Sample records for atmospheric explosions

  1. Explosion characteristics of flammable organic vapors in nitrous oxide atmosphere. (United States)

    Koshiba, Yusuke; Takigawa, Tomihisa; Matsuoka, Yusaku; Ohtani, Hideo


    Despite unexpected explosion accidents caused by nitrous oxide have occurred, few systematic studies have been reported on explosion characteristics of flammable gases in nitrous oxide atmosphere compared to those in air or oxygen. The objective of this paper is to characterize explosion properties of mixtures of n-pentane, diethyl ether, diethylamine, or n-butyraldehyde with nitrous oxide and nitrogen using three parameters: explosion limit, peak explosion pressure, and time to the peak explosion pressure. Then, similar mixtures of n-pentane, diethyl ether, diethylamine, or n-butyraldehyde with oxygen and nitrogen were prepared to compare their explosion characteristics with the mixtures containing nitrous oxide. The explosion experiments were performed in a cylindrical vessel at atmospheric pressure and room temperature. The measurements showed that explosion ranges of the mixtures containing nitrous oxide were narrow compared to those of the mixtures containing oxygen. On the other hand, the maximum explosion pressures of the mixtures containing nitrous oxide were higher than those of the mixtures containing oxygen. Moreover, our experiments revealed that these mixtures differed in equivalence ratios at which the maximum explosion pressures were observed: the pressures of the mixtures containing nitrous oxide were observed at stoichiometry; in contrast, those of the mixtures containing oxygen were found at fuel-rich area. Chemical equilibrium calculations confirmed these behaviors. Copyright © 2010 Elsevier B.V. All rights reserved.

  2. Atmospheric emission of NOx from mining explosives: A critical review (United States)

    Oluwoye, Ibukun; Dlugogorski, Bogdan Z.; Gore, Jeff; Oskierski, Hans C.; Altarawneh, Mohammednoor


    High-energy materials such as emulsions, slurries and ammonium-nitrate fuel-oil (ANFO) explosives play crucial roles in mining, quarrying, tunnelling and many other infrastructure activities, because of their excellent transport and blasting properties. These explosives engender environmental concerns, due to atmospheric pollution caused by emission of dust and nitrogen oxides (NOx) from blasts, the latter characterised by the average emission factor of 5 kg (t AN explosive)-1. This first-of-its-kind review provides a concise literature account of the formation of NOx during blasting of AN-based explosives, employed in surface operations. We estimate the total NOx emission rate from AN-based explosives as 0.05 Tg (i.e., 5 × 104 t) N per annum, compared to the total global annual anthropogenic NOx emissions of 41.3 × 106 t N y-1. Although minor in the global sense, the large localised plumes from blasting exhibit high NOx concentration (500 ppm) exceeding up to 3000 times the international standards. This emission has profound consequences at mining sites and for adjacent atmospheric environment, necessitating expensive management of exclusion zones. The review describes different types of AN energetic materials for civilian applications, and summarises the essential properties and terminologies pertaining to their use. Furthermore, we recapitulate the mechanisms that lead to the formation of the reactive nitrogen species in blasting of AN-based explosives, review their implications to atmospheric air pollution, and compare the mechanisms with those experienced in other thermal and combustion operations. We also examine the mitigation approaches, including guidelines and operational-control measures. The review discusses the abatement technologies such as the formulation of new explosive mixtures, comprising secondary fuels, spin traps and other additives, in light of their effectiveness and efficiency. We conclude the review with a summary of unresolved problems

  3. ATEX explosive atmospheres : risk assessment, control and compliance

    CERN Document Server

    Jespen, Torben


    This book details how safety (i.e. the absence of unacceptable risks) is ensured in areas where potentially explosive atmospheres (ATEX) can arise. The book also offers readers essential information on how to comply with the newest (April 2016) EU legislation when the presence of ATEX cannot be avoided. By presenting general guidance on issues arising out of the EU ATEX legislation – especially on zone classification, explosion risk assessment, equipment categorization, Ex-marking and related technical/chemical aspects – the book provides equipment manufacturers, responsible employers, and others with the essential knowledge they need to be able to understand the different – and often complicated – aspects of ATEX and to implement the necessary safety precautions. As such, it represents a valuable resource for all those concerned with maintaining high levels of safety in ATEX environments.

  4. North Atlantic explosive cyclones and large scale atmospheric variability modes (United States)

    Liberato, Margarida L. R.


    Extreme windstorms are one of the major natural catastrophes in the extratropics, one of the most costly natural hazards in Europe and are responsible for substantial economic damages and even fatalities. During the last decades Europe witnessed major damage from winter storms such as Lothar (December 1999), Kyrill (January 2007), Klaus (January 2009), Xynthia (February 2010), Gong (January 2013) and Stephanie (February 2014) which exhibited uncommon characteristics. In fact, most of these storms crossed the Atlantic in direction of Europe experiencing an explosive development at unusual lower latitudes along the edge of the dominant North Atlantic storm track and reaching Iberia with an uncommon intensity (Liberato et al., 2011; 2013; Liberato 2014). Results show that the explosive cyclogenesis process of most of these storms at such low latitudes is driven by: (i) the southerly displacement of a very strong polar jet stream; and (ii) the presence of an atmospheric river (AR), that is, by a (sub)tropical moisture export over the western and central (sub)tropical Atlantic which converges into the cyclogenesis region and then moves along with the storm towards Iberia. Previous studies have pointed to a link between the North Atlantic Oscillation (NAO) and intense European windstorms. On the other hand, the NAO exerts a decisive control on the average latitudinal location of the jet stream over the North Atlantic basin (Woollings et al. 2010). In this work the link between North Atlantic explosive cyclogenesis, atmospheric rivers and large scale atmospheric variability modes is reviewed and discussed. Liberato MLR (2014) The 19 January 2013 windstorm over the north Atlantic: Large-scale dynamics and impacts on Iberia. Weather and Climate Extremes, 5-6, 16-28. doi: 10.1016/j.wace.2014.06.002 Liberato MRL, Pinto JG, Trigo IF, Trigo RM. (2011) Klaus - an exceptional winter storm over Northern Iberia and Southern France. Weather 66:330-334. doi:10.1002/wea.755 Liberato

  5. The concurrence of atmospheric rivers and explosive cyclogenesis in the North Atlantic and North Pacific basins

    Directory of Open Access Journals (Sweden)

    J. Eiras-Barca


    Full Text Available The explosive cyclogenesis of extratropical cyclones and the occurrence of atmospheric rivers are characteristic features of a baroclinic atmosphere, and are both closely related to extreme hydrometeorological events in the mid-latitudes, particularly on coastal areas on the western side of the continents. The potential role of atmospheric rivers in the explosive cyclone deepening has been previously analysed for selected case studies, but a general assessment from the climatological perspective is still missing. Using ERA-Interim reanalysis data for 1979–2011, we analyse the concurrence of atmospheric rivers and explosive cyclogenesis over the North Atlantic and North Pacific basins for the extended winter months (ONDJFM. Atmospheric rivers are identified for almost 80 % of explosive deepening cyclones. For non-explosive cyclones, atmospheric rivers are found only in roughly 40 % of the cases. The analysis of the time evolution of the high values of water vapour flux associated with the atmospheric river during the cyclone development phase leads us to hypothesize that the identified relationship is the fingerprint of a mechanism that raises the odds of an explosive cyclogenesis occurrence and not merely a statistical relationship. These new insights on the relationship between explosive cyclones and atmospheric rivers may be helpful to a better understanding of the associated high-impact weather events.

  6. Detection of Atmospheric Explosions at IMS Monitoring Stations using Infrasound Techniques

    National Research Council Canada - National Science Library

    Christie, Douglas R; Kennett, Brian L; Tarlowski, Chris


    Work is continuing on the development of infrasound techniques that can be used to improve detection, location and discrimination capability for atmospheric nuclear explosions at International Monitoring System (IMS...

  7. Numerical simulation of detonation of an explosive atmosphere of liquefied petroleum gas in a confined space

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    Niculae Serban Costin


    Full Text Available The detonation of an explosive atmosphere from liquefied petroleum gas disseminated in air in a confined space is studied using numerical modeling with software product ANSYS AUTODYN.

  8. Characteristics of acoustic wave from atmospheric nuclear explosions conducted at the USSR Test Sites (United States)

    Sokolova, Inna


    Availability of the acoustic wave on the record of microbarograph is one of discriminate signs of atmospheric (surface layer of atmosphere) and contact explosions. Nowadays there is large number of air wave records from chemical explosions recorded by the IMS infrasound stations installed during recent decade. But there is small number of air wave records from nuclear explosions as air and contact nuclear explosions had been conducted since 1945 to 1962, before the Limited Test Ban Treaty was signed in 1963 (the treaty banning nuclear weapon tests in the atmosphere, in outer space and under water) by the Great Britain, USSR and USA. That time there was small number of installed microbarographs. First infrasound stations in the USSR appeared in 1954, and by the moment of the USSR collapse the network consisted of 25 infrasound stations, 3 of which were located on Kazakhstan territory - in Kurchatov (East Kazakhstan), in Borovoye Observatory (North Kazakhstan) and Talgar Observatory (Northern Tien Shan). The microbarograph of Talgar Observatory was installed in 1962 and recorded large number of air nuclear explosions conducted at Semipalatinsk Test Site and Novaya Zemlya Test Site. The epicentral distance to the STS was ~700 km, and to Novaya Zemlya Test Site ~3500 km. The historical analog records of the microbarograph were analyzed on the availability of the acoustic wave. The selected records were digitized, the database of acoustic signals from nuclear explosions was created. In addition, acoustic signals from atmospheric nuclear explosions conducted at the USSR Test Sites were recorded by analogue broadband seismic stations at wide range of epicentral distances, 300-3600 km. These signals coincide well by its form and spectral content with records of microbarographs and can be used for monitoring tasks and discrimination in places where infrasound observations are absent. Nuclear explosions which records contained acoustic wave were from 0.03 to 30 kt yield for

  9. Description and validation of ERAD: An atmospheric dispersion model for high explosive detonations

    Energy Technology Data Exchange (ETDEWEB)

    Boughton, B.A.; DeLaurentis, J.M.


    The Explosive Release Atmospheric Dispersion (ERAD) model is a three-dimensional numerical simulation of turbulent atmospheric transport and diffusion. An integral plume rise technique is used to provide a description of the physical and thermodynamic properties of the cloud of warm gases formed when the explosive detonates. Particle dispersion is treated as a stochastic process which is simulated using a discrete time Lagrangian Monte Carlo method. The stochastic process approach permits a more fundamental treatment of buoyancy effects, calm winds and spatial variations in meteorological conditions. Computational requirements of the three-dimensional simulation are substantially reduced by using a conceptualization in which each Monte Carlo particle represents a small puff that spreads according to a Gaussian law in the horizontal directions. ERAD was evaluated against dosage and deposition measurements obtained during Operation Roller Coaster. The predicted contour areas average within about 50% of the observations. The validation results confirm the model`s representation of the physical processes.

  10. Evaluation of a sheathed permissible explosive charge for open shooting in flammable atmospheres: Adobe charge program (United States)

    Mainiero, R. J.; Hay, J. E.


    A prototype nonincendive explosive rock-breaker charge that can be fired unconfined in underground bituminous coal mines without the danger of igniting a flammable atmosphere that might be present is described. At present, unconfined shooting in underground coal mines is prohibited, but there are situations where the use of such shots would yield an overall improvement in safety. The charge consists of 1-1/2 lb of permissible water gel explosive in the form of a short cylinder 7 inches in diameter and 7/8 inches high, surrounded by a 1/2-inch-thick layer of damp salt, and encased in latex rubber reinforced with cheese cloth. The latex rubber housing provides a charge package that is strong enough to resist rough handling yet is pliable enough to conform to an irregular stone surface. A charge of this shape was found to be more effective at breaking rock than charges with lined or unlined cavities.

  11. High explosives vapor detection by atmospheric sampling glow discharge ionization/tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    McLuckey, S.A.; Goeringer, D.E.; Asano, K.G. [Oak Ridge National Lab., TN (United States). Chemical and Analytical Sciences Div.


    The combination of atmospheric sampling glow discharge ionization with tandem mass spectrometry for the detection of traces of high explosives is described. Particular emphasis is placed on use of the quadrupole ion trap as the type of tandem mass spectrometer. Atmospheric sampling glow discharge provides a simple, rugged, and efficient means for anion formation while the quadrupole ion trap provides for efficient tandem mass spectrometry. Mass selective ion accumulation and non-specific ion activation methods can be used to overcome deleterious effects arising from ion/ion interactions. Such interactions constitute the major potential technical barrier to the use of the ion trap for real-time monitoring of targeted compounds in uncontrolled and highly variable matrices. Tailored waveforms can be used to effect both mass selective ion accumulation and ion activation. Concatenated tailored waveforms allow for both functions in a single experiment thereby providing the capability for monitoring several targeted species simultaneously. The combination of atmospheric sampling glow discharge ionization with a state-of-the-art analytical quadrupole ion trap is a highly sensitive and specific detector for traces of high explosives. The combination is also small and inexpensive relative to virtually any other form of tandem mass spectrometry. The science and technology underlying the glow discharge/ion trap combination is sufficiently mature to form the basis for an engineering effort to make the detector portable. 85 refs.

  12. Models for close-in atmospheric dispersion, explosive releases, and particle deposition

    Energy Technology Data Exchange (ETDEWEB)

    Bloom, S.G.


    Relatively simple models are presented to simulate close-in atmospheric dispersion, explosive releases, and particle deposition. Close-in generally refers to distances less than 50 m downwind from the source. These models assume simple gas dispersion (no chemical reactions, neutral buoyancy) and that particles behave as a gas expect they can be removed from the plume by a simple, deposition-velocity mechanism. These models have been combined into a QuickBASIC program (INEXPLC.BAS) and its PC executable form (INEXPLC.EXE). These programs, along with sample input and output files, are available from the author.

  13. Analysis of nitrogen-based explosives with desorption atmospheric pressure photoionization mass spectrometry. (United States)

    Kauppila, T J; Flink, A; Pukkila, J; Ketola, R A


    Fast methods that allow the in situ analysis of explosives from a variety of surfaces are needed in crime scene investigations and home-land security. Here, the feasibility of the ambient mass spectrometry technique desorption atmospheric pressure photoionization (DAPPI) in the analysis of the most common nitrogen-based explosives is studied. DAPPI and desorption electrospray ionization (DESI) were compared in the direct analysis of trinitrotoluene (TNT), trinitrophenol (picric acid), octogen (HMX), cyclonite (RDX), pentaerythritol tetranitrate (PETN), and nitroglycerin (NG). The effect of different additives in DAPPI dopant and in DESI spray solvent on the ionization efficiency was tested, as well as the suitability of DAPPI to detect explosives from a variety of surfaces. The analytes showed ions only in negative ion mode. With negative DAPPI, TNT and picric acid formed deprotonated molecules with all dopant systems, while RDX, HMX, PETN and NG were ionized by adduct formation. The formation of adducts was enhanced by addition of chloroform, formic acid, acetic acid or nitric acid to the DAPPI dopant. DAPPI was more sensitive than DESI for TNT, while DESI was more sensitive for HMX and picric acid. DAPPI could become an important method for the direct analysis of nitroaromatics from a variety of surfaces. For compounds that are thermally labile, or that have very low vapor pressure, however, DESI is better suited. Copyright © 2016 John Wiley & Sons, Ltd.

  14. Multiparametric Study of Wind and Atmosphere Effect on Explosive Eruptive Style (United States)

    Engwell, S. L.; Barsotti, S.; De'Michieli Vitturi, M.; Neri, A.


    The atmospheric environment interacts with volcanic plumes produced by explosive eruptions in a number of ways. The wind field can affect atmospheric air entrainment into the column favouring its buoyancy. Similarly, the structure of the atmosphere and its properties can significantly influence the dynamics of volcanic plumes. In recent years, several numerical simulation tools and observation systems have investigated the action of wind field and atmospheric properties on volcanic column height and bending, revealing an important influence of these variables on plume behavior. A less explored issue is the action of wind and atmospheric properties on the eruptive style, i.e. on the buoyant or collapsing regimes shown by the plume, and the factors controlling the shift from one regime to the other. In this study, we address these issues using a new numerical simulation tool for solving the plume theory equations. This tool, named PlumeMoM (de'Michieli Vitturi et al., in preparation), allows the continuous polydispersity of pyroclastic particles to be described using a quadrature-based moment method, an innovative approach in volcanology well-suited for the description of the multiphase nature of magmatic mixture. Several physical processes and real conditions were considered: loss of mass along the column, entrainment of atmospheric air, vertical profiles of atmospheric temperature and density, and atmospheric stability A global sensitivity analysis of the effects of these parameters on plume dynamics and stability was also performed by coupling the plume model with the DAKOTA statistics toolkit. Results provide a better understanding of the key processes affecting plume regime and identification of the main parameters controlling column behaviour.

  15. Numerical simulation of explosive volcanic eruptions from the conduit flow to global atmospheric scales

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    G. G. J. Ernst


    Full Text Available Volcanic eruptions are unsteady multiphase phenomena, which encompass many inter-related processes across the whole range of scales from molecular and microscopic to macroscopic, synoptic and global. We provide an overview of recent advances in numerical modelling of volcanic effects, from conduit and eruption column processes to those on the Earth s climate. Conduit flow models examine ascent dynamics and multiphase processes like fragmentation, chemical reactions and mass transfer below the Earth surface. Other models simulate atmospheric dispersal of the erupted gas-particle mixture, focusing on rapid processes occurring in the jet, the lower convective regions, and pyroclastic density currents. The ascending eruption column and intrusive gravity current generated by it, as well as sedimentation and ash dispersal from those flows in the immediate environment of the volcano are examined with modular and generic models. These apply simplifications to the equations describing the system depending on the specific focus of scrutiny. The atmospheric dispersion of volcanic clouds is simulated by ash tracking models. These are inadequate for the first hours of spreading in many cases but focus on long-range prediction of ash location to prevent hazardous aircraft - ash encounters. The climate impact is investigated with global models. All processes and effects of explosive eruptions cannot be simulated by a single model, due to the complexity and hugely contrasting spatial and temporal scales involved. There is now the opportunity to establish a closer integration between different models and to develop the first comprehensive description of explosive eruptions and of their effects on the ground, in the atmosphere, and on the global climate.

  16. Categorisation of nuclear explosions from legitimate radioxenon sources with atmospheric transport modelling (United States)

    Schoeppner, M.; Postelt, F.; Kalinowski, M.; Plastino, W.


    Radioxenon is produced during nuclear explosions and due to its high fission ratio during the reaction and its noble gas character the isotopes can be detected remote from the location of the explosion. Therefore it is used by the Comprehensive Nuclear-Test-Ban Organization (CTBTO) as an indicator for the nuclear character of an explosion and is monitored with the International Monitoring System (IMS). The concentration of radioxenon in the air is continuously measured by multiple stations worldwide and is in need of an automatic categorization scheme in order to highlight signals of interest and to sort out signals that can be explained by legitimate sources. The dispersion and transport of radioxenon emissions through the atmosphere can be simulated with atmospheric transport modelling. Many legitimate sources of radioxenon exist: Nuclear power plants and isotope production facilities are mainly responsible for the worldwide background. The characterisation of this background is an important prerequisite to discriminate nuclear explosion signals against the background. It has been discovered that the few existing isotope production facilities are the major contributors to the background, each with emission strengths in the order of magnitude or more than all nuclear power plants together. Therefore, especially the characterization of these few, but strong, emitters can improve the quality of the signal prediction. Since the location of such an emitter is usually known the source-receptor sensitivity matrices can be utilized together with measured radioxenon concentrations from IMS stations in order to deduct information about the time dependent emissions from the strong emitter. An automatic method to determine an approximated, time dependent source term of an emitter with known location has been developed and is presented. This is a potentially valid tool for the categorization of radioxenon samples, because it can be used to assess whether the measured

  17. Sensitivity of atmospheric CO2 and climate to explosive volcanic eruptions

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    C. C. Raible


    Full Text Available Impacts of low-latitude, explosive volcanic eruptions on climate and the carbon cycle are quantified by forcing a comprehensive, fully coupled carbon cycle-climate model with pulse-like stratospheric aerosol optical depth changes. The model represents the radiative and dynamical response of the climate system to volcanic eruptions and simulates a decrease of global and regional atmospheric surface temperature, regionally distinct changes in precipitation, a positive phase of the North Atlantic Oscillation, and a decrease in atmospheric CO2 after volcanic eruptions. The volcanic-induced cooling reduces overturning rates in tropical soils, which dominates over reduced litter input due to soil moisture decrease, resulting in higher land carbon inventories for several decades. The perturbation in the ocean carbon inventory changes sign from an initial weak carbon sink to a carbon source. Positive carbon and negative temperature anomalies in subsurface waters last up to several decades. The multi-decadal decrease in atmospheric CO2 yields a small additional radiative forcing that amplifies the cooling and perturbs the Earth System on longer time scales than the atmospheric residence time of volcanic aerosols. In addition, century-scale global warming simulations with and without volcanic eruptions over the historical period show that the ocean integrates volcanic radiative cooling and responds for different physical and biogeochemical parameters such as steric sea level or dissolved oxygen. Results from a suite of sensitivity simulations with different magnitudes of stratospheric aerosol optical depth changes and from global warming simulations show that the carbon cycle-climate sensitivity γ, expressed as change in atmospheric CO2 per unit change in global mean surface temperature, depends on the magnitude and temporal evolution of the perturbation, and time scale of interest. On decadal time scales, modeled γ is several times larger for a

  18. Innovative concept for a major breakthrough in atmospheric radioactive xenon detection for nuclear explosion monitoring. (United States)

    Le Petit, G; Cagniant, A; Morelle, M; Gross, P; Achim, P; Douysset, G; Taffary, T; Moulin, C

    The verification regime of the comprehensive test ban treaty (CTBT) is based on a network of three different waveform technologies together with global monitoring of aerosols and noble gas in order to detect, locate and identify a nuclear weapon explosion down to 1 kt TNT equivalent. In case of a low intensity underground or underwater nuclear explosion, it appears that only radioactive gases, especially the noble gas which are difficult to contain, will allow identification of weak yield nuclear tests. Four radioactive xenon isotopes, 131mXe, 133mXe, 133Xe and 135Xe, are sufficiently produced in fission reactions and exhibit suitable half-lives and radiation emissions to be detected in atmosphere at low level far away from the release site. Four different monitoring CTBT systems, ARIX, ARSA, SAUNA, and SPALAX™ have been developed in order to sample and to measure them with high sensitivity. The latest developed by the French Atomic Energy Commission (CEA) is likely to be drastically improved in detection sensitivity (especially for the metastable isotopes) through a higher sampling rate, when equipped with a new conversion electron (CE)/X-ray coincidence spectrometer. This new spectrometer is based on two combined detectors, both exhibiting very low radioactive background: a well-type NaI(Tl) detector for photon detection surrounding a gas cell equipped with two large passivated implanted planar silicon chips for electron detection. It is characterized by a low electron energy threshold and a much better energy resolution for the CE than those usually measured with the existing CTBT equipments. Furthermore, the compact geometry of the spectrometer provides high efficiency for X-ray and for CE associated to the decay modes of the four relevant radioxenons. The paper focus on the design of this new spectrometer and presents spectroscopic performances of a prototype based on recent results achieved from both radioactive xenon standards and air sample measurements

  19. An assessment on the PTS global radionuclide monitoring capabilities to detect the atmospheric traces of nuclear explosions (United States)

    Becker, Andreas; Wotawa, Gerhard; Auer, Matthias; Krysta, Monika


    In order to detect any kind of nuclear explosion world-wide the Provisional Technical Secretariat to the Comprehensive Nuclear-Test-Ban Treaty (CTBT) is building up a verification regime that performs global monitoring for typical signals expected from such an event. Backbone of this regime is the 321 facilities International Monitoring System (IMS) comprising 80 stations to monitor for particulate radionuclides known to be fission or activation products of a nuclear explosion. Every second station is also equipped with a system capable to monitor for the occurrence of the CTBT relevant isotopes Xe-131m, Xe-133, Xe-133m, and Xe-135, which have the highest post-explosion fission yields among the noble gases, and are also not subject to wet deposition in the atmosphere. Moreover, they have a good chance to escape from the cavity of an underground nuclear explosion in contrast to the particulates. Effective radionuclide monitoring requires an optimum overall probability of a one-station detection of an atmospheric or underground nuclear explosion within 14 days. Consequently, the distribution of this detection probability is crucial for assessing the capacity of the radionuclide IMS to meet this requirement. The CTBT monitoring capabilities of the RN IMS are quite different in dependence on the environment in which the nuclear test is conducted (underground, underwater or atmospheric) as this determines the first crucial factor for the overall detection probability, the degree of containment. Secondly, the detection probability is subject to the nuclide specific decay and the dilution of any release (containment failure) during its atmospheric dispersion from the release location to one of the IMS stations. Thirdly, the detection limits of the measurement systems in use factor in. In the study presented here the radionuclide monitoring capabilities for detecting atmospheric and underground explosions, the latter mimicked by a 90% contained atmospheric release (first

  20. Atmospheric Pressure Chemical Ionization Sources Used in The Detection of Explosives by Ion Mobility Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Waltman, Melanie J. [New Mexico Inst. of Mining and Technology, Socorro, NM (United States)


    Explosives detection is a necessary and wide spread field of research. From large shipping containers to airline luggage, numerous items are tested for explosives every day. In the area of trace explosives detection, ion mobility spectrometry (IMS) is the technique employed most often because it is a quick, simple, and accurate way to test many items in a short amount of time. Detection by IMS is based on the difference in drift times of product ions through the drift region of an IMS instrument. The product ions are created when the explosive compounds, introduced to the instrument, are chemically ionized through interactions with the reactant ions. The identity of the reactant ions determines the outcomes of the ionization process. This research investigated the reactant ions created by various ionization sources and looked into ways to manipulate the chemistry occurring in the sources.


    Directory of Open Access Journals (Sweden)

    Mihai MAGYARI


    Full Text Available The electric power drive systems consisting of three phase induction motor and static frequency converter are designed to enhance the performance on site, by diminishing the energy consumption, optimization of the technological processes and the reduction of costs for the maintenance and repairs of the equipment. The paper presents some important issues concerning the selection of inverter fed flameproof electric drives in the field of potentially explosive atmospheres of gases and vapors by ensuring a correct risk management against the hazard of electric sparks as well as excessive temperatures.

  2. Explosion of red-supergiant stars: Influence of the atmospheric structure on shock breakout and early-time supernova radiation (United States)

    Dessart, Luc; John Hillier, D.; Audit, Edouard


    Early-time observations of Type II supernovae (SNe) 2013cu and 2013fs have revealed an interaction of ejecta with material near the star surface. Unlike Type IIn SN 2010jl, which interacts with a dense wind for 1 yr, the interaction ebbs after 2-3 d, suggesting a dense and compact circumstellar envelope. Here, we use multi-group radiation hydrodynamics and non-local-thermodynamic-equilibrium radiative transfer to explore the properties of red-supergiant (RSG) star explosions embedded in a variety of dense envelopes. We consider the cases of an extended static atmosphere or a steady-state wind, adopting a range of mass loss rates. The shock breakout signal, luminosity and color evolution up to 10 d, and ejecta dynamics are strongly influenced by the properties of this nearby environment. This compromises the use of early-time observations to constrain R⋆. For dense circumstellar envelopes, the time-integrated luminosity over the first 10-15 d can be boosted by a factor of a few. The presence of narrow lines for 2-3 d in 2013fs and 2013cu require a cocoon of material of 0.01 M⊙ out to 5-10 R⋆. Spectral lines evolve from electron scattering to Doppler broadened with a growing blueshift of their emission peaks. Recent studies propose a super-wind phase with a mass loss rate from 0.001 up to 1 M⊙ yr-1 in the last months or years of the life of a RSG, although there is no observational constraint that this external material is a steady-state outflow. Alternatively, observations may be explained by the explosion of a RSG star inside its complex atmosphere. Indeed, spatially resolved observations reveal that RSG stars have extended atmospheres, with the presence of downflows and upflows out to several R⋆, even in a standard RSG such as Betelgeuse. Mass loading in the region intermediate between star and wind can accommodate the 0.01 M⊙ needed to explain the observations of 2013fs. Signatures of interaction in early-time spectra of RSG star explosions may

  3. Characterization of the improvised explosive urea nitrate using electrospray ionization and atmospheric pressure chemical ionization. (United States)

    Tamiri, Tsippy


    Mass spectra of urea nitrate were measured in electrospray ionization and in atmospheric pressure chemical ionization in the negative mode. In both ionization methods two characteristic adduct ions containing the intact molecule [urea nitrate+NO3]- and [urea nitrate+HNO3+NO3]- are shown. The structure of the two adduct ions was deduced using measurements of isotopically labeled urea nitrate. Collision-induced dissociation measurements of the adduct ions show typical losses enabling the identification of urea nitrate in trace amounts. Using these methods urea nitrate was identified in real cases. Copyright (c) 2005 John Wiley & Sons, Ltd.

  4. In situ trace detection of peroxide explosives by desorption electrospray ionization and desorption atmospheric pressure chemical ionization. (United States)

    Cotte-Rodríguez, Ismael; Hernandez-Soto, Heriberto; Chen, Hao; Cooks, R Graham


    Desorption electrospray ionization (DESI) mass spectrometry is used for the rapid (process triggered by an unusual homolytic cleavage of the peroxide bond, forming a distonic ion. This is followed by elimination of a fragment of 30 mass units, shown to be the expected neutral molecule, formaldehyde, in the case of HMTD, but shown by isotopic labeling experiments to be ethane in the cases of TATP and TrATrP. Density functional theory (DFT) calculations support the suggested fragmentation mechanisms for the complexes. Binding energies of Na+ of 40.2 and 33.1 kcal/mol were calculated for TATP-Na(+) and HMTD-Na(+) complexes, suggesting a strong interaction between the peroxide groups and the sodium ion. Increased selectivity is obtained either by MS/MS or by doping the spray solvent with additives that produce the lithium and potassium complexes of TATP, HMTD, and TrATrP. Addition of dopants into the solvent spray increased the signal intensity by an order of magnitude. When pure alcohol or aqueous hydrogen peroxide was used as the spray solvent, the (HMTD + Na)+ complex was able to bind a molecule of alcohol (methanol or ethanol) or hydrogen peroxide, providing additional characteristic ions to increase the selectivity of analysis. DESI also allowed the rapid detection of peroxide explosives in complex matrixes such as diesel fuel and lubricants using single or multiple cation additives (Na(+), K(+), and Li(+), and NH4(+)) in the spray solvent. Low-nanogram detection limits were achieved for HMTD, TrATrP, and TATP in these complex matrixes. The DESI response was linear over 3 orders of magnitude for HMTD and TATP on paper surfaces (1-5000 ng), and quantification of both peroxide explosives from paper gave precisions (RSD) of less than 3%. The use of pure water and compressed air as the DESI spray solution and nebulizing gas, respectively, showed similar ionization efficiencies to those obtained using methanol/water mixtures and nitrogen gas (the typical choices). An

  5. Multi-wavelength Observations of Two Explosive Events and Their Effects on the Solar Atmosphere

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    Agustinus G. Admiranto


    Full Text Available We investigated two flares in the solar atmosphere that occurred on June 3, 2012 and July 6, 2012 and caused propagation of Moreton and EIT waves. In the June 3 event, we noticed a filament winking which presumably was caused by the wave propagation from the flare. An interesting feature of this event is that there was a reflection of this wave by a coronal hole located alongside the wave propagation, but not all of this wave was transmitted by the coronal hole. Using the running difference method, we calculated the speed of Moreton and EIT waves and we found values of 926 km/s before the reflection and 276 km/s after the reflection (Moreton wave and 1,127 km/s before the reflection and 46 km/s after the reflection (EIT wave. In the July 6 event, this phenomenon was accompanied by type II and type III solar radio bursts, and we also performed a running difference analysis to find the speed of the Moreton wave, obtaining a value of 988 km/s. The speed derived from the analysis of the solar radio burst was 1,200 km/s, and we assume that this difference was caused by the different nature of the motions in these phenomena, where the solar radio burst was caused by the propagating particles, not waves.

  6. exLOPA for explosion risks assessment. (United States)

    Markowski, Adam S


    The European Union regulations require safety and health protection of workers who are potentially at risk from explosive atmosphere areas. According to the requirements, the operators of installations where potentially explosive atmosphere can occur are obliged to produce an explosion protection document. The key objective of this document is the assessment of explosion risks. This paper is concerned with the so-called explosion layer of protection analysis (exLOPA), which allows for semi-quantitative explosion risk assessment for process plants where explosive atmospheres occur. The exLOPA is based on the original work of CCPS for LOPA but takes into account some typical factors appropriate for explosion, like the probability that an explosive atmosphere will occur, probability that sources of ignition will be present and become effective as well as the probability of failure on demand for appropriate explosion prevention and mitigation means.

  7. Explosives tester (United States)

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


    An explosives tester that can be used anywhere as a screening tool by non-technical personnel to determine whether a surface contains explosives. First and second explosives detecting reagent holders and dispensers are provided. A heater is provided for receiving the first and second explosives detecting reagent holders and dispensers.

  8. Primary explosives

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  9. Liquid explosives

    CERN Document Server

    Liu, Jiping


    The book drawing on the author's nearly half a century of energetic materials research experience intends to systematically review the global researches on liquid explosives. The book focuses on the study of the conception, explosion mechanism, properties and preparation of liquid explosives. It provides a combination of theoretical knowledge and practical examples in a reader-friendly style. The book is likely to be interest of university researchers and graduate students in the fields of energetic materials, blasting engineering and mining.

  10. Explosive compositions

    Energy Technology Data Exchange (ETDEWEB)

    Craig, J.F.M.; Falconer, E.L.


    A thickening agent for an aqueous slurry explosive composition consists of the combination of a cross-linked galactomannan with psyllium flour in specific proportions. This thickener provides good fluidity and reduced tackiness. (7 claims)

  11. Explosive detection technology (United States)

    Doremus, Steven; Crownover, Robin


    The continuing proliferation of improvised explosive devices is an omnipresent threat to civilians and members of military and law enforcement around the world. The ability to accurately and quickly detect explosive materials from a distance would be an extremely valuable tool for mitigating the risk posed by these devices. A variety of techniques exist that are capable of accurately identifying explosive compounds, but an effective standoff technique is still yet to be realized. Most of the methods being investigated to fill this gap in capabilities are laser based. Raman spectroscopy is one such technique that has been demonstrated to be effective at a distance. Spatially Offset Raman Spectroscopy (SORS) is a technique capable of identifying chemical compounds inside of containers, which could be used to detect hidden explosive devices. Coherent Anti-Stokes Raman Spectroscopy (CARS) utilized a coherent pair of lasers to excite a sample, greatly increasing the response of sample while decreasing the strength of the lasers being used, which significantly improves the eye safety issue that typically hinders laser-based detection methods. Time-gating techniques are also being developed to improve the data collection from Raman techniques, which are often hindered fluorescence of the test sample in addition to atmospheric, substrate, and contaminant responses. Ultraviolet based techniques have also shown significant promise by greatly improved signal strength from excitation of resonance in many explosive compounds. Raman spectroscopy, which identifies compounds based on their molecular response, can be coupled with Laser Induced Breakdown Spectroscopy (LIBS) capable of characterizing the sample's atomic composition using a single laser.

  12. 30 CFR 77.304 - Explosion release vents. (United States)


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Explosion release vents. 77.304 Section 77.304... Dryers § 77.304 Explosion release vents. Drying chambers, dry-dust collectors, ductwork connecting dryers... explosion release vents which open directly to the outside atmosphere, and all such vents shall be: (a...

  13. Explosive Pleuritis

    Directory of Open Access Journals (Sweden)

    Jasdeep K Sharma


    Full Text Available The objective of the present paper is to describe the clinical and computed tomography features of 'explosive pleuritis', an entity first named by Braman and Donat in 1986, and to propose a case definition. A case report of a previously healthy, 45-year-old man admitted to hospital with acute onset pleuritic chest pain is presented. The patient arrived at the emergency room at 15:00 in mild respiratory distress; the initial chest x-ray revealed a small right lower lobe effusion. The subsequent clinical course in hospital was dramatic. Within 18 h of admission, he developed severe respiratory distress with oxygen desaturation to 83% on room air and dullness of the right lung field. A repeat chest x-ray, taken the morning after admission, revealed complete opacification of the right hemithorax. A computed tomography scan of the thorax demonstrated a massive pleural effusion with compression of pulmonary tissue and mediastinal shift. Pleural fluid biochemical analysis revealed the following concentrations: glucose 3.5 mmol/L, lactate dehydrogenase 1550 U/L, protein 56.98 g/L, amylase 68 U/L and white blood cell count 600 cells/mL. The pleural fluid cultures demonstrated light growth of coagulase-negative staphylococcus and viridans streptococcus, and very light growth of Candida albicans. Cytology was negative for malignant cells. Thoracotomy was performed, which demonstrated a loculated parapneumonic effusion that required decortication. The patient responded favourably to the empirical administration of intravenous levofloxacin and ceftriaxone, and conservative surgical methods in the management of the empyema. This report also discusses the patient's rapidly progressing pleural effusion and offers a potential case definition for explosive pleuritis. Explosive pleuritis is a medical emergency defined by the rapid development of a pleural effusion involving more than 90% of the hemithorax over 24 h, which causes compression of pulmonary tissue and

  14. Intravesical explosion during transurethral electrosurgery. (United States)

    Georgios, Kallinikas; Evangelos, Boulinakis; Helai, Habib; Ioannis, Gerzelis


    Intravesical explosion is a very rare complication of transurethral resection of prostate and transurethral resection of bladder tumour operations. In vitro studies have shown that the gases produced during the procedure could result in a blast once they are mixed with air from the atmosphere. A 79-year-old male experienced an explosion in his bladder while undergoing a transurethral resection of bladder tumour. The case is presented as well as the way that it was treated as an emergency. Precautions of such events are finally suggested. © The Author(s) 2015 Reprints and permissions:

  15. Explosive Formulation Pilot Plant (United States)

    Federal Laboratory Consortium — The Pilot Plant for Explosive Formulation supports the development of new explosives that are comprised of several components. This system is particularly beneficial...

  16. Underground Explosions (United States)


    is viewed as a result of the propulsion of broken rock mass by explosion gas by-products. The physical model used to recreate the second and the third...period seismographs. Seismologists of the                                                              5  Edinaya  Sistema   Seismicheskih  Nablyudenii...d’explosifs chiniques dans le sable: Programme Dynasol, Centre d’etudes Nucl. De Grenoble Lab. D’applications Speciales de la Physique, Grenoble. 9

  17. Detection of Nuclear Explosions Using Infrasound Techniques (United States)


    state-of-the- art wind-noise reduction systems, turbulent wind noise will prevent the detection of infrasonic signals from atmospheric explosions over...D.R., J.A. Vivas Veloso, P. Campus, M. Bell, T. Hoffmann, A. Langlois, P. Martysevich, E. Demirovic and J. Carvalho (2001). Detection of atmospheric

  18. Chemical profiling of explosives

    NARCIS (Netherlands)

    Brust, G.M.H.


    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

  19. Supernova explosions

    CERN Document Server

    Branch, David


    Targeting advanced students of astronomy and physics, as well as astronomers and physicists contemplating research on supernovae or related fields, David Branch and J. Craig Wheeler offer a modern account of the nature, causes and consequences of supernovae, as well as of issues that remain to be resolved. Owing especially to (1) the appearance of supernova 1987A in the nearby Large Magellanic Cloud, (2) the spectacularly successful use of supernovae as distance indicators for cosmology, (3) the association of some supernovae with the enigmatic cosmic gamma-ray bursts, and (4) the discovery of a class of superluminous supernovae, the pace of supernova research has been increasing sharply. This monograph serves as a broad survey of modern supernova research and a guide to the current literature. The book’s emphasis is on the explosive phases of supernovae. Part 1 is devoted to a survey of the kinds of observations that inform us about supernovae, some basic interpreta tions of such data, and an overview of t...

  20. Understanding vented gas explosions

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  1. Analysis of the internal explosion affecting building barriers

    Directory of Open Access Journals (Sweden)

    Jarosław Siwiński


    Full Text Available In this paper we considered the action of an internal explosion onto building barriers. Determination of the maximum peak pressure on the forehead of an internal wave explosion was presented on the basis of the analysis of reflected waves. Variability in time of the action of an internal explosion describes overpressure phase only. Load analysis of internal cargo detonation was carried out for the standard atmosphere undisturbed conditions. We developed the tabulated algorithm for determination of loadings taking into account the geometric characteristics of the building barriers and rooms in which the detonation occurs and parameters of explosion environment.[b]Keywords[/b]: civil engineering, explosive actions, internal explosion, concentrate explosive

  2. Inspection tester for explosives (United States)

    Haas, Jeffrey S.; Simpson, Randall L.; Satcher, Joe H.


    An inspection tester that can be used anywhere as a primary screening tool by non-technical personnel to determine whether a surface contains explosives. It includes a body with a sample pad. First and second explosives detecting reagent holders and dispensers are operatively connected to the body and the sample pad. The first and second explosives detecting reagent holders and dispensers are positioned to deliver the explosives detecting reagents to the sample pad. A is heater operatively connected to the sample pad.

  3. 75 FR 5545 - Explosives (United States)


    ... for classifying, labeling, and providing safety data sheets for explosives. By withdrawing this.... OSHA-S031-2006-0665 and OSHA-S-031)] RIN 1218-AC09 Explosives AGENCY: Occupational Safety and Health... the rulemaking to amend its Explosives and Blasting Agents Standard at 29 CFR 1910.109. OSHA is taking...

  4. New Mix Explosives for Explosive Welding (United States)

    Andreevskikh, Leonid


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

  5. Advances in impact resistance testing for explosion-proof electrical equipment

    Directory of Open Access Journals (Sweden)

    Pasculescu Vlad Mihai


    Full Text Available The design, construction and exploitation of electrical equipment intended to be used in potentially explosive atmospheres presents a series of difficulties. Therefore, the approach of these phases requires special attention concerning technical, financial and occupational health and safety aspects. In order for them not to generate an ignition source for the explosive atmosphere, such equipment have to be subjected to a series of type tests aiming to decrease the explosion risk in technological installations which operate in potentially explosive atmospheres. Explosion protection being a concern of researchers and authorities worldwide, testing and certification of explosion-proof electrical equipment, required for their conformity assessment, are extremely important, taking into account the unexpected explosion hazard due to potentially explosive atmospheres, risk which has to be minimized in order to ensure the occupational health and safety of workers, for preventing material losses and for decreasing the environmental pollution. Besides others, one of the type tests, which shall be applied, for explosion-proof electrical equipment is the impact resistance test, described in detail in EN 60079 which specifies the general requirements for construction, testing and marking of electrical equipment and Ex components intended for use in explosive atmospheres. This paper presents an analysis on the requirements of the impact resistance test for explosion-proof electrical equipment and on the possibilities to improve this type of test, by making use of modern computer simulation tools based on finite element analysis, techniques which are widely used nowadays in the industry and for research purposes.

  6. Explosives tester with heater (United States)

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


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

  7. Explosive Technology Group (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...

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

    National Research Council Canada - National Science Library

    J. J. L. du Plessis


    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...

  9. Explosions and static electricity

    DEFF Research Database (Denmark)

    Jonassen, Niels M


    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...

  10. Cell phone explosion. (United States)

    Atreya, Alok; Kanchan, Tanuj; Nepal, Samata; Pandey, Bhuwan Raj


    Cell phone explosions and resultant burn injuries are rarely reported in the scientific literature. We report a case of cell phone explosion that occurred when a young male was listening to music while the mobile was plugged in for charging. © The Author(s) 2015.

  11. Steam explosion studies review

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Moon Kyu; Kim, Hee Dong


    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)

  12. Melt Cast High Explosives

    Directory of Open Access Journals (Sweden)

    Stanisław Cudziło


    Full Text Available [b]Abstract[/b]. This paper reviews the current state and future developments of melt-cast high explosives. First the compositions, properties and methods of preparation of trinitrotoluene based (TNT conventional mixtures with aluminum, hexogen (RDX or octogen (HMX are described. In the newer, less sensitive explosive formulations, TNT is replaced with dinitroanisole (DNANDNANDNAN and nitrotriazolone (NTONTONTO, nitroguanidine (NG or ammonium perchlorate (AP are the replacement for RDRDX and HMX. Plasticized wax or polymer-based binder systems for melt castable explosives are also included. Hydroxyl terminated polybutadiene (HPTB is the binder of choice, but polyethylene glycol, and polycaprolactone with energetic plasticizers are also used. The most advanced melt-cast explosives are compositions containing energetic thermoplastic elastomers and novel highly energetic compounds (including nitrogen rich molecules in whose particles are nanosized and practically defect-less.[b]Keywords[/b]: melt-cast explosives, detonation parameters

  13. Jet noise recorded during discrete explosive eruptions (United States)

    Scarlato, P.; Sesterhenn, J.; Taddeucci, J.


    Most commonly, acoustic studies of explosive volcanic activity focus on the infrasonic range, as related to large volumetric changes mostly associated with the liberation of pressurized gas. However, there are multiple potential sources of sound that accompany explosive activity, expected to cover a broad range of frequencies. Among the audible range are several mechanisms, generating sound in high-velocity jets of gas or gas-particle mixture entering the atmosphere. This types of sound, well-documented and investigated in physics and engineering literature, has been so far mostly neglected in the study of explosive eruptions, due to the high energy content of the jet noise in the infrasonic regime, despite the potential it holds for parameterizing and understanding eruption processes. High-speed imaging of Strombolian and Vulcanian explosive eruptions at several volcanoes allowed the visualization of acoustic waves generated during the emission of the eruptive gas-pyroclast mixture. The waves, visible only when travelling within dilute gas/aerosol plumes, are thought to cause a temporary phase change in the travel medium. Image analysis allows direct measurement of the apparent (projected) trajectory, wavelength and travel velocity of the waves. Synchronized audio recording from the same eruptions include frequency contents in agreement with the observed waves. The general features of the observed waves are compatible with jet noise originated by the gas-pyroclast mixture entering the atmosphere, opening the way for future comparison with the results of numerical simulations of explosive eruptions, and possibly setting the basis for new acoustic monitoring tools for explosive eruptions.

  14. Chemical explosive stimulation

    Energy Technology Data Exchange (ETDEWEB)

    LaRocca, S.J.; McLamore, R.T.; Spencer, A.M. Jr.


    A safe, reliable chemical explosive fracturing process has been demonstrated and prototype equipment for its use has been successfully field tested.Called the Astro-Flow II process, it utilizes a highly energetic, hydrazine-based family of liquid explosives known as Astrolite. A unique property of these explosives is that they can be divided into 2 nonexplosive pumpable components that can be handled safely. The 2 components are pumped independently and simultaneously into the well and blended together downhole to form the explosive which is circulated in place or displaced into formation fractures. Explosive hazards to surface equipment and personnel are eliminated. Extensive testing of the physical and chemical stability of the mixed explosive indicates that the material can be reliable and safely used at elevated temperatures, pressures, and in the adverse chemical environment often found in deep oil and gas wells. These tests of prototype equipment proved that the 2 components could be independently pumped with precision and blended together to form the desired explosive formulation. How the process works is described.



    KOYUNCU, Hülya


    Explosives are used on a large scale byboth the military and by various civilian industries (e.g. mining, high-energymetalwork, and civil engineering). Explosives utilization contributes to the high environmentalcontamination. TNT(2,4,6-trinitrotoluene), RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine), HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) are found mainly in soils and surface waters; there havealso been cases of groundwater contamination. Most explosives are stable du...

  16. Aging of civil explosives (Poster)

    NARCIS (Netherlands)

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


    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

  17. Shock waves & explosions

    CERN Document Server

    Sachdev, PL


    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. Explosive Components Facility (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...

  19. Intermittent Explosive Disorder (United States)

    ... Headache Intermittent explosive disorder Symptoms & causes Diagnosis & treatment Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

  20. Parametric Explosion Spectral Model

    Energy Technology Data Exchange (ETDEWEB)

    Ford, S R; Walter, W R


    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.

  1. Ammonium nitrate explosion hazards

    Directory of Open Access Journals (Sweden)

    Negovanović Milanka


    Full Text Available Ammonium nitrate (AN primarily is used as a fertilizer but it is also very important compound in the production of industrial explosives. The application of ammonium nitrate in the production of industrial explosives was related with the early era of Nobel dynamite and widely increased with the appearance of blasting agents such as ANFO and Slurry, in the middle of the last Century. Throughout the world millions of tons of ammonium nitrate are produced annually and handled without incident. Although ammonium nitrate generally is used safely, accidental explosions involving AN have high impact resulting in loss of lives and destruction of property. The paper presents the basic properties of ammonium nitrate as well as hazards in handling of ammonium nitrate in order to prevent accidents. Several accidents with explosions of ammonium nitrate resulted in catastrophic consequences are listed in the paper as examples of non-compliance with prescribed procedures.

  2. Intermittent Explosive Disorder

    Directory of Open Access Journals (Sweden)

    Lut Tamam


    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.

  3. Modeling nuclear explosion (United States)

    Redd, Jeremy; Panin, Alexander


    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.

  4. Explosion suppression system (United States)

    Sapko, Michael J.; Cortese, Robert A.


    An explosion suppression system and triggering apparatus therefor are provided for quenching gas and dust explosions. An electrically actuated suppression mechanism which dispenses an extinguishing agent into the path ahead of the propagating flame is actuated by a triggering device which is light powered. This triggering device is located upstream of the propagating flame and converts light from the flame to an electrical actuation signal. A pressure arming device electrically connects the triggering device to the suppression device only when the explosion is sensed by a further characteristic thereof beside the flame such as the pioneer pressure wave. The light powered triggering device includes a solar panel which is disposed in the path of the explosion and oriented between horizontally downward and vertical. Testing mechanisms are also preferably provided to test the operation of the solar panel and detonator as well as the pressure arming mechanism.

  5. Polymeric binder for explosives (United States)

    Bissell, E. R.


    Chemical reaction for producing a polymer which can be mixed with explosives to produce a rigid material is discussed. Physical and chemical properties of polymers are described and chemical structure of the polymer is illustrated.

  6. Generation of low-frequency electric and magnetic fields during large- scale chemical and nuclear explosions

    Energy Technology Data Exchange (ETDEWEB)

    Adushkin, V.V. [Academy of Sciences, Moscow (Russian Federation). Inst. for Dynamics of the Geospheres; Dubinya, V.A.; Karaseva, V.A.; Soloviev, S.P.; Surkov, V.V. [Lawrence Livermore National Lab., CA (United States)


    We discuss the main parameters of the electric field in the surface layer of the atmosphere and the results of the investigations of the natural electric field variations. Experimental investigations of the electromagnetic field for explosions in air are presented. Electromagnetic signals generated by underground nuclear and chemical explosions are discussed and explosions for 1976--1991 are listed. Long term anomalies of the earth`s electromagnetic field in the vicinity of underground explosions were also investigated. Study of the phenomenon of the irreversible shock magnetization showed that in the zone nearest to the explosion the quasistatic magnetic field decreases in inverse proportion to the distance.

  7. Explosion containment device (United States)

    Benedick, William B.; Daniel, Charles J.


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

  8. Surface explosion cavities

    CERN Document Server

    Benusiglio, Adrien; Clanet, Christophe


    We present a fluid dynamics video on cavities created by explosions of firecrackers at the water free surface. We use three types of firecrackers containing 1, 1.3 and 5 g of flash powder. The firecrackers are held with their center at the surface of water in a cubic meter pool. The movies are recorded from the side with a high-speed video camera. Without confinement the explosion produces an hemispherical cavity. Right after the explosion this cavity grows isotropically, the bottom then stops while the sides continue to expand. In the next phase the bottom of the cavity accelerates backwards to the surface. During this phase the convergence of the flow creates a central jet that rises above the free surface. In the last part of the video the explosion is confined in a vertical open tube made of glass and of centimetric diameter. The explosion creates a cylindrical cavity that develops towards the free end of the tube. Depending on the charge, the cavity can either stop inside the tube or at its exit, but nev...

  9. 78 FR 64246 - Commerce in Explosives; List of Explosives Materials (United States)


    ... hydrocarbons. Explosive organic nitrate mixtures. Explosive powders. F Flash powder. ] Fulminate of mercury. Fulminate of silver. Fulminating gold. Fulminating mercury. Fulminating platinum. Fulminating silver. G... fulminate. Mercury oxalate. Mercury tartrate. Metriol trinitrate. Minol-2 . MMAN ; methylamine nitrate...



    Reed, J.


    An airblast prediction program for explosions, called BLASTO has been written for use with IBM-PC (or compatible) computers, to produce overpressure-distance curves for a variety of interactive input conditions. Several common units are allowed for each input, but calculation and output are in SI metric units. Explosion yield (chemical or nuclear) and ambient atmospheric pressure are used to generate a referenced 'Standard' overpressure-distance curve. Explosives may be point charges at any h...


    Directory of Open Access Journals (Sweden)

    Charles L. Mader


    Full Text Available Krakatoa exploded August 27, 1883 obliterating 5 square miles of land and leaving a crater 3.5 miles across and 200-300 meters deep. Thirty three feet high tsunami waves hit Anjer and Merak demolishing the towns and killing over 10,000 people. In Merak the wave rose to 135 feet above sea level and moved 100 ton coral blocks up on the shore.Tsunami waves swept over 300 coastal towns and villages killing 40,000 people. The sea withdrew at Bombay, India and killed one person in Sri Lanka.The tsunami was produced by a hydrovolcanic explosion and the associated shock wave and pyroclastic flows.A hydrovolcanic explosion is generated by the interaction of hot magma with ground water. It is called Surtseyan after the 1963 explosive eruption off Iceland. The water flashes to steam and expands explosively. Liquid water becoming water gas at constant volume generates a pressure of 30,000 atmospheres.The Krakatoa hydrovolcanic explosion was modeled using the full Navier-Stokes AMREulerian compressible hydrodynamic code called SAGE which includes the high pressure physics of explosions.The water in the hydrovolcanic explosion was described as liquid water heated by the magma to 1100 degree Kelvin or 19 kcal/mole. The high temperature water is an explosive with the hot liquid water going to a water gas. The BKW steady state detonation state has a peak pressure of 89 kilobars, a propagation velocity of 5900 meters/second and the water is compressed to 1.33 grams/cc.The observed Krakatoa tsunami had a period of less than 5 minutes and wavelength of less than 7 kilometers and thus rapidly decayed. The far field tsunami wave was negligible. The air shock generated by the hydrovolcanic explosion propagated around the world and coupled to the ocean resulting in the explosion being recorded on tide gauges around the world.

  12. Effects of Containment on Radionuclide Releases from Underground Nuclear Explosions (United States)

    Carrigan, C. R.; Sun, Y.


    Confirming the occurrence of an underground nuclear explosion can require capturing short-lived noble gas radioisotopes produced by the explosion, sometimes referred to as the "smoking gun" for nuclear explosion detection. It is well known that the radioisotopic distribution resulting from the detonation evolves with time in the explosion cavity. In effect, the explosion cavity or chimney behaves as a chemical reactor. As long as the parent and daughter radionuclides remain in a closed and well-mixed cavity, parameters, such as radioxenon isotopic ratios, can be calculated analytically from a decay-chain network model. When gases from the cavity migrate into the containment regime, consideration of a "leaky reactor" model is more appropriate. We consider several implications of such a leaky reactor model relevant to interpretations of gas samples from the subsurface during an on-site inspection that could potentially be carried out under the Comprehensive Nuclear Test Ban Treaty. Additionally, we have attempted to validate our leaky reactor model against atmospheric observations of radioactive xenon isotopes detected by radionuclide monitoring stations in Japan and Russia following the February 2013 DPRK underground nuclear explosion (Carrigan et al., 2016). While both model uncertainty and observational error are significant, our model of isotopic evolution appears to be in broad agreement with radionuclide observations, and for the first time links atmospheric measurements of radioxenon isotopic ratios to estimates of seismic yield. Carrigan et al., Scientific Reports 6, Article number: 23032 (2016) doi:10.1038/srep23032

  13. XIT Commercial Explosives Identification Tool (United States)


    Explosives Identification Tool (XIT) was supported by the Canadian Safety and Security Program ( CSSP ) which is led by Defence Research and Development...Explosives Training Unit, and Toronto Police Service, Explosives Disposal Unit. CSSP is a federally-funded program to strengthen Canada’s ability to

  14. Development of ammonium nitrate based explosives to optimize explosive properties and explosive welding parameters used during explosion cladding (United States)

    Hurley, Christoph

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

  15. Biodegradation of nitro-explosives. (United States)

    Kanekar, Pradnya; Dautpure, Premlata; Sarnaik, Seema


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

  16. Sublimation rates of explosive materials : method development and initial results.

    Energy Technology Data Exchange (ETDEWEB)

    Phelan, James M.; Patton, Robert Thomas


    Vapor detection of explosives continues to be a technological basis for security applications. This study began experimental work to measure the chemical emanation rates of pure explosive materials as a basis for determining emanation rates of security threats containing explosives. Sublimation rates for TNT were determined with thermo gravimetric analysis using two different techniques. Data were compared with other literature values to provide sublimation rates from 25 to 70 C. The enthalpy of sublimation for the combined data was found to be 115 kJ/mol, which corresponds well with previously reported data from vapor pressure determinations. A simple Gaussian atmospheric dispersion model was used to estimate downrange concentrations based on continuous, steady-state conditions at 20, 45 and 62 C for a nominal exposed block of TNT under low wind conditions. Recommendations are made for extension of the experimental vapor emanation rate determinations and development of turbulent flow computational fluid dynamics based atmospheric dispersion estimates of standoff vapor concentrations.

  17. Services Textbook of Explosives (United States)


    and shock effects is obtained by the use of ’primary’ (also known as ’initiatory’) explosives, among the most important of which are mercury fulminate ...Brown had discovered that compressed dry guncotton could be detonated by a mercury fulminate detonator, and a little later they found that compressed wet...of his powder (a mixture of mercury fulminate and potassium chlorate) enclosed in thin copper caps. This idea did not at once meet with the approval

  18. Explosives signatures and analysis (United States)

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


    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.

  19. Explosive Welding of Pipes (United States)

    Drennov, Oleg; Drennov, Andrey; Burtseva, Olga


    For connection by welding it is suggested to use the explosive welding method. This method is rather new. Nevertheless, it has become commonly used among the technological developments. This method can be advantageous (saving material and physical resources) comparing to its statical analogs (electron-beam welding, argon-arc welding, plasma welding, gas welding, etc.), in particular, in hard-to-reach areas due to their geographic and climatic conditions. Explosive welding of cylindrical surfaces is performed by launching of welded layer along longitudinal axis of construction. During this procedure, it is required to provide reliable resistance against radial convergent strains. The traditional method is application of fillers of pipe cavity, which are dense cylindrical objects having special designs. However, when connecting pipes consecutively in pipelines by explosive welding, removal of the fillers becomes difficult and sometimes impossible. The suggestion is to use water as filler. The principle of non-compressibility of liquid under quasi-dynamic loading is used. In one-dimensional gasdynamic and elastic-plastic calculations we determined non-deformed mass of water (perturbations, which are moving in the axial direction with sound velocity, should not reach the layer end boundaries for 5-7 circulations of shock waves in the radial direction). Linear dimension of the water layer from the zone of pipe coupling along axis in each direction is >= 2R, where R is the internal radius of pipe.

  20. Infrasound signals from the underground nuclear explosions of North Korea (United States)

    Che, Il-Young; Park, Junghyun; Kim, Inho; Kim, Tae Sung; Lee, Hee-Il


    We investigated the infrasound signals from seismic ground motions induced by North Korea's underground nuclear explosions, including the recent third explosion on 2013 February 12. For the third explosion, the epicentral infrasound signals were detected not only by three infrasound network stations (KSGAR, ULDAR and YAGAR) in South Korea but also by two nearby International Monitoring System infrasound stations, IS45 and IS30. The detectability of the signals was limited at stations located on the relatively east side of the epicentre, with large azimuth deviations due to very favourable atmospheric conditions for eastward propagation at stratospheric height in 2013. The stratospheric wind direction was the reverse of that when the second explosion was conducted in 2009 May. The source location of the epicentral infrasound with wave parameters determined at the multiple stations has an offset by about 16.6 km from the reference seismic location. It was possible to determine the infrasonic location with moderate accuracy by the correction of the azimuth deviation due to the eastward winds in the stratosphere. In addition to the epicentral infrasonic signals, diffracted infrasound signals were observed from the second underground nuclear explosion in 2009. The exceptional detectability of the diffracted infrasound was a consequence of the temporal formation of a thin atmospheric inversion layer over the ocean surface when the event occurred.

  1. Photoacoustic Sensing of Explosives (United States)


    weight (6 kg), and its power require- ments (24 W) allow for the high portability of the system. Laser vibrometer measurement, 2 meters from target...2515 P ar tic le v el oc ity (× 1 0 μ m /s ) −1 −2 2 0 1 −1 −2 2 0 1 −1 −2 2 0 1 The laser vibrometer and processing algorithms clearly...technique is depicted for a moving system. Note that the laser vibrometer measures the vibrations caused by the explosive vaporization process. At the same

  2. Laser machining of explosives (United States)

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


    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.

  3. Explosives detection for aviation security. (United States)

    Fainberg, A


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

  4. Introduction to High Explosives Science

    Energy Technology Data Exchange (ETDEWEB)

    Skidmore, Cary Bradford [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Preston, Daniel N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)


    These are a set of slides for educational outreach to children on high explosives science. It gives an introduction to the elements involved in this science: carbon, hydrogen, nitrogen, and oxygen. Combined, these form the molecule HMX. Many pictures are also included to illustrate explosions.

  5. Numerical Model for Hydrovolcanic Explosions. (United States)

    Mader, Charles; Gittings, Michael


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

  6. Microbial bioreporters of trace explosives. (United States)

    Shemer, Benjamin; Koshet, Ori; Yagur-Kroll, Sharon; Belkin, Shimshon


    Since its introduction as an explosive in the late 19th century, 2,4,6-trinitrotoluene (TNT), along with other explosive compounds, has left numerous environmental marks. One of these is widespread soil and water pollution by trace explosives in military proving grounds, manufacturing facilities, or actual battlefields. Another dramatic impact is that exerted by the millions of landmines and other explosive devices buried in large parts of the world, causing extensive loss of life, injuries, and economical damage. In this review we highlight recent advances in the design and construction of microbial bioreporters, molecularly engineered to generate a quantifiable dose-dependent signal in the presence of trace amounts of explosives. Such sensor strains may be employed for monitoring environmental pollution as well as for the remote detection of buried landmines. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Caribbean AIDS explosion examined. (United States)


    Homophobia, sex tourism, infidelity, and poverty are major factors causing a rapid explosion of AIDS and increasingly infecting women in the Caribbean. The region has the second largest incidence of AIDS in the world after Africa. The number of people with the HIV virus is likely greater than 500,000 and could be as high as 700,000, about twice the previously reported figures. Societal norms encourage homosexuals to have heterosexual relationships, and married men to have extramarital affairs, while poverty forces men and women to prostitution, often with tourists. In addition, a survey of 8100 school children in 4 English-speaking Caribbean islands revealed that 42% of the children had experienced sex before the age of 10 years; 62% had experienced it by age 12. This finding may reflect a high rate of child molestation in the region.

  8. Nucleosynthesis in stellar explosions

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  9. Mixing in explosions

    Energy Technology Data Exchange (ETDEWEB)

    Kuhl, A.L.


    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.

  10. Staging atmospheres

    DEFF Research Database (Denmark)

    Bille, Mikkel; Bjerregaard, Peter; Sørensen, Tim Flohr


    The article introduces the special issue on staging atmospheres by surveying the philosophical, political and anthropological literature on atmosphere, and explores the relationship between atmosphere, material culture, subjectivity and affect. Atmosphere seems to occupy one of the classic...

  11. Discriminating between explosions and earthquakes (United States)

    Cho, Kwang-Hyun


    Earthquake, explosion, and a nuclear test data are compared with forward modeling and band-pass filtered surface wave amplitude data for exploring methodologies to improve earthquake-explosion discrimination. The proposed discrimination method is based on the solutions of a double integral transformation in the wavenumber and frequency domains. Recorded explosion data on June 26, 2001 (39.212°N, 125.383°E) and October 30, 2001 (38.748°N, 125.267°E), a nuclear test on October 9, 2006 (41.275°N, 129.095°E), and two earthquakes on April 14, 2002 (39.207°N, 125.686°E) and June 7, 2002 (38.703°N, 125.638°E), all in North Korea, are used to discriminate between explosions and earthquakes by seismic wave analysis and numerical modeling. The explosion signal is characterized by first P waves with higher energy than that of S waves. Rg waves are clearly dominant at 0.05-0.5 Hz in the explosion data but not in the earthquake data. This feature is attributed to the dominant P waves in the explosion and their coupling with the SH components.

  12. Explosive signatures: Pre & post blast (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. Atmospheric pressure chemical ionization of explosives induced by soft X-radiation in ion mobility spectrometry: mass spectrometric investigation of the ionization reactions of drift gasses, dopants and alkyl nitrates. (United States)

    Riebe, Daniel; Erler, Alexander; Ritschel, Thomas; Beitz, Toralf; Löhmannsröben, Hans-Gerd; Beil, Andreas; Blaschke, Michael; Ludwig, Thomas


    A promising replacement for the radioactive sources commonly encountered in ion mobility spectrometers is a miniaturized, energy-efficient photoionization source that produce the reactant ions via soft X-radiation (2.8 keV). In order to successfully apply the photoionization source, it is imperative to know the spectrum of reactant ions and the subsequent ionization reactions leading to the detection of analytes. To that end, an ionization chamber based on the photoionization source that reproduces the ionization processes in the ion mobility spectrometer and facilitates efficient transfer of the product ions into a mass spectrometer was developed. Photoionization of pure gasses and gas mixtures containing air, N2 , CO2 and N2 O and the dopant CH2 Cl2 is discussed. The main product ions of photoionization are identified and compared with the spectrum of reactant ions formed by radioactive and corona discharge sources on the basis of literature data. The results suggest that photoionization by soft X-radiation in the negative mode is more selective than the other sources. In air, adduct ions of O2- with H2 O and CO2 were exclusively detected. Traces of CO2 impact the formation of adduct ions of O2- and Cl- (upon addition of dopant) and are capable of suppressing them almost completely at high CO2 concentrations. Additionally, the ionization products of four alkyl nitrates (ethylene glycol dinitrate, nitroglycerin, erythritol tetranitrate and pentaerythritol tetranitrate) formed by atmospheric pressure chemical ionization induced by X-ray photoionization in different gasses (air, N2 and N2 O) and dopants (CH2 Cl2 , C2 H5 Br and CH3 I) are investigated. The experimental studies are complemented by density functional theory calculations of the most important adduct ions of the alkyl nitrates (M) used for their spectrometric identification. In addition to the adduct ions [M + NO3 ]- and [M + Cl]- , adduct ions such as [M + N2 O2 ]- , [M + Br]- and [M

  14. Fire and explosion hazards to flora and fauna from explosives. (United States)

    Merrifield, R


    Deliberate or accidental initiation of explosives can produce a range of potentially damaging fire and explosion effects. Quantification of the consequences of such effects upon the surroundings, particularly on people and structures, has always been of paramount importance. Information on the effects on flora and fauna, however, is limited, with probably the weakest area lying with fragmentation of buildings and their effects on different small mammals. Information has been used here to gain an appreciation of the likely magnitude of the potential fire and explosion effects on flora and fauna. This is based on a number of broad assumptions and a variety of data sources including World War II bomb damage, experiments performed with animals 30-40 years ago, and more recent field trials on building break-up under explosive loading.

  15. Our Explosive Sun (United States)

    Brown, D. S.


    The Sun's atmosphere is a highly structured but dynamic place, dominated by the solar magnetic field. Hot charged gas (plasma) is trapped on lines of magnetic force that can snap like an elastic band, propelling giant clouds of material out into space. A range of ground-based and space-based solar telescopes observe these eruptions, particularly…

  16. Testing of Confining Pressure Impacton Explosion Energy of Explosive Materials (United States)

    Drzewiecki, Jan; Myszkowski, Jacek; Pytlik, Andrzej; Pytlik, Mateusz


    This paper presents the results of testing the explosion effects of two explosive charges placed in an environment with specified values of confining pressure. The aim of this study is to determine the impact of variable environmental conditions on the suitability of particular explosives for their use in the prevention of natural hazards in hard coal mining. The research results will contribute to improving the efficiency of currently adopted technologies of natural hazard prevention and aid in raising the level of occupational safety. To carry out the subject matter measurements, a special test stand was constructed which allows the value of the initial pressure inside the chamber, which constitutes its integral part, to be altered before the detonation of the charge being tested. The obtained characteristics of the pressure changes during the explosion of the analysed charge helped to identify the work (energy) which was produced during the process. The test results are a valuable source of information, opening up new possibilities for the use of explosives, the development of innovative solutions for the construction of explosive charges and their initiation.

  17. Fish Mortalities From Explosive Removal of Petroleum Platforms in the Gulf of Mexico 1993 to 1999 (NCEI Accession 0156750) (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data describe the first comprehensive study to quantitatively assess impacts of the explosive removal of offshore oil and gas structures on fish. The most...

  18. [Causation, prevention and treatment of dust explosion]. (United States)

    Dong, Maolong; Jia, Wenbin; Wang, Hongtao; Han, Fei; Li, Xiao-Qiang; Hu, Dahai


    With the development of industrial technology, dust explosion accidents have increased, causing serious losses of people's lives and property. With the development of economy, we should lay further emphasis on causation, prevention, and treatment of dust explosion. This article summarizes the background, mechanism, prevention, and treatment of dust explosion, which may provide some professional knowledge and reference for the treatment of dust explosion.

  19. Explosives mimic for testing, training, and monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, John G.; Durban, Matthew M.; Gash, Alexander E.; Grapes, Michael D.; Kelley, Ryan S.; Sullivan, Kyle T.


    Additive Manufacturing (AM) is used to make mimics for explosives. The process uses mixtures of explosives and matrices commonly used in AM. The explosives are formulated into a mixture with the matrix and printed using AM techniques and equipment. The explosive concentrations are kept less than 10% by wt. of the mixture to conform to requirements of shipping and handling.

  20. Microglass spheres in ammonium nitrate explosives


    Y. Kazakov; G. Turesheva; Olga Golovchenko; N. Bergeneva; R. Seisembayev


    Developed consisting the explosive ammonium nitrate, paraffin and mikrosteklosfer. Due to the input of the explosive paraffin increased water resistance of explosives to 60 minutes. By entering into the explosive mikrosteklosfers been improved caking indices, since steklomikrosfers and paraffin was formed seal between the granules of ammonium nitrate.

  1. Microglass spheres in ammonium nitrate explosives

    Directory of Open Access Journals (Sweden)

    Y. Kazakov


    Full Text Available Developed consisting the explosive ammonium nitrate, paraffin and mikrosteklosfer. Due to the input of the explosive paraffin increased water resistance of explosives to 60 minutes. By entering into the explosive mikrosteklosfers been improved caking indices, since steklomikrosfers and paraffin was formed seal between the granules of ammonium nitrate.

  2. Time-dependent buoyant puff model for explosive sources

    Energy Technology Data Exchange (ETDEWEB)

    Kansa, E.J.


    Several models exist to predict the time dependent behavior of bouyant puffs that result from explosions. This paper presents a new model that is derived from the strong conservative form of the conservation partial differential equations that are integrated over space to yield a coupled system of time dependent nonlinear ordinary differential equations. This model permits the cloud to evolve from an intial spherical shape not an ellipsoidal shape. It ignores the Boussinesq approximation, and treats the turbulence that is generated by the puff itself and the ambient atmospheric tubulence as separate mechanisms in determining the puff history. The puff cloud rise history was found to depend no only on the mass and initial temperature of the explosion, but also upon the stability conditions of the ambient atmosphere. This model was calibrated by comparison with the Roller Coaster experiments.

  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


    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. Explosive Blast Neuropathology and Seizures

    Directory of Open Access Journals (Sweden)

    S. Krisztian eKovacs


    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.

  5. Causes of the Cambrian Explosion

    National Research Council Canada - National Science Library

    M. Paul Smith; David A. T. Harper


    .... Recent hypotheses for the Cambrian explosion fall into three main categories: developmental/genetic, ecologic, and abiotic/environmental, with geochemical hypotheses forming an abundant and distinctive subset of the last...

  6. The classification of explosion-proof protected induction motor into adequate temperature and efficiency class (United States)

    Brinovar, Iztok; Srpčič, Gregor; Seme, Sebastijan; Štumberger, Bojan; Hadžiselimović, Miralem


    This article deals with the classification of explosion-proof protected induction motors, which are used in hazardous areas, into adequate temperature and efficiency class. Hazardous areas are defined as locations with a potentially explosive atmosphere where explosion may occur due to present of flammable gasses, liquids or combustible dusts (industrial plants, mines, etc.). Electric motors and electrical equipment used in such locations must be specially designed and tested to prevent electrical initiation of explosion due to high surface temperature and arcing contacts. This article presents the basic tests of three-phase explosion-proof protected induction motor with special emphasis on the measuring system and temperature rise test. All the measurements were performed with high-accuracy instrumentation and accessory equipment and carried out at the Institute of energy technology in the Electric machines and drives laboratory and Applied electrical engineering laboratory.

  7. Furball Explosive Breakout Test

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  8. Lidar Detection of Explosives Traces

    Directory of Open Access Journals (Sweden)

    Bobrovnikov Sergei M.


    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.

  9. Intraperitoneal explosion following gastric perforation. (United States)

    Mansfield, Scott K; Borrowdale, Roderick


    The object of this study is to report a rare case of explosion during laparotomy where diathermy ignited intraperitoneal gas from a spontaneous stomach perforation. Fortunately, the patient survived but the surgeon experienced a finger burn. A literature review demonstrates other examples of intraoperative explosion where gastrointestinal gases were the fuel source. Lessons learned from these cases provide recommendations to prevent this potentially lethal event from occurring. Copyright © 2012. Published by Elsevier B.V.

  10. Intraperitoneal explosion following gastric perforation

    Directory of Open Access Journals (Sweden)

    Scott K. Mansfield


    Full Text Available The object of this study is to report a rare case of explosion during laparotomy where diathermy ignited intraperitoneal gas from a spontaneous stomach perforation. Fortunately, the patient survived but the surgeon experienced a finger burn. A literature review demonstrates other examples of intraoperative explosion where gastrointestinal gases were the fuel source. Lessons learned from these cases provide recommendations to prevent this potentially lethal event from occurring.

  11. The Quiet Explosion (United States)


    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

  12. Molecular Outflows: Explosive versus Protostellar

    Energy Technology Data Exchange (ETDEWEB)

    Zapata, Luis A.; Rodríguez, Luis F.; Palau, Aina; Loinard, Laurent [Instituto de Radioastronomía y Astrofísica, UNAM, Apdo. Postal 3-72 (Xangari), 58089 Morelia, Michoacán, México (Mexico); Schmid-Burgk, Johannes [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121, Bonn (Germany)


    With the recent recognition of a second, distinctive class of molecular outflows, namely the explosive ones not directly connected to the accretion–ejection process in star formation, a juxtaposition of the morphological and kinematic properties of both classes is warranted. By applying the same method used in Zapata et al., and using {sup 12}CO( J = 2-1) archival data from the Submillimeter Array, we contrast two well-known explosive objects, Orion KL and DR21, to HH 211 and DG Tau B, two flows representative of classical low-mass protostellar outflows. At the moment, there are only two well-established cases of explosive outflows, but with the full availability of ALMA we expect that more examples will be found in the near future. The main results are the largely different spatial distributions of the explosive flows, consisting of numerous narrow straight filament-like ejections with different orientations and in almost an isotropic configuration, the redshifted with respect to the blueshifted components of the flows (maximally separated in protostellar, largely overlapping in explosive outflows), the very-well-defined Hubble flow-like increase of velocity with distance from the origin in the explosive filaments versus the mostly non-organized CO velocity field in protostellar objects, and huge inequalities in mass, momentum, and energy of the two classes, at least for the case of low-mass flows. Finally, all the molecular filaments in the explosive outflows point back to approximately a central position (i.e., the place where its “exciting source” was located), contrary to the bulk of the molecular material within the protostellar outflows.

  13. Hydrolysis of Miscanthus for bioethanol production using dilute acid presoaking combined with wet explosion pre-treatment and enzymatic treatment

    DEFF Research Database (Denmark)

    Sørensen, Annette; Teller, Philip Johan; Hilstrøm, Troels


    Miscanthus is a high yielding bioenergy crop. In this study we used acid presoaking, wet explosion, and enzymatic hydrolysis to evaluate the combination of the different pre-treatment methods for bioethanol production with Miscanthus. Acid presoaking is primarily carried out in order to remove...... xylose prior to wet explosion. The acid presoaking extracted 63.2% xylose and 5.2% glucose. Direct enzymatic hydrolysis of the presoaked biomass was found to give only low sugar yields of 24-26% glucose. Wet explosion is a pre-treatment method that combines wet-oxidation and steam explosion. The effect...... of wet explosion on non-presoaked and presoaked Miscanthus was investigated using both atmospheric air and hydrogen peroxide as the oxidizing agent. All wet explosion pre-treatments showed to have a disrupting effect on the lignocellulosic biomass, making the sugars accessible for enzymatic hydrolysis...

  14. Thickened aqueous slurry explosive composition

    Energy Technology Data Exchange (ETDEWEB)

    Craig, J.F.M.; Matts, T.C.; Seto, P.F.L.


    A thickened slurry explosive composition consists of water, inorganic oxidizing salt, fuel, and thickener wherein the thickener is a mixture of an unmodified guar gum and a hydroxypropyl-modified guar gum. The thickener mixture improves the stability and rheologic properties of the explosive. The preferred thickener mixture contains from 15 to 85% by weight of unmodified guar to 15 to 85% by weight of hydroxypropyl-modified guar and the composition preferably comprises 0.2% to 2.0% by weight of the thickener mixture. The thickener mixture is especially effective in explosive compositions sensitized with gas bubbles or with water-soluble organic nitrate for example, ethylene glycol mononitrate, propylene glycol mononitrate, ethanolamine nitrate, propanolamine nitrate, methylamine nitrate, ethylamine nitrate, ethylenediamine dinitrate, urea nitrate, or aniline nitrate. 14 claims.

  15. 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


    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.

  16. Estimation of Explosion Energy Yield at Chernobyl NPP Accident (United States)

    Pakhomov, Sergey A.; Dubasov, Yuri V.


    The value of the 133Xe/133mXe isometric activity ratio for the stationary regime of reactor work is about 35, and that for an instant fission (explosion) is about 11, which allowed estimation of the nuclear component of the instant (explosion) energy release during the NPP accident. Atmospheric xenon samples were taken at the trajectory of accident product transfers (in the Cherepovetz area); these samples were measured by a gamma spectrometer, and the 133Xe/133mXe ratio was determined as an average value of 22.4. For estimations a mathematic model was elaborated considering both the value of instant released energy and the schedule of reactor power change before the accident, as well as different fractionation conditions on the isobaric chain. Comparison of estimated results with the experimental data showed the value of the instant specific energy release in the Chernobyl NPP accident to be 2·105-2·106 J/Wt or 6·1014-6·1015 J (100-1,000 kt). This result is matched up to a total reactor power of 3,200 MWt. However this estimate is not comparable with the actual explosion scale estimated as 10t TNT. This suggests a local character of the instant nuclear energy release and makes it possible to estimate the mass of fuel involved in this explosion process to be from 0.01 to 0.1% of total quantity.

  17. Experiments in gasdynamics of explosions. (United States)

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


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

  18. Pulmonary contusion and hemothorax due to explosion

    National Research Council Canada - National Science Library

    Baeza-Herrera, Carlos; Sanjuán-Fabián, Héctor; Medellín-Sierra, Ulises Darío; Nájera-Garduño, Heladio; García-Cabello, Luis Manuel


    .... Such is the case of gunpowder explosive objects used during celebration holidays. We present a 14-year-old male who suffered a pulmonary contusion as a consequence of an explosion of "huevo de codorniz...

  19. Electrostatic Properties of Selected Personal Protective Equipment Regarding Explosion Hazard

    Directory of Open Access Journals (Sweden)

    Marcin Jachowicz


    Full Text Available In industries such as the mining, petrochemistry or power industries, personal protective equipment is often used in explosive atmospheres. What causes the occurrence of explosive hazards is ever-present in the work environment they include, electrostatic phenomena as well as the build-up of electrical charges on the surface of the protective equipment used. This paper presents the results of studies which were aimed at determining the fundamental electrostatic parameters of protective helmets as well as eye and face protection, surface resistance and the voltage of electrostatic fields. Examinations on the typical structure of the above mentioned equipment was conducted including the variable values of ambient humidity, which can occur in the working environment and with the use of various types of materials used to generate a charge. The adopted methods and testing equipment have been presented. Using the current, general requirements regarding the electrostatic properties of materials, the examined helmets and eye protection were assessed for their use in explosive atmospheres.

  20. Experimental Investigations of Multiphase Explosions (United States)

    Carney, Joel R.; Lightstone, James M.; McGrath, Thomas P.


    The addition of solid fuel particles to explosive formulations generally reduces the detonation velocity, but can enhance the blast performance if prompt combustion of the particles occurs in the detonation products and surrounding air early enough to support the shock. The degree to which fuel particles burn heavily depends on their dispersal throughout the explosion field and access to oxidizers. To distinguish the factors affecting the dispersal of fuel particles from those controlling their combustion, we began by analyzing the dispersal of equivalent mock inert particles. Solid glass spheres embedded in detonating small explosive charges were tracked using high-speed digital shadowgraphy. Two different particle sizes, 3 and 30 μm, and different mass fractions in the explosive compositions were considered. Shadowgraphs and pressure measurements were compared to the predictions of a newly developed multiphase numerical model. Reactive aluminum particles in the range of 1 to 120 μm in diameter were also analyzed. During the first 50 μs of the expansion, the general trend for both reactive and inert particles is for the smaller particles to expand near or beyond the leading shock wave to a greater extent than the larger particles. Expansion beyond the initial shock from the detonation is presumed to occur when particles agglomerate. The results are consistent with the predictions of the numerical models, highlighting the role of simple factors such as particle size and density in the early time expansion and mixing of fuels for enhanced blast applications.

  1. Explosive micro-bubble actuator

    NARCIS (Netherlands)

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


    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

  2. Risperidone and Explosive Aggressive Autism. (United States)

    Horrigan, Joseph P.; Barnhill, L. Jarrett


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

  3. Lead-free primary explosives (United States)

    Huynh, My Hang V.


    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.

  4. The Core-Collapse Supernova Explosion Mechanism (United States)

    Müller, Bernhard


    The explosion mechanism of core-collapse supernovae is a long-standing problem in stellar astrophysics. We briefly outline the main contenders for a solution and review recent efforts to model core-collapse supernova explosions by means of multi-dimensional simulations. Focusing on the neutrino-driven mechanism, we summarize currents efforts to predict supernova explosion and remnant properties.

  5. 30 CFR 7.100 - Explosion tests. (United States)


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Explosion tests. 7.100 Section 7.100 Mineral... Underground Coal Mines Where Permissible Electric Equipment is Required § 7.100 Explosion tests. (a) Test... agree. (ii) Remove all parts that do not contribute to the operation or ensure the explosion-proof...

  6. Explosion Power and Pressure Desensitization Resisting Property of Emulsion Explosives Sensitized by MgH2 (United States)

    Cheng, Yangfan; Ma, Honghao; Liu, Rong; Shen, Zhaowu


    Due to low detonation power and pressure desensitization problems that traditional emulsion explosives encounter in utilization, a hydrogen-based emulsion explosives was devised. This type of emulsion explosives is sensitized by hydrogen-containing material MgH2, and MgH2 plays a double role as a sensitizer and an energetic material in emulsion explosives. Underwater explosion experiments and shock wave desensitization experiments show that an MgH2 emulsion explosives has excellent detonation characteristics and is resistant to pressure desensitization. The pressure desensitization-resistant mechanism of MgH2 emulsion explosives was investigated using scanning electron microscopy.

  7. Cosmic Explosions, Life in the Universe, and the Cosmological Constant. (United States)

    Piran, Tsvi; Jimenez, Raul; Cuesta, Antonio J; Simpson, Fergus; Verde, Licia


    Gamma-ray bursts (GRBs) are copious sources of gamma rays whose interaction with a planetary atmosphere can pose a threat to complex life. Using recent determinations of their rate and probability of causing massive extinction, we explore what types of universes are most likely to harbor advanced forms of life. We use cosmological N-body simulations to determine at what time and for what value of the cosmological constant (Λ) the chances of life being unaffected by cosmic explosions are maximized. Life survival to GRBs favors Lambda-dominated universes. Within a cold dark matter model with a cosmological constant, the likelihood of life survival to GRBs is governed by the value of Λ and the age of the Universe. We find that we seem to live in a favorable point in this parameter space that minimizes the exposure to cosmic explosions, yet maximizes the number of main sequence (hydrogen-burning) stars around which advanced life forms can exist.

  8. Continuous flow, explosives vapor generator and sensor chamber (United States)

    Collins, Greg E.; Giordano, Braden C.; Sivaprakasam, Vasanthi; Ananth, Ramagopal; Hammond, Mark; Merritt, Charles D.; Tucker, John E.; Malito, Michael; Eversole, Jay D.; Rose-Pehrsson, Susan


    A novel liquid injection vapor generator (LIVG) is demonstrated that is amenable to low vapor pressure explosives, 2,4,6-trinitrotoluene and hexahydro-1,3,5-trinitro-1,3,5-triazine. The LIVG operates in a continuous manner, providing a constant and stable vapor output over a period of days and whose concentration can be extended over as much as three orders of magnitude. In addition, a large test atmosphere chamber attached to the LIVG is described, which enables the generation of a stable test atmosphere with controllable humidity and temperature. The size of the chamber allows for the complete insertion of testing instruments or arrays of materials into a uniform test atmosphere, and various electrical feedthroughs, insertion ports, and sealed doors permit simple and effective access to the sample chamber and its vapor.

  9. Requirements for estimation of doses from contaminants dispersed by a 'dirty bomb' explosion in an urban area

    DEFF Research Database (Denmark)

    Andersson, Kasper Grann; Mikkelsen, Torben; Astrup, Poul


    contributions from contaminants dispersed in the atmosphere after a ‘dirty bomb’ explosion. Conceptual methodologies are presented which describe the various dose components on the basis of knowledge of time-integrated contaminant air concentrations. Also the aerosolisation and atmospheric dispersion in a city...

  10. Sensitivity to friction for primary explosives. (United States)

    Matyáš, Robert; Šelešovský, Jakub; Musil, Tomáš


    The sensitivity to friction for a selection of primary explosives has been studied using a small BAM friction apparatus. The probit analysis was used for the construction of a sensitivity curve for each primary explosive tested. Two groups of primary explosives were chosen for measurement (a) the most commonly used industrially produced primary explosives (e.g. lead azide, tetrazene, dinol, lead styphnate) and (b) the most produced improvised primary explosives (e.g. triacetone triperoxide, hexamethylenetriperoxide diamine, mercury fulminate, acetylides of heavy metals). A knowledge of friction sensitivity is very important for determining manipulation safety for primary explosives. All the primary explosives tested were carefully characterised (synthesis procedure, shape and size of crystals). The sensitivity curves obtained represent a unique set of data, which cannot be found anywhere else in the available literature. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Spot test kit for explosives detection (United States)

    Pagoria, Philip F; Whipple, Richard E; Nunes, Peter J; Eckels, Joel Del; Reynolds, John G; Miles, Robin R; Chiarappa-Zucca, Marina L


    An explosion tester system comprising a body, a lateral flow membrane swab unit adapted to be removeably connected to the body, a first explosives detecting reagent, a first reagent holder and dispenser operatively connected to the body, the first reagent holder and dispenser containing the first explosives detecting reagent and positioned to deliver the first explosives detecting reagent to the lateral flow membrane swab unit when the lateral flow membrane swab unit is connected to the body, a second explosives detecting reagent, and a second reagent holder and dispenser operatively connected to the body, the second reagent holder and dispenser containing the second explosives detecting reagent and positioned to deliver the second explosives detecting reagent to the lateral flow membrane swab unit when the lateral flow membrane swab unit is connected to the body.

  12. Kamchatkan Volcanoes Explosive Eruptions in 2014 and Danger to Aviation (United States)

    Girina, Olga; Manevich, Alexander; Melnikov, Dmitry; Demyanchuk, Yury; Nuzhdaev, Anton; Petrova, Elena


    There are 30 active volcanoes in the Kamchatka, and several of them are continuously active. In 2014, three of the Kamchatkan volcanoes - Sheveluch, Karymsky and Zhupanovsky - had strong and moderate explosive eruptions. Moderate gas-steam activity was observing of Klyuchevskoy, Bezymianny, Avachinsky, Koryaksky, Gorely, Mutnovsky and other volcanoes. Strong explosive eruption of volcanoes is the most dangerous for aircraft because in a few hours or days in the atmosphere and the stratosphere can produce about several cubic kilometers of volcanic ash and aerosols. Ash plumes and the clouds, depending on the power of the eruption, the strength and wind speed, can travel thousands of kilometers from the volcano for several days, remaining hazardous to aircraft, as the melting temperature of small particles of ash below the operating temperature of jet engines. The eruptive activity of Sheveluch Volcano began since 1980 (growth of the lava dome) and is continuing at present. Strong explosive events of the volcano occurred in 2014: on January 08 and 12, May 12, September 24, October 02 and 28, November 16, 22 and 26, and December 05, 17, 26 and 29: ash plumes rose up to 9-12 km a.s.l. and extended more 900 km to the eastern and western directions of the volcano. Ashfalls occurred at Klyuchi Village (on January 12, June 11, and November 16). Activity of the volcano was dangerous to international and local aviation. Karymsky volcano has been in a state of explosive eruption since 1996. The moderate ash explosions of this volcano were noting during 2014: from March 24 till April 02; and from September 03 till December 10. Ash plumes rose up to 5 km a.s.l. and extended more 300 km mainly to the eastern directions of the volcano. Activity of the volcano was dangerous to local aviation. Explosive eruption of Zhupanovsky volcano began on June 06, 2014 and continues in January 2015 too. Ash explosions rose up to 8-10 km a.s.l. on June 19, September 05 and 07, October 11

  13. MMSReefish Study Databases from 1993-1999 field collections (SEC7-95-11 Fish Mortalities From Explosive Removal of Petroleum Platforms) (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Impacts of the Explosive Removal of Offshore Oil and Gas Structureson Fish Stocks in the Gulf of MexicoOffshore oil and gas platforms in the Gulf of Mexico (GOM)...

  14. Atmospheric Dispositifs

    DEFF Research Database (Denmark)

    Wieczorek, Izabela


    Through the coupling of dispositif with atmosphere this paper engages in a discussion of the atmospherics as both a form of knowledge and a material practice. In doing so the objective is to provide an inventory of tools and methodologies deployed in the construction of atmosphere understood......, the conceptual foundations and protocols for the production of atmosphere in architecture might be found beneath the surface of contemporary debates. In this context, the notion of atmospheric dispositif – illustrated through an oeuvre of the German architect Werner Ruhnau and its theoretical and historical...

  15. Studying stellar explosions with Athena (United States)

    O'Brien, P.; Jonker, P.

    Athena is the second large mission selected in the ESA Cosmic Vision plan. With its large collecting area, high spectral-energy resolution (X-IFU instrument) and impressive grasp (WFI instrument), Athena will truly revolutionise X-ray astronomy. The most prodigious sources of high-energy photons are often transitory in nature. Athena will provide the sensitivity and spectral resolution coupled with rapid response to enable the study of the dynamic sky. Potential sources include: distant Gamma-Ray Bursts to probe the reionisation epoch and find missing baryons in the cosmic web; tidal disruption events to reveal dormant supermassive and intermediate-mass black holes; and supernova explosions to understand progenitors and their environments. We illustrate Athenas capabilities and show how it will be able to constrain the nature of explosive transients including gas metallicity and dynamics.

  16. Ranchero Explosive Pulsed Power Experiments

    Energy Technology Data Exchange (ETDEWEB)

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


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

  17. 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


    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).

  18. Time-dependent buoyant puff model for explosive sources

    Energy Technology Data Exchange (ETDEWEB)

    Kansa, E.J.


    This paper presents a new model for explosive puff rise histories that is derived from the strong conservative form of the partial differential equations of mass, momenta, and total energy that are integrated over space to yield a coupled system of time dependent nonlinear ordinary differential equations (ODEs). By allowing the dimensions of the puff to evolve laterally and horizontally, the initial rising spherical shaped puff evolves into a rising ellipsoidal shaped mushroom cloud. This model treats the turbulence that is generated by the puff itself and the ambient atmospheric turbulence as separate mechanisms in determining the puff history. The puff rise history was found to depend not only upon the mass and initial temperature of the explosion, but also upon the local stability conditions of the ambient atmosphere through which the puff rises. This model was calibrated by comparison with the Roller Coaster experiments, ranging from unstable to very stable atmospheric conditions; the agreement of the model history curves with these experimental curves was within 10%.

  19. Free-surface microfluidics for detection of airborne explosives (United States)

    Meinhart, Carl; Piorek, Brian; Banerjee, Sanjoy; Lee, Seung Joon; Moskovits, Martin


    A novel microfluidic, remote-sensing, chemical detection platform has been developed for real-time sensing of airborne agents. The key enabling technology is a newly developed concept termed Free-Surface Fluidics (FSF), where one or more fluidic surfaces of a microchannel flow are confined by surface tension and exposed to the surrounding atmosphere. The result is a unique open channel flow environment that is driven by pressure through surface tension, and not subject to body forces, such as gravity. Evaporation and flow rates are controlled by microchannel geometry, surface chemistry and precisely-controlled temperature profiles. The free-surface fluidic architecture is combined with Surface-Enhanced Raman Spectroscopy (SERS) to allow for real-time profiling of atmospheric species and detection of airborne agents. The aggregation of SERS nanoparticles is controlled using microfluidics, to obtain dimer nanoparticle clusters at known streamwise positions in the microchannel. These dimers form SERS hot-spots, which amplify the Raman signal by 8 -- 10 orders of magnitude. Results indicate that explosive agents such as DNT, TNT, RDX, TATP and picric acid in the surrounding atmosphere can be readily detected by the SERS system. Due to the amplification of the SERS system, explosive molecules with concentrations of parts per trillion can be detected, even in the presence of interferent molecules having six orders of magnitude higher concentration.

  20. Explosives Removal from Munitions Wastewaters (United States)


    Rohm and Haas Company, Philadelphia, Pa., 19105 2 Background Generally, pollation in munitions plant waste water stems from washing and steam cleaning...290131 EXPLOSIVES REMOVAL FROM MUNITIONS WST- WATERS B. W. STEVENS, R. P. MCDONNELL ROHM. AND HAAS CO?*ANY, PHILAD2ELPHIA, PENNSYLVANIA R. K. PXDREN...operations. Waste water from a typical TNT manufacturing J21 plant may contain from 40 to 120 ppm of TNT and lesser aimounts of 2,4, DNT. K. Waste

  1. Shell and explosive hydrogen burning

    CERN Document Server

    Boeltzig, A; Cavanna, F; Cristallo, S; Davinson, T; Depalo, R; deBoer, R J; Di Leva, A; Ferraro, F; Imbriani, G; Marigo, P; Terrasi, F; Wiescher, M


    The nucleosynthesis of light elements, from helium up to silicon, mainly occurs in Red Giant and Asymptotic Giant Branch stars and Novae. The relative abundances of the synthesized nuclides critically depend on the rates of the nuclear processes involved, often through non-trivial reaction chains, combined with complex mixing mechanisms. In this review, we summarize the contributions made by LUNA experiments in furthering our understanding of nuclear reaction rates necessary for modeling nucleosynthesis in AGB stars and Novae explosions.

  2. Thermodynamic and Gasdynamic Aspects of a Boiling Liquid Expanding Vapour Explosion

    NARCIS (Netherlands)

    Xie, M.


    The risk of explosion due to rupture of a tank filled with pressurized liquefied gas (PLG) is one of the risks to be considered in the context of studies on tunnel safety. When a vessel containing liquid well above its boiling point at normal atmospheric pressure fails catastrophically a Boiling

  3. Nuclear Explosions 1945-1998

    Energy Technology Data Exchange (ETDEWEB)

    Bergkvist, Nils-Olov; Ferm, Ragnhild


    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)

  4. 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)


    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.

  5. The Martian highland paterae: Evidence for explosive volcanism on Mars (United States)

    Crown, David A.; Greeley, Ronald


    The Martian surface exhibits numerous volcanic landforms displaying great diversity in size, age, and morphology. Most research regarding Martian volcanology has centered around effusive basaltic volcanism, including analyses of individual lava flows, extensive lava plains, and large shield volcanoes. These studies were hindered by a lack of definitive morphologic criteria for the remote identification of ash deposits. Knowledge of the abundances, ages, and geologic settings of explosive volcanic deposits on Mars is essential to a comprehensive understanding of the evolution of the Martian surface, with implications for the evolution of the lithosphere and atmosphere as well as the histories of specific volcanic centers and provinces.

  6. Articulating Atmospheres

    DEFF Research Database (Denmark)

    Kinch, Sofie


    This paper presents an architectural approach to designing computational interfaces by articulating the notion of atmosphere in the field of interaction design. It draws upon the concept of kinesthetic interaction and a philosophical notion on atmosphere emphasizing the importance of bodily exper......” implications and qualities of the approach are identified through concrete examples of a design case, which also investigates the qualities and implications of addressing atmospheres both as design concern and user experience.......This paper presents an architectural approach to designing computational interfaces by articulating the notion of atmosphere in the field of interaction design. It draws upon the concept of kinesthetic interaction and a philosophical notion on atmosphere emphasizing the importance of bodily...... experience in space, presented as middle ground experience. In the field of HCI, middle ground experiences complete the unarticulated spectrum between designing for foreground of attention or background awareness. When “Articulating Atmospheres through Middle Ground Experiences in Interaction Design...

  7. Atmospheric electricity

    CERN Document Server

    Chalmers, J Alan


    Atmospheric Electricity brings together numerous studies on various aspects of atmospheric electricity. This book is composed of 13 chapters that cover the main problems in the field, including the maintenance of the negative charge on the earth and the origin of the charges in thunderstorms. After a brief overview of the historical developments of atmospheric electricity, this book goes on dealing with the general principles, results, methods, and the MKS system of the field. The succeeding chapters are devoted to some aspects of electricity in the atmosphere, such as the occurrence and d

  8. Atmospheric Neutrinos

    Directory of Open Access Journals (Sweden)

    Takaaki Kajita


    Full Text Available Atmospheric neutrinos are produced as decay products in hadronic showers resulting from collisions of cosmic rays with nuclei in the atmosphere. Electron-neutrinos and muon-neutrinos are produced mainly by the decay chain of charged pions to muons to electrons. Atmospheric neutrino experiments observed zenith angle and energy-dependent deficit of muon-neutrino events. It was found that neutrino oscillations between muon-neutrinos and tau-neutrinos explain these data well. This paper discusses atmospheric neutrino experiments and the neutrino oscillation studies with these neutrinos.

  9. Explosive dome eruptions modulated by periodic gas-driven inflation (United States)

    Johnson, Jeffrey B.; Lyons, John; Andrews, B. J.; Lees, J.M.


    Volcan Santiaguito (Guatemala) “breathes” with extraordinary regularity as the edifice's conduit system accumulates free gas, which periodically vents to the atmosphere. Periodic pressurization controls explosion timing, which nearly always occurs at peak inflation, as detected with tiltmeters. Tilt cycles in January 2012 reveal regular 26 ± 6 min inflation/deflation cycles corresponding to at least ~101 kg/s of gas fluxing the system. Very long period (VLP) earthquakes presage explosions and occur during cycles when inflation rates are most rapid. VLPs locate ~300 m below the vent and indicate mobilization of volatiles, which ascend at ~50 m/s. Rapid gas ascent feeds pyroclast-laden eruptions lasting several minutes and rising to ~1 km. VLPs are not observed during less rapid inflation episodes; instead, gas vents passively through the conduit producing no infrasound and no explosion. These observations intimate that steady gas exsolution and accumulation in shallow reservoirs may drive inflation cycles at open-vent silicic volcanoes.

  10. Estimation of body exposure to explosion. (United States)

    Oliver, William R; Baker, Andrew M; Powell, James D; Cotone, Chris M; Meeker, Jeffrey


    An ordnance-disposal expert was killed while disposing of a cache of explosives. The likely position of the body was reconstructed by modeling the explosion as an omnidirectional emission of particles from a model of the explosion site and noting the distribution of particles on a model of a human. The applications and limitations of this method in reconstructing the events and correlation with the injuries noted at autopsy are discussed.

  11. 75 FR 70291 - Commerce in Explosives; List of Explosive Materials (2010R-27T) (United States)


    ... hydrocarbons. Explosive organic nitrate mixtures. Explosive powders. F Flash powder. Fulminate of mercury. Fulminate of silver. Fulminating gold. Fulminating mercury. Fulminating platinum. Fulminating silver. G... fulminate. Mercury oxalate. Mercury tartrate. Metriol trinitrate. Minol-2 . MMAN ; methylamine nitrate...

  12. 77 FR 58410 - Commerce in Explosives; List of Explosive Materials (2012R-10T) (United States)


    ... hydrocarbons. Explosive organic nitrate mixtures. Explosive powders. F Flash powder. ] Fulminate of mercury. Fulminate of silver. Fulminating gold. Fulminating mercury. Fulminating platinum. Fulminating silver. G... fulminate. Mercury oxalate. Mercury tartrate. Metriol trinitrate. Minol-2 . MMAN ; methylamine nitrate...

  13. Shock Initiation of Damaged Explosives

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  14. High Explosives Research and Development (HERD) Facility (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...

  15. Explosives detection technology for commercial aviation security (United States)

    Schafrik, Robert E.


    The threat posed to commercial aviation by small, concealed plastic explosives is particularly onerous. Small amounts of these highly energetic explosives are difficult to reliably detect using current technologies. But they can cause significant damage to an aircraft that can result in the destruction of the aircraft, resulting in loss of life. The key issues regarding explosive detection technologies include: What methods can detect plastic explosives? How do these methods perform in practice? How can the different methods be best employed to counter the terrorist threat?

  16. Theoretical basis of explosion effects using al - granules in bulk explosives


    Dambov, Risto; Nikolic, Miroslav; Dambov, Ilija; Cacarov, Vladimir


    Use of bulk explosives such as AN-FO, heavy AN-FO, SLLURY and various Emulsions significantly improves explosive energy efficiency in the rock massif. Many operating engineers have the opportunity to examine and modify the technical characteristics of explosives and technologists especially, in the production of explosives where the main goal is improvement, the energy capacity by adding various components. The question is when is technically and economically most suitable to use ...

  17. Explosive transition in amorphous microwire (United States)

    Borisenko, I. Yu.; Tulin, V. A.


    An amorphous microwire in a glass shell offers a quick thermal response and can be rapidly heated to the crystallization point. When heated by a current pulse with a small amplitude and duration, the wire passes from the amorphous to microcrystalline state. The crystallization of the amorphous state may represent a slow or explosive process depending on the parameters of the pulse. In the latter case, the emission of electromagnetic waves (flash of light) and a sharp rise in the resistance are observed. The rate of propagation of the crystallization front in our experiments has been found to be about 1 m/s.

  18. Explosives detection using nanoporous coatings (United States)

    Pina, María P.; Pellejero, Ismael; Urbiztondo, Miguel; Sesé, Javier; Santamaría, J.


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

  19. Supernova Explosions Stay In Shape (United States)


    At a very early age, children learn how to classify objects according to their shape. Now, new research suggests studying the shape of the aftermath of supernovas may allow astronomers to do the same. A new study of images from NASA's Chandra X-ray Observatory on supernova remnants - the debris from exploded stars - shows that the symmetry of the remnants, or lack thereof, reveals how the star exploded. This is an important discovery because it shows that the remnants retain information about how the star exploded even though hundreds or thousands of years have passed. "It's almost like the supernova remnants have a 'memory' of the original explosion," said Laura Lopez of the University of California at Santa Cruz, who led the study. "This is the first time anyone has systematically compared the shape of these remnants in X-rays in this way." Astronomers sort supernovas into several categories, or "types", based on properties observed days after the explosion and which reflect very different physical mechanisms that cause stars to explode. But, since observed remnants of supernovas are leftover from explosions that occurred long ago, other methods are needed to accurately classify the original supernovas. Lopez and colleagues focused on the relatively young supernova remnants that exhibited strong X-ray emission from silicon ejected by the explosion so as to rule out the effects of interstellar matter surrounding the explosion. Their analysis showed that the X-ray images of the ejecta can be used to identify the way the star exploded. The team studied 17 supernova remnants both in the Milky Way galaxy and a neighboring galaxy, the Large Magellanic Cloud. For each of these remnants there is independent information about the type of supernova involved, based not on the shape of the remnant but, for example, on the elements observed in it. The researchers found that one type of supernova explosion - the so-called Type Ia - left behind relatively symmetric, circular

  20. The gas dynamics of explosions

    CERN Document Server

    Lee,\tJohn H S


    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.

  1. Power of TATP based explosives. (United States)

    Matyás, Robert; Selesovský, Jakub


    The power of various explosive mixtures based on triacetone triperoxide (3,3,6,6,9,9-hexamethyl-1,2,4,5,7,8-hexoxonane, TATP), ammonimum nitrate (AN), urea nitrate (UrN) and water (W), namely TATP/AN, oil/AN, TATP/UrN, TATP/W and TATP/AN/W, was studied using the ballistic mortar test. The ternary mixtures of TATP/AN/W have relatively high power in case of the low water contents. Their power decrease significantly with increasing the water content in the mixture to more than 30%.

  2. 27 CFR 70.445 - Commerce in explosives. (United States)


    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Commerce in explosives. 70... Cartridges, and Explosives § 70.445 Commerce in explosives. Part 55 of title 27 CFR contains the regulations..., explosives, (b) Permits for users who buy or transport explosives in interstate or foreign commerce, (c...

  3. 29 CFR 1926.902 - Surface transportation of explosives. (United States)


    ... of explosives shall be equipped with a fully charged fire extinguisher, in good condition. An... 29 Labor 8 2010-07-01 2010-07-01 false Surface transportation of explosives. 1926.902 Section 1926... Explosives § 1926.902 Surface transportation of explosives. (a) Transportation of explosives shall meet the...

  4. Urban atmospheres. (United States)

    Gandy, Matthew


    What is an urban atmosphere? How can we differentiate an 'atmosphere' from other facets of urban consciousness and experience? This essay explores some of the wider cultural, political, and philosophical connotations of atmospheres as a focal point for critical reflections on space and subjectivity. The idea of an 'affective atmosphere' as a distinctive kind of mood or shared corporeal phenomenon is considered in relation to recent developments in phenomenology, extended conceptions of agency, and new understandings of materialism. The essay draws in particular on the changing characteristics of air and light to reflect on different forms of sensory experience and their wider cultural and political connotations. The argument highlights some of the tensions and anomalies that permeate contemporary understandings of urban atmospheres.

  5. Pushing the Volcanic Explosivity Index to its limit and beyond: Constraints from exceptionally weak explosive eruptions at Kīlauea in 2008 (United States)

    Houghton, Bruce F.; Swanson, Don; Rausch, J.; Carey, R.J.; Fagents, S.A.; Orr, Tim R.


    Estimating the mass, volume, and dispersal of the deposits of very small and/or extremely weak explosive eruptions is difficult, unless they can be sampled on eruption. During explosive eruptions of Halema‘uma‘u Crater (Kīlauea, Hawaii) in 2008, we constrained for the first time deposits of bulk volumes as small as 9–300 m3 (1 × 104 to 8 × 105 kg) and can demonstrate that they show simple exponential thinning with distance from the vent. There is no simple fit for such products within classifications such as the Volcanic Explosivity Index (VEI). The VEI is being increasingly used as the measure of magnitude of explosive eruptions, and as an input for both hazard modeling and forecasting of atmospheric dispersal of tephra. The 2008 deposits demonstrate a problem for the use of the VEI, as originally defined, which classifies small, yet ballistic-producing, explosive eruptions at Kīlauea and other basaltic volcanoes as nonexplosive. We suggest a simple change to extend the scale in a fashion inclusive of such very small deposits, and to make the VEI more consistent with other magnitude scales such as the Richter scale for earthquakes. Eruptions of this magnitude constitute a significant risk at Kīlauea and elsewhere because of their high frequency and the growing number of “volcano tourists” visiting basaltic volcanoes.

  6. Space Weather: Linking Stellar Explosions to the Human Endeavor (United States)

    Knipp, Delores


    Arguably humans have flourished as a result of stellar explosions; we are, after all, stardust. Nonetheless, rapid technology advances of the last 200 years sometimes put society and individuals on a collision course with the natural variability of stellar and solar atmospheres. Human space exploration, routine satellite navigation system applications, aviation safety, and electric power grids are examples of such vulnerable endeavors. In this presentation I will outline how global society relies on ‘normal’ solar and stellar emissions, yet becomes susceptible to extremes of these emissions. The imprints of these astronomical-terrestrial interactions abound. In particular, I will highlight ways in which stellar/solar bursts link with our space-atmosphere-interaction region, producing multi-year patterns in cosmic ray detection, gorgeous aurora, and deep concern for good order and function of global community.



    Luchko, Ivan Andriiovych; Pashkov, Anatolii Pavlovych


    Dangerous factors at the handling ammonium nitrate explosives are covered. Dependence of influence of critical diameter for detonation on degree of compaction of the explosives is specified, causes of self-ignition of liquid explosive mixes are determined and measures according to their elimination are recommended.

  8. A structured approach to forensic study of explosions: The TNO Inverse Explosion Analysis tool

    NARCIS (Netherlands)

    Voort, M.M. van der; Wees, R.M.M. van; Brouwer, S.D.; Jagt-Deutekom, M.J. van der; Verreault, J.


    Forensic analysis of explosions consists of determining the point of origin, the explosive substance involved, and the charge mass. Within the EU FP7 project Hyperion, TNO developed the Inverse Explosion Analysis (TNO-IEA) tool to estimate the charge mass and point of origin based on observed damage

  9. High temperature two component explosive (United States)

    Mars, James E.; Poole, Donald R.; Schmidt, Eckart W.; Wang, Charles


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

  10. Geotechnical Aspects of Explosive Compaction

    Directory of Open Access Journals (Sweden)

    Mahdi Shakeran


    Full Text Available Explosive Compaction (EC is the ground modification technique whereby the energy released from setting off explosives in subsoil inducing artificial earthquake effects, which compact the soil layers. The efficiency of EC predominantly depends on the soil profile, grain size distribution, initial status, and the intensity of energy applied to the soil. In this paper, in order to investigate the geotechnical aspects, which play an important role in performance of EC, a database has been compiled from thirteen-field tests or construction sites around the world, where EC has been successfully applied for modifying soil. This research focuses on evaluation of grain size distribution and initial stability status of deposits besides changes of soil penetration resistance due to EC. Results indicated suitable EC performance for unstable and liquefiable deposits having particle sizes ranging from gravel to silty sand with less than 40% silt content and less than 10% clay content. However, EC is most effective in fine-to-medium sands with a fine content less than 5% and hydraulically deposited with initial relative density ranging from 30% to 60%. Moreover, it has been observed that EC can be an effective method to improve the density, stability, and resistance of the target soils.

  11. Advances IN Explosive Nuclear Astrophysics (United States)

    Lotay, Gavin


    Breathtaking results from the Planck satellite mission and Hubble space telescope have highlighted the key role modern Astronomy is playing for our understanding of Big Bang Cosmology. However, not so widely publicized is the similar wealth of observational data now available on explosive stellar phenomena, such as X-ray bursts, novae and Supernovae. These astronomical events are responsible for the synthesis of almost all the chemical elements we find on Earth and observe in our Galaxy, as well as energy generation throughout the cosmos. Regrettably, understanding the latest collection of observational data is severely hindered by the current, large uncertainties in the underlying nuclear physics processes that drive such stellar scenarios. In order to resolve this issue, it is becoming increasingly clear that there is a need to explore the unknown properties and reactions of nuclei away from the line of stability. Consequently, state-of-the-art radioactive beam facilities have become terrestrial laboratories for the reproduction of explosive astrophysical events. In this talk, both direct and indirect methods for studying key astrophysical reactions using radioactive beams will be discussed.

  12. Atmospheric Infancy

    DEFF Research Database (Denmark)

    Roald, Tone; Pedersen, Ida Egmose; Levin, Kasper


    In this article we establish intersubjective meaning-making in infancy as atmospheric. Through qualitative descriptions of five mother–infant dyads in a video-recorded, experimental setting when the infant is 4, 7, 10, and 13 months, we discovered atmospheric appearances with a developmental...... pattern of atmospheric variations. These appearances, we argue, are contextual and intersubjective monologues. The monologues are similar to what Daniel Stern describes with his concept of “vitality affects,” but they arise as a unified force that envelops the mother and child. As such, we present a new...

  13. Fire and explosion hazards of oil shale

    Energy Technology Data Exchange (ETDEWEB)


    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.

  14. Sensitivity to friction for primary explosives

    Energy Technology Data Exchange (ETDEWEB)

    Matyas, Robert, E-mail: [Institute of Energetic Materials, Faculty of Chemical Technology, University of Pardubice, Pardubice 532 10 (Czech Republic); Selesovsky, Jakub; Musil, Tomas [Institute of Energetic Materials, Faculty of Chemical Technology, University of Pardubice, Pardubice 532 10 (Czech Republic)


    Highlights: Black-Right-Pointing-Pointer The friction sensitivity of 14 samples of primary explosives was determined. Black-Right-Pointing-Pointer The same apparatus (small scale BAM) and the same method (probit analysis) was used. Black-Right-Pointing-Pointer The crystal shapes and sizes were documented with microscopy. Black-Right-Pointing-Pointer Almost all samples are less sensitive than lead azide, which is commercially used. Black-Right-Pointing-Pointer The organic peroxides (TATP, DADP, HMTD) are not as sensitive as often reported. - Abstract: The sensitivity to friction for a selection of primary explosives has been studied using a small BAM friction apparatus. The probit analysis was used for the construction of a sensitivity curve for each primary explosive tested. Two groups of primary explosives were chosen for measurement (a) the most commonly used industrially produced primary explosives (e.g. lead azide, tetrazene, dinol, lead styphnate) and (b) the most produced improvised primary explosives (e.g. triacetone triperoxide, hexamethylenetriperoxide diamine, mercury fulminate, acetylides of heavy metals). A knowledge of friction sensitivity is very important for determining manipulation safety for primary explosives. All the primary explosives tested were carefully characterised (synthesis procedure, shape and size of crystals). The sensitivity curves obtained represent a unique set of data, which cannot be found anywhere else in the available literature.

  15. Explosive Joining for Nuclear-Reactor Repair (United States)

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


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

  16. Forecasting volcanic explosions based on seismic quiescence (United States)

    Roman, D.; La Femina, P.; Rodgers, M.; Geirsson, H.; Tenorio, V.


    Volcanic eruptions are generally forecast based on strong increases in monitoring parameters such as seismicity or gas emissions above a relatively low background level. Because of this, forecasting individual explosions during an ongoing eruption, or at persistently restless volcanoes, is difficult as seismicity, gas emissions, and other indicators of unrest are already in a heightened state. Therefore, identification of short-term precursors to individual explosions at volcanoes already in heightened states of unrest, and an understanding of explosion trigger mechanisms, is important for the reduction of volcanic risk worldwide. Seismic and visual observations at Telica Volcano, Nicaragua, demonstrate that a) episodes of seismic quiescence reliably preceded explosions during an eruption in May 2011 and b) the duration of precursory quiescence and the energy released in the ensuing explosion were strongly correlated. Precursory seismic quiescence is interpreted as the result of sealing of shallow gas pathways, leading to pressure accumulation and eventual catastrophic failure of the system, culminating in an explosion. Longer periods of sealing and pressurization lead to greater energy release in the ensuing explosion. Near-real-time observations of seismic quiescence at restless or erupting volcanoes can thus be useful for both timely eruption warnings and for forecasting the energy of impending explosions.

  17. Some analytical methods for explosives: Part 2

    Energy Technology Data Exchange (ETDEWEB)

    Selig, W.


    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).

  18. Detection and dispersal of explosives by ants (United States)

    McFee, John E.; Achal, Steve; Faust, Anthony A.; Puckrin, Eldon; House, Andrew; Reynolds, Damon; McDougall, William; Asquini, Adam


    The ability of animals to detect explosives is well documented. Mammalian systems, insects and even single celled organisms have all been studied and in a few cases employed to detect explosives. This paper will describe the potential ability of ants to detect, disperse and possibly neutralize bulk explosives. In spring 2008 a team of DRDC and Itres scientists conducted experiments on detecting surface-laid and buried landmines, improvised explosive devices (IEDs) and their components. Measurements were made using state-of-the-art short wave and thermal infrared hyperspectral imagers mounted on a personnel lift. During one of the early morning measurement sessions, a wispy, long linear trail was seen to emanate several meters from piles of explosives that were situated on the ground. Upon close visual inspection, it was observed that ants had found the piles of explosives and were carrying it to their ant hill, a distance of almost 20 meters from the piles. Initial analysis of the hyperspectral images clearly revealed the trail to the ant hill of explosives, despite being present in quantities not visible to the unaided eye. This paper details these observations and discusses them in the context of landmine and IED detection and neutralization. Possible reasons for such behaviour are presented. A number of questions regarding the behaviour, many pertinent to the use of ants in a counter-landmine/IED role, are presented and possible methods of answering them are discussed. Anecdotal evidence from deminers of detection and destruction of explosives by ants are presented.

  19. 76 FR 8923 - Explosive Siting Requirements (United States)


    ... launch site in Title 14, Code of Federal Regulations (14 CFR) part 420. Part of the application for a... operational requirements of other regulatory regimes, they do not pose a risk of fire or explosion. Isolating... explosion due to the mixing of the two. In accordance with current DDESB and National Fire Protection...

  20. Characterization of mock high-explosive powder

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, C.R.; Dorsey, G.F.


    Analytical characterization and explosibility tests were made on a simulative high-explosive powder consisting of cyanuric acid, melamine, nitrocellulose, and tris-(..beta..-chloroethyl)-phosphate. Tests indicated that the powder presents no unusual safety or health hazards in isostatic-pressing and dry-machining operations.

  1. Explosion risks and consequences for tunnels

    NARCIS (Netherlands)

    Weerheijm, J.; Berg, A.C. van den


    Tunnel accidents with transports of dangerous goods may lead to explosions. Risk assessment for these accidents is complicated because of the low probability and the unknown, but disastrous effects expected. Especially the lack of knowledge on the strength of the explosion and the consequences for

  2. 33 CFR 401.67 - Explosive vessels. (United States)


    ... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Dangerous Cargo § 401.67 Explosive vessels. A vessel carrying explosives, either Government or commercial, as defined in the Dangerous Cargo Act of the United States and in the International Maritime Dangerous Goods Code, Class 1, Divisions 1.1 to 1.5 inclusive...

  3. 49 CFR 173.54 - Forbidden explosives. (United States)


    ... 49 Transportation 2 2010-10-01 2010-10-01 false Forbidden explosives. 173.54 Section 173.54 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... SHIPMENTS AND PACKAGINGS Definitions, Classification and Packaging for Class 1 § 173.54 Forbidden explosives...

  4. The St Marys fragmentation grenade explosion. (United States)

    Nocera, A


    The accidental explosion of a fragmentation grenade in a munitions factory at St Marys injured four workers, two critically. The prompt response by ambulances and physician-staffed helicopter emergency medical service prevented deaths, but the incident suggests lessons for the future handling of urban explosions.

  5. Hydrodynamics of Explosion Experiments and Models

    CERN Document Server

    Kedrinskii, Valery K


    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...

  6. [Explosion injuries - prehospital care and management]. (United States)

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


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

  7. Independence day explosion on lovers key. (United States)

    Harding, Brett A; Wolf, Barbara C


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

  8. Explosion interaction with water in a tube (United States)

    Homae, T.; Sugiyama, Y.; Wakabayashi, K.; Matsumura, T.; Nakayama, Y.


    As proposed and legislated in Japan, subsurface magazines have an explosive storage chamber, a horizontal passageway, and a vertical shaft for a vent. The authors found that a small amount of water on the floor of the storage chamber mitigated blast pressure remarkably. The mitigation mechanism has been examined more closely. To examine the effect of water, the present study assesses explosions in a transparent, square cross section, and a straight tube. A high-speed camera used to observe the tube interior. Blast pressure in and around the tube was also measured. Images obtained using the high-speed camera revealed that water inside the tube did not move after the explosion. Differences between cases of tubes without water and with water were unclear. Along with blast pressure measurements, these study results suggest that blast pressure mitigation by water occurs because of interaction between the explosion and the water near the explosion point.

  9. Local Explosion Monitoring using Rg (United States)

    O'Rourke, C. T.; Baker, G. E.


    Rg is the high-frequency fundamental-mode Rayleigh wave, which is only excited by near-surface events. As such, an Rg detection indicates that a seismic source is shallow, generally less than a few km depending on the velocity structure, and so likely man-made. Conversely, the absence of Rg can indicate that the source is deeper and so likely naturally occurring. We have developed a new automated method of detecting Rg arrivals from various explosion sources at local distances, and a process for estimating the likelihood that a source is not shallow when no Rg is detected. Our Rg detection method scans the spectrogram of a seismic signal for a characteristic frequency peak. We test this on the Bighorn Arch Seismic Experiment data, which includes earthquakes, active source explosions in boreholes, and mining explosions recorded on a dense network that spans the Bighorn Mountains and Powder River Basin. The Rg passbands used were 0.4-0.8 Hz for mining blasts and 0.8-1.2 Hz for borehole shots. We successfully detect Rg across the full network for most mining blasts. The lower-yield shots are detectable out to 50 km. We achieve methods that use cross-correlation to detect retrograde motion of the surface waves. Our method shows more complete detection across the network, especially in the Powder River Basin where Rg exhibits prograde motion that does not trigger the existing detector. We also estimate the likelihood that Rg would have been detected from a surface source, based on the measured P amplitude. For example, an event with a large P wave and no detectable Rg would have a high probability of being a deeper event, whereas we cannot confidently determine whether an event with a small P wave and no Rg detection is shallow or not. These results allow us to detect Rg arrivals, which indicate a shallow source, and to use the absence of Rg to estimate the likelihood that a source in a calibrated region is not shallow enough to be man-made.

  10. Explosion probability of unexploded ordnance: expert beliefs. (United States)

    MacDonald, Jacqueline Anne; Small, Mitchell J; Morgan, M G


    This article reports on a study to quantify expert beliefs about the explosion probability of unexploded ordnance (UXO). Some 1,976 sites at closed military bases in the United States are contaminated with UXO and are slated for cleanup, at an estimated cost of $15-140 billion. Because no available technology can guarantee 100% removal of UXO, information about explosion probability is needed to assess the residual risks of civilian reuse of closed military bases and to make decisions about how much to invest in cleanup. This study elicited probability distributions for the chance of UXO explosion from 25 experts in explosive ordnance disposal, all of whom have had field experience in UXO identification and deactivation. The study considered six different scenarios: three different types of UXO handled in two different ways (one involving children and the other involving construction workers). We also asked the experts to rank by sensitivity to explosion 20 different kinds of UXO found at a case study site at Fort Ord, California. We found that the experts do not agree about the probability of UXO explosion, with significant differences among experts in their mean estimates of explosion probabilities and in the amount of uncertainty that they express in their estimates. In three of the six scenarios, the divergence was so great that the average of all the expert probability distributions was statistically indistinguishable from a uniform (0, 1) distribution-suggesting that the sum of expert opinion provides no information at all about the explosion risk. The experts' opinions on the relative sensitivity to explosion of the 20 UXO items also diverged. The average correlation between rankings of any pair of experts was 0.41, which, statistically, is barely significant (p= 0.049) at the 95% confidence level. Thus, one expert's rankings provide little predictive information about another's rankings. The lack of consensus among experts suggests that empirical studies

  11. Nuclear explosives testing readiness evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Valk, T.C.


    This readiness evaluation considers hole selection and characterization, verification, containment issues, nuclear explosive safety studies, test authorities, event operations planning, canister-rack preparation, site preparation, diagnostic equipment setup, device assembly facilities and processes, device delivery and insertion, emplacement, stemming, control room activities, readiness briefing, arming and firing, test execution, emergency response and reentry, and post event analysis to include device diagnostics, nuclear chemistry, and containment. This survey concludes that the LLNL program and its supporting contractors could execute an event within six months of notification, and a second event within the following six months, given the NET group`s evaluation and the following three restraints: (1) FY94 (and subsequent year) funding is essentially constant with FY93, (2) Preliminary work for the initial event is completed to the historical sic months status, (3) Critical personnel, currently working in dual use technologies, would be recallable as needed.


    Directory of Open Access Journals (Sweden)

    Florin Adrian PĂUN


    Full Text Available Conveyor belts are used for a long period of time in the industry branches where potentially explosive atmospheres could occur. Dangerous phenomena which can be in direct connection with the use of conveyor belts are the ones regarding: - sparks influence over the coating layer and/or resistance internal structure of the stopped conveyor belt; - propagation of a flame along the length of a conveyor belt that was exposed to a energy source relative high like a fire or due to blockage of a conveyor belt as a result of the driving mechanism still operating, that generate a local heating of the conveyor belt in contact with the driving drum, rollers or any other heating source generated by friction. Determining the safety parameters characteristic of the conveyor belts by employing test methods allows assessment of the safety level as well as certification of their explosion protection quality when used in environments with explosion danger.

  13. Studies on formation of unconfined detonable vapor cloud using explosive means. (United States)

    Apparao, A; Rao, C R; Tewari, S P


    Certain organic liquid fuels like hydrocarbons, hydrocarbon oxides, when dispersed in air in the form of small droplets, mix with surrounding atmosphere forming vapor cloud (aerosol) and acquire explosive properties. This paper describes the studies on establishment of conditions for dispersion of fuels in air using explosive means resulting in formation of detonable aerosols of propylene oxide and ethylene oxide. Burster charges based on different explosives were evaluated for the capability to disperse the fuels without causing ignition. Parameters like design of canister, burster tube, burster charge type, etc. have been studied based on dispersion experiments. The detonability of the aerosol formed by the optimized burster charge system was also tested. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Understanding Vulcanian Explosions at Soufriere Hills Volcano, Montserrat, using Dilatometer Data (United States)

    Hidayat, D.; Sacks, S.; Linde, A.; Voight, B.; Widiwijayanti, C.; Elsworth, D.; Mattioli, G.; Malin, P.; Shalev, E.


    The collapse of the Soufriere Hills Volcano lava dome on Montserrat in July 2003, the largest such event worldwide in the historical record, was followed by several vulcanian explosions. Here we report on dilatometer data recording pressurisation the magma conduit for three of these explosions. Strain data for these explosions are characterized by contractive dilatation offset at all dilatometer sites, from 5.4 to 9.3 km from the crater. The data suggest an idealized vertical ellipsoidal source centered at about 2 km depth below the crater conduit. Contraction is indicated with overpressure ~10 MPa estimated for a source with semi- major and semi-minor length of 2000 m and 15 m, respectively. Barometer data show the influence of atmospheric pressure changes on the dilatometer strains, and give further information on eruption dynamics.

  15. Numerical modelling of the effect of using multi-explosives on the explosive forming of steel cones


    De Vuyst, T; Kong, K.; Djordjevic, N.; Vignjevic, R.; Campbell, JC; Hughes, K


    Modelling and analysis of underwater explosive forming process by using FEM and SPH formulation is presented in this work. The explosive forming of a steel cone is studied. The model setup includes a low carbon steel plate, plate holder, forming die as well as water and C4 explosive. The effect of multiple explosives on rate of targets deformation has been studied. Four different multi-explosives models have been developed and compared to the single explosive model. The formability of the ste...

  16. Explosive Volcanic Eruptions from Linear Vents on Earth, Venus and Mars: Comparisons with Circular Vent Eruptions (United States)

    Glaze, Lori S.; Baloga, Stephen M.; Wimert, Jesse


    Conditions required to support buoyant convective plumes are investigated for explosive volcanic eruptions from circular and linear vents on Earth, Venus, and Mars. Vent geometry (linear versus circular) plays a significant role in the ability of an explosive eruption to sustain a buoyant plume. On Earth, linear and circular vent eruptions are both capable of driving buoyant plumes to equivalent maximum rise heights, however, linear vent plumes are more sensitive to vent size. For analogous mass eruption rates, linear vent plumes surpass circular vent plumes in entrainment efficiency approximately when L(sub o) > 3r(sub o) owing to the larger entrainment area relative to the control volume. Relative to circular vents, linear vents on Venus favor column collapse and the formation of pyroclastic flows because the range of conditions required to establish and sustain buoyancy is narrow. When buoyancy can be sustained, however, maximum plume heights exceed those from circular vents. For current atmospheric conditions on Mars, linear vent eruptions are capable of injecting volcanic material slightly higher than analogous circular vent eruptions. However, both geometries are more likely to produce pyroclastic fountains, as opposed to convective plumes, owing to the low density atmosphere. Due to the atmospheric density profile and water content on Earth, explosive eruptions enjoy favorable conditions for producing sustained buoyant columns, while pyroclastic flows would be relatively more prevalent on Venus and Mars. These results have implications for the injection and dispersal of particulates into the planetary atmosphere and the ability to interpret the geologic record of planetary volcanism.

  17. Atmospheric neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Kajita, Takaaki [Research Center for Cosmic Neutrinos, Institute for Cosmic Ray Research, University of Tokyo, Kashiwa-no-ha 5-1-5, Kashiwa, Chiba 277-8582 (Japan)


    Neutrino oscillation was discovered through the study of atmospheric neutrinos. Atmospheric neutrinos are produced as decay products in hadronic showers resulting from collisions of cosmic rays with nuclei in the atmosphere. Electron neutrinos and muon neutrinos are produced mainly by the decay chain of charged pions to muons and electrons. Depending on the energy of the neutrinos, atmospheric neutrinos are observed as fully contained events, partially contained events and upward-going muon events. The energy range covered by these events is from a few hundred MeV to >1 TeV. Data from various experiments showed zenith angle- and energy-dependent deficit of {nu}{sub {mu}} events, while {nu}{sub e} events did not show any such effect. It was also shown that the {nu}{sub {mu}} survival probability obeys the sinusoidal function as predicted by neutrino oscillations. Two-flavour {nu}{sub {mu}} {r_reversible} {nu}{sub {tau}} oscillations, with sin{sup 2} 2{theta} > 0.90 and {delta}m{sup 2} in the region of 1.9 x 10{sup -3} to 3.0 x 10{sup -3} eV{sup 2}, explain all these data. Various detailed studies using high statistics atmospheric neutrino data excluded the alternative hypotheses that were proposed to explain the {nu}{sub {mu}} deficit.

  18. Fast Chromatographic Method for Explosive Profiling

    Directory of Open Access Journals (Sweden)

    Pierre-Hugues Stefanuto


    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. Dust explosion hazard in ITER: limiting oxygen concentration measurements of ITER-relevant dusts

    Energy Technology Data Exchange (ETDEWEB)

    Denkevits, A. [Forschungszentrum Karlsruhe (Germany)


    The work aim is to support inert-gas dilution mitigation methods proposed recently to prevent accidental explosions of dusts accumulated inside the ITER vacuum vessel during the machine operation. A standard method of 20-l-sphere is used to test 4 micron graphite dust and 1 micron tungsten dust to measure their Limiting Oxygen Concentration (LOC) values, below which no self-sustained flame propagation is possible in the dust cloud at any dust concentrations. The tested dust clouds are formed inside the 20-l spherical explosion bomb in nitrogen-diluted air atmospheres at normal initial conditions. The oxygen content in the pre-explosion atmospheres is varied from normal (about 21 vol. %) down to 9 vol. %. The tested dust cloud concentrations are 150-300 g/m{sup 3} of the graphite dust and 3000 g/m3 of the tungsten dust. The dust clouds are ignited with 2, 5, or 10 kJ igniters. The dependences of maximum overpressures and maximum rates of pressure rise generated in course of the dust cloud explosions are measured as functions of oxygen content in the pre-explosion atmospheres. The maximum overpressure generated by the graphite dust clouds ignited with 2 kJ reduces from 4 bar at normal oxygen content to 0.5 bar at 17 vol. % O2. In case of a stronger 10 kJ ignition the maximum overpressure is higher 0.5 bar down to 11 vol. % oxygen. The tungsten dust ignited by 5 kJ generate 4 bar overpressure in normal air. With reducing oxygen content the overpressure decreases to 0.5 bar at 13 vol. % oxygen. However, the observed regimes of the tungsten dust explosions seem to be overdriven under the tested conditions because of too high ignition energy (5 kJ) for rather a small combustion volume (20 l). Even the value of 15 vol. % oxygen can be considered as a conservative estimate of LOC for 1 micron tungsten dust. The results obtained indicate that only a weak dilution of accidental atmosphere in ITER vacuum vessel can suppress the dust explosions in case of severe accident

  20. Atmospheric thermodynamics

    CERN Document Server

    Iribarne, J V


    The thermodynamics of the atmosphere is the subject of several chapters in most textbooks on dynamic meteorology, but there is no work in English to give the subject a specific and more extensive treatment. In writing the present textbook, we have tried to fill this rather remarkable gap in the literature related to atmospheric sciences. Our aim has been to provide students of meteorology with a book that can playa role similar to the textbooks on chemical thermodynamics for the chemists. This implies a previous knowledge of general thermodynamics, such as students acquire in general physics courses; therefore, although the basic principles are reviewed (in the first four chapters), they are only briefly discussed, and emphasis is laid on those topics that will be useful in later chapters, through their application to atmospheric problems. No attempt has been made to introduce the thermodynamics of irreversible processes; on the other hand, consideration of heterogeneous and open homogeneous systems permits a...

  1. Conduit dynamics for Vulcanian explosions at Soufriere Hills Volcano, Montserrat, from strainmeter data (United States)

    Chardot, L.; Voight, B.; Stewart, R.; Linde, A. T.; Sacks, S. I.; Hidayat, D.; Fournier, N.


    The Soufrière Hills Volcano (SHV), Montserrat, has been erupting for over 14 years, with three semi-continuous periods of extrusion (~1-2 yr) separated by three long pauses. The third pause ended in late July 2008 but subsequent activity was discontinuous and comprised two short periods of extrusion with explosive activity. Vulcanian explosions at SHV in July and December 2008 and on 3 January 2009 were recorded on the CALIPSO array with Sacks-Evertson dilatometers. (The CALIPSO array contains specialized instruments in four strategically located ~200m-deep-boreholes installed to investigate the dynamics of the SHV magmatic system). The explosions resulted in clear, coherent strain-steps (amplitude range ca. ~2-140 nanostrain). We report here on observations of strainmeter and microbarometer data, which allow us to describe the evolution of conduit dynamics in the explosions. The strain data are corrected for air pressure effects, and compared to seismic observations, plume heights to >12 km, and mass erupted, in order to constrain conduit pressure, and the dynamics of the events. The explosions share many similarities and strain data for these explosions are (mainly) characterized by contractive dilatation offset at all sites, from 5.4 to 9.6 km from the crater. Barometer data show the influence of atmospheric pressure changes on the dilatometer strains and yield further information on eruption dynamics. The strain steps are correlated with explosion plume height and mass erupted and may be useful for rapid assessment of aviation hazards from airborne ash. The CALIPSO instrument network is supported by NSF.

  2. Metal explosion chambers: designing, manufacturing, application (United States)

    Stoyanovskii, O. I.; Zlobin, B. S.; Shtertser, A. A.; Meshcheryakov, Y. P.


    Designing of explosion chambers is based on research investigations of the chamber body stress-strain state, which is determined by numerical computation and experimentally by the strain gage technique. Studies show that chamber bottoms are the most loaded elements, and maximal stresses arise in chamber poles. Increasing the shell thickness around poles by welding-in an insert is a simple and saving way to solve this problem. There are structural solutions, enabling reliable hermetic closure and preventing leakage of detonation products from the chamber. Explosion chambers are employed in scientific research and in different industrial applications: explosive welding and hardening, synthesis of new materials, disposal of expired ammunition, and etc.

  3. Wave dynamics of electric explosion in solids (United States)

    Burkin, V. V.; Kuznetsova, N. S.; Lopatin, V. V.


    A mathematical model of an electric explosion is developed that consistently describes the expansion of the explosion channel with regard to the parameters of the discharge circuit of a high-voltage pulse generator, radiation, and propagation of stress waves in a solid. The dynamics of conversion of the stored energy to a wave and the formation of mechanical stresses due to electric explosion in a solid immersed in a liquid are considered. In the context of electro-discharge destruction of hard materials, the resulting stress field and the relationship between the discharge circuit parameters and characteristics of the wave are analyzed and the most efficient discharge modes are determined.

  4. The mathematical modeling of supernova explosion (United States)

    Denisov, A. A.; Koldoba, A. V.; Poveshchenko, Iu. A.; Popov, Iu. P.; Chechetkin, V. M.

    An essentially two-dimensional model of supernova explosion is developed, with emphasis on the role of rotation in the thermonuclear explosion process. Attention is given to a star with a carbon-oxygen core, which is transformed into a nickel core as a result of nuclear reaction. In this case, the development of thermal instability leads to the generation of a detonation wave propagating to the periphery of the star. Rapid rotation is found to produce a strong asymmetry of the hydrodynamic processs of the explosion.

  5. Water waves generated by underwater explosion

    CERN Document Server

    Mehaute, Bernard Le


    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

  6. On the Violence of High Explosive Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Tarver, C M; Chidester, S K


    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.

  7. Explosive Detection and Identification by PGNAA

    Energy Technology Data Exchange (ETDEWEB)

    E.H. Seabury; A.J. Caffrey


    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.

  8. Mechanism of unconfined dust explosions: Turbulent clustering and radiation-induced ignition. (United States)

    Liberman, Michael; Kleeorin, Nathan; Rogachevskii, Igor; Haugen, Nils Erland L


    It is known that unconfined dust explosions typically start off with a relatively weak primary flame followed by a severe secondary explosion. We show that clustering of dust particles in a temperature stratified turbulent flow ahead of the primary flame may give rise to a significant increase in the radiation penetration length. These particle clusters, even far ahead of the flame, are sufficiently exposed and heated by the radiation from the flame to become ignition kernels capable to ignite a large volume of fuel-air mixtures. This efficiently increases the total flame surface area and the effective combustion speed, defined as the rate of reactant consumption of a given volume. We show that this mechanism explains the high rate of combustion and overpressures required to account for the observed level of damage in unconfined dust explosions, e.g., at the 2005 Buncefield vapor-cloud explosion. The effect of the strong increase of radiation transparency due to turbulent clustering of particles goes beyond the state of the art of the application to dust explosions and has many implications in atmospheric physics and astrophysics.

  9. Analysis of the Explosive Internal Impact on the Barriers of Building Structures (United States)

    Siwiński, Jarosław; Stolarski, Adam


    Work issues concern the safety of construction in relation to the hazards arising from explosion of the explosive charge located inside the building. The algorithms proposed in the paper for determining the parameters of the overpressure wave resulting from the detonation of clustered explosive charges, determine the basis for numerical simulation analyzes. Determination of the maximum value of peak pressure on the wave forehead of an internal explosion is presented on the basis of reflected wave analysis. Changeability in time of the internal explosion action describes the overpressure phase only. The analysis of the load caused by the internal explosive charge detonation was carried out under conditions of the undisturbed standard atmosphere. A load determination algorithm has been developed, taking into account the geometrical characteristics of the building barriers and the rooms as well as the parameters of environment in which the detonation occurs. The way of taking into account the influence of venting surfaces, i.e. windows, doors, ventilation ducts, on the overpressure wave parameters, was presented. Discloses a method to take into account the effect of the surface relief, i.e. windows, doors, air ducts, pressure wave parameters. Modification of the method for explosive overpressure determination presented by Cormie, Smith, Mays (2009), was proposed in the paper. This modification was developed on the basis of substitute impulse analysis for multiple overpressure pulses. In order to take into account the pressure distribution of explosive gases on the barrier surface, the method of modification the relationship for determination the changeability over time and space of the pressure of explosive gases, was presented. For this purpose, the changeability of the pressure wave angles of incidence to the barrier and the distance of the explosive charge to any point on the surface of the barrier, was taken into account. Based on the developed procedure, the

  10. Alarming atmospheres

    DEFF Research Database (Denmark)

    Højlund, Marie; Kinch, Sofie


    Nurses working in the Neuro-Intensive Care Unit at Aarhus University Hospital lack the tools to prepare children for the alarming atmosphere they will enter when visiting a hospitalised relative. The complex soundscape dominated by alarms and sounds from equipment is mentioned as the main stressor...

  11. Atmospheric humidity (United States)

    Water vapor plays a critical role in earth's atmosphere. It helps to maintain a habitable surface temperature through absorption of outgoing longwave radiation, and it transfers trmendous amounts of energy from the tropics toward the poles by absorbing latent heat during evaporation and subsequently...

  12. 30 CFR 75.1314 - Sheathed explosive units. (United States)


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Sheathed explosive units. 75.1314 Section 75... explosive units. (a) A separate instantaneous detonator shall be used to fire each sheathed explosive unit. (b) Sheathed explosive units shall be primed and placed in position for firing only by a qualified...

  13. Detection of Nuclear Explosions Using Infrasound Techniques

    National Research Council Canada - National Science Library

    Christie, D. R; Kennett, B. L


    The performance of typical IMS infrasound monitoring stations has been examined in detail in order to evaluate the detection capability of the global network for regional and distant nuclear explosions...

  14. 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)


    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.

  15. Electronic cigarette explosions involving the oral cavity. (United States)

    Harrison, Rebecca; Hicklin, David


    The use of electronic cigarettes (e-cigarettes) is a rapidly growing trend throughout the United States. E-cigarettes have been linked to the risk of causing explosion and fire. Data are limited on the associated health hazards of e-cigarette use, particularly long-term effects, and available information often presents conflicting conclusions. In addition, an e-cigarette explosion and fire can pose a unique treatment challenge to the dental care provider because the oral cavity may be affected heavily. In this particular case, the patient's injuries included intraoral burns, luxation injuries, and alveolar fractures. This case report aims to help clinicians gain an increased knowledge about e-cigarette design, use, and risks; discuss the risk of spontaneous failure and explosion of e-cigarettes with patients; and understand the treatment challenges posed by an e-cigarette explosion. Copyright © 2016 American Dental Association. Published by Elsevier Inc. All rights reserved.

  16. Explosives Detection and Identification by PGNAA

    Energy Technology Data Exchange (ETDEWEB)

    E. H. Seabury; A. J. Caffrey


    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

  17. Highly explosive nanosilicon-based composite materials

    Energy Technology Data Exchange (ETDEWEB)

    Clement, D.; Diener, J.; Gross, E.; Kuenzner, N.; Kovalev, D. [Technical University of Munich, Physics Department, James-Franck-Str., 85747 Garching (Germany); Timoshenko, V.Yu. [Moscow State M.V. Lomonosov University, Physics Department, 119899 Moscow (Russian Federation)


    We present a highly explosive binary system based on porous silicon layers with their pores filled with solid oxidizers. The porous layers are produced by a standard electrochemical etching process and exhibit properties that are different from other energetic materials. Its production is completely compatible with the standard silicon technology and full bulk silicon wafers can be processed and therefore a large number of explosive elements can be produced simultaneously. The application-relevant parameters: the efficiency and the long-term stability of various porous silicon/oxidizer systems have been studied in details. Structural properties of porous silicon, its surface termination, the atomic ratio of silicon to oxygen and the chosen oxidizers were optimized to achieve the highest efficiency of the explosive reaction. This explosive system reveals various possible applications in different industrial fields, e.g. as a novel, very fast airbag igniter. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. Hamiltonian approach for explosive percolation. (United States)

    Moreira, A A; Oliveira, E A; Reis, S D S; Herrmann, H J; Andrade, J S


    We present a cluster growth process that provides a clear connection between equilibrium statistical mechanics and an explosive percolation model similar to the one recently proposed by D. Achlioptas [Science 323, 1453 (2009)]. We show that the following two ingredients are sufficient for obtaining an abrupt (first-order) transition in the fraction of the system occupied by the largest cluster: (i) the size of all growing clusters should be kept approximately the same, and (ii) the inclusion of merging bonds (i.e., bonds connecting vertices in different clusters) should dominate with respect to the redundant bonds (i.e., bonds connecting vertices in the same cluster). Moreover, in the extreme limit where only merging bonds are present, a complete enumeration scheme based on treelike graphs can be used to obtain an exact solution of our model that displays a first-order transition. Finally, the presented mechanism can be viewed as a generalization of standard percolation that discloses a family of models with potential application in growth and fragmentation processes of real network systems.

  19. Regional Seismic Methods of Identifying Explosions (United States)

    Walter, W. R.; Ford, S. R.; Pasyanos, M.; Pyle, M. L.; Hauk, T. F.


    A lesson from the 2006, 2009 and 2013 DPRK declared nuclear explosion Ms:mb observations is that our historic collection of data may not be representative of future nuclear test signatures (e.g. Selby et al., 2012). To have confidence in identifying future explosions amongst the background of other seismic signals, we need to put our empirical methods on a firmer physical footing. Here we review the two of the main identification methods: 1) P/S ratios and 2) Moment Tensor techniques, which can be applied at the regional distance (200-1600 km) to very small events, improving nuclear explosion monitoring and confidence in verifying compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Amplitude ratios of seismic P-to-S waves at sufficiently high frequencies (~>2 Hz) can identify explosions among a background of natural earthquakes (e.g. Walter et al., 1995). However the physical basis for the generation of explosion S-waves, and therefore the predictability of this P/S technique as a function of event properties such as size, depth, geology and path, remains incompletely understood. Calculated intermediate period (10-100s) waveforms from regional 1-D models can match data and provide moment tensor results that separate explosions from earthquakes and cavity collapses (e.g. Ford et al. 2009). However it has long been observed that some nuclear tests produce large Love waves and reversed Rayleigh waves that complicate moment tensor modeling. Again the physical basis for the generation of these effects from explosions remains incompletely understood. We are re-examining regional seismic data from a variety of nuclear test sites including the DPRK and the former Nevada Test Site (now the Nevada National Security Site (NNSS)). Newer relative amplitude techniques can be employed to better quantify differences between explosions and used to understand those differences in term of depth, media and other properties. We are also making use of the Source Physics

  20. Effects of Explosions in Underground Magazines (United States)


    values of confined explosion gas pressure for PETN in air at sea level.. 23 2.3 An example of the scaling procedure employed to predict peak pressures in...compared to -thoso currently eowployed in the 1980 Department of )fise, O0D) - Amunititon and Explosivo Safety Standards (Refotetce 1). The details are...comparisons of Proctor’s (1974, Reference 5) theoretical predictions with experimontal data for TNT and PETN explosives. Stromsoo (Reference 8) calculated

  1. Non-shock initiation of explosives

    National Research Council Canada - National Science Library

    Asay, B. W


    ... explosives. Before 1942, explosives were used in munitions and commercial pursuits that demanded proper chemistry and confinement for the necessary effect, but little else. The needs and requirements of the Manhattan project were of a much more precise and specific nature. Spatial and temporal specifications were reduced from centimeters and milliseconds to micrometers and nanoseconds. New theory and computational tools were required along with a raft of new experimental techniques and novel ways of interpreting...

  2. Weapons Experiments Division Explosives Operations Overview

    Energy Technology Data Exchange (ETDEWEB)

    Laintz, Kenneth E. [Los Alamos National Laboratory


    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.

  3. Explosively Bonded Gun Tube Liner Development (United States)


    some concern was the occasional appearance of iron-Ta intermetallics near the liner-steel interface. This is a brittle phase and subject to...Montgomery JS, de Rosset WS. Examination of intermetallic phases and residual stresses resulting from explosive bonding of refractory metal gun tube...caliber smoothbore gun tube. The metallic bond produced by explosive bonding is extremely strong and presumably would keep the liner in place. In Phase

  4. Grain-scale Dynamics in Explosives

    Energy Technology Data Exchange (ETDEWEB)

    Reaugh, J E


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

  5. What factors control superficial lava dome explosivity? (United States)

    Boudon, Georges; Balcone-Boissard, Hélène; Villemant, Benoît; Morgan, Daniel J


    Dome-forming eruption is a frequent eruptive style and a major hazard on numerous volcanoes worldwide. Lava domes are built by slow extrusion of degassed, viscous magma and may be destroyed by gravitational collapse or explosion. The triggering of lava dome explosions is poorly understood: here we propose a new model of superficial lava-dome explosivity based upon a textural and geochemical study (vesicularity, microcrystallinity, cristobalite distribution, residual water contents, crystal transit times) of clasts produced by key eruptions. Superficial explosion of a growing lava dome may be promoted through porosity reduction caused by both vesicle flattening due to gas escape and syn-eruptive cristobalite precipitation. Both processes generate an impermeable and rigid carapace allowing overpressurisation of the inner parts of the lava dome by the rapid input of vesiculated magma batches. The relative thickness of the cristobalite-rich carapace is an inverse function of the external lava dome surface area. Explosive activity is thus more likely to occur at the onset of lava dome extrusion, in agreement with observations, as the likelihood of superficial lava dome explosions depends inversely on lava dome volume. This new result is of interest for the whole volcanological community and for risk management.

  6. Statistical estimation of loads from gas explosions

    Energy Technology Data Exchange (ETDEWEB)

    Hoeiset, Stian


    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.

  7. Experimental Explosive Characterization for Counterterrorist Investigation (United States)

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


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

  8. Thermal explosion in oscillating ambient conditions (United States)

    Novozhilov, Vasily


    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. PMID:27443235

  9. Solid Rocket Launch Vehicle Explosion Environments (United States)

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


    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. Research on a Sudden Explosion and its Environmental Impact (United States)

    Ye, Maosheng; Ma, Hui; Ni, Qingwei


    A sudden blast was chosen as the studied topic. Also, one computer based virtual experimentation was used to estimate the dimensional impact of initial pollutant plume from blasts. Self-made method using Mathcad code was used to generate the output for the period of the first tenth of a second (1deci-second) to 1minute (60s) of the blast at the point source. It also depicted long-range air pollution travel within the first 1 to 10 minutes. In the case study, it assumed an average directional diffusivity of 1720 m2s-1 which is about 25 per cent of the average generated speed of common explosives. The newly developed model revealed a plume cloud impact of 6.8×107µgm-3 in the first 1millisecond (0.01s) which decayed suddenly to a value of 1.7×107µgm-3 in the first 1decisecond (0.1s). The impact concentration at the point source by the end of the first second (1.0s) was 3.2×105µgm-3 which implied a 99.5% sudden decay when compared to 0.01s concentration value at the emission point source. Computerized experiments observed that air pollutants release from explosives/blasts were dispersed into the atmosphere in the first few seconds by forceful injection instead of by gradual dispersion as is the case with normal air pollutants plume releases.

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


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


    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...

  12. Atmospheric materiality

    DEFF Research Database (Denmark)

    Wieczorek, Izabela


    A disjunction between the material and the immaterial has been at the heart of the architectural debate for decades. In this dialectic tension, the notion of atmosphere which increasingly claims attention in architectural discourse seems to be parallactic, leading to the re-evaluation of perceptual...... experience and, consequently, to the conceptual and methodological shifts in the production of space, and hence in the way we think about materiality. In this context, architectural space is understood as a contingent construction – a space of engagement that appears to us as a result of continuous...... and complex interferences revealed through our perception; ‘the atmospheric’ is explored as a spatial and affective quality as well as a sensory background, and materiality as a powerful and almost magical agency in shaping of atmosphere. Challenging existing dichotomies and unraveling intrinsic...

  13. Explosive Activity at Tungurahua Volcano: Analysis of Seismic and Infrasonic Data from 2006 - 2011 (United States)

    Steele, A. L.; Ruiz, M. C.; Lyons, J. J.


    propagated through the atmosphere and into the earth (η = acoustic energy/seismic energy), calculated from discrete explosions, is used to infer temporal changes in shallow conduit conditions across and between phases of activity. Typically, values in explosion VASR during the 5 years display relatively high acoustic partitioning (η ~ 1-1000), which we relate to a moderately open vent system. However, we attribute lower VASR during the early stages of May-July 2010 to an initially, partially choked conduit, an alteration in volcanic conditions that is reflected within the anomalous results of other statistical tests applied to this period of activity. Through continuous explosive degassing, we envision that the plug is eventually cleared, as an increase in explosion VASR is observed towards the latter stages of the active phase. Several statistical techniques applied to the 2006-2011 explosion dataset at Tungurahua were useful for revealing patterns in eruptive behavior, with statistical differences between periods of activity identifying a temporal evolution in eruption mechanism. Continued monitoring and a comparison of Tungurahua data with similar explosive records at other volcanoes, will lead to improved tools for analyzing sequences of explosive eruptions and more robust forecasting methods.

  14. Explosions in Majestic Spiral Beauties (United States)


    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

  15. Analysis of GOSAT XCO2 in explosive volcanic plumes (United States)

    Popp, Christoph; Andrews, Benjamin J.; Carn, Simon A.; Chance, Kelly; Cottrell, Elizabeth; Schwandner, Florian M.


    In this study, we analyze columnar averaged dry air mole fraction of CO2 (XCO2) in volcanic gas plumes after major eruptions using space-borne near-infrared measurements from the Japanese Greenhouse gas Observing SATellite (GOSAT). Volcanic emissions are assumed to dominate the flux from the deep Earth to the surface but those global emissions as well as the partitioning between eruptive and non-eruptive emissions are to date highly uncertain. Satellite measurements are an indispensable complement to ground-based measurements of volcanic CO2 emissions because they are performed globally and regularly and they therefore have the potential to significantly broaden our knowledge of volcanic CO2 releases. However, the remote sensing of volcanic CO2 is challenging for various reasons, including the increasingly high atmospheric background, relatively coarse spatial resolution and/or sampling, and scattering effects of aerosols and clouds. We mined existing standard product level 2 GOSAT XCO2 data sets for a volcanic CO2 signal in the gas plumes of the largest volcanic eruptions since GOSAT's launch in 2009. These eruptions include the Volcanic Explosivity Index (VEI) 4 events of Sarychev Peak (Kuril Islands, Russia) in June 2009, Nabro (Ethiopia) in June 2011, and Puyehue-Cordon Caulle (Chile) in June 2011. GOSAT background and plume soundings are distinguished using corresponding Ozone Monitoring Instrument (OMI) SO2 retrievals taking advantage of the usually low atmospheric SO2 background abundance. A volcanic CO2 signal in the GOSAT products can subsequently be found by comparing GOSAT XCO2 for the plume and background soundings. Possible XCO2 enhancements in the volcanic plumes are converted to an estimated CO2 release of the investigated eruptions. Based on this analysis, the current capabilities and added value of GOSAT TANSO-FTS to detect and quantify CO2 emissions from explosive volcanism are outlined.

  16. 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.


    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.

  17. Finite-difference numerical simulations of underground explosion cavity decoupling (United States)

    Aldridge, D. F.; Preston, L. A.; Jensen, R. P.


    Earth models containing a significant portion of ideal fluid (e.g., air and/or water) are of increasing interest in seismic wave propagation simulations. Examples include a marine model with a thick water layer, and a land model with air overlying a rugged topographic surface. The atmospheric infrasound community is currently interested in coupled seismic-acoustic propagation of low-frequency signals over long ranges (~tens to ~hundreds of kilometers). Also, accurate and efficient numerical treatment of models containing underground air-filled voids (caves, caverns, tunnels, subterranean man-made facilities) is essential. In support of the Source Physics Experiment (SPE) conducted at the Nevada National Security Site (NNSS), we are developing a numerical algorithm for simulating coupled seismic and acoustic wave propagation in mixed solid/fluid media. Solution methodology involves explicit, time-domain, finite-differencing of the elastodynamic velocity-stress partial differential system on a three-dimensional staggered spatial grid. Conditional logic is used to avoid shear stress updating within the fluid zones; this approach leads to computational efficiency gains for models containing a significant proportion of ideal fluid. Numerical stability and accuracy are maintained at air/rock interfaces (where the contrast in mass density is on the order of 1 to 2000) via a finite-difference operator "order switching" formalism. The fourth-order spatial FD operator used throughout the bulk of the earth model is reduced to second-order in the immediate vicinity of a high-contrast interface. Current modeling efforts are oriented toward quantifying the amount of atmospheric infrasound energy generated by various underground seismic sources (explosions and earthquakes). Source depth and orientation, and surface topography play obvious roles. The cavity decoupling problem, where an explosion is detonated within an air-filled void, is of special interest. A point explosion

  18. 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


    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.

  19. Thermal Impulse Sensors for use in Explosions (United States)

    Eilers, Hergen; Gunawidjaja, Ray; Anderson, Benjamin


    We have developed temperature and thermal impulse (temperature and duration) sensors for use in explosive fireballs. These sensors are seeded into an explosive fireball and record temperature and duration via morphological phase changes that are optically probed. The thermal impulse sensors include two sensor materials with different phase transition kinetics, and may include a reference material which does not undergo temperature-induced phase changes, and can aid in the optical analysis. Analyzing the sensor materials allows us to determine heating temperature and heating duration of an explosion. The temperature sensors and thermal impulse sensors were recently tested and showed promising results. However, we found that the different components of the thermal impulse sensors tend to get separated during the explosion. We are now evaluating several approaches for redesigning our thermal impulse sensors so that the components remain together during the explosion. These approaches include a core/shell assembly, crosslinking, and co-synthesis. The integrity of the chemically bonded components is evaluated by subjecting the sensors to dispersing forces, while temperature-dependent phase changes of these sensors are assessed by rapid heating using a CO2 laser.

  20. GT0 Explosion Sources for IMS Infrasound Calibration: Charge Design and Yield Estimation from Near-source Observations (United States)

    Gitterman, Y.; Hofstetter, R.


    Three large-scale on-surface explosions were conducted by the Geophysical Institute of Israel (GII) at the Sayarim Military Range, Negev desert, Israel: about 82 tons of strong high explosives in August 2009, and two explosions of about 10 and 100 tons of ANFO explosives in January 2011. It was a collaborative effort between Israel, CTBTO, USA and several European countries, with the main goal to provide fully controlled ground truth (GT0) infrasound sources, monitored by extensive observations, for calibration of International Monitoring System (IMS) infrasound stations in Europe, Middle East and Asia. In all shots, the explosives were assembled like a pyramid/hemisphere on dry desert alluvium, with a complicated explosion design, different from the ideal homogenous hemisphere used in similar experiments in the past. Strong boosters and an upward charge detonation scheme were applied to provide more energy radiated to the atmosphere. Under these conditions the evaluation of the actual explosion yield, an important source parameter, is crucial for the GT0 calibration experiment. Audio-visual, air-shock and acoustic records were utilized for interpretation of observed unique blast effects, and for determination of blast wave parameters suited for yield estimation and the associated relationships. High-pressure gauges were deployed at 100-600 m to record air-blast properties, evaluate the efficiency of the charge design and energy generation, and provide a reliable estimation of the charge yield. The yield estimators, based on empirical scaled relations for well-known basic air-blast parameters—the peak pressure, impulse and positive phase duration, as well as on the crater dimensions and seismic magnitudes, were analyzed. A novel empirical scaled relationship for the little-known secondary shock delay was developed, consistent for broad ranges of ANFO charges and distances, which facilitates using this stable and reliable air-blast parameter as a new potential

  1. Toxicology of explosives and fireworks in small animals. (United States)

    Gahagan, Patti; Wismer, Tina


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

  2. Sourcing explosives: a multi-isotope approach. (United States)

    Widory, David; Minet, Jean-Jacques; Barbe-Leborgne, Martine


    Although explosives are easily identified with current instrumental techniques, it is generally impossible to distinguish between sources of the same substance. To alleviate this difficulty, we present a multi-stable isotope (delta13C, delta15N, delta18O, deltaD) approach for appraising the possibility of discriminating explosives. The results from 30 distinct PETN, TNT and ANFO samples show that the different families of explosives are clearly differentiated by both their specific isotope signatures and their combination with corresponding element concentrations. Coupling two or more of the studied isotope systematics yields an even more precise differentiation on the basis of their raw-material origin and/or manufacturing process.

  3. Criticality safety in high explosives dissolution

    Energy Technology Data Exchange (ETDEWEB)

    Troyer, S.D.


    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.

  4. Magnetorotational Explosions of Core-Collapse Supernovae

    Directory of Open Access Journals (Sweden)

    Gennady S. Bisnovatyi-Kogan


    Full Text Available Core-collapse supernovae are accompanied by formation of neutron stars. The gravitation energy is transformed into the energy of the explosion, observed as SN II, SN Ib,c type supernovae. We present results of 2-D MHD simulations, where the source of energy is rotation, and magnetic eld serves as a "transition belt" for the transformation of the rotation energy into the energy of the explosion. The toroidal part of the magnetic energy initially grows linearly with time due to dierential rotation. When the twisted toroidal component strongly exceeds the poloidal eld, magneto-rotational instability develops, leading to a drastic acceleration in the growth of magnetic energy. Finally, a fast MHD shock is formed, producing a supernova explosion. Mildly collimated jet is produced for dipole-like type of the initial field. At very high initial magnetic field no MRI development was found.

  5. [First aid to persons with explosion trauma]. (United States)

    Shapovalov, V M; Samokhvalov, I M


    Modern organization providing medical aid to victims of explosion trauma in peace time, the success of which largely depends on the timely and professional interaction among the structures involeved into emergency relief operation is represented in the article. Content and sequence of events providing emergency medical and first medical aid to victims of the explosions, and the appropriateness of allocation affected groups, based on the predicted effectiveness of medical care is analyzed. The algorithm, currently used by ambulance crews, of assistance to victims with explosion and order evacuations is analyzed. The content of therapeutic measures in receipt of the wounded on the steps of skilled and specialized surgical care in accordance with the idea of a separation surgery on three stages (damage control). The content of the main levels of damage control orthopedics is introduced.

  6. PINS Testing and Modification for Explosive Identification

    Energy Technology Data Exchange (ETDEWEB)

    E.H. Seabury; A.J. Caffrey


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

  7. Securing Infrastructure from High Explosive Threats

    Energy Technology Data Exchange (ETDEWEB)

    Glascoe, L; Noble, C; Reynolds, J; Kuhl, A; Morris, J


    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.

  8. Explosive fragmentation of liquids in spherical geometry (United States)

    Milne, A.; Longbottom, A.; Frost, D. L.; Loiseau, J.; Goroshin, S.; Petel, O.


    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. Venting of gas explosion through relief ducts: interaction between internal and external explosions. (United States)

    Ferrara, G; Willacy, S K; Phylaktou, H N; Andrews, G E; Di Benedetto, A; Salzano, E; Russo, G


    Relief ducts fitted to venting openings is a widespread configuration in the industrial practice. The presence of a duct has been reported to severely increase the violence of the vented explosion posing a problem for the proper design of the venting device. Several studies have reported the leading importance--in the whole complex explosion phenomenology--of a secondary explosion in the duct. Modern approaches in the study of simply vented explosions (without ducts) have focused on the study of the interaction between internal and external explosion as a key issue in the mechanisms of pressure generation. The issue is even more relevant when a duct is fitted to the vent due the confined nature of the external explosion. In this work the interaction between internal and external events is experimentally investigated for gas explosions vented through a relief duct. The work has aimed at studying mechanisms underlying the pressure rise of this venting configuration. The study has put the emphasis on the mutual nature of the interaction. A larger scale than laboratory has been investigated allowing drawing results with a greater degree of generality with respect to data so far presented in literature.

  10. Potential explosion hazard of carbonaceous nanoparticles: Explosion parameters of selected materials. (United States)

    Turkevich, Leonid A; Dastidar, Ashok G; Hachmeister, Zachary; Lim, Michael


    Following a previous explosion screening study, we have conducted concentration and ignition energy scans on several carbonaceous nanopowders: fullerene, SWCNT, carbon black, MWCNT, graphene, CNF, and graphite. We have measured minimum explosive concentration (MEC), minimum ignition energy (MIE), and minimum ignition temperature (MITcloud) for these materials. The nanocarbons exhibit MEC ~10(1)-10(2) g/m(3), comparable to the MEC for coals and for fine particle carbon blacks and graphites. The nanocarbons are confirmed mainly to be in the St-1 explosion class, with fullerene, at K(St) ~200 bar-m/s, borderline St-1/St-2. We estimate MIE ~ 10(2)-10(3) J, an order of magnitude higher than the MIE for coals but an order of magnitude lower than the MIE for fine particle graphites. While the explosion severity of the nanocarbons is comparable to that of the coals, their explosion susceptibility (ease of ignition) is significantly less (i.e., the nanocarbons have higher MIEs than do the coals); by contrast, the nanocarbons exhibit similar explosion severity to the graphites but enhanced explosion susceptibility (i.e., the nanocarbons have lower MIEs than do the graphites). MIT(cloud) > 550 °C, comparable to that of the coals and carbon blacks. Published by Elsevier B.V.

  11. Ion Mobility Spectrometry - High Resolution LTQ-Orbitrap Mass Spectrometry for Analysis of Homemade Explosives (United States)

    Hagan, Nathan; Goldberg, Ilana; Graichen, Adam; St. Jean, Amanda; Wu, Ching; Lawrence, David; Demirev, Plamen


    The detailed chemical characterization of homemade explosives (HMEs) and other chemicals that can mimic or mask the presence of explosives is important for understanding and improving the performance of commercial instrumentation used for explosive detection. To that end, an atmospheric-pressure drift tube ion mobility spectrometry (IMS) instrument has been successfully coupled to a commercial tandem mass spectrometry (MS) system. The tandem MS system is comprised of a linear ion trap and a high resolution Orbitrap analyzer. This IMS-MS combination allows extensive characterization of threat chemical compounds, including HMEs, and complex real-world background chemicals that can interfere with detection. Here, the composition of ion species originating from a specific HME, erythritol tetranitrate, has been elucidated using accurate mass measurements, isotopic ratios, and tandem MS. Gated IMS-MS and high-resolution MS have been used to identify minor impurities that can be indicative of the HME source and/or synthesis route. Comparison between data obtained on the IMS/MS system and on commercial stand-alone IMS instruments used as explosive trace detectors (ETDs) has also been performed. Such analysis allows better signature assignments of threat compounds, modified detection algorithms, and improved overall ETD performance.

  12. Bioslurry treatment of explosives contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Zappi, M.; Gunnison, D.; Pennington, J.; Teeter, C. [USAE Waterways Experiment Station, Vicksburg, MS (United States). Environmental Lab.; Coyle, C.; Rope, C. [Army Engineer, Kansas City, MO (United States)


    Explosives contamination represents a widespread problem to the US Department of Defense (DOD) due to military activities associated with national defense. The US Army Engineer Waterways Experiment Station (WES) has evaluated the potential of several aerobic bioslurry process formulations for biotreatment of explosives compounds. This effort was conducted using five liter bench scale bioslurry reactors. Results were that the addition of a commercially available surfactant dramatically improved the treatment effectiveness of aerobic bioslurry. The surfactant amended bioreactors achieved an approximate 100 percent decrease in TNT half-life.

  13. Explosive opening switch work at Westinghouse (United States)

    Aivaliotis, E.; Peterhans, M.


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

  14. Explosive Outflows from Forming Massive Stars


    Bally, J.; Ginsburg, A.; Kasliwal, M. M.


    AO imaging of the near IR [Fe ii] and H_2 lines and ALMA CO J = 2 − 1 data confirms the explosive nature of the BN/KL outflow in Orion. N-body interactions in compact groups may be responsible for the production of powerful, explosive protostellar outflows and luminous infrared flares. The Orion event may have been triggered by a protostellar merger. First results of a search for Orion-like events in 200 nearby galaxies with the SPitzer InfraRed Intensive Transients Survey (SPIRITS) are brief...

  15. Spherical Solutions of an Underwater Explosion Bubble

    Directory of Open Access Journals (Sweden)

    Andrew B. Wardlaw


    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.

  16. Nanopowder synthesis based on electric explosion technology (United States)

    Kryzhevich, D. S.; Zolnikov, K. P.; Korchuganov, A. V.; Psakhie, S. G.


    A computer simulation of the bicomponent nanoparticle formation during the electric explosion of copper and nickel wires was carried out. The calculations were performed in the framework of the molecular dynamics method using many-body potentials of interatomic interaction. As a result of an electric explosion of dissimilar metal wires, bicomponent nanoparticles having different stoichiometry and a block structure can be formed. It is possible to control the process of destruction and the structure of the formed bicomponent nanoparticles by varying the distance between the wires and the loading parameters.

  17. Explosive detection using infrared laser spectroscopy (United States)

    Hildenbrand, J.; Herbst, J.; Wöllenstein, J.; Lambrecht, A.


    Stand-off and extractive explosive detection methods for short distances are investigated using mid-infrared laser spectroscopy. A quantum cascade laser (QCL) system for TATP-detection by open path absorption spectroscopy in the gas phase was developed. In laboratory measurements a detection limit of 5 ppm*m was achieved. For explosives with lower vapor pressure an extractive hollow fiber based measurement system was investigated. By thermal desorption gaseous TATP or TNT is introduced into a heated fiber. The small sample volume and a fast gas exchange rate enable fast detection. TNT and TATP detection levels below 100 ng are feasible even in samples with a realistic contaminant background.



    Turuchko, Ivan Ivanovych; Korshun, M.M.; Hubar, Inna Volodymyrivna


    The sanitary and hygienic characteristics of industrial explosives and their components are considered, the types of combinations of harmful substances in the air of the working zone at different technological stages of manufacturing explosives

  19. Modeling the Infrasound Acoustic Signal Generation of Underground Explosions at the Source Physics Experiment (United States)

    Whitaker, R. W.; Jones, K. R.; Arrowsmith, S.


    One of the primary goals of the Source Physics Experiment is to improve upon and develop new physics based models for underground nuclear explosions using scaled, underground chemical explosions as proxies. Jones et. al, (AGU 2012) previously presented results describing the use of the Rayleigh integral (RI) to model the source region of the SPE explosions. While these results showed that the source region could be modeled using the RI, there were some complexities in the produced, synthetic waveforms that were unaccounted for when compared to the observed data. To gain insight into these complexities and to verify the results of the RI method, we used CAVEAT, a two-dimensional computational fluid dynamics, time-domain finite-difference code developed at Los Alamos National Labs (LANL). CAVEAT has been used in the solution of high speed and low speed fluid problems. While the RI uses the observed acceleration records from the 12 vertical surface accelerometers installed above ground zero, CAVEAT employs a synthetic source-time function, based on the acceleration records, that varies with range and time. This model provides a velocity boundary condition at the bottom boundary of the CAVEAT computation mesh that drives the atmospheric pressure wave into the atmosphere.

  20. Explosive Eruptions of Kamchatkan Volcanoes in 2013 and Danger to Aviation (United States)

    Girina, Olga; Manevich, Alexander; Melnikov, Dmitry; Demyanchuk, Yury; Petrova, Elena


    There are 30 active volcanoes in the Kamchatka, and three of them (Sheveluch, Klyuchevskoy, and Karymsky) continuously active. In 2013, five of the Kamchatkan volcanoes - Sheveluch, Klyuchevskoy, Karymsky, Zhupanovsky, and Mutnovsky - had strong and moderate explosive eruptions. Strong explosive eruption of volcanoes is the most dangerous for aircraft because in a few hours or days in the atmosphere and the stratosphere can produce about several cubic kilometers of volcanic ash and aerosols. Ash plumes and the clouds, depending on the power of the eruption, the strength and wind speed, can travel thousands of kilometers from the volcano for several days, remaining hazardous to aircraft, as the melting temperature of small particles of ash below the operating temperature of jet engines. The eruptive activity of Sheveluch Volcano began since 1980 (growth of the lava dome) and is continuing at present. Strong explosive events of the volcano occurred in 2013: on June 26, on October 18, and on December 03: ash plumes rose up to 10 km a.s.l. and extended about 200-400 km, respectively, to the south-west, south-southeast, and north of the volcano. A form of pyroclastic flow deposits with run-out 12 km accompanied these explosive eruptions. Ashfalls occurred at Klyuchi Village (on June 26) and Ivashka Village (on December 03). Activity of the volcano was dangerous to international and local aviation. Klyuchevskoy volcano had two eruptions in 2013: moderate Strombolian explosive eruption from October 14, 2012, till January 15, 2013; and strong Strombolian-Vulcanian explosive and effusive eruption from August 15, 2013, till December 20, 2013. There were four lava flows to effuse on the north-west, west and south-western volcanic flanks. Probably a flank eruption began at the pass between Klyuchevskoy volcano and Kamen volcano on October 06. Culmination of strong Vulcanian explosive activity of the volcano occurred on October 15-20: ash column rose up to 10-12 km a.s.l. and

  1. Evaluation of the Thermochemical Code - CHEETAH 2.0 for Modelling Explosives Performance

    National Research Council Canada - National Science Library

    Lu, Jing


    The Lawrence Livermore National Laboratory CHEETAH 2.0 program has been used to analyse a number of conventional ideal explosive ingredients, ideal explosive compositions, non-ideal explosive compositions, and new and proposed explosives...

  2. Contamination mechanisms of air basin with tritium in venues of underground nuclear explosions at the former Semipalatinsk test site. (United States)

    Lyakhova, O N; Lukashenko, S N; Larionova, N V; Tur, Y S


    During the period of testing from 1945 to 1962 at the territory of Semipalatinsk test site (STS) within the Degelen Mountains in tunnels, 209 underground nuclear explosions were produced. Many of the tunnels have seasonal water seepage in the form of streams, through which tritium migrates from the underground nuclear explosion (UNE) venues towards the surface. The issue of tritium contamination occupies a special place in the radioactive contamination of the environment. In this paper we assess the level and distribution of tritium in the atmospheric air of ecosystems with water seepage at tunnels № 176 and № 177, located on "Degelen" site. There has been presented general nature of tritium distribution in the atmosphere relative to surface of a watercourse which has been contaminated with tritium. The basic mechanisms were studied for tritium distribution in the air of studied ecosystems, namely, the distribution of tritium in the systems: water-atmosphere, tunnel air-atmosphere, soil water-atmosphere, vegetation-atmosphere. An analytical calculation of tritium concentration in the atmosphere by the concentration of tritium in water has been performed. There has experimentally obtained the dependence for predictive assessment of tritium concentrations in air as a function of tritium concentration in one of the inlet sources such as water, tunnel air, soil water, vegetation, etc.. The paper also describes the general nature of tritium distribution in the air in the area "Degelen". Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Landmine Detection Technologies to TraceExplosive Vapour Detection Techniques


    J. C. Kapoor; G. K. Kannan


    Large quantity of explosive is manufactured worldwide for use in various types of ammunition,arms, and mines, and used in armed conflicts. During manufacturing and usage of the explosiveequipment, some of the explosive residues are released into the environment in the form ofcontaminated effluents, unburnt explosives fumes and vapours. Limited but uncontrolledcontinuous release of trace vapours also takes place when explosive-laden landmines are deployedin the field. One of the major technolo...

  4. A Study of the behaviour of emulsion explosives


    Allum, J


    This study investigated the formulation and characterisation of emulsion explosives. This included the manufacture of more than 120kg of emulsion explosive of which around 105kg was used on the explosive ordnance range in over 350 individual firings. For each emulsion composition, an average of eight firings was undertaken with which to substantiate the explosive performance data. The formulation was varied to determine the effects of water content upon the physical characte...

  5. Source analysis of underground chemical explosions (United States)

    Chiang, A.; Ford, S. R.; Pitarka, A.


    Several physical mechanisms have been proposed to explain the generation of S-waves from underground explosions, such as asymmetries in the source, release of tectonic pre-stress, interactions with the free-surface, and heterogeneities in the Earth. An accurate description of the explosion source processes is an important step towards understanding which of these plausible mechanisms are actively contributing to the generation of S-waves and under what conditions. In this study we investigate the sensitivity of far-field waveforms to seismic source mechanisms by comparing simulated and recorded data from underground chemical explosions performed during the Source Physics Experiment. We use both forward and inverse waveform modeling approaches to estimate the source properties of the explosions, and compare solutions using different velocity models and at different frequency bands and distances. 1D and 3D velocity models are used to characterize wave propagation between the source and receiver. The 3D velocity models are constructed using available geological and geophysical data, and ambient noise seismic tomography. The 3D Green's functions are computed using a numerical finite-difference approach. We will investigate the sensitivity of far-field ground motion to different levels of source complexities, such as a single isotropic source or complex sources with non-isotropic radiation in the frequency range of 0.5 to 6 Hz.

  6. 78 FR 1143 - Explosive Siting Requirements; Correction (United States)


    ... increases flexibility for launch site operators in site planning for the storage and handling of energetic... this final rule, contact Laura Montgomery, AGC 200, ] Senior Attorney for Commercial Space... in site planning for the storage and handling of energetic liquids and explosives. In the discussion...

  7. DOD Ammunition and Explosives Safety Standards (United States)


    following: bulk lead azide, lead styphnate, mercury fulminate , tetracene, dry cyclotrimethylenetrinitramine (RDX) (also known as cyclonite, hexogen, or...primary explosives are lead azide and mercury fulminate . AP1.191. Primary fragment. A fragment from material in intimate contact with reacting AE

  8. Wave forming mechanisms in explosive welding

    NARCIS (Netherlands)

    Carton, E.P.


    Experimental results of wavy metal interfaces obtained by explosive welding are presented and used to determine which wave forming mechanism occurred. It was found that for small collision angles (smaller than about 20°) the Von Karman or jet indentation mechanism occurs, while for large collision

  9. Explosives safety research in the Netherlands

    NARCIS (Netherlands)

    Voort, M.M. van der; Weerheijm, J.; Wees, R.M.M. van; Dongen. P. van


    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

  10. EUExNet - A European Explosives Network (United States)


    Tallinn Technical University (EE) • University of Latvia (LV) • Sprengschule Dresden (DE) • LEDAP (PT) • Irish Industrial Explosives (IR) • EFEE (EU...Univ. Latvia WP2 DISSEMINATION Chair KCEM WP3 QC and QA Chair KAU WP4 National nodes Chair IExpE WP5 Certification Chair LEDAP WP6 European

  11. Java: An Explosion on the Internet. (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…

  12. Differential thermal analysis microsystem for explosive detection

    DEFF Research Database (Denmark)

    Olsen, Jesper Kenneth; Greve, Anders; Senesac, L.


    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 a...... of the Xsense project at the Technical University of Denmark (DTU) which combines four independent sensing techniques, these micro DNT sensors will be included in handheld explosives detectors with applications in homeland security and landmine clearance.......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...... as a small silicon nitride membrane incorporating heater elements and a temperature measurement resistor. In this manuscript the DTA system is described and tested by measuring calorimetric response of 3 different kinds of explosives (TNT, RDX and PETN). This project is carried out under the framework...

  13. 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.


    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

  14. Explosion proof vehicle for tank inspection (United States)

    Zollinger, William T [Idaho Falls, ID; Klingler, Kerry M [Idaho Falls, ID; Bauer, Scott G [Idaho Falls, ID


    An Explosion Proof Vehicle (EPV) having an interior substantially filled with an inert fluid creating an interior pressure greater than the exterior pressure. One or more flexible tubes provide the inert fluid and one or more electrical conductors from a control system to the vehicle. The vehicle is preferably used in subsurface tank inspection, whereby the vehicle is submerged in a volatile fluid.

  15. The Physics, Chemistry and Dynamics of Explosions (United States)


    is to follow. 2. Fundamentals The basis of our present understanding began with the experimental observations of Berthelot & Vieille [1] and Mallard...carried out. References 1 Berthelot , M. & Vieille, P. 1881 On the propagation velocity of explosion phenomena. Acad. Sci. Comptes Rendus Math. 93, 18–22. 2

  16. Construction of hydrogenation stalls for explosions

    Energy Technology Data Exchange (ETDEWEB)

    Raichle, L.


    This report contained explanations for different questions that had been asked by the Association of Chemical Manufacturers. The first item discussed was the pressure occurring in hydrogenation stalls in hydrogen explosions. The pressures actually used were much smaller than the maximum design pressure due to burning gases being allowed to escape from the top and front of the stalls since these areas were open and it could not be assumed that the whole stall space was filled with a 32% hydrogen concentration at the beginning of an explosion. The second item discussed was specifications and rules for the building of hydrogenation stalls. These included the calculations for simple wind pressure according to the Building Code with the usual safety factors and the calculations for an inner pressure of 300 kg/m/sup 2/ with the usual safety factors. An explanation of a stall explosion in Poelitz and reinforced stall construction in Poelitz were two other items that were discussed. Appendix I of the report involved maximum pressures and temperature in hydrogen explosions. Diagram I was involved with this. Appendix II discussed the behavior of a hydrogen flame at high emerging velocities and Appendix III discussed stall construction at Poelitz.

  17. 75 FR 1085 - Commerce in Explosives; List of Explosive Materials (2009R-18T) (United States)


    ... mixtures. Explosive powders. F Flash powder. Fulminate of mercury. Fulminate of silver. Fulminating gold. Fulminating mercury. Fulminating platinum. Fulminating silver. G Gelatinized nitrocellulose. Gem-dinitro...-dinitropentanoate]. MEAN [monoethanolamine nitrate]. Mercuric fulminate. Mercury oxalate. Mercury tartrate. Metriol...

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


    ... Flash powder. Fulminate of mercury. Fulminate of silver. Fulminating gold. Fulminating mercury. Fulminating platinum. Fulminating silver. G Gelatinized nitrocellulose. Gem-dinitro aliphatic explosive.... MDNP . MEAN . Mercuric fulminate. Mercury oxalate. Mercury tartrate. Metriol trinitrate. Minol-2 . MMAN...

  19. Determination of explosive blast loading equivalencies with an explosively driven shock tube

    Energy Technology Data Exchange (ETDEWEB)

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


    Recently there has been significant interest in evaluating the potential of many different non-ideal energetic materials to cause blast damage. We present a method intended to quantitatively compare the blast loading generated by different energetic materials through use of an explosively driven shock tube. The test explosive is placed at the closed breech end of the tube and initiated with a booster charge. The resulting shock waves are then contained and focused by the tube walls to form a quasi-one-dimensional blast wave. Pressure transducers along the tube wall measure the blast overpressure versus distance from the source and allow the use of the one-dimensional blast scaling relationship to determine the energy deposited into the blast wave per unit mass of test explosive. These values are then compared for different explosives of interest and to other methods of equivalency determination.

  20. Expediency of application of explosion-relief constructions to ensure explosion resistance of production buildings

    Directory of Open Access Journals (Sweden)

    Lyapin Anton


    Full Text Available The article presents a model of economic evaluation and selection of explosion-relief constructions (ERC, as well as determination of explosion protection efficiency of buildings and structures provided on a stage of construction. It has been shown that definition of economic efficiency of ERС is the evaluation of its application for buildings with remote or automatically controlled production. It has been determined that an important role in design of explosive industrial facilities is played by selection of the economically feasible and effective materials for ERC. When selecting materials it is necessary to consider probability and yield of explosions. Necessity to create the methods allow considering such probability has been revealed.

  1. Modeling cookoff of HMX based PBX explosives

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, Michael L.


    We have previously developed a PBX 9501 cookoff model for the plastic bonded explosive PBX 9501 consisting of 95 wt% octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazoncine (HMX), 2.5 wt% Estane® 5703 (a polyurethane thermoplastic), and 2.5 wt% of a nitroplasticizer (NP): BDNPA/F, a 50/50 wt% eutectic mixture bis(2,2-dinitropropyl)-acetal (BDNPA) and bis(2,2-dinitropropyl)-formal (BDNPF). This fivestep model includes desorption of water, decomposition of the NP to form NO2, reaction of the NO2 with Estane and HMX, and decomposition of HMX [1]. This model has been successfully validated with data from six laboratories with scales ranging from 2 g to more than 2.5 kg of explosive. We have determined, that the PBX 9501 model can be used to predict cookoff of other plastic bonded explosives containing HMX and an inert binder, such as LX-04 consisting of 85 wt% HMX and 15 wt% Viton A (vinylidine fluoride/hexafluoropropylene copolymer), LX-07 (90 wt% HMX and 10 wt% Viton A), LX- 10-0 (95 wt% HMX and 5 wt% Viton A), and LX-14 consisting of 95.5 wt % HMX and 4.5 wt% Estane® 5702-F1 (a polyurethane thermoplastic). Normally our cookoff models are verified using Sandia’s Instrumented Thermal Initiation (SITI) experiment. However, SITI data for LX-04, LX-07, LX-10-0, and LX-14 are not available at pressed density; although, some molding powder SITI data on LX-10-0 and LX-14 exists. Tarver and Tran [2] provide some one-dimensional time-to-explosion (ODTX) data for these explosives. The applicability of the PBX 9501 model to LX-04, LX-07, LX-10-0, AND LX-14 was made using this ODTX data [2]. The PBX 9501 model is applied to these other explosives by accounting for the correct amount of HMX in the explosive and limiting the NP reaction. We have found the PBX 9501 model to be useful for predicting the response of these PBXs to abnormal thermal environments such as fire.

  2. Micro-explosion of compound drops (United States)

    Chen, Chun-Kuei; Lin, Ta-Hui


    Introducing water into spray combustion systems, by either water-in-oil emulsification or supplementary water injection, is one of the major techniques for combustion improvement and NOx reduction. Plentiful researches are available on combustion of water-in-oil emulsion fuel drops. The emulsified liquid is a heterogeneous mixture of immiscible liquids. One component forms the continuous phase and the other component forms the discrete phase. The discrete phase consists of globules of the one fluid that are suspended in the continuous phase fluid. Water-in-oil emulsions are commonly considered for combustion applications because emulsions can result in micro-explosion, thereby reducing the average drop diameter to enhance liquid vaporization, and suppressing the formation of soot and NOx. However, the water addition generally does not exceed about 20% for smooth engine operations[!, 21. The combustion characteristics and micro-explosion of emulsion drop were studied by many researchers. The micro-explosion of water in fuel emulsion drops was caused by very fast growth of superheated water vapor bubbles, its superheat limits must be lower than the boiling point temperature of the fuel. These bubbles were primarily governed by the pressure difference between the superheated vapor and the liquid, and by the inertia imparted to the liquid by the motion of the bubble surface[3 6 In this study, we used a coaxial nozzle to generation the multi-component drop. The different type of water-in-oil fuel drops called the compound drops. Unlike an emulsion drop, a compound drop consists of a water core and a fuel shell, which can originate from the phase separation of emulsion[7, 81 or a water drop colliding with a fuel drop[9, 101 Burning and micro-explosion of compound drops have been found to be distinct from those of emulsion drops[9-111 Wang et al.[9 , 101 studied the combustion characteristics of collision merged alkane-water drops. The merged drops appeared in adhesive

  3. Increase of water resistance of ammonium nitrate explosives

    Directory of Open Access Journals (Sweden)

    Zulkhair Mansurov


    Full Text Available Developed a method of kapsulating of ammonium nitrate with liquid paraffin increase finding explosives in water for 60 minutes. Placing explosives in the plastic shell, the explosive was, as in standing or running water during the day. When conducting field tests failures were absent.

  4. an experimental investigation into the explosive forming of square ...

    African Journals Online (AJOL)

    ES Obe


    Mar 1, 1981 ... The explosive forming of steel blanks into a perforated square die of side 200 mm and depth 40 mm has been investigated. ... quantity of explosive needed for successful forming. The results also show that the indentation of ..... the Use of. Vented Dies in Explosive Forming of. Metal Sheets" ,Presented at the.

  5. Recent Advances in the Synthesis of High Explosive Materials

    Directory of Open Access Journals (Sweden)

    Jesse J. Sabatini


    Full Text Available This review discusses the recent advances in the syntheses of high explosive energetic materials. Syntheses of some relevant modern primary explosives and secondary high explosives, and the sensitivities and properties of these molecules are provided. In addition to the synthesis of such materials, processing improvement and formulating aspects using these ingredients, where applicable, are discussed in detail.

  6. 49 CFR 173.57 - Acceptance criteria for new explosives. (United States)


    ... appendix D to this part), a non-gelatin dynamite loses more than 3 percent by weight of the liquid explosive or a gelatin dynamite loses more than 10 percent by weight of the liquid explosive; or (3) During... 49 Transportation 2 2010-10-01 2010-10-01 false Acceptance criteria for new explosives. 173.57...

  7. 30 CFR 19.7 - Protection against explosion hazard. (United States)


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Protection against explosion hazard. 19.7..., EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC CAP LAMPS § 19.7 Protection against explosion hazard. Unless properly designed, electric cap lamps may present two sources of probable explosion hazards...

  8. A model to assess dust explosion occurrence probability. (United States)

    Hassan, Junaid; Khan, Faisal; Amyotte, Paul; Ferdous, Refaul


    Dust handling poses a potential explosion hazard in many industrial facilities. The consequences of a dust explosion are often severe and similar to a gas explosion; however, its occurrence is conditional to the presence of five elements: combustible dust, ignition source, oxidant, mixing and confinement. Dust explosion researchers have conducted experiments to study the characteristics of these elements and generate data on explosibility. These experiments are often costly but the generated data has a significant scope in estimating the probability of a dust explosion occurrence. This paper attempts to use existing information (experimental data) to develop a predictive model to assess the probability of a dust explosion occurrence in a given environment. The pro-posed model considers six key parameters of a dust explosion: dust particle diameter (PD), minimum ignition energy (MIE), minimum explosible concentration (MEC), minimum ignition temperature (MIT), limiting oxygen concentration (LOC) and explosion pressure (Pmax). A conditional probabilistic approach has been developed and embedded in the proposed model to generate a nomograph for assessing dust explosion occurrence. The generated nomograph provides a quick assessment technique to map the occurrence probability of a dust explosion for a given environment defined with the six parameters. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Forensic analysis of explosions: Inverse calculation of the charge mass

    NARCIS (Netherlands)

    Voort, M.M. van der; Wees, R.M.M. van; Brouwer, S.D.; Jagt-Deutekom, M.J. van der; Verreault, J.


    Forensic analysis of explosions consists of determining the point of origin, the explosive substance involved, and the charge mass. Within the EU fP7 project Hyperion, TNO developed the Inverse Explosion Analysis (TNO-IEA) tool to estïmate the charge mass and point of origin based on observed damage

  10. 30 CFR 75.1311 - Transporting explosives and detonators. (United States)


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Transporting explosives and detonators. 75.1311... Transporting explosives and detonators. (a) When explosives and detonators are to be transported underground... transported by any cars or vehicles— (1) The cars or vehicles shall be marked with warnings to identify the...

  11. 27 CFR 555.63 - Explosives magazine changes. (United States)


    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Explosives magazine... § 555.63 Explosives magazine changes. (a) General. (1) The requirements of this section are applicable to magazines used for other than temporary (under 24 hours) storage of explosives. (2) A magazine is...

  12. Increase of water resistance of ammonium nitrate explosives


    Zulkhair Mansurov; Y. Kazakov; Roza Abdulkarimova; A. Kosmaganbetova


    Developed a method of kapsulating of ammonium nitrate with liquid paraffin increase finding explosives in water for 60 minutes. Placing explosives in the plastic shell, the explosive was, as in standing or running water during the day. When conducting field tests failures were absent.

  13. Fluid Interactions with Explosion-Induced Fractures (United States)

    Swanson, E.; Sussman, A. J.; Wilson, J.; Broome, S.


    Fluids can chemically interact with the fractures they flow through, a process that may affect the movement of fluids in the subsurface. This is a topic of interest to a large variety of research areas, including (but not limited to) production of oil and gas, contaminant tracking, geothermal energy production, CO2 sequestration, and nuclear test monitoring. A study performed as part of the Source Physics Experiment, designed to look at the effects of underground chemical explosions, provides a rare opportunity to compare cores from pre-shot and post-shot rock, from damage created in situ. We present data on the variability of microfracture density with distance from the explosion, as well as the occurrence of fractures that either open or contain clay infill. We find that both open and filled fractures occur more frequently within the post-shot samples (by a factor of up to 4x), with similar spatial distributions. This calls into question the validity of the commonly made assumption that all filled fractures were present prior to the explosive shot, and only open fractures can represent explosion-induced damage. These results suggest that fluid-rock interactions might have a significant influence on the permeabilities that result from explosions, even within a few weeks. Additional data on the mechanical properties of the pre-shot and post-shot core samples show an unexpected pattern during unconfined compressive strength tests: the samples retrieved following 2 successive shots failed at higher stresses than did samples retrieved after 1 shot. We present these results, along with some evidence this behavior may arise from trace differences in water content during testing.

  14. Plutonium explosive dispersal modeling using the MACCS2 computer code

    Energy Technology Data Exchange (ETDEWEB)

    Steele, C.M.; Wald, T.L.; Chanin, D.I.


    The purpose of this paper is to derive the necessary parameters to be used to establish a defensible methodology to perform explosive dispersal modeling of respirable plutonium using Gaussian methods. A particular code, MACCS2, has been chosen for this modeling effort due to its application of sophisticated meteorological statistical sampling in accordance with the philosophy of Nuclear Regulatory Commission (NRC) Regulatory Guide 1.145, ``Atmospheric Dispersion Models for Potential Accident Consequence Assessments at Nuclear Power Plants``. A second advantage supporting the selection of the MACCS2 code for modeling purposes is that meteorological data sets are readily available at most Department of Energy (DOE) and NRC sites. This particular MACCS2 modeling effort focuses on the calculation of respirable doses and not ground deposition. Once the necessary parameters for the MACCS2 modeling are developed and presented, the model is benchmarked against empirical test data from the Double Tracks shot of project Roller Coaster (Shreve 1965) and applied to a hypothetical plutonium explosive dispersal scenario. Further modeling with the MACCS2 code is performed to determine a defensible method of treating the effects of building structure interaction on the respirable fraction distribution as a function of height. These results are related to the Clean Slate 2 and Clean Slate 3 bunkered shots of Project Roller Coaster. Lastly a method is presented to determine the peak 99.5% sector doses on an irregular site boundary in the manner specified in NRC Regulatory Guide 1.145 (1983). Parametric analyses are performed on the major analytic assumptions in the MACCS2 model to define the potential errors that are possible in using this methodology.

  15. Action Replay of Powerful Stellar Explosion (United States)


    Astronomers have made the best ever determination of the power of a supernova explosion that was visible from Earth long ago. By observing the remnant of a supernova and a light echo from the initial outburst, they have established the validity of a powerful new method for studying supernovas. Using data from NASA's Chandra X-ray Observatory, ESA's XMM-Newton Observatory, and the Gemini Observatory, two teams of researchers studied the supernova remnant and the supernova light echo that are located in the Large Magellanic Cloud (LMC), a small galaxy about 160,000 light years from Earth. They concluded that the supernova occurred about 400 years ago (in Earth’s time frame), and was unusually bright and energetic. X-ray Image of SNR 0509-67.5 X-ray Image of SNR 0509-67.5 This result is the first time two methods - X-ray observations of a supernova remnant and optical observations of the expanding light echoes from the explosion - have both been used to estimate the energy of a supernova explosion. Up until now, scientists had only made such an estimate using the light seen soon after a star exploded, or using remnants that are several hundred years old, but not from both. "People didn't have advanced telescopes to study supernovas when they went off hundreds of years ago," said Armin Rest of Harvard University, who led the light echo observations using Gemini. "But we've done the next best thing by looking around the site of the explosion and constructing an action replay of it." People Who Read This Also Read... Milky Way's Super-efficient Particle Accelerators Caught in The Act Oldest Known Objects Are Surprisingly Immature Discovery of Most Recent Supernova in Our Galaxy NASA Unveils Cosmic Images Book in Braille for Blind Readers In 2004, scientists used Chandra to determine that a supernova remnant, known as SNR 0509-67.5 in the LMC, was a so-called Type Ia supernova, caused by a white dwarf star in a binary system that reaches a critical mass and explodes. In

  16. Modeling of atmospheric-coupled Rayleigh waves on planets with atmosphere: From Earth observation to Mars and Venus perspectives. (United States)

    Lognonné, Philippe; Karakostas, Foivos; Rolland, Lucie; Nishikawa, Yasuhiro


    Acoustic coupling between solid Earth and atmosphere has been observed since the 1960s, first from ground-based seismic, pressure, and ionospheric sensors and since 20 years with various satellite measurements, including with global positioning system (GPS) satellites. This coupling leads to the excitation of the Rayleigh surface waves by local atmospheric sources such as large natural explosions from volcanoes, meteor atmospheric air-bursts, or artificial explosions. It contributes also in the continuous excitation of Rayleigh waves and associated normal modes by atmospheric winds and pressure fluctuations. The same coupling allows the observation of Rayleigh waves in the thermosphere most of the time through ionospheric monitoring with Doppler sounders or GPS. The authors review briefly in this paper observations made on Earth and describe the general frame of the theory enabling the computation of Rayleigh waves for models of telluric planets with atmosphere. The authors then focus on Mars and Venus and give in both cases the atmospheric properties of the Rayleigh normal modes and associated surface waves compared to Earth. The authors then conclude on the observation perspectives especially for Rayleigh waves excited by atmospheric sources on Mars and for remote ionospheric observations of Rayleigh waves excited by quakes on Venus.

  17. Forensic analyses of explosion debris from the January 2, 1992 Pd/D{sub 2}O electrochemistry incident at SRI International

    Energy Technology Data Exchange (ETDEWEB)

    Andresen, B.; Whipple, R.; Vandervoort, D.; Grant, P.


    The January 2, 1992 explosion in an electrochemistry laboratory at SRI International (SRI) resulted in the death of scientist Andrew Riley, and gained some notoriety due to its association with experimental work in the controversial field of cold fusion research. Selected components of explosion debris were subjected to forensic analyses at LLNL to elucidate potential causes of, or contributing factors to, the explosion. Interrogation of the debris by LLNL encompassed nuclear, chemical, physical, and materials investigations. Nuclear studies for the determination of tritium and neutron-activation products in stainless steel and brass were negative. No evidence of signature species indicative of orthodox nuclear events was detected. The inorganic and particulate analyses were likewise negative with respect to residues of unexpected chemical species. Such target compounds included conventional explosives, accelerants, propellants, or any exceptional industrial chemicals. The GC-MS analyses of trace organic components in the explosion debris provided perhaps the most interesting results obtained at LLNL. Although no evidence of organic explosives, oxidizers, or other unusual compounds was detected, the presence of a hydrocarbon oil in the interior of the electrochemical cell was established. It is likely that its source was lubricating fluid from the machining of the metal cell components. If residues of organic oils are present during electrolysis experiments, the potential exists for an explosive reaction in the increasingly enriched oxygen atmosphere within the headspace of a metal cell.

  18. Acoustic waves in the atmosphere and ground generated by volcanic activity

    Energy Technology Data Exchange (ETDEWEB)

    Ichihara, Mie; Lyons, John; Oikawa, Jun; Takeo, Minoru [Earthquake Research Institute, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan); Instituto Geofisico, Escuela Politecnica Nacional, Ladron de Guevara E11-253, Aptdo 2759, Quito (Ecuador); Earthquake Research Institute, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan)


    This paper reports an interesting sequence of harmonic tremor observed in the 2011 eruption of Shinmoe-dake volcano, southern Japan. The main eruptive activity started with ashcloud forming explosive eruptions, followed by lava effusion. Harmonic tremor was transmitted into the ground and observed as seismic waves at the last stage of the effusive eruption. The tremor observed at this stage had unclear and fluctuating harmonic modes. In the atmosphere, on the other hand, many impulsive acoustic waves indicating small surface explosions were observed. When the effusion stopped and the erupted lava began explosive degassing, harmonic tremor started to be transmitted also to the atmosphere and observed as acoustic waves. Then the harmonic modes became clearer and more stable. This sequence of harmonic tremor is interpreted as a process in which volcanic degassing generates an open connection between the volcanic conduit and the atmosphere. In order to test this hypothesis, a laboratory experiment was performed and the essential features were successfully reproduced.

  19. 27 CFR 555.180 - Prohibitions relating to unmarked plastic explosives. (United States)


    ...) Plastic explosive means an explosive material in flexible or elastic sheet form formulated with one or... unmarked plastic explosives. 555.180 Section 555.180 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES...

  20. Development in the Detection and Identification of Explosive Residues. (United States)

    Beveridge, A D


    In the past 2 decades, developments in the sensitivity and selectivity of instrument detectors have significantly improved the detection limits for explosives, particularly nitrated organic compounds. Significant improvements have also been made in clean up and recovery procedures for explosive residues. Methods which also have met the criterion of proven effectiveness in identifying explosive components in "real-world" residues from test explosions have been incorporated into systematic analysis protocols for explosive residues. This article first reviews developments in the application of both traditional and novel methods to analysis of unreacted explosives and explosive residues. Compounds used to formulate commercial, military, and "homemade" explosives are then cross-referenced to the analytical methods that have been specifically applied to them, both as pure chemicals and in explosive mixtures. The subsequent focus is on the combinations of methods used to systematically analyze and positively identify residues from improvised explosive devices, from handswabs derived from persons suspected of handling explosives, and from organic gunshot residue. Technology is available to positively identify virtually any unreacted explosive in residue, but no one method can detect all components of all explosives. Investigators and the courts are best served by well-equipped forensic science laboratories staffed with scientists who have gained experience by the successful analysis of post-blast residues from an explosives range and have comprehensive reference collections of physical material, analytical data, and literature. The greatest progress has been made with respect to nitrated organic compounds, but the new generation of commercial explosive slurries and emulsions which are primarily formulated with inorganic salts and non-nitrated organic compounds offer an ongoing challenge. Copyright © 1992 Central Police University.

  1. Analysis of the accidental explosion at Pepcon, Henderson, Nevada, May 4, 1988

    Energy Technology Data Exchange (ETDEWEB)

    Reed, J.W.


    Several hours of fire and numerous explosions destroyed the Pacific Engineering Company plant in Henderson, Nevada, that manufactured ammonium perchlorate (AP) for rocket fuel. This incident began about 1130 PDT on May 4, 1988, with a fire in their Batch House that grew out of control and caused a first large explosion at about 1153 PDT. The final and largest explosion occurred about 1157 PDT. Damages to the surrounding community were surveyed and interpreted as airblast overpressures versus distances, which allowed an estimate of 1-kiloton nuclear free-air-burst for the equivalent explosion yield. This could be reproduced by 250-tons TNT burst on the ground surface. Weather reports were obtained from the National Weather Services which indicated somewhat enhanced airblast propagation downwind toward northerly directions and attenuated airblast propagations upwind in southerly directions. It was impossible, for lack of winds aloft information below about 500 m above ground, to determine whether there was any atmospheric acoustic airblast focusing. Several seismic recordings in Las Vegas showed the greatest ground motion resulted from the airblast wave passage, traveling at near acoustic speed. Ground wave arrival times were not sufficiently precise to allow seismic speed interpretations. Of the 4000 tons of AP apparently stored in and around the plant, it appears that about 1500 tons detonated in the largest explosion. This leads to a conclusion that the TNT airblast equivalence factor for AP is near 1/6. An independent estimate, based on analysis of more ideal close-in structural deformations, suggested an equivalence factor of 1/3. 25 refs., 12 figs., 14 tabs.

  2. DOE TMD transportation training module 14 transportation of explosives

    Energy Technology Data Exchange (ETDEWEB)

    Griffith, R.L. Jr.


    The Department of Energy Transportation Management Division has developed training module 14, entitled {open_quotes}Transportation of Explosives{close_quotes} to compliment the basic {open_quotes}core ten{close_quotes} training modules of the Hazardous Materials Modular Training Program. The purpose of this training module is to increase awareness of the Department of Transportation (DOT) requirements concerning the packaging and transportation of explosives. Topics covered in module 14 include the classification of explosives, approval and registration of explosives, packaging requirements, hazard communication requirements, separation and segregation compatibility requirements, loading and unloading operations, as well as safety measures required in the event of a vehicle accident involving explosives.


    Directory of Open Access Journals (Sweden)

    Matej MENČÍK


    Full Text Available The aim of this paper is to approximate danger of dust clouds normally occur by determining their explosion characteristics. Nowadays, dusty environment is phenomenon in the industry. In general, about 70% of dust produced is explosive. Dust reduction in companies is the main purpose of the national and European legislative. Early identification and characterization of dust in companies may reduce the risk of explosion. It could be used to identify hazards in industrial production where an explosive dust is produced. For this purpose several standards for identification and characterization of explosion characteristics of industrial dust are being used.

  4. Explosive Eruptions of Kamchatkan Volcanoes in 2012 and Danger to Aviation (United States)

    Girina, Olga; Manevich, Alexander; Melnikov, Dmitry; Nuzhdaev, Anton; Demyanchuk, Yury; Petrova, Elena


    Strong explosive eruption of volcanoes is the most dangerous for aircraft because in a few hours or days in the atmosphere and the stratosphere can produce about several cubic kilometers of volcanic ash and aerosols. Ash plumes and the clouds, depending on the power of the eruption, the strength and wind speed, can travel thousands of kilometers from the volcano for several days, remaining hazardous to aircraft, as the melting temperature of small particles of ash below the operating temperature of jet engines. There are 30 active volcanoes in the Kamchatka and 6 active volcanoes in the Northern Kuriles, and 4 of them continuously active. In 2012 seven strong explosive eruptions of the Kamchatkan and the Northern Kuriles volcanoes Sheveluch, Bezymianny, Kizimen, Tolbachik, Klyuchevskoy, and Karymsky took place. In addition, higher fumarolic activity of Gorely volcano was observed. The eruptive activity of Sheveluch Volcano began since 1980 (growth of the lava dome) and is continuing at present. Strong explosive events of the volcano occurred in 2012: on January 22-23; on March 16-17; March 25-30 - June 03; and on September 18: ash plumes rose up to 10 km a.s.l. and extended about 200-2000 km to the different directions of the volcano. The eruptive activity of Bezymianny volcano began since 1955, and is continuing at present as growth of the lava dome. Two paroxysmal explosive phases of the eruption occurred on March 08 and September 01: ash plumes rose up to 8-12 km a.s.l. and extended about 1500 km to the east-north-east of the volcano. Eruption of Kizimen volcano began on December 09, 2010, and continues. Strong explosive eruption began in mid-December, 2010, - ash plumes rose up to 10 km a.s.l. and extended > 800 km from the volcano. There are several stages of the eruption: explosive (from 09 December 2010 to mid-January 2011); explosive-effusive (mid-January to mid-June 2011); effusive (mid-January 2011 to September 2012). Extrusive-effusive phase of eruption

  5. Planar blast scaling with condensed-phase explosives in a shock tube

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, Scott L [Los Alamos National Laboratory


    Blast waves are strong shock waves that result from large power density deposition into a fluid. The rapid energy release of high-explosive (HE) detonation provides sufficiently high power density for blast wave generation. Often it is desirable to quantify the energy released by such an event and to determine that energy relative to other reference explosives to derive an explosive-equivalence value. In this study, we use condensed-phase explosives to drive a blast wave in a shock tube. The explosive material and quantity were varied to produce blast waves of differing strengths. Pressure transducers at varying lengths measured the post-shock pressure, shock-wave arrival time and sidewall impulse associated with each test. Blast-scaling concepts in a one-dimensional geometry were then used to both determine the energy release associated with each test and to verify the scaling of the shock position versus time, overpressure versus distance, and impulse. Most blast scaling measurements to-date have been performed in a three-dimensional geometry such as a blast arena. Testing in a three-dimensional geometry can be challenging, however, as spherical shock-wave symmetry is required for good measurements. Additionally, the spherical wave strength decays rapidly with distance and it can be necessary to utilize larger (several kg) quantities of explosive to prevent significant decay from occurring before an idealized blast wave has formed. Such a mode of testing can be expensive, require large quantities of explosive, and be limited by both atmospheric conditions (such as rain) and by noise complaints from the population density near the test arena. Testing is possible in more compact geometries, however. Non-planar blast waves can be formed into a quasi-planar shape by confining the shock diffraction with the walls of a shock tube. Regardless of the initial form, the wave shape will begin to approximate a planar front after successive wave reflections from the tube

  6. Joint analysis of infrasound and seismic signals by cross wavelet transform: detection of Mt. Etna explosive activity

    Directory of Open Access Journals (Sweden)

    A. Cannata


    Full Text Available The prompt detection of explosive volcanic activity is crucial since this kind of activity can release copious amounts of volcanic ash and gases into the atmosphere, causing severe dangers to aviation. In this work, we show how the joint analysis of seismic and infrasonic data by wavelet transform coherence (WTC can be useful to detect explosive activity, significantly enhancing its recognition that is normally done by video cameras and thermal sensors. Indeed, the efficiency of these sensors can be reduced (or inhibited in the case of poor visibility due to clouds or gas plumes. In particular, we calculated the root mean square (RMS of seismic and infrasonic signals recorded at Mt. Etna during 2011. This interval was characterised by several episodes of lava fountains, accompanied by lava effusion, and minor strombolian activities. WTC analysis showed significantly high values of coherence between seismic and infrasonic RMS during explosive activity, with infrasonic and seismic series in phase with each other, hence proving to be sensitive to both weak and strong explosive activity. The WTC capability of automatically detecting explosive activity was compared with the potential of detection methods based on fixed thresholds of seismic and infrasonic RMS. Finally, we also calculated the cross correlation function between seismic and infrasonic signals, which showed that the wave types causing such seismo-acoustic relationship are mainly incident seismic and infrasonic waves, likely with a common source.


    Directory of Open Access Journals (Sweden)

    A. Levin Vladimir


    Full Text Available This problem is related to the safety problem in the area of forest fires. It is well known that is possible to extinguish a fire, for example, by means of a powerful air stream. Such flow arises from the explosive shock wave. To enhance the im- pact of the blast wave can be used an explosive charge of annular shape. The shock wave, produced by the explosion, in- creased during moves to the center and can serve as a means of transportation dust in the seat of the fire. In addition, emerging after the collapse of a converging shock wave strong updraft can raise dust on a greater height and facilitate fire extinguishing, precipitating dust over a large area. This updraft can be dangerous for aircraft that are in the sky above the fire. To determine the width and height of the danger zone performed the numerical simulation of the ring of the explosion and the subsequent movement of dust and gas mixtures. The gas is considered ideal and perfect. The explosion is modeled as an instantaneous increase in the specific internal energy in an annular zone on the value of the specific heat of explosives. The flow is consid- ered as two-dimensional, and axisymmetric. The axis of symmetry perpendicular to the Earth surface. This surface is considered to be absolutely rigid and is considered as the boundary of the computational domain. On this surface is exhibited the condition of no motion. For the numerical method S. K. Godunov is used a movable grid. One system of lines of this grid is moved in accordance with movement of the shock wave. Others lines of this grid are stationary. The calculations were per- formed for different values of the radii of the annular field and for different sizes of rectangular cross-sectional of the annular field. Numerical results show that a very strong flow is occurring near the axis of symmetry and the particles rise high above the surface. These calculations allow us to estimate the sizes of the zone of danger in specific

  8. Inelastic processes in seismic wave generation by underground explosions

    Energy Technology Data Exchange (ETDEWEB)

    Rodean, H.C.


    Theories, computer calculations, and measurements of spherical stress waves from explosions are described and compared, with emphasis on the transition from inelastic to almost-elastic relations between stress and strain. Two aspects of nonspherical explosion geometry are considered: tectonic strain release and surface spall. Tectonic strain release affects the generation of surface waves; spall closure may also. The reduced-displacement potential is a common solution (the equivalent elastic source) of the forward and inverse problems, assuming a spherical source. Measured reduced-displacement potentials are compared with potentials calculated as solutions of the direct and inverse problems; there are significant differences between the results of the two types of calculations and between calculations and measurements. The simple spherical model of an explosion is not sufficient to account for observations of explosions over wide ranges of depth and yield. The explosion environment can have a large effect on explosion detection and yield estimation. The best sets of seismic observations for use in developing discrimination techniques are for high-magnitude high-yield explosions; the identification problem is most difficult for low-magnitude low-yield explosions. Most of the presently available explosion data (time, medium, depth, yield, etc.) are for explosions in a few media at the Nevada Test Site; some key questions concerning magnitude vs yield and m/sub b/ vs M/sub s/ relations can be answered only by data for explosions in other media at other locations.

  9. Seismic and source characteristics of large chemical explosions. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Adushkin, V.V.; Kostuchenko, V.N.; Pernik, L.M.; Sultanov, D.D.; Zcikanovsky, V.I.


    From the very beginning of its arrangement in 1947, the Institute for Dynamics of the Geospheres RAS (former Special Sector of the Institute for physics of the Earth, RAS) was providing scientific observations of effects of nuclear explosions, as well as large-scale detonations of HE, on environment. This report presents principal results of instrumental observations obtained from various large-scale chemical explosions conducted in the Former-Soviet Union in the period of time from 1957 to 1989. Considering principal aim of the work, tamped and equivalent chemical explosions have been selected with total weights from several hundreds to several thousands ton. In particular, the selected explosions were aimed to study scaling law from excavation explosions, seismic effect of tamped explosions, and for dam construction for hydropower stations and soil melioration. Instrumental data on surface explosions of total weight in the same range aimed to test military technics and special objects are not included.

  10. Numerical simulation of explosive welding using Smoothed Particle Hydrodynamics method

    Directory of Open Access Journals (Sweden)

    J Feng


    Full Text Available In order to investigate the mechanism of explosive welding and the influences of explosive welding parameters on the welding quality, this paper presents numerical simulation of the explosive welding of Al-Mg plates using Smoothed Particle Hydrodynamics method. The multi-physical phenomena of explosive welding, including acceleration of the flyer plate driven by explosive detonation, oblique collision of the flyer and base plates, jetting phenomenon and the formation of wavy interface can be reproduced in the simulation. The characteristics of explosive welding are analyzed based on the simulation results. The mechanism of wavy interface formation is mainly due to oscillation of the collision point on the bonding surfaces. In addition, the impact velocity and collision angle increase with the increase of the welding parameters, such as explosive thickness and standoff distance, resulting in enlargement of the interfacial waves.

  11. One-Dimensional Time to Explosion (Thermal Sensitivity) of ANPZ

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hust, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McClelland, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gresshoff, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)


    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 explosion, threshold thermal explosion temperature, and determine kinetic parameters 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 recent ODTX experimental data and modeling results for 2,6-diamino-3,5-dintropyrazine (ANPZ).

  12. Specific features of explosive decomposition of pentaerythritol tetranitrate exposed to an electron beam with an explosive emission cathode (United States)

    Aduev, B. P.; Belokurov, G. M.; Krechetov, A. G.; Liskov, I. Yu.


    A comparative examination of the critical energy density of explosive decomposition of pentaerythritol tetranitrate exposed either to an electron beam of a GIN-600 accelerator (240 keV, 20 ns) with an explosive emission cathode or to this beam combined with metal low-temperature diode plasma has been performed. It has been demonstrated that the contribution of plasma to the development of explosive decomposition is appreciable at explosion probabilities P ≤ 0.2. At higher energy densities and explosion probabilities P ≥ 0.5, the contribution of plasma to the overall beam energy density did not exceed 10%.

  13. Seismic explosion sources on an ice cap

    DEFF Research Database (Denmark)

    Shulgin, Alexey; Thybo, Hans


    Controlled source seismic investigation of crustal structure below ice covers is an emerging technique. We have recently conducted an explosive refraction/wide-angle reflection seismic experiment on the ice cap in east-central Greenland. The data-quality is high for all shot points and a full...... crustal model can be modelled. A crucial challenge for applying the technique is to control the sources. Here, we present data that describe the efficiency of explosive sources in the ice cover. Analysis of the data shows, that the ice cap traps a significant amount of energy, which is observed...... as a strong ice wave. The ice cap leads to low transmission of energy into the crust such that charges need be larger than in conventional onshore experiments to obtain reliable seismic signals. The strong reflection coefficient at the base of the ice generates strong multiples which may mask for secondary...

  14. Initiation and Propagation in Primary Explosives (United States)

    Dickson, P. M.; Field, J. E.


    The initiation and propagation of deflagration and detonation in mercury fulminate, lead azide, mercuric-5-nitrotetrazole and silver-5-nitrotetrazole have been studied using various techniques. Streak and framing high-speed photography were used to observe these events directly. The main aim has been to investigate the factors which affect deflagration-to-detonation transition (DDT) and the related phenomenon of dead-pressing, which may be regarded as a failure of the DDT process at high pressed densities. These factors include the variable properties of pressed density, void structure, confinement and charge dimension and geometry, and also fixed properties (for a given explosive) such as shock and thermal sensitivities, heat of explosion and the quantity and state of the reaction products. The nature and strength of the initiating stimulus also have a major effect on the subsequent reaction.

  15. Ignitability and explosibility of gases and vapors

    CERN Document Server

    Ma, Tingguang


    The book provides a systematic view on flammability and a collection of solved engineering problems in the fields of dilution and purge, mine gas safety, clean burning safety and gas suppression modeling. For the first time, fundamental principles of energy conservation are used to develop theoretical flammability diagrams and are then explored to understand various safety-related mixing problems. This provides the basis for a fully-analytical solution to any flammability problem. Instead of the traditional view that flammability is a fundamental material property, here flammability is discovered to be a result of the explosibility of air and the ignitability of fuel, or a process property. By exploring the more fundamental concepts of explosibility and ignitability, the safety targets of dilution and purge can be better defined and utilized for guiding safe operations in process safety. This book provides various engineering approaches to mixture flammability, benefiting not only the safety students, but al...

  16. Study on Explosive Forming of Aluminum Alloy

    Directory of Open Access Journals (Sweden)

    H Iyama


    Full Text Available Now, the aluminum alloy is often used as auto parts, for example, body, engine. For example, there are the body, a cylinder block, a piston, a connecting rod, interior, exterior parts, etc. These are practical used the characteristic of a light and strong aluminum alloy efficiently. However, although an aluminum alloy is lighter than steel, the elongation is smaller than that. Therefore, in press forming, some problems often occur. We have proposed use of explosive forming, in order to solve this problem. In the explosive forming, since a blank is formed at high speed, a strain rate effect becomes large and it can be made the elongation is larger. Then, in order to clarify this feature, we carried out experimental research and numerical analysis. In this paper, these contents will be discussed.

  17. Lower head integrity under steam explosion loads

    Energy Technology Data Exchange (ETDEWEB)

    Theofanous, T.G.; Yuen, W.W.; Angelini, S.; Freeman, K.; Chen, X.; Salmassi, T. [Center for Risk Studies and Safety, Univ. of California, Santa Barbara, CA (United States); Sienicki, J.J.


    Lower head integrity under steam explosion loads in an AP600-like reactor design is considered. The assessment is the second part of an evaluation of the in-vessel retention idea as a severe accident management concept, the first part (DOE/ID-10460) dealing with thermal loads. The assessment is conducted in terms of the Risk Oriented Accident Analysis Methodology (ROAAM), and includes the comprehensive evaluation of all relevant severe accident scenarios, melt conditions and timing of release from the core region, fully 3D mixing and explosion wave dynamics, and lower head fragility under local, dynamic loading. All of these factors and brought together in a ROAAM Probabilistic Framework to evaluate failure likelihood. The conclusion is that failure is `physically unreasonable`. (author)

  18. The First Man-Made Nuclear Explosion (United States)

    Worth Seagondollar, L.


    This talk is part Nuclear Physics, part description of the greatest war-time experience possible for a young graduate student, and part eye-witness description of the 1945 plutonium fission devise explosion in the New Mexico desert. Living and working in the secret Manhattan District laboratory was truly unique. Hearing talks by Nobel Laureates (past & future), participating in nuclear experiments that determined the critical masses for U-235 and Pu-239, having near-catastrophic accidents, working with an armed guard watching you, having Enrico Fermi ask you to come to his office--these are unforgettable memories. There will be a description of 3 days in the New Mexico desert and a description of the early morning nuclear explosion at the Trinity Site and a description of that Site 30 days later.

  19. SERS substrate for detection of explosives. (United States)

    Chou, Alison; Jaatinen, Esa; Buividas, Ricardas; Seniutinas, Gediminas; Juodkazis, Saulius; Izake, Emad L; Fredericks, Peter M


    A novel gold coated femtosecond laser nanostructured sapphire surface - an "optical nose" - based on surface-enhanced Raman spectroscopy (SERS) for detecting vapours of explosive substances was investigated. Four different nitroaromatic vapours at room temperature were tested. Sensor responses were unambiguous and showed response in the range of 0.05-15 μM at 25 °C. The laser fabricated substrate nanostructures produced up to an eight-fold increase in Raman signal over that observed on the unstructured portions of the substrate. This work demonstrates a simple sensing system that is compatible with commercial manufacturing practices to detect taggants in explosives which can undertake as part of an integrated security or investigative mission.

  20. Quantum cascade laser FM spectroscopy of explosives (United States)

    Gutmann, Zach; Clasp, Trocia; Lue, Chris; Johnson, Tiffani; Ingle, Taylor; Jamison, Janet; Buchanan, Roger; Reeve, Scott


    Polyisobutylene is an industrial polymer that is widely used in a number of applications including the manufacture of military grade explosives. We have examined the vapor emanating from a series of different molecular weight samples of polyisobutylene using high resolution Quantum Cascade Laser FM spectroscopy. The vapor phase spectra all exhibit a rovibrational structure similar to that for the gas phase isobutylene molecule. We have assigned the structure in the 890 cm-1 and 1380 cm-1 regions to the isobutylene ν28 and ν7 fundamental bands respectively. These spectroscopic signatures may prove useful for infrared sensing applications. Here we will present the infrared signatures along with recent GCMS data from a sample of C4, utilizing solid-phase microextraction vapor collection fibers, which confirm the presence of isobutylene as one of the volatile bouquet species in RDX-based explosives.

  1. Explosive magnetorotational instability in Keplerian disks

    Energy Technology Data Exchange (ETDEWEB)

    Shtemler, Yu., E-mail:; Liverts, E., E-mail:; Mond, M., E-mail: [Department of Mechanical Engineering, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel)


    Differentially rotating disks under the effect of axial magnetic field are prone to a nonlinear explosive magnetorotational instability (EMRI). The dynamic equations that govern the temporal evolution of the amplitudes of three weakly detuned resonantly interacting modes are derived. As distinct from exponential growth in the strict resonance triads, EMRI occurs due to the resonant interactions of an MRI mode with stable Alfvén–Coriolis and magnetosonic modes. Numerical solutions of the dynamic equations for amplitudes of a triad indicate that two types of perturbations behavior can be excited for resonance conditions: (i) EMRI which leads to infinite values of the three amplitudes within a finite time, and (ii) bounded irregular oscillations of all three amplitudes. Asymptotic explicit solutions of the dynamic equations are obtained for EMRI regimes and are shown to match the numerical solutions near the explosion time.

  2. Electronic Nose for Detection of Explosives. (United States)

    Oakes, Landon; Dobrokhotov, Vladimir


    The ability to sense the environment is of critical importance for a broad array of applications ranging from ecosystem health, hazardous materials avoidance/chemical warfare to medical applications. In this research project we use the self-assembled monolayer (SAM)-functionalized nanoparticle-decorated nanosprings as a novel design for sensing vapors associated with explosives. The common requirements for any sensor application are sensitivity, selectivity, refreshability, repeatability, low cost of manufacture, and ease of use. The project goal is to answer these needs through the use of mats of functionalized metal nanoparticle-coated nanosprings as a novel type of low-cost nanomaterials-based gas sensor. The advantage of this approach is that very dilute quantities of airborne explosive products can be accumulated over a few seconds to a few minutes onto our high surface area nanospring electrodes. This will facilitate electronic detection, which in contrast to optical detection methods reduces false positive signals, reduces detector sizes and complexity.

  3. Facial trauma caused by electronic cigarette explosion. (United States)

    Vaught, Brian; Spellman, Joseph; Shah, Anil; Stewart, Alexander; Mullin, David


    Electronic cigarettes are increasingly popular as a supposed safer alternative to tobacco cigarettes or a smoking cessation tool. Research and debate have focused primarily on possible adverse effects caused by the inhaled aerosol produced by electronic cigarettes and on smoking cessation efficacy. Few reports in the medical literature describe injuries secondary to device malfunction. We present a case of electronic cigarette explosion, with a projectile fracturing the patient's right naso-orbital-ethmoid complex and anterior and posterior frontal sinus tables, with frontal sinus outflow tract involvement. The patient underwent combined open and endoscopic repair, including open reduction internal fixation, with reconstitution and preservation of the frontal sinus and frontal sinus outflow tract. Additionally, we review the available data on electronic cigarette malfunction-including fires, explosions, associated injuries, and possible reasons for device malfunction-and discuss new 2016 U.S. Food and Drug Administration regulations pertaining to electronic cigarettes.

  4. The November 2009 paroxysmal explosions at Stromboli (United States)

    Andronico, Daniele; Pistolesi, Marco


    Two paroxysmal explosions occurred at Stromboli volcano (Italy) on 8 and 24 November 2009. Analysis of recordings (from video-camera surveillance) indicates that each paroxysm consisted of multiple bursts from different vents. Field surveys, carried out within a few days after the two paroxysmal events, allowed us to gather crucial data on eruptive deposits and document morphological variations occurring at the source vents. Integration of video-analysis and field observations allowed making inferences on the eruptive dynamics of each explosive paroxysm. The 24 November event, in particular, erupted a larger volume and coarser products dispersed further from the summit area, resulting in a more hazardous event compared to the 8 November event that was largely confined to the upper part of the volcano.

  5. Detecting underwater improvised explosive threats (DUIET) (United States)

    Feeley, Terry


    Improvised Explosive Devices (IEDs) have presented a major threat in the wars in Afghanistan and Iraq. These devices are powerful homemade land mines that can be small and easily hidden near roadsides. They are then remotely detonated when Coalition Forces pass by either singly or in convoys. Their rapid detection, classification and destruction is key to the safety of troops in the area. These land based bombs will have an analogue in the underwater theater especially in ports, lakes, rivers and streams. These devices may be used against Americans on American soil as an element of the global war on terrorism (GWOT) Rapid detection and classification of underwater improvised explosive devices (UIED) is critical to protecting innocent lives and maintaining the day to day flow of commerce. This paper will discuss a strategy and tool set to deal with this potential threat.

  6. DOE explosives safety manual. Revision 7

    Energy Technology Data Exchange (ETDEWEB)


    This manual prescribes the Department of Energy (DOE) safety rules used to implement the DOE safety policy for operations involving explosives. This manual is applicable to all DOE facilities engaged in operations of development, manufacturing, handling, storage, transportation, processing, or testing of explosives, pyrotechnics and propellants, or assemblies containing these materials. The standards of this manual deal with the operations involving explosives, pyrotechnics and propellants, and the safe management of such operations. The design of all new explosives facilities shall conform to the requirements established in this manual and implemented in DOE 6430.1A, ``General Design Criteria Manual.`` It is not intended that existing physical facilities be changed arbitrarily to comply with these provisions, except as required by law. Existing facilities that do not comply with these standards may continue to be used for the balance of their functional life, as long as the current operation presents no significantly greater risk than that assumed when the facility was originally designed and it can be demonstrated clearly that a modification to bring the facility into compliance is not feasible. However, in the case of a major renovation, the facility must be brought into compliance with current standards. The standards are presented as either mandatory or advisory. Mandatory standards, denoted by the words ``shall,`` ``must,`` or ``will,`` are requirements that must be followed unless written authority for deviation is granted as an exemption by the DOE. Advisory standards denoted by ``should`` or ``may`` are standards that may be deviated from with a waiver granted by facility management.

  7. Risk-Based Explosive Safety Analysis (United States)


    REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1...currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) 30 November 2016 2. REPORT TYPE...Technical Paper 3. DATES COVERED (From - To) 01 November 2016 – 30 November 2016 4. TITLE AND SUBTITLE Risk-Based Explosive Safety Analysis 5a

  8. Explosive Infrasonic Events: Sensor Comparison Experiment (SCE)

    Energy Technology Data Exchange (ETDEWEB)

    Schnurr, J. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Garces, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Rodgers, A. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)


    SCE (sensor comparison experiment) 1 through 4 consists of a series of four controlled above-ground explosions designed to provide new data for overpressure propagation. Infrasound data were collected by LLNL iPhones and other sensors. Origin times, locations HOB, and yields are not being released at this time and are therefore not included in this report. This preliminary report will be updated as access to additional data changes, or instrument responses are determined.

  9. Surface detonation in type Ia supernova explosions?


    Roepke, F. K.; Woosley, S. E.


    We explore the evolution of thermonuclear supernova explosions when the progenitor white dwarf star ignites asymmetrically off-center. Several numerical simulations are carried out in two and three dimensions to test the consequences of different initial flame configurations such as spherical bubbles displaced from the center, more complex deformed configurations, and teardrop-shaped ignitions. The burning bubbles float towards the surface while releasing energy due to the nuclear reactions. ...

  10. Polyurethane Binder Systems for Polymer Bonded Explosives (United States)


    Trimethylol propane TPB Triphenyl Bismuth DSTO-GD-0492 1. Introduction The desire for increased safety in explosives handling, storage and...HTPB) 7.346 Dioctyl adipate (DOA) 7.346 Antioxidant 2246 (AO) 0.10 N,N 2-Hydroxyethyl dimethyl-hydantoin (DHE) 0.26 Triphenyl bismuth (TBP) 0.02...with water and the liberated acetic acid is titrated against 0.5 N alcoholic potassium hydroxide solution. The following solutions are required

  11. Explosive detection technologies for airline security


    Maruyama, Xavier K.


    Aviation safety and security has become a topic of paramount national concern. Informed decision making requires an appreciation of trends in technology in response to projected future terrorist activities. In the area of security, explosive detection is made possible by a bewildering array of newly offered equipment. This document describes the science and engineering of the various technologies. The information presented here was written for airline security, but it applies also to a wi...

  12. Optimization of Composting for Explosives Contaminated Soil (United States)


    required for implementation of j composting as a cost- effective alternative to incineration. All three explosives present at UMDA demonstrated...into the mixture to be composted and/or the contaminants must be degraded at a higher rate. To increase the rates of degradation either more effective ...microorganisms with more effective metabolic pathways/enzymes are available and will function well in a compost matrix), optimizing the composition of the

  13. Composting of Explosives-Contaminated Soil Technology (United States)


    dinitrotoluenes) and to evaluate the influence of temperature upon composting effectiveness . This study demonstrated that the bioconversion of explosives under... effected primarily by mechanical turning of the compost , clcsely regulated temperature regimes in such a system may be difficult to achieve. In aerated...treatment processes, the feasibility and economics of composting will be directly influenced by the length of time required for treatment. Treatment

  14. Dynamic Fracture Simulations of Explosively Loaded Cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Arthur, Carly W. [Univ. of California, Davis, CA (United States). Dept. of Civil and Environmental Engineering; Goto, D. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)


    This report documents the modeling results of high explosive experiments investigating dynamic fracture of steel (AerMet® 100 alloy) cylinders. The experiments were conducted at Lawrence Livermore National Laboratory (LLNL) during 2007 to 2008 [10]. A principal objective of this study was to gain an understanding of dynamic material failure through the analysis of hydrodynamic computer code simulations. Two-dimensional and three-dimensional computational cylinder models were analyzed using the ALE3D multi-physics computer code.

  15. Youngest Stellar Explosion in Our Galaxy Discovered (United States)


    Astronomers have found the remains of the youngest supernova, or exploded star, in our Galaxy. The supernova remnant, hidden behind a thick veil of gas and dust, was revealed by the National Science Foundation's Very Large Array (VLA) and NASA's Chandra X-Ray Observatory, which could see through the murk. The object is the first example of a "missing population" of young supernova remnants. 1985 and 2008 VLA Images Move cursor over image to blink. VLA Images of G1.9+0.3 in 1985 and 2008: Circle for size comparison. CREDIT: Green, et al., NRAO/AUI/NSF From observing supernovae in other galaxies, astronomers have estimated that about three such stellar explosions should occur in our Milky Way every century. However, the most recent one known until now occurred around 1680, creating the remnant called Cassiopeia A. The newly-discovered object is the remnant of an explosion only about 140 years ago. "If the supernova rate estimates are correct, there should be the remnants of about 10 supernova explosions in the Milky Way that are younger than Cassiopeia A," said David Green of the University of Cambridge in the UK, who led the VLA study. "It's great to finally track one of them down." Supernova explosions, which mark the violent death of a star, release tremendous amounts of energy and spew heavy elements such as calcium and iron into interstellar space. They thus seed the clouds of gas and dust from which new stars and planets are formed and, through their blast shocks, can even trigger such formation. The lack of evidence for young supernova remnants in the Milky Way had caused astronomers to wonder if our Galaxy, which appears otherwise normal, differed in some unknown way from others. Alternatively, scientists thought that the "missing" Milky Way supernovae perhaps indicated that their understanding of the relationship between supernovae and other galactic processes was in error. The astronomers made their discovery by measuring the expansion of the debris from

  16. Synthesis of Magnetized Nuclei at Supernova Explosion (United States)

    Kondratyev, V. N.; Nurtayeva, U. M.; Zhomartova, A. Zh.; Mishenina, T. V.

    Influence of magnetorotational instabilities in astrophysical plasma at supernova explosion on synthesis of chemical elements is investigated. At field strength less than 10 teratesla nuclear magnetic susceptibility exhibits linear regime with enhanced nuclear binding energy for open shell nuclei. Effects of ultra-strong nuclear magnetization are demonstrated to enhance the portion of titanium product. The relation to an excess of titanium isotopes revealed from the Integral mission data and galactic chemical evolution is discussed.

  17. Radioactive Beam Measurements to Probe Stellar Explosions

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Michael Scott [ORNL


    Unique beams of unstable nuclei from the Holi eld Radioactive Ion Beam Facility at Oak Ridge National Laboratory are being used to measure the thermonuclear reactions that occur in novae, X-ray bursts, and supernovae. The astrophysical impact of these measurements is determined by synergistic nuclear data evaluations and element synthesis calculations. Results of recent measurements and explosion simulations are brie y described, along with future plans and software research tools for the community.

  18. The Biggest Explosions in the Universe

    Indian Academy of Sciences (India)

    G am m a ray bursts { w hich are ¯rst detected in energetic gam m a rays and w hich then glow in. X -ray, visible and radio w avelengths { are the result of the biggest explosions in the universe. A stronom ers w onder w hat causes these violent events, and som e of their ideas are discussed in th is article. 1. S eren d ip itou s ...

  19. Some properties of explosive mixtures containing peroxides

    Energy Technology Data Exchange (ETDEWEB)

    Zeman, Svatopluk [Institute of Energetic Materials, Faculty of Chemical Technology, University of Pardubice, CZ-532 10 Pardubice (Czech Republic)], E-mail:; Trzcinski, Waldemar A. [Institute of Chemistry, Military University of Technology, PL-00-908 Warsaw 49 (Poland); Matyas, Robert [Institute of Energetic Materials, Faculty of Chemical Technology, University of Pardubice, CZ-532 10 Pardubice (Czech Republic)


    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, E{sub 0}, 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 E{sub 0} 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{sup -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.

  20. High Voltage Application of Explosively Formed Fuses

    Energy Technology Data Exchange (ETDEWEB)

    Tasker, D.G.; Goforth, J.H.; Fowler, C.M.; Lopez, E.M.; Oona, H.; Marsh, S.P.; King, J.C.; Herrera, D.H.; Torres, D.T.; Sena, F.C.; Martinez, E.C.; Reinovsky, R.E.; Stokes, J.L.; Tabaka, L.J.; Kiuttu, G.; Degnan, J.


    At Los Alamos, the authors have primarily applied Explosively Formed Fuse (EFF) techniques to high current systems. In these systems, the EFF has interrupted currents from 19 to 25 MA, thus diverting the current to low inductance loads. The magnitude of transferred current is determined by the ratio of storage inductance to load inductance, and with dynamic loads, the current has ranged from 12 to 20 MA. In a system with 18 MJ stored energy, the switch operates at a power up to 6 TW. The authors are now investigating the use of the EFF technique to apply high voltages to high impedance loads in systems that are more compact. In these systems, they are exploring circuits with EFF lengths from 43 to 100 cm, which have storage inductances large enough to apply 300 to 500 kV across high impedance loads. Experimental results and design considerations are presented. Using cylindrical EFF switches of 10 cm diameter and 43 cm length, currents of approximately 3 MA were interrupted producing {approximately}200 kV. This indicate s the switch had an effective resistance of {approximately}100 m{Omega} where 150--200 m{Omega} was expected. To understand the lower performance, several parameters were studied, including: electrical conduction through the explosive products; current density; explosive initiation; insulator type; conductor thickness; and so on. The results show a number of interesting features, most notably that the primary mechanism of switch operation is mechanical and not electrical fusing of the conductor. Switches opening on a 10 to 10 {micro}s time scale with resistances starting at 50 {micro}{Omega} and increasing to perhaps 1 {Omega} now seem possible to construct, using explosive charges as small as a few pounds.

  1. Nitroaromatic explosives detection using electrochemically exfoliated graphene (United States)

    Yew, Ying Teng; Ambrosi, Adriano; Pumera, Martin


    Detection of nitroaromatic explosives is of paramount importance from security point of view. Graphene sheets obtained from the electrochemical anodic exfoliation of graphite foil in different electrolytes (LiClO4 and Na2SO4) were compared and tested as electrode material for the electrochemical detection of 2,4-dinitrotoluene (DNT) and 2,4,6-trinitrotoluene (TNT) in seawater. Voltammetry analysis demonstrated the superior electrochemical performance of graphene produced in LiClO4, resulting in higher sensitivity and linearity for the explosives detection and lower limit of detection (LOD) compared to the graphene obtained in Na2SO4. We attribute this to the presence of oxygen functionalities onto the graphene material obtained in LiClO4 which enable charge electrostatic interactions with the -NO2 groups of the analyte, in addition to π-π stacking interactions with the aromatic moiety. Research findings obtained from this study would assist in the development of portable devices for the on-site detection of nitroaromatic explosives.

  2. Explosive microfractures induced by K-metasomatism (United States)

    Xu, Xing-Wang; Cai, Xin-Ping; Zhang, Bao-Lin; Wang, Jie


    Ultra-fine mineral aggregates in K-metasomatic rocks of the Hougou area, northwestern Hebei Province, China contain peculiar and distinct intergranular and intragranular geometries, compositions, and textures. These features indicate solidification of expanded and enclosed relict fluids within tensile microfractures. Two basic morphologic types of textures are present: saw-toothed and wheel-shaped, and several composite patterns also are present, such as X-shaped, grid, and network. The appearance of these features indicate explosion from an instantaneous force. These microscopic explosive microfractures are directly related to the enclosed relict fluids. Theoretical estimates show that volume expansion induced by mineral replacements during K-metasomatism may have caused the K-metasomatic fluids to be confined and strongly compressed in order to build up powerful forces that produced the ultra-fine mineral aggregates and explosive microfractures. The thick-walled texture of K-metasomatic rocks confined fractures that propagated only in the replaced rocks with the lowest strength. Both pumping pressures and the propagation of the K-metasomatism were self-governed and controlled by introduced chemical elements, specially K +.

  3. Explosive Detection in Aviation Applications Using CT

    Energy Technology Data Exchange (ETDEWEB)

    Martz, H E; Crawford, C R


    CT scanners are deployed world-wide to detect explosives in checked and carry-on baggage. Though very similar to single- and dual-energy multi-slice CT scanners used today in medical imaging, some recently developed explosives detection scanners employ multiple sources and detector arrays to eliminate mechanical rotation of a gantry, photon counting detectors for spectral imaging, and limited number of views to reduce cost. For each bag scanned, the resulting reconstructed images are first processed by automated threat recognition algorithms to screen for explosives and other threats. Human operators review the images only when these automated algorithms report the presence of possible threats. The US Department of Homeland Security (DHS) has requirements for future scanners that include dealing with a larger number of threats, higher probability of detection, lower false alarm rates and lower operating costs. One tactic that DHS is pursuing to achieve these requirements is to augment the capabilities of the established security vendors with third-party algorithm developers. A third-party in this context refers to academics and companies other than the established vendors. DHS is particularly interested in exploring the model that has been used very successfully by the medical imaging industry, in which university researchers develop algorithms that are eventually deployed in commercial medical imaging equipment. The purpose of this paper is to discuss opportunities for third-parties to develop advanced reconstruction and threat detection algorithms.

  4. Development of steam explosion simulation code JASMINE

    Energy Technology Data Exchange (ETDEWEB)

    Moriyama, Kiyofumi; Yamano, Norihiro; Maruyama, Yu; Kudo, Tamotsu; Sugimoto, Jun [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Nagano, Katsuhiro; Araki, Kazuhiro


    A steam explosion is considered as a phenomenon which possibly threatens the integrity of the containment vessel of a nuclear power plant in a severe accident condition. A numerical calculation code JASMINE (JAeri Simulator for Multiphase INteraction and Explosion) purposed to simulate the whole process of steam explosions has been developed. The premixing model is based on a multiphase flow simulation code MISTRAL by Fuji Research Institute Co. In JASMINE code, the constitutive equations and the flow regime map are modified for the simulation of premixing related phenomena. The numerical solution method of the original code is succeeded, i.e. the basic equations are discretized semi-implicitly, BCGSTAB method is used for the matrix solver to improve the stability and convergence, also TVD scheme is applied to capture a steep phase distribution accurately. Test calculations have been performed for the conditions correspond to the experiments by Gilbertson et al. and Angelini et al. in which mixing of solid particles and water were observed in iso-thermal condition and with boiling, respectively. (author).

  5. Characteristics of regional seismic waves from large explosive events including Korean nuclear explosions (United States)

    Jo, Eunyoung; Lee, Ha-sung


    Three North Korean underground nuclear explosion (UNE) tests were conducted in 2006, 2009 and 2013. Discrimination of explosions from natural earthquakes is important in monitoring the seismic activity in the Korean Peninsula. The UNEs were well recorded by dense regional seismic networks in South Korea. The UNEs provide unique regional seismic waveforms with high signal-to-noise ratios. However, the continental crust in the Korean Peninsula changes abruptly into a transitional structure between continental and oceanic crusts across the eastern coast. The complex geological and tectonic structures around the Korean Peninsula cause significant variations in regional waveforms. Outstanding question is whether conventional discrimination techniques can be applicable for explosions including the North Korean UNEs. P/S amplitude ratios are widely used for seismic discrimination. To understand the regional shear-energy composition, we analyze the frequency contents of waveforms. The shear-energy contents for the UNEs are compared with those for natural earthquakes with comparable magnitudes. The result shows that the UNEs are successfully discriminated from earthquakes in the Korean Peninsula. We also analyze the explosive events from North Korean not UNEs to test the applicability of the discrimination technique. The result of high frequency Pn/Sn regional discrimination in the explosions show that as magnitude of event is smaller, available distance of discrimination is decreased particularly in high frequency range. The poor signal to noise ratio of Pn phase in the explosions, and inefficient propagation of Sn phase in the Western part of the peninsula frustrate Pn/Sn discriminant, while the UNEs show good performance using both discriminants because of propagation path effects in the eastern part of the peninsula.

  6. Nonlinear synthesis of infrasound propagation through an inhomogeneous, absorbing atmosphere. (United States)

    de Groot-Hedlin, C D


    An accurate and efficient method to predict infrasound amplitudes from large explosions in the atmosphere is required for diverse source types, including bolides, volcanic eruptions, and nuclear and chemical explosions. A finite-difference, time-domain approach is developed to solve a set of nonlinear fluid dynamic equations for total pressure, temperature, and density fields rather than acoustic perturbations. Three key features for the purpose of synthesizing nonlinear infrasound propagation in realistic media are that it includes gravitational terms, it allows for acoustic absorption, including molecular vibration losses at frequencies well below the molecular vibration frequencies, and the environmental models are constrained to have axial symmetry, allowing a three-dimensional simulation to be reduced to two dimensions. Numerical experiments are performed to assess the algorithm's accuracy and the effect of source amplitudes and atmospheric variability on infrasound waveforms and shock formation. Results show that infrasound waveforms steepen and their associated spectra are shifted to higher frequencies for nonlinear sources, leading to enhanced infrasound attenuation. Results also indicate that nonlinear infrasound amplitudes depend strongly on atmospheric temperature and pressure variations. The solution for total field variables and insertion of gravitational terms also allows for the computation of other disturbances generated by explosions, including gravity waves.

  7. Sayarim Infrasound Calibration Explosion: conducting, near-source and local observations (United States)

    Gitterman, Y.; Hofstetter, A.


    The large-scale calibration explosion was successfully conducted by the Geophysical Institute of Israel at Sayarim Military Range on 26 August 2009 (detonation time 6:31:54.0 GMT, coordinates 30.00057°N, 34.81351°E). A charge of about 82 tons of HE explosives, assembled as a pyramid on the soft sediment surface, was detonated upwards. High-pressures and strong ground motions in the range 70-600 m were measured, and speed video recording was done. Preliminary analysis showed higher recorded peak pressures than estimated values, whereas the created crater and seismic magnitude (by Israel Seismic Network) were smaller than expected for this on-surface charge. These results confirm that the charge design provided necessary explosion energy generation and partition: maximum of the energy to the atmosphere and minimum to the ground. The primary goal of this calibration experiment was reached: infrasound signals were observed at numerous stations in Israel, the Mediterranean and Europe, including IMS stations, at distances up to 3500 km. We present here the charge design features, conducting procedures, the analysis of high-pressure, accelerometer and speed video recordings, and seismic and infrasound observations at Israel stations, in the range 0.1-360 km.

  8. Spallation reactions in shock waves at supernova explosions and related problems (United States)

    Ustinova, G. K.


    The isotopic anomalies of some extinct radionuclides testify to the outburst of a nearby supernova just before the collapse of the protosolar nebula, and to the fact that the supernova was Sn Ia, i.e. the carbon-detonation supernova. A key role of spallation reactions in the formation of isotopic anomalies in the primordial matter of the Solar System is revealed. It is conditioned by the diffusive acceleration of particles in the explosive shock waves, which leads to the amplification of rigidity of the energy spectrum of particles and its enrichment with heavier ions. The quantitative calculations of such isotopic anomalies of many elements are presented. It is well-grounded that the anomalous Xe- HL in meteoritic nanodiamonds was formed simultaneously with nanodiamonds themselves during the shock wave propagation at the Sn Ia explosion. The possible effects of shock wave fractionation of noble gases in the atmosphere of planets are considered. The origin of light elements Li, Be and B in spallation reactions, predicted by Fowler in the middle of the last century, is argued. All the investigated isotopic anomalies give the evidence for the extremely high magneto- hydrodynamics (MHD) conditions at the initial stage of free expansion of the explosive shock wave from Sn Ia, which can be essential in solution of the problem of origin of cosmic rays. The specific iron-enriched matter of Sn Ia and its MHD-separation in turbulent processes must be taking into account in the models of origin of the Solar System.

  9. Radionuclide observables for the Platte underground nuclear explosive test on 14 April 1962. (United States)

    Burnett, Jonathan L; Milbrath, Brian D


    Past nuclear weapon explosive tests provide invaluable information for understanding the radionuclide observables expected during an On-site Inspection (OSI) for the Comprehensive Nuclear-Test-Ban Treaty (CTBT). These radioactive signatures are complex and subject to spatial and temporal variability. The Platte underground nuclear explosive test on 14 April 1962 provides extensive environmental monitoring data that can be modelled and used to calculate the maximum time available for detection of the OSI-relevant radionuclides. The 1.6 kT test is especially useful as it released the highest amounts of recorded activity during Operation Nougat at the Nevada Test Site - now known as the Nevada National Security Site (NNSS). It has been estimated that 0.36% of the activity was released, and dispersed in a northerly direction. The deposition ranged from 1 × 10-11 to 1 × 10-9 of the atmospheric release (per m2), and has been used in this paper to evaluate an OSI and the OSI-relevant radionuclides at 1 week to 2 years post-detonation. Radioactive decay reduces the activity of the OSI-relevant radionuclides by 99.7% within 2 years of detonation, such that detection throughout the hypothesized inspection is only achievable close to the explosion where deposition was highest. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Supersensitive fingerprinting of explosives by chemically modified nanosensors arrays (United States)

    Lichtenstein, Amir; Havivi, Ehud; Shacham, Ronen; Hahamy, Ehud; Leibovich, Ronit; Pevzner, Alexander; Krivitsky, Vadim; Davivi, Guy; Presman, Igor; Elnathan, Roey; Engel, Yoni; Flaxer, Eli; Patolsky, Fernando


    The capability to detect traces of explosives sensitively, selectively and rapidly could be of great benefit for applications relating to civilian national security and military needs. Here, we show that, when chemically modified in a multiplexed mode, nanoelectrical devices arrays enable the supersensitive discriminative detection of explosive species. The fingerprinting of explosives is achieved by pattern recognizing the inherent kinetics, and thermodynamics, of interaction between the chemically modified nanosensors array and the molecular analytes under test. This platform allows for the rapid detection of explosives, from air collected samples, down to the parts-per-quadrillion concentration range, and represents the first nanotechnology-inspired demonstration on the selective supersensitive detection of explosives, including the nitro- and peroxide-derivatives, on a single electronic platform. Furthermore, the ultrahigh sensitivity displayed by our platform may allow the remote detection of various explosives, a task unachieved by existing detection technologies.

  11. Analysis of the external explosion action on the building barriers

    Directory of Open Access Journals (Sweden)

    Jarosław Siwiński


    Full Text Available The paper presents a method for determination of the action of an external explosion on building barriers. We used different procedures, known in the literature, for analysis of action of an external explosion. These procedures were the basis of tabulated algorithm for determination of the characteristics of the explosion action on the building barriers. We considered the basic division of phases of explosion action onto overpressure phase and underpressure phase. We determined blast wave parameters considering the division of explosion zone onto the close zone and distant zone. For each zone, we presented the methods of determination of the initial pressure of the reflected wave, time durations of overpressure phase, and the load variation in time.[b]Keywords[/b]: civil engineering, structural mechanics, explosive actions, building structures

  12. Characterization of explosives processing waste decomposition due to composting

    Energy Technology Data Exchange (ETDEWEB)

    Griest, W.H.; Tyndall, R.L.; Stewart, A.J.; Ho, C.H.; Ironside, K.S.; Caton, J.E.; Caldwell, W.M.; Tan, E.


    Static pile and mechanically stirred composts generated at the Umatilla Army Depot Activity in a field composting optimization study were chemically and toxicologically characterized to provide data for the evaluation of composting efficiency to decontaminate and detoxify explosives-contaminated soil. Characterization included determination of explosives and 2,4,6,-trinitrotoluene metabolites in composts and their EPA Synthetic Precipitation Leaching Procedure Leachates, leachate toxicity to Ceriodaphnia Dubia and mutagenicity of the leachates and organic solvent extracts of the composts to Ames bacterial strains TA-98 and TA-100. The main conclusion from this study is that composting can effectively reduce the concentrations of explosives and bacterial mutagenicity in explosives -- contaminated soil, and can reduce the aquatic toxicity of leachable compounds. Small levels of explosive and metabolites, bacterial mutagenicity, and leachable aquatic toxicity remain after composting. The ultimate fate of the biotransformed explosives, and the source(s) of residual toxicity and mutagenicity remain unknown.

  13. Blast overpressure after tire explosion: a fatal case. (United States)

    Pomara, Cristoforo; D'Errico, Stefano; Riezzo, Irene; Perilli, Gabriela; Volpe, Umberto; Fineschi, Vittorio


    Fatal blast injuries are generally reported in literature as a consequence of the detonation of explosives in war settings. The pattern of lesion depends on the position of the victim in relation to the explosion, on whether the blast tracks through air or water, and whether it happens in the open air or within an enclosed space and the distance from the explosion. Tire explosion-related injuries are rarely reported in literature. This study presents a fatal case of blast overpressure due to the accidental explosion of a truck tire occurring in a tire repair shop. A multidisciplinary approach to the fatality involving forensic pathologists and engineers revealed that the accidental explosion, which caused a series of primary and tertiary blast wave injuries, was due to tire deterioration.

  14. Atmosphere: Power, Critique, Politics

    DEFF Research Database (Denmark)

    Albertsen, Niels


    This paper hans three interrelated parts. First, atmosphere is approached through the concept of power. Atmospheres 'grip' us directly or mediate power indirectly by manipulating moods and evoking emotions. How does atmosphere relate to different conceptions of power? Second, atmospheric powers may...

  15. Motivation for a High Explosive Testing Program in South Africa (United States)


    1~7JJ!i 5a. DATE: 6a. DATE: 7a. DATE: 8. TITLE: Motivation for a High Explosive Testing Program in South Africa 9. CONTRACT NUMBER: 10...00-00-2015 4. TITLE AND SUBTITLE Motivation for a High Explosive Testing Program in South Africa 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM...600 Raleigh, NC 27605 Contract Number: HDTRA2-11-D-0001 Motivation for a High Explosive Testing Program in South Africa 4

  16. Mesoscale modeling of metal-loaded high explosives

    Energy Technology Data Exchange (ETDEWEB)

    Bdzil, John Bohdan [Los Alamos National Laboratory; Lieberthal, Brandon [UNIV OF ILLINOIS; Srewart, Donald S [UNIV OF ILLINOIS


    We describe a 3D approach to modeling multi-phase blast explosive, which is primarily condensed explosive by volume with inert embedded particles. These embedded particles are uniform in size and placed on the array of a regular lattice. The asymptotic theory of detonation shock dynamics governs the detonation shock propagation in the explosive. Mesoscale hydrodynamic simulations are used to show how the particles are compressed, deformed, and accelerated by the high-speed detonation products flow.

  17. Explosive treatment of Illinois No.6 coal with a mixed solvent of water and cyclohexanol; Mizu-cyclohexanol kongo yozai ni yoru Illinois tan no bakusai shori

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, T.; Takada, H.; Asami, K.; Yano, M. [Osaka City University, Osaka (Japan). Faculty of Engineering


    Coal was treated at high temperature under high pressure in the binary system mixed solvent of water and organic solvent, and the solvent treated coal was liquefied. When the treated coal was treated again by the explosive method in which high temperature and pressure were released immediately, the oil yield was higher than that by the normal method in which high temperature and pressure were reduced gradually to room temperature and atmospheric pressure. In this study, an explosive treatment unit with increased scale of sample amount was newly fabricated. Illinois No.6 coal was treated by the explosive method in a mixed solvent of water and cyclohexanol using this unit. Changes in shape on the surface, specific surface area, and functional groups were analyzed. The explosively treated coal contained more amount of low boiling point components than the normally treated coal. It was suggested that the oil yield of explosively treated coal increased due to the liquefaction of these components during the successive hydrogenation process. For the explosively treated coal, micro pores were fractured by the rapid change in the volume of solvent molecules, and the specific surface area was smaller than that of the normally treated coal. When the treatment temperature was increased from 300{degree}C to 350{degree}C, specific surface areas of both the treated coals increased. 2 refs., 3 figs., 2 tabs.

  18. Air Blasts from Cased and Uncased Explosives

    Energy Technology Data Exchange (ETDEWEB)

    Glenn, L. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)


    The problem of a spherical blast in air is solved using the STUN code. For bare charges, the calculations are shown to be in excellent agreement with previous published results. It is demonstrated that, for an unconfined (uncased) chemical explosive, both range and time to effect scale inversely as the cube root of the yield and directly as the cube root of the ambient air density. It is shown that the peak overpressure decays to roughly 1/10 of ambient pressure in a scaled range of roughly 10 m/kg1/3 at sea level. At a height of 30 km, where the ambient density is a factor of 64 less, the range to the same decay increases to 40 m/kg1/3 . As a direct result of the scaling a single calculation suffices for all charge sizes and altitudes. Although the close-in results are sensitive to the nature of the explosive source and the equation of state of the air, this sensitivity is shown to virtually disappear at scaled ranges > 0.5 m/kg1/3 . For cased explosives the case thickness introduces an additional scale factor. Moreover, when the blast wave arrives at the inner case radius the case begins to expand. Fracture occurs when a critical value of the resulting hoop strain is reached, causing the case to shatter into fragments. A model is proposed to describe the size distribution of the fragments and their subsequent motion via drag interaction with the explosion products and ambient air. It is shown that a significant fraction of the charge energy is initially transmitted to the case fragments in the form of kinetic energy; for example, a 1 kg spherical charge with a 5 mm thick steel case has almost 29% of the total charge energy as initial kinetic energy of case fragments. This percentage increases with increasing case thickness and decreases with increasing charge size. The peak overpressure at a given range is 70-85% for cased explosives as compared with uncased and the peak impulse per unit area is 90-95%. The peak overpressure and

  19. Seismo-acoustic analysis for series of ammunition demolition explosions at Sayarim, Israel (United States)

    Pinsky, V.; Gitterman, Y.; Ben-Horin, Y.; Arrowsmith, S.


    We analyzed detection and location capabilities of a seismo-acoustic network using records of explosion series conducted recently at Sayarim Military Range (SMR), Israel, for demolition of outdated ammunitions. The signals from the explosions have been recorded at local distances by the Israel Seismic Network (ISN), two single infrasound sensors co-located with ISN seismic stations and two infrasound arrays deployed by Israel NDC: 5-element IMA (at Mt. Meron), co-located with IMS seismic array MMAI, and 4-element test temporary array in Northern Negev. All shots (each one with nominal explosives weight ~10-15 tons, detonated simultaneously) were located at the same small area ~0.5x0.5 km, in some cases placed in several grooves, separated by 0.3-0.5 km. Some shots were divided in time by only 20-40 sec, facilitating analysis of the source variability under about constant atmospheric conditions. The following preliminary results have been obtained: 1) the accuracy of seismo-acoustic source location, provided by 5 seismic stations and 2 acoustic receivers using celerity model and wind profile for the day, was within ±1 km of the SMR explosion site; 2) the analysis of acoustic phases recorded at ISN seismic stations at different azimuths showed a clear correlation of the phase peak amplitude with the wind direction; 3) infrasound signals from the explosions were clearly detected at IMA array at 340 km, whereas seismic signals were attenuated below the background noise after 100-150 km; 4) the frequency band occupied by the signal is estimated within 0.2-5 Hz, and the f-k analysis, applied to the infrasound array recordings, provided azimuth of 184° and apparent velocity of 344 m/s, compared to the true azimuth 190° and celerity 277 m/s (the azimuth bias could be explained by the prevailing strong south-western winds ~80 knots observed at a time of the explosion at assumed propagation heights); 5) spectral analysis of infrasound signals provided determination of the


    Directory of Open Access Journals (Sweden)

    G. Dallas


    Full Text Available The purpose of this study was to examine the acute effect of a single bout of whole body vibration (WBV on flexibility and explosive strength of lower limbs in young artistic gymnasts. Thirty-two young competitive gymnasts volunteered to participate in this study, and were allocated to either the vibration group or traditional body weight training according to the vibration protocol. The vibration intervention consisted of a single bout of eccentric and concentric squatting movements on a vibration platform that was turned on (vibration group: VG n=15, whereas the traditional body weight (no vibration group performed the same training protocol with the WBV device turned off (NVG: n= 17. Flexibility (sit and reach test and explosive strength tests [squat jump (SJ, counter movement jump (CMJ, and single leg squat (right leg (RL and left leg (LL] were performed initially (pre-test, immediately after the intervention (post-test 1, and 15 minutes after the end of the intervention programme (post-test 15. Four 2x3 ANOVAs were used to examine the interaction between group (VG vs NVG and time (pre, post 1, and post 15 with respect to examined variables. The results revealed that a significant interaction between group and time was found with respect to SJ (p 0.05. Further, the percentage improvement of the VG was significantly greater in all examined variables compared to the NVG. This study concluded that WBV training improves flexibility and explosive strength of lower limbs in young trained artistic gymnasts and maintains the initial level of performance for at least 15 minutes after the WBV intervention programme.

  1. Surface effects of underground nuclear explosions

    Energy Technology Data Exchange (ETDEWEB)

    Allen, B.M.; Drellack, S.L. Jr.; Townsend, M.J.


    The effects of nuclear explosions have been observed and studied since the first nuclear test (code named Trinity) on July 16, 1945. Since that first detonation, 1,053 nuclear tests have been conducted by the US, most of which were sited underground at the Nevada Test Site (NTS). The effects of underground nuclear explosions (UNEs) on their surroundings have long been the object of much interest and study, especially for containment, engineering, and treaty verification purposes. One aspect of these explosion-induced phenomena is the disruption or alteration of the near-surface environment, also known as surface effects. This report was prepared at the request of the Los Alamos National Laboratory (LANL), to bring together, correlate, and preserve information and techniques used in the recognition and documentation of surface effects of UNEs. This report has several main sections, including pertinent background information (Section 2.0), descriptions of the different types of surface effects (Section 3.0), discussion of their application and limitations (Section 4.0), an extensive bibliography and glossary (Section 6.0 and Appendix A), and procedures used to document geologic surface effects at the NTS (Appendix C). Because a majority of US surface-effects experience is from the NTS, an overview of pertinent NTS-specific information also is provided in Appendix B. It is not within the scope of this report to explore new relationships among test parameters, physiographic setting, and the types or degree of manifestation of surface effects, but rather to compile, summarize, and capture surface-effects observations and interpretations, as well as documentation procedures and the rationale behind them.

  2. Explosive Boiling in Z-pinch Plasmas* (United States)

    de Groot, John S.; Bauer, Bruno S.


    Recently, high resolution x-ray backlighting (radiography), experiments [1] have shown complex small-scale (typical sizes of 2-30 µm) structure of the exploding wire cores of both single-wire and multiwire loads subjected to 2-5 kA per 7.5-25 µm diameter wire for 1µs. The radiographs show features implying that the core has become a foam-like, liquid-vapor mixture. This foam-like state is apparently caused by explosive boiling. The point is that the wires are heated so rapidly that normal boiling (vapor bubbles are formed heterogeneously in the liquid) cannot occur. In explosive boiling, the liquid is superheated to a temperature close to the critical temperature and the phase change occurs explosively in times as short as a few ns. Homogeneous bubble nucleation occurs and the wire makes a very rapid transition from superheated liquid to a mixture of vapor and liquid droplets. This behavior will have very important effects on wire initiation in Z-pinch driven wire arrays and breakdown in MITLs. The ablation of the wire to form the coronal plasma and the remaining core plasma will be quite different for the mixed state. The mixed state is not modeled in the MHD codes that are being used to model wire initiation. We are developing models of the mixed state to include in the MHD codes. We are also developing experiments to improve the understanding of this curious state of matter. 1. Pikuz, S. A., Shelkovenko, T. A., Sinars, D. B., Greenly, J. B., Dimant, Y. S., and Hammer, D. A., Phys. Rev. Letters 83, 4313-4316 (1999). *Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the United States Department of Energy Under Contract DE-AC04-94AL85000.

  3. Storage standards for industrial explosives, May 2001

    Energy Technology Data Exchange (ETDEWEB)



    The storage standards for industrial explosives comprise the following 3 parts: (1) magazine storage standards, (2) storage operation principles, and (3) ruling and policy decisions for magazines built before May 31, 2001. There are many refinements and improvements in these revised storage standards which were first published in 1972. They come into force on May 31, 2001 and update and supersede the Revised 1982 Magazine Standards for Blasting Explosives and Detonators. The Explosives and Regulatory Division (ERD) of Natural Resources Canada worked with the Royal Canadian Mounted Police (RCMP) to develop and adopt a redesign of the walk-in magazine door to ensure greater security. The laminated door is mandatory for all new walk-in-type magazines immediately. For existing magazine installations, it will be phased in over a period of 5 to 10 years with most emphasis on those areas with a high risk of break-ins. ERD has also moved from heavy duty-locks to high-security locking hardware and is emphasizing better key control for magazines with no grandfathering on locking hardware. The wall thicknesses for the new Type 4 magazine standards have been upgraded from 5 to 7.6 cm for gravel and 15 cm for sand. Types 2, 3, 5, and 7 magazines will no longer be allowed under this new standard. Type 9 magazines will also be phased out over the next 5 years and will be replaced by an upgraded design similar to Type 4 magazine. Type 11 magazine standards have also been revised to use the ISO seacan container which has a newer door concept with ballistic materials in the walls. With these revised standards, only approved welding facilities across Canada will be issued design details of magazine doors. Each magazine will have a unique code of numbers corresponding to a tag and noted on the licence. Each of these storage standards has been upgraded to reflect higher security. tabs., figs.

  4. Thermal Environment inside a Tunnel after Thermobaric Explosion

    Directory of Open Access Journals (Sweden)

    Fei Chen


    Full Text Available The outstanding thermal damage effect of thermobaric explosive (TBX is enhanced in closed or semiclosed spaces, which may pose a serious threat to the security of people sheltered in tunnels or other protective engineering. In order to investigate the thermal environment inside a tunnel after thermobaric explosion, we developed a damage evaluation method for the thermal radiation of explosion fireballs in tunnels; secondly, the air temperature distribution inside a tunnel shortly after explosion was theoretically analyzed; finally, the dynamic thermal environment after the explosion and the influences of TBXs mass and initial ground temperature on it in cases of open and blocked tunnels were numerically simulated with the FLUENT software. The results show that the fireball thermal radiation damage occurs mainly in the vicinity of the explosion source. The air temperature inside a tunnel shortly after the explosion decreases continuously with increasing distance from the explosion source and finally reaches the initial air temperature. The decay rate of air temperature inside a tunnel is slower in the blocked case, which increases the probability of causing a secondary fire disaster. The increase of explosive mass and the initial ground temperature favor the high-temperature performance of TBX, especially for the blocked tunnel.

  5. Remote Machining and Evaluation of Explosively Filled Munitions (United States)

    Federal Laboratory Consortium — This facility is used for remote machining of explosively loaded ammunition. Munition sizes from small arms through 8-inch artillery can be accommodated. Sectioning,...

  6. Large-volume sampling and preconcentration for trace explosives detection.

    Energy Technology Data Exchange (ETDEWEB)

    Linker, Kevin Lane


    A trace explosives detection system typically contains three subsystems: sample collection, preconcentration, and detection. Sample collection of trace explosives (vapor and particulate) through large volumes of airflow helps reduce sampling time while increasing the amount of dilute sample collected. Preconcentration of the collected sample before introduction into the detector improves the sensitivity of the detector because of the increase in sample concentration. By combining large-volume sample collection and preconcentration, an improvement in the detection of explosives is possible. Large-volume sampling and preconcentration is presented using a systems level approach. In addition, the engineering of large-volume sampling and preconcentration for the trace detection of explosives is explained.

  7. Vapor explosion studies for nuclear and non-nuclear industries

    Energy Technology Data Exchange (ETDEWEB)

    Taleyarkhan, Rusi P. [Arden L. Bement, Jr. Professor Nuclear Engineering, School of Nuclear Engineering, 1290 Nuclear Engineering Building, Room 108C, Purdue University, West Lafayette, IN 47905 (United States)]. E-mail:


    Energetic melt-water explosions are a well-established contributor to risk for nuclear reactors, and even more so for the metal casting industry. In-depth studies were undertaken in an industry-national laboratory collaborative effort to understand the root causes of explosion triggering and to evaluate methods for prevention. The steam explosion triggering studies (SETS) facility was devised and implemented for deriving key insights into explosion prevention. Data obtained indicated that onset of base surface-entrapment induced explosive boiling-caused trigger shocks is a result of complex combination of surface wettability, type of coating (organic versus inorganic), degree of coating wearoff, existence of bypass pathways for pressure relief, charring and non-condensable gas (NCG) release potential. Of these parameters NCGs were found to play a preeminent role on explosion prevention by stabilizing the melt-water steam interface and acting as a shock absorber. The role of NCGs was experimentally confirmed using SETS for their effect on stable film boiling using a downward facing heated body through which gases were injected. The presence of NCGs in the steam film layer caused a significant delay in the transitioning of film-to-nucleate boiling. The role of NCGs on explosion prevention was thereafter demonstrated more directly by introducing molten metal drops into water pools with and without NCG bubbling. Whereas spontaneous and energetic explosions took place without NCG injection, only benign quenching occurred in the presence of NCGs. Gravimetric analyses of organic coatings which are known to prevent explosion onset were also found to release significant NCGs during thermal attack by melt in the presence of water. These findings offer a novel, simple, cost-effective technique for deriving fundamental insights into melt-water explosions as well as for explosion prevention under most conditions of interest to metal casting, and possibly for nuclear reactor

  8. Explosion of a road tanker containing liquefied natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Planas-Cuchi, E.; Casal, J. [Universitat Politecnica de Catalunya, Catalonia (Spain). CERTEC; Gasulla, N.; Ventosa, A. [Autonomous Government of Catalonia (Spain). General Directorate for Emergencies and Civl Security


    The explosion of a road tanker transporting LNG (one person killed, two injured) is studied. The analysis shows that the explosion, which followed a two-step mode as for the failure of the vessel, could have been a boiling liquid expanding vapor explosion (BLEVE). The overpressure and thermal radiation have been estimated and related to the effects observed. Only a relatively small part of the energy released in the explosion was manifested in the pressure wave. The large fragments (the three pieces into which the tank was broken) and the truck motor were ejected at various distances along the tank's main axis. (author)

  9. Nonisotropic radiation of the 2013 North Korean nuclear explosion (United States)

    Vavryčuk, Václav; Kim, So Gu


    On 12 February 2013, North Korea conducted an underground nuclear test in the northeastern mountainous part of the country. The explosion reached magnitude mb = 5.1 being recorded at most of seismic stations around the world and becoming one of the best ever recorded nuclear explosions in history. Similarly, as other nuclear explosions buried in Nevada, Kazakhstan, or China, the 2013 North Korean explosion is characterized by a significant nonisotropic radiation. This radiation is manifested by distinct SH and Love waves in the wave field and is inconsistent with the model of a spherically symmetric source. We show that the Love waves are not generated by a tectonic earthquake triggered on a nearby fault structures but produced by asymmetry of the explosive source caused by presence of deviatoric stress in the surrounding rock. The retrieved moment tensor of the 2013 explosion is characterized by the isotropic component of 57 ± 5%, the double-couple component of 17 ± 9%, and the compensated linear vector dipole component of 24 ± 7%. The P, T, and N axes of the moment tensor are consistent with the principal axes of the regional tectonic stress in the Korean Peninsula. A comparison of waveforms and particle motions of the 2013 explosion and the previous North Korean nuclear explosion buried in 2009 indicates that the 2013 explosion was slightly more nonisotropic.

  10. Hyperspectral requirements for detection of trace explosives agents (United States)

    Schau, Harvey C.; Jennette, Bryan D.


    The ability to remotely detect explosive devices and explosive materials has generated considerable interest over the last several years. The study of remote sensing of explosives date back many decades but recent world events have forced the technology to respond to changing events and bring new technologies to the field in shorter development times than previously thought possible. Several applications have proven both desirable and illusive to date. Most notable is the desire to sense explosives within containers, sealed or otherwise. This requires a sensing device to penetrate the walls of the container, a difficult task when the container is steel or thick cement. Another is the desire to detect explosive vapors which escape from a container into the ambient air. This has been made difficult because explosives are generally formulated to have extremely low vapor pressure. (This has made many gas detection technique not strong candidates for explosive vapor detection due to the low vapor pressure of explosive materials [1].) Because of the many difficulties in a general explosive remote detection, we have attempted to bound the problem into a series of achievable steps with the first step a simple remote detection of TNT-bearing compounds. Prior to discussing our technology, we will first discuss our choice for attacking the problem in this manner.

  11. Coal-preparation baghouse protects against explosion damage

    Energy Technology Data Exchange (ETDEWEB)


    Improvements in baghouse containment technology are reducing the risks when air and coal dust mixtures ignite and cause secondary explosions that were formerly vented. The cement industry was quick to adopt the new technology that resembles a circular pressure vessel able to withstand a 50-psi internal pressure and contain secondary explosions. Steps to minimize primary explosions include new standards for baghouse design and construction to eliminate components that cause sparks, electrical grounding, continuous dust removal, high air-to-cloth ratios, and pulse jet cleaning. Other considerations involving baghouse location, maintenance access, fire suppression, and rotary valve sizing can also reduce explosion risks. (DCK)

  12. 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)


    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.

  13. Ballistic Evaluation of Aircraft Explosion Suppression Materials (United States)


    Inside tihe tank, the use of a fan as in TWS No. I was prwL\\luded. The system devised is depicted in Figure No. 5. lt is composed of two electric fans daLa acquisition and control system. This system was composed of an HP 2100 mini-computer with associated analog-to- digital converters, relay...panel damage. h’lherefore, for all of the explosion suppression materiali tested, there did not appear to he any marked difference in exit panel

  14. Luck Reveals Stellar Explosion's First Moments (United States)


    Through a stroke of luck, astronomers have witnessed the first violent moments of a stellar explosion known as a supernova. Astronomers have seen thousands of these stellar explosions, but all previous supernovae were discovered days after the event had begun. This is the first time scientists have been able to study a supernova from its very beginning. Seeing one just moments after the event began is a major breakthrough that points the way to unraveling longstanding mysteries about how such explosions really work. Galaxy Before Supernova Explosion NASA's Swift satellite took these images of SN 2007uy in galaxy NGC 2770 before SN 2008D exploded. An X-ray image is on the left; image at right is in visible light. CREDIT: NASA/Swift Science Team/Stefan Immler. Large Image With Labels Large Image Without Labels Galaxy After Supernova Explosion On January 9, 2008, Swift caught a bright X-ray burst from an exploding star. A few days later, SN 2008D appeared in visible light. CREDIT: NASA/Swift Science Team/Stefan Immler. Large Image With Labels Large Image Without Labels "For years, we have dreamed of seeing a star just as it was exploding," said team leader Alicia Soderberg, a Hubble and Carnegie-Princeton Fellow at Princeton University. "This newly-born supernova is going to be the Rosetta Stone of supernova studies for years to come." Theorists had predicted for four decades that a bright burst of X-rays should be produced as the shock wave from a supernova blasts out of the star and through dense material surrounding the star. However, in order to see this burst, scientists faced the nearly-impossible challenge of knowing in advance where to point their telescopes to catch a supernova in the act of exploding. On January 9, luck intervened. Soderberg and her colleagues were making a scheduled observation of the galaxy NGC 2770, 88 million light-years from Earth, using the X-ray telescope on NASA's Swift satellite. During that observation, a bright burst of X

  15. Projection image enhancement for explosive detection systems (United States)

    Yildiz, Yesna O.; Abraham, Douglas Q.; Agaian, Sos; Panetta, Karen


    Automated Explosive Detection Systems (EDS) utilizing Computed Tomography (CT) generate a series of 2-D projections from a series of X-ray scans OF luggage under inspection. 3-D volumetric images can also be generated from the collected data set. Extensive data manipulation of the 2-D and 3-D image sets for detecting the presence of explosives is done automatically by EDS. The results are then forwarded to human screeners for final review. The final determination as to whether the luggage contains an explosive and needs to be searched manually is performed by trained TSA (Transportation Security Administration) screeners following an approved TSA protocol. The TSA protocol has the screeners visually inspect the resulting images and the renderings from the EDS to determine if the luggage is suspicious and consequently should be searched manually. Enhancing those projection images delivers a higher quality screening, reduces screening time and also reduces the amount of luggage that needs to be manually searched otherwise. This paper presents a novel edge detection algorithm that is geared towards, though not exclusive to, automated explosive detection systems. The goal of these enhancements is to provide a higher quality screening process while reducing the overall screening time and luggage search rates. Accurately determining the location of edge pixels within 2-D signals, often the first step in segmentation and recognition systems indicates the boundary between overlapping objects in a luggage. Most of the edge detection algorithms such as Canny, Prewitt, Roberts, Sobel, and Laplacian methods are based on the first and second derivatives/difference operators. These operators detect the discontinuities in the differences of pixels. These approaches are sensitive to the presence of noise and could produce false edges in noisy images. Including large scale filters, may avoid errors generated by noise, but often simultaneously eliminating the finer edge details as

  16. Reaction Studies for Explosive Nuclear Astrophysics (United States)

    Woods, Philip J.

    The paper describes experimental approaches to measuring key nuclear astrophysical reactions involving radioactive isotopes. Specifically the paper considers the utilisation of (d, n) and (d, p) transfer reactions to probe the strengths of key resonances in the hydrogen burning/proton capture reactions 30P(p, γ) and 26Al(p, γ). The use of a radioactive target and silicon strip detector set-ups to study the key 26Al(n, p) and (n, α) destruction reactions relevant to explosive burning conditions in core collapse supernovae is also reported.

  17. Optical chemosensors and reagents to detect explosives


    Salinas Soler, Yolanda; Martínez Mañez, Ramón; Marcos Martínez, María Dolores; Sancenón Galarza, Félix; Costero Nieto, Ana Maria; Parra Alvarez, Margarita; Gil Grau, Salvador


    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. Spanish Government (project MAT2009-14564-C04) Generalitat Valencia (project PROMETEO/2009/016) Spanish Ministry of Science and Innovation Salinas Soler, Y.; Martínez Mañez, R.; Marcos Martínez, MD.; Sancenón Galarza, F.; Costero Nieto, AM.; Parra Alvarez, M.; Gil Grau, S...

  18. Crossing the Boundaries in Planetary Atmospheres - From Earth to Exoplanets (United States)

    Simon-Miller, Amy A.; Genio, Anthony Del


    The past decade has been an especially exciting time to study atmospheres, with a renaissance in fundamental studies of Earths general circulation and hydrological cycle, stimulated by questions about past climates and the urgency of projecting the future impacts of humankinds activities. Long-term spacecraft and Earth-based observation of solar system planets have now reinvigorated the study of comparative planetary climatology. The explosion in discoveries of planets outside our solar system has made atmospheric science integral to understanding the diversity of our solar system and the potential habitability of planets outside it. Thus, the AGU Chapman Conference Crossing the Boundaries in Planetary Atmospheres From Earth to Exoplanets, held in Annapolis, MD from June 24-27, 2013 gathered Earth, solar system, and exoplanet scientists to share experiences, insights, and challenges from their individual disciplines, and discuss areas in which thinking broadly might enhance our fundamental understanding of how atmospheres work.

  19. Solid state gas sensors for detection of explosives and explosive precursors (United States)

    Chu, Yun

    The increased number of terrorist attacks using improvised explosive devices (IEDs) over the past few years has made the trace detection of explosives a priority for the Department of Homeland Security. Considerable advances in early detection of trace explosives employing spectroscopic detection systems and other sensing devices have been made and have demonstrated outstanding performance. However, modern IEDs are not easily detectable by conventional methods and terrorists have adapted to avoid using metallic or nitro groups in the manufacturing of IEDs. Instead, more powerful but smaller compounds, such as TATP are being more frequently used. In addition, conventional detection techniques usually require large capital investment, labor costs and energy input and are incapable of real-time identification, limiting their application. Thus, a low cost detection system which is capable of continuous online monitoring in a passive mode is needed for explosive detection. In this dissertation, a thermodynamic based thin film gas sensor which can reliably detect various explosive compounds was developed and demonstrated. The principle of the sensors is based on measuring the heat effect associated with the catalytic decomposition of explosive compounds present in the vapor phase. The decomposition mechanism is complicated and not well known, but it can be affected by many parameters including catalyst, reaction temperature and humidity. Explosives that have relatively high vapor pressure and readily sublime at room temperature, like TATP and 2, 6-DNT, are ideal candidate for vapor phase detection using the thermodynamic gas sensor. ZnO, W2O 3, V2O5 and SnO2 were employed as catalysts. This sensor exhibited promising sensitivity results for TATP, but poor selectivity among peroxide based compounds. In order to improve the sensitivity and selectivity of the thermodynamic sensor, a Pd:SnO2 nanocomposite was fabricated and tested as part of this dissertation. A

  20. Contribution of Neutron Beta Decay to Radiation Belt Pumping from High Altitude Nuclear Explosion

    Energy Technology Data Exchange (ETDEWEB)

    Marrs, R


    In 1962, several satellites were lost following high altitude nuclear tests by the United States and the Soviet Union. These satellite failures were caused by energetic electrons injected into the earth's radiation belts from the beta decay of bomb produced fission fragments and neutrons. It has been 40 years since the last high altitude nuclear test; there are now many more satellites in orbit, and it is important to understand their vulnerability to radiation belt pumping from nuclear explosions at high altitude or in space. This report presents the results of a calculation of the contribution of neutron beta decay to artificial belt pumping. For most high altitude nuclear explosions, neutrons are expected to make a smaller contribution than fission products to the total trapped electron inventory, and their contribution is usually neglected. However, the neutron contribution may dominate in cases where the fission product contribution is suppressed due to the altitude or geomagnetic latitude of the nuclear explosion, and for regions of the radiation belts with field lines far from the detonation point. In any case, an accurate model of belt pumping from high altitude nuclear explosions, and a self-consistent explanation of the 1962 data, require inclusion of the neutron contribution. One recent analysis of satellite measurements of electron flux from the 1962 tests found that a better fit to the data is obtained if the neutron contribution to the trapped electron inventory was larger than that of the fission products [l]. Belt pumping from high altitude nuclear explosions is a complicated process. Fission fragments are dispersed as part of the ionized bomb debris, which is constrained and guided by the earth's magnetic field. Those fission products that beta decay before being lost to the earth's atmosphere can contribute trapped energetic electrons to the earth's radiation belts. There has been a large effort to develop computer models for

  1. Explosive formation of coherent particle jets (United States)

    Frost, David; Ruel, Jean-Frederic; Zarei, Zouya; Goroshin, Sam; Gregoire, Yann; Zhang, Fan; Milne, Alec; Longbottom, Aaron


    A high-speed jet of solid particles may be formed by detonating an explosive layer lining the outside of a conically-shaped volume of particles. Experiments have been carried out to determine the velocity history and the coherency of a particle jet formed using this shaped-charge arrangement. Important parameters include the cone angle, the ratio of the masses of the explosive and particles, and the particle size and density. Dense particles (e.g., iron) form thin, stable, coherent jets, whereas lighter particles (e.g., glass or Al) lead to more diffuse jets. The jet velocities observed experimentally were close to the predictions from a Gurney velocity formulation for conical geometry. The effects of cone angle and particle density on the jet formation and development were explored with calculations using a multimaterial hydrocode. The simulations indicate that the converging shock and Mach disk within the particle bed have a strong influence on the uniformity of the particle density field. With iron particles, the particle volume remains coherent whereas for glass particles, during the particle acceleration phase, the shock interactions within the particle bed cause the particles to be concentrated in a thin shell surrounding a low density region.

  2. Biotreatment of explosive-contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Shen, C. F.; Guiot, S. R.; Manuel, M. F.; Havari, J. [National Research Council of Canada, Biotechnology Research Institute, Montreal, PQ (Canada)


    A research project was undertaken to develop a process for the remediation of soils which have been contaminated by 2,4,6 trinitrotoluene (TNT), and/or by hexahydro-1.3,5-trinitro-1,3,5-triazine (RDX), two of the most widely used military explosives. In this context, municipal activated sludge and anaerobic sludge were evaluated for their TNT and RDX degrading ability. Results showed that TNT was easily degraded in the bioslurry reactors. Complete removal was achieved in less than two weeks of reactor operation. Removal efficiency was further increased by the addition of anaerobic sludge. RDX degradation was poor under most operating conditions. Only 25 per cent to 40 per cent of RDX was degraded after five weeks of operation, however, in one of the reactors which received an injection of 20 per cent anaerobic sludge, and was operated under anaerobic conditions, RDX removal was 100 per cent after 37 days. These results support the conclusion that municipal anaerobic sludge and activated sludge are rich sources of TNT and RDX degrading organisms, therefore, bioslurry reactors may be a cost-effective approach to on-site bioremediation of explosive-contaminated soils.

  3. The Development of Explosive Metalworking in Poland

    Directory of Open Access Journals (Sweden)

    Babul W.


    Full Text Available The author coordinated the research in Poland by the collaboration with civil and military scientific and research centres. In result they elaborated detonation process of spraying coats designed and constructed stands equipped with detonative devices, they also elaborated the techniques of basic coating parameter measurement and built devices for commercial and scientific services. In the research the author's achievements within the range of explosive welding have been used. The experience of the scientific teams was very effective. It was observed that many phenomena that take place in the processes of detonative layer coating and explosive welding are the same. In order to obtain a required connection the plastic strain of the connected material surfaces has to be achieved and cumulative flows have to be formed. There are a similar range of the connecting process conditions and the mechanisms of plastic strain. The highest connection strength is obtained when an intermediate zone is formed. The zone has to be composed of the two connected materials. The intermediate layer is formed as a result of mechanical alloying of the materials due to large plastic strain. The plastic strain leads to forming meta-stable phases that have properties of pseudo solid solution, chemical compounds, intermetallic phases and fragmentation corresponding to nanomaterials and amorphous states.

  4. Surface detonation in type Ia supernova explosions? (United States)

    Röpke, F. K.; Woosley, S. E.


    We explore the evolution of thermonuclear supernova explosions when the progenitor white dwarf star ignites asymmetrically off-center. Several numerical simulations are carried out in two and three dimensions to test the consequences of different initial flame configurations such as spherical bubbles displaced from the center, more complex deformed configurations, and teardrop-shaped ignitions. The burning bubbles float towards the surface while releasing energy due to the nuclear reactions. If the energy release is too small to gravitationally unbind the star, the ash sweeps around it, once the burning bubble approaches the surface. Collisions in the fuel on the opposite side increase its temperature and density and may - in some cases - initiate a detonation wave which will then propagate inward burning the core of the star and leading to a strong explosion. However, for initial setups in two dimensions that seem realistic from pre-ignition evolution, as well as for all three-dimensional simulations the collimation of the surface material is found to be too weak to trigger a detonation.

  5. FAA bulk technology overview for explosives detection (United States)

    Novakoff, Alan K.


    The Federal Aviation Administration (FAA) is the leading federal agency responsible for encouraging and fostering the development of a safe, secure, and efficient national airspace system (NAS). Our goal is to establish an operating environment that ensures a threat-free system to preclude acts of terrorism and fatalities. As part of the process to meet this goal, our research and development activities continually search for technologies to ensure aviation security. Recent acts of terrorism against the aviation community have demonstrated an increasing level of sophistication in the design and deployment of explosive devices. In order to prevent the introduction of explosives onto an aircraft they must be detected prior to passenger and baggage loading. The Bulk Detection program is one method of developing a number of technologies that 'see' into and 'alarm' on suspect baggage. These detection devices must be capable of providing this serve with a confidence commensurate with the state-of-the- art available today. This program utilizes the expertise of government agencies, universities and industries working toward constructing their plans and executing their designs to produce the best available equipment.

  6. Contamination with explosives in analytical laboratory procedure. (United States)

    Pawłowski, Wojciech; Matyjasek, Łukasz; Cieślak, Katarzyna; Karpińska, Monika


    The philosophy underlying the procedure with the trace from the moment of the securing of the evidence up to its ultimate inspection is of significance for the result achieved. Hands of the people who conduct investigative action or of the experts involved in examinations contaminated with explosives may adversely affect results of the analyses. The contamination effect is one of the most dangerous consequences of non-observance of the strict rules in handling the traces secured on the crime scene. The aim of this research work was to examine whether at all, and if so, with what an ease and at which stage of the analytical procedure there occurs a likely contamination of the evidence material with explosives such as TNT, RDX, PETN, NG. The analytical procedure employed consisted of the sampling stage, extraction from gauze swab, transfer of the extract and execution of an instrumental analysis based on gas chromatography with electron capture detector (ECD). The most significant contamination effect was observed during the analytical procedure for TNT, followed by a similar, yet less pronounced, for RDX and PETN. Contaminating the research material with nitroglycerin, known to be liquid under normal conditions, proved unsuccessful. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. The Interaction of Two Underwater Explosion Bubbles (United States)

    Milligan, Charles; Duncan, James


    The interaction between two growing and collapsing underwater explosion bubbles is studied experimentally and numerically. In the experiments, the bubbles are generated by detonating small Lead Azide explosive charges submerged in a transparent water tank, and the resulting interactions are photographed using a high-speed camera. The parametric studies include simultaneous detonation of two charges of different sizes, and detonation of identically sized charges at staggered times. When the time delay between detonations is significant, the collapsing first bubble forms a jet directed away from the expanding second bubble and then re-expands nonspherically. During the re-expansion of the first bubble, a micro-jet forms in the second bubble. Eventually this micro-jet pierces the side of the second bubble farthest from the first and vortex rings are formed. Numerical simulations of the interaction phenomena are achieved using a boundary element method. By partitioning the system into computational sub-domains it is possible to replicate many relevant physical details including jet formation, fluid-fluid impact, and bubble re-expansion after complete jet penetration. The numerical results are in qualitative agreement with the experimental findings.

  8. Jetting formation of the explosively loaded powders (United States)

    Xue, Kun; Yu, Qiqi


    The formation of jet-like structures is widely reported in the explosive dispersal of powders surrounding high explosive charges. The jetting of powder beds initiates upon the shock wave reaches the outer edge of the charge. Opposed to the interface instability theory, a hollow sphere based bulk fragmentation model is established to account for the jetting of powders. A two-phase process, namely the nucleation and free expansion of hollow spheres, corresponds to the unloading process of the powder compact caused by the rarefaction waves which governs the fragmentation of the powders. The separation between adjacent hollow spheres dictates the size of the particle clusters, which would evolve into particle jets in later times. The predicted breakup time and the size of particle jets agree well with the experimental results. The increased moisture content in powders results in an increased number of particle jets. This moisture effect can be understood in light of the varied energy distribution due to the incompressibility of the interstitial liquids trapped inside the inter-grain pores. The portion of shock energy which is not consumed in the shock compaction of the wet powders would be dissipated through the viscous shear flows during the unloading of the wet powder compact. The excessive viscous energy requires to activate more localized shear flows, accordingly leading to an increased number of particle jets.

  9. Robustness Assessment of Building Structures under Explosion

    Directory of Open Access Journals (Sweden)

    Mark Waggoner


    Full Text Available Over the past decade, much research has focused on the behaviour of structures following the failure of a key structural component. Particular attention has been given to sudden column loss, though questions remain as to whether this event-independent scenario is relevant to actual extreme events such as explosion. Few studies have been conducted to assess the performance of floor slabs above a failed column, and the computational tools used have not been validated against experimental results. The research program presented in this paper investigates the adequacy of sudden column loss as an idealisation of local damage caused by realistic explosion events, and extends prior work by combining the development of accurate computational models with large-scale testing of a typical floor system in a prototypical steel-framed structure. The floor system consists of corrugated decking topped by a lightly reinforced concrete slab that is connected to the floor beams through shear studs. The design is consistent with typical building practices in the US. The first test has been completed, and subsequent tests are currently being planned. This paper addresses the importance of robustness design for localized damage and includes a detailed description regarding how the research program advances the current state of knowledge for assessing robustness of compositely constructed steel-framed buildings.

  10. SANFO: The missing link in explosives technology

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, R.J. [Johnson Hi-Tech Australia Pty Ltd, Queensland (Australia)


    The development of SANFO has provided the mining industry with a low cost high gas volume, variable density, blasting agent which can be blended on site in a simple agitator mixing and charging system by mine site employees. During the last decade most major explosives manufacturers have been promoting high density, high shock energy blasting agents. To offset the cost of these products they have relied on expanded borehole patterns. It has since been discovered that lower VOD products are more effective in most overburden geologies due to the longer explosion pressure period and lower shock energy. These characteristics also reduce energy loss consumed in pulverization around the perimeter of borehole. The major advantages of SANFO compared with normal ANFO or heavy ANFO are as listed. Due to problems associated with bulling when blasting soft geologies at BHP`s Riverside Mine in Central Queensland, Australia, the company was invited to develop a low density blasting agent which could be blended as required on the mine site. This paper describes the problems associated with blasting softer geologies and the use of sawdust as a cost-effective bulking agent.

  11. Analysis of Explosives by GC-UV. (United States)

    Andrasko, Jan; Lagesson-Andrasko, Ludmila; Dahlén, Johan; Jonsson, Bengt-Harald


    A mixture of explosives was analyzed by gas chromatography (GC) linked to ultraviolet (UV) spectrophotometry that enabled detection in the range of 178-330 nm. The gas-phase UV spectra of 2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene (DNT), ethylene glycol dinitrate (EGDN), glycerine trinitrate (NG, nitroglycerine), triacetone triperoxide (TATP), and pentaerythritol tetranitrate (PETN) were successfully recorded. The most interesting aspect of the current application is that it enabled simultaneous detection of both the target analyte and its decomposition products. At suitable elevated temperatures of the transfer line between the GC instrument and the UV detector, a partial decomposition was accomplished. Detection was made in real time and resulted in overlaid spectra of the mother compound and its decomposition product. Hence, the presented approach added another level to the qualitative identification of the explosives in comparison with traditional methods that relies only on the detection of the target analyte. As expected, the decomposition product of EGDN, NG, and PETN was NO, while TATP degraded to acetone. DNT and TNT did not exhibit any decomposition at the temperatures used. © 2017 American Academy of Forensic Sciences.

  12. Hydrogen-poor superluminous stellar explosions. (United States)

    Quimby, R M; Kulkarni, S R; Kasliwal, M M; Gal-Yam, A; Arcavi, I; Sullivan, M; Nugent, P; Thomas, R; Howell, D A; Nakar, E; Bildsten, L; Theissen, C; Law, N M; Dekany, R; Rahmer, G; Hale, D; Smith, R; Ofek, E O; Zolkower, J; Velur, V; Walters, R; Henning, J; Bui, K; McKenna, D; Poznanski, D; Cenko, S B; Levitan, D


    Supernovae are stellar explosions driven by gravitational or thermonuclear energy that is observed as electromagnetic radiation emitted over weeks or more. In all known supernovae, this radiation comes from internal energy deposited in the outflowing ejecta by one or more of the following processes: radioactive decay of freshly synthesized elements (typically (56)Ni), the explosion shock in the envelope of a supergiant star, and interaction between the debris and slowly moving, hydrogen-rich circumstellar material. Here we report observations of a class of luminous supernovae whose properties cannot be explained by any of these processes. The class includes four new supernovae that we have discovered and two previously unexplained events (SN 2005ap and SCP 06F6) that we can now identify as members of the same class. These supernovae are all about ten times brighter than most type Ia supernova, do not show any trace of hydrogen, emit significant ultraviolet flux for extended periods of time and have late-time decay rates that are inconsistent with radioactivity. Our data require that the observed radiation be emitted by hydrogen-free material distributed over a large radius (∼10(15) centimetres) and expanding at high speeds (>10(4) kilometres per second). These long-lived, ultraviolet-luminous events can be observed out to redshifts z > 4.

  13. Atmosphere-Ionosphere Coupling via Atmospheric Waves (United States)

    Koucka Knizova, Petra; Lastovicka, Jan


    The Earth atmosphere and ionosphere is complicated and highly variable system which displays oscillations on wide range scales. The most important factor influencing the ionosphere is certainly the solar and geomagnetic activity. However, the processes even in distant regions in the neutral atmosphere cannot be simply neglected. This contribution reviews aspects of ionospheric variability originating in the lower laying atmosphere. It focuses especially on the generation and propagation of the atmospheric waves from their source region up to the heights of the ionosphere. We will show the role of infrasound, gravity waves, tides and planetary waves in the atmosphere-ionosphere coupling. Particularly gravity waves are of high importance for the ionosphere. Recent theoretical and experimental results will briefly be reviewed.

  14. 40 CFR 457.10 - Applicability; description of the commercial manufacture of explosives subcategory. (United States)


    ... commercial manufacture of explosives subcategory. 457.10 Section 457.10 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS EXPLOSIVES MANUFACTURING POINT SOURCE CATEGORY Manufacture of Explosives Subcategory § 457.10 Applicability; description of the...

  15. Aluminum Micro Balloons as Improved Fuel for Warhead Explosives (United States)


    Improved Fuel for Warhead Explosives Distribution Statement A. Approved for public release; distribution is unlimited. January 2018 HDTRA1...A. Shidlovskij, "Explosive mixtures of water and methanol with magnesium and aluminum," J. Prikl. Khimii, vol. 19, pp. 371-378, 1946. 3. Oren E

  16. Explosion of a collapsing Bose-Einstein condensate

    NARCIS (Netherlands)

    Duine, R.A.; Stoof, H.T.C.


    We show that elastic collisions between atoms in a Bose-Einstein condensate with attractive interactions can lead to an explosion that ejects a large fraction of the collapsing condensate. We study variationally the dynamics of this explosion and find excellent agreement with recent experiments on

  17. Explosion of a Collapsing Bose-Einstein Condensate

    NARCIS (Netherlands)

    Duine, R.A.; Stoof, H.T.C.


    we show that elastic collisions between atoms in an Bose-Einstein condensate with attractive interactions lead to an explosion that ejects a large fraction of the collapsing condensate. We study variationally the dynamics of thes explosion and find excellent agreement with recent experiments on

  18. 40 CFR 265.382 - Open burning; waste explosives. (United States)


    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Open burning; waste explosives. 265.382 Section 265.382 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES... explosives or propellants Minimum distance from open burning or detonation to the property of others 0 to 100...

  19. 30 CFR 56.6205 - Conveying explosives by hand. (United States)


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Conveying explosives by hand. 56.6205 Section 56.6205 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Transportation § 56.6205 Conveying explosives by hand. Closed, nonconductive containers shall be used to carry...

  20. 30 CFR 57.6205 - Conveying explosives by hand. (United States)


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Conveying explosives by hand. 57.6205 Section 57.6205 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Transportation-Surface and Underground § 57.6205 Conveying explosives by hand. Closed, nonconductive containers...

  1. Ultraviolet Resonance Raman Enhancements in the Detection of Explosives (United States)


    2. Peroxide-based Explosives In 2001, the U.S. encountered homemade peroxide-based explosives when Richard Reid attempted to detonate PETN...R. P. Feynman , R. B. Leighton, R. B and M. L. Sands, The Feynman Lectures on Physics. Reading, Mass: Addison-Wesley Pub, 1963. [40] S. D

  2. 36 CFR 331.5 - Explosives and fireworks. (United States)


    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Explosives and fireworks. 331... CONSERVATION AREA, KENTUCKY AND INDIANA § 331.5 Explosives and fireworks. Unless otherwise authorized in writing by the District Engineer. (a) The possession or use of fireworks is prohibited. (b) The possession...

  3. 43 CFR 423.30 - Weapons, firearms, explosives, and fireworks. (United States)


    ... fireworks. 423.30 Section 423.30 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF... WATERBODIES Rules of Conduct § 423.30 Weapons, firearms, explosives, and fireworks. (a) You may possess... with applicable Federal, State, and local law. (c) You must not use or possess explosives, or fireworks...



    Niculae MARIN; Victor GHIZDAVU


    The explosive forming represents a technological alternative for obtaining small-lot parts,with inexpensive and efficient manufacturing preparation. The explosive forming processing methodspresent a series of important advantages, being recommended for the wide-scale application in theaerospace industry. The economic benefit varies from case to case, independent from the part type,manufacturing series and user.


    Directory of Open Access Journals (Sweden)

    Niculae MARIN


    Full Text Available The explosive forming represents a technological alternative for obtaining small-lot parts,with inexpensive and efficient manufacturing preparation. The explosive forming processing methodspresent a series of important advantages, being recommended for the wide-scale application in theaerospace industry. The economic benefit varies from case to case, independent from the part type,manufacturing series and user.

  6. Design optimization of Cassegrain telescope for remote explosive trace detection (United States)

    Bhavsar, Kaushalkumar; Eseller, K. E.; Prabhu, Radhakrishna


    The past three years have seen a global increase in explosive-based terror attacks. The widespread use of improvised explosives and anti-personnel landmines have caused thousands of civilian casualties across the world. Current scenario of globalized civilization threat from terror drives the need to improve the performance and capabilities of standoff explosive trace detection devices to be able to anticipate the threat from a safe distance to prevent explosions and save human lives. In recent years, laser-induced breakdown spectroscopy (LIBS) is an emerging approach for material or elemental investigations. All the principle elements on the surface are detectable in a single measurement using LIBS and hence, a standoff LIBS based method has been used to remotely detect explosive traces from several to tens of metres distance. The most important component of LIBS based standoff explosive trace detection system is the telescope which enables remote identification of chemical constituents of the explosives. However, in a compact LIBS system where Cassegrain telescope serves the purpose of laser beam delivery and light collection, need a design optimization of the telescope system. This paper reports design optimization of a Cassegrain telescope to detect explosives remotely for LIBS system. A design optimization of Schmidt corrector plate was carried out for Nd:YAG laser. Effect of different design parameters was investigated to eliminate spherical aberration in the system. Effect of different laser wavelengths on the Schmidt corrector design was also investigated for the standoff LIBS system.

  7. A dozen miners perish in W.Va. mine explosion

    Energy Technology Data Exchange (ETDEWEB)



    A report is given of the mine explosion which occurred at the Sago mine in Upshur County, WV, leaving 13 coal miners trapped underground. Only one of the 13 was found alive. The cause of the explosion might have been the miners' equipment igniting trapped methane. Early reports blamed a lightning strike. 2 photos.

  8. Effective protection of rabbits' explosive brain injury through blocking ...

    African Journals Online (AJOL)

    Background: The gap junction plays an important role in spreading of apoptotic and necrotic signals from injured and stressed cells to the neighboring viable cells. The present study was performed to investigate the important role of gap junction communication on rabbits' explosive brain injury. Methods: Explosion of paper ...

  9. Effect of Velocity of Detonation of Explosives on Seismic Radiation (United States)

    Stroujkova, A. F.; Leidig, M.; Bonner, J. L.


    We studied seismic body wave generation from four fully contained explosions of approximately the same yields (68 kg of TNT equivalent) conducted in anisotropic granite in Barre, VT. The explosions were detonated using three types of explosives with different velocities of detonation (VOD): Black Powder (BP), Ammonium Nitrate Fuel Oil/Emulsion (ANFO), and Composition B (COMP B). The main objective of the experiment was to study differences in seismic wave generation among different types of explosives, and to determine the mechanism responsible for these differences. The explosives with slow burn rate (BP) produced lower P-wave amplitude and lower corner frequency, which resulted in lower seismic efficiency (0.35%) in comparison with high burn rate explosives (2.2% for ANFO and 3% for COMP B). The seismic efficiency estimates for ANFO and COMP B agree with previous studies for nuclear explosions in granite. The body wave radiation pattern is consistent with an isotropic explosion with an added azimuthal component caused by vertical tensile fractures oriented along pre-existing micro-fracturing in the granite, although the complexities in the P- and S-wave radiation patterns suggest that more than one fracture orientation could be responsible for their generation. High S/P amplitude ratios and low P-wave amplitudes suggest that a significant fraction of the BP source mechanism can be explained by opening of the tensile fractures as a result of the slow energy release.

  10. Quick-closing valve is actuated by explosive discharge (United States)

    Majeski, S. J.


    Remotely controlled plug-type valve shuts off a high-pressure, high-temperature gas flow in a few milliseconds. The valve is actuated by a commercially available electrically initiated squib of low explosive power. More rapid closure is attainable with squibs containing heavier explosive changes.

  11. Evaluating of NASA-Langley Research Center explosion seam welding (United States)

    Otto, H. E.; Wittman, R.


    An explosion bonding technique to meet current fabrication requirements was demonstrated. A test program was conducted on explosion bonded joints, compared to fusion joints in 6061-T6 aluminum. The comparison was made in required fixtures, non-destructive testing, static strength and fatigue strength.

  12. Preparation of resistant sweet potato starch by steam explosion ...

    African Journals Online (AJOL)

    ... steam explosion (SE) technology. Methods: A response surface method was used to investigate the effects of explosion pressure, pressure-holding time and autoclaving time on digestion resistance of sweet potato starch. The resulting resistant sweet potato starch was identified by Fourier transform infrared spectroscopy ...

  13. 29 CFR 1926.860 - Selective demolition by explosives. (United States)


    ... 29 Labor 8 2010-07-01 2010-07-01 false Selective demolition by explosives. 1926.860 Section 1926.860 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Demolition § 1926.860 Selective demolition by explosives. Selective...

  14. 30 CFR 18.43 - Explosion-proof splice boxes. (United States)


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Explosion-proof splice boxes. 18.43 Section 18.43 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION... Design Requirements § 18.43 Explosion-proof splice boxes. Internal connections shall be rigidly held and...

  15. 33 CFR 154.820 - Fire, explosion, and detonation protection. (United States)


    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Fire, explosion, and detonation protection. 154.820 Section 154.820 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND... Systems § 154.820 Fire, explosion, and detonation protection. (a) A vapor control system with a single...

  16. 30 CFR 18.42 - Explosion-proof distribution boxes. (United States)


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Explosion-proof distribution boxes. 18.42 Section 18.42 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... and Design Requirements § 18.42 Explosion-proof distribution boxes. (a) A cable passing through an...

  17. A review of United Nations tests for explosivity

    NARCIS (Netherlands)

    Brown, A.K.; Mak, W.A.; Whitmore, M.W.


    In attempting to develop a closed pressure vessel test for assessing explosivity, arising from propagation of detonation, deflagration or thermal explosion, some difficulties were encountered in relation to United Nations test methods. This led to a review of these methods and comparisons of their

  18. Explosively-Driven Blast Waves in Small-Diameter Tubes (United States)

    Cooper, M. A.; Marinis, R. T.; Oliver, M. S.

    Studies on blast waves are motivated by the need to understand dynamic pressure loadings in accident scenarios associated with rapid energy release in confined geometries. Explosions from fuel-air mixtures, explosives and industrial accidents often occur within a range of length scales associated with ducts, pipes, corridors, and tunnels [1, 2].

  19. Explosive spread F caused by lightning-induced electromagnetic effects (United States)

    Liao, C. P.; Freidberg, J. P.; Lee, M. C.


    Lightning-produced electromagnetic effects may produce significant modifications in the ionospheric plasmas. An outstanding phenomenon investigated in this paper is the so-called explosive spread F, whose close link with lightning has been identified (Woodman and Kudeki, 1984). Parametric instability excited by the lightning-induced whistler waves is proposed as a potential source mechanism causing the explosive spread F.

  20. Explosive force of primacord grid forms large sheet metal parts (United States)


    Primacord which is woven through fish netting in a grid pattern is used for explosive forming of large sheet metal parts. The explosive force generated by the primacord detonation is uniformly distributed over the entire surface of the sheet metal workpiece.

  1. Nanostructured surface enhanced Raman scattering substrates for explosives detection

    DEFF Research Database (Denmark)

    Schmidt, Michael Stenbaek; Olsen, Jesper Kenneth; Boisen, Anja


    Here we present a method for trace detection of explosives in the gas phase using novel surface enhanced Raman scattering (SERS) spectroscopy substrates. Novel substrates that produce an exceptionally large enhancement of the Raman effect were used to amplify the Raman signal of explosives molecu...

  2. 46 CFR 189.25-47 - Chemical and explosive hazards. (United States)


    ... 46 Shipping 7 2010-10-01 2010-10-01 false Chemical and explosive hazards. 189.25-47 Section 189.25... INSPECTION AND CERTIFICATION Inspection for Certification § 189.25-47 Chemical and explosive hazards. (a) The marine inspector shall inspect every chemistry laboratory, scientific laboratory, and chemical storeroom...

  3. Controlled Detonation Dynamics in Additively Manufactured High Explosives (United States)

    Schmalzer, Andrew; Tappan, Bryce; Bowden, Patrick; Manner, Virginia; Clements, Brad; Menikoff, Ralph; Ionita, Axinte; Branch, Brittany; Dattelbaum, Dana; Espy, Michelle; Patterson, Brian; Wu, Ruilian; Mueller, Alexander


    The effect of structure in explosives has long been a subject of interest to explosives engineers and scientists. Through structure, detonation dynamics in explosives can be manipulated, introducing a new level of safety and directed performance into these previously difficult to control materials. New advances in additive manufacturing (AM) allow the deliberate introduction of exact internal structures at dimensions approaching the mesoscale of these energetic materials. We show through simulation and experiment that this structure can be used to control detonation behavior by manipulating complex shockwave interactions. We use high-speed video and shorting mag-wires to determine the detonation velocity in AM generated explosive structures, demonstrating, for the first time, a method of controlling the directional propagation of reactive flow through the controlled introduction of structure within a high explosive. With ongoing improvement in the AM methods available coupled with guidance through modeling and simulations, more complex interactions are being explored. LANL LDRD Office.

  4. Atmospheric structure from Phoenix atmospheric entry data (United States)

    Catling, D. C.


    The atmospheric structure at the time of landing of NASA's Phoenix probe has been derived from measurements of the aerodynamic drag of the spacecraft during atmospheric entry and descent. The result provides the first atmospheric structure in Mars' polar environment obtained from in situ measurements. Phoenix was equipped with an inertial measurement unit (IMU) that used accelerometers for linear acceleration measurement in three Cartesian axes and ring-laser gyroscopes to measure the three- dimensional orientation of the probe (Taylor et al., 2008). The temperature structure of the atmosphere along the flight path was calculated via a four-step process: (i) integrating forward the IMU data to obtain the time history of the spacecraft velocity vector relative to the atmosphere as a function of altitude; (ii) calculating atmospheric density from drag, with iteration for aerodynamic coefficient dependence on density; (iii) integrating the hydrostatic equation to derive the vertical pressure; and (iv) calculating atmospheric temperature from the equation of state. Initial profile reconstruction shows reasonable agreement with predictions in the middle atmosphere for the given season and time of day (landing occurred at 16h 33min 37sec in local solar time expressed as a 24-hour clock). However, the derived lower atmospheric structure below ~0.1 mbar is generally warmer than predicted. A possible explanation could be a shallower vertical distribution of dust that usually assumed. References: P. A. Taylor, D. C. Catling, M. Daly, C. S. Dickinson, H. O. Gunnlaugsson, A-M. Harri, C. F. Lange, Temperature, pressure and wind instrumentation on the Phoenix meteorological package, J. Geophys. Res., 113, EA0A10, doi:10.1029/2007JE003015, 2008.

  5. Planetary Atmospheric Electricity

    CERN Document Server

    Leblanc, F; Yair, Y; Harrison, R. G; Lebreton, J. P; Blanc, M


    This volume presents our contemporary understanding of atmospheric electricity at Earth and in other solar system atmospheres. It is written by experts in terrestrial atmospheric electricity and planetary scientists. Many of the key issues related to planetary atmospheric electricity are discussed. The physics presented in this book includes ionisation processes in planetary atmospheres, charge generation and separation, and a discussion of electromagnetic signatures of atmospheric discharges. The measurement of thunderstorms and lightning, including its effects and hazards, is highlighted by articles on ground and space based instrumentation, and new missions.Theory and modelling of planetary atmospheric electricity complete this review of the research that is undertaken in this exciting field of space science. This book is an essential research tool for space scientists and geoscientists interested in electrical effects in atmospheres and planetary systems. Graduate students and researchers who are new to t...

  6. Mirador - Atmospheric Composition (United States)

    National Aeronautics and Space Administration — Earth Science data access made simple. Atmospheric Composition is focused on the composition of Earth's atmosphere in relation to climate prediction, solar effects,...

  7. A mass spectrometer based explosives trace detector (United States)

    Vilkov, Andrey; Jorabchi, Kaveh; Hanold, Karl; Syage, Jack A.


    In this paper we describe the application of mass spectrometry (MS) to the detection of trace explosives. We begin by reviewing the issue of explosives trace detection (ETD) and describe the method of mass spectrometry (MS) as an alternative to existing technologies. Effective security screening devices must be accurate (high detection and low false positive rate), fast and cost effective (upfront and operating costs). Ion mobility spectrometry (IMS) is the most commonly deployed method for ETD devices. Its advantages are compact size and relatively low price. For applications requiring a handheld detector, IMS is an excellent choice. For applications that are more stationary (e.g., checkpoint and alternatives to IMS are available. MS is recognized for its superior performance with regard to sensitivity and specificity, which translate to lower false negative and false positive rates. In almost all applications outside of security where accurate chemical analysis is needed, MS is usually the method of choice and is often referred to as the gold standard for chemical analysis. There are many review articles and proceedings that describe detection technologies for explosives. 1,2,3,4 Here we compare MS and IMS and identify the strengths and weaknesses of each method. - Mass spectrometry (MS): MS offers high levels of sensitivity and specificity compared to other technologies for chemical detection. Its traditional disadvantages have been high cost and complexity. Over the last few years, however, the economics have greatly improved and MS is now capable of routine and automated operation. Here we compare MS and IMS and identify the strengths and weaknesses of each method. - Ion mobility spectrometry (IMS): 5 MS-ETD Screening System IMS is similar in concept to MS except that the ions are dispersed by gas-phase viscosity and not by molecular weight. The main advantage of IMS is that it does not use a vacuum system, which greatly reduces the size, cost, and complexity

  8. Analysis of different materials subjected to open-air explosions in search of explosive traces by Raman microscopy. (United States)

    Zapata, Félix; García-Ruiz, Carmen


    Post-explosion scenes offer such chaos and destruction that evidence recovery and detection of post-blast residues from the explosive in the surrounding materials is highly challenging and difficult. The suitability of materials to retain explosives residues and their subsequent analysis has been scarcely investigated. Particularly, the use of explosive mixtures containing inorganic oxidizing salts to make improvised explosive devices (IEDs) is a current security concern due to their wide availability and lax control. In this work, a wide variety of materials such as glass, steel, plywood, plastic bag, brick, cardboard or cotton subjected to open-air explosions were examined using confocal Raman microscopy, aiming to detect the inorganic oxidizing salts contained in explosives as black powder, chloratite, dynamite, ammonium nitrate fuel oil and ammonal. Post-blast residues were detected through microscopic examination of materials surfaces. In general, the more homogeneous and smoother the surface was, the less difficulties and better results in terms of identification were obtained. However, those highly irregular surfaces were the most unsuitable collectors for the posterior identification of explosive traces by Raman microscopy. The findings, difficulties and some recommendations related to the identification of post-blast particles in the different materials studied are thoroughly discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Atmospheric refraction : a history

    NARCIS (Netherlands)

    Lehn, WH; van der Werf, S


    We trace the history of atmospheric refraction from the ancient Greeks up to the time of Kepler. The concept that the atmosphere could refract light entered Western science in the second century B.C. Ptolemy, 300 years later, produced the first clearly defined atmospheric model, containing air of

  10. Representative Atmospheric Plume Development for Elevated Releases

    Energy Technology Data Exchange (ETDEWEB)

    Eslinger, Paul W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lowrey, Justin D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McIntyre, Justin I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Miley, Harry S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Prichard, Andrew W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)


    An atmospheric explosion of a low-yield nuclear device will produce a large number of radioactive isotopes, some of which can be measured with airborne detection systems. However, properly equipped aircraft may not arrive in the region where an explosion occurred for a number of hours after the event. Atmospheric conditions will have caused the radioactive plume to move and diffuse before the aircraft arrives. The science behind predicting atmospheric plume movement has advanced enough that the location of the maximum concentrations in the plume can be determined reasonably accurately in real time, or near real time. Given the assumption that an aircraft can follow a plume, this study addresses the amount of atmospheric dilution expected to occur in a representative plume as a function of time past the release event. The approach models atmospheric transport of hypothetical releases from a single location for every day in a year using the publically available HYSPLIT code. The effective dilution factors for the point of maximum concentration in an elevated plume based on a release of a non-decaying, non-depositing tracer can vary by orders of magnitude depending on the day of the release, even for the same number of hours after the release event. However, the median of the dilution factors based on releases for 365 consecutive days at one site follows a power law relationship in time, as shown in Figure S-1. The relationship is good enough to provide a general rule of thumb for estimating typical future dilution factors in a plume starting at the same point. However, the coefficients of the power law function may vary for different release point locations. Radioactive decay causes the effective dilution factors to decrease more quickly with the time past the release event than the dilution factors based on a non-decaying tracer. An analytical expression for the dilution factors of isotopes with different half-lives can be developed given the power law expression

  11. [Unexpected abdominal trauma from a fireworks explosion]. (United States)

    Smeulders, Mark J C; Gorter, Ramon R; Cense, Huib A; van Trier, A Toine


    Fireworks injuries are common and often affect children. Such injuries should be considered high energy trauma in the emergency room and taken care of according to the principles of the Advanced Trauma Life Support (ATLS). A 7-year-old boy was a victim of an explosion when he set off illegal fireworks. During evaluation in the emergency department he presented with a superficial laceration on the belly and extensive hand injury. Upon examination he had small-intestinal perforation that required immediate resection. The patient recovered well, but suffered permanent damage to the hand. Potentially life threatening injuries may accompany hand injuries after modern illegal fireworks. Hand injuries are serious. Despite prolonged treatment, they often result in permanent disability. The structured approach to trauma according to ATLS was important in detecting an accompanying abdominal trauma in this case.

  12. Tabletop Nucleosynthesis Driven by Cluster Coulomb Explosion (United States)

    Last, Isidore; Jortner, Joshua


    Coulomb explosion of completely ionized (CH4)n, (NH3)n, and (H2O)n clusters will drive tabletop nuclear reactions of protons with C6+12, N7+14, and O8+16 nuclei, extending the realm of nuclear reactions driven by ultraintense laser-heterocluster interaction. The realization for nucleosynthesis in exploding cluster beams requires complete electron stripping from the clusters (at laser intensities IM≥1019Wcm-2), the utilization of nanodroplets of radius 300 700 Å for vertical ionization, and the attainment of the highest energies for the nuclei (i.e., ˜30MeV for heavy nuclei and ˜3MeV for protons).

  13. Multistage reaction pathways in detonating high explosives

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ying [Collaboratory for Advanced Computing and Simulations, Department of Physics and Astronomy, Department of Computer Science, and Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-0242 (United States); Argonne Leadership Computing Facility, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Kalia, Rajiv K.; Nakano, Aiichiro; Nomura, Ken-ichi; Vashishta, Priya [Collaboratory for Advanced Computing and Simulations, Department of Physics and Astronomy, Department of Computer Science, and Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-0242 (United States)


    Atomistic mechanisms underlying the reaction time and intermediate reaction products of detonating high explosives far from equilibrium have been elusive. This is because detonation is one of the hardest multiscale physics problems, in which diverse length and time scales play important roles. Here, large spatiotemporal-scale reactive molecular dynamics simulations validated by quantum molecular dynamics simulations reveal a two-stage reaction mechanism during the detonation of cyclotrimethylenetrinitramine crystal. Rapid production of N{sub 2} and H{sub 2}O within ∼10 ps is followed by delayed production of CO molecules beyond ns. We found that further decomposition towards the final products is inhibited by the formation of large metastable carbon- and oxygen-rich clusters with fractal geometry. In addition, we found distinct unimolecular and intermolecular reaction pathways, respectively, for the rapid N{sub 2} and H{sub 2}O productions.

  14. Study on Coulomb explosions of ion mixtures

    CERN Document Server

    Boella, E; D'Angola, A; Coppa, G; Silva, L O


    The paper presents a theoretical work on the dynamics of Coulomb explosion for spherical nanoplasmas composed by two different ion species. Particular attention has been dedicated to study the energy spectra of the ions with the larger charge-to-mass ratio. The connection between the formation of shock shells and the energy spread of the ions has been the object of a detailed analysis, showing that under particular conditions the width of the asymptotic energy spectrum tends to become very narrow, which leads to a multi-valued ion phase-space. The conditions to generate a quasi mono-energetic ion spectrum have been rigorously demonstrated and verifed by numerical simulations, using a technique that, exploiting the spherical symmetry of the problem, allows one to obtain very accurate and precise results.

  15. Development of Speditive Explosibility Test (SET): a statistical reliable method for combustible dust explosibility investigation


    Danzi, Enrico


    The present work of thesis investigate the explosibility sensitivity and behavior of combustible solid materials, in the form of dusts. The first phase of the work has focused on the ignition sensitivity of combustible dusts, both in form of clouds than deposed as layers. Standard test methods has been used to assess ignition parameter of the samples, i.e. UNI EN 50821: 1999. MITC and MITL were measured for pure combustible dusts and for mixtures of different dusts. In particular mixtures of ...

  16. Explosion-Earthquake Discrimination at Local Distances (United States)

    O'Rourke, C. T.; Baker, G. E.; Sheehan, A. F.; Harder, S. H.


    Event discrimination research has largely focused on regional distances over the last couple of decades. Most regional discriminants have not been thoroughly tested at local distances, and a recent investigation of P/S ratios from the Source Physics Experiment (SPE) found that they were less effective locally. As discrimination thresholds are reduced, local methods will need to be validated and the physical bases for their performance will need to be understood. We are assessing new and existing methods of source discrimination at 10 to 200 km distance. We use data from a temporary array deployed around the Bighorn Mountains in Wyoming and from nearby US Array stations. Small magnitude local earthquakes, coal mine explosions, and controlled borehole shots were recorded at over 200 broadband and short-period seismometers spaced at 5-35 km intervals across the tectonically complex area. We assess the local discrimination performance of the P/S amplitude ratio, the presence of the fundamental Rayleigh wave Rg, and the signature of scattered Rg in the coda. P/S amplitudes are used because earthquakes typically have higher S-wave energy relative to P than shallow explosions, but the separation of populations is not always effective at local distances. Site effects have a significant impact that may need to be accounted for, along with propagation effects. Specifically, relative P and S site amplifications at basin and mountain stations vary in such a way that they limit separation of the event populations. The Rg phase is only excited by near-surface events, so its presence indicates the likelihood of a man-made source since most earthquakes occur at too great a depth to excite Rg. We implement two methods for detecting Rg: one that uses the cross-correlation of the Hilbert transformed vertical and the radial seismograms, and one that scans a time-frequency representation for the signature of scattered Rg in the coda. These methods are effective in low signal

  17. [Intermittent Explosive Disorder: A Controversial Diagnosis]. (United States)

    Zapata, Juan Pablo; Palacio, Juan David


    Intermittent explosive disorder (IED) is aan externalizing externalising disorder characterized characterised by recurrent aggression episodes. Even though this disorder was described several decades ago, and it carries personal and social consequences, there is little in the medical scientific literature on this. bibliographic production about it is scanty. To perform a conceptualization conceptualisation of this disorder, through the review and bibliometric analysis of the available scientific articles. A search was performed in databases with the english English terms intermittent explosive disorder, impulse disorders control [MeSH], in combination with other terms. A bibliometric analysis in the GoPubMed® search engineer was also performed using all data obtained in the search. was also perfomed. IED prevalence ranges from 1.4% to 7%, it presents more frequently during middle adolescence, and with more noticeable repercussions in men males than in womenfemales. The psychopathological core of IED is the impulsive aggressive behaviour that presents in the form of «attacks» that occurs in response to a lower precipitating stimulus. Scientific publications about IED are few and relatively recent, and the vast majority is provided bycomes from the United States (56.56%), and headed by a single author. This fact highlights the need to replicate the findings described about the IED in order to demonstrate the validity and reliability of its diagnostic criteria. It is possible that doubts about the existence of a diagnosis lead have led to such a scant literature about the IED. Available studies about IED allow have allowed characterizing a group of subjects with episodes of impulsive aggression to be characterised, but this description requires replication in different latitudesneeds to be repeated in different areas. Copyright © 2015 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  18. Online Optimization Applied to a Shockless Explosion Combustor

    Directory of Open Access Journals (Sweden)

    Jan-Simon Schäpel


    Full Text Available Changing the combustion process of a gas turbine from a constant-pressure to a pressure-increasing approximate constant-volume combustion (aCVC is one of the most promising ways to increase the efficiency of turbines in the future. In this paper, a newly proposed method to achieve such an aCVC is considered. The so-called shockless explosion combustion (SEC uses auto-ignition and a fuel stratification to achieve a spatially homogeneous ignition. The homogeneity of the ignition can be adjusted by the mixing of fuel and air. A proper filling profile, however, also depends on changing parameters, such as temperature, that cannot be measured in detail due to the harsh conditions inside the combustion tube. Therefore, a closed-loop control is required to obtain an adequate injection profile and to reject such unknown disturbances. For this, an optimization problem is set up and a novel formulation of a discrete extremum seeking controller is presented. By approximating the cost function with a parabola, the first derivative and a Hessian matrix are estimated, allowing the controller to use Newton steps to converge to the optimal control trajectory. The controller is applied to an atmospheric test rig, where the auto-ignition process can be investigated for single ignitions. In the set-up, dimethyl ether is injected into a preheated air stream using a controlled proportional valve. Optical measurements are used to evaluate the auto-ignition process and to show that using the extremum seeking control approach, the homogeneity of the ignition process can be increased significantly.

  19. Research on Initiation Sensitivity of Solid Explosive and Planer Initiation System

    Directory of Open Access Journals (Sweden)

    N Matsuo


    Full Text Available Firstly, recently, there are a lot of techniques being demanded for complex process, various explosive initiation method and highly accurate control of detonation are needed. In this research, the metal foil explosion using high current is focused attention on the method to obtain linear or planate initiation easily, and the main evaluation of metal foil explosion to initiate explosive was conducted. The explosion power was evaluated by observing optically the underwater shock wave generated from the metal foil explosion. Secondly, in high energy explosive processing, there are several applications, such as shock compaction, explosive welding, food processing and explosive forming. In these explosive applications, a high sensitive explosive has been mainly used. The high sensitive explosive is so dangerous, since it can lead to explosion suddenly. So, for developing explosives, the safety is the most important thing as well as low manufacturing cost and explosive characteristics. In this work, we have focused on the initiation sensitivity of a solid explosive and performed numerical analysis of sympathetic detonation. The numerical analysis is calculated by LS-DYNA 3D (commercial code. To understand the initiation reaction of an explosive, Lee-Tarver equation was used and impact detonation process was analyzed by ALE code. Configuration of simulation model is a quarter of circular cylinder. The donor type of explosive (SEP was used as initiation explosive. When the donor explosive is exploded, a shock wave is generated and it propagates into PMMA, air and metallic layers in order. During passing through the layers, the shock wave is attenuated and finally, it has influence on the acceptor explosive, Comp. B. Here, we evaluate the initiation of acceptor explosive and discuss about detonation pressure, reactive rate of acceptor explosive and attenuation of impact pressure.

  20. Atmospheric Habitable Zones in Y Dwarf Atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Yates, Jack S.; Palmer, Paul I. [School of GeoSciences, University of Edinburgh (United Kingdom); Biller, Beth; Cockell, Charles S., E-mail: [Centre for Exoplanet Science, University of Edinburgh (United Kingdom)


    We use a simple organism lifecycle model to explore the viability of an atmospheric habitable zone (AHZ), with temperatures that could support Earth-centric life, which sits above an environment that does not support life. To illustrate our model, we use a cool Y dwarf atmosphere, such as WISE J085510.83–0714442.5, whose 4.5–5.2 μ m spectrum shows absorption features consistent with water vapor and clouds. We allow organisms to adapt to their atmospheric environment (described by temperature, convection, and gravity) by adopting different growth strategies that maximize their chance of survival and proliferation. We assume a constant upward vertical velocity through the AHZ. We found that the organism growth strategy is most sensitive to the magnitude of the atmospheric convection. Stronger convection supports the evolution of more massive organisms. For a purely radiative environment, we find that evolved organisms have a mass that is an order of magnitude smaller than terrestrial microbes, thereby defining a dynamical constraint on the dimensions of life that an AHZ can support. Based on a previously defined statistical approach, we infer that there are of the order of 10{sup 9} cool Y brown dwarfs in the Milky Way, and likely a few tens of these objects are within 10 pc from Earth. Our work also has implications for exploring life in the atmospheres of temperate gas giants. Consideration of the habitable volumes in planetary atmospheres significantly increases the volume of habitable space in the galaxy.

  1. Effects of charge design features on parameters of acoustic and seismic waves and cratering, for SMR chemical surface explosions (United States)

    Gitterman, Y.


    A series of experimental on-surface shots was designed and conducted by the Geophysical Institute of Israel at Sayarim Military Range (SMR) in Negev desert, including two large calibration explosions: about 82 tons of strong IMI explosives in August 2009, and about 100 tons of ANFO explosives in January 2011. It was a collaborative effort between Israel, CTBTO, USA and several European countries, with the main goal to provide fully controlled ground truth (GT0) infrasound sources in different weather/wind conditions, for calibration of IMS infrasound stations in Europe, Middle East and Asia. Strong boosters and the upward charge detonation scheme were applied to provide a reduced energy release to the ground and an enlarged energy radiation to the atmosphere, producing enhanced infrasound signals, for better observation at far-regional stations. The following observations and results indicate on the required explosives energy partition for this charge design: 1) crater size and local seismic (duration) magnitudes were found smaller than expected for these large surface explosions; 2) small test shots of the same charge (1 ton) conducted at SMR with different detonation directions showed clearly lower seismic amplitudes/energy and smaller crater size for the upward detonation; 3) many infrasound stations at local and regional distances showed higher than expected peak amplitudes, even after application of a wind-correction procedure. For the large-scale explosions, high-pressure gauges were deployed at 100-600 m to record air-blast properties, evaluate the efficiency of the charge design and energy generation, and provide a reliable estimation of the charge yield. Empirical relations for air-blast parameters - peak pressure, impulse and the Secondary Shock (SS) time delay - depending on distance, were developed and analyzed. The parameters, scaled by the cubic root of estimated TNT equivalent charges, were found consistent for all analyzed explosions, except of SS

  2. Infrasonic and seismic signals from earthquakes and explosions observed with Plostina seismo-acoustic array (United States)

    Ghica, D.; Ionescu, C.


    Plostina seismo-acoustic array has been recently deployed by the National Institute for Earth Physics in the central part of Romania, near the Vrancea epicentral area. The array has a 2.5 km aperture and consists of 7 seismic sites (PLOR) and 7 collocated infrasound instruments (IPLOR). The array is being used to assess the importance of collocated seismic and acoustic sensors for the purposes of (1) seismic monitoring of the local and regional events, and (2) acoustic measurement, consisting of detection of the infrasound events (explosions, mine and quarry blasts, earthquakes, aircraft etc.). This paper focuses on characterization of infrasonic and seismic signals from the earthquakes and explosions (accidental and mining type). Two Vrancea earthquakes with magnitude above 5.0 were selected to this study: one occurred on 1st of May 2011 (MD = 5.3, h = 146 km), and the other one, on 4th October 2011 (MD = 5.2, h = 142 km). The infrasonic signals from the earthquakes have the appearance of the vertical component of seismic signals. Because the mechanism of the infrasonic wave formation is the coupling of seismic waves with the atmosphere, trace velocity values for such signals are compatible with the characteristics of the various seismic phases observed with PLOR array. The study evaluates and characterizes, as well, infrasound and seismic data recorded from the explosion caused by the military accident produced at Evangelos Florakis Naval Base, in Cyprus, on 11th July 2011. Additionally, seismo-acoustic signals presumed to be related to strong mine and quarry blasts were investigated. Ground truth of mine observations provides validation of this interpretation. The combined seismo-acoustic analysis uses two types of detectors for signal identification: one is the automatic detector DFX-PMCC, applied for infrasound detection and characterization, while the other one, which is used for seismic data, is based on array processing techniques (beamforming and frequency

  3. Molecular Dications in Planetary Atmospheric Escape

    Directory of Open Access Journals (Sweden)

    Stefano Falcinelli


    Full Text Available Fundamental properties of multiply charged molecular ions, such as energetics, structure, stability, lifetime and fragmentation dynamics, are relevant to understand and model the behavior of gaseous plasmas as well as ionosphere and astrophysical environments. Experimental determinations of the Kinetic Energy Released (KER for ions originating from dissociations reactions, induced by Coulomb explosion of doubly charged molecular ions (molecular dications produced by double photoionization of CO2, N2O and C2H2 molecules of interest in planetary atmospheres, are reported. The KER measurement as a function of the ultraviolet (UV photon energy in the range of 28–65 eV was extracted from the electron-ion-ion coincidence spectra obtained by using tunable synchrotron radiation coupled with ion imaging techniques at the ELETTRA Synchrotron Light Laboratory Trieste, Italy. These experiments, coupled with a computational analysis based on a Monte Carlo trajectory simulation, allow assessing the probability of escape for simple ionic species in the upper atmosphere of Mars, Venus and Titan. The measured KER in the case of H+, C+, CH+, CH2+, N+, O+, CO+, N2+ and NO+ fragment ions range between 1.0 and 5.5 eV, being large enough to allow these ionic species to participate in the atmospheric escape from such planets into space. In the case of Mars, we suggest a possible explanation for the observed behavior of the O+ and CO22+ ion density profiles.

  4. Stellar survivor from explosion in 1572 AD (United States)


    hi-res Size hi-res: 1051 kb Credits: NASA/ESA, CXO and P. Ruiz-Lapuente (University of Barcelona) Tycho's Supernova, SN 1572A These images show the location of a suspected runaway companion star to a titanic supernova explosion witnessed in the year 1572 by the Danish astronomer Tycho Brahe and other astronomers of that era. This discovery provides the first direct evidence supporting the long-held belief that Type Ia supernovae come from binary star systems containing a normal star and a burned-out white dwarf star. When the dwarf ultimately explodes by being overfueled by the companion star, the companion is slung away from the demised star. The Hubble Space Telescope played a key role by precisely measuring the surviving star's motion against the sky background. Right: A Hubble Space Telescope Wide Field Planetary Camera 2 image of a small section of sky containing the candidate star. The star is like our Sun except several thousand million years older. It is moving through space at three times the speed of the other stars in its neighbourhood. Hubble's sharp view allowed for a measurement of the star's motion, based on images taken in 1999 and 2003. The image consists of a single greyscale Hubble exposure colourised with the help of data from Digitized Sky Survey 2. Left: The Hubble view is superimposed on this wide-field view of the region enveloped by the expanding bubble of the supernova explosion; the bubble and candidate star are at approximately the same distance, 10 000 light-years. The star is noticeably offset from the geometric centre of the bubble. The colours in the Chandra X-Ray image of the hot bubble show different X-ray energies, with red, green and blue representing low, medium and high energies, respectively. (The image is cut off at the bottom because the southernmost region of the remnant fell outside the field of view of the Chandra camera.) hi-res Size hi-res: 1059 kb Credits: NASA/ESA and P. Ruiz-Lapuente (University of Barcelona) The

  5. Infrasound and the Infrasonic Monitoring or Atmospheric Nuclear Explosions: An Annotated Bibliography

    National Research Council Canada - National Science Library

    McKisic, J


    ... institutions interested in the technical aspects of infrasound, in general, and in the particular use of infrasound to monitor compliance within the context of a comprehensive nuclear test ban treaty (CTBT...

  6. Light Initiated High Explosives (LIHE) Test Technique and Capabilities (United States)

    Covert, Timothy


    The Light Initiated High Explosives (LIHE) test facility has been re-established and chartered to impart impulsive loads to a variety of targets. This loading is achieved through the detonation of a primary explosive applied directly to the target surface using a robotic spraying system. Using light as the initiating mechanism ensures virtually simultaneous loading. Uniform, discontinuous, or graded explosive loading conditions are achievable over complex shapes with the LIHE process. This direct detonation technique is a demonstrated capability at the LIHE facility. Test results will be presented. In addition to the direct detonation technique, the LIHE facility is developing the capability to explosively accelerate a thin flyer plate to impact various test targets. This explosively accelerated flyer plate (X-Flyer) will enable pressure control during impulsive loading. By controlling flyer density (material), thickness, velocity, and acceleration gap, the impact pressure amplitude and pulse duration can be controlled. Similar to the direct detonation technique, a primary explosive is robotically sprayed onto the flyer plate and subsequently detonated using an intense flash of light. Through the control of the explosive deposition and flyer gap, virtually simultaneous impact is achievable for either uniform or graded loading conditions. X-Flyer test results will be presented.

  7. Modelling and simulation of gas explosions in complex geometries

    Energy Technology Data Exchange (ETDEWEB)

    Saeter, Olav


    This thesis presents a three-dimensional Computational Fluid Dynamics (CFD) code (EXSIM94) for modelling and simulation of gas explosions in complex geometries. It gives the theory and validates the following sub-models : (1) the flow resistance and turbulence generation model for densely packed regions, (2) the flow resistance and turbulence generation model for single objects, and (3) the quasi-laminar combustion model. It is found that a simple model for flow resistance and turbulence generation in densely packed beds is able to reproduce the medium and large scale MERGE explosion experiments of the Commission of European Communities (CEC) within a band of factor 2. The model for a single representation is found to predict explosion pressure in better agreement with the experiments with a modified k-{epsilon} model. This modification also gives a slightly improved grid independence for realistic gas explosion approaches. One laminar model is found unsuitable for gas explosion modelling because of strong grid dependence. Another laminar model is found to be relatively grid independent and to work well in harmony with the turbulent combustion model. The code is validated against 40 realistic gas explosion experiments. It is relatively grid independent in predicting explosion pressure in different offshore geometries. It can predict the influence of ignition point location, vent arrangements, different geometries, scaling effects and gas reactivity. The validation study concludes with statistical and uncertainty analyses of the code performance. 98 refs., 96 figs, 12 tabs.

  8. Parameters affecting the thermal behaviour of emulsion explosives

    Energy Technology Data Exchange (ETDEWEB)

    Jones, D.E.G.; Feng, H.; Mintz, K.J.; Augsten, R.A. [Natural Resources Canada, Ottawa, ON (Canada). Canadian Explosives Research Laboratory


    Accelerating rate calorimetry (ARC) and heat flux calorimetry (HFC) were used to study the sensitivity of ammonium nitrate (AN) and emulsion explosives to pressure and various other parameters. The explosives were evaluated in a series of experiments that examined the influence of pressure in both Argon and air environments at 5.4 MPa. Results of the study demonstrated that significantly lower onset temperatures were observed when the ammonium nitrate (AN) explosive was used in air. Results of the ARC study suggested that lower initial temperatures resulted in an elevated onset temperature. Lower onset temperatures observed in the study were attributed to oxidation of the oil phase in the emulsion. Onset temperatures for the AN explosive were lower than rates observed for the emulsion explosives. The size of the samples also influenced onset temperatures in both the ARC and HFC analyses. At heating rates of 0.1 degrees C per minute, the results of heat flux calorimetry revealed a complex exotherm pattern for the emulsion explosive in both Argon and in air. The high pressure of inert gas inhibited and delayed the exothermic reactions for the emulsion explosives. It was concluded that air-oxidative decomposition results in lower onset temperatures that are influenced by higher pressure rates. 8 refs., 3 tabs., 8 figs.

  9. Aluminum-Enhanced Underwater Electrical Discharges for Steam Explosion Triggering

    Energy Technology Data Exchange (ETDEWEB)



    For a number of years, we have been initiating steam explosions of single drops of molten materials with pressure and flow (bubble growth) transients generated by discharging a capacitor bank through gold bridgewires placed underwater. Recent experimental and theoretical advances in the field of steam explosions, however, have made it important to substantially increase these relatively mild transients in water without using high explosives, if possible. To do this with the same capacitor bank, we have discharged similar energies through tiny strips of aluminum foil submerged in water. By replacing the gold wires with the aluminum strips, we were able to add the energy of the aluminum-water combustion to that normally deposited electrically by the bridgewire explosion in water. The chemical enhancement of the explosive characteristics of the discharges was substantial: when the same electrical energies were discharged through the aluminum strips, peak pressures increased as much as 12-fold and maximum bubble volumes as much as 5-fold above those generated with the gold wires. For given weights of aluminum, the magnitudes of both parameters appeared to exceed those produced by the underwater explosion of equivalent weights of high explosives.

  10. Green primary explosives: 5-nitrotetrazolato-N2-ferrate hierarchies. (United States)

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


    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 military and civilian purposes continues to expand owing to variations in initiating method, chemical composition, quantity, sensitivity, explosive performance, and other necessary built-in mechanisms. Although the most widely used primaries contain toxic lead azide and lead styphnate, mixtures of thermally unstable primaries, like diazodinitrophenol and tetracene, or poisonous agents, like antimony sulfide and barium nitrate, are also used. Novel environmentally friendly primary explosives are expanded here to include cat[Fe(II)(NT)(3)(H(2)O)(3)], cat(2)[Fe(II)(NT)(4)(H(2)O)(2)], cat(3)[Fe(II)(NT)(5)(H(2)O)], and cat(4)[Fe(II)(NT)(6)] with cat = cation and NT(-) = 5-nitrotetrazolato-N(2). With available alkaline, alkaline earth, and organic cations as partners, four series of 5-nitrotetrazolato-N(2)-ferrate hierarchies have been prepared that provide a plethora of green primaries with diverse initiating sensitivity and explosive performance. They hold great promise for replacing not only toxic lead primaries but also thermally unstable primaries and poisonous agents. Strategies are also described for the systematic preparation of coordination complex green primaries based on appropriate selection of ligands, metals, and synthetic procedures. These strategies allow for maximum versatility in initiating sensitivity and explosive performance while retaining properties required for green primaries.

  11. Numerical Simulation of Explosive Forming Using Detonating Fuse

    Directory of Open Access Journals (Sweden)

    H Iyama


    Full Text Available The explosive forming is a characteristic method. An underwater shock wave is generated by underwater explosion of an explosive. A metal plate is affected high strain rate by the shock loading and is formed along a metal die. Although this method has the advantage of mirroring the shape of the die, a free forming was used in this paper. An expensive metal die is not necessary for this free forming. It is possible that a metal plate is formed with simple supporting parts. However, the forming shape is depend on the shock pressure distribution act on the metal plate. This pressure distribution is able to change by the shape of explosive, a mass of explosive and a shape of pressure vessel. On the other hand, we need the pressure vessel for food processing by the underwater shock wave. Therefore, we propose making the pressure vessel by this explosive forming. One design suggestion of pressure vessel made of stainless steel was considered. However, we cannot decide suitable conditions, the mass of the explosive and the distance between the explosive and the metal plate to make the pressure vessel. In order to decide these conditions, we have tried the numerical simulation on this explosive forming. The basic simulation method was ALE (Arbitrary Laglangian Eulerian method including with Mie-Grümeisen EOS (equation of state, JWL EOS, Johnson-Cook constitutive equation for a material model. In this paper, the underwater pressure contours to clear the propagations of the underwater shock wave, forming processes and deformation velocity of the metal plate is shown and it will be discussed about those results.

  12. Progress in Three-Dimensional Simulations of Explosions and Earthquakes (United States)


    parallel computers are making it easier to simulate ground motions on the scale lengths (domain sizes) and frequencies (resolutions) of importance to nuclear explosion monitoring. The objective of this research is to develop and improve methods for seismic simulation in fully 3D earth models to improve nuclear explosion monitoring. Specifically, research is directed along three thrusts: modeling of shock-wave propagation with hydrodynamic methods; modeling of elastic propagation near shallow explosions and earthquakes, including the effect of 3D volumetric structure and

  13. Numerical Simulation of Explosive Forming Using Detonating Fuse


    H Iyama; Higa, Y.; Nishi, M.; Itoh, S.


    The explosive forming is a characteristic method. An underwater shock wave is generated by underwater explosion of an explosive. A metal plate is affected high strain rate by the shock loading and is formed along a metal die. Although this method has the advantage of mirroring the shape of the die, a free forming was used in this paper. An expensive metal die is not necessary for this free forming. It is possible that a metal plate is formed with simple supporting parts. However, the forming ...

  14. Spraying explosive formulations. [Quarterly report], July--September 1970

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, G.T.


    A composition of 98/2 weight percent PETN/polybutadiene elastomer was formulated, sprayed on bridgewires and electrically initiated, to determine the,feasibility of such deposition of explosives bonded to test surfaces. Test firing resulted in a detonation reaction which could mean that explosive compositions sprayed on test surfaces may be an important tool in testing structural integrity, e.g., as presently in the Vulnerability Testing Program. A semi-automatic apparatus for spraying explosive formulations on chemically etched electric circuits, support membranes and/or test vehicle surfaces has been designed, and improved application processes are being developed.

  15. A new seismic discriminant for earthquakes and explosions (United States)

    Woods, Bradley B.; Helmberger, Donald V.

    With the spread of nuclear weapons technology, more regions of the world need to be monitored in order to verify nuclear nonproliferation and limited test-ban treaties. Seismic monitoring is the primary means to remotely sense contained underground explosions “Bolt, 1976; Dahlman and Israelson, 1977”. Both underground explosions and earthquakes generate seismic energy, which propagates through the Earth as elastic waves. The crux of the verification problem is to differentiate between the seismic signatures of explosions and earthquakes. Such identification is most difficult in countries with seismically active areas, where bombs might be detonated to blend in with the region's natural seismicity.

  16. Sensor distribution design of travel time tomography in explosion. (United States)

    Guo, Yali; Han, Yan; Wang, Liming; Liu, Linmao


    Optimal sensor distribution in explosion testing is important in saving test costs and improving experiment efficiency. Aiming at travel time tomography in an explosion, an optimizing method in sensor distribution is proposed to improve the inversion stability. The influence factors of inversion stability are analyzed and the evaluating function on optimizing sensor distribution is proposed. This paper presents a sub-region and multi-scale cell partition method, according to the characteristics of a shock wave in an explosion. An adaptive escaping particle swarm optimization algorithm is employed to achieve the optimal sensor distribution. The experimental results demonstrate that optimal sensor distribution has improved both indexes and inversion stability.

  17. Electric conductivity of high explosives with carbon nanotubes (United States)

    Rubtsov, I. A.; Pruuel, E. R.; Ten, K. A.; Kashkarov, A. O.; Kremenko, S. I.


    The paper presents a technique for introducing carbon nanotubes into high explosives (HEs). For a number of explosives (trinitrotoluene, pentaerythritol tetranitrate, benzotrifuroxan), it was possible to achieve the appearance of conductivity by adding a small amount (up to 1% by mass) of single-walled carbon nanotubes TUBALL COATE H2O (CNTs) produced by OCSiAl. Thus it is possible to reduce the sensitivity of explosives to static electricity by adding an insignificant part of conductive nanotubes. This will increase safety of HEs during production and application and will reduce the number of accidents.

  18. The geometry of Strombolian explosions: insights from Doppler radar measurements (United States)

    Gouhier, Mathieu; Donnadieu, Franck


    Observations of Strombolian volcanic explosions were carried out at Etna's southeast crater on 2001 July 4 using a ground-based pulsed Doppler radar (VOLDORAD). To obtain quantitative constraints on the geometry of the explosions, we modelled synthetic Doppler spectra by combining the outputs of a ballistic model to compute the theoretical velocities of gas and particles, and an electromagnetic scattering model to calculate the synthetic echo power. This allowed us to reproduce the shapes of recorded Doppler spectra for each volcanic explosion. We examined the geometrical distribution of ejected pyroclasts for about 200 explosions and found two main types of explosion, each showing a distinctive spectral signature. The first type, characterized by the triangular shape of their Doppler spectra, represents 34 per cent of the explosions. This spectrum shape is related to a Gaussian distribution of the pyroclast ejection angles, where most of the volcanic material is ejected vertically within a narrow cone, with the particle concentration decreasing radially. The second type represents about 12 per cent of the explosions, and is characterized by a top-hat-shaped spectrum. It is produced by a uniform distribution of pyroclast ejection angles. In this case, the bubbles tend to burst above the crater rim and eject the ballistic clasts hemispherically without preferential orientation. The majority of the Strombolian explosions analysed (54 per cent) are intermediate between these end-member shapes, and show a triangular spectra truncated by a plateau. They result from a uniform distribution of ejection angles around the jet axis. The continuous radar recordings allowed us to carry out a statistical analysis on the geometrical features of the same 200 Strombolian explosions. Thus we find that 40° is a statistically representative aperture of the dispersion cone characterized by uniform ejecta distribution for explosions having a plateau component (i.e. 2/3 of all

  19. Type Ia supernovae: explosions and progenitors (United States)

    Kerzendorf, Wolfgang Eitel


    Supernovae are the brightest explosions in the universe. Supernovae in our Galaxy, rare and happening only every few centuries, have probably been observed since the beginnings of mankind. At first they were interpreted as religious omens but in the last half millennium they have increasingly been used to study the cosmos and our place in it. Tycho Brahe deduced from his observations of the famous supernova in 1572, that the stars, in contrast to the widely believe Aristotelian doctrine, were not immutable. More than 400 years after Tycho made his paradigm changing discovery using SN 1572, and some 60 years after supernovae had been identified as distant dying stars, two teams changed the view of the world again using supernovae. The found that the Universe was accelerating in its expansion, a conclusion that could most easily be explained if more than 70% of the Universe was some previously un-identified form of matter now often referred to as `Dark Energy'. Beyond their prominent role as tools to gauge our place in the Universe, supernovae themselves have been studied well over the past 75 years. We now know that there are two main physical causes of these cataclysmic events. One of these channels is the collapse of the core of a massive star. The observationally motivated classes Type II, Type Ib and Type Ic have been attributed to these events. This thesis, however is dedicated to the second group of supernovae, the thermonuclear explosions of degenerate carbon and oxygen rich material and lacking hydrogen - called Type Ia supernovae (SNe Ia). White dwarf stars are formed at the end of a typical star's life when nuclear burning ceases in the core, the outer envelope is ejected, with the degenerate core typically cooling for eternity. Theory predicts that such stars will self ignite when close to 1.38 Msun (called the Chandrasekhar Mass). Most stars however leave white dwarfs with 0.6 Msun, and no star leaves a remnant as heavy as 1.38 M! sun, which suggests

  20. Stability of volcanic conduits during explosive eruptions (United States)

    Aravena, Álvaro; de'Michieli Vitturi, Mattia; Cioni, Raffaello; Neri, Augusto


    Geological evidences of volcanic conduit widening are common in most pyroclastic deposits (e.g. presence of lithic fragments from different depths), suggesting a continuous modification of the conduit geometry during volcanic eruptions. However, the controlling factors of the mechanisms driving conduit enlargement (e.g. erosion, local collapse) are still partially unclear, as well as the influence of conduit geometry on the eruptive dynamics. Although numerical models have been systematically employed to study volcanic conduits, their mechanical stability and the eruptive dynamics related to non-cylindrical conduits have been poorly addressed. We present here a 1D steady-state model which includes the main processes experimented by ascending magmas (i.e. crystallization, rheological changes, fragmentation, drag forces, outgassing and degassing), and the application of two mechanical stability criteria (Mohr-Coulomb and Mogi-Coulomb), in order to study the collapse conditions of volcanic conduits during a representative explosive rhyolitic eruption. It emerges that mechanical stability of volcanic conduits is mainly controlled by its radial dimension, and a minimum radius for reaching stable conditions can be computed, as a function of water content and inlet overpressure. Additionally, for a set of input parameters thought typical of explosive rhyolitic volcanism, we estimated a minimum magma flux for developing a mechanically stable conduit ( 7 • 107 - 3 • 108 kg/s). Results are consistent with the unsteady character usually observed in sub-Plinian eruptions, opposite to mainly stationary Plinian eruptions, commonly characterized by higher magma discharge rates. We suggest that cylindrical conduits represent a mechanically stable configuration only for large radii. Because the instability conditions are not uniform along the conduit, the widening processes probably lead to conduit geometries with depth-varying width. Consequently, as our model is able to

  1. Explosive Strength Imbalances in Professional Basketball Players (United States)

    Schiltz, Marc; Lehance, Cédric; Maquet, Didier; Bury, Thierry; Crielaard, Jean-Michel; Croisier, Jean-Louis


    Context: Despite the high rate of lower limb injuries in basketball players, studies of the dominant-limb effect in elite athletes often neglect injury history. Objective: To determine lower limb explosive-strength asymmetries in professional basketball players compared with junior basketball players and control participants. Design: Cohort study. Setting: Academic medical institution. Patients or Other Participants: 15 professional basketball players, 10 junior basketball players, and 20 healthy men. Main Outcome Measure(s): We performed an isokinetic examination to evaluate the knee extensor (Ext) and flexor (Fl) concentric peak torque at 60°·s−1 and 240°·s−1 and (Fl only) eccentric peak torque at 30°·s−1 and 120°·s−1. Functional evaluation included countermovement jump, countermovement jump with arms, 10-m sprint, single-leg drop jump, and single-leg, 10-second continuous jumping. Variables were compared among groups using analysis of variance or a generalized linear mixed model for bilateral variables. Results: The 2 groups of basketball players demonstrated better isokinetic and functional performances than the control group did. No differences in functional or relative isokinetic variables were noted between professional and junior basketball players. Professional players with a history of knee injury failed to reach normal knee extensor strength at 60°·s−1. Knee Ext (60°·s−1) and Fl (eccentric 120°·s−1) torque values as well as 10-second continuous jumping scores were higher in those professional players without a history of knee injury than those with such a history. Compared with the group without a history of knee injury, the group with a history of knee injury maintained leg asymmetry ratios greater than 10% for almost all isokinetic variables and more than 15% for unilateral functional variables. Conclusions: The relative isokinetic and functional performances of professional basketball players were similar to those of junior

  2. Measurement of the Atmospheric $\

    CERN Document Server

    Aartsen, M G; Abdou, Y; Ackermann, M; Adams, J; Aguilar, J A; Ahlers, M; Altmann, D; Andeen, K; Auffenberg, J; Bai, X; Baker, M; Barwick, S W; Baum, V; Bay, R; Beattie, K; Beatty, J J; Bechet, S; Tjus, J Becker; Becker, K -H; Bell, M; Benabderrahmane, M L; BenZvi, S; Berdermann, J; Berghaus, P; Berley, D; Bernardini, E; Bertrand, D; Besson, D Z; Bindig, D; Bissok, M; Blaufuss, E; Blumenthal, J; Boersma, D J; Bohaichuk, S; Bohm, C; Bose1, D; Boser, S; Botner, O; Brayeur, L; Brown, A M; Bruijn, R; Brunner, J; Buitink, S; Carson, M; Casey, J; Casier, M; Chirkin, D; Christy, B; Clark, K; Clevermann, F; Cohen, S; Cowen, D F; Silva, A H Cruz; Danninger, M; Daughhetee, J; Davis, J C; De Clercq, C; De Ridder, S; Descamps, F; Desiati, P; de Vries-Uiterweerd, G; DeYoung, T; Diaz-Velez, J C; Dreyer, J; Dumm, J P; Dunkman, M; Eagan, R; Eberhardt, B; Eisch, J; Ellsworth, R W; Engdegard, O; Euler, S; Evenson, P A; Fadiran, O; Fazely, A R; Fedynitch, A; Feintzeig, J; Feusels, T; Filimonov, K; Finley, C; Fischer-Wasels, T; Flis, S; Franckowiak, A; Franke, R; Frantzen, K; Fuchs, T; Gaisser, T K; Gallagher, J; Gerhardt, L; Gladstone, L; Glusenkamp, T; Goldschmidt, A; Golup, G; Goodman, J A; Gora, D; Grant, D; Gross, A; Grullon, S; Gurtner, M; Ha, C; Ismail, A Haj; Hallgren, A; Halzen, F; Hanson, K; Heereman, D; Heimann, P; Heinen, D; Helbing, K; Hellauer, R; Hickford, S; Hill, G C; Hoffman, K D; Hoffmann, R; Homeier, A; Hoshina, K; Huelsnitz, W; Hulth, P O; Hultqvist, K; Hussain, S; Ishihara, A; Jacobi, E; Jacobsen, J; Japaridze, G S; Jlelati, O; Kappes, A; Karg, T; Karle, A; Kiryluk, J; Kislat, F; Klas, J; Klein, S R; Kohne, J -H; Kohnen, G; Kolanoski, H; Kopke, L; Kopper, C; Kopper, S; Koskinen, D J; Kowalski, M; Krasberg, M; Kroll, G; Kunnen, J; Kurahashi, N; Kuwabara, T; Labare, M; Landsman, H; Larson, M J; Lauer, R; Lesiak-Bzdak, M; Lunemann, J; Madsen, J; Maruyama, R; Mase, K; Matis, H S; McNally, F; Meagher, K; Merck, M; Meszaros, P; Meures, T; Miarecki, S; Middell, E; Milke, N; Miller, J; Mohrmann, L; Montaruli, T; Morse, R; Nahnhauer, R; Naumann, U; Nowicki, S C; Nygren, D R; Obertacke, A; Odrowski, S; Olivas, A; Olivo, M; O'Murchadha, A; Panknin, S; Paul, L; Pepper, J A; Heros, C Perez de los; Pieloth, D; Pirk, N; Posselt, J; Price, P B; Przybylski, G T; Radel, L; Rawlins, K; Redl, P; Resconi, E; Rhode, W; Ribordy, M; Richman, M; Riedel, B; Rodrigues, J P; Rott, C; Ruhe, T; Ruzybayev, B; Ryckbosch, D; Saba, S M; Salameh, T; Sander, H -G; Santander, M; Sarkar, S; Schatto, K; Scheel, M; Scheriau, F; Schmidt, T; Schmitz, M; Schoenen, S; Schoneberg, S; Schonherr, L; Schonwald, A; Schukraft, A; Schulte, L; Schulz, O; Seckel, D; Seo, S H; Sestayo, Y; Seunarine, S; Sheremata, C; Smith, M W E; Soiron, M; Soldin, D; Spiczak, G M; Spiering, C; Stamatikos, M; Stanev, T; Stasik, A; Stezelberger, T; Stokstad, R G; Stoss, A; Strahler, E A; Strom, R; Sullivan, G W; Taavola, H; Taboada, I; Tamburro, A; Ter-Antonyan, S; Tilav, S; Toale, P A; Toscano, S; Usner, M; van der Drift, D; van Eijndhoven, N; Van Overloop, A; van Santen, J; Vehring, M; Voge1, M; Vraeghe, M; Walck, C; Waldenmaier, T; Wallraff, M; Walter, M; Wasserman, R; Weaver, Ch; Wendt, C; Westerhoff, S; Whitehorn, N; Wiebe, K; Wiebusch, C H; Williams, D R; Wissing, H; Wolf, M; Wood, T R; Woschnagg, K; Xu, C; Xu, D L; Xu, X W; Yanez, J P; Yodh, G; Yoshida, S; Zarzhitsky, P; Ziemann, J; Zierke, S; Zilles, A; Zoll, M


    We report the first observation in a high energy neutrino telescope of cascades induced by atmospheric electron neutrinos and by neutral current interactions of atmospheric neutrinos of all flavors. Using data recorded during the first year of operation of IceCube's DeepCore low energy extension, a sample of 1029 events is observed in 281 days of data. The number of observed cascades is $N_{\\rm cascade} = 496 \\pm 66 (stat.) \\pm 88(syst.)$ and the rest of the sample consists of residual backgrounds due to atmospheric muons and charged current interactions of atmospheric muon neutrinos. The flux of the atmospheric electron neutrinos is determined in the energy range between approximately 80 GeV and 6 TeV and is consistent with models of atmospheric neutrinos.

  3. Kamchatka and North Kurile Volcano Explosive Eruptions in 2015 and Danger to Aviation (United States)

    Girina, Olga; Melnikov, Dmitry; Manevich, Alexander; Demyanchuk, Yury; Nuzhdaev, Anton; Petrova, Elena


    There are 36 active volcanoes in the Kamchatka and North Kurile, and several of them are continuously active. In 2015, four of the Kamchatkan volcanoes (Sheveluch, Klyuchevskoy, Karymsky and Zhupanovsky) and two volcanoes of North Kurile (Alaid and Chikurachki) had strong and moderate explosive eruptions. Moderate gas-steam activity was observing of Bezymianny, Kizimen, Avachinsky, Koryaksky, Gorely, Mutnovsky and other volcanoes. Strong explosive eruptions of volcanoes are the most dangerous for aircraft because they can produce in a few hours or days to the atmosphere and the stratosphere till several cubic kilometers of volcanic ash and aerosols. Ash plumes and the clouds, depending on the power of the eruption, the strength and wind speed, can travel thousands of kilometers from the volcano for several days, remaining hazardous to aircraft, as the melting temperature of small particles of ash below the operating temperature of jet engines. The eruptive activity of Sheveluch volcano began since 1980 (growth of the lava dome) and is continuing at present. Strong explosive events of the volcano occurred in 2015: on 07, 12, and 15 January, 01, 17, and 28 February, 04, 08, 16, 21-22, and 26 March, 07 and 12 April: ash plumes rose up to 7-12 km a.s.l. and extended more 900 km to the different directions of the volcano. Ashfalls occurred at Ust'-Kamchatsk on 16 March, and Klyuchi on 30 October. Strong and moderate hot avalanches from the lava dome were observing more often in the second half of the year. Aviation color code of Sheveluch was Orange during the year. Activity of the volcano was dangerous to international and local aviation. Explosive-effusive eruption of Klyuchevskoy volcano lasted from 01 January till 24 March. Strombolian explosive volcanic activity began from 01 January, and on 08-09 January a lava flow was detected at the Apakhonchich chute on the southeastern flank of the volcano. Vulcanian activity of the volcano began from 10 January. Ashfalls

  4. 76 FR 32867 - Hazardous Materials: Requirements for Storage of Explosives During Transportation (United States)


    ... for explosives in commerce (27 CFR Part 555). National Fire Protection Association (NFPA) 498... attendance requirements for explosives stored during transportation by designating the National Fire... warning sign: DANGER NO SMOKING NEVER FIGHT EXPLOSIVE FIRES VEHICLES ON THIS SITE CONTAIN EXPLOSIVES CALL...

  5. Measures for the explosion protection for gas systems; Massnahmen des Explosionsschutzes fuer Gasanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Faber, Wolfgang [Thyssengas GmbH, Duisburg (Germany). Anlagentechnik Nord; Seemann, Albert [BG ETEM Berufsgenossenschaft Energie Textil Elektro Medienerzeugnisse, Koeln (Germany)


    In order to protect employees, technical and organizational measures for explosion protection have to be provided to gas plants with potentially explosive areas. These measures have to be documented in the explosion protection document in accordance with paragraph 6 section 1 of the regulation of industrial safety. The contribution under consideration presents an overview on the measures for explosion protection for gas systems.

  6. Quantitative risk analysis of gas explosions in tunnels; probability, effects, and consequences

    NARCIS (Netherlands)

    Weerheijm, J.; Voort, M.M. van der; Verreault, J.; Berg, A.C. van den


    Tunnel accidents with transports of combustible liquefied gases may lead to explosions. Depending on the substance involved this can be a Boiling Liquid Expanding Vapour Explosion (BLEVE), a Gas Expansion Explosion (GEE) or a gas explosion. Quantification of the risk of these scenarios is important

  7. Atmospheric Circulation of Exoplanets


    Showman, Adam P.; Cho, James Y-K.; Menou, Kristen


    We survey the basic principles of atmospheric dynamics relevant to explaining existing and future observations of exoplanets, both gas giant and terrestrial. Given the paucity of data on exoplanet atmospheres, our approach is to emphasize fundamental principles and insights gained from Solar-System studies that are likely to be generalizable to exoplanets. We begin by presenting the hierarchy of basic equations used in atmospheric dynamics, including the Navier-Stokes, primitive, shallow-wate...

  8. Mandarin peel wastes pretreatment with steam explosion for bioethanol production. (United States)

    Boluda-Aguilar, María; García-Vidal, Lidia; González-Castañeda, Fayiny Del Pilar; López-Gómez, Antonio


    The mandarin (Citrus reticulata L.) citrus peel wastes (MCPW) were studied for bioethanol production, obtaining also as co-products: d-limonene, galacturonic acid, and citrus pulp pellets (CPP). The steam explosion pretreatment was analysed at pilot plant level to decrease the hydrolytic enzymes requirements and to separate and recover the d-limonene. The effect of steam explosion on MCPW lignocellulosic composition was analyzed by means thermogravimetric analysis. The d-limonene contents and their influence on ethanol production have been also studied, while concentration of sugars, galacturonic acid and ethanol have been analysed to measure the saccharification and fermentation (HF and SSF) processes efficiency obtained by MCPW steam explosion pretreatment. Ethanol contents of 50-60L/1000kg raw MCPW can be obtained and CPP yields can be regulated by means the control of enzymes dose and the steam explosion pretreatment which can significantly reduce the enzymes requirements. Copyright 2009 Elsevier Ltd. All rights reserved.

  9. Corneoscleral Laceration and Ocular Burns Caused by Electronic Cigarette Explosions. (United States)

    Paley, Grace L; Echalier, Elizabeth; Eck, Thomas W; Hong, Augustine R; Farooq, Asim V; Gregory, Darren G; Lubniewski, Anthony J


    To report cases of acute globe rupture and bilateral corneal burns from electronic cigarette (EC) explosions. Case series. We describe a series of patients with corneal injury caused by EC explosions. Both patients suffered bilateral corneal burns and decreased visual acuity, and one patient sustained a unilateral corneoscleral laceration with prolapsed iris tissue and hyphema. A review of the scientific literature revealed no prior reported cases of ocular injury secondary to EC explosions; however, multiple media and government agency articles describe fires and explosions involving ECs, including at least 4 with ocular injuries. Given these cases and the number of recent media reports, ECs pose a significant public health risk. Users should be warned regarding the possibility of severe injury, including sight-threatening ocular injuries ranging from corneal burns to full-thickness corneoscleral laceration.

  10. Explosive bubbles in house prices? Evidence from the OECD countries

    DEFF Research Database (Denmark)

    Engsted, Tom; Hviid, Simon Juul; Pedersen, Thomas Quistgaard

    We conduct an econometric analysis of bubbles in housing markets in the OECD area, using quarterly OECD data for 18 countries from 1970 to 2013. We pay special attention to the explosive nature of bubbles and use econometric methods that explicitly allow for explosiveness. First, we apply...... the univariate right-tailed unit root test procedure of Phillips et al. (2012) on the individual countries price-rent ratio. Next, we use Engsted and Nielsen's (2012) co-explosive VAR framework to test for bubbles. We find evidence of explosiveness in many housing markets, thus supporting the bubble hypothesis....... However, we also find interesting differences in the conclusions across the two test procedures. We attribute these differences to how the two test procedures control for cointegration between house prices and rent....

  11. Uncertainty in Explosive Yields of Core-Collapse Supernovae (United States)

    Andrews, Sydney; Fryer, Chris; Even, Wesley P.; Jones, Samuel; Pignatari, Marco; NuGrid Collaboration


    The chemical composition of the ejecta from the violent explosions of massive stars has been vital for probing the nature of the explosions and their effect on galactic chemical evolution and universal chemical composition. The sensitivity of numerical explosive nucleosynthetic yields in core-collapse supernovae to several key parameters is examined in one dimension. This uncertainty study is applied to 15, 20, and 25 solar mass stars with different energy prescriptions for shock revival. The effects of the resolution of the temperature and density profiles run through the NuGrid nuclear network are explored, as well as the differences between large and small isotope networks for the initial conditions of the explosion calculations.

  12. On Possibility of Detonation Products Temperature Measurements of Emulsion Explosives

    Directory of Open Access Journals (Sweden)

    Silvestrov V. V.


    Full Text Available The new view on the structure of the radiance signal recorded by optical pyrometer and the preliminary results of brightness detonation temperature of the emulsion explosive are presented. The structure of an optical signal observed is typical for the heterogeneous explosives. First, there is the short temperature spike to 2500 ÷ 3300 K connecting with a formation of “hot spots” assembly that fire the matrix capable of exothermal reaction. Then the relaxation of radiance to equilibrium level is observed that corresponds to brightness temperature 1840 ÷ 2260 K of explosion products at detonation pressure 1 ÷ 11 GPa. Experimental results are compared with the calculations of other authors. The detonation temperature of the investigated explosive is measured for the first time.

  13. 49 CFR 173.60 - General packaging requirements for explosives. (United States)


    ... explosives must provide double protection against leakage, such as a screw cap secured in place with tape. (3... fixed to cradles or contained in crates or other suitable handling, storage or launching devices in such...

  14. Explosion Testing of a Polycarbonate Safe Haven Wall

    National Research Council Canada - National Science Library

    Kyle A. Perry; Rex A. Meyr


    ...) blast loading spanning 200 milliseconds. The successful design was constructed at a uniform height in both half-width scale and quarter-width scale in the University of Kentucky Explosives Research Team’s (UKERT...

  15. Benefits of explosive cutting for nuclear-facility applications

    Energy Technology Data Exchange (ETDEWEB)

    Hazelton, R.F.; Lundgren, R.A.; Allen, R.P.


    The study discussed in this report was a cost/benefit analysis to determine: (1) whether explosive cutting is cost effective in comparison with alternative metal sectioning methods and (2) whether explosive cutting would reduce radiation exposure or provide other benefits. Two separate approaches were pursued. The first was to qualitatively assess cutting methods and factors involved in typical sectioning cases and then compare the results for the cutting methods. The second was to prepare estimates of work schedules and potential radiation exposures for candidate sectioning methods for two hypothetical, but typical, sectioning tasks. The analysis shows that explosive cutting would be cost effective and would also reduce radiation exposure when used for typical nuclear facility sectioning tasks. These results indicate that explosive cutting should be one of the principal cutting methods considered whenever steel or similar metal structures or equipment in a nuclear facility are to be sectioned for repair or decommissioning. 13 figures, 7 tables. (DLC)

  16. Bias-corrected estimation in potentially mildly explosive autoregressive models

    DEFF Research Database (Denmark)

    Haufmann, Hendrik; Kruse, Robinson

    that the indirect inference approach oers a valuable alternative to other existing techniques. Its performance (measured by its bias and root mean squared error) is balanced and highly competitive across many different settings. A clear advantage is its applicability for mildly explosive processes. In an empirical...... application to a long annual US Debt/GDP series we consider rolling window estimation of autoregressive models. We find substantial evidence for time-varying persistence and periods of explosiveness during the Civil War and World War II. During the recent years, the series is nearly explosive again. Further......This paper provides a comprehensive Monte Carlo comparison of different finite-sample bias-correction methods for autoregressive processes. We consider classic situations where the process is either stationary or exhibits a unit root. Importantly, the case of mildly explosive behaviour is studied...

  17. Computer simulation of metal wire explosion under high rate heating (United States)

    Zolnikov, K. P.; Kryzhevich, D. S.; Korchuganov, A. V.


    Synchronous electric explosion of metal wires and synthesis of bicomponent nanoparticles were investigated on the base of molecular dynamics method. Copper and nickel nanosized crystallites of cylindrical shape were chosen as conductors for explosion. The embedded atom approximation was used for calculation of the interatomic interactions. The agglomeration process after explosion metal wires was the main mechanism for particle synthesis. The distribution of chemical elements was non-uniform over the cross section of the bicomponent particles. The copper concentration in the surface region was higher than in the bulk of the synthesized particle. By varying the loading parameters (heating temperature, the distance between the wires) one can control the size and internal structure of the synthesized bicomponent nanoparticles. The obtained results showed that the method of molecular dynamics can be effectively used to determine the optimal technological mode of nanoparticle synthesis on the base of electric explosion of metal wires.

  18. Terrorism and Drug Trafficking: Technologies for Detecting Explosives and Narcotics (United States)


    The General Accounting Office (GAO) examined information on explosives and narcotics detection technologies that are available or under development. This report discusses (1) funding for those technologies, (2) characteristics and limitations of avai...

  19. Detection of explosives based on surface-enhanced Raman spectroscopy. (United States)

    Wackerbarth, Hainer; Salb, Christian; Gundrum, Lars; Niederkrüger, Matthias; Christou, Konstantin; Beushausen, Volker; Viöl, Wolfgang


    In this study we present a device based on surface-enhanced Raman scattering (SERS) for the detection of airborne explosives. The explosives are resublimated on a cooled nanostructured gold substrate. The explosives trinitrotoluene (TNT) and triacetone triperoxide (TATP) are used. The SERS spectrum of the explosives is analyzed. Thus, TNT is deposited from an acetonitrile solution on the gold substrate. In the case of TATP, first the bulk TATP Raman spectrum was recorded and compared with the SERS spectrum, generated by deposition out of the gas phase. The frequencies of the SERS spectrum are hardly shifted compared to the spectrum of bulk TATP. The influence of the nanostructured gold substrate temperature on the signals of TATP was studied. A decrease in temperature up to 200 K increased the intensities of the TATP bands in the SERS spectrum; below 200 K, the TATP fingerprint disappeared.

  20. Nanoplasmonic imaging of latent fingerprints with explosive RDX residues. (United States)

    Peng, Tianhuan; Qin, Weiwei; Wang, Kun; Shi, Jiye; Fan, Chunhai; Li, Di


    Explosive detection is a critical element in preventing terrorist attacks, especially in crowded and influential areas. It is probably more important to establish the connection of explosive loading with a carrier's personal identity. In the present work, we introduce fingerprinting as physical personal identification and develop a nondestructive nanoplasmonic method for the imaging of latent fingerprints. We further integrate the nanoplasmonic response of catalytic growth of Au NPs with NADH-mediated reduction of 1,3,5-trinitro-1,3,5-triazinane (RDX) for the quantitative analysis of RDX explosive residues in latent fingerprints. This generic nanoplasmonic strategy is expected to be used in forensic investigation to distinguish terrorists that carry explosives.

  1. Contributed review: quantum cascade laser based photoacoustic detection of explosives. (United States)

    Li, J S; Yu, B; Fischer, H; Chen, W; Yalin, A P


    Detecting trace explosives and explosive-related compounds has recently become a topic of utmost importance for increasing public security around the world. A wide variety of detection methods and an even wider range of physical chemistry issues are involved in this very challenging area. Optical sensing methods, in particular mid-infrared spectrometry techniques, have a great potential to become a more desirable tools for the detection of explosives. The small size, simplicity, high output power, long-term reliability make external cavity quantum cascade lasers (EC-QCLs) the promising spectroscopic sources for developing analytical instrumentation. This work reviews the current technical progress in EC-QCL-based photoacoustic spectroscopy for explosives detection. The potential for both close-contact and standoff configurations using this technique is completely presented over the course of approximately the last one decade.


    Directory of Open Access Journals (Sweden)

    M. I. Baranov


    Full Text Available Purpose. Obtaining approximate calculation correlations for determination of maximal values of temperature Tm, and pressures Pm at a shock wave and speed vm distribution of a shock wave in the plasma products of air electric explosion (EE of metall conductor under act of large impulsive current (LIC. Methodology. Theoretical bases of the electrical engineering, scientific and technical bases of electrophysics, thermal physics and electrophysics bases of powerful high-voltage impulse technique, related to the theory and practice of the phenomenon EE metallic explorer in gas environments under action of LIC. Results. New calculation correlations are got for approximate calculation in a local area of EE in atmospheric air of metallic explorer of maximal values of temperature Tm,, pressures Pm and speeds of vm of shock wave in «metallic plasma» appearing from an explosion under action of LIC of its conducting structure. It is set that numeral values of the sought after sizes of temperature Tm,, pressures Pm and speeds vm as it applies to air EE thin copper conductor under the action of LIC of the microsecond temporal range can arrive at a few ten of thousands of Kelvin, hundreds of technical atmospheres and thousands of meters in a second accordingly. It is shown that similar values of speed vm of shock wave in «metallic plasma» are comparable at speed of detonation wave in hard explosives. An accent is in this connection done on expedience of application air EE thin short metallic conductors at injury of live ammunitions with an ordinary and nuclear explosive. The real technical suggestions are offered on a possible receipt in the discharge circuit of powerful high-voltage generator of LIC of condenser type of «record» (most values of the examined descriptions of «metallic plasma» at air EE thin metallic conductors. Comparison of the obtained results is executed for the probed descriptions of plasma at air EE of the metal conductor with

  3. Designing Dynamic Atmospheres

    DEFF Research Database (Denmark)

    Kinch, Sofie; Højlund, Marie


    This paper addresses the notion of atmospheres from a designerly perspective, and discusses temporal challenges facing interaction designers when acknowledging the dynamic character of it. As atmospheres are created in the relation between body, space, and time, a pragmatic approach seems useful,....... The potentials and implica-­‐ tions are presented through a design case, Kidkit, highlighting temporality as design parametre within interaction design.......This paper addresses the notion of atmospheres from a designerly perspective, and discusses temporal challenges facing interaction designers when acknowledging the dynamic character of it. As atmospheres are created in the relation between body, space, and time, a pragmatic approach seems useful...

  4. Atmospheric Measurements Laboratory (AML) (United States)

    Federal Laboratory Consortium — The Atmospheric Measurements Laboratory (AML) is one of the nation's leading research facilities for understanding aerosols, clouds, and their interactions. The AML...

  5. A false explosion for a real intervention

    CERN Multimedia


    Together with their French and Swiss counterparts, the CERN Fire Brigade carried out a spectacular exercise in the LHCb cavern. It was designed to test the coordination of the fire and rescue services of the Organization's two Host States. Inside a temporary medical station set up above ground, the emergency teams deliver medical care to the injured before they are taken to hospital.An accident victim in the underground cavern about to be evacuated. 'I was taking a group of visitors on a tour of the LHCb cavern when there was a huge explosion and I suffered serious burns to the thorax. The rescue services arrived on the scene and I was taken to the medical station'. Fortunately, this is not an account of real events but a scenario given to one of 20 volunteer 'victims' who took part in a large-scale safety exercise in the LHCb cavern. On 26 September, the CERN Fire Brigade organised a spectacular exercise in collaboration with the CERN Medical Service, the Fire and Rescue Service (SDIS) of the Department of t...

  6. Novel methods for detecting buried explosive devices

    Energy Technology Data Exchange (ETDEWEB)

    Kercel, S.W.; Burlage, R.S.; Patek, D.R.; Smith, C.M. [Oak Ridge National Lab., TN (United States); Hibbs, A.D.; Rayner, T.J. [Quantum Magnetics, Inc., San Diego, CA (United States)


    Oak Ridge National Laboratory (ORNL) and Quantum Magnetics, Inc. (QM) are exploring novel landmine detection technologies. Technologies considered here include bioreporter bacteria, swept acoustic resonance, nuclear quadrupole resonance (NQR), and semiotic data fusion. Bioreporter bacteria look promising for third-world humanitarian applications; they are inexpensive, and deployment does not require high-tech methods. Swept acoustic resonance may be a useful adjunct to magnetometers in humanitarian demining. For military demining, NQR is a promising method for detecting explosive substances; of 50,000 substances that have been tested, none has an NQR signature that can be mistaken for RDX or TNT. For both military and commercial demining, sensor fusion entails two daunting tasks, identifying fusible features in both present-day and emerging technologies, and devising a fusion algorithm that runs in real-time on cheap hardware. Preliminary research in these areas is encouraging. A bioreporter bacterium for TNT detection is under development. Investigation has just started in swept acoustic resonance as an approach to a cheap mine detector for humanitarian use. Real-time wavelet processing appears to be a key to extending NQR bomb detection into mine detection, including TNT-based mines. Recent discoveries in semiotics may be the breakthrough that will lead to a robust fused detection scheme.

  7. Explosive electron emission from flat Ge crystals

    Energy Technology Data Exchange (ETDEWEB)

    Porshyn, Vitali; Mingels, Stephan; Luetzenkirchen-Hecht, Dirk; Mueller, Guenter [University of Wuppertal (Germany)


    During the search for photo-induced field emission from flat semiconductors, which might provide high brightness electron beams, we have found with our new ultra-high vacuum measurement system explosive electron emission (EEE) from n-doped Ge crystals resulting in high current pulses of ∝100 A and ∝4 ns duration. This effect reproducibly appears in a narrow photon energy range of 3.2-3.6 eV with a quantum efficiency of up to 20%. Moreover, the EEE current does not depend on the surface field but on the extraction voltage (500-3000 V). EEE is a well known plasma-induced effect for locally heated metals resulting in a crater-like destruction of the surface. For Ge, however, it appears at a factor of 20 lower power density (0.3 MW/cm{sup 2}) of the pulsed laser, and each current pulse forms a new crater of ∝10 μm size. The measured EEE spectra show a similar FWHM (< 1 eV) as photo emitted electrons. Potential applications, e.g. in microwave tubes or gyrotrons, will be discussed.

  8. 'Home Plate' Evidence for an Explosive Past (United States)


    This view of layers around the edge of a low plateau called 'Home Plate' inside Mars' Gusev Crater includes a feature that may be what geologists call a 'bomb sag' and interpret as evidence of an explosive event, such as a volcanic eruption. The layers seen here are generally straight and parallel except in the lower right, where they dip around a greyish rock that is about 4 centimeters (about 1.5 inches) in diameter. When layered deposits are struck by a falling rock while the layers are still soft, this type of pattern can be created. The rock might have been lofted by a volcanic burst or as part of the material ejected by the crater-forming impact of a meteorite. The panoramic camera (Pancam) on NASA's Mars Exploration Rover Spirit acquired the exposures for this image on Spirit's 754th Martian day (Feb. 15, 2006). This view is an approximately true-color rendering mathematically generated from separate images taken through all of the left Pancam's 432-nanometer to 753-nanometer filters.

  9. Novel methods for detecting buried explosive devices (United States)

    Kercel, Stephen W.; Burlage, Robert S.; Patek, David R.; Smith, Cyrus M.; Hibbs, Andrew D.; Rayner, Timothy J.


    Oak Ridge National Laboratory and Quantum Magnetics, Inc. are exploring novel landmine detection technologies. Technologies considered here include bioreporter bacteria, swept acoustic resonance, nuclear quadrupole resonance (NQR), and semiotic data fusion. Bioreporter bacteria look promising for third-world humanitarian applications; they are inexpensive, and deployment does not require high-tech methods. Swept acoustic resonance may be a useful adjunct to magnetometers in humanitarian demining. For military demining, NQR is a promising method for detecting explosive substances; of 50,000 substances that have been tested, one has an NQR signature that can be mistaken for RDX or TNT. For both military and commercial demining, sensor fusion entails two daunting tasks, identifying fusible features in both present-day and emerging technologies, and devising a fusion algorithm that runs in real-time on cheap hardware. Preliminary research in these areas is encouraging. A bioreporter bacterium for TNT detection is under development. Investigation has just started in swept acoustic resonance as an approach to a cheap mine detector for humanitarian use. Real-time wavelet processing appears to be a key to extending NQR bomb detection into mine detection, including TNT-based mines. Recent discoveries in semiotics may be the breakthrough that will lead to a robust fused detection scheme.

  10. Photocatalytic degradation of explosives contaminated water. (United States)

    Lee, S J; Son, H S; Lee, H K; Zoh, K D


    This study was undertaken to examine the degradation of TNT, RDX and HMX in a circular photocatalytic reactor with TiO2 as a photocatalyst. We examined the impact of parameters such as the initial concentration, initial pH of solution on rates of photocatalized transformation, and the mineralization. The results showed that photocatalysis is an effective process for the degradation of TNT, RDX and HMX. They could be comoletely degraded in 150 min with 1.0 g/L TiO2 at pH 7. An increase in the photocatalytic degradation of HMX was noticed with decreasing initial HMX. The rates of RDX and HMX degradation were greater in neutral pH than in acidic and alkaline conditions. In case of TNT degradation, the rate of degradation was the fastest at pH 11. Approximately 82% TOC decrease in the TNT degradation was achieved after 150 min, whereas TOC decrease in RDX and HMX was 24% and 59%, respectively. Nitrate, nitrite, and ammonium ions were detected as the nitrogen byproducts from the photocatalysis, and more than 50% of the total nitrogen was recovered as nitrate ion in every explosives.

  11. Mechanistic Reactive Burn Modeling of Solid Explosives

    Energy Technology Data Exchange (ETDEWEB)

    Y.Horie; Y.Hamate; D.Greening


    This report describes a computational framework for reactive burn modeling of solid explosives and the development of a test case where physical mechanisms represent RDX or RDX-based materials. The report is a sequel to LA-13794-MS, ''A Unifying Framework for Hot Spots and the Ignition of Energetic Materials,'' where we proposed a new approach to the building of a general purpose model that captures the essential features of the three primary origins of hot-spot formation: void collapse, shear banding, friction. The purpose of the present report is to describe the continuing task of coupling the unifying hot-spot model to hydrodynamic calculations to develop a mechanistic reactive burn model. The key components of the coupling include energy localization, the growth of hot spots, overall hot-spot behavior, and a phase-averaged mixture equation of state (EOS) in a Mie-Grueneisen form. The nucleation and growth of locally heated regions is modeled by a phenomenological treatment as well as a statistical model based on an exponential size distribution. The Mie-Grueneisen form of the EOS is one of many possible choices and is not a critical selection for implementing the model. In this report, model calculations are limited to proof-of-concept illustrations for shock loading. Results include (1) shock ignition and growth-to-detonation, (2) double shock ignition, and (3) quenching and reignition. A comparative study of Pop-plots is discussed based on the statistical model.

  12. Color camera pyrometry for high explosive detonations (United States)

    Densmore, John; Biss, Matthew; Homan, Barrie; McNesby, Kevin


    Temperature measurements of high-explosive and combustion processes are difficult because of the speed and environment of the events. We have characterized and calibrated a digital high-speed color camera that may be used as an optical pyrometer to overcome these challenges. The camera provides both high temporal and spatial resolution. The color filter array of the sensor uses three color filters to measure the spectral distribution of the imaged light. A two-color ratio method is used to calculate a temperature using the color filter array raw image data and a gray-body assumption. If the raw image data is not available, temperatures may be calculated from processed images or movies depending on proper analysis of the digital color imaging pipeline. We analyze three transformations within the pipeline (demosaicing, white balance, and gamma-correction) to determine their effect on the calculated temperature. Using this technique with a Vision Research Phantom color camera, we have measured the temperature of exploded C-4 charges. The surface temperature of the resulting fireball rapidly increases after detonation and then decayed to a constant value of approximately 1980 K. Processed images indicates that the temperature remains constant until the light intensity decreased below the background value.

  13. Photoluminescent Detection of Dissolved Underwater Trace Explosives

    Directory of Open Access Journals (Sweden)

    Tye Langston


    Full Text Available A portable, rapid, and economical method for in situ trace explosive detection in aqueous solutions was demonstrated using photoluminescence. Using europium/thenoyltrifluoroacetone as the reagent, dissolved nitroglycerin was fluorescently tagged and detected in seawater solutions without sample preparation, drying, or preconcentration. The chemical method was developed in a laboratory setting and demonstrated in a flow-through configuration using lightweight, inexpensive, commercial components by directly injecting the reagents into a continually flowing seawater stream using a small amount of organic solvent (approximately 8% of the total solution. Europium's vulnerability to vibrational fluorescence quenching by water provided the mode of detection. Without nitroglycerin in the seawater solution, the reagent's fluorescence was quenched, but when dissolved nitroglycerin was present, it displaced the water molecules from the europium/thenoyltrifluoroacetone compound and restored fluorescence. This effort focused on developing a seawater sensor, but performance comparisons were made to freshwater. The method was found to perform better in freshwater and it was shown that certain seawater constituents (such as calcium have an adverse impact. However, the concentrations of these constituents are not expected to vary significantly from the natural seawater used herein.

  14. Multispectral Observations of Explosive Gas Emissions from Santiaguito, Guatemala (United States)

    Carn, S. A.; Watson, M.; Thomas, H.; Rodriguez, L. A.; Campion, R.; Prata, F. J.


    Santiaguito volcano, Guatemala, has been persistently active for decades, producing frequent explosions from its actively growing lava dome. Repeated release of volcanic gases contains information about conduit processes during the cyclical explosions at Santiaguito, but the composition of the gas phase and the amount of volatiles released in each explosion remains poorly constrained. In addition to its persistent activity, Santiaguito offers an exceptional opportunity to investigate lava dome degassing processes since the upper surface of the active lava dome can be viewed from the summit of neighboring Santa Maria. In January 2016 we conducted multi-spectral observations of Santiaguito's explosive eruption plumes and passive degassing from multiple perspectives as part of the first NSF-sponsored `Workshop on Volcanoes' instrument deployment. Gas measurements included open-path Fourier-Transform infrared (OP-FTIR) spectroscopy from the Santa Maria summit, coincident with ultraviolet (UV) and infrared (IR) camera and UV Differential Optical Absorption Spectroscopy (DOAS) from the El Mirador site below Santiaguito's active Caliente lava dome. Using the OP-FTIR in passive mode with the Caliente lava dome as the source of IR radiation, we were able to collect IR spectra at high temporal resolution prior to and during two explosions of Santiaguito on 7-8 January, with volcanic SO2 and H2O emissions detected. UV and IR camera data provide constraints on the total SO2 burden in the emissions (and potentially the volcanic ash burden), which coupled with the FTIR gas ratios provides new constraints on the mass and composition of volatiles driving explosions at Santiaguito. All gas measurements indicate significant volatile release during explosions with limited degassing during repose periods. In this presentation we will present ongoing analysis of the unique Santiaguito gas dataset including estimation of the total volatile mass released in explosions and an

  15. Photographic Study Of A Dead-Pressed Explosive (United States)

    Swallowe, G. M.; Field, J. E.


    High speed photography in conjunction with electron microscopy and a pressure measuring technique have been used to investigate the differences between dead-pressed and non-dead-pressed samples of the primary explosive Mercury Fulminate (Hg Ful). Photographs of reaction propagation were taken in transmitted light using a specially adapted drop-weight machine with transparent anvils. The results of these experiments suggested a mechanism for dead-pressing in Hg Ful based on the microscopic internal structure of the compacted explosive.

  16. Szilard Prize Lecture: Seismic Monitoring of Nuclear Explosions (United States)

    Richards, Paul


    Seismic monitoring of the more than 2000 nuclear test explosions since 1945 has been vigorously pursued, both to track the weapons development of potential adversaries, and to support initiatives in nuclear arms control, including various test ban treaties. Major funding from the US Department of Defense built up new global seismographic networks and over several decades established practical capability in monitoring nuclear explosions ``teleseismically'' (i.e. from distances more than about 1500 km), for tests that the testing nation did not attempt to conceal. What then is the capability to monitor compliance with, for example, the Comprehensive Nuclear-Test-Ban Treaty (CTBT) of 1996, particularly if evasion scenarios are considered? Note that the CTBT, though not ratified by some countries (including the US), is now being monitored by networks that include seismographic stations at ``regional'' distances (< 1500 km) from candidate explosion locations. Years of R and D have shown that regional signals can be used to monitor down to yields significantly lower than can be detected and identified teleseismically. A US National Academy of Sciences study in 2002 concluded that ``an underground nuclear explosion cannot be confidently hidden if its yield is larger than 1 or 2 kt.'' About 1000 earthquakes and chemical explosions are now detected per day, and documented via seismic data, providing plenty of challenges for nuclear explosion monitoring organizations. Explosion monitoring capability will improve in many parts of the world, due to the growth of networks that monitor even small earthquakes to study seismic hazard. But political problems can impede improved international explosion monitoring, due to national restrictions on data access.

  17. Encyclopedia of Explosives and Related Items. Volume 9 (United States)


    CondChemDict (1977), 749 TM 9-1300-206 (1964) Resina Explosiva (Span). (Rgsine explosible or Requa Battery. A .58 cal weapon developed in Vixorite in Fr). An...chambers for appreciable periods before firing Findings that cavities such as bubbles, inci- Sevranites. Fr plastic explosives developed in dental to...ob- by the impact served with Cyclotol 75/25. Octol 75/25 should be considered as rather difficult to ignite acci- 100 dentally by mechanical means but

  18. Application of paper spray ionization for explosives analysis. (United States)

    Tsai, Chia-Wei; Tipple, Christopher A; Yost, Richard A


    A desired feature in the analysis of explosives is to decrease the time of the entire analysis procedure, including sampling. A recently utilized ambient ionization technique, paper spray ionization (PSI), provides the possibility of combining sampling and ionization. However, an interesting phenomenon that occurs in generating negatively charged ions pose some challenges in applying PSI to explosives analysis. The goal of this work is to investigate the possible solutions for generating explosives ions in negative mode PSI. The analysis of 2,4,6-trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), and 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) was performed. Several solvent systems with different surface tensions and additives were compared to determine their effect on the ionization of explosives. The solvents tested include tert-butanol, isopropanol, methanol, and acetonitrile. The additives tested were carbon tetrachloride and ammonium nitrate. Of the solvents tested, isopropanol yielded the best results. In addition, adding ammonium nitrate to the isopropanol enhanced the analyte signal. Experimentally determined limits of detection (LODs) as low as 0.06 ng for PETN, on paper, were observed with isopropanol and the addition of 0.4 mM ammonium nitrate as the spray solution. In addition, the explosive components of two plastic explosive samples, Composition 4 and Semtex, were successfully analyzed via surface sampling when using the developed method. The analysis of explosives using PSI-MS in negative ion mode was achieved. The addition of ammonium nitrate to isopropanol, in general, enhanced the analyte signal and yielded better ionization stability. Real-world explosive samples were analyzed, which demonstrates one of the potential applications of PSI-MS analysis. Copyright © 2017 John Wiley & Sons, Ltd.





    ABSTRACT : BACKGROUND: Though homicide, in general seems universal, the type and pattern are specific to particular societies and particular times. OBJECTIVE : Medicolegal study of homicide by firearms and explosives. METHODS: The present study comprised of 100 (one hundred) cases of homicidal firearms and explosives deaths drawn from the medicolegal autopsies held in the mortuary of the department of Forensic Medicine accompanied by sufficient number of...

  20. Orbital Characteristics of Binary Systems after Asymmetric Supernova Explosions


    Kalogera, Vassiliki


    We present an analytical method for studying the changes of the orbital characteristics of binary systems with circular orbits due to a kick velocity imparted to the newborn neutron star during a supernova explosion (SN). Assuming a Maxwellian distribution of kick velocities we derive analytical expressions for the distribution functions of orbital separations and eccentricities immediately after the explosion, of orbital separations after circularization of the post-SN orbits, and of systemi...