section as solid propellants because, technically, the provision applies to more than just solid propellants. Currently, Sec. 420.65 states that...

  5. Glass produced by underground nuclear explosions

    International Nuclear Information System (INIS)

    Detonation of an underground nuclear explosive produces a strong shock wave which propagates spherically outward, vaporizing the explosive and nearby rock and melting, the surrounding rock. The vaporized material expands adiabatically, forming a cavity. As the energy is dissipated during the cavity formation process, the explosive and rock debris condense and mix with the melted rock. The melt flows to the bottom of the cavity where it is quenched by fractured rock fragments falling from above as the cavity collapses. Measurements indicate that about 740 tonnes of rock and/or soil are melted for every kiloton (1012 calories) of explosive energy, or about 25% of the explosive energy goes to melting rock. The resulting glass composition reflects the composition of the unaltered rock with explosive debris. The appearance ranges from white pumice to dense, dark lava. The bulk composition and color vary with the amount of explosive iron incorporated into the glass. The refractory explosion products are mixed with the solidified melt, although the degree of mixing is variable. Electron microprobe studies of glasses produced by Rainier in welded tuff have produced the following results: glasses are dehydrated relative to the host media, glasses are extremely heterogeneous on a 20 μm scale, a ubiquitous feature is the presence of dark marble-cake regions in the glass, which were locally enriched in iron and may be related to the debris, optically amorphous regions provide evidence of shock melting, only limited major element redistribution and homogenization occur within the cavity

  6. 49 CFR 173.59 - Description of terms for explosives.

    Science.gov (United States)

    2010-10-01

    .... Substances consisting of a deflagrating liquid explosive, used for propulsion. Propellant, solid. Substances consisting of a deflagrating solid explosive, used for propulsion. Propellants. Deflagrating explosives used... equipment quickly. Rocket motors. Articles consisting of a solid, liquid, or hypergolic propellant...

  7. Morphomechanical Innovation Drives Explosive Seed Dispersal.

    Science.gov (United States)

    Hofhuis, Hugo; Moulton, Derek; Lessinnes, Thomas; Routier-Kierzkowska, Anne-Lise; Bomphrey, Richard J; Mosca, Gabriella; Reinhardt, Hagen; Sarchet, Penny; Gan, Xiangchao; Tsiantis, Miltos; Ventikos, Yiannis; Walker, Simon; Goriely, Alain; Smith, Richard; Hay, Angela

    2016-06-30

    How mechanical and biological processes are coordinated across cells, tissues, and organs to produce complex traits is a key question in biology. Cardamine hirsuta, a relative of Arabidopsis thaliana, uses an explosive mechanism to disperse its seeds. We show that this trait evolved through morphomechanical innovations at different spatial scales. At the organ scale, tension within the fruit wall generates the elastic energy required for explosion. This tension is produced by differential contraction of fruit wall tissues through an active mechanism involving turgor pressure, cell geometry, and wall properties of the epidermis. Explosive release of this tension is controlled at the cellular scale by asymmetric lignin deposition within endocarp b cells-a striking pattern that is strictly associated with explosive pod shatter across the Brassicaceae plant family. By bridging these different scales, we present an integrated mechanism for explosive seed dispersal that links evolutionary novelty with complex trait innovation. VIDEO ABSTRACT.

  8. Hydrodynamics of Explosion Experiments and Models

    CERN Document Server

    Kedrinskii, Valery K

    2005-01-01

    Hydronamics of Explosion presents the research results for the problems of underwater explosions and contains a detailed analysis of the structure and the parameters of the wave fields generated by explosions of cord and spiral charges, a description of the formation mechanisms for a wide range of cumulative flows at underwater explosions near the free surface, and the relevant mathematical models. Shock-wave transformation in bubbly liquids, shock-wave amplification due to collision and focusing, and the formation of bubble detonation waves in reactive bubbly liquids are studied in detail. Particular emphasis is placed on the investigation of wave processes in cavitating liquids, which incorporates the concepts of the strength of real liquids containing natural microinhomogeneities, the relaxation of tensile stress, and the cavitation fracture of a liquid as the inversion of its two-phase state under impulsive (explosive) loading. The problems are classed among essentially nonlinear processes that occur unde...

  9. Ionospheric effects of supernova explosions

    Science.gov (United States)

    Edwards, P. J.

    Possible ionospheric effects of supernova explosions are considered, with special attention given to those of SN 1987a. Results are presented on the calculations of anticipated X-ray/UV flare parameters, including the shock temperature, the minimum flare duration, the average photon energy, and the shock-front travel time for a range of stellar radii bracketing SK 202-69, which was identified by White Malin (1987) as the progenitor star for SN 1987a. It is shown that the characteristics of the X-ray/UV flare are strongly influenced by the radius of the shock wave breakout, so that the flare from SN 1987a can be anticipated to have characteristics intermediate between those attributed to compact stars and stars with extended envelopes.

  10. Mass extinctions and supernova explosions

    CERN Document Server

    Korschinek, Gunther

    2016-01-01

    A nearby supernova (SN) explosion could have negatively influenced life on Earth, maybe even been responsible for mass extinctions. Mass extinction poses a significant extinction of numerous species on Earth, as recorded in the paleontologic, paleoclimatic, and geological record of our planet. Depending on the distance between the Sun and the SN, different types of threats have to be considered, such as ozone depletion on Earth, causing increased exposure to the Sun's ultraviolet radiation, or the direct exposure of lethal x-rays. Another indirect effect is cloud formation, induced by cosmic rays in the atmosphere which result in a drop in the Earth's temperature, causing major glaciations of the Earth. The discovery of highly intensive gamma ray bursts (GRBs), which could be connected to SNe, initiated further discussions on possible life-threatening events in Earth's history. The probability that GRBs hit the Earth is very low. Nevertheless, a past interaction of Earth with GRBs and/or SNe cannot be exclude...

  11. 27 CFR 555.109 - Identification of explosive materials.

    Science.gov (United States)

    2010-04-01

    ... Business or Operations § 555.109 Identification of explosive materials. (a) General. Explosive materials... in the English language, using Roman letters and Arabic numerals. (3) Licensed manufacturers...

  12. Romanian government bond market

    Directory of Open Access Journals (Sweden)

    Cornelia POP

    2012-12-01

    Full Text Available The present paper aims to present the level of development reached by Romanian government bond market segment, as part of the country financial market. The analysis will be descriptive (the data series available for Romania are short, based on the secondary data offered by the official bodies involved in the process of issuing and trading the Romanian government bonds (Romanian Ministry of Public Finance, Romanian National Bank and Bucharest Stock Exchange, and also on secondary data provided by the Federation of European Stock Exchanges.To enhance the market credibility as a benchmark, a various combination of measures is necessary; among these measures are mentioned: the extension of the yield curve; the issuance calendars in order to improve transparency; increasing the disclosure of information on public debt issuance and statistics; holding regular meetings with dealers, institutional investors and rating agencies; introducing a system of primary dealers; establishing a repurchase (repo market in the government bond market. These measures will be discussed based on the evolution presented inside the paper.The paper conclude with the fact that, until now, the Romanian government bond market did not provide a benchmark for the domestic financial market and that further efforts are needed in order to increase the government bond market transparency and liquidity.

  13. An Environmentally Friendly Baratol Replacement for Plane Wave Generator Applications

    Science.gov (United States)

    Chavez, David E.; Harry, Herbert H.; Olinger, Barton W.

    2014-04-01

    The development of low adjustable detonation velocity plastic bonded explosive (PBX) formulations is described. The PBX consists of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), zinc oxide, and Viton A as the binder. We prepared several formulations and determined a range of sensitivity values with respect to impact, spark, friction, and thermal stability for these formulations. Furthermore, we experimentally determined the detonation velocity of each formulation and discovered that a detonation velocity near 5 km/s is attainable using 30 wt% HMX, 60 wt% zinc oxide, and 5 wt% Viton A.

  14. Development of ab initio techniques critical for future science-based explosives R&D.

    Energy Technology Data Exchange (ETDEWEB)

    Wixom, Ryan R.; Mattsson, Ann Elisabet

    2013-10-01

    Density Functional Theory (DFT) has emerged as an indispensable tool in materials research, since it can accurately predict properties of a wide variety of materials at both equilibrium and extreme conditions. However, for organic molecular crystal explosives, successful application of DFT has largely failed due to the inability of current exchange-correlation functionals to correctly describe intermolecular van der Waals (vdWs) forces. Despite this, we have discovered that even with no treatment of vdWs bonding, the AM05 functional and DFT based molecular dynamics (MD) could be used to study the properties of molecular crystals under compression. We have used DFT-MD to predict the unreacted Hugoniots for PETN and HNS and validated the results by comparison with crystalline and porous experimental data. Since we are also interested in applying DFT methods to study the equilibrium volume properties of explosives, we studied the nature of the vdWs bonding in pursuit of creating a new DFT functional capable of accurately describing equilibrium bonding of molecular crystals. In this report we discuss our results for computing shock Hugoniots of molecular crystals and also what was learned about the nature of bonding in these materials.

  15. Insulation bonding test system

    Science.gov (United States)

    Beggs, J. M.; Johnston, G. D.; Coleman, A. D.; Portwood, J. N.; Saunders, J. M.; Redmon, J. W.; Porter, A. C. (Inventor)

    1984-01-01

    A method and a system for testing the bonding of foam insulation attached to metal is described. The system involves the use of an impacter which has a calibrated load cell mounted on a plunger and a hammer head mounted on the end of the plunger. When the impacter strikes the insulation at a point to be tested, the load cell measures the force of the impact and the precise time interval during which the hammer head is in contact with the insulation. This information is transmitted as an electrical signal to a load cell amplifier where the signal is conditioned and then transmitted to a fast Fourier transform (FFT) analyzer. The FFT analyzer produces energy spectral density curves which are displayed on a video screen. The termination frequency of the energy spectral density curve may be compared with a predetermined empirical scale to determine whether a igh quality bond, good bond, or debond is present at the point of impact.

  16. Particle bonding, annealing response, and mechanical properties of dynamically consolidated type 304 stainless steel powders

    Science.gov (United States)

    Wright, R. N.; Korth, G. E.; Flinn, J. E.

    1989-11-01

    The nature of interparticle bonding in explosively consolidated, centrifugally atomized (CA), and vacuum gas-atomized (VGA) Type 304 stainless steel powders has been examined. Stress waves with sufficient amplitude to produce full density do not necessarily produce metallurgical bonds between particles; the local strain and strain rate are found to determine the degree of local heating and, in turn, the degree of particle fusion. Particle interaction is found to be limited to nearest neighbors. The as-consolidated CA material has approximately twice the ultimate tensile strength of mill-annealed wrought Type 304 stainless steel. Consolidated CA powder has a higher defect density than VGA powder consolidated under the same conditions; however, the VGA material recrystallizes at a lower temperature due to a lower concentration of carbides. Annealing explosively consolidated material produced from either powder results in sintering, improved particle bonding, and greater ductility.

  17. The Illiquidity of Corporate Bonds

    OpenAIRE

    Bao, Jack; Pan, Jun; Wang, Jiang

    2011-01-01

    This paper examines the illiquidity of corporate bonds and its asset-pricing implications. Using transactions data from 2003 to 2009, we show that the illiquidity in corporate bonds is substantial, significantly greater than what can be explained by bid–ask spreads. We establish a strong link between bond illiquidity and bond prices. In aggregate, changes in market-level illiquidity explain a substantial part of the time variation in yield spreads of high-rated (AAA through A) bonds, overshad...

  18. Fast Chromatographic Method for Explosive Profiling

    Directory of Open Access Journals (Sweden)

    Pierre-Hugues Stefanuto

    2015-05-01

    Full Text Available Security control is becoming a major global issue in strategic locations, such as airports, official buildings, and transit stations. The agencies responsible for public security need powerful and sensitive tools to detect warfare agents and explosives. Volatile signature detection is one of the fastest and easiest ways to achieve this task. However, explosive chemicals have low volatility making their detection challenging. In this research, we developed and evaluated fast chromatographic methods to improve the characterization of volatile signatures from explosives samples. The headspace of explosives was sampled with solid phase micro-extraction fiber (SPME. Following this step, classical gas chromatography (GC and comprehensive two-dimensional GC (GC×GC were used for analysis. A fast GC approach allows the elution temperature of each analyte to be decreased, resulting in decreased thermal degradation of sensitive compounds (e.g., nitro explosives. Using fast GC×GC, the limit of detection is further decreased based on the cryo-focusing effect of the modulator. Sampling of explosives and chromatographic separation were optimized, and the methods then applied to commercial explosives samples. Implementation of fast GC methods will be valuable in the future for defense and security forensics applications.

  19. Pixelated diffraction signatures for explosive detection

    Science.gov (United States)

    O'Flynn, Daniel; Reid, Caroline; Christodoulou, Christiana; Wilson, Matt; Veale, Matthew C.; Seller, Paul; Speller, Robert

    2012-06-01

    Energy dispersive X-ray diffraction (EDXRD) is a technique which can be used to improve the detection and characterisation of explosive materials. This study has performed EDXRD measurements of various explosive compounds using a novel, X-ray sensitive, pixelated, energy resolving detector developed at the Rutherford Appleton Laboratory, UK (RAL). EDXRD measurements are normally performed at a fixed scattering angle, but the 80×80 pixel detector makes it possible to collect both spatially resolved and energy resolved data simultaneously. The detector material used is Cadmium Telluride (CdTe), which can be utilised at room temperature and gives excellent spectral resolution. The setup uses characteristics from both energy dispersive and angular dispersive scattering techniques to optimise specificity and speed. The purpose of the study is to develop X-ray pattern "footprints" of explosive materials based on spatial and energy resolved diffraction data, which can then be used for the identification of such materials hidden inside packages or baggage. The RAL detector is the first energy resolving pixelated detector capable of providing an energy resolution of 1.0-1.5% at energies up to 150 keV. The benefit of using this device in a baggage scanner would be the provision of highly specific signatures to a range of explosive materials. We have measured diffraction profiles of five explosives and other compounds used to make explosive materials. High resolution spectra have been obtained. Results are presented to show the specificity of the technique in finding explosives within baggage.

  20. The Trouble With Bonds

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ In early June,global financial markets gyrated downwards in the wake of central banks'tough language on inflation.At one point bond prices reflected expectations of four rate hikes by the US Federal Reserve (Fed) in the next 12 months.As a result,the dollar firmed,oil prices stabilized,and yield curves flattened around the world.If all these inflation-fighting measures are real,the situation bodes well for bonds.But,I think otherwise.

  1. On the Violence of High Explosive Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Tarver, C M; Chidester, S K

    2004-02-09

    High explosive reactions can be caused by three general energy deposition processes: impact ignition by frictional and/or shear heating; bulk thermal heating; and shock compression. The violence of the subsequent reaction varies from benign slow combustion to catastrophic detonation of the entire charge. The degree of violence depends on many variables, including the rate of energy delivery, the physical and chemical properties of the explosive, and the strength of the confinement surrounding the explosive charge. The current state of experimental and computer modeling research on the violence of impact, thermal, and shock-induced reactions is reviewed.

  2. Techniques of industrial radiology in military explosives

    International Nuclear Information System (INIS)

    The use of industrial radiology techniques id very important for military explosive fabrication. The cylindrical-ogive bodies made in forged metal have their interior fulfilled with high melted explosive and they must explode when they reach the target. The granades, as these bodies are called, are thrown by cannons and their interior are submitted to high pressures and accelerations which can cause a premature detonation, in most case, in interior of tube, in case of they have defects in explosive mass. The origins of defects, its localization and classification presenting the techniques used and disposable in Brazil are discussed. (M.C.K.)

  3. Study on Property of Desensitized Explosive Film

    Institute of Scientific and Technical Information of China (English)

    李国新; 王晓丽; 焦清介; 刘淑珍

    2004-01-01

    The mechanical sensitivity, the critical thickness of detonation wave propagation and detonation velocity of desensitized PETN film were studied by experiments. The relationship between the mass of desensitizer paraffin wax and the friction sensitivity of desensitized PETN film was tested. According to the microstructure of film, the function of desensitizer was explained. It was proved that the explosive film could make explosive element micromation and kept its inherence properties by the result of testing the propagating critical dimension of the desensitized PETN film detonation wave. The explosive velocity of confined desensitized PETN film was tested by the multiplex optical fibre.

  4. Explosive Detection and Identification by PGNAA

    Energy Technology Data Exchange (ETDEWEB)

    E.H. Seabury; A.J. Caffrey

    2004-11-01

    The goal of this project was to determine the feasibility of using field-portable prompt gamma-ray neutron activation analysis (PGNAA) to detect and identify explosives in improvised nuclear devices (INDs). The studies were carried out using the Monte Carlo N-Particle (MCNP) code developed at Los Alamos National Laboratory. The model results were tested experimentally using explosive simulants and the PINS PGNAA system developed at Idaho National Engineering and Environmental Laboratory (INEEL). The results of the MCNP calculations and PINS measurements are presented in this report. The calculations and measurements were in good agreement and indicate that most explosives are readily distinguishable from one another.

  5. Explosive Detection and Identification by PGNAA

    International Nuclear Information System (INIS)

    The goal of this project was to determine the feasibility of using field-portable prompt gamma-ray neutron activation analysis (PGNAA) to detect and identify explosives in improvised nuclear devices (INDs). The studies were carried out using the Monte Carlo N-Particle (MCNP) code developed at Los Alamos National Laboratory. The model results were tested experimentally using explosive simulants and the PINS PGNAA system developed at Idaho National Engineering and Environmental Laboratory (INEEL). The results of the MCNP calculations and PINS measurements are presented in this report. The calculations and measurements were in good agreement and indicate that most explosives are readily distinguishable from one another

  6. Water waves generated by underwater explosion

    CERN Document Server

    Mehaute, Bernard Le

    1996-01-01

    This is the first book on explosion-generated water waves. It presents the theoretical foundations and experimental results of the generation and propagation of impulsively generated waves resulting from underwater explosions. Many of the theories and concepts presented herein are applicable to other types of water waves, in particular, tsunamis and waves generated by the fall of a meteorite. Linear and nonlinear theories, as well as experimental calibrations, are presented for cases of deep and shallow water explosions. Propagation of transient waves on dissipative, nonuniform bathymetries to

  7. Explosives detection: a challenge for physical chemistry.

    Science.gov (United States)

    Steinfeld, J I; Wormhoudt, J

    1998-01-01

    The detection of explosives, energetic materials, and their associated compounds for security screening, demining, detection of unexploded ordnance, and pollution monitoring is an active area of research. A wide variety of detection methods and an even wider range of physical chemistry issues are involved in this very challenging area. This review focuses on techniques such as optical and mass spectrometry and chromatography for detection of trace amounts of explosives with short response times. We also review techniques for detecting the decomposition fragments of these materials. Molecular data for explosive compounds are reviewed where available. PMID:15012428

  8. CdS-K2Ti4-xPbxO9复合物的制备及其光催化制氢%Preparation of CdS-pillared K2Ti4-xPbxO9 Composite Photocatalysts and Its Photocatalytic Property for Hydrogen Evolution

    Institute of Scientific and Technical Information of China (English)

    梁英华; 崔文权; 刘利; 李立业; 齐跃丽

    2013-01-01

    采用高温固相法合成铅掺杂的K2Ti4-xPbxO9,微波辅助通过酸交换、胺柱撑、离子交换等步骤制备了硫化镉(CdS)插层的K2Ti4-xPbxO9(CdS-K2Ti4-xPbxO9)复合光催化剂.催化剂的结构利用X射线粉末衍射、紫外-可见漫反射吸收光谱和X射线光电子能谱等进行表征.考察了CdS-K2Ti4-xPbxO9在紫外光及可见光下催化制氢活性.催化剂的可见光吸收范围在Pb掺杂和CdS插层共同作用下得到了扩展,光催化活性也随之提高.催化剂在紫外光和可见光下3h产氢量分别为150.43 mmol/(g cat)和2.43 mmol/(g eat).最后对光催化机理进行了分析.%The K2Ti4-χPbχO9 powder was prepared by a host compound method. CdS-intercalated K2Ti4-χPbχO9 composite photocatalysts (designated as CdS-K2Ti4-χPbχO9) were synthesized via the ion-exchange reaction, butylamine pillaring and sulfuration processes with the irradiation of microwave. The photocatalysts were determined by X-ray diffraction, ultraviolet-visible diffuse reflection spectra and X-ray photoelectron spectroscopy, respectively. The photocatalytic activities of CdS-K2Ti4-χPbχO9 for hydrogen evolution were also investigated under Ultraviolet (UV) and visible light irradiation. The results reveal that the Pb irons doping and CdS-intercalated K2Ti4-χPbχO9 photocatalysts can increase the range of absorb visible light and enhance the photocatalytic activity. The photocatalytic activities for hydrogen production of the CdS-intercalated K2Ti4-χPbχO9 were 150.43 mmol/(g cat) and 2.43 mmol/(g cat) under UV light and visible light irradiation after 3-h irradiation, respectively. In addition, the mechanism of photocataly-sis was discussed.

  9. Photochemical tissue bonding

    Science.gov (United States)

    Redmond, Robert W.; Kochevar, Irene E.

    2012-01-10

    Photochemical tissue bonding methods include the application of a photosensitizer to a tissue and/or tissue graft, followed by irradiation with electromagnetic energy to produce a tissue seal. The methods are useful for tissue adhesion, such as in wound closure, tissue grafting, skin grafting, musculoskeletal tissue repair, ligament or tendon repair and corneal repair.

  10. Thread bonds in molecules

    CERN Document Server

    Ivlev, B

    2015-01-01

    Unusual chemical bonds are proposed. Each bond is almost covalent but is characterized by the thread of a small radius $\\sim 0.6\\times 10^{-11}$cm, between two nuclei in a molecule. The main electron density is concentrated outside the thread as in a covalent bond. The thread is formed by the electron wave function which has a tendency to be singular on it. The singularity along the thread is cut off by electron "vibrations" due to the interaction with zero point electromagnetic oscillations. The electron energy has its typical value of (1-10)eV. Due to the small tread radius the uncertainty of the electron momentum inside the thread is large resulting in a large electron kinetic energy $\\sim 1 MeV$. This energy is compensated by formation of a potential well due to the reduction of the energy of electromagnetic zero point oscillations. This is similar to formation of a negative van der Waals potential. Thread bonds are stable and cannot be created or destructed in chemical or optical processes.

  11. Bonds Between Atoms.

    Science.gov (United States)

    Holden, Alan

    The field of inquiry into how atoms are bonded together to form molecules and solids crosses the borderlines between physics and chemistry encompassing methods characteristic of both sciences. At one extreme, the inquiry is pursued with care and rigor into the simplest cases; at the other extreme, suggestions derived from the more careful inquiry…

  12. Testing of aluminum stainless steel bonds for long-term storage

    International Nuclear Information System (INIS)

    At the 19th Meeting of JOWOG-12 experiments designed to test the compatibility and aging trends of aluminum-stainless steel bonds manufactured by three different techniques (silver brazed, explosive bonded and friction bonded) were described. The significant results obtained after 492 days of testing at 500, 700, and 900C and 462 days of testing under cycle temperature conditions between -300 and +700C are presented. Bond ultimate strength values have been fitted to a model to predict lifetime estimates for each of the bonds studied. Elemental depth profiles of the surfaces of fractured specimens, aged under cyclic conditions for 328 days, were obtained using argon ion sputtering and Auger Electron Spectroscopy. These studies showed where fracture occurred in specimens pulled for mechanical testing

  13. Supernova neutrinos and explosive nucleosynthesis

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-05-09

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

  14. Laser initiated endotracheal tube explosion.

    Science.gov (United States)

    De Vane, G G

    1990-06-01

    A 62-year-old male with a diagnosis of subglottic and tracheal stenosis resulting from a prolonged intubation was scheduled for a laser bronchoscopy and placement of a silicon T-shaped tube. His history was significant for two myocardial infarctions, an episode of congestive heart failure and exertional angina. A 6 mm polyvinyl chloride endotracheal tube, wrapped with aluminum tape, was placed in an existing tracheostomy stoma. During the course of the procedure, a sudden bright flash occurred followed by an explosive noise and black smoke rising in the anesthesia circuit and from the patient's mouth. The endotracheal tube was removed and the patient was treated for first and second degree burns in the supraglottic area and base of the tongue. In laser surgery of the airway, special care should be given to reducing the flammability of the inspired gases which can be best accomplished by the mixture of helium with oxygen. Helium acts to retard ignition of polyvinyl chloride tubes in concentrations of 60% or greater. The external surface of the tube can also be protected with the application of a metallic tape affixed in a spiral fashion. Finally, a protocol for the management and treatment of this emergency should be adopted and rehearsed. PMID:2378234

  15. Asymmetric Explosions of Thermonuclear Supernovae

    CERN Document Server

    Ghezzi, C R; Horváth, J E

    2004-01-01

    A type Ia supernova explosion starts in a white dwarf as a laminar deflagration at the center of the star and soon several hydrodynamic instabilities (in particular, the Rayleigh-Taylor (R-T) instability) begin to act. In previous work (Ghezzi, de Gouveia Dal Pino, & Horvath 2001), we addressed the propagation of an initially laminar thermonuclear flame in presence of a magnetic field assumed to be dipolar. We were able to show that, within the framework of a fractal model for the flame velocity, the front is affected by the field through the quenching of the R-T instability growth in the direction perpendicular to the field lines. As a consequence, an asymmetry develops between the magnetic polar and the equatorial axis that gives a prolate shape to the burning front. We have here computed numerically the total integrated asymmetry as the flame front propagates outward through the expanding shells of decreasing density of the magnetized white dwarf progenitor, for several chemical compositions, and found...

  16. Glossary on peaceful nuclear explosions terms

    International Nuclear Information System (INIS)

    The report presents a glossary of terms in the area of peaceful nuclear explosions. The terms are in English, French, Russian and Spanish with cross-references for the corresponding terms of the other languages

  17. Pretreatment of Corn Stalk by Steam Explosion

    Institute of Scientific and Technical Information of China (English)

    邵自强; 田永生; 谭惠民

    2003-01-01

    A steam explosion pretreatment, which is one of the best ways of pretreating plant stalk, is applied at various severities to corn stalk. It could effectively modify the super-molecular structure of corn stalk and defibrating corn stalk into individual components. The relationship between yield of reducing sugar and the operating conditions, including temperature, pressure of steam explosion pretreatment and acidity, is also established. Experimental results prove that the steam explosion substantially increases the yield of reducing sugar, and the optimal condition for steam explosion is as follows: the pressure is 2.0 MPa, the pressure-retaining time 300 s, the initial acid concentration 1% and the acid treatment time 24 h.

  18. Magnetorotational Explosive Instability in Keplerian Disks

    CERN Document Server

    Shtemler, Yuri; Mond, Michael

    2015-01-01

    In this paper it is shown that deferentially rotating disks that are in the presence of weak axial magnetic field are prone to a new nonlinear explosive instability. The latter occurs due to the near-resonance three-wave interactions of a magnetorotational instability with stable Alfven-Coriolis and magnetosonic modes. The dynamical equations that govern the temporal evolution of the amplitudes of the three interacting modes are derived. Numerical solutions of the dynamical equations indicate that small frequency mismatch gives rise to two types of behavior: 1. explosive instability which leads to infinite values of the three amplitudes within a finite time, and 2. bounded irregular oscillations of all three amplitudes. Asymptotic solutions of the dynamical equations are obtained for the explosive instability regimes and are shown to match the numerical solutions near the explosion time.

  19. Corona-discharge-initiated mine explosions

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-10-01

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

  20. Optical chemosensors and reagents to detect explosives

    OpenAIRE

    Salinas Soler, Yolanda; Martínez Mañez, Ramón; Marcos Martínez, María Dolores; Sancenón Galarza, Félix; Costero Nieto, Ana Maria; PARRA ALVAREZ, MARGARITA; GIL GRAU, SALVADOR

    2012-01-01

    This critical review is focused on examples reported from 1947 to 2010 related to the design of chromo-fluorogenic chemosensors and reagents for explosives (141 references). © 2012 The Royal Society of Chemistry.

  1. Rabbit lung injury induced by explosive decompression

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: To study the mechanism of rabbit lunginjury caused by explosive decompression. Methods: A total of 42 rabbits and 10 rats were served as the experimental animals. A slow recompressiondecompression test and an explosive decompression test were applied to the animals, respectively. And the effects of the given tests on the animals were discussed. Results: The slow recompression-decompression did not cause an obvious lung injury, but the explosive decompression did cause lung injuries in different degrees. The greater the decompression range was, the shorter the decompression duration was, and the heavier the lung injuries were. Conclusions: Explosive decompression can cause a similar lung injury as shock wave does. The primary mechanical causes of the lung injury might be a tensile strain or stress in the alveolar wall and the pulmonary surface's impacts on the inside wall of the chest.

  2. Unreacted Hugoniots for porous and liquid explosives

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-08-01

    Numerous authors have measured the Hugoniots of a variety of granular explosives pressed to different densities. Each explosive at each density was typically then treated as a unique material having its own Hugoniot. By combining methods used by Hayes, Sheffield and Mitchell (for describing the Hugoniot of HNS at various densities) with Hermann`s P-{alpha} model, it is only necessary to know some thermodynamic constants or the Hugoniot of the initially solid material and the porous material sound speed to obtain accurate unreacted Hugoniots for the porous explosive. We discuss application of this method to several materials including HMX, PETN, TNT, and Tetryl, as well as HNS. We also show that the ``Universal Liquid Hugoniot`` can be used to calculate the unreacted Hugoniot for liquid explosives. With this method only the ambient pressure sound speed and density are needed to predict the Hugoniot. Applications presented include nitromethane and liquid TNT.

  3. Traumatic corneal endothelial rings from homemade explosives.

    Science.gov (United States)

    Ng, Soo Khai; Rudkin, Adam K; Galanopoulos, Anna

    2013-08-01

    Traumatic corneal endothelial rings are remarkably rare ocular findings that may result from blast injury. We present a unique case of bilateral traumatic corneal endothelial rings secondary to blast injury from homemade explosives. PMID:23474743

  4. Explosives Detection and Identification by PGNAA

    Energy Technology Data Exchange (ETDEWEB)

    E. H. Seabury; A. J. Caffrey

    2006-04-01

    The feasibility of using field-portable prompt gamma-ray neutron activation analysis (PGNAA) to detect and identify explosives in improvised nuclear devices has been studied computationally, using the Monte Carlo N-Particle (MCNP) code developed at Los Alamos National Laboratory. The Monte Carlo results, in turn were tested experimentally using explosive simulants and the PINS PGNAA system developed at Idaho National Laboratory (INL). The results of the MCNP calculations and PINS measurements have been previously reported. In this report we describe measurements performed on actual explosives and compare the results with calculations. The calculations and measurements were in good agreement and indicate that most explosives are readily distinguishable from one another by PGNAA

  5. Explosives Detection and Identification by PGNAA

    International Nuclear Information System (INIS)

    The feasibility of using field-portable prompt gamma-ray neutron activation analysis (PGNAA) to detect and identify explosives in improvised nuclear devices has been studied computationally, using the Monte Carlo N-Particle (MCNP) code developed at Los Alamos National Laboratory. The Monte Carlo results, in turn were tested experimentally using explosive simulants and the PINS PGNAA system developed at Idaho National Laboratory (INL). The results of the MCNP calculations and PINS measurements have been previously reported. In this report we describe measurements performed on actual explosives and compare the results with calculations. The calculations and measurements were in good agreement and indicate that most explosives are readily distinguishable from one another by PGNAA

  6. Numerical Simulation of Underwater Explosion Loads

    Institute of Scientific and Technical Information of China (English)

    XIN Chunliang; XU Gengguang; LIU Kezhong

    2008-01-01

    Numerical simulation of TNT underwater explosion was carried out with AUTODYN software.Influences of artificial viscosity and mesh density on simulation results were discussed.Detonation waves in explosive and shock wave in water during early time of explosion are high frequency waves.Fine meshes (less than 1 mm) in explosive and water nearby,and small linear viscosity coefficients and quadratic viscosity coefficients (0.02 and 0.1 respectively,1/10 of default values) are needed in numerical simulation model.According to these rules,numerical computing pressure profiles can match well with those calculated by Zamyshlyayev empirical formula.Otherwise peak pressure would be smeared off and upstream relative errors would be cumulated downstream to make downstream peak pressure lower.

  7. 30 CFR 77.1300 - Explosives and blasting.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Explosives and blasting. 77.1300 Section 77... Explosives and Blasting § 77.1300 Explosives and blasting. (a) No explosives, blasting agent, detonator, or any other related blasting device or material shall be stored, transported, carried, handled,...

  8. Paralogy mapping: Identification of a region in the human MHC triplicated onto human chromosomes 1 and 9 allows the prediction and isolation of novel PBX and NOTCH loci

    Energy Technology Data Exchange (ETDEWEB)

    Katsanis, N.; Fisher, E.M.C. [Imperial College of Medicine at St. Mary`s, London (United Kingdom); Fitzgibbon, J. [Institute of Ophthalmology, London (United Kingdom)

    1996-07-01

    The human genome contains a group of gene families whose members map within the same regions of chromosomes 1, 6, and 9. The number of gene families involved and their pronounced clustering to the same areas of the genome indicate that their mapping relationship in nonrandom. By combining mapping data and sequence information for the gene families, we have determined that these sequences are part of a large region that spans several megabases. This region is present in three copies: on the long arm of human chromosome 1, the short arm of chromosome 6, and the long arm of chromosome 9. We have characterized the phylogenesis of two of the gene families involved and propose an evolutionary route for the creation of the three regions. Our analysis led us to predict and demonstrate the presence of two loci, a PBX locus on chromosome 6 and a NOTCH locus on chromosome 1. The discovery of this triplicated region increases our understanding of the evolution of the human genome and may have considerable practical implications for gene mapping prediction and novel approaches to isolating new gene family members and uncloned disease loci. 32 refs., 4 figs., 2 tabs.

  9. Influence of dopant concentration on the structure and physical properties of Nd1-xPbxMnO3 single crystals

    International Nuclear Information System (INIS)

    The structure of Nd1-xPbxMnO3 crystal for x=0.25 is determined at room temperature by single-crystal X-ray diffraction. The structural refinement reveals that the crystal is tetragonal with space group P4/mmm, Z=4 and R of 8.3%. The lattice parameters are a=7.7652(1)A, c=3.884(1)A and α=β=γ=90 deg. The structural analysis is then extended to x=0.38. It is noticed that substitution of Pb at the Nd site results in structural phase change from tetragonal (x=0.25) to cubic (x=0.38). These changes are attributed to the progressive removal of inter-octahedral tilting and minimization of the octahedral distortion leading to a higher symmetry as doping concentration increases. While the unit cell volume of tetragonal structure (P4/mmm) is comparable to that of parent NdMnO3 (Pnma), the volume of cubic unit cell (Pm3-bar m) is doubled. Electron diffraction patterns support these results and rule out the possibility of twinning. Changes in transport properties as a function of temperature at different doping levels are in accordance with the observed structural changes. It is observed that Tθ and TMI increase with x

  10. HMX基PBX的作功能力及其JWL状态方程%Power Ability and JWL Equation of State of a HMX-based PBX

    Institute of Scientific and Technical Information of China (English)

    谭凯元; 韩勇; 罗观; 殷明; 黄毅民; 卢校军

    2013-01-01

    为研究HMX基PBX(90/10-HMX/黏结剂)的作功能力和爆轰产物状态方程,通过25 mm标准圆筒试验,得到该炸药的作功能力特征参量以及格尼速度(2.80 mm/μs).用非线性有限元动力学程序ANSYS/LS-DYNA对圆筒试验进行了数值计算.通过计算值与试验结果进行对比和调整的方法得到HMX基PBX的爆轰产物JWL状态方程参数,通过炸药驱动平板飞片试验和数值计算对这些参数进行了验证.计算值与实验结果吻合,表明圆筒试验得到的爆轰产物JWL状态方程参数是有效的.

  11. Shapiro Step Response of Intrinsic Josephson Junctions of (Bi1-xPbx)2Sr2CaCu2Oy at Elevated Temperatures

    Science.gov (United States)

    Oya, G.; Miyasaka, T.; Kitamura, M.; Irie, A.

    We have studied the response of stacks of intrinsic Josephson junctions (IJJs) of (Bi1-xPbx)2Sr2CaCu2Oy (x = 0.15) to injection of microwave of frequencies frf of 2-20 GHz at 4.2 K and higher temperatures. Clear constant voltage steps, which are considered Shapiro steps, are successfully observed on the current-voltage characteristic of an IJJ with a resistivity of Josephson-vortex flow Rfl in any stack under the injection of microwave. The step of the eighth order, which is the highest in this study, is observed from the largest IJJ under injection of microwave of 10 GHz at 4.2 K. But, as the temperature increases, the number of steps decreases, and finally the steps disappear at ∼45 K due to large self-heating. In this IJJ a low Rfl plays an important role in appearance of the steps of the high order. The typical behavior of the steps at 4.2 K is well reproduced by numerical simulations on that of Shapiro steps of a JJ with the shunt resistivity equal to Rfl at the temperature.

  12. Electronic tuning of the transport properties of off-stoichiometric PbxSn1−xTe thermoelectric alloys by Bi2Te3 doping

    International Nuclear Information System (INIS)

    The recent energy demands affected by the dilution of conventional energy resources and the growing awareness of environmental considerations had motivated many researchers to seek for novel renewable energy conversion methods. Thermoelectric direct conversion of thermal into electrical energies is such a method, in which common compositions include IV-VI semiconducting compounds (e.g., PbTe and SnTe) and their alloys. For approaching practical thermoelectric devices, the current research is focused on electronic optimization of off-stoichiometric p-type PbxSn1−xTe alloys by tuning of Bi2Te3 doping and/or SnTe alloying levels, while avoiding the less mechanically favorable Na dopant. It was shown that upon such doping/alloying, higher ZTs, compared to those of previously reported undoped Pb0.5Sn0.5Te alloy, were obtained at temperatures lower than 210–340 °C, depending of the exact doping/alloying level. It was demonstrated that upon optimal grading of the carrier concentration, a maximal thermoelectric efficiency enhancement of ∼38%, compared to that of an undoped material, is expected

  13. Remote monitoring of nuclear explosions during radio sounding of ionosphere over explosion place

    International Nuclear Information System (INIS)

    To solve the problem of non propagation of nuclear weapons it is necessary to develop the methods of remote detecting and monitoring of underground nuclear explosions too. At present , the basic method of underground nuclear explosions monitoring is seismic method. Because of decreasing of boundary of explosion power and development methods to decrease of seismic efficacy of explosions it is necessary the further development both as a seismic method as new independent methods of underground nuclear explosions monitoring. So the remote monitoring of explosions with helping radio physical method for measurement of slight blast waves over explosion place is promising. To determine all possibilities of that method it is necessary to work off the model of physical processes with using of experimental material. At the same time we can tell about some advantages of present method. The measurement of disturbance is releasing over explosion place and it does not depend from length of radio trace. Then seismic method measures the vibration of point of earth surface. Ionospheric method is integral method: the disturbances of ionosphere are produced by the whole epicenter region of explosion. As a result, the space inhomogeneities are averaging and the influence of stochastic factors is decreasing

  14. Effect of Explosive Sources on the Elastic Wave Field of Explosions in Soils

    Directory of Open Access Journals (Sweden)

    Chun Hua Bai

    2013-07-01

    Full Text Available A seismic wave is essentially an elastic wave, which propagates in the soil medium, with the strength of initial elastic wave being created by an explosion source that has a significant effect on seismic wave energy. In order to explore the explosive energy effect on output characteristics of the elastic wave field, four explosives with different work capacity (i.e., TNT, 8701, composition B and THL were used to study the effects of elastic wave pressure and rise time of stress wave to the peak value of explosions in soils. All the experimental data was measured under the same geological conditions using a self-designed pressure measuring system. This study was based on the analysis of the initial pressure of elastic waves from the energy output characteristics of the explosives. The results show that this system is feasible for underground pressure tests, and the addition of aluminum powder increases the pressure of elastic waves and energy release of explosions in soils. The explosive used as a seismic energy source in petroleum and gas exploration should have properties of high explosion heat and low volume of explosion gas products.Defence Science Journal, 2013, 63(4, pp.376-380, DOI:http://dx.doi.org/10.14429/dsj.63.2770

  15. Effect of Explosive Sources on the Elastic Wave Field of Explosions in Soils

    Directory of Open Access Journals (Sweden)

    Chun-Hua Bai

    2013-07-01

    Full Text Available A seismic wave is essentially an elastic wave, which propagates in the soil medium, with the strength of initial elastic wave being created by an explosion source that has a significant effect on seismic wave energy. In order to explore the explosive energy effect on output characteristics of the elastic wave field, four explosives with different work capacity (i.e., TNT, 8701, composition B and THL were used to study the effects of elastic wave pressure and rise time of stress wave to the peak value of explosions in soils. All the experimental data was measured under the same geological conditions using a self-designed pressure measuring system. This study was based on the analysis of the initial pressure of elastic waves from the energy output characteristics of the explosives. The results show that this system is feasible for underground pressure tests, and the addition of aluminum powder increases the pressure of elastic waves and energy release of explosions in soils. The explosive used as a seismic energy source in petroleum and gas exploration should have properties of high explosion heat and low volume of explosion gas products.

  16. Wave generations from confined explosions in rocks

    OpenAIRE

    C. L. Liu; Ahrens, Thomas J.

    1998-01-01

    In order to record P- and S-waves generated from confined explosions in rocks in the laboratory, a method is developed based on the interactions between incident P- and SV-waves and free-surfaces of rocks. The relations between particle displacements of incident P- and SV-waves, and the strains measured using strain gauges attached on free-surfaces of rocks are analytically derived. P- and SV-waves generated from confined explosions in Bedford limestone are recorded.

  17. Scaling the electromagnetically driven explosive shock simulator

    Science.gov (United States)

    Persh, Robert I.

    1987-01-01

    A heavy payload electromagnetically driven explosive shock simulator, referred to as EDESS-3, has been assembled and characterized at the Navel research Weapons Center. EDESS-3 is the logical outgrowth of the earlier EDESS 1 and 2 simulator work which explored the use of electrical pulse power technology for the generation of explosive like shocks. The features of the EDESS-3 are presented, and designs for the next generation of EDESS machines are introduced.

  18. Managing traumatic brain injury secondary to explosions

    Directory of Open Access Journals (Sweden)

    Burgess Paula

    2010-01-01

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

  19. Weapons Experiments Division Explosives Operations Overview

    Energy Technology Data Exchange (ETDEWEB)

    Laintz, Kenneth E. [Los Alamos National Laboratory

    2012-06-19

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

  20. The ionospheric effects of industrial explosions

    Science.gov (United States)

    Varshavskii, I. I.; Kalikhman, A. D.

    1984-04-01

    A mathematical model is developed which describes the effect of an industrial explosion on the parameters of a radio signal reflected from the ionosphere. The model predictions are shown to be in good agreement with the observed Doppler shift and angle of arrival of radio signals for actual explosions near Alma-Ata and Sliudianka. Estimates are made of the amplitude and shape of a perturbation wave at the heights of the F layer.

  1. Did Gamma Ray Burst Induce Cambrian Explosion?

    OpenAIRE

    Chen, Pisin; Ruffini, Remo

    2014-01-01

    One longstanding mystery in bio-evolution since Darwin's time is the origin of the Cambrian explosion that happened around 540 million years ago (Mya), where an extremely rapid increase of species occurred. Here we suggest that a nearby GRB event ~500 parsecs away, which should occur about once per 5 Gy, might have triggered the Cambrian explosion. Due to a relatively lower cross section and the conservation of photon number in Compton scattering, a substantial fraction of the GRB photons can...

  2. Explosion and detonation characteristics of dimethyl ether.

    Science.gov (United States)

    Mogi, Toshio; Horiguchi, Sadashige

    2009-05-15

    In this study, the explosion and detonation characteristics of dimethyl ether (DME) were experimentally investigated. A spherical pressure vessel with an internal volume of 180L was used as the explosion vessel. Therefore, tubes 10m in length with internal diameters of 25mm and 50mm were used as detonation tubes. In addition, we compared the characteristics of DME with those of propane since DME is considered as a substitute fuel for liquid petroleum gas (LPG). At room temperature and atmospheric pressure, the maximum explosive pressure increased tenfold. The explosion index (K(G) values), an indicator of the intensity of an explosion, was larger than that of propane, indicating that the explosion was intense. No experimental study has been conducted on the detonation behavior of DME so far, but this research confirmed a transition to detonation. The detonation characteristics were similar to the characteristics of the Chapman-Jouguet detonation, and the concentration range for detonation was from 5.5% to 9.0%. PMID:18774641

  3. Risk Assessment Study for Storage Explosive

    Directory of Open Access Journals (Sweden)

    S. S. Azhar

    2006-01-01

    Full Text Available In Malaysia, there has been rapidly increasing usage in amount of explosives due to widely expansion in quarrying and mining industries. The explosives are usually stored in the storage where the safety precaution had given high attention. As the storage of large quantity of explosive can be hazardous to workers and nearby residents in the events of accidental denotation of explosives, a risk assessment study for storage explosive (magazine had been carried out. Risk assessment study had been conducted in Kimanis Quarry Sdn. Bhd, located in Sabah. Risk assessment study had been carried out with the identification of hazards and failure scenarios and estimation of the failure frequency of occurrence. Analysis of possible consequences of failure and the effects of blast waves due to the explosion was evaluated. The risk had been estimated in term of fatalities and eardrum rupture to the workers and public. The average individual voluntary risk for fatality to the workers at the quarry is calculated to be 5.75 x 10-6 per person per year, which is much lower than the acceptable level. Eardrum rupture risk calculated to be 3.15 x 10-6 per person per year for voluntary risk. There is no involuntary risk found for fatality but for eardrum rupture it was calculated to be 6.98 x 10-8 per person per year, as given by Asian Development Bank.

  4. Screening sealed bottles for liquid explosives

    Science.gov (United States)

    Kumar, Sankaran; McMichael, W. Casey; Kim, Y.-W.; Sheldon, Alan G.; Magnuson, Erik E.; Ficke, L.; Chhoa, T. K.; Moeller, C. R.; Barrall, Geoffrey A.; Burnett, Lowell J.; Czipott, Peter V.; Pence, J. S.; Skvoretz, David C.

    1997-01-01

    A particularly disturbing development affecting transportation safety and security is the increasing use of terrorist devices which avoid detection by conventional means through the use of liquid explosives and flammables. The hazardous materials are generally hidden in wine or liquor bottles that cannot be opened routinely for inspection. This problem was highlighted by the liquid explosives threat which disrupted air traffic between the US an the Far East for an extended period in 1995. Quantum Magnetics has developed a Liquid Explosives Screening systems capable of scanning unopened bottles for liquid explosives. The system can be operated to detect specific explosives directly or to verify the labeled or bar-coded contents of the container. In this system, magnetic resonance (MR) is used to interrogate the liquid. MR produces an extremely rich data set and many characteristics of the MR response can be determined simultaneously. As a result, multiple MR signatures can be defined for any given set of liquids, and the signature complexity then selected according to the level of threat. The Quantum Magnetics Liquid Explosives Screening System is currently operational. Following extensive laboratory testing, a field trial of the system was carried out at the Los Angeles International Airport.

  5. Explosive compaction of CuCr alloys

    Institute of Scientific and Technical Information of China (English)

    李金平; 罗守靖; 龚朝晖; 牛玮; 纪松

    2002-01-01

    The production of CuCr alloys utilizing explosive compaction was studied. Mixture powders of CuCr alloys placed in tubes with a dimension of d14.0mm×21.4mm can be compacted using explosive pads of 16.5mm or 22.5mm. Thicker pads of explosive make the compacts more porous. The effects of the ratio of me/mp, ratio of me/(mp+mt) and impact energy on the density of compacts were similar, they were chosen to control explosive compaction, respectively. When adequate value of the parameters me/mp, me/(mt+mp) and impact energy of unit area of tube was chosen, high density(7.858g/cm3), high hardness(HB189) and low conductance (13.6MS/m) of CuCr alloys could be made by explosive compaction. The general properties of CuCr alloys by explosive compaction are similar to those of CuCr alloys by traditional process.

  6. Spectroscopic characterization of nitroaromatic landmine signature explosives

    Science.gov (United States)

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

    2004-09-01

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

  7. THE BIGGEST EXPLOSIONS IN THE UNIVERSE

    International Nuclear Information System (INIS)

    Supermassive primordial stars are expected to form in a small fraction of massive protogalaxies in the early universe, and are generally conceived of as the progenitors of the seeds of supermassive black holes (BHs). Supermassive stars with masses of ∼55, 000 M☉, however, have been found to explode and completely disrupt in a supernova (SN) with an energy of up to ∼1055 erg instead of collapsing to a BH. Such events, ∼10, 000 times more energetic than typical SNe today, would be among the biggest explosions in the history of the universe. Here we present a simulation of such a SN in two stages. Using the RAGE radiation hydrodynamics code, we first evolve the explosion from an early stage through the breakout of the shock from the surface of the star until the blast wave has propagated out to several parsecs from the explosion site, which lies deep within an atomic cooling dark matter (DM) halo at z ≅ 15. Then, using the GADGET cosmological hydrodynamics code, we evolve the explosion out to several kiloparsecs from the explosion site, far into the low-density intergalactic medium. The host DM halo, with a total mass of 4 × 107 M☉, much more massive than typical primordial star-forming halos, is completely evacuated of high-density gas after ∼☉ after ∼> 70 Myr. The chemical signature of supermassive star explosions may be found in such long-lived second-generation stars today

  8. Experimental Study on Unconfined Vapor Cloud Explosion

    Institute of Scientific and Technical Information of China (English)

    毕明树; ABULITI; Abudula

    2003-01-01

    An experimental system was setup to study the pressure field of unconfined vapor cloud explosions.The semi-spherical vapor clouds were formed by slotted 0.02mm polyethylene film.In the Center of the cloud was an ignition electrode that met ISO6164"Explosion protection System" and NFPA68 "Guide for Venting of Deflagrations". A data-acquisition system,with dymame responding time less than 0.001s with 0.5% accuracy,recorded the pressure-time diagram of acetylene-air mixture explosion with stoichiometrical ratio.The initial cloud diameters varied from 60cm to 300cm.Based on the analysis of experimental data,the quantitative relationship is obtained for the cloud explosion pressure,the cloud radius and the distance from ignition point .Present results provide a useful way to evaluate the building damage caused by unconfined vapor cloud explosions and to determine the indispensable explosion grade in the application of multi-energy model.

  9. Solid Rocket Launch Vehicle Explosion Environments

    Science.gov (United States)

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

    2014-01-01

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

  10. Statistical estimation of loads from gas explosions

    Energy Technology Data Exchange (ETDEWEB)

    Hoeiset, Stian

    1998-12-31

    In the design of structures in the offshore and process industries, the possibility of a gas explosion must always be considered. The main uncertainties in computerized simulation of gas explosions are the assumptions of the gas cloud, the location of the ignition point and the properties of the simulator itself. This thesis quantifies the levels of these uncertainties by performing a large number of simulations on three offshore modules and one onshore plant. It is found that (1) there is an approximate linear relation between pressure and gas volume, (2) it may be possible to find a linear relation between pressure and impulse, (3) there is an inverse relation between pressure and duration, (4) the response of offshore structures exposed to gas explosions are rarely in the impulsive regime, (5) loading rates vary widely in magnitude, (6) an assumption of a triangular explosion pulse is often correct, (7) louvres increase pressure, impulse and duration of an explosion. The effect of ignition point location is studied in detail. It is possible to derive an ignition point uncertainty load factor that shows predictable behaviour by generalizing the non-parametric properties of the explosion pressure. A model for taking into account the uncertainties regarding gas volume, ignition point location and simulator imperfectness is proposed. The model is intended to produce a characteristic load for structural design. 68 refs., 51 figs., 36 tabs.

  11. Explosive vapor detection payload for small robots

    Science.gov (United States)

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

    2013-05-01

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

  12. Convertible bond valuation focusing on Chinese convertible bond market

    OpenAIRE

    Yang, Ke

    2010-01-01

    This paper mainly discusses the methods of valuation of convertible bonds in Chinese market. Different from common convertible bonds in European market, considering the complicate features of Chinese convertible bond, this paper represents specific pricing approaches for pricing convertible bonds with different provisions along with the increment of complexity of these provisions. More specifically, this paper represents the decomposing method and binomial tree method for pricing both of Non-...

  13. Indirect bonding technique in orthodontics

    Directory of Open Access Journals (Sweden)

    Kübra Yıldırım

    2016-08-01

    Full Text Available ‘Direct Bonding Technique’ which allows the fixed orthodontic appliances to be directly bonded to teeth without using bands decreased the clinic time for bracket bonding and increased esthetics and oral hygiene during orthodontic treatment. However, mistakes in bracket positioning were observed due to decreased direct visual sight and access to posterior teeth. ‘Indirect Bonding Technique’ was developed for eliminating these problems. Initially, decreased bond strength, higher bond failure rate, periodontal tissue irritation, compromised oral hygiene and increased laboratory time were the main disadvantages of this technique when compared to direct bonding. The newly developed materials and modified techniques help to eliminate these negative consequences. Today, the brackets bonded with indirect technique have similar bond strength with brackets bonded directly. Moreover, indirect and direct bonding techniques have similar effects on periodontal tissues. However, indirect bonding technique requires more attention and precision in laboratory and clinical stage, and has higher cost. Orthodontist's preference between these two bonding techniques may differ according to time spent in laboratory and clinic, cost, patient comfort and personal opinion.

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

    Science.gov (United States)

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

    2012-02-01

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

  15. Review of the weldability window concept and equations for explosive welding

    International Nuclear Information System (INIS)

    Explosive cladding/welding is usually considered a solid state process in which the detonation of a certain amount of an explosive composition is used to accelerate one of the materials to be weld against the other in order to promote a high velocity oblique collision that will be responsible for bonding the materials. The conditions that should be met to achieve good welds define what is called as a weldability window or criteria. A weldability criteria based on the collision point velocity (Vc) and on the collision angle (β) is the most used today. In the β-Vc space the weldability window is defined by four lines or limits. Despite of its wide used in explosive welding works, neither the concepts behind those limits neither the equations used to define them in the β-Vc space are particularly clear. Contradictory concepts, and equations with undefined variables or parameters, are commonly found in the literature. This paper aims to clarify those concepts and equations through an integrated description of the weldability limits and a reviewed presentation of the associated equations with the variables and parameters, including their units, clearly defined. The reviewed concepts and equations are then used for the description of the explosive weld of stainless steel to carbon steel in cylindrical configuration.

  16. A method for fast safety screening of explosives in terms of crystal packing and molecular stability.

    Science.gov (United States)

    Hu, Xiaohua; Chen, Nana; Li, Weichen

    2016-07-01

    Safety prediction is crucial to the molecular design or the material design of explosives, and the predictions based on any single factor alone will cause much inaccuracy, leading to a desire for a method on multi-bases. The presented proposes an improved method for fast screening explosive safety by combining a crystal packing factor and a molecular one, that is, steric hindrance against shear slide in crystal and molecular stability, denoted by intermolecular friction symbol (IFS) and bond dissociation energy (BDE) of trigger linkage respectively. Employing this BDE-IFS combined method, we understand the impact sensitivities of 24 existing explosives, and predict those of two energetic-energetic cocrystals of the observed CL-20/BTF and the supposed HMX/TATB. As a result, a better understanding is implemented by the combined method relative to molecular stability alone, verifying its improvement of more accurate predictions and the feasibility of IFS to graphically reflect molecular stacking in crystals. Also, this work verifies that the explosive safety is strongly related with its crystal stacking, which determines steric hindrance and influences shear slide. PMID:27365051

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

    OpenAIRE

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

    2006-01-01

    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. The technology of initiation devices used for mi...

  18. Explosions in Majestic Spiral Beauties

    Science.gov (United States)

    2004-12-01

    Images of beautiful galaxies, and in particular of spiral brethren of our own Milky Way, leaves no-one unmoved. It is difficult indeed to resist the charm of these impressive grand structures. Astronomers at Paranal Observatory used the versatile VIMOS instrument on the Very Large Telescope to photograph two magnificent examples of such "island universes", both of which are seen in a southern constellation with an animal name. But more significantly, both galaxies harboured a particular type of supernova, the explosion of a massive star during a late and fatal evolutionary stage. The first image (PR Photo 33a/04) is of the impressive spiral galaxy NGC 6118 [1], located near the celestial equator, in the constellation Serpens (The Snake). It is a comparatively faint object of 13th magnitude with a rather low surface brightness, making it pretty hard to see in small telescopes. This shyness has prompted amateur astronomers to nickname NGC 6118 the "Blinking Galaxy" as it would appear to flick into existence when viewed through their telescopes in a certain orientation, and then suddenly disappear again as the eye position shifted. There is of course no such problem for the VLT's enormous light-collecting power and ability to produce sharp images, and this magnificent galaxy is here seen in unequalled detail. The colour photo is based on a series of exposures behind different optical filters, obtained with the VIMOS multi-mode instrument on the 8.2-m VLT Melipal telescope during several nights around August 21, 2004. About 80 million light-years away, NGC 6118 is a grand-design spiral seen at an angle, with a very small central bar and several rather tightly wound spiral arms (it is classified as of type "SA(s)cd" [2]) in which large numbers of bright bluish knots are visible. Most of them are active star-forming regions and in some, very luminous and young stars can be perceived. Of particular interest is the comparatively bright stellar-like object situated directly

  19. China-Russia Bond

    Institute of Scientific and Technical Information of China (English)

    Ji Zhiye; Ma Zongshi

    2007-01-01

    @@ Thanks to China's successful launching of the Year of Russia, 2006 will surely go down as a milestone in the history of the China-Russia bond. Furthermore, a still-warmer climate will continue to prevail in 2007 when Moscow, in its turn, hosts the Year of China, trying to outshine its next-door neighbor in this regard, as Russian President Vladimir Putin promised in the exchange of new year greetings with his Chinese counterpart, President Hu Jintao.

  20. Direct bonded space maintainers.

    Science.gov (United States)

    Santos, V L; Almeida, M A; Mello, H S; Keith, O

    1993-01-01

    The aim of this study was to evaluate clinically a bonded space maintainer, which would reduce chair-side time and cost. Sixty appliances were fabricated from 0.7 mm stainless steel round wire and bonded using light-cured composite to the two teeth adjacent to the site of extraction of a posterior primary tooth. Twenty males and sixteen females (age range 5-9-years-old) were selected from the Pedodontic clinic of the State University of Rio de Janeiro. The sixty space maintainers were divided into two groups according to the site in which they were placed: a) absent first primary molar and b) absent second primary molar. Impressions and study models were obtained prior to and 6 months after bonding the appliances. During this period only 8.3% of failures were observed, most of them from occlusal or facial trauma. Student t-test did not show statistically significant alterations in the sizes of the maintained spaces during the trial period.

  1. Coulombic Models in Chemical Bonding.

    Science.gov (United States)

    Sacks, Lawrence J.

    1986-01-01

    Compares the coulumbic point charge model for hydrogen chloride with the valence bond model. It is not possible to assign either a nonpolar or ionic canonical form of the valence bond model, while the covalent-ionic bond distribution does conform to the point charge model. (JM)

  2. Mittal bonded tongue thrusting appliance

    Directory of Open Access Journals (Sweden)

    Rekha Mittal

    2014-01-01

    Full Text Available These days majority of orthodontist includes bonded molar attachment in their inventory to eliminate the discomfort of molar separation during initial appointment and band spaces left at the end of treatment. This article describes a innovative and economical method of attachment of bonded tongue crib if required during the initial or later stages of treatment along with bonded molar tubes.

  3. Hamiltonian formulation of bond graphs

    NARCIS (Netherlands)

    Golo, Goran; Schaft, van der Arjan; Breedveld, Peter C.; Maschke, Bernhard M.; Johansson, R.; Rantzer, A.

    2003-01-01

    This paper deals with the mathematical formulation of bond graphs. It is proven that the power continuous part of bond graphs, the junction structure, can be associated with a Dirac structure and that the equations describing a bond graph model correspond to a port Hamiltonian system. The conditions

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-10-01

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

  5. Explosion characteristics of methane for CFD modeling and simulation of turbulent gas flow behavior during explosion

    Science.gov (United States)

    Skřínský, Jan; Vereš, Ján; Peer, Václav; Friedel, Pavel

    2016-06-01

    The effect of initial concentration on the explosion behavior of a stoichiometric CH4/O2/N2 mixture under air-combustion conditions was studied. Two mathematical models were used with the aim at simulating the gas explosion in the middle scale explosion vessel, and the associated effects of the temperature for different gas/air concentrations. Peak pressure, maximum rate of pressure rise and laminar burning velocity were measured from pressure time records of explosions occurring in a 1 m3 closed cylindrical vessel. The results of the models were validated considering a set of data (pressure time histories and root mean square velocity). The obtained results are relevant to the practice of gas explosion testing and the interpretation of test results and, they should be taken as the input data for CFD simulation to improve the conditions for standard tests.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-02-01

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

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

    International Nuclear Information System (INIS)

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

  8. Simulating thermal explosion of RDX-based explosives: Model comparison with experiment

    Energy Technology Data Exchange (ETDEWEB)

    Yoh, J J; McClelland, M A; Maienschein, J L; Wardell, J F; Tarver, C M

    2004-10-11

    We compare two-dimensional model results with measurements for the thermal, chemical and mechanical behavior in a thermal explosion experiment. Confined high explosives are heated at a rate of 1 C per hour until an explosion is observed. The heating, ignition, and deflagration phases are modeled using an Arbitrarily Lagrangian-Eulerian code (ALE3D) that can handle a wide range of time scales that vary from a structural to a dynamic hydro time scale. During the pre-ignition phase, quasi-static mechanics and diffusive thermal transfer from a heat source to the HE are coupled with the finite chemical reactions that include both endothermic and exothermic processes. Once the HE ignites, a hydro dynamic calculation is performed as a burn front propagates through the HE. Two RDX-based explosives, C-4 and PBXN-109, are considered, whose chemical-thermal-mechanical models are constructed based on measurements of thermal and mechanical properties along with small scale thermal explosion measurements. The simulated dynamic response of HE confinement during the explosive phase is compared to measurements in large scale thermal explosion tests. The explosion temperatures for both HE's are predicted to within 5 C. Calculated and measured wall strains provide an indication of vessel pressurization during the heating phase and violence during the explosive phase. During the heating phase, simulated wall strains provide only an approximate representation of measured values indicating a better numerical treatment is needed to provide accurate results. The results also show that more numerical accuracy is needed for vessels with lesser confinement strength. For PBXN-109, the measured wall strains during the explosion are well represented by the ALE3D calculations.

  9. ASEAN+3 Bond Market Guides

    OpenAIRE

    Asian Development Bank (ADB)

    2012-01-01

    The ASEAN+3 Bond Market Guide contains the comprehensive reports of the ASEAN+3 Bond Market Forum Sub-Forum 1 (SF1) and Sub-Forum 2 (SF2). The SF1 report (Volume 1) analyzes the harmonization and standardization of the existing bond markets in the ASEAN+3. It also contains the individual market guides of 11 economies under the ASEAN+3 Bond Market Forum (ABMF). The SF2 report (Volume 2) provides an overview of the ASEAN+3 bond markets and their infrastructures, as well as issues confronted by ...

  10. Optimal Investment in Structured Bonds

    DEFF Research Database (Denmark)

    Jessen, Pernille; Jørgensen, Peter Løchte

    The paper examines the role of structured bonds in the optimal portfolio of a small retail investor. We consider the typical structured bond essentially repacking an exotic option and a zero coupon bond, i.e. an investment with portfolio insurance. The optimal portfolio is found when the investment...... opportunities consist of a risky reference fund, a risk-free asset and a structured bond. Key model elements are the trading strategy and utility function of the investor. Our numerical results indicate structured bonds do have basis for consideration in the optimal portfolio. The product holdings...

  11. Hydrogen bonding in ionic liquids.

    Science.gov (United States)

    Hunt, Patricia A; Ashworth, Claire R; Matthews, Richard P

    2015-03-01

    Ionic liquids (IL) and hydrogen bonding (H-bonding) are two diverse fields for which there is a developing recognition of significant overlap. Doubly ionic H-bonds occur when a H-bond forms between a cation and anion, and are a key feature of ILs. Doubly ionic H-bonds represent a wide area of H-bonding which has yet to be fully recognised, characterised or explored. H-bonds in ILs (both protic and aprotic) are bifurcated and chelating, and unlike many molecular liquids a significant variety of distinct H-bonds are formed between different types and numbers of donor and acceptor sites within a given IL. Traditional more neutral H-bonds can also be formed in functionalised ILs, adding a further level of complexity. Ab initio computed parameters; association energies, partial charges, density descriptors as encompassed by the QTAIM methodology (ρBCP), qualitative molecular orbital theory and NBO analysis provide established and robust mechanisms for understanding and interpreting traditional neutral and ionic H-bonds. In this review the applicability and extension of these parameters to describe and quantify the doubly ionic H-bond has been explored. Estimating the H-bonding energy is difficult because at a fundamental level the H-bond and ionic interaction are coupled. The NBO and QTAIM methodologies, unlike the total energy, are local descriptors and therefore can be used to directly compare neutral, ionic and doubly ionic H-bonds. The charged nature of the ions influences the ionic characteristics of the H-bond and vice versa, in addition the close association of the ions leads to enhanced orbital overlap and covalent contributions. The charge on the ions raises the energy of the Ylp and lowers the energy of the X-H σ* NBOs resulting in greater charge transfer, strengthening the H-bond. Using this range of parameters and comparing doubly ionic H-bonds to more traditional neutral and ionic H-bonds it is clear that doubly ionic H-bonds cover the full range of weak

  12. Contained fission explosion breeder reactor system

    International Nuclear Information System (INIS)

    A reactor system for producing useful thermal energy and valuable isotopes, such as plutonium-239, uranium-233, and/or tritium, in which a pair of sub-critical masses of fissile and fertile actinide slugs are propelled into an ellipsoidal pressure vessel. The propelled slugs intercept near the center of the chamber where the concurring slugs become a more than prompt configuration thereby producing a fission explosion. Re-useable accelerating mechanisms are provided external of the vessel for propelling the slugs at predetermined time intervals into the vessel. A working fluid of lean molten metal slurry is injected into the chamber prior to each explosion for the attenuation of the explosion's effects, for the protection of the chamber's walls, and for the absorbtion of thermal energy and debris from the explosion. The working fluid is injected into the chamber in a pattern so as not to interfere with the flight paths of the slugs and to maximize the concentration of working fluid near the chamber's center. The heated working fluid is drained from the vessel and is used to perform useful work. Most of the debris from the explosion is collected as precipitate and is used for the manufacture of new slugs

  13. Electrostatic sensitivity of secondary high explosives

    Energy Technology Data Exchange (ETDEWEB)

    Campos, C.A.

    1980-06-01

    An Electrostatic Sensitivity Test System designed at Pantex was used to evaluate the secondary high explosives PETN, HMX, RDX, HNS I, HNS II and TATB. The purpose of this study was to establish test conditions for a standard electrostatic sensitivity test and measure baseline data of a few secondary explosives. Although secondary explosives are often considered quite insensitive to an electrostatic discharge, PETN, HMX, and RDX were initiated. Several external elements to the high explosive were found to have an influence on sensitivity. Initiation appeared to be dependent on the nature of the discharge current curve. Those elements recognized as having a significant effect on the results were held constant in this study. These included: distance between discharge plates; sample moisture content; material density; and system resistance, capacitance and inductance. However, no attempt was made in this study to determine the extent to which the high explosive response to electrostatic discharge is affected by these factors since such correlation is not necessary to determine relative sensitivities.

  14. Canine detection odor signatures for explosives

    Science.gov (United States)

    Williams, Marc; Johnston, J. M.; Cicoria, Matt; Paletz, E.; Waggoner, L. Paul; Edge, Cindy C.; Hallowell, Susan F.

    1998-12-01

    Dogs are capable of detecting and discriminating a number of compounds constituting a complex odor. However, they use only a few of these to recognize a substance. The focus of this research is to determine the compounds dogs learn to use in recognizing explosives. This is accomplished by training dogs under behavioral laboratory conditions to respond differentially on separate levers to 1) blank air, 2) a target odor, such as an explosive, and 3) all other odors (non-target odors). Vapor samples are generated by a serial dilution vapor generator whose operation and output is characterized by GC/MS. Once dogs learn this three-lever discrimination, testing sessions are conducted containing a number of probe trials in which vapor from constituent compounds of the target is presented. Which lever the dogs respond to on these probe trials indicates whether they can smell the compound at all (blank lever) or whether it smells like toe target odor (e.g., the explosive) or like something else. This method was conducted using TNT, C-4, and commercial dynamite. The data show the dogs' reactions to each of the constituent compounds tested for each explosive. Analysis of these data reveal the canine detection odor signature for these explosives.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-06-05

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

  16. Additional disulfide bonds in insulin

    DEFF Research Database (Denmark)

    Vinther, Tine N; Pettersson, Ingrid; Huus, Kasper;

    2015-01-01

    The structure of insulin, a glucose homeostasis-controlling hormone, is highly conserved in all vertebrates and stabilized by three disulfide bonds. Recently, we designed a novel insulin analogue containing a fourth disulfide bond located between positions A10-B4. The N-terminus of insulin's B......-chain is flexible and can adapt multiple conformations. We examined how well disulfide bond predictions algorithms could identify disulfide bonds in this region of insulin. In order to identify stable insulin analogues with additional disulfide bonds, which could be expressed, the Cβ cut-off distance had...... in comparison to analogues with additional disulfide bonds that were more difficult to predict. In contrast, addition of the fourth disulfide bond rendered all analogues resistant to fibrillation under stress conditions and all stable analogues bound to the insulin receptor with picomolar affinities. Thus...

  17. Study on electrical conductivity and phase transition in singly doped BIPBVOX (Bi2V1-xPbxO5.5-x/2) solid electrolyte

    Science.gov (United States)

    Beg, Saba; Naqvi, Faria K.; Al-Areqi, Niyazi A. S.

    2014-12-01

    Samples of bismuth lead vanadium oxide (BIPBVOX) (Bi2V1-xPbxO5.5-x/2) singly substituted system in the composition range 0.05 ≤ x ≤ 0.20 were prepared by sol-gel synthesis route. Structural investigations were carried out by using a combination of differential thermal analysis (DTA) and powder X-ray diffraction (PXRD) technique. Energy dispersive X-ray spectroscopy analysis (EDXA) of doped samples was carried out to predict the sample purity and doping concentration. Transitions, α↔β, β↔γ and γ‧↔γ were detected by XRD, DTA and variation in the Arrhenius plots of conductivity. The ionic conductivity was measured by AC impedance spectroscopy. The solid solutions with composition x ≤ 0.07 undergo α↔β phase transition, at 329 °C and β↔γ phase transition at 419 °C. The highly conducting γ‧-phase was effectively stabilized at room temperature for compositions with x ≥ 0.17 whose thermal stability increases with Pb content. At 300 °C, the highest value of conductivity 6.234 × 10-5 S cm-1 was obtained for composition x = 0.15 and at 600 °C the highest value of conductivity 0.65 S cm-1 is observed for x = 0.17. AC impedance plots reveal that the conductivity is mainly due to the grain contribution to oxide ion conductivity.

  18. CEH-20/Pbx and UNC-62/Meis function upstream of rnt-1/Runx to regulate asymmetric divisions of the C. elegans stem-like seam cells

    Directory of Open Access Journals (Sweden)

    Samantha Hughes

    2013-06-01

    Caenorhabditis elegans seam cells divide in the stem-like mode throughout larval development, with the ability to both self-renew and produce daughters that differentiate. Seam cells typically divide asymmetrically, giving rise to an anterior daughter that fuses with the hypodermis and a posterior daughter that proliferates further. Previously we have identified rnt-1 (a homologue of the mammalian cancer-associated stem cell regulator Runx as being an important regulator of seam development, acting to promote proliferation; rnt-1 mutants have fewer seam cells whereas overexpressing rnt-1 causes seam cell hyperplasia. We isolated the interacting CEH-20/Pbx and UNC-62/Meis TALE-class transcription factors during a genome-wide RNAi screen for novel regulators of seam cell number. Animals lacking wild type CEH-20 or UNC-62 display seam cell hyperplasia, largely restricted to the anterior of the worm, whereas double mutants have many additional seam cells along the length of the animal. The cellular basis of the hyperplasia involves the symmetrisation of normally asymmetric seam cell divisions towards the proliferative stem-like fate. The hyperplasia is completely suppressed in rnt-1 mutants, and rnt-1 is upregulated in ceh-20 and unc-62 mutants, suggesting that CEH-20 and UNC-62 function upstream of rnt-1 to limit proliferative potential to the appropriate daughter cell. In further support of this we find that CEH-20 is asymmetrically localised in seam daughters following an asymmetric division, being predominantly restricted to anterior nuclei whose fate is to differentiate. Thus, ceh-20 and unc-62 encode crucial regulators of seam cell division asymmetry, acting via rnt-1 to regulate the balance between proliferation and differentiation.

  19. Experiment Study on the Apparent Viscosity of Cast PBX%浇注PBX药浆表观黏度的实验研究∗

    Institute of Scientific and Technical Information of China (English)

    孙利杰; 常双君; 杨雪芹; 刘详

    2016-01-01

    以低相对分子质量端羟基聚丁二烯( HTPB)、己二酸二辛脂( DOA)制备了HTPB粘结剂体系,再加入铝粉和不同粒径级配的硫酸钠颗粒制备浇注高聚物粘结炸药( PBX)药浆,然后采用不同的异氰酸酯固化剂进行固化。讨论了硫酸钠粗细粒径配比对浇注PBX药浆黏度的影响,以及不同固化剂对反应物黏度和固化时间的影响。结果表明,当粗细颗粒硫酸钠质量比为3∶1时,浇注PBX药浆黏度最低;异氰酸酯固化剂中加入少量MDI可以提高药浆固化速率,缩短固化时间。%Binder systems of hydroxyl⁃terminated polybutadiene( HTPB) with low molecular weights, dioctyla⁃dipate (DOA),aluminum powder and different particle size gradation sodium sulfate were prepared. The systems were cured with different curing agents. The influence of sodium sulfate gradation on the PBX slurry viscosity and the influence of curing agents on the viscosity and curing time of slurry were discussed. The results showed that, when the mass ratio of sodium sulfate was 3∶1, the viscosity of drug slurry was the lowest. The slurry curing rate and time were increased and shorten when a small amount of MDI was added into isocyanate curing agent.

  20. Local magnitudes of small contained explosions.

    Energy Technology Data Exchange (ETDEWEB)

    Chael, Eric Paul

    2009-12-01

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

  1. Criticality safety in high explosives dissolution

    Energy Technology Data Exchange (ETDEWEB)

    Troyer, S.D.

    1997-06-01

    In 1992, an incident occurred at the Pantex Plant in which the cladding around a fissile material component (pit) cracked during dismantlement of the high explosives portion of a nuclear weapon. Although the event did not result in any significant contamination or personnel exposures, concerns about the incident led to the conclusion that the current dismantlement process was unacceptable. Options considered for redesign, dissolution tooling design considerations, dissolution tooling design features, and the analysis of the new dissolution tooling are summarized. The final tooling design developed incorporated a number of safety features and provides a simple, self-contained, low-maintenance method of high explosives removal for nuclear explosive dismantlement. Analyses demonstrate that the tooling design will remain subcritical under normal, abnormal, and credible accident scenarios. 1 fig.

  2. Criticality safety in high explosives dissolution

    International Nuclear Information System (INIS)

    In 1992, an incident occurred at the Pantex Plant in which the cladding around a fissile material component (pit) cracked during dismantlement of the high explosives portion of a nuclear weapon. Although the event did not result in any significant contamination or personnel exposures, concerns about the incident led to the conclusion that the current dismantlement process was unacceptable. Options considered for redesign, dissolution tooling design considerations, dissolution tooling design features, and the analysis of the new dissolution tooling are summarized. The final tooling design developed incorporated a number of safety features and provides a simple, self-contained, low-maintenance method of high explosives removal for nuclear explosive dismantlement. Analyses demonstrate that the tooling design will remain subcritical under normal, abnormal, and credible accident scenarios. 1 fig

  3. Securing Infrastructure from High Explosive Threats

    Energy Technology Data Exchange (ETDEWEB)

    Glascoe, L; Noble, C; Reynolds, J; Kuhl, A; Morris, J

    2009-03-20

    Lawrence Livermore National Laboratory (LLNL) is working with the Department of Homeland Security's Science and Technology Directorate, the Transportation Security Administration, and several infrastructure partners to characterize and help mitigate principal structural vulnerabilities to explosive threats. Given the importance of infrastructure to the nation's security and economy, there is a clear need for applied research and analyses (1) to improve understanding of the vulnerabilities of these systems to explosive threats and (2) to provide decision makers with time-critical technical assistance concerning countermeasure and mitigation options. Fully-coupled high performance calculations of structural response to ideal and non-ideal explosives help bound and quantify specific critical vulnerabilities, and help identify possible corrective schemes. Experimental validation of modeling approaches and methodologies builds confidence in the prediction, while advanced stochastic techniques allow for optimal use of scarce computational resources to efficiently provide infrastructure owners and decision makers with timely analyses.

  4. Road Foundation Improvement by Explosive Force

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A highway was constructed in Jiangxi Province, China, through mountainous area. Some sections of the highway went through valleys where a soft clay layer of 6-8.5 m deep was encountered. A new explosive method was developed and adopted for this project. In this method, blasting is used to remove and replace soft clay with crushed stones. Explosive charges are placed in the soil to be improved according to a certain pattern. Crushed stones are piled up behind the area where charges are installed. The explosion removes most of the soil in the exploded area and causes the pile of crushed stones to slide into the area where the soil is removed by blasting. A formular was suggested to calculate the charge weight used for improving a certain type of soil. The effectiveness of the method is evaluated using borehole exploration, plate load tests,and ground-probing radar tests.

  5. Probing thermonuclear supernova explosions with neutrinos

    CERN Document Server

    Odrzywolek, A

    2010-01-01

    Aims: We present for the first time neutrino light curves and energy spectra for two representative Type Ia supernova explosion models: a pure deflagration and a delayed detonation model. Methods: Weak neutrino flux is calculated using NSE abundances convoluted with the approximate neutrino spectra of the individual nuclei. Thermal neutrino spectrum (pair+plasma) is calculated using PSNS code. Results: The two competing explosion scenarios, while producing almost identical electromagnetic output are shown to be completely different in neutrinos. We identified the following main contributors to the neutrino signal: (1) weak electron neutrino emission from electron captures (in particular on protons, Co55, and Ni56), and numerous beta-active nuclei produced by the thermonuclear flame and/or detonation front, (2) electron antineutrinos from positron captures on neutrons, and (3) the thermal emission from pair annihilation. We estimate that a pure deflagration supernova explosion at a distance of 1 kpc would trig...

  6. A new formal perspective on 'Cambrian explosions'.

    Science.gov (United States)

    Wallace, Rodrick

    2014-01-01

    The 'Cambrian explosion' 500 Myr ago saw a relatively sudden proliferation of organism Bauplan and ecosystem niche structure that continues to haunt evolutionary biology. Here, adapting standard methods from information theory and statistical mechanics, we model the phenomenon as a noise-driven phase transition, in the context of deep-time relaxation of current path-dependent evolutionary constraints. The result is analogous to recent suggestions that multiple 'explosions' of increasing complexity in the genetic code were driven by rising intensities of available metabolic free energy. In the absence of severe path-dependent lock-in, 'Cambrian explosions' are standard features of blind evolutionary process, representing outliers in the ongoing routine of evolutionary punctuated equilibrium. PMID:24439546

  7. Mechanical Model of Domestic Gas Explosion Load

    Institute of Scientific and Technical Information of China (English)

    HAN Yongli; CHEN Longzhu

    2008-01-01

    With the increase of domestic gas consumption in cities and towns in China, gas explosion accidents happened rather frequently, and many structures were damaged greatly.Rational physical design could protect structures from being destroyed, but the character of explosion load must be learned firstly by establishing a correct mechanical model to simulate vented gas explosions.The explosion process has been studied for many years towards the safety of chemical industry equipments.The key problem of these studies was the equations usually involved some adjustable parameters that must be evaluated by experimental data, and the procedure of calculation was extremely complicated, so the reliability of these studies was seriously limited.Based on these studies, a simple mathematical model was established in this paper by using energy conservation,mass conservation, gas state equation, adiabatic compression equation and gas venting equation.Explosion load must be estimated by considering the room layout; the rate of pressure rise was then corrected by using a turbulence factor, so the pressure-time curve could be obtained.By using this method, complicated calculation was avoided, while experimental and calculated results fitted fairly well.Some pressure-time curves in a typical rectangular room were calculated to investigate the influences of different ignition locations, gas thickness, concentration, room size and venting area on the explosion pressure.The results indicated that: it was the most dangerous condition when being ignited in the geometry centre of the room; the greater the burning velocity, the worse the venting effect; the larger the venting pressure, the higher the peak pressure; the larger the venting area, the lower the peak pressure.

  8. Explosive fragmentation of liquids in spherical geometry

    Science.gov (United States)

    Milne, A.; Longbottom, A.; Frost, D. L.; Loiseau, J.; Goroshin, S.; Petel, O.

    2016-07-01

    Rapid acceleration of a spherical shell of liquid following central detonation of a high explosive causes the liquid to form fine jets that are similar in appearance to the particle jets that are formed during explosive dispersal of a packed layer of solid particles. Of particular interest is determining the dependence of the scale of the jet-like structures on the physical parameters of the system, including the fluid properties (e.g., density, viscosity, and surface tension) and the ratio of the mass of the liquid to that of the explosive. The present paper presents computational results from a multi-material hydrocode describing the dynamics of the explosive dispersal process. The computations are used to track the overall features of the early stages of dispersal of the liquid layer, including the wave dynamics, and motion of the spall and accretion layers. The results are compared with new experimental results of spherical charges surrounded by a variety of different fluids, including water, glycerol, ethanol, and vegetable oil, which together encompass a significant range of fluid properties. The results show that the number of jet structures is not sensitive to the fluid properties, but primarily dependent on the mass ratio. Above a certain mass ratio of liquid fill-to-explosive burster (F / B), the number of jets is approximately constant and consistent with an empirical model based on the maximum thickness of the accretion layer. For small values of F / B, the number of liquid jets is reduced, in contrast with explosive powder dispersal, where small F / B yields a larger number of particle jets. A hypothetical explanation of these features based on the nucleation of cavitation is explored numerically.

  9. 无铅或少铅钙钛矿CH3NH3M1-xPbxX3(M=Sn,Sr;X=Cl,Br,I)太阳能电池的研究进展%Research Development of Lead-free or Less-lead Perovskite CH3NH3M1-xPbxX3 (M =Sn, Sr and X =Cl, Br, I) Solar Cells

    Institute of Scientific and Technical Information of China (English)

    邸学倩; 杨秋华; 安宏乐

    2015-01-01

    本文综述了Sn2+或Sr2+取代的无铅或少铅钙钛矿CH3NH3PbX3 (X=Cl,Br,I)的结构及其主要的制备方法,评述了各种方法的优缺点.简要介绍了无铅或少铅钙钛矿材料的能隙以及材料的稳定性对太阳能电池的影响,并对其发展前景进行了展望.

  10. Welding of titanium and nickel alloy by combination of explosive welding and spark plasma sintering technologies

    Energy Technology Data Exchange (ETDEWEB)

    Malyutina, Yu. N., E-mail: iuliiamaliutina@gmail.com; Bataev, A. A., E-mail: bataev@adm.nstu.ru; Shevtsova, L. I., E-mail: edeliya2010@mail.ru [Novosibirsk State Technical University, Novosibirsk, 630073 (Russian Federation); Mali, V. I., E-mail: vmali@mail.ru; Anisimov, A. G., E-mail: anis@hydro.nsc.ru [Lavrentyev Institute of Hydrodynamics SB RAS, Novosibirsk, 630090 (Russian Federation)

    2015-10-27

    A possibility of titanium and nickel-based alloys composite materials formation using combination of explosive welding and spark plasma sintering technologies was demonstrated in the current research. An employment of interlayer consisting of copper and tantalum thin plates makes possible to eliminate a contact between metallurgical incompatible titanium and nickel that are susceptible to intermetallic compounds formation during their interaction. By the following spark plasma sintering process the bonding has been received between titanium and titanium alloy VT20 through the thin powder layer of pure titanium that is distinguished by low defectiveness and fine dispersive structure.

  11. Welding of titanium and nickel alloy by combination of explosive welding and spark plasma sintering technologies

    International Nuclear Information System (INIS)

    A possibility of titanium and nickel-based alloys composite materials formation using combination of explosive welding and spark plasma sintering technologies was demonstrated in the current research. An employment of interlayer consisting of copper and tantalum thin plates makes possible to eliminate a contact between metallurgical incompatible titanium and nickel that are susceptible to intermetallic compounds formation during their interaction. By the following spark plasma sintering process the bonding has been received between titanium and titanium alloy VT20 through the thin powder layer of pure titanium that is distinguished by low defectiveness and fine dispersive structure

  12. Microstructure and wear resistance of electro-thermal explosion sprayed stellite coating used for remanufacturing

    Institute of Scientific and Technical Information of China (English)

    JIN Guo; XU Bin-shi; WANG Hai-dou; LI Qing-fen; WEI Shi-cheng

    2005-01-01

    Electro-thermal explosion directional spraying was used to prepare the stellite coating on substrate of the AISI 1045 steel. The morphologies of cross-section and worn scar, porosity, distribution of elements, microhardness and wear resistance of the coating were determined by means of SEM, EDAX, micro-hardness tester and sliding wear tester. Because of the compact construction, good bonding and high hardness, the coating is characterized by good wear resistance. The results show that the mainly failure mode of the stellite coating is microplowing.

  13. CHOSEN PROPERTIES OF SANDWICH MATERIAL Ti-304 STAINLESS STEEL AFTER EXPLOSIVE WELDING

    Directory of Open Access Journals (Sweden)

    Dmytro Ostroushko

    2011-05-01

    Full Text Available The work deals with evaluation of joint of stainless steel 304 SS (sheet and commercially pure Ti both after welding explosion and followed-up annealing at 600°C/1.5h/air. The bonding line shows sinusoidal character with curls in crest unlike the trough of the sine curve. The heat treatment does not change the character of the interface. In work amplitude, wave length and the interface thickness were measured. Thickness of compressed cladded matrix of Ti was measured in area of crests and troughs. In crest of joint melted zones were studied, where complex oxides and intermetallic phases were revealed.

  14. Predicting Heats of Explosion of Nitroaromatic Compounds through NBO Charges and 15N NMR Chemical Shifts of Nitro Groups

    Directory of Open Access Journals (Sweden)

    Ricardo Infante-Castillo

    2012-01-01

    Full Text Available This work presents a new quantitative model to predict the heat of explosion of nitroaromatic compounds using the natural bond orbital (NBO charge and 15N NMR chemical shifts of the nitro groups (15NNitro as structural parameters. The values of the heat of explosion predicted for 21 nitroaromatic compounds using the model described here were compared with experimental data. The prediction ability of the model was assessed by the leave-one-out cross-validation method. The cross-validation results show that the model is significant and stable and that the predicted accuracy is within 0.146 MJ kg−1, with an overall root mean squared error of prediction (RMSEP below 0.183 MJ kg−1. Strong correlations were observed between the heat of explosion and the charges (R2 = 0.9533 and 15N NMR chemical shifts (R2 = 0.9531 of the studied compounds. In addition, the dependence of the heat of explosion on the presence of activating or deactivating groups of nitroaromatic explosives was analyzed. All calculations, including optimizations, NBO charges, and 15NNitro NMR chemical shifts analyses, were performed using density functional theory (DFT and a 6-311+G(2d,p basis set. Based on these results, this practical quantitative model can be used as a tool in the design and development of highly energetic materials (HEM based on nitroaromatic compounds.

  15. Long-lived explosive volcanism on Mercury

    OpenAIRE

    Thomas, Rebecca J.; Rothery, David A.; Conway, Susan J.; Anand, Mahesh

    2014-01-01

    The duration and timing of volcanic activity on Mercury are key indicators of the thermal evolution of the planet and provide a valuable comparative example for other terrestrial bodies. The majority of effusive volcanism on Mercury appears to have occurred early in the planet's geological history (~4.1–3.55 Ga), but there is also evidence for explosive volcanism. Here we present evidence that explosive volcanism occurred from at least 3.9 Ga until less than a billion years ago and so was sub...

  16. Expansion of Metallic Cylinders under Explosive Loading

    Directory of Open Access Journals (Sweden)

    M.S. Bola

    1992-07-01

    Full Text Available The behaviour of expanding metallic cylinders under explosive loading was studied. Using ultra high speed photography, the expansion characteristics of aluminium and copper metallic cylinders have been evaluated with different c/m ratio, and by changing the nature of high explosive. The results obtained are comparable to those predicted by the Gurney's energy and momentum balance equations. A cylinder test has been established for comparative to the metal by octol, TNT, PEK-1, baratol and composition B are calculated. The results are in close agreement with those calculated by Kury et al.

  17. Biodegradation of the Nitramine Explosive CL-20

    OpenAIRE

    Trott, Sandra; Nishino, Shirley F.; Hawari, Jalal; Spain, Jim C.

    2003-01-01

    The cyclic nitramine explosive CL-20 (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane) was examined in soil microcosms to determine whether it is biodegradable. CL-20 was incubated with a variety of soils. The explosive disappeared in all microcosms except the controls in which microbial activity had been inhibited. CL-20 was degraded most rapidly in garden soil. After 2 days of incubation, about 80% of the initial CL-20 had disappeared. A CL-20-degrading bacterial strain, Agrobact...

  18. THEORIES OF ROCK BREAKAGE WITH EXPLOSIVES

    Directory of Open Access Journals (Sweden)

    Vinko Škrlec

    2014-12-01

    Full Text Available The prediction and observation of the nature and dimensions of damaged zones in the surrounding rock mass and understanding the mechanisms of fracturing and crushing of the rock mass with explosives is one of the most important parameters in blasting design in order to obtain preferred granulation and reduce damaging effects of blasting on the environment. An overview of existing rock breakage theories with the energy released by the detonation of explosives is given in this paper (the paper is published in Croatian.

  19. Statistical Hot Spot Model for Explosive Detonation

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, III, A L

    2005-07-14

    The Non-local Thermodynamic Equilibrium Statistical Hot Spot Model (NLTE SHS), a new model for explosive detonation, is described. In this model, the formation, ignition, propagation, and extinction of hot spots is explicitly modeled. The equation of state of the explosive mixture is treated with a non-local equilibrium thermodynamic assumption. A methodology for developing the parameters for the model is discussed, and applied to the detonation velocity diameter effect. Examination of these results indicates where future improvements to the model can be made.

  20. Statistical Hot Spot Model for Explosive Detonation

    Energy Technology Data Exchange (ETDEWEB)

    Nichols III, A L

    2004-05-10

    The Non-local Thermodynamic Equilibrium Statistical Hot Spot Model (NLTE SHS), a new model for explosive detonation, is described. In this model, the formation, ignition, propagation, and extinction of hot spots is explicitly modeled. The equation of state of the explosive mixture is treated with a nonlocal equilibrium thermodynamic assumption. A methodology for developing the parameters for the model is discussed, and applied to the detonation velocity diameter effect. Examination of these results indicates where future improvements to the model can be made.

  1. Spherical Solutions of an Underwater Explosion Bubble

    Directory of Open Access Journals (Sweden)

    Andrew B. Wardlaw

    1998-01-01

    Full Text Available The evolution of the 1D explosion bubble flow field out to the first bubble minimum is examined in detail using four different models. The most detailed is based on the Euler equations and accounts for the internal bubble fluid motion, while the simplest links a potential water solution to a stationary, Isentropic bubble model. Comparison of the different models with experimental data provides insight into the influence of compressibility and internal bubble dynamics on the behavior of the explosion bubble.

  2. Micromechanics-based prediction of thermoelastic properties of high energy materials

    CERN Document Server

    Banerjee, Biswajit

    2012-01-01

    High energy materials such as polymer bonded explosives are commonly used as propellants. These particulate composites contain explosive crystals suspended in a rubbery binder. However, the explosive nature of these materials limits the determination of their mechanical properties by experimental means. Therefore micromechanics-based methods for the determination of the effective thermoelastic properties of polymer bonded explosives are investigated in this research. Polymer bonded explosives are two-component particulate composites with high volume fractions of particles (volume fraction $>$ 90%) and high modulus contrast (ratio of Young's modulus of particles to binder of 5,000-10,000). Experimentally determined elastic moduli of one such material, PBX 9501, are used to validate the micromechanics methods examined in this research. The literature on micromechanics is reviewed; rigorous bounds on effective elastic properties and analytical methods for determining effective properties are investigated in the ...

  3. Credit default swaps, bond spreads and the bond market

    OpenAIRE

    Zhu, Meicheng

    2014-01-01

    With the rapid development of the credit default swap (CDS) market, the issue of how the introduction of CDSs affects the corporate bond market has been of particular interest to researchers and policy makers. This has been investigated in the literature from two perspectives. One is to examine the relationship between the CDS and the bond markets in price discovery, and the other is concerned with researching the CDS trading effects on bond spreads. Referring to the former approach, most rel...

  4. Solder extrusion pressure bonding process and bonded products produced thereby

    Science.gov (United States)

    Beavis, Leonard C.; Karnowsky, Maurice M.; Yost, Frederick G.

    1992-01-01

    Production of soldered joints which are highly reliable and capable of surviving 10,000 thermal cycles between about -40.degree. C. and 110.degree. C. Process involves interposing a thin layer of a metal solder composition between the metal surfaces of members to be bonded and applying heat and up to about 1000 psi compression pressure to the superposed members, in the presence of a reducing atmosphere, to extrude the major amount of the solder composition, contaminants including fluxing gases and air, from between the members being bonded, to form a very thin, strong intermetallic bonding layer having a thermal expansion tolerant with that of the bonded members.

  5. Avoiding silicon/glass bonding damage with fusion bonding method

    Institute of Scientific and Technical Information of China (English)

    Daohong Yang(杨道虹); Chen Xu(徐晨); Guangdi Shen(沈光地)

    2004-01-01

    A novel fusion bonding method between silicon and glass with Nd:YAG laser is described.This method overcomes the movable mechanical parts damage caused by the electrostatics force in micro-electronic machine-system(MEMS)device during the anodic bonding. The diameter of laser spot is 300 μm,the power of laser is 100 W,the laser velocity for bonding is 0.05 m/s,the average bonding tension is 6.3 MPa.It could distinctly reduce and eliminate the defects and damage,especially in movable sensitive mechanical parts of MEMS device.

  6. Solid state bonding of beryllium-copper for an ITER first wall application

    International Nuclear Information System (INIS)

    Several different joint assemblies were evaluated in support of a manufacturing technology for diffusion bonding a beryllium armor tile to a copper alloy heat sink for fusion reactor applications. Because beryllium reacts with all but a few elements to form intermetallic compounds, this study considered several different surface treatments as a means of both inhibiting these reactions and promoting a good diffusion bond between the two substrates. All diffusion bonded assemblies used aluminum or an aluminum-beryllium composite (AlBeMet-150) as the interfacial material in contact with beryllium. In most cases, explosive bonding was utilized as a technique for joining the copper alloy heat sink to an aluminum or AlBeMet-150 substrate, which was subsequently diffusion bonded to an aluminum coated beryllium tile. In this approach, a 250 μm thick titanium foil was used as a diffusion barrier between the copper and aluminum to prevent the formation of Cu-Al intermetallic phases. In all cases, a hot isostatic pressing (HIP) furnace was used in conjunction with canned assemblies in order to minimize oxidation and apply sufficient pressure on the assembly for excellent metal-to-metal contact and subsequent bonding. Several different processing schedules were evaluated during the course of this study; bonded assemblies were produced that failed outside the bond area indicating a 100% joint efficiency. (author)

  7. Solid state bonding of beryllium-copper for an ITER first wall application

    Energy Technology Data Exchange (ETDEWEB)

    Odegard, B.C. Jr.; Cadden, C.H. [Sandia National Labs., Livermore, CA (United States)

    1998-01-01

    Several different joint assemblies were evaluated in support of a manufacturing technology for diffusion bonding a beryllium armor tile to a copper alloy heat sink for fusion reactor applications. Because beryllium reacts with all but a few elements to form intermetallic compounds, this study considered several different surface treatments as a means of both inhibiting these reactions and promoting a good diffusion bond between the two substrates. All diffusion bonded assemblies used aluminum or an aluminum-beryllium composite (AlBeMet-150) as the interfacial material in contact with beryllium. In most cases, explosive bonding was utilized as a technique for joining the copper alloy heat sink to an aluminum or AlBeMet-150 substrate, which was subsequently diffusion bonded to an aluminum coated beryllium tile. In this approach, a 250 {mu}m thick titanium foil was used as a diffusion barrier between the copper and aluminum to prevent the formation of Cu-Al intermetallic phases. In all cases, a hot isostatic pressing (HIP) furnace was used in conjunction with canned assemblies in order to minimize oxidation and apply sufficient pressure on the assembly for excellent metal-to-metal contact and subsequent bonding. Several different processing schedules were evaluated during the course of this study; bonded assemblies were produced that failed outside the bond area indicating a 100% joint efficiency. (author)

  8. Horizontal dimensions of ionosphere agitation provoked by underground nuclear explosions

    International Nuclear Information System (INIS)

    The horizontal dimensions of ionosphere agitation provoked by underground nuclear explosions have been experimentally determined for 13 explosions conducted at the Balapan test site of the Semipalatinsk test site. (author)

  9. Supersymmetric Valence Bond Solid States

    OpenAIRE

    Arovas, Daniel P.; Hasebe, Kazuki; Qi, Xiao-Liang; Zhang, Shou-Cheng

    2009-01-01

    In this work we investigate the supersymmetric version of the valence bond solid (SVBS) state. In one dimension, the SVBS states continuously interpolate between the valence bond states for integer and half-integer spin chains, and they generally describe superconducting valence bond liquid states. Spin and superconducting correlation functions can be computed exactly for these states, and their correlation lengths are equal at the supersymmetric point. In higher dimensions, the wave function...

  10. Mezzanine finance and corporate bonds

    OpenAIRE

    Libena TETREVOVA

    2009-01-01

    The article deals with the problems of mezzanine finance in relation to corporate bonds. Firstly, attention is paid to definition of mezzanine finance. The term mezzanine finance is used as a term for hybrid forms of financing that combine elements of debt and equity financing. Mezzanine finance represents an alternative form of financing corporate activities. Secondly, possible forms of mezzanine finance are characterized. We can say that special types of corporate bonds (convertible bonds a...

  11. Hydrogen Bonds Involving Metal Centers

    OpenAIRE

    Pavlović, G.; Raos, N.

    2006-01-01

    Hydrogen bonds involving metal center as a hydrogen donor or hydrogen acceptor are only a specific type of metal-hydrogen interactions; it is therefore not easy to differentiate hydrogen bond from other metal-hydrogen interactions, especially agostic ones. The first part of the review is therefore devoted to the results of structural chemistry and molecular spectroscopy (NMR, IR), as a tool for differentiating hydrogen bondings from other hydrogen interactions. The classical examples of Pt···...

  12. Frequency of the ETV6-RUNX1, BCR-ABL1, TCF3-PBX1, and MLL-AFF1 fusion genes in Guatemalan pediatric acute lymphoblastic leukemia patients and their ethnic associations.

    Science.gov (United States)

    Carranza, Claudia; Granados, Lilian; Morales, Oneida; Jo, Wendy; Villagran, Swuanny; Tinti, Damaris; Villegas, Mauricio; Antillón, Federico; Torselli, Silvana; Silva, Gabriel

    2013-06-01

    Fusion genes involved in acute lymphoblastic leukemia (ALL) occur mostly due to genetic and environmental factors, and only a limited number of studies have reported any ethnic influence. This study assesses whether an ethnic influence has an effect on the frequency of any of the four fusion genes: BCR-ABL1, ETV6-RUNX1, TCF3-PBX1, and MLL-AFF1 found in ALL. To study this ethnic influence, mononuclear cells were obtained from bone marrow samples from 143 patients with ALL. We performed RNA extraction and reverse transcription, then assessed the quality of the cDNA by amplifying the ABL1 control gene, and finally evaluated the presence of the four transcripts by multiplex polymerase chain reaction. We found 10 patients who had the BCR-ABL1 fusion gene (7%); 3 patients (2%) were TCF3-PBX1 positive; and 6 patients (4.5%) were ETV6-RUNX1 positive. The incidence of this last fusion gene is quite low when compared to the values reported in most countries. The low incidence of the ETV6-RUNX1 fusion gene found in Guatemala matches the incidence rates that have been reported in Spain and Indian Romani. Since it is known that an ethnic resemblance exists among these three populations, as shown by ancestral marker studies, the ALL data suggests an ethnic influence on the occurrence and frequency of this particular fusion gene.

  13. Explosion of Ultrahigh Pressure Minerals in Mantle

    Institute of Scientific and Technical Information of China (English)

    BAI Wenji; YANG Jingsui; FANG Qingsong; YAN Binggang; ZHANG Zhongming

    2001-01-01

    @@ The microexplosion stucture of ultrahigh pressure minerals was found for the first time in podform chromitites within the mantle peridotite facies of Luobusa ophiolite along the Yarlung Zangbo suture zone.The explosion stuctures of high-energy silicate inclusions are commonly seen in thin sections (see figure).

  14. Incremental Pressing Technique in Explosive Charge

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A pressing technique has become available that might be useful for compressing granular explosives. If the height-diameter ratio of the charge is unfavorable,the high quality charge can not be obtained with the common single-action pressing. This paper presents incremental pressing technique, which can obtain the charge with higher overall density and more uniform density.

  15. Underground nuclear explosions: tectonic utility and dangers.

    Science.gov (United States)

    Toksöz, M N; Kehrer, H H

    1971-07-16

    The tectonic strain energy released by several underground nuclear explosions has been calculated through an analysis of seismic surface waves. The proportionally great amount of energy released in certain events suggests the possible uses for, as well as the hazards of, underground testing.

  16. Differential thermal analysis microsystem for explosive detection

    DEFF Research Database (Denmark)

    Olsen, Jesper Kenneth; Greve, Anders; Senesac, L.;

    2011-01-01

    A micro differential thermal analysis (DTA) system is used for detection of trace explosive particles. The DTA system consists of two silicon micro chips with integrated heaters and temperature sensors. One chip is used for reference and one for the measurement sample. The sensor is constructed...

  17. Java: An Explosion on the Internet.

    Science.gov (United States)

    Read, Tim; Hall, Hazel

    Summer 1995 saw the release, with considerable media attention, of draft versions of Sun Microsystems' Java computer programming language and the HotJava browser. Java has been heralded as the latest "killer" technology in the Internet explosion. Sun Microsystems and numerous companies including Microsoft, IBM, and Netscape have agreed upon…

  18. Modeling Astrophysical Explosions with Sustained Exascale Computing

    CERN Document Server

    Zingale, M; Malone, C M; Timmes, F X

    2015-01-01

    Our understanding of stars and their fates is based on coupling observations to theoretical models. Unlike laboratory physicists, we cannot perform experiments on stars, but rather must patiently take what nature allows us to observe. Simulation offers a means of virtual experimentation, enabling a detailed understanding of the most violent ongoing explosions in the Universe---the deaths of stars.

  19. Explosives safety research in the Netherlands

    NARCIS (Netherlands)

    Voort, M.M. van der; Weerheijm, J.; Wees, R.M.M. van; Dongen. P. van

    2013-01-01

    The handling of explosives and ammunition introduces a safety risk for personnel and third parties. Accidents related to storage, transport and transhipment may result in severe injury and material damage. TNO has developed a number of tools to quantify the consequences and risks of accidental explo

  20. Ionospheric disturbances produced by powerful explosives

    Science.gov (United States)

    Nagorskii, P. M.; Tarashchuk, Yu. E.

    1992-09-01

    Results of a study of wave-like ionospheric disturbances initiated by powerful explosives are presented and analyzed. Three types of wave processes with differing physical natures which propagate in the upper atmosphere and ionosphere to distances of thousands of kilometers are distinguished. The effect of shock-acoustic waves on indirect short wave radio propagation is considered.

  1. Ionospheric disturbances produced by powerful explosives

    International Nuclear Information System (INIS)

    Results of a study of wave-like ionospheric disturbances initiated by powerful explosives are presented and analyzed. Three types of wave processes with differing physical natures which propagate in the upper atmosphere and ionosphere to distances of thousands of kilometers are distinguished. The effect of shock-acoustic waves on indirect short wave radio propagation is considered

  2. Multiphase Instabilities in Explosive Dispersal of Particles

    Science.gov (United States)

    Rollin, Bertrand; Ouellet, Frederick; Annamalai, Subramanian; Balachandar, S. ``Bala''

    2015-11-01

    Explosive dispersal of particles is a complex multiphase phenomenon that can be observed in volcanic eruptions or in engineering applications such as multiphase explosives. As the layer of particles moves outward at high speed, it undergoes complex interactions with the blast-wave structure following the reaction of the energetic material. Particularly in this work, we are interested in the multiphase flow instabilities related to Richmyer-Meshkov (RM) and Rayleigh-Taylor (RM) instabilities (in the gas phase and particulate phase), which take place as the particle layer disperses. These types of instabilities are known to depend on initial conditions for a relatively long time of their evolution. Using a Eulerian-Lagrangian approach, we study the growth of these instabilities and their dependence on initial conditions related to the particulate phase - namely, (i) particle size, (ii) initial distribution, and (iii) mass ratio (particles to explosive). Additional complexities associated with compaction of the layer of particles are avoided here by limiting the simulations to modest initial volume fraction of particles. A detailed analysis of the initial conditions and its effects on multiphase RM/RT-like instabilities in the context of an explosive dispersal of particles is presented. This work was supported by the U.S. Department of Energy, National Nuclear Security Administration, Advanced Simulation and Computing Program, as a Cooperative Agreement under the Predictive Science Academic Alliance Program, Contract No. DE-NA0002378.

  3. New Dark Matter Detector using Nanoscale Explosives

    CERN Document Server

    Lopez, Alejandro; Freese, Katherine; Kurdak, Cagliyan; Tarle, Gregory

    2014-01-01

    We present nanoscale explosives as a novel type of dark matter detector and study the ignition properties. When a Weakly Interacting Massive Particle WIMP from the Galactic Halo elastically scatters off of a nucleus in the detector, the small amount of energy deposited can trigger an explosion. For specificity, this paper focuses on a type of two-component explosive known as a nanothermite, consisting of a metal and an oxide in close proximity. When the two components interact they undergo a rapid exothermic reaction --- an explosion. As a specific example, we consider metal nanoparticles of 5 nm radius embedded in an oxide. One cell contains more than a few million nanoparticles, and a large number of cells adds up to a total of 1 kg detector mass. A WIMP interacts with a metal nucleus of the nanoparticles, depositing enough energy to initiate a reaction at the interface between the two layers. When one nanoparticle explodes it initiates a chain reaction throughout the cell. A number of possible thermite mat...

  4. RDX/Sylgard extrudable explosive development

    Energy Technology Data Exchange (ETDEWEB)

    Osborn, A.G.; Schmitz, G.T.; Stallings, T.L.; West, G.T.; Ashcraft, R.W.

    1977-10-01

    Formulation procedures for X-0208, an 80 percent RDX/20 percent Sylgard extrudable, have been developed. The extrudable explosive, made from a mixture of micronized RDX and Class E RDX, will sustain detonation in a 1.65 mm channel and can be mechanically extruded into ribbon-type configurations.

  5. Developments in vapour cloud explosion blast modeling

    NARCIS (Netherlands)

    Mercx, W.P.M.; Berg, A.C. van den; Hayhurst, C.J.; Robertson, N.J.; Moran, K.C.

    2000-01-01

    TNT Equivalency methods are widely used for vapour cloud explosion blast modeling. Presently, however, other types of models are available which do not have the fundamental objections TNT Equivalency models have. TNO Multi-Energy method is increasingly accepted as a more reasonable alternative to be

  6. Delta 2 Explosion Plume Analysis Report

    Science.gov (United States)

    Evans, Randolph J.

    2000-01-01

    A Delta II rocket exploded seconds after liftoff from Cape Canaveral Air Force Station (CCAFS) on 17 January 1997. The cloud produced by the explosion provided an opportunity to evaluate the models which are used to track potentially toxic dispersing plumes and clouds at CCAFS. The primary goal of this project was to conduct a case study of the dispersing cloud and the models used to predict the dispersion resulting from the explosion. The case study was conducted by comparing mesoscale and dispersion model results with available meteorological and plume observations. This study was funded by KSC under Applied Meteorology Unit (AMU) option hours. The models used in the study are part of the Eastern Range Dispersion Assessment System (ERDAS) and include the Regional Atmospheric Modeling System (RAMS), HYbrid Particle And Concentration Transport (HYPACT), and Rocket Exhaust Effluent Dispersion Model (REEDM). The primary observations used for explosion cloud verification of the study were from the National Weather Service's Weather Surveillance Radar 1988-Doppler (WSR-88D). Radar reflectivity measurements of the resulting cloud provided good estimates of the location and dimensions of the cloud over a four-hour period after the explosion. The results indicated that RAMS and HYPACT models performed reasonably well. Future upgrades to ERDAS are recommended.

  7. Magic nuclei at explosive dynamo activity

    Directory of Open Access Journals (Sweden)

    Kondratyev V. N.

    2016-01-01

    Full Text Available Explosive nucleosynthesis at conditions of magnetorotational instabilities is considered for iron group nuclides by employing arguments of nuclear statistical equilibrium. Effects of ultra-strong nuclear magnetization are demonstrated to enhance the portion of titanium product. The results are corroborated with an excess of 44Ti revealed from the Integral mission data.

  8. Phenomenology of atmospheric, submarine and underground explosions

    International Nuclear Information System (INIS)

    An atmospheric nuclear explosion, particularly at ground level or at low altitude, generates immediate radiation that is propagated via different modes of energy transfer, i.e.: electromagnetic waves, light and heat, mechanical effects. Late-stage phenomena, such as the formation and propagation of the cloud, follow on after these early effects. The whole range of different effects - including acoustic and seismic waves as well as the products contained in the cloud - can be detected at distances up to several hundred or several thousand km. When the nuclear source is submarine, a shock wave is generated due to the interaction with the medium. According to the depth of the source, a gas bubble is created which starts to pulsate. As a result of this effect, the acoustic signal is modulated and then propagated to great distances away from the source, thus enabling identification of the explosive phenomenon in the water column. In the case of underground explosions, it is possible to establish a complete description of the interaction with the medium. This comprises generation and propagation of the shock wave, creation of the cavity, zonation of explosion effects, vent collapse, etc. The influence of depth on crater formation, subsidence and decoupling is also discussed. (authors)

  9. Some properties of explosive mixtures containing peroxides

    International Nuclear Information System (INIS)

    This study concerns mixtures of triacetone triperoxide (3,3,6,6,9,9-hexamethyl-1,2,4,5,7,8-hexoxonane, TATP) and ammonium nitrate (AN) with added water (W), as the case may be, and dry mixtures of TATP with urea nitrate (UN). Relative performances (RP) of the mixtures and their individual components, relative to TNT, were determined by means of ballistic mortar. The detonation energies, E0, and detonation velocities, D, were calculated for the mixtures studied by means of the thermodynamic code CHEETAH. Relationships have been found and are discussed between the RP and the E0 values related to unit volume of gaseous products of detonation of these mixtures. These relationships together with those between RP and oxygen balance values of the mixtures studied indicate different types of participation of AN and UN in the explosive decomposition of the respective mixtures. Dry TATP/UN mixtures exhibit lower RP than analogous mixtures TATP/AN containing up to 25% of water. Depending on the water content, the TATP/AN mixtures possess higher detonability values than the ANFO explosives. A semi-logarithmic relationship between the D values and oxygen coefficients has been derived for all the mixtures studied at the charge density of 1000 kg m-3. Among the mixtures studied, this relationship distinguishes several samples of the type of 'tertiary explosives' as well as samples that approach 'high explosives' in their performances and detonation velocities

  10. Bond failure patterns in vivo.

    Science.gov (United States)

    Linklater, Rognvald A; Gordon, Peter H

    2003-05-01

    The aim of this study was to identify the presence and pattern of differences in bond failure between tooth types in vivo when bonding orthodontic brackets with the no-mix orthodontic composite adhesive Right-On. In vivo bond failure for a single operator was recorded for 108 consecutive patients undergoing fixed-appliance orthodontic treatment. The bond failure data were analyzed by survival analysis. Time to first failure or censorship was recorded for each bonded attachment. Overall failure in the sample matched previous clinical studies but conflicted with previous ex vivo bond strength data. Mandibular and posterior teeth had significantly higher rates of failure than did maxillary and anterior teeth. The type of attachment used had a significant effect on bond survival. The results of this study confirm that in vivo bond survival is not uniform for all teeth. Comparisons between the findings of this study and those of a previous ex vivo study by the same authors failed to validate ex vivo bond strength testing as clinically relevant.

  11. Wafer bonding applications and technology

    CERN Document Server

    Gösele, Ulrich

    2004-01-01

    During the past decade direct wafer bonding has developed into a mature materials integration technology. This book presents state-of-the-art reviews of the most important applications of wafer bonding written by experts from industry and academia. The topics include bonding-based fabrication methods of silicon-on-insulator, photonic crystals, VCSELs, SiGe-based FETs, MEMS together with hybrid integration and laser lift-off. The non-specialist will learn about the basics of wafer bonding and its various application areas, while the researcher in the field will find up-to-date information about this fast-moving area, including relevant patent information.

  12. Photoinduced hydrogen-bonding dynamics.

    Science.gov (United States)

    Chu, Tian-Shu; Xu, Jinmei

    2016-09-01

    Hydrogen bonding dynamics has received extensive research attention in recent years due to the significant advances in femtolaser spectroscopy experiments and quantum chemistry calculations. Usually, photoexcitation would cause changes in the hydrogen bonding formed through the interaction between hydrogen donor and acceptor molecules on their ground electronic states, and such transient strengthening or weakening of hydrogen bonding could be crucial for the photophysical transformations and the subsequent photochemical reactions that occurred on a time scale from tens of femtosecond to a few nanoseconds. In this article, we review the combined experimental and theoretical studies focusing on the ultrafast electronic and vibrational hydrogen bonding dynamics. Through these studies, new mechanisms and proposals and common rules have been put forward to advance our understanding of the hydrogen bondings dynamics in a variety of important photoinduced phenomena like photosynthesis, dual fluorescence emission, rotational reorientation, excited-state proton transfer and charge transfer processes, chemosensor fluorescence sensing, rearrangements of the hydrogen-bond network including forming and breaking hydrogen bond in water. Graphical Abstract We review the recent advances on exploring the photoinduced hydrogen bonding dynamics in solutions through a joint approach of laser spectroscopy and theoretical calculation. The reviewed studies have put forward a new mechanism, new proposal, and new rule for a variety of photoinduced phenomena such as photosynthesis, dual fluorescence emission, rotational reorientation, excited-state proton transfer and charge transfer, chemosensor fluorescence sensing, and rearrangements of the hydrogen-bond network in water. PMID:27491849

  13. Bond Growth under Temperature Gradient.

    Directory of Open Access Journals (Sweden)

    P.K. Satyawali

    1999-12-01

    Full Text Available Grain and bond growth for dry snow are determined by the distribution of temperature andtemperature gradient in the snow matrix. From the standpoint of particle approach and based oncubic packing structure, a bond growth model has been developed for TG metamorphism. The paper.highlights the importance of bond formation and its effect on snow viscosity and finally on the rateof settlement. This is very important for developing a numerical snow pack model if microstructureis considered to be a basic parameter. A few experiments have been carried out to validate bond formation under temperature gradient.

  14. A simplified indirect bonding technique

    Directory of Open Access Journals (Sweden)

    Radha Katiyar

    2014-01-01

    Full Text Available With the advent of lingual orthodontics, indirect bonding technique has become an integral part of practice. It involves placement of brackets initially on the models and then their transfer to teeth with the help of transfer trays. Problems encountered with current indirect bonding techniques used are (1 the possibility of adhesive flash remaining around the base of the brackets which requires removal (2 longer time required for the adhesive to gain enough bond strength for secure tray removal. The new simplified indirect bonding technique presented here overcomes both these problems.

  15. CFD simulation of vented explosion and turbulent flame propagation

    Directory of Open Access Journals (Sweden)

    Tulach Aleš

    2015-01-01

    Full Text Available Very rapid physical and chemical processes during the explosion require both quality and quantity of detection devices. CFD numerical simulations are suitable instruments for more detailed determination of explosion parameters. The paper deals with mathematical modelling of vented explosion and turbulent flame spread with use of ANSYS Fluent software. The paper is focused on verification of preciseness of calculations comparing calculated data with the results obtained in realised experiments in the explosion chamber.

  16. CFD simulation of vented explosion and turbulent flame propagation

    Science.gov (United States)

    Tulach, Aleš; Mynarz, Miroslav; Kozubková, Milada

    2015-05-01

    Very rapid physical and chemical processes during the explosion require both quality and quantity of detection devices. CFD numerical simulations are suitable instruments for more detailed determination of explosion parameters. The paper deals with mathematical modelling of vented explosion and turbulent flame spread with use of ANSYS Fluent software. The paper is focused on verification of preciseness of calculations comparing calculated data with the results obtained in realised experiments in the explosion chamber.

  17. Energetic nanocomposites for detonation initiation in high explosives without primary explosives

    Science.gov (United States)

    Comet, Marc; Martin, Cédric; Klaumünzer, Martin; Schnell, Fabien; Spitzer, Denis

    2015-12-01

    The mixing of aluminum nanoparticles with a metal containing oxidizer (here, WO3 or Bi2(SO4)3) gives reactive materials called nanothermites. In this research, nanothermites were combined with high explosive nanoparticles (RDX) to prepare energetic nanocomposites. These smart nanomaterials have higher performances and are much less hazardous than primary explosives. Their flame propagation velocity can be tuned from 0.2 to 3.5 km/s, through their explosive content. They were used to initiate the detonation of a high explosive, the pentaerythritol tetranitrate. The pyrotechnic transduction of combustion into detonation was achieved with short length systems (<2 cm) and small amounts of energetic nanocomposites (˜100 mg) in semi-confined systems.

  18. Structural, electronic and optical properties of well-known primary explosive: Mercury fulminate

    Science.gov (United States)

    Yedukondalu, N.; Vaitheeswaran, G.

    2015-11-01

    Mercury Fulminate (MF) is one of the well-known primary explosives since 17th century and it has rendered invaluable service over many years. However, the correct molecular and crystal structures are determined recently after 300 years of its discovery. In the present study, we report pressure dependent structural, elastic, electronic and optical properties of MF. Non-local correction methods have been employed to capture the weak van der Waals interactions in layered and molecular energetic MF. Among the non-local correction methods tested, optB88-vdW method works well for the investigated compound. The obtained equilibrium bulk modulus reveals that MF is softer than the well known primary explosives Silver Fulminate (SF), silver azide and lead azide. MF exhibits anisotropic compressibility (b > a > c) under pressure, consequently the corresponding elastic moduli decrease in the following order: C22 > C11 > C33. The structural and mechanical properties suggest that MF is more sensitive to detonate along c-axis (similar to RDX) due to high compressibility of Hg⋯O non-bonded interactions along that axis. Electronic structure and optical properties were calculated including spin-orbit (SO) interactions using full potential linearized augmented plane wave method within recently developed Tran-Blaha modified Becke-Johnson (TB-mBJ) potential. The calculated TB-mBJ electronic structures of SF and MF show that these compounds are indirect bandgap insulators. Also, SO coupling is found to be more pronounced for 4d and 5d-states of Ag and Hg atoms of SF and MF, respectively. Partial density of states and electron charge density maps were used to describe the nature of chemical bonding. Ag—C bond is more directional than Hg—C bond which makes SF to be more unstable than MF. The effect of SO coupling on optical properties has also been studied and found to be significant for both (SF and MF) of the compounds.

  19. Reactive Bonding Film for Bonding Carbon Foam Through Metal Extrusion

    CERN Document Server

    Chertok, Maxwell; Irving, Michael; Neher, Christian; Tripathi, Mani; Wang, Ruby; Zheng, Gayle

    2016-01-01

    Future tracking detectors, such as those under development for the High Luminosity LHC, will require mechanical structures employing novel materials to reduce mass while providing excellent strength, thermal conductivity, and radiation tolerance. Adhesion methods for such materials are under study at present. This paper demonstrates the use of reactive bonding film as an adhesion method for bonding carbon foam.

  20. Digital Control of Bonding Force for Gold Wire Bonding Machine

    Directory of Open Access Journals (Sweden)

    Xiaochu Wang

    2013-01-01

    Full Text Available In order to digitally control the bonding force of a wire bonder precisely, this paper uses a DC solenoid as a force source, and by controlling the solenoid’s current, which causes the electromagnetic force, we can control the bonding force that capillary applies. The bonding force control system in this paper is composed of PC (Personal Computer and hypogyny MCU (Micro Controller Unit, which communicate using a RS485 interface. The digital value of a given bonding force is given by the PC to the MCU. By comparing the sampling current of the solenoid, and through PID regulation, D/A converter of the digital potentiometer and the solenoid driver circuit, the half-closed loop control system of bonding force is accomplished. Tuning of the PID parameters is accomplished with fuzzy adaptive control theory and simulated by Matlab simulink. The control system is tested by comparing the desired bonding force and the force actually applied and examming the relationship between bonding quality and bonding force.