WorldWideScience

Sample records for atmospheric explosions

  1. Phenomenology of atmospheric, submarine and underground explosions

    International Nuclear Information System (INIS)

    An atmospheric nuclear explosion, particularly at ground level or at low altitude, generates immediate radiation that is propagated via different modes of energy transfer, i.e.: electromagnetic waves, light and heat, mechanical effects. Late-stage phenomena, such as the formation and propagation of the cloud, follow on after these early effects. The whole range of different effects - including acoustic and seismic waves as well as the products contained in the cloud - can be detected at distances up to several hundred or several thousand km. When the nuclear source is submarine, a shock wave is generated due to the interaction with the medium. According to the depth of the source, a gas bubble is created which starts to pulsate. As a result of this effect, the acoustic signal is modulated and then propagated to great distances away from the source, thus enabling identification of the explosive phenomenon in the water column. In the case of underground explosions, it is possible to establish a complete description of the interaction with the medium. This comprises generation and propagation of the shock wave, creation of the cavity, zonation of explosion effects, vent collapse, etc. The influence of depth on crater formation, subsidence and decoupling is also discussed. (authors)

  2. Detection of nuclear explosions in the atmosphere

    International Nuclear Information System (INIS)

    Atmospheric nuclear explosions can be detected at great distances owing to the electromagnetic, optical and acoustic effects that are produced, in addition to the emission of radioactive gases, particles and/or radionuclides into the atmosphere. The optical effects are the first to be detected. Sub-audible pressure waves (infra-sound) are propagated over considerable distances at the speed of sound, the temperature gradients within the atmosphere acting as wave guides. Thus, although infra-sound effects are picked up at a much later stage, their signatures remain characteristic up to distances of one thousand or a few thousand km depending on the source yield and the wind direction. The bearing of the source and the velocity of infra-sound waves can be determined by conventional methods. Since radionuclides are carried by winds over very large distances, radioactivity measurements represent late-stage but extremely sensitive technique for detecting explosions in the atmosphere. In fact, current arrangements for sampling and measurement are highly efficient, making it possible to attain very low detection limits. Otherwise, characterization of the different radionuclides that may be released can provide information enabling a discrimination between nuclear tests and accidents/incidents at nuclear power. Furthermore, calculation/incidents at nuclear power plants. Furthermore, calculation codes may be used to evaluate the location and approximate date of origin of the event. (authors)

  3. Influence of Atmospheric Nuclear Explosions on Climate Change

    OpenAIRE

    Fujii, Yoshiaki

    2010-01-01

    This article suggests that the 0.5K stagnation in the global-mean surface temperature (GST) between 1945 and 1976 would be due to the atmospheric nuclear explosions, namely, Gadget, Little Boy, Fat Man and the succeeding at least 422 times nuclear weapons testing between 1946 and 1980. Estimation on GST drop due to the atmospheric nuclear explosions based on the published numerical simulation results was at least between 0.07K and 0.8K. The 0.5K GST stagnation was in the range of the estimati...

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

    CERN Document Server

    Jespen, Torben

    2016-01-01

    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.

  5. North Atlantic explosive cyclones and large scale atmospheric variability modes

    Science.gov (United States)

    Liberato, Margarida L. R.

    2015-04-01

    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

  6. A Study on intelligent measurement of nuclear explosion equivalent in atmosphere

    International Nuclear Information System (INIS)

    Measurement of nuclear explosion equivalent in atmosphere is an important subject for nuclear survey. Based on the relations between nuclear explosion equivalent and the minimum illuminance time of light radiation from nuclear explosion. The method of RC differential valley time detection and mean-time taking is presented the method, using a single-chip computer as a intelligent part, can realize intelligent measurement of minimum illuminance time with high reliability and low power consumption. This method provides a practical mean for quick, accurate and reliable measurement of nuclear explosion equivalent in atmosphere

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

    Directory of Open Access Journals (Sweden)

    Niculae Serban Costin

    2014-09-01

    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. Lithosphere-atmosphere-ionosphere coupling after the 2003 explosive eruption of the Soufriere Hills Volcano, Montserrat

    Science.gov (United States)

    Dautermann, Thomas; Calais, Eric; Lognonné, Philippe; Mattioli, Glen S.

    2009-12-01

    Resonant coupling between the Earth and the atmosphere at frequencies where the solid Earth modes overlap the fundamental modes of the atmosphere allows for the triggering of oscillatory acoustic perturbations by ground excitation and vice versa. Here, we describe oscillatory perturbations observed in the solid Earth (from volumetric borehole strainmeter data) and in the atmosphere (from GPS-derived ionospheric total electron content) following the 2003 July 13, Soufrière Hills Volcano explosion (Montserrat, Lesser Antilles). Spectral analysis shows an amplitude peak at 4 mHz for both data sets, with similar waveforms and signal duration. Using a normal mode summation technique, we show that both signals are explained by a single explosive source in the atmosphere. Similarities in waveforms, in particular a double wave train also reported after several other explosion-triggered atmospheric perturbations, result from the superposition of the dominant (fundamental) atmospheric modes that trigger resonant coupling with the solid Earth around 4 mHz.

  9. The acoustic field in the atmosphere and ionosphere caused by a point explosion on the ground

    Science.gov (United States)

    Drobzheva, Ya. V.; Krasnov, V. M.

    2003-02-01

    In this paper, we present a set of equations and their solutions which describe the propagation of acoustic pulses through a model terrestrial atmosphere due to a chemical explosion on the ground, and the effects of these pulses on the ionosphere above the explosion. Our calculations appear to agree remarkably well with acoustic and radio sounding data measured for the 1981 Mill Race explosion at seven different altitudes from approximately /10-260km. We show that (i) the acoustic wave speed depends on the viscosity and thermal conductivity of the atmosphere, (ii) the amplitude of the fluid velocity in the acoustic wave reaches a maximum at an altitude of about 120km, (iii) the altitude of the maximum does not depend on the initial launch angle of the acoustic wavefront or the size of the explosion, and (iv) the path taken by different parts of the acoustic wavefront depends on the yield of explosion.

  10. Atmospheric sampling glow discharge ionizataion and triple quadrupole tandem mass spectrometry for explosives vapor detection

    Energy Technology Data Exchange (ETDEWEB)

    McLuckey, S.A.; Goeringer, D.E.; Asano, K.G.; Hart, K.J.; Glish, G.L.; Grant, B.C.; Chambers, D.M.

    1993-08-01

    The detection and identification of trace vapors of hidden high explosives is an excellent example of a targeted analysis problem. It is desirable to push to ever lower levels the quantity or concentration of explosives material that provides an analytical signal, while at the same time discriminating against all other uninteresting material. The detection system must therefore combine high sensitivity with high specificity. This report describes the philosophy behind the use of atmospheric sampling glow discharge ionization, which is a sensitive, rugged, and convenient means for forming anions from explosives molecules, with tandem mass spectrometry, which provides unparalleled specificity in the identification of explosives-related ions. Forms of tandem mass spectrometry are compared and contrasted to provide a summary of the characteristics to be expected from an explosives detector employing mass spectrometry/mass spectrometry. The instrument developed for the FAA, an atmospheric sampling glow discharge/triple quadrupole mass spectrometer, is described in detail with particular emphasis on the ion source/spectrometer interface and on the capabilities of the spectrometer. Performance characteristics of the system are also described as they pertain to explosives of interest including a description of an automated procedure for the detection and identification of specific explosives. A comparison of various tandem mass spectrometers mated with atmospheric sampling glow discharge is then described and preliminary studies with a vapor preconcentration system provided by the FAA will be described.

  11. Bursts of electromagnetic EHF noise in the upper atmosphere induced by surface explosions

    International Nuclear Information System (INIS)

    Analysis of data of wave electromagnetic observations in OGO-6 satellite shows the occurrence of localized bursts of magnetic component intensity at frequencies of the order of 10 Hz, when flying over the points of surface explosions. The revealed effect can be related with high penetration of atmospheric radiation into the upper ionosphere in the region, disturbed by acoustic wave of explosion. 16 refs., 2 figs

  12. Characteristics of acoustic wave from atmospheric nuclear explosions conducted at the USSR Test Sites

    Science.gov (United States)

    Sokolova, Inna

    2015-04-01

    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

  13. 'Bromine and Chlorine Explosion' in a Simulated Atmosphere

    OpenAIRE

    Buxmann, Joelle Caroline Elisabeth

    2012-01-01

    Als Brom und Chlor 'Explosion' (BE und CE) bezeichnet man die autokatalytische, heterogene Freisetzung von reaktiven Halogenverbindungen (RHV). Bei der Zerstörung von atmosphärischem Ozon und der Beeinflussung der HOx und NOx Chemie, spielen die RHV BrO und ClO eine grosse Rolle. In dieser Arbeit werden die ersten direkten Messungen des BrO aus der BE über einer künstlichen Salzpfanne in einer Smogkammer unter troposphärischer Lichteinstrahlung gezeigt. Zudem wurden ClO, OClO (aus der CE) und...

  14. A re-analysis of the atmospheric and ionospheric effects of the Flixborough explosion

    Science.gov (United States)

    Krasnov, V. M.; Drobzheva, Ya. V.; Venart, J. E. S.; Lastovicka, J.

    2003-07-01

    The ionospheric record of the 1974 cyclohexane vapour cloud explosion (VCE) accident near Flixborough is re-examined in light of a new theory used to describe the acoustic field in the atmosphere and ionosphere caused by explosions on the ground. The reconstructed oblique Doppler sounding records from six radio traces agree remarkably well with experimental results when a ground source explosion yield of 283+/-38tons of TNT is utilized. This result, when compared to the detonation of large hydrocarbon fuel-drop-air clouds, suggests that only 14+/-2tons of cyclohexane was involved in the explosion. Additionally the time of the explosion determined from the model, 15:52:08+/-6, agrees, within the mutual uncertainty, with that determined seismically, 15:52:15.5+/-2 UT. The precision in the value of the yield and accuracy of the time of the explosion validates the model used to describe the propagation of acoustic waves by taking into account expansion, absorption, and non-linear and inhomogeneous effects in the atmosphere and ionosphere.

  15. Pressure transducer used for measuring close-in shock waves of nuclear explosions in the atmosphere

    International Nuclear Information System (INIS)

    This paper introduces a variable reluctance pressure transducer. It has been successfully used for the measurement of close-in shock waves of nuclear explosions in the atmosphere. This transducer's highest pressure range is 100kg/cm2 and its response rise time for all ranges is lms. It uses a specially made oil-filled pressure which allows the transducer to be able to realize underground installation. In this way, it can endure the intense nuclear radiation of nuclear explosions without losing its fast speed response characteristics. This transducer has undergone a series of environmental tests and dynamic standardizations. Therefore, it was used to measure the complete waveform of shock wave overpressure in areas near the fire ball of nuclear explosions. This paper lists the test data of a group of nuclear explosion tests

  16. Radioactive fallout in France after the second Chinese nuclear explosion: atmospheric transfer processes

    International Nuclear Information System (INIS)

    The products released into the atmosphere by the second Chinese nuclear explosion were detected and measured in France during the months of May, June and July 1965. The main results are presented here and discussed. They are considered in particular in the light of the meteorological conditions as a function of the most recent hypotheses concerning transfer processes. (authors)

  17. Numerical Model for Atmospheric Contaminant Clouds from Nuclear Explosions

    Science.gov (United States)

    Kanarska, Y.

    2007-12-01

    Our numerical approach includes fluid mechanical model which is the combination of a compressible GEODYN code and a Low Mach code (LMC). The first one is an explicit code and it is intended to simulate early stages of nuclear explosions up to 15 s. The second one is an implicit code based on a pressure projection method and it is intended to simulate subsequent cloud rise events up to few hours. We perform series of cloud rise scenarios ranging from idealized bubble rise problem to realistic air bursts. We analyze effects of compressible dynamics and different turbulent parameterizations on the cloud evolution. It is found that in a realistic configuration interaction of a reflected shock wave from the ground with a fireball affects significantly cloud evolution in contrast to idealized bubble rise simulations. We show that by providing initial source from compressible GEODYN code, later times flow evolution can be successfully simulated with fast and efficient LMC code. Finally, we develop formalism for tracer particles and their fallout and present some preliminary results. This work was performed in part under the auspices of the U.S. Department of Energy by University of California, Lawrence Livermore National Laboratory under Contract W-7405-Eng-48.

  18. Hot Explosions in the Cool Atmosphere of the Sun

    CERN Document Server

    Peter, H; Curdt, W; Schmit, D; Innes, D; De Pontieu, B; Lemen, J; Title, A; Boerner, P; Hurlburt, N; Tarbell, T D; Wuelser, J P; Martínez-Sykora, J; Kleint, L; Golub, L; McKillop, S; Reeves, K K; Saar, S; Testa, P; Kankelborg, C; Jaeggli, S; Carlsson, M; Hansteen, V

    2014-01-01

    The solar atmosphere was traditionally represented with a simple one-dimensional model. Over the past few decades, this paradigm shifted for the chromosphere and corona that constitute the outer atmosphere, which is now considered a dynamic structured envelope. Recent observations by IRIS (Interface Region Imaging Spectrograph) reveal that it is difficult to determine what is up and down even in the cool 6000-K photosphere just above the solar surface: this region hosts pockets of hot plasma transiently heated to almost 100,000 K. The energy to heat and accelerate the plasma requires a considerable fraction of the energy from flares, the largest solar disruptions. These IRIS observations not only confirm that the photosphere is more complex than conventionally thought, but also provide insight into the energy conversion in the process of magnetic reconnection.

  19. Atmosphere issues in detection of explosives and organic residues

    Science.gov (United States)

    Brown, C. G.; Baudelet, M.; Bridge, C.; Fisher, M. K.; Sigman, M.; Dagdigian, P. J.; Richardson, M.

    2009-05-01

    This study makes a comparison of LIBS emission from molecular species in plasmas produced from organic residues on a non-metallic substrate by both a 5 ns Nd:YAG laser (1064 nm) and a 40 fs Ti:Sapphire laser (800 nm) in air and argon atmospheres. The organic samples analyzed had varying amounts of carbon, nitrogen, hydrogen, and oxygen in their molecular structure. The characterization was based on the atomic carbon, hydrogen, nitrogen, and oxygen lines as well as the diatomic species CN (B2Σ+ - X2Σ+) and the C2 (d3Πg - a3Πu). Principal Component Analysis (PCA) was used to identify similarities of the organic analyte via the emission spectra. The corresponding Receiver Operating Characteristics (ROC) curves show the limitations of the PCA model for the nanosecond regime in air.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-10-01

    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.

  1. Consideration of impact of atmospheric intrusion in subsurface sampling for investigation of suspected underground nuclear explosions

    International Nuclear Information System (INIS)

    Radioactive noble gases radioxenon and radioargon constitute the primary smoking gun of an underground nuclear explosion. The aim of subsurface sampling of soil gas as part of an on-site inspection (OSI) is to search for evidence of a suspected underground nuclear event. It has been hypothesized that atmospheric gas can disturb soil gas concentrations and therefore potentially add to problems in civilian source discrimination verifying treaty compliance under the comprehensive nuclear-test ban treaty. This work describes a study of intrusion of atmospheric air into the subsurface and its potential impact on an OSI using results of simulations from the underground transport of environmental xenon (UTEX) model. (author)

  2. Explosion of comet Shoemaker-Levy 9 on entry into the Jovian atmosphere

    Science.gov (United States)

    Mac Low, Mordecai-Mark; Zahnle, Kevin

    1994-01-01

    We use the astrophysical hydrocode ZEUS to compute high-resolution models of the disruption and deceleration of cometary fragments striking Jupiter. We find that simple analytic and semianalytic models work well for kilometer-size impactors. We show that previous numerical models that placed the explosion much deeper in the atmosphere failed to fully resolve important gasdynamical instabilities. These instabilities tear the comet apart, greatly increase its effective cross section, and bring it to an abrupt halt. A 1 km diameter fragment loses over 90% of its kinetic energy within a single scale height at an atmospheric pressure of order 10 bars. For all practical purposes, it explodes.

  3. Atmospheric pressure chemical ionization of explosives using alternating current corona discharge ion source.

    Science.gov (United States)

    Usmanov, D T; Chen, L C; Yu, Z; Yamabe, S; Sakaki, S; Hiraoka, K

    2015-04-01

    The high-sensitive detection of explosives is of great importance for social security and safety. In this work, the ion source for atmospheric pressure chemical ionization/mass spectrometry using alternating current corona discharge was newly designed for the analysis of explosives. An electromolded fine capillary with 115 µm inner diameter and 12 mm long was used for the inlet of the mass spectrometer. The flow rate of air through this capillary was 41 ml/min. Stable corona discharge could be maintained with the position of the discharge needle tip as close as 1 mm to the inlet capillary without causing the arc discharge. Explosives dissolved in 0.5 µl methanol were injected to the ion source. The limits of detection for five explosives with 50 pg or lower were achieved. In the ion/molecule reactions of trinitrotoluene (TNT), the discharge products of NOx (-) (x = 2,3), O3 and HNO3 originating from plasma-excited air were suggested to contribute to the formation of [TNT - H](-) (m/z 226), [TNT - NO](-) (m/z 197) and [TNT - NO + HNO3 ](-) (m/z 260), respectively. Formation processes of these ions were traced by density functional theory calculations. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26149109

  4. 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.

    1996-02-01

    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.

  5. 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)

    2010-05-01

    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.

  6. ASPECTS REGARDING THE DESIGN AND PERFORMANCE OF FLAMEPROOF ELECTRIC MOTORS SUPPLIED VIA STATIC FREQUENCY CONVERTERS FOR EXPLOSIVE ATMOSPHERES

    Directory of Open Access Journals (Sweden)

    Mihai MAGYARI

    2012-05-01

    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

  7. Acoustic energy transfer to the upper atmosphere from surface chemical and underground nuclear explosions

    Czech Academy of Sciences Publication Activity Database

    Drobzheva, Yana Viktorovna; Krasnov, Valerij Michailovič

    2006-01-01

    Roč. 68, 3-5 (2006), s. 578-585. ISSN 1364-6826 R&D Projects: GA ČR GA205/04/2110 Institutional research plan: CEZ:AV0Z30420517 Keywords : Acoustic wave * Energy * Atmosphere * Ionosphere Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.448, year: 2006

  8. Summary of Calculation Method for Evaluating Atmospheric Explosion Parameter Using Infrasound%次声波估算大气层核爆参数的计算方法综述

    Institute of Scientific and Technical Information of China (English)

    刘伟; 程先友; 郑毅

    2012-01-01

    On the basis of introducing the methods of calculating the distance between atmospheric explosion shooting point and infrasound station, the paper summarizes the analysis results of domestic and international atmospheric explosion infrasonic data, and gives several methods for evaluating atmospheric explosion yield using infrasonic signals.%在介绍大气层核爆炸爆点距次声探测站点之间距离的计算方法基础上,总结国内外的历次核爆次声监测数据分析结果,给出了几种求解大气层核爆当量的经验计算方程式,并进行了分析比较.

  9. Primary explosives

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-06-01

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

  10. Emission of toxic explosive and fire hazardous gases in coal piles stored under atmospheric conditions. Part I

    International Nuclear Information System (INIS)

    Bituminous coal stockpiles stored in open air undergo weathering processes due to low temperature oxidation (40-100 degree C) resulting in quality deterioration. The process is accompanied by emission of hazardous explosive gases such as molecular hydrogen and low molecular weight organic gases. The article describes the process of low temperature oxidation of coal and goes on to report on simulation experiments carried out to assess the oxidation resistance of various coals stored in Israel, performed in small glass batch reactors and on the monitoring of temperatures and gas evolved in large coal piles stored in open air (performed using a portable unit which can penetrate up to 7 meters inside a coal pile). Molecular hydrogen emissions were found in small concentrations, in all types of coal studied. The amount of hydrogen formed in the batch reactors is linearly dependent on the amount of oxygen consumed in the coal oxidation process and also on the temperature. It was only slightly dependent on the coal mass and independent of particle size. Previous published work has only mentioned hydrogen emission at higher temperatures (240 degree C)

  11. Explosive laser

    Science.gov (United States)

    Robinson, C.P.; Jensen, R.J.; Davis, W.C.; Sullivan, J.A.

    1975-09-01

    This patent relates to a laser system wherein reaction products from the detonation of a condensed explosive expand to form a gaseous medium with low translational temperature but high vibration population. Thermal pumping of the upper laser level and de-excitation of the lower laser level occur during the expansion, resulting in a population inversion. The expansion may be free or through a nozzle as in a gas-dynamic configuration. In one preferred embodiment, the explosive is such that its reaction products are CO$sub 2$ and other species that are beneficial or at least benign to CO$sub 2$ lasing. (auth)

  12. Explosive laser

    International Nuclear Information System (INIS)

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

  13. Explosive complexes

    Science.gov (United States)

    Huynh, My Hang V.

    2009-09-22

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

  14. Explosive Joining

    Science.gov (United States)

    1989-01-01

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

  15. Explosive simulants for testing explosive detection systems

    Science.gov (United States)

    Kury, John W.; Anderson, Brian L.

    1999-09-28

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

  16. Leidenfrost explosions

    CERN Document Server

    Moreau, F; Dorbolo, S

    2012-01-01

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

  17. Chaotic Explosions

    CERN Document Server

    Altmann, Eduardo G; Tél, Tamás

    2015-01-01

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

  18. Explosive evaporation in solar flares

    Science.gov (United States)

    Fisher, George H.

    1987-01-01

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

  19. Extrusion cast explosive

    Science.gov (United States)

    Scribner, Kenneth J.

    1985-01-01

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

  20. Seismometric detection of underground nuclear explosions

    International Nuclear Information System (INIS)

    Processes which take place instantaneously after the detonation of the underground nuclear device are explained. Methods to discriminate between nuclear explosions and earthquakes by studying the P-waves and S-waves are described. Empirical relationships have been developed between the magnitude and yield of the explosions. The effect of tectonic strain release on seismic discrimination is mentioned. Propagation of shock waves in atmospheric explosions in compared with the propagation of waves in underground explosions. It is pointed out that underground nuclear explosions are very helpful in the studies on the structure of the interior of the earth to build up velocity models for earthquakes and also to predict earthquakes in some regions. (A.K.)

  1. Radionuclides in an arctic terrestrial ecosystem affected by atmospheric release from the Kraton-3 accidental underground nuclear explosion. 2001-2002

    International Nuclear Information System (INIS)

    Current distributions of artificial radionuclides (ARN) were studied in the main compartments of a larch-tree forest lethally affected by a radioactive release from the Kraton-3 peaceful underground nuclear explosion (65.9 deg N, 112.3 deg E; Yakutia, Russia; 1978). Samples of soil, fungi, lichens, mosses, grasses, shrubs and trees were obtained at points belonging to four zones categorised by the severity of the ecosystem damage. Sampling was supplemented by dose rate measurements in air and mapping. The area of forest characterised by 100% lethality to adult larches (Larix gmelinii) and with partial, visually-detectable damage of other more radio-resistance species (e.g. lichens, mosses) covers a territory of approximately 1.2 km2. Elevated levels of long-lived ARN were found at all sampling sites. Maximum registered levels of the ground contamination with radionuclides of Cs, Sr and Pu were three orders of magnitude higher than those expected from global fallout. The ratios of 137Cs to some other significant radionuclides in the ground contamination were as follows [mean (range)]: 90Sr - 0.57(0.02-0.93); 239,240Pu 44(25-72); 60Co 470(220-760). Twenty-three years after a discrete contamination event, 90-95% of the total deposited radiocesium and plutonium has still remained in the lichen-moss on-ground cover and in the top 5 cm organic soil layer. At the same time, vertical and horizontal migrations of 90Sr in soil were more pronounced. Strong surface contamination with 137Cs, 90Sr and plutonium was detected at the twigs and bark of the dead larches. The young larches that grew at the contaminated area following the initial destruction of the forest demonstrated a substantial ability to accumulate 137Cs, 90Sr and plutonium via roots, while the bushes selectively accumulated mainly radiostrontium. In contrast, some fungi concentrated mostly radiocesium. The levels of gamma dose rate in air and the environmental contamination with 137Cs were found to correspond

  2. Understanding vented gas explosions

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

  3. 寒武纪早期大气-海洋氧含量与生命大爆发%Atmosphere-Ocean Oxygen Levels and Biotic Explosion in the Early Cambrian

    Institute of Scientific and Technical Information of China (English)

    李超; 金承胜

    2015-01-01

    寒武纪早期(541~510,Ma)地球环境与这一时期生命大爆发之间的关系一直是地球生物学研究的热点问题之一。本文系统总结了目前寒武纪早期大气-海洋氧含量与这一时期生命辐射之间关系的3种假说:大气-海洋的氧含量增加导致了寒武纪生命大爆发;寒武纪生命大爆发导致了大气-海洋氧化以及二者之间没有因果关系。3种假说均有相应的支持证据,但也存在与寒武纪早期海洋化学记录、与现代海洋观察不符和上述假说均未考虑寒武纪早期生命演化所展示的时空差异性等问题。在上述3种假说的基础之上,本文通过对寒武纪构造活动、陆源输入、海洋化学和生命演化等最新资料的综合讨论和分析表明:寒武纪早期地球环境与生命辐射之间很可能是相互作用与协同演化关系,而非简单的单向关系。%The relationship between the Earth environment and the biotic explosion in early Cambrian (ca.541 -5 10,Ma) is one top geobiological issue.Here,we systematically summarized three major hypotheses for the relationship between the atmosphere-ocean oxygen level and the biotic evolution in early Cambrian,including that (1)increasing oxygenation of at-mosphere and ocean caused the Cambrian explosion,(2)the emergence and evolution of lives resulted in oxygenation of atmosphere and ocean,(3)the atmosphere-ocean oxygen level and the evolution of lives are not interrelated.Although each hypothesis is supported by specific evidences,these hypotheses show significantly inconsistent with partial ocean chemistry records in early Cambrian and investigations of lives in modern ocean analogues.In addition,the spatiotemporal heterogeneity of early Cambrian life evolution is not considered in these hypotheses.By synthesizing these major hypotheses with available data on Cambrian tectonic activities,terrestrial fluxes,ocean chemistry and life evolution patterns,we dis

  4. Burst conditions of explosive volcanic eruptions recorded on microbarographs

    Science.gov (United States)

    Morrissey, M.M.; Chouet, B.A.

    1997-01-01

    Explosive volcanic eruptions generate pressure disturbances in the atmosphere that propagate away either as acoustic or as shock waves, depending on the explosivity of the eruption. Both types of waves are recorded on microbarographs as 1- to 0.1-hertz N-shaped signals followed by a longer period coda. These waveforms can be used to estimate burst pressures end gas concentrations in explosive volcanic eruptions and provide estimates of eruption magnitudes.

  5. Ionospheric disturbances produced by powerful explosives

    Science.gov (United States)

    Nagorskii, P. M.; Tarashchuk, Yu. E.

    1992-09-01

    Results of a study of wave-like ionospheric disturbances initiated by powerful explosives are presented and analyzed. Three types of wave processes with differing physical natures which propagate in the upper atmosphere and ionosphere to distances of thousands of kilometers are distinguished. The effect of shock-acoustic waves on indirect short wave radio propagation is considered.

  6. Ionospheric disturbances produced by powerful explosives

    International Nuclear Information System (INIS)

    Results of a study of wave-like ionospheric disturbances initiated by powerful explosives are presented and analyzed. Three types of wave processes with differing physical natures which propagate in the upper atmosphere and ionosphere to distances of thousands of kilometers are distinguished. The effect of shock-acoustic waves on indirect short wave radio propagation is considered

  7. Explosives tester with heater

    Science.gov (United States)

    Del Eckels, Joel; Nunes, Peter J.; Simpson, Randall L.; Whipple, Richard E.; Carter, J. Chance; Reynolds, John G.

    2010-08-10

    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.

  8. Dynamics of explosive instability

    International Nuclear Information System (INIS)

    It was shown that in general case explosive instability dynamics should be described as four wave interaction. The main difference from three wave interaction is that this dynamics may not contain explosive instability. Besides it may by irregular. If the characteristics of one of the wave is closed to one of the interacting wave and they are connected linearly then explosive instability may be suppressed.

  9. Intermittent Explosive Disorder

    OpenAIRE

    Lut Tamam; Meliha Zengin Eroglu; Ozlem Paltaci

    2011-01-01

    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. Etio...

  10. Underground Nuclear Explosions and Release of Radioactive Noble Gases

    Science.gov (United States)

    Dubasov, Yuri V.

    2010-05-01

    Over a period in 1961-1990 496 underground nuclear tests and explosions of different purpose and in different rocks were conducted in the Soviet Union at Semipalatinsk and anovaya Zemlya Test Sites. A total of 340 underground nuclear tests were conducted at the Semipalatinsk Test Site. One hundred seventy-nine explosions (52.6%) among them were classified as these of complete containment, 145 explosions (42.6%) as explosions with weak release of radioactive noble gases (RNG), 12 explosions (3.5%) as explosions with nonstandard radiation situation, and four excavation explosions with ground ejection (1.1%). Thirty-nine nuclear tests had been conducted at the Novaya Zemlya Test Site; six of them - in shafts. In 14 tests (36%) there were no RNG release. Twenty-three tests have been accompanied by RNG release into the atmosphere without sedimental contamination. Nonstandard radiation situation occurred in two tests. In incomplete containment explosions both early-time RNG release (up to ~1 h) and late-time release from 1 to 28 h after the explosion were observed. Sometimes gas release took place for several days, and it occurred either through tunnel portal or epicentral zone, depending on atmospheric air temperature.

  11. Explosive Technology Group

    Data.gov (United States)

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

  12. Explosive pulsed power

    CERN Document Server

    Altgilbers, Larry L; Freeman, Bruce L

    2010-01-01

    Explosive pulsed power generators are devices that either convert the chemical energy stored in explosives into electrical energy or use the shock waves generated by explosives to release energy stored in ferroelectric and ferromagnetic materials. The objective of this book is to acquaint the reader with the principles of operation of explosive generators and to provide details on how to design, build, and test three types of generators: flux compression, ferroelectric, and ferromagnetic generators, which are the most developed and the most near term for practical applications. Containing a co

  13. Explosion and detonation characteristics of dimethyl ether.

    Science.gov (United States)

    Mogi, Toshio; Horiguchi, Sadashige

    2009-05-15

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

  14. The radiation effects of nuclear weapons explosions

    International Nuclear Information System (INIS)

    The energy resulting from nuclear weapons explosions consists of thermal energy (heat radiation), shock waves, initial radiation (nuclear ray flash, gamma and neutron flash), and nuclear radiation of the fission products (fallout). The contribution of the different energy components depends on the energy amounts produced by fission or fusion reactions (A-weapon, H-weapon), on the components used for conversion to helium-4 (deuterium, tritium, lithium), the weapon design (radiation absorption and induced activity in auxiliaries), and on the type of employment (atmospheric, ground, or underground explosion). The damaging effects vary accordingly, consisting of thermal damage, blast effects, and radiation injuries. The effects are explained and compared. (orig.)

  15. Steam explosion studies review

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Moon Kyu; Kim, Hee Dong

    1999-03-01

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

  16. Explosions and static electricity

    DEFF Research Database (Denmark)

    Jonassen, Niels M

    1995-01-01

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

  17. Steam explosion studies review

    International Nuclear Information System (INIS)

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

  18. Waveform inversion of acoustic waves for explosion yield estimation

    Science.gov (United States)

    Kim, K.; Rodgers, A.

    2016-07-01

    We present a new waveform inversion technique to estimate the energy of near-surface explosions using atmospheric acoustic waves. Conventional methods often employ air blast models based on a homogeneous atmosphere, where the acoustic wave propagation effects (e.g., refraction and diffraction) are not taken into account, and therefore, their accuracy decreases with increasing source-receiver distance. In this study, three-dimensional acoustic simulations are performed with a finite difference method in realistic atmospheres and topography, and the modeled acoustic Green's functions are incorporated into the waveform inversion for the acoustic source time functions. The strength of the acoustic source is related to explosion yield based on a standard air blast model. The technique was applied to local explosions (structure. The presented method can be extended to explosions recorded at far distance provided proper meteorological specifications.

  19. Double pulse laser-induced breakdown spectroscopy of explosives: Initial study towards improved discrimination

    Science.gov (United States)

    De Lucia, Frank C.; Gottfried, Jennifer L.; Munson, Chase A.; Miziolek, Andrzej W.

    2007-12-01

    Detecting trace explosive residues at standoff distances in real-time is a difficult problem. One method ideally suited for real-time standoff detection is laser-induced breakdown spectroscopy (LIBS). However, atmospheric oxygen and nitrogen contributes to the LIBS signal from the oxygen- and nitrogen-containing explosive compounds, complicating the discrimination of explosives from other organic materials. While bathing the sample in an inert gas will remove atmospheric oxygen and nitrogen interference, it cannot practically be applied for standoff LIBS. Alternatively, we have investigated the potential of double pulse LIBS to improve the discrimination of explosives by diminishing the contribution of atmospheric oxygen and nitrogen to the LIBS signal. These initial studies compare the close-contact (LIBS spectra of explosives using single pulse LIBS in argon with double pulse LIBS in atmosphere. We have demonstrated improved discrimination of an explosive and an organic interferent using double pulse LIBS to reduce the air entrained in the analytical plasma.

  20. Double pulse laser-induced breakdown spectroscopy of explosives: Initial study towards improved discrimination

    International Nuclear Information System (INIS)

    Detecting trace explosive residues at standoff distances in real-time is a difficult problem. One method ideally suited for real-time standoff detection is laser-induced breakdown spectroscopy (LIBS). However, atmospheric oxygen and nitrogen contributes to the LIBS signal from the oxygen- and nitrogen-containing explosive compounds, complicating the discrimination of explosives from other organic materials. While bathing the sample in an inert gas will remove atmospheric oxygen and nitrogen interference, it cannot practically be applied for standoff LIBS. Alternatively, we have investigated the potential of double pulse LIBS to improve the discrimination of explosives by diminishing the contribution of atmospheric oxygen and nitrogen to the LIBS signal. These initial studies compare the close-contact (< 1 m) LIBS spectra of explosives using single pulse LIBS in argon with double pulse LIBS in atmosphere. We have demonstrated improved discrimination of an explosive and an organic interferent using double pulse LIBS to reduce the air entrained in the analytical plasma

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

    International Nuclear Information System (INIS)

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

  2. Optically measured explosive impulse

    Science.gov (United States)

    Biss, Matthew M.; McNesby, Kevin L.

    2014-06-01

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

  3. Research on honeycomb structure explosives and double sided explosive cladding

    International Nuclear Information System (INIS)

    Highlights: • Honeycomb structure explosives are used to ensure the quality of charge. • Double sided explosive cladding can clad two composite plates simultaneously. • The critical thickness of explosives decreased significantly. • The energy efficiency of explosives has been significantly improved. • Experiment results can be better predicted by calculation. - Abstract: In order to resolve the current issues about the backward method of charge and low energy efficiency of explosives, honeycomb structure explosives and double sided explosive cladding were used in the present study. Honeycomb structure explosives are used to ensure the quality of charge. Double sided explosive cladding can clad two composite plates simultaneously. Honeycomb structure explosives and double sided explosive cladding, which significantly reduce the critical thickness of stable detonation of explosives, are used to increase the energy efficiency of explosives and save the amount of explosives. Emulsion explosives with the thickness of 5 mm can be stable detonation. In this paper, the experiment of double sided explosive cladding for two groups of steel of No. 45 with the thickness of 2 mm to steel of Q235 with the thickness of 16 mm and two groups of stainless steel with the thickness of 3 mm to steel of Q235 with the thickness of 16 mm were successfully investigated. Without constraints, the critical diameter of emulsion explosives is 14–16 mm. Compared to the existing explosive cladding method, the consumption of explosives for steel of No. 45 to steel of Q235 and stainless steel to steel of Q235 are reduced by 83% and 77% in the case of cladding the same number of composite plates. The explosive cladding windows and collision velocity of flyer plate were calculated before experiment. It shows that the calculation prefigures exactly the explosive cladding for steel of No. 45 to steel of Q235 and stainless steel to steel of Q235

  4. Liquid explosives detection

    Science.gov (United States)

    Burnett, Lowell J.

    1994-03-01

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

  5. Explosive Components Facility

    Data.gov (United States)

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

  6. Parametric Explosion Spectral Model

    Energy Technology Data Exchange (ETDEWEB)

    Ford, S R; Walter, W R

    2012-01-19

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

  7. Intermittent Explosive Disorder

    Directory of Open Access Journals (Sweden)

    Lut Tamam

    2011-09-01

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

  8. Modeling nuclear explosion

    Science.gov (United States)

    Redd, Jeremy; Panin, Alexander

    2012-10-01

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

  9. Shock waves & explosions

    CERN Document Server

    Sachdev, PL

    2004-01-01

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

  10. Chemical Explosion Database

    Science.gov (United States)

    Johansson, Peder; Brachet, Nicolas

    2010-05-01

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

  11. Modelling of gas explosions

    OpenAIRE

    Vågsæther, Knut

    2010-01-01

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

  12. Mass extinctions and supernova explosions

    CERN Document Server

    Korschinek, Gunther

    2016-01-01

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

  13. 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)

    1995-06-01

    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.

  14. Calculation of ionospheric effects due to acoustic radiation from an underground nuclear explosion

    Science.gov (United States)

    Rudenko, G. V.; Uralov, A. M.

    1995-03-01

    Within the framework of the ionospheric detection of underground nuclear tests, we have developed analytic computing technique for the acoustic effect of a confined nuclear explosion on upper layers of the Earth's atmosphere. The relationship is obtained, which relates the nuclear test parameters (depth, explosion yield, and mechanical properties of the rock) to the vertical displacement of the ionosphere produced by the shock wave over the explosion's epicenter. It is also shown that most of the acoustic energy produced by a confined underground nuclear explosion escapes upward, with only a small fraction being captured by the atmospheric waveguide.

  15. Peaceful nuclear explosions

    International Nuclear Information System (INIS)

    This paper reports on studies of the results of U.S. programs for the application of peaceful nuclear explosions which make it clear that they are not particularly attractive to the United States at this time, and that there is no significant indication that they will have commercial utilization by 1990. Although one must make allowances for different situations in other countries, there do not appear to be any obvious technical or economic reasons why this somewhat negative conclusion should not apply to virtually all other nations as well. This does not constitute an argument against R and D on possible peaceful uses, given the many technical unknowns and economic uncertainties. It does, however, strongly suggest that if continued testing of peaceful nuclear explosions represents a substantial interference to desirable arms control or disarmament objectives, the potential benefits from peaceful nuclear explosions would not appear to be sufficient to permit their testing to stand in the way. Specifically, it is hard to see why concern about peaceful nuclear explosions should interfere with negotiations toward a comprehensive test ban treaty. At the very minimum, a 10-year world moratorium on testing or use of peaceful nuclear explosions would seem to be a modest price to pay for the significant progress toward arms control and detente which a comprehensive test ban treaty could represent

  16. R-22 vapor explosions

    International Nuclear Information System (INIS)

    Previous experimental and theoretical studies of R-22 vapor explosions are reviewed. Results from two experimental investigations of vapor explosions in a medium scale R-22/water system are reported. Measurements following the drop of an unrestrained mass of R-22 into a water tank demonstrated the existence of two types of interaction behavior. Release of a constrained mass of R-22 beneath the surface of a water tank improved the visual resolution of the system thus allowing identification of two interaction mechansims: at low water temperatures, R-22/water contact would produce immediate violent boiling; at high water temperatures a vapor film formed around its R-22 as it was released, explosions were generated by a surface wave which initiated at a single location and propagated along the vapor film as a shock wave. A new vapor explosion model is proposed, it suggests explosions are the result of a sequence of three independent steps: an initial mixing phase, a trigger and growth phase, and a mature phase where a propagating shock wave accelerates the two liquids into a collapsing vapor layer causing a high velocity impact which finely fragments and intermixes the two liquids

  17. Multidimensional detection of explosives and explosive signatures via laser electrospray mass spectrometry

    Science.gov (United States)

    Brady, John J.; Flanigan, Paul M., IV; Perez, Johnny J.; Judge, Elizabeth J.; Levis, Robert J.

    2012-06-01

    Nitro- and inorganic-based energetic material is vaporized at atmospheric pressure using nonresonant, 70 femtosecond laser pulses prior to electrospray post-ionization and transfer into a time-of-flight mass spectrometer for mass analysis. Measurements of a nitro-based energetic molecule, cyclotrimethylenetrinitramine (RDX), adsorbed on metal and dielectric surfaces indicate nonresonant vaporization of intact molecules, demonstrating the universality of laser electrospray mass spectrometry (LEMS) technique for explosives. In addition, RDX is analyzed at a distance of 2 meters to demonstrate the remote detection capability of LEMS. Finally, the analysis and multivariate statistical classification of inorganic-based explosives containing ammonium nitrate, chlorate, perchlorate, black powder, and an organic-based explosive is presented, further expanding the capabilities of the LEMS technique for detection of energetic materials.

  18. 78 FR 64246 - Commerce in Explosives; List of Explosives Materials

    Science.gov (United States)

    2013-10-28

    ... supersedes the List of Explosives Materials dated September 20, 2012 (Docket No. ATF 47N, 77 FR 58410.... Tetrazene [tetracene, tetrazine, 1(5-tetrazolyl)-4-guanyl tetrazene hydrate]. Tetrazole explosives....

  19. Portable raman explosives detection

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-01-01

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

  20. Propagation in thermal explosions

    International Nuclear Information System (INIS)

    In a number a small scale experiments the propagation phenomena in thermal explosions caused by contact of a molten metal with water were studied. To investigate the rapid vapor-blanket collapse a small amount of molten tin (800 deg C) was poured on to a crucible under water at decreased pressure. After pressurization to 1 bar the pressure rise in the vessel was measured and the occurring events were observed by cinephotography (8000ps-1). The experiment showed that explosion propagation by blanket collapse is energetically possible. Similar experiments were performed with a larger interacting surface in a through shaped and in a think tank shaped arrangement, which demonstrated that propagation actually occured; the propagation velocity could be estimated to about 5-103cm s-1. The findings favour the interpretation that the explosion is driven by fragmentation rather than by super heat. Fragmentation or mixing can occur through self-driven collapse and possibly by penetration of coolant jets formed by the collapse in the blanket. In a continuously propagation explosion, Taylor and Kelvin-Helmholtz instabilities may take part in the mixing process

  1. NUMERICAL MODEL FOR THE KRAKATOA HYDROVOLCANIC EXPLOSION AND TSUNAMI

    Directory of Open Access Journals (Sweden)

    Charles L. Mader

    2006-01-01

    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.

  2. Explosive cyclones in CMIP5 climate models

    Science.gov (United States)

    Seiler, C.; Zwiers, F. W.

    2014-12-01

    Explosive cyclones are rapidly intensifying low pressure systems with severe wind speeds and precipitation, affecting livelihoods and infrastructure primarily in coastal and marine environments. A better understanding of the potential impacts of climate change on these so called meteorological bombs is therefore of great societal relevance. This study evaluates how well CMIP5 climate models reproduce explosive cyclones in the extratropics of the northern hemisphere, and how these bombs respond to global warming. For this purpose an objective-feature tracking algorithm was used to identify and track extratropical cyclones from 25 CMIP5 models and 3 reanalysis products for the periods 1980 to 2005 and 2070 to 2099. Cyclones were identified as the maxima of T42 vorticity of 6h wind speed at 850 hPa. Explosive and non-explosive cyclones were separated based on the corresponding deepening rates of mean sea level pressure. Most models accurately reproduced the spatial distribution of bombs when compared to results from reanalysis data (R2 = 0.84, p-value = 0.00), with high frequencies along the Kuroshio Current and the Gulf Stream, as well as the exit regions of the polar jet streaks. Most models however significantly underestimated bomb frequencies by a third on average, and by 74% in the most extreme case. This negative frequency bias coincided with significant underestimations of either meridional sea surface temperature (SST) gradients, or wind speeds of the polar jet streaks. Bomb frequency biases were significantly correlated with the number vertical model levels (R2= 0.36, p-value = 0.001), suggesting that the vertical atmospheric model resolution is crucial for simulating bomb frequencies accurately. The impacts of climate change on the location, frequency, and intensity of explosive cyclones were then explored for the Representative Concentration Pathway 8.5. Projections were related to model bias, resolution, projected changes of SST gradients, and wind speeds

  3. Gas cloud explosions and resulting blast effects

    International Nuclear Information System (INIS)

    The design of nuclear power plant structures to resist blast effects due to chemical explosions requires the determination of load-time functions of possible blast waves. Whether the explosion of a hydrocarbon gas in the atmosphere will occur in the form of a deflagration or a detonation is largely depending on the type of the flame acceleration process which is closely related to the rate of energy release. Flame propagations at normal flame velocities in a free explosible gas cloud will certainly not lead to a detonation. With sufficiently large clouds, however, the flame acceleration could become so high that an initial deflagration changes into a detonative process. Results of recent investigations, which will be discussed in detail, show that in a free cloud with deflagrative ignition (flame, heated wire, sparks) the occurrence of a gas detonation can practically be excluded. Apparently, free gas clouds can only be induced to detonate by a sufficiently strong detonative initiation. Independently from the initiating event (deflagration, detonation) in the practice of damage analysis it has become customary to describe the consequences of an explosion event by means of the so-called TNT-equivalent. Therefore, it is attempted to specify this equivalent for hydrocarbons by means of energetic considerations including the propagation functions for the case of spherically symmetric detonations. In correspondence with U.S. recommendations it follows that with regard to the effects, 1 kg of hydrocarbon could be equated to about 1 kg TNT. In analogous manner to the safety distances required in the handling and storage of high-explosives a mass-distance relation of the form R = k x Lsup(1/3) could be considered, where L is the mass of spontaneously released hydrocarbon and k varies only with the structural shape of the blast loaded buildings. (orig./HP)

  4. Direct real-time detection of vapors from explosive compounds.

    Science.gov (United States)

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

    2013-11-19

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

  5. Electromagnetic pulse from nuclear explosions

    International Nuclear Information System (INIS)

    The effect of the electromagnetic pulse (EMP) accompanying a nuclear explosion on electronic equipment is presented largely in the form of examples of damage to equipment during nuclear test explosions. The range of such effects is related to the height above the ground at which the explosion takes place. Electric fields and currents generated by EMP in a number of tests, as measured or estimated at various distances are cited. Underground explosions only give EMP over short distances, less than 30 km, while the EMP from conventional explosions is weak and has no significance for electronic equipment. (JIW)

  6. Development of explosive plugging for steam generator tubes

    International Nuclear Information System (INIS)

    This paper reports the development of explosive plugging techniques as a repair method for leaking steam generator tubes. The study has been in progress since 1977 and results confirm that the explosive plugging method is applicable to the steam generator. The following developmental tests were performed. 1. Preliminary test - Kind and amount of explosive, shape of plug, stand-off, initiation method, etc. 2. Evaluation test - Shearing test, measurement of bonded zone (U.T. and microscopic observation), He-leakage test, water pressure test, hardness of plug and tube after plugging, P.T. for plugged tube plate surface, etc. 3. Re-plugging after failed plugging 4. Demonstration plugging of a 50 MW steam generator 5. Thermal shock test 6. Sodium vapour atmosphere test The results of these tests indicate that the explosive plugging method is effective for the repair of leaking tubes in steam generators. (author)

  7. Explosive bulk charge

    Science.gov (United States)

    Miller, Jacob Lee

    2015-04-21

    An explosive bulk charge, including: a first contact surface configured to be selectively disposed substantially adjacent to a structure or material; a second end surface configured to selectively receive a detonator; and a curvilinear side surface joining the first contact surface and the second end surface. The first contact surface, the second end surface, and the curvilinear side surface form a bi-truncated hemispherical structure. The first contact surface, the second end surface, and the curvilinear side surface are formed from an explosive material. Optionally, the first contact surface and the second end surface each have a substantially circular shape. Optionally, the first contact surface and the second end surface consist of planar structures that are aligned substantially parallel or slightly tilted with respect to one another. The curvilinear side surface has one of a smooth curved geometry, an elliptical geometry, and a parabolic geometry.

  8. Phytoremediation of explosives

    Czech Academy of Sciences Publication Activity Database

    Vaněk, Tomáš; Podlipná, Radka; Hebner, A.; Vavříková, Zuzana; Gerth, A.; Thomas, H.; Smrček, S.

    Krakow : -, 2005, s. 55. [Advanced Research Workshop. Viable methods of soil and water pollution monitoring, protection and remediation: development and use. Krakow (PL), 26.06.2005-01.07.2005] R&D Projects: GA MŠk(CZ) 1P05OC042; GA MŠk(CZ) ME 493 Institutional research plan: CEZ:AV0Z40550506 Keywords : explosives * TNT * phytoremediation Subject RIV: DK - Soil Contamination ; De-contamination incl. Pesticides

  9. High explosive compound

    Science.gov (United States)

    Crawford, Theodore C.

    1976-01-01

    1. A low detonation velocity explosive consisting essentially of a particulate mixture of ortho-boric acid and trinitrotoluene, said mixture containing from about 25 percent to about 65 percent by weight of ortho-boric acid, said ortho-boric acid comprised of from 60 percent to 90 percent of spherical particles having a mean particle size of about 275 microns and 10 percent to 40 percent of spherical particles having a particle size less than about 44 microns.

  10. Explosions in November

    OpenAIRE

    Steinitz, Richard

    2011-01-01

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

  11. Phytoremediation of explosives

    Czech Academy of Sciences Publication Activity Database

    Vaněk, Tomáš; Nepovím, Aleš; Hebner, A.; Soudek, Petr; Gerth, A.; Thomas, H.; Smrček, S.

    Pisa: CNR Research Campus, 2005, s. 137. [Phytotechnologies to promote sustainable land use and improve food safety . Scientific Workshop and Management Committee Meeting /1./. Pisa (IT), 14.06.2005-16.06.2005] R&D Projects: GA MŠk(CZ) 1P05OC042; GA MŠk(CZ) ME 493 Institutional research plan: CEZ:AV0Z40550506 Keywords : phytoremediation * explosives Subject RIV: DK - Soil Contamination ; De-contamination incl. Pesticides

  12. Explosives signatures and analysis

    Science.gov (United States)

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

    2008-04-01

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

  13. Spectral Signatures of Gravitationally Confined Thermonuclear Supernova Explosions

    CERN Document Server

    Kasen, D; Kasen, Daniel; Plewa, Tomasz

    2005-01-01

    We consider some of the spectral and polarimetric signatures of the gravitational confined detonation scenario for Type Ia supernova explosions. In this model, material produced by an off-center deflagration (which itself fails to produce the explosion) forms a metal-rich atmosphere above the white dwarf surface. Using hydrodynamical simulations, we show that this atmosphere is compressed and accelerated during the subsequent interaction with the supernova ejecta. This leads ultimately to the formation of a high-velocity pancake of metal-rich material that is geometrically detached from the bulk of the ejecta. When observed at the epochs near maximum light, this absorbing pancake produces a highly blueshifted and polarized calcium IR triplet absorption feature similar to that observed in several Type~Ia supernovae. We discuss the orientation effects present in our model and contrast them to those expected in other supernova explosion models. We propose that a large sample of spectropolarimetric observations c...

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

    Energy Technology Data Exchange (ETDEWEB)

    Phelan, James M.; Patton, Robert Thomas

    2004-08-01

    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.

  15. Characteristic Research on Evaporated Explosive Film

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

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

  16. Experimental characterization of explosively generated aerosols from radiological material surrogates

    International Nuclear Information System (INIS)

    Full text: Radiological Dispersal Devices (RDDs) are of increasing interest in the media and therefore also with emergency planners and risk assessors. When assessing the potential risks associated with RDDs, a key question is the dispersibility of radioactive material under explosive loads. Canada has a project, funded under the CBRNE Research and Technology Initiative (CRTI), to fill gaps in our knowledge of explosive dispersal of radiological material. This project quantifies both the amount and the physical form of the aerosol generated in such an event and uses these properties to predict the potential biological effects of explosively dispersed radioactive material. Characterization of explosively generated aerosols, using non-radioactive simulant for radiological material is taking place at Defence R and D Canada - Valcartier. DRDC Valcartier has an extensive explosives test range and is capable of performing these experiments in both closed and open environments. Indoor testing began in September 2005, with approximately 25 of these tests performed to date. These indoor tests were used to determine both the amount and the particle size distribution of the explosively generated aerosols. To complement the source term data determined from the indoor tests, a series of outdoor explosive trials began in October 2005. These outdoor tests used benign tracer materials, characterized in indoor explosive testing, to simulate release in real atmospheric conditions. The generated plume was tracked using a LIDAR system and these measurements of the plume evolution were used to develop a short-distance-scale dispersion model using a neural network. Results of the indoor and outdoor explosive tests are presented, along with health physics risk assessments based upon measured parameters and simulations.

  17. Gas explosion characterization, wave propagation

    International Nuclear Information System (INIS)

    A number of experiments have been performed with blast waves arising from the ignition of homogeneous and well defined mixtures of methane, oxygen and nitrogen, contained within spherical balloons with controlled initial dimensions. The maximum flame speed has been of the order of 100 m/s, resulting in positive peak pressures of 50-100x102Pa in 5-10 m distance from the source. The explosion process was found to be reasonable symmetric. The attenuation of the blast wave due to vegetation and the influence of obstacles as banks, walls and houses on the pressure field have been investigated. The presence of the bank and the house was felt in a zone with a length corresponding to a typical dimension of the obstacles, whereas the overall pressure field is shown to be unaffected by the the type of obstacles and vegetation investigated. For the wall and house, reflection factors have been established, and some variation over the surface has been measued. The scatter of the pressure measurements is estimated for stable, neutral and unstable atmospheric conditions, and an attempt to determine the ground reflection factor has been performed. Finally the accelerations of a house exposed to the blast wave have been examined. (author)

  18. Explosion protection of fuel supply systems.; Explosionsschutz im Bereich der Brennstoffversorgung

    Energy Technology Data Exchange (ETDEWEB)

    Hoetger, Jens; Klose, Stephanie [DMT GmbH und Co. KG, Dortmund (Germany). Zentrum fuer Brand- und Explosionsschutz

    2013-10-01

    Due to the flammability of the substances used, the risk of explosions cannot be excluded in the fuel supply system of power plants. In contrast to flammable gases and liquids, solid combustibles are normally handled in the presence of air. The fine portion of these combustibles is able to form explosive atmospheres. The use of imported coals requires reviewing the risk assessment of explosion protection. The use of biomass also requires detailed assessment of explosion risks based on the properties of the substances. (orig.)

  19. Explosive events associated with a surge

    CERN Document Server

    Madjarska, M S; De Pontieu, B

    2009-01-01

    The solar atmosphere contains a wide variety of small-scale transient features. Here, we explore the inter-relation between some of them such as surges, explosive events and blinkers via simultaneous spectral and imaging data taken with the TRACE imager, the SUMER, and CDS spectrometers on board SoHO, and SVST La Palma. The alignment of all data both in time and solar XY shows that SUMER line profiles, which are attributed to explosive events, are due to a surge phenomenon. The surge is triggered, most probably, by one or more Elerman bombs which are best visible in Halpha +-350 A but were also registered by TRACE Fe IX/X 171 A and correspond to a strong radiance increase in the CDS Mg IX 368.07 A line. With the present study we demonstrate that the division of small-scale transient events into a number of different subgroups, for instance explosive events, blinkers, spicules, surges or just brightenings, is ambiguous, implying that the definition of a feature based only on either spectroscopic or imaging cha...

  20. Gas explosions in process pipes

    OpenAIRE

    Kristoffersen, Kjetil

    2004-01-01

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

  1. The thermodynamics of thermal explosions

    International Nuclear Information System (INIS)

    Thermal explosions can occur when a hot liquid mixes with a cooler, volatile liquid. Measured explosion efficiencies do not exceed two or three percent, but simple thermodynamic analysis predicts twenty or thirty percent. The difference is crucial in some nuclear reactor safety problems. The mechanisms thought to operate in thermal explosions are considered, and an alternative thermodynamic approach proposed, which takes account of certain irreversibilities in the process, and predicts much lower efficiencies. (author)

  2. PROBABILISTIC MODELING OF EXPLOSIVE LOADING

    OpenAIRE

    Mkrtychev Oleg Vartanovich; Dorozhinskiy Vladimir Bogdanovich

    2012-01-01

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

  3. Explosive hydrogen burning

    International Nuclear Information System (INIS)

    Although an impressive quantity of work has been devoted to understanding nucleosynthesis during explosive hydrogen burning, much work remain to be done. Reactions which occur in novae, x-ray bursts, and supernovae are discussed. Much attention is given to the reactions of hot CNO cycles and of reactions in the rp-process. The many reactions described in this review are not all of the reactions which may be of interest to nuclear physicists, although the rates of those reactions not discussed are essentially unknown. 123 refs., 9 figs

  4. Wire explosion in water

    Czech Academy of Sciences Publication Activity Database

    Prukner, Václav; Koláček, Karel; Schmidt, Jiří; Frolov, Oleksandr; Štraus, Jaroslav

    Praha, 2007 - (Schmidt, J.; Simek, M.; Pekarek, S.; Prukner, V.). s. 145-145 ISBN 978-80-87026-00-7. [XXVIII International conference on phenomena in ionized gases ICPIG’07/28th./. 15.7.2007-20.7.2007, Prague] R&D Projects: GA ČR GA202/06/1324; GA AV ČR KJB100430702; GA MŠk 1P04LA235 Institutional research plan: CEZ:AV0Z20430508 Keywords : Wire explosion * x-ray * laser * plasma Subject RIV: BL - Plasma and Gas Discharge Physics

  5. Wire explosion in water

    Czech Academy of Sciences Publication Activity Database

    Prukner, Václav; Koláček, Karel; Schmidt, Jiří; Frolov, Oleksandr; Štraus, Jaroslav

    Prague: Institute of Plasma Physics AS CR,v.v.i, 2008 - (Schmidt, J.; Šimek, M.; Pekárek, S.; Prukner, V.), s. 1279-1281. (ICPIG. 28). ISBN 978-80-87026-01-4. [XXVIII International conference on phenomena in ionized gases ICPIG’07. Prague (CZ), 15.07.2007-20.07.2007] R&D Projects: GA ČR GA202/06/1324; GA AV ČR KJB100430702; GA MŠk 1P04LA235 Institutional research plan: CEZ:AV0Z20430508 Keywords : Wire explosion * x-ray * laser * plasma Subject RIV: BL - Plasma and Gas Discharge Physics

  6. Spectral Anlysis on Explosive Percolation

    CERN Document Server

    Chung, Ning Ning; Lai, Choy Heng

    2013-01-01

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

  7. Sensitivity of numerical dispersion modeling to explosive source parameters

    International Nuclear Information System (INIS)

    The calculation of downwind concentrations from non-traditional sources, such as explosions, provides unique challenges to dispersion models. The US Department of Energy has assigned the Atmospheric Release Advisory Capability (ARAC) at the Lawrence Livermore National Laboratory (LLNL) the task of estimating the impact of accidental radiological releases to the atmosphere anywhere in the world. Our experience includes responses to over 25 incidents in the past 16 years, and about 150 exercises a year. Examples of responses to explosive accidents include the 1980 Titan 2 missile fuel explosion near Damascus, Arkansas and the hydrogen gas explosion in the 1986 Chernobyl nuclear power plant accident. Based on judgment and experience, we frequently estimate the source geometry and the amount of toxic material aerosolized as well as its particle size distribution. To expedite our real-time response, we developed some automated algorithms and default assumptions about several potential sources. It is useful to know how well these algorithms perform against real-world measurements and how sensitive our dispersion model is to the potential range of input values. In this paper we present the algorithms we use to simulate explosive events, compare these methods with limited field data measurements, and analyze their sensitivity to input parameters. 14 refs., 7 figs., 2 tabs

  8. Explosion-Induced Implosions of Cylindrical Shell Structures

    Science.gov (United States)

    Ikeda, C. M.; Duncan, J. H.

    2010-11-01

    An experimental study of the explosion-induced implosion of cylindrical shell structures in a high-pressure water environment was performed. The shell structures are filled with air at atmospheric pressure and are placed in a large water-filled pressure vessel. The vessel is then pressurized to various levels P∞=αPc, where Pc is the natural implosion pressure of the model and α is a factor that ranges from 0.1 to 0.9. An explosive is then set off at various standoff distances, d, from the model center line, where d varies from R to 10R and R is the maximum radius of the explosion bubble. High-speed photography (27,000 fps) was used to observe the explosion and resulting shell structure implosion. High-frequency underwater blast sensors recorded dynamic pressure waves at 6 positions. The cylindrical models were made from aluminum (diameter D = 39.1 mm, wall thickness t = 0.89 mm, length L = 240 mm) and brass (D = 16.7 mm, t = 0.36 mm, L=152 mm) tubes. The pressure records are interpreted in light of the high-speed movies. It is found that the implosion is induced by two mechanisms: the shockwave generated by the explosion and the jet formed during the explosion-bubble collapse. Whether an implosion is caused by the shockwave or the jet depends on the maximum bubble diameter and the standoff distance.

  9. Shock Initiated Reactions of Reactive Multiphase Blast Explosives

    Science.gov (United States)

    Wilson, Dennis; Granier, John; Johnson, Richard; Littrell, Donald

    2015-06-01

    This paper describes a new class of reactive multiphase blast explosives (RMBX) and characterization of their blast characteristics. These RMBXs are non-ideal explosive compositions of perfluoropolyether (PFPE), nano aluminum, and a micron-size high-density reactive metal - Tantalum, Zirconium, or Zinc in mass loadings of 66 to 83 percent. Unlike high explosives, these PFPE-metal compositions release energy via a fast self-oxidized combustion wave (rather than a true self-sustaining detonation) that is shock dependent, and can be overdriven to control energy release rate. The term ``reactive multiphase blast'' refers to the post-dispersion blast behavior: multiphase in that there are a gas phase that imparts pressure and a solid (particulate) phase that imparts momentum; and reactive in that the hot metal particles react with atmospheric oxygen and the explosive gas products to give an extended pressure pulse. The RMBX formulations were tested in two spherical core-shell geometries - an RMBX shell exploded by a high explosive core, and an RMBX core imploded by a high explosive shell. The fireball and blast characteristics were compared to a C-4 baseline charge.

  10. Controlled by Distant Explosions

    Science.gov (United States)

    2007-03-01

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

  11. Explosion proof device

    International Nuclear Information System (INIS)

    A chamber for carrying in/out equipments of a nuclear facility building has a shutter capable of stopping at a predetermined position and an air curtain disposed at an opening formed upon stopping of the shutter. An openable/closable partition comprises a glass door as a rupture disk. The shutter is closed as a partition for the first and the second chambers for carrying in/out equipments to divide a radiation area. The shutter is stopped near the upper end of the air curtain by a limit switch, and the air curtain is driven at the opening portion from the lower end of the shutter to the floor of the building. Since operators can freely pass the opening from the lower end of the shutter to the floor of the building, and the opening area is ensured, even if missiles are rushed from the outside breaking through the shutter to ignite loaded burnable materials, acceleration of flames is moderated to prevent explosion. Since the glass door is made of the rupture disk and broken, even if burnable materials loaded on the missiles from the outside are burnt, no explosion is caused. (N.H.)

  12. Tenderizing Meat with Explosives

    Science.gov (United States)

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

    2001-06-01

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

  13. Peaceful nuclear explosions

    International Nuclear Information System (INIS)

    Article V of the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) specifies that the potential benefits of peaceful applications of nuclear explosions be made available to non-nuclear weapon states party to the Treaty 'under appropriate international observation and through appropriate international procedures'. The International Atomic Energy Agency's responsibility and technical competence in this respect have been recognized by its Board of Governors, the Agency's General Conference and the United Nations' General Assembly. Since 1968 when the United Nations Conference of Non-Nuclear Weapon States also recommended that the Agency initiate the necessary studies in the peaceful nuclear explosions (PNE) field, the Agency has taken the following steps: 1. The exchange of scientific and technical information has been facilitated by circulating information on the status of the technology and through the Agency's International Nuclear Information System. A bibliography of PNE-related literature was published in 1970. 2. In 1972, guidelines for 'the international observation of PNE under the provisions of NPT and analogous provisions in other international agreements' were developed and approved by the Board of Governors. These guidelines defined the basic purpose of international observation as being to verify that in the course of conducting a PNE project the intent and letter of Articles I and II of the NPT are not violated. 3. In 1974, an advisory group developed 'Procedures for the Agency to Use in Responding to Requests for PNE-Related Services'. These procedures have also been approved by the Board of Governors. 4. The Agency has convened a series of technical meetings which reviewed the 'state-of-the- art'. These meetings were convened in 1970, 1971, 1972 and in January 1975. The Fourth Technical Committee was held in Vienna from 20-24 January 1975 under the chairmanship of Dr. Allen Wilson of Australia with Experts from: Australia, France, Federal

  14. Kaliski's explosive driven fusion experiments

    International Nuclear Information System (INIS)

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

  15. Lidar Detection of Explosives Traces

    OpenAIRE

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

    2016-01-01

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

  16. Nucleosynthesis in stellar explosions

    Energy Technology Data Exchange (ETDEWEB)

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

    1983-01-01

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

  17. Mixing in explosions

    Energy Technology Data Exchange (ETDEWEB)

    Kuhl, A.L.

    1993-12-01

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

  18. Nucleosynthesis in stellar explosions

    International Nuclear Information System (INIS)

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

  19. Direct imaging of explosives

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2009-05-01

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

  1. Hydrogen/hydrocarbon explosions in the ITER vacuum vessel

    International Nuclear Information System (INIS)

    The consequences of H2/hydrocarbon detonations in the vacuum vessel (torus) of the International Thermonuclear Experimental Reactor (ITER) have been studied. The most likely scenario for such a detonation involves a water leak into the torus and a vent of the torus to atmosphere, permitting the formation of an explosive fuel-air mixture. The generation of fuel gases and possible sources of air or oxygen are reviewed, and the severity and effects of specific fuel-air mixture explosions are evaluated. Detonation or deflagration of an explosive mixture could result in pressures exceeding the maximum allowable torus pressure. Further studies to examine the design details and develop an event-tree study of events following a gas detonation are recommended

  2. Discriminating between explosions and earthquakes

    Science.gov (United States)

    Cho, Kwang-Hyun

    2014-12-01

    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.

  3. Explosive signatures: Pre & post blast

    Science.gov (United States)

    Bernier, Evan Thomas

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

  4. Our Explosive Sun

    Science.gov (United States)

    Brown, D. S.

    2009-01-01

    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…

  5. A method for detecting explosives

    International Nuclear Information System (INIS)

    Bombs concealed in luggage have threatened human life and property throughout the world's traffic. The plastic explosives could not be checked by the X-ray detecting device. A method has been tested in the present work for non-destructive detection of explosives. A neutron generator and relevant apparatus have been used as a tool to find explosives, regardless of the bomb's shape and the packing materials. It seems that this method is a promising one because of the strong transmission ability of both the incident and output specific radiations and low background. (author) 4 figs.; 4 tabs

  6. Noise From Shallow Underwater Explosions

    Science.gov (United States)

    Soloway, Alexander G.

    Naval activities such as ordnance disposal, demolition and requisite training, can involve detonation of small explosive charges in shallow water that have the potential to harm nearby marine life. Measurements of the underwater sound generated by sub-surface explosions were collected as part of a naval training exercise. In this thesis the noise levels from these explosions will be investigated using peak pressure, sound exposure level and energy spectral density. Measurements of very-low frequency Scholte interface waves will also be presented and used to investigate elastic parameters in the sediment.

  7. Detection of explosives with laser-induced breakdown spectroscopy

    Science.gov (United States)

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

    2012-12-01

    Our recent work on the detection of explosives by laser-induced breakdown spectroscopy (LIBS) is reviewed in this paper. We have studied the physical mechanism of laser-induced plasma of an organic explosive, TNT. The LIBS spectra of TNT under single-photon excitation are simulated using MATLAB. The variations of the atomic emission lines intensities of carbon, hydrogen, oxygen, and nitrogen versus the plasma temperature are simulated too. We also investigate the time-resolved LIBS spectra of a common inorganic explosive, black powder, in two kinds of surrounding atmospheres, air and argon, and find that the maximum value of the O atomic emission line SBR of black powder occurs at a gate delay of 596 ns. Another focus of our work is on using chemometic methods such as principle component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) to distinguish the organic explosives from organic materials such as plastics. A PLS-DA model for classification is built. TNT and seven types of plastics are chosen as samples to test the model. The experimental results demonstrate that LIBS coupled with the chemometric techniques has the capacity to discriminate organic explosive from plastics.

  8. Explosive actuated valves

    Science.gov (United States)

    Cobb, Jr., Lawrence L.

    1983-01-01

    1. A device of the character described comprising the combination of a generally tubular housing having an end portion forming a chamber to receive the sensitive portion of an explosive squib, a plunger within said housing having an end portion exposed to said chamber, squib retaining means for engaging said housing and a said squib to releasably maintain the squib in close proximity to said plunger end portion including a retaining ring of fusible material spaced outwardly from and encircling at least part of a said squib and part of its sensitive portion for reception of heat from an external source prior to appreciable reception thereof by the sensitive portion of the squib, an annular compression spring bearing at one end against said housing for urging at least a portion of the squib retaining means and a said squib away from said housing and from said plunger end portion upon subjection of the fusible material to heat sufficient to melt at least a portion thereof, and guide means for said spring to maintain even expansion thereof as a said squib is being urged away from said housing.

  9. Explosive actuated valve

    Science.gov (United States)

    Byrne, Kenneth G.

    1983-01-01

    1. A device of the character described comprising the combination of a housing having an elongate bore and including a shoulder extending inwardly into said bore, a single elongate movable plunger disposed in said bore including an outwardly extending flange adjacent one end thereof overlying said shoulder, normally open conduit means having an inlet and an outlet perpendicularly piercing said housing intermediate said shoulder and said flange and including an intermediate portion intersecting and normally openly communicating with said bore at said shoulder, normally closed conduit means piercing said housing and intersecting said bore at a location spaced from said normally open conduit means, said elongate plunger including a shearing edge adjacent the other end thereof normally disposed intermediate both of said conduit means and overlying a portion of said normally closed conduit means, a deformable member carried by said plunger intermediate said flange and said shoulder and normally spaced from and overlying the intermediate portion of said normally open conduit means, and means on the housing communicating with the bore to retain an explosive actuator for moving said plunger to force the deformable member against the shoulder and extrude a portion of the deformable member out of said bore into portions of the normally open conduit means for plugging the same and to effect the opening of said normally closed conduit means by the plunger shearing edge substantially concomitantly with the plugging of the normally open conduit means.

  10. Explosive Contagion in Networks

    Science.gov (United States)

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

    2016-01-01

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

  11. Furball Explosive Breakout Test

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-08-05

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

  12. Disaster management following explosion.

    Science.gov (United States)

    Sharma, B R

    2008-01-01

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

  13. The Cambrian explosion.

    Science.gov (United States)

    Briggs, Derek E G

    2015-10-01

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

  14. Suppression of stratified explosive interactions

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-01-01

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

  15. Explosive Blast Neuropathology and Seizures

    Directory of Open Access Journals (Sweden)

    S. Krisztian eKovacs

    2014-04-01

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

  16. Explosive plane-wave lens

    Science.gov (United States)

    Marsh, Stanley P.

    1988-01-01

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

  17. Explosive Spot Joining of Metals

    Science.gov (United States)

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

    1997-01-01

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

  18. Phenomenological modelling of steam explosions

    International Nuclear Information System (INIS)

    During a hypothetical core meltdown accident, an important safety issue to be addressed is the potential for steam explosions. This paper presents analysis and modelling of experimental results. There are four observations that can be drawn from the analysis: (1) vapor explosions are suppressed by noncondensible gases generated by fuel oxidation, by high ambient pressure, and by high water temperatures; (2) these effects appear to be trigger-related in that an explosion can again be induced in some cases by increasing the trigger magnitude; (3) direct fuel liquid-coolant liquid contact can explain small scale fuel fragmentation; (4) heat transfer during the expansion phase of the explosion can reduce the work potential

  19. Nuclear explosions for peaceful purposes

    International Nuclear Information System (INIS)

    Theoretical and technological aspects as well as peaceful applications of nuclear explosions are discussed emphasizing on contained and cratering explosions. For both types of explosions phenomenology as well as the dimensions of cavity and chimney or of the crater and their predictability are described. As regards applications engineering applications, e.g., canal and harbour construction, industrial applications, e.g., oil reservoir stimulation, oil shale recovery, natural gas stimulation and storage, in-site mineral recovery, and scientific applications, e.g., in neutron physics and geophysics, are dealt with. Safety aspects are discussed considering air-blast effects, soil movement and radiological effects depending on the two types of explosions. Finally, several national programs are outlined

  20. Explosion modelling for complex geometries

    Science.gov (United States)

    Nehzat, Naser

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

  1. Simulation Analysis of Indoor Gas Explosion Damage

    Institute of Scientific and Technical Information of China (English)

    钱新明; 陈林顺; 冯长根

    2003-01-01

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

  2. Microbial remediation of explosive waste.

    Science.gov (United States)

    Singh, Baljinder; Kaur, Jagdeep; Singh, Kashmir

    2012-05-01

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

  3. Tagging of Explosives for Detection

    Directory of Open Access Journals (Sweden)

    J. S. Gharia

    2000-01-01

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

  4. Explosive Characteristics of Carbonaceous Nanoparticles

    Science.gov (United States)

    Turkevich, Leonid; Fernback, Joseph; Dastidar, Ashok

    2013-03-01

    Explosion testing has been performed on 20 codes of carbonaceous particles. These include SWCNTs (single-walled carbon nanotubes), MWCNTs (multi-walled carbon nanotubes), CNFs (carbon nanofibers), graphene, diamond, fullerene, carbon blacks and graphites. Explosion screening was performed in a 20 L explosion chamber (ASTM E1226-10 protocol), at a (dilute) concentration of 500 g/m3, using a 5 kJ ignition source. Time traces of overpressure were recorded. Samples exhibited overpressures of 5-7 bar, and deflagration index KSt = V1/3 (dp/pt)max ~ 10 - 80 bar-m/s, which places these materials in European Dust Explosion Class St-1 (similar to cotton and wood dust). There was minimal variation between these different materials. The explosive characteristics of these carbonaceous powders are uncorrelated with particle size (BET specific surface area). Additional tests were performed on selected materials to identify minimum explosive concentration [MEC]. These materials exhibit MEC ~ 101 -102 g/m3 (lower than the MEC for coals). The concentration scans confirm that the earlier screening was performed under fuel-rich conditions (i.e. the maximum over-pressure and deflagration index exceed the screening values); e.g. the true fullerene KSt ~ 200 bar-m/s, placing it borderline St-1/St-2. Work supported through the NIOSH Nanotechnology Research Center (NTRC)

  5. Hydrocarbon production with nuclear explosives

    International Nuclear Information System (INIS)

    The tremendous energy of nuclear explosives and the small dimensions of the explosive package make an ideal combination for drill-hole explosive emplacement in deep, thick hydrocarbon deposits. Potential applications exist in fracturing low permeability natural-gas and petroleum formations for stimulating production, fracturing oil shale to permit in situ retorting, and creating storage chimneys for natural gas, liquefied petroleum gas, petroleum, petroleum products, helium, and other fluids. Calculations show, for example, that less than 100 shots per year would be needed to stabilize the natural gas reserves to production ratio. Under the Government-industry Plowshare program, two experiments, Projects Gasbuggy and Rulison, were conducted to stimulate natural gas production from low-permeability formations. Incomplete information indicates that both were technically successful. Potential problems associated with the use of nuclear explosives for underground engineering applications are radioactive contamination, maximum yield limitations, high costs of detonating contained nuclear explosives, and adverse public opinion. Results at Project Gasbuggy and other considerations indicated that the problem of radioactive contamination was about as predicted and not an insurmountable one. Also, it was demonstrated that shots at adequate depths could be detonated without appreciable damage to existing surface and subsurface buildings, natural features, and equipment. However, costs must be reduced and the public must be better informed before these techniques can be widely used in field operations. On the basis of present knowledge, the potential of nuclear-explosive stimulation of hydrocarbon production appears good. Additional field experiments will be required to adequately explore that potential. (author)

  6. Delayed signatures of underground nuclear explosions

    Science.gov (United States)

    Carrigan, Charles R.; Sun, Yunwei; Hunter, Steven L.; Ruddle, David G.; Wagoner, Jeffrey L.; Myers, Katherine B. L.; Emer, Dudley F.; Drellack, Sigmund L.; Chipman, Veraun D.

    2016-01-01

    Radionuclide signals from underground nuclear explosions (UNEs) are strongly influenced by the surrounding hydrogeologic regime. One effect of containment is delay of detonation-produced radioxenon reaching the surface as well as lengthening of its period of detectability compared to uncontained explosions. Using a field-scale tracer experiment, we evaluate important transport properties of a former UNE site. We observe the character of signals at the surface due to the migration of gases from the post-detonation chimney under realistic transport conditions. Background radon signals are found to be highly responsive to cavity pressurization suggesting that large local radon anomalies may be an indicator of a clandestine UNE. Computer simulations, using transport properties obtained from the experiment, track radioxenon isotopes in the chimney and their migration to the surface. They show that the chimney surrounded by a fractured containment regime behaves as a leaky chemical reactor regarding its effect on isotopic evolution introducing a dependence on nuclear yield not previously considered. This evolutionary model for radioxenon isotopes is validated by atmospheric observations of radioxenon from a 2013 UNE in the Democratic People’s Republic of Korea (DPRK). Our model produces results similar to isotopic observations with nuclear yields being comparable to seismic estimates. PMID:26979288

  7. Delayed signatures of underground nuclear explosions

    Science.gov (United States)

    Carrigan, Charles R.; Sun, Yunwei; Hunter, Steven L.; Ruddle, David G.; Wagoner, Jeffrey L.; Myers, Katherine B. L.; Emer, Dudley F.; Drellack, Sigmund L.; Chipman, Veraun D.

    2016-03-01

    Radionuclide signals from underground nuclear explosions (UNEs) are strongly influenced by the surrounding hydrogeologic regime. One effect of containment is delay of detonation-produced radioxenon reaching the surface as well as lengthening of its period of detectability compared to uncontained explosions. Using a field-scale tracer experiment, we evaluate important transport properties of a former UNE site. We observe the character of signals at the surface due to the migration of gases from the post-detonation chimney under realistic transport conditions. Background radon signals are found to be highly responsive to cavity pressurization suggesting that large local radon anomalies may be an indicator of a clandestine UNE. Computer simulations, using transport properties obtained from the experiment, track radioxenon isotopes in the chimney and their migration to the surface. They show that the chimney surrounded by a fractured containment regime behaves as a leaky chemical reactor regarding its effect on isotopic evolution introducing a dependence on nuclear yield not previously considered. This evolutionary model for radioxenon isotopes is validated by atmospheric observations of radioxenon from a 2013 UNE in the Democratic People’s Republic of Korea (DPRK). Our model produces results similar to isotopic observations with nuclear yields being comparable to seismic estimates.

  8. Explosion of lithium-thionyl-chloride battery due to presence of lithium nitride

    OpenAIRE

    Hennesø, E.; Hedlund, Frank Huess

    2015-01-01

    An explosion of a lithium–thionyl-chloride (Li–SOCl2) battery during production (assembly) leads to serious worker injury. The accident cell batch had been in a dry-air intermediate storage room for months before being readied with thionyl chloride electrolyte. Metallic lithium can react with atmospheric nitrogen to produce lithium nitride. Nodules of lithium nitride were found to be present on the lithium foil in other cells of the accident batch. The investigation attributed the explosion t...

  9. 76 FR 64974 - Commerce in Explosives; List of Explosive Materials (2011R-18T)

    Science.gov (United States)

    2011-10-19

    ... Explosive Materials dated November 17, 2010 (Docket No. ATF 42N, 75 FR 70291). Notice of List of Explosive... tetrazene hydrate]. Tetrazole explosives. Tetryl . Tetrytol. Thickened inorganic oxidizer salt...

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

    Institute of Scientific and Technical Information of China (English)

    林柏泉; 周世宁; 张仁贵

    1998-01-01

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

  11. Safe explosives for shaped charges

    International Nuclear Information System (INIS)

    It was demonstrated that high-performance shaped charges could be developed using as the explosive charge mixtures of ingredients that are not, by themselves, considered explosives. At least one of the ingredients needed to be a liquid, stored separately, that could be quickly injected into the shaped charge cavity to generate the active explosive. Precision copper shaped charge cones in diameters of 65.2, 83.8, and 100.2 mm (about 2.6, 3.3, and 4.0 in.) were obtained and appropriate hardware was fabricated. It was demonstrated that 4 cone diameters of penetration were obtained in 255 BHN armor plate steel if the explosive charge was nitromethane or a combination of fine crystalline ammonium nitrate at a density of 1.0 Mg/m3 with nitromethane. However, when prilled ammonium nitrate was used with nitromethane, the jet failed to form. The shaped charges would be used to destroy the high explosive in a nuclear warhead in case of imminent enemy threat to the weapon

  12. Shock Initiation of Heterogeneous Explosives

    International Nuclear Information System (INIS)

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

  13. Explosion limits for combustible gases

    Institute of Scientific and Technical Information of China (English)

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

    2009-01-01

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

  14. The Quiet Explosion

    Science.gov (United States)

    2008-07-01

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

  15. Coulomb explosion of "hot spot"

    CERN Document Server

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

    2016-01-01

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

  16. Evidence for Nearby Supernova Explosions

    CERN Document Server

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

    2002-01-01

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

  17. Optimal dynamic detection of explosives

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-01-01

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

  18. Seismic coupling of nuclear explosions

    International Nuclear Information System (INIS)

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

  19. Numerical simulation of the ionization effects of low- and high-altitude nuclear explosions

    International Nuclear Information System (INIS)

    Low-altitude and high-altitude nuclear explosions are sources of intensive additional ionization in ionosphere. In this paper, in terms of the ionization equilibrium equation system and the equation of energy deposition of radiation in atmosphere, and considering the influence of atmosphere, the temporal and spatial distribution of ionization effects caused by atmospheric nuclear detonation are investigated. The calculated results show that the maximum of additional free electron density produced by low-altitude nuclear explosion is greater than that by the high-altitude nuclear burst. As to the influence of instant nuclear radiation, there is obvious difference between the low-altitude and the high-altitude explosions. The influence range and the continuance time caused by delayed nuclear radiation is less for the low-altitude nuclear detonation than that for the high-altitude one. (authors)

  20. ICPP custom dissolver explosion recovery

    International Nuclear Information System (INIS)

    This report discusses the recovery from the February 9, 1991 small scale explosion in a custom processing dissolver at the Idaho Chemical Processing Plant. Custom processing is a small scale dissolution facility which processes nuclear material in an economical fashion. The material dissolved in this facility was uranium metal, uranium oxides, and uranium/fissium alloy in nitric acid. The paper explained the release of fission material, and the decontamination and recovery of the fuel material. The safety and protection procedures were also discussed. Also described was the chemical analysis which was used to speculate the most probable cause of the explosion. (MB)

  1. Explosive coalescence of magnetic islands

    Science.gov (United States)

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

    1986-01-01

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

  2. System for detecting nuclear explosions

    International Nuclear Information System (INIS)

    Apparatus for detecting underground nuclear explosions is described that is comprised of an antenna located in the dielectric substance of a deep waveguide in the earth and adapted to detect low frequency electromagnetic waves generated by a nuclear explosion, the deep waveguide comprising the high conductivity upper sedimentary layers of the earth, the dielectric basement rock, and a high conductivity layer of basement rock due to the increased temperature thereof at great depths, and means for receiving the electromagnetic waves detected by said antenna means

  3. On The Explosion Geometry of Red Supergiant Stars

    Science.gov (United States)

    Leonard, Douglas C.; Supernova Spectropolarimetry Project (SNSPOL)

    2016-06-01

    From progenitor studies, type II-Plateau supernovae (SNe II-P) have been decisively and uniquely determined to arise from isolated red supergiant (RSG) stars, establishing the most homogeneous --- and well understood --- progenitor class of any type of core-collapse supernova. The physical process by which these stars explode, however, remains a mystery. A fundamental clue to the nature of the explosion mechanism is explosion geometry: In short, are supernovae round? Because young supernova atmospheres are electron-scattering dominated, their net linear polarization provides a direct probe of early-time supernova geometry, with higher degrees of polarization generally indicating greater departures from spherical symmetry. This presentation will describe the ongoing work being carried out on RSG explosion geometry by the SuperNova SpectroPOLarimetry project (SNSPOL), with a particular focus on SN 2013ej -- an SN II-P that exhibited remarkably high polarization just days after the explosion, and for which twelve epochs of spectropolarimetry trace an intriguing tale about its geometry deep into the nebular phase.We acknowledge support from NSF grants AST-1009571 and AST-1210311, under which part of this research was carried out.

  4. Lead-free primary explosives

    Science.gov (United States)

    Huynh, My Hang V.

    2010-06-22

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

  5. Explosion mitigation by water mist

    NARCIS (Netherlands)

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

    2010-01-01

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

  6. Explosion-proof scintillation counter

    International Nuclear Information System (INIS)

    It is noted that measuring devices used in the research works conducted with the help of radioactive isotopes on the chemical industry installations dangerous from the point of view of explosions, especially on the installations of the petrochemistry industry, must not limit the exploitation safety of these installations. The said especially concerns with the Geiger-Mueller type counters and scintillation detectors, located immediately in the places of measurements on the installations and supplied by high voltage power supply. It has been shown that electronic circuits for the detector's signals processing and obtaining working voltages can be located out of the explosive dangerous premices, for example, in the car trailer. Description is given of the device, with the help of which explosion safety is provided for the serially produced scintillation counter with forced ventilation (counter of the VA-S-50 type). Due to this device application, the exploitation parameters of the counter do not go down and there is no need for any changes in its design. Description is given of the device for external power supply and control of the counter which can swich off the power supply in the case of an accident, dangerous from the point of view of violation of the explosion safety conditions. The device is described for providing service to 10 measuring chanels, mounted on the car trailer

  7. Experimental approach to explosive nucleosynthesis

    International Nuclear Information System (INIS)

    Recent development of experimental studies on explosive nucleosynthesis, especially the rapid proton process and the primordial nucleosynthesis were discussed with a stress on unstable nuclei. New development in the experimental methods for the nuclear astrophysics is also discussed which use unstable nuclear beams. (author)

  8. Excavation research with chemical explosives

    International Nuclear Information System (INIS)

    The US Army Engineer Nuclear Cratering Group (NCG) is located at the Lawrence Radiation Laboratory in Livermore, California. NCG was established in 1962 and assigned responsibility for technical program direction of the Corps of Engineers Nuclear Excavation Research Program. The major part of the experimental program has been the execution of chemical explosive excavation experiments. In the past these experiments were preliminary to planned nuclear excavation experiments. The experience gained and technology developed in accomplishing these experiments has led to an expansion of NCG's research mission. The overall research and development mission now includes the development of chemical explosive excavation technology to enable the Corps of Engineers to more economically accomplish Civil Works Construction projects of intermediate size. The current and future chemical explosive excavation experiments conducted by NCG will be planned so as to provide data that can be used in the development of both chemical and nuclear excavation technology. In addition, whenever possible, the experiments will be conducted at the specific sites of authorized Civil Works Construction Projects and will be designed to provide a useful portion of the engineering structures planned in that project. Currently, the emphasis in the chemical explosive excavation program is on the development of design techniques for producing specific crater geometries in a variety of media. Preliminary results of two such experiments are described in this paper; Project Pre-GONDOLA III, Phase III, Reservoir Connection Experiment; and a Safety Calibration Series for Project TUGBOAT, a small boat harbor excavation experiment

  9. Turbulent Combustion in SDF Explosions

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-11-12

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

  10. Underground nuclear explosions and earthquakes

    International Nuclear Information System (INIS)

    The stages that have marked the ways towards the interdiction of nuclear tests are reviewed. Although seismographic equipments have been greatly improved, it is shown that a separate detection of underground nuclear explosions from natural seismic vibrations is still quite uneasy. The use of nuclear loads for civil engineering still makes it more complicate to apply a treatee of interdiction of nuclear tests

  11. Episodic Explosions in Interstellar Ices

    CERN Document Server

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

    2013-01-01

    We present a model for the formation of large organic molecules in dark clouds. The molecules are produced in the high density gas-phase that exists immediately after ice mantles are explosively sublimated. The explosions are initiated by the catastrophic recombination of trapped atomic hydrogen. We propose that, in molecular clouds, the processes of freeze-out onto ice mantles, accumulation of radicals, explosion and then rapid (three-body) gas-phase chemistry occurs in a cyclic fashion. This can lead to a cumulative molecular enrichment of the interstellar medium. A model of the time-dependent chemistries, based on this hypothesis, shows that significant abundances of large molecular species can be formed, although the complexity of the species is limited by the short expansion timescale in the gas, immediately following mantle explosion. We find that this mechanism may be an important source of smaller organic species, such as methanol and formaldehyde, as well as precursors to bio-molecule formation. Most...

  12. Spectral Signatures of Gravitationally Confined Thermonuclear Supernova Explosions

    Science.gov (United States)

    Kasen, Daniel; Plewa, Tomasz

    2005-03-01

    We consider some of the spectral and polarimetric signatures of the gravitationally confined detonation scenario for Type Ia supernova explosions. In this model, material produced by an off-center deflagration (which itself fails to produce the explosion) forms a metal-rich atmosphere above the white dwarf surface. Using hydrodynamical simulations, we show that this atmosphere is compressed and accelerated during the subsequent interaction with the supernova ejecta. This leads ultimately to the formation of a high-velocity pancake of metal-rich material that is geometrically detached from the bulk of the ejecta. When observed at the epochs near maximum light, this absorbing pancake produces a highly blueshifted and polarized calcium IR triplet absorption feature similar to that observed in several Type Ia supernovae. We discuss the orientation effects present in our model and contrast them to those expected in other supernova explosion models. We propose that a large sample of spectropolarimetric observations can be used to critically evaluate the different theoretical scenarios.

  13. Statistical estimation of loads from gas explosions

    OpenAIRE

    Høiset, Stian

    1998-01-01

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

  14. 14 CFR 420.63 - Explosive siting.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Explosive siting. 420.63 Section 420.63... TRANSPORTATION LICENSING LICENSE TO OPERATE A LAUNCH SITE Responsibilities of a Licensee § 420.63 Explosive... the configuration of the launch site is in accordance with an explosive site plan, and that...

  15. 46 CFR 188.10-25 - Explosive.

    Science.gov (United States)

    2010-10-01

    ... release of gas and heat. Explosives are discussed in more detail in 49 CFR parts 171-179. ... 46 Shipping 7 2010-10-01 2010-10-01 false Explosive. 188.10-25 Section 188.10-25 Shipping COAST... Definition of Terms Used in This Subchapter § 188.10-25 Explosive. This term means a chemical compound...

  16. 33 CFR 401.67 - Explosive vessels.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Explosive vessels. 401.67 Section... 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...

  17. Merging Infrasound and Electromagnetic Signals as a Means for Nuclear Explosion Detection

    Science.gov (United States)

    Ashkenazy, Joseph; Lipshtat, Azi; Kesar, Amit S.; Pistinner, Shlomo; Ben Horin, Yochai

    2016-04-01

    The infrasound monitoring network of the CTBT consists of 60 stations. These stations are capable of detecting atmospheric events, and may provide approximate location within time scale of a few hours. However, the nature of these events cannot be deduced from the infrasound signal. More than two decades ago it was proposed to use the electromagnetic pulse (EMP) as a means of discriminating nuclear explosion from other atmospheric events. An EMP is a unique signature of nuclear explosion and is not detected from chemical ones. Nevertheless, it was decided to exclude the EMP technology from the official CTBT verification regime, mainly because of the risk of high false alarm rate, due to lightning electromagnetic pulses [1]. Here we present a method of integrating the information retrieved from the infrasound system with the EMP signal which enables us to discriminate between lightning discharges and nuclear explosions. Furthermore, we show how spectral and other characteristics of the electromagnetic signal emitted from a nuclear explosion are distinguished from those of lightning discharge. We estimate the false alarm probability of detecting a lightning discharge from a given area of the infrasound event, and identifying it as a signature of a nuclear explosion. We show that this probability is very low and conclude that the combination of infrasound monitoring and EMP spectral analysis may produce a reliable method for identifying nuclear explosions. [1] R. Johnson, Unfinished Business: The Negotiation of the CTBT and the End of Nuclear Testing, United Nations Institute for Disarmament Research, 2009.

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

    Institute of Scientific and Technical Information of China (English)

    李守巨; 刘迎曦; 何翔; 周圆π

    2001-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2001-01-01

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

  20. Propagation of acoustic gravity waves excited by explosions

    International Nuclear Information System (INIS)

    Acoustic gravity waves excited by low-altitude nuclear explosions have been observed in the ionosphere, by H.F. Doppler soundings, at horizontal distances from the source between 100 and 1200 km. The characteristics of the initial shock wave, which is observed at short range, are progressively replaced by those of the atmospheric wave guide. In particular, the dispersion properties of the signal observed in the ionosphere at long range are those of the first acoustic and gravity modes. Detailed study of the propagation times to middle and long range shows that the wave guide is mainly excited by the focalisation of acoustic energy which is produced by non-linear mechanisms at an altitude of about 100 km and at a small horizontal distance from the explosion

  1. 27 CFR 555.205 - Movement of explosive materials.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Movement of explosive..., FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Storage § 555.205 Movement of explosive materials. All explosive materials must be kept in locked magazines meeting...

  2. 27 CFR 555.32 - Special explosive devices.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Special explosive devices..., AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Administrative and Miscellaneous Provisions § 555.32 Special explosive devices. The Director may exempt certain explosive...

  3. Seeing a Stellar Explosion in 3D

    Science.gov (United States)

    2010-08-01

    faster in some directions than others, leading to an irregular shape with some parts stretching out further into space. The first material to be ejected from the explosion travelled at an incredible 100 million km per hour, which is about a tenth of the speed of light or around 100 000 times faster than a passenger jet. Even at this breakneck speed it has taken 10 years to reach a previously existing ring of gas and dust puffed out from the dying star. The images also demonstrate that another wave of material is travelling ten times more slowly and is being heated by radioactive elements created in the explosion. "We have established the velocity distribution of the inner ejecta of Supernova 1987A," says lead author Karina Kjær. "Just how a supernova explodes is not very well understood, but the way the star exploded is imprinted on this inner material. We can see that this material was not ejected symmetrically in all directions, but rather seems to have had a preferred direction. Besides, this direction is different to what was expected from the position of the ring." Such asymmetric behaviour was predicted by some of the most recent computer models of supernovae, which found that large-scale instabilities take place during the explosion. The new observations are thus the first direct confirmation of such models. SINFONI is the leading instrument of its kind, and only the level of detail it affords allowed the team to draw their conclusions. Advanced adaptive optics systems counteracted the blurring effects of the Earth's atmosphere while a technique called integral field spectroscopy allowed the astronomers to study several parts of the supernova's chaotic core simultaneously, leading to the build-up of the 3D image. "Integral field spectroscopy is a special technique where for each pixel we get information about the nature and velocity of the gas," says Kjær. "This means that besides the normal picture we also have the velocity along the line of sight. Because we

  4. Fast neutron activation measurement of concealed explosives

    International Nuclear Information System (INIS)

    Spectra of 0.511 MeV γ-ray of nitrogen and 6.13 MeV γ-ray of oxygen and their ratio are measured by using two neutron sourses of different yield for explosive or non-explosive materials. Sensitivity and detecting speed are determined. A planar distribution of the explosive or non-explosive materials with different contents of nitrogen and oxygen is given. The whole design and security of detection method of fast neutron activation analysis system is discussed for concealed explosives

  5. Application of blast wave theory to explosive propulsion. [system performance analysis

    Science.gov (United States)

    Back, L. H.

    1975-01-01

    An analysis was carried out by using blast wave theory to delineate the important aspects of detonating explosives in nozzles, such as flow and wave phenomena, characteristic length and time scales, and the parameters on which the specific impulse is dependent. The propulsive system utilizes the momentum of the ambient gas set into motion in the nozzle by the explosion. A somewhat simplified model was considered for the situation where the mass of ambient gas in the nozzle is much greater than the mass of gas produced in the explosion, a condition of interest for dense atmospheres, e.g., near the surface of Venus. Instantaneous detonation and energy release was presumed to occur at the apex of a conical nozzle, and the shock wave generated by the explosion was taken to propagate as a spherical wave, thereby setting the ambient gas in the nozzle into one-dimensional radially outward motion.

  6. UTEX modeling of xenon signature sensitivity to geology and explosion cavity characteristics following an underground nuclear explosion

    Science.gov (United States)

    Lowrey, J. D.; Haas, D.

    2013-12-01

    Underground nuclear explosions (UNEs) produce anthropogenic isotopes that can potentially be used in the verification component of the Comprehensive Nuclear-Test-Ban Treaty. Several isotopes of radioactive xenon gas have been identified as radionuclides of interest within the International Monitoring System (IMS) and in an On-Site Inspection (OSI). Substantial research has been previously undertaken to characterize the geologic and atmospheric mechanisms that can drive the movement of radionuclide gas from a well-contained UNE, considering both sensitivities on gas arrival time and signature variability of xenon due to the nature of subsurface transport. This work further considers sensitivities of radioxenon gas arrival time and signatures to large variability in geologic stratification and generalized explosion cavity characteristics, as well as compares this influence to variability in the shallow surface.

  7. 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;

    2009-01-01

    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...... of different types of conceivable contaminants from a ‘dirty bomb’ are discussed....

  8. Atmospheric contamination

    International Nuclear Information System (INIS)

    It is about the levels of contamination in center America, the population's perception on the problem, effects of the atmospheric contamination, effects in the environment, causes of the atmospheric contamination, possibilities to reduce the atmospheric contamination and list of Roeco Swisscontac in atmospheric contamination

  9. Spot test kit for explosives detection

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-03-11

    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.

  10. Hazards of explosives dusts: Particle size effects

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-02-01

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

  11. Underwater explosions and cavitation phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Kamegai, M.

    1979-08-28

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

  12. Underwater explosions and cavitation phenomena

    International Nuclear Information System (INIS)

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

  13. Waves from an underground explosion

    Science.gov (United States)

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

    1984-05-01

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

  14. Explosive shielding by weak layers

    International Nuclear Information System (INIS)

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

  15. Nuclear explosions and their effects

    International Nuclear Information System (INIS)

    Nuclear weapons of all kinds and forms are a threat to mankind and earth due to the destruction, devastation and death resulting from them. The nuclear reactors and atomic power stations present in the world today will never be fully safe and secured, but it can be made safer in the future by constructing a new generation of nuclear reactors, relying on the auto security system. The article shows the different effects resulting from nuclear explosions. (author)

  16. Explosive Formulation Code Naming SOP

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-09-19

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

  17. Causes of the Cambrian Explosion.

    OpenAIRE

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

    2013-01-01

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

  18. Nuclear Explosions 1945-1998

    International Nuclear Information System (INIS)

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

  19. Thermodynamic States in Explosion Fields

    Energy Technology Data Exchange (ETDEWEB)

    Kuhl, A L

    2010-03-12

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

  20. Nuclear Explosions 1945-1998

    Energy Technology Data Exchange (ETDEWEB)

    Bergkvist, Nils-Olov; Ferm, Ragnhild

    2000-07-01

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

  1. Seismic discrimination of nuclear explosions

    International Nuclear Information System (INIS)

    The monitoring of underground nuclear explosions has been discussed for over 30 years in connection with verification of test ban treaties, and monitoring is also one of the basic ways to learn about nuclear weapons development in different countries. Explosion monitoring is thus an important technical exercise, occasionally attracting attention for high-level policymakers and generating front page news. The underlying issues here are related to the uses of nuclear weapons, their cost, and the strategic capabilities and vulnerabilities of the superpowers and other countries. Because these are some of the largest and most contentious questions of our time, arguments sometimes spill over from the policy arena into the technical subject of monitoring capability itself. As a side effect of the debate, geophysics (especially seismology) continues to be shaped by significant funding for research and development in verification/monitoring technologies. New funds at the level of about $30 million came into seismic monitoring programs in the United States in 1989. In this paper, the authors review the history of nuclear testing and test ban negotiations, introduce some basic terminology, give examples of detection capability, describe characteristics of different seismic sources and methods of explosion identification, and briefly review different evasion scenarios. The authors conclude with a summary statement of identification capability and its implication for future possibilities in verifying new nuclear testing limitations

  2. Fish kill from underwater explosions

    Science.gov (United States)

    Stuart, David J.

    1962-01-01

    The U.S. Geological Survey has used 23 different shotpoints during two seasons of field work in our seismic study of crustal structure in western United States. Without exception, it has been found that under-water shotpoints result in a more efficient conversion of explosive energy into seismic energy than do drilled-hole shotpoints. This experience, together with elimination of drilling costs, has led to the use of underwater shotpoints wherever possible. Three of the 23 shotpoints were in the Pacific Ocean, and for these we have no detailed information on the fish kill. Another six shotpoints were located in inland bodies of water. These are: * Soda Lake near Fallon, Nevada * Mono Lake near Lee Vining, California * Lake Mead near Boulder City, Nevada * Shasta Lake near Redding, California * C.J. Strike Reservoir near Bruneau, Idaho * Lucky Peak Reservoir near Boise, Idaho The 22 high-explosive charges, weighing a total of 95,100 pounds, that were fired in lakes containing fish life resulted in the known death of 2,413 game fish with a total weight of 759 pounds. The average mortality was 110 game fish or 34.5 pounds of game fish killed per average shot of 4,325 pounds of high-explosives.

  3. Antropogen contamination of the earth atmosphere

    International Nuclear Information System (INIS)

    Among the antropogen contamination sources of the earth atmosphere the total beta activity of rain water, carbon 14 activity according to the annual rings of trees and the krypton 85 activity of the air were determined systematically for several years in Hungary. The data of aerial contamination due to atmospheric nuclear explosions and to the impact of nuclear facilities especially nuclear power plants and fuel reprocessing plants are discussed and demonstrated in graphs. (V.N.) 12 refs.; 7 figs

  4. The acoustic field in the ionosphere caused by an underground nuclear explosion

    Science.gov (United States)

    Krasnov, V. M.; Drobzheva, Ya. V.

    2005-07-01

    The problem of describing the generation and propagation of an infrasonic wave emitted by a finite extended source in the inhomogeneous absorbing atmosphere is the focus of this paper. It is of interest since the role of infrasonic waves in the energy balance of the upper atmosphere remains largely unknown. We present an algorithm, which allows adaptation of a point source model for calculating the infrasonic field from an underground nuclear explosion at ionospheric altitudes. Our calculations appear to agree remarkably well with HF Doppler sounding data measured for underground nuclear explosions at the Semipalatinsk Test Site. We show that the temperature and ionospheric electron density perturbation caused by an acoustic wave from underground nuclear explosion can reach 10% of background levels.

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

    Data.gov (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)...

  6. Cavity pressure history of contained nuclear explosions

    International Nuclear Information System (INIS)

    Knowledge of pressure in cavities created by contained nuclear explosions is useful for estimating the possibility of venting radioactive debris to the atmosphere. Measurements of cavity pressure, or temperature, would be helpful in evaluating the correctness of present code predictions of underground explosions. In instrumenting and interpreting such measurements it is necessary to have good theoretical estimates of cavity pressures. In this paper cavity pressure is estimated at the time when cavity growth is complete. Its subsequent decrease due to heat loss from the cavity to the surrounding media is also predicted. The starting pressure (the pressure at the end of cavity growth) is obtained by adiabatic expansion to the final cavity size of the vaporized rock gas sphere created by the explosion. Estimates of cavity size can be obtained by stress propagation computer codes, such as SOC and TENSOR. However, such estimates require considerable time and effort. In this paper, cavity size is estimated using a scheme involving simple hand calculations. The prediction is complicated by uncertainties in the knowledge of silica water system chemistry and a lack of information concerning possible blowoff of wall material during cavity growth. If wall material blows off, it can significantly change the water content in the cavity, compared to the water content in the ambient media. After cavity growth is complete, the pressure will change because of heat loss to the surrounding media. Heat transfer by convection, radiation and conduction is considered, and its effect on the pressure is calculated. Analysis of cavity heat transfer is made difficult by the complex nature of processes which occur at the wall where melting, vaporization and condensation of the gaseous rock can all occur. Furthermore, the melted wall material could be removed by flowing or dripping to the cavity floor. It could also be removed by expansion of the steam contained in the melt (blowoff) and by

  7. Ionospheric disturbances due to underground nuclear explosions and other sources: an elementary discussion, Part I

    International Nuclear Information System (INIS)

    The possible effect of verticle ground surface motion on the ionosphere, as a consequence of acoustic propagation, is discussed. Estimates of R. F. phase path perturbations are developed for several representative sources and several propagative modes (both terrestrial and atmospheric). In particular, amplitude models for ionospheric density perturbations are used. The discrimination of earth quakes and nuclear explosive disturbances is considered and some detailed properties of the extended atmosphere are described. A list of references is provided. (U.S.)

  8. Explosion protection in nuclear power plants equipped with LWRs (general and case-specific requirements). Draft. Publication 6/00

    International Nuclear Information System (INIS)

    The KTA draft safety code, KTA 2103, applies to nuclear power plants equipped with light-water reactors. The draft specifies general requirements for ensuring safe functioning and protection of safety components from hazards emanating from substances transported to the site or on site, or that can penetrate into the site, or can form on site, and build up an explosive atmosphere or other explosive mixtures. The draft safety code does not apply to protective measures against hazards of explosions induced by: (a) the handling of materials covered by the Explosives Act, (SprengG), sub-section 1 of section 1; (b) handling of explosive materials off the power plant site; (c) accidentally released hydrogen (LOCAs in LWRs, radiolysis); (d) gaseous wastes from power plant operation; (e) diesel engines on site. (orig./CB)

  9. Crisis behaviour of the reactive recoil of a water jets under conditions of explosive boiling

    International Nuclear Information System (INIS)

    One presents the measurement results of the reactive force of boiling up water jet flowing through short channel into the atmosphere depending on superheating degree and at various evaporation mechanisms. The intensive fluctuation evaporation of water (explosive boiling) and presence of a plane perpendicular to the channel axis are shown to result in abrupt reduction of the reactive recoil value

  10. Explosion of lithium-thionyl-chloride battery due to presence of lithium nitride

    DEFF Research Database (Denmark)

    Hennesø, E.; Hedlund, Frank Huess

    2015-01-01

    atmospheric nitrogen to produce lithium nitride. Nodules of lithium nitride were found to be present on the lithium foil in other cells of the accident batch. The investigation attributed the explosion to the formation of porous lithium nitride during intermediate storage and a violent exothermal...

  11. Data base of chemical explosions in Kazakhstan

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-01

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

  12. Modelling of an explosive event observed by SUMER & TRACE

    Science.gov (United States)

    Price, Daniel; Taroyan, Youra; Ishak, Bebe

    2016-07-01

    To fully understand coronal heating, we must first understand the different solar processes that move energy throughout the solar atmosphere. TRACE observations have revealed a short cold loop evolving over a small timescale, seemingly with multiple explosive events occurring along its length. An adaptive hydrodynamic radiation code was used to simulate the loop under non-equilibrium ionization. Footpoint heating and cold plasma injection were considered as possible scenarios to reproduce the observations. The simulation results were converted into synthetic observations through forward modelling, for comparison to SOHO/SUMER spectral observations of the loop.

  13. The CTBT Verification Regime: Monitoring the Earth for nuclear explosions

    International Nuclear Information System (INIS)

    The Comprehensive nuclear-Test-Ban Treaty (CTBT) bans all nuclear weapon tests. Its unique verification regime is designed to detect nuclear explosions anywhere on the planet - in the oceans, underground and in the atmosphere. once complete, the international Monitoring system (iMs) will consist of 337 facilities located in 89 countries around the globe. The iMs is currently operating in test mode so that data are already transmitted for analysis from monitoring facilities to the international Data Centre (iDC) at the headquarters of the preparatory Commission for the Comprehensive nuclear-Test-Ban Treaty Organization (CTBTO) in Vienna. Data and analysis results are shared with Member states.

  14. Explosives Detection: Exploitation of the Physical Signatures

    Science.gov (United States)

    Atkinson, David

    2010-10-01

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

  15. Explosive Surface Hardening of Austenitic Stainless Steel

    Science.gov (United States)

    Kovacs-Coskun, T.

    2016-04-01

    In this study, the effects of explosion hardening on the microstructure and the hardness of austenitic stainless steel have been studied. The optimum explosion hardening technology of austenitic stainless steel was researched. In case of the explosive hardening used new idea mean indirect hardening setup. Austenitic stainless steels have high plasticity and can be easily cold formed. However, during cold processing the hardening phenomena always occurs. Upon the explosion impact, the deformation mechanism indicates a plastic deformation and this deformation induces a phase transformation (martensite). The explosion hardening enhances the mechanical properties of the material, includes the wear resistance and hardness. In case of indirect hardening as function of the setup parameters specifically the flayer plate position the hardening increased differently. It was find a relationship between the explosion hardening setup and the hardening level.

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

    Science.gov (United States)

    Sørensen, Annette; Teller, Philip J; Hilstrøm, Troels; Ahring, Birgitte K

    2008-09-01

    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. The combination of presoaking, wet explosion, and enzymatic hydrolysis was found to give the highest sugar yields. The use of atmospheric air gave the highest xylose yield (94.9% xylose, 61.3% glucose), while hydrogen peroxide gave the highest glucose yield (82.4% xylose, 63.7% glucose). PMID:18164954

  17. Explosion characteristics of synthesised biogas at various temperatures

    International Nuclear Information System (INIS)

    Biogas is considered as a valuable source of renewable energy. Indeed, it can be turned into useful energy (heat, electricity, fuel) and can contribute to reduce greenhouse gas emissions. Knowledge of its safety characteristics is a very important practical issue. Experimental investigation of synthesised biogas explosion characteristics was conducted in a 20-L sphere at various temperatures (30-70deg. C) and at atmospheric pressure. The studied biogas was made of 50% methane (CH4) and 50% carbon dioxide (CO2). It was also saturated with humidity: this composition is frequently met in digesters during waste methanisation. There are two inert gases in biogas: water vapour and carbon dioxide. Its vapour water content rises along with temperature. The presence of these inert gases modifies considerably biogas characteristics compared to the ones of pure methane: explosion limits are lowered and beyond 70deg. C, water vapour content is sufficient to inert the mixture. Furthermore, explosion violence (estimated with the maximum rate of pressure rise values (dp/dt)max) is three times lower for biogas than for pure methane at ambient temperature

  18. Explosion characteristics of synthesised biogas at various temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Dupont, L. [Institut National de l' Environnement Industriel et des Risques, Parc Technologique Alata, BP2, Verneuil-en-Halatte (France)]. E-mail: laurent.dupont@ineris.fr; Accorsi, A. [Institut National de l' Environnement Industriel et des Risques, Parc Technologique Alata, BP2, Verneuil-en-Halatte (France)]. E-mail: antoinette.accorsi@ineris.fr

    2006-08-25

    Biogas is considered as a valuable source of renewable energy. Indeed, it can be turned into useful energy (heat, electricity, fuel) and can contribute to reduce greenhouse gas emissions. Knowledge of its safety characteristics is a very important practical issue. Experimental investigation of synthesised biogas explosion characteristics was conducted in a 20-L sphere at various temperatures (30-70deg. C) and at atmospheric pressure. The studied biogas was made of 50% methane (CH{sub 4}) and 50% carbon dioxide (CO{sub 2}). It was also saturated with humidity: this composition is frequently met in digesters during waste methanisation. There are two inert gases in biogas: water vapour and carbon dioxide. Its vapour water content rises along with temperature. The presence of these inert gases modifies considerably biogas characteristics compared to the ones of pure methane: explosion limits are lowered and beyond 70deg. C, water vapour content is sufficient to inert the mixture. Furthermore, explosion violence (estimated with the maximum rate of pressure rise values (dp/dt){sub max}) is three times lower for biogas than for pure methane at ambient temperature.

  19. Stellar Explosions: Hydrodynamics and Nucleosynthesis

    Science.gov (United States)

    José, Jordi

    2015-12-01

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

  20. Explosive site percolation and finite size hysteresis

    OpenAIRE

    Bastas, Nikolaos; Kosmidis, Kosmas; Argyrakis, Panos

    2011-01-01

    We report the critical point for site percolation for the "explosive" type for 2D square lattices using Monte Carlo simulations and compare it to the classical well known percolation. We use similar algorithms as have been recently reported for bond percolation and networks. We calculate the "explosive" site percolation threshold as $p_c=0.695$ and we find evidence that "explosive" site percolation surprisingly may belong to a different universality class than bond percolation on lattices, pr...

  1. New Dark Matter Detector using Nanoscale Explosives

    OpenAIRE

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

    2014-01-01

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

  2. Analysis of TROI-13 Steam Explosion Experiment

    OpenAIRE

    Mitja Uršič; Matjaž Leskovar

    2008-01-01

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

  3. Is a Cambrian Explosion Coming for Robotics?

    OpenAIRE

    Gill A. Pratt

    2015-01-01

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

  4. The gas dynamics of explosions

    CERN Document Server

    Lee,\tJohn H S

    2016-01-01

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

  5. Explosive demolition of activated concrete

    International Nuclear Information System (INIS)

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

  6. 75 FR 1085 - Commerce in Explosives; List of Explosive Materials (2009R-18T)

    Science.gov (United States)

    2010-01-08

    ... 31, 2008 (Docket No. ATF 28N, 73 FR 80428). Notice of List of Explosive Materials Pursuant to 18 U.S... tetrazene hydrate]. Tetrazole explosives. Tetryl . Tetrytol. Thickened inorganic oxidizer salt...

  7. 75 FR 70291 - Commerce in Explosives; List of Explosive Materials (2010R-27T)

    Science.gov (United States)

    2010-11-17

    ..., 75 FR 1085). Notice of List of Explosive Materials Pursuant to 18 U.S.C. 841(d) and 27 CFR 555.23, I.... Tetrazene [tetracene, tetrazine, 1(5-tetrazolyl)-4-guanyl tetrazene hydrate]. Tetrazole explosives....

  8. 77 FR 58410 - Commerce in Explosives; List of Explosive Materials (2012R-10T)

    Science.gov (United States)

    2012-09-20

    ..., 76 FR 64974). Notice of List of Explosive Materials Pursuant to 18 U.S.C. 841(d) and 27 CFR 555.23, I.... Tetrazene [tetracene, tetrazine, 1(5-tetrazolyl)-4-guanyl tetrazene hydrate]. Tetrazole explosives....

  9. High Explosives Research and Development (HERD) Facility

    Data.gov (United States)

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

  10. Radiation techniques for detection of explosives

    International Nuclear Information System (INIS)

    The detection of explosive material in airport baggage requires a device that can quickly detect a small amount of explosives with a high success rate and a low positive false alarm rate. The device should be able to handle carry-on as well as checked baggage and should provide indications that are independent of the geometric configuration of the material. The mass density of an explosive compound is relatively high. Also, explosives have high nitrogen and oxygen densities. Most detection techniques exploit the nitrogen-rich nature of explosives. Although few materials have such a high nitrogen density, some plastics, clothing materials and narcotics have also high nitrogen content. In order to distinguish such innocuous materials from explosives, one needs to detect the presence of other elements, particularly oxygen. The measurement of high oxygen density in the inspected object, together with a high nitrogen density, provides a strong indication that the object contains an explosive material. This is the minimum requirement for unambiguous determination of the presence of explosives. An additional measurement will decrease the degree of ambiguity and increase the reliability of the system. A number of radiation based techniques have been developed, or are being considered for the detection of explosives. This paper reviews some of these techniques, based on the type and mode of interaction of the radiation employed

  11. Detonation Propagation Characteristics of Superposition Explosive Materials

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

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

  12. Analysis of TROI-13 Steam Explosion Experiment

    Directory of Open Access Journals (Sweden)

    Mitja Uršič

    2008-01-01

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

  13. 27 CFR 555.181 - Reporting of plastic explosives.

    Science.gov (United States)

    2010-04-01

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

  14. 27 CFR 555.23 - List of explosive materials.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false List of explosive..., FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Administrative and Miscellaneous Provisions § 555.23 List of explosive materials. The Director shall compile a list of...

  15. 27 CFR 555.28 - Stolen explosive materials.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Stolen explosive materials..., AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Administrative and Miscellaneous Provisions § 555.28 Stolen explosive materials. No person shall receive, conceal, transport,...

  16. 30 CFR 75.1310 - Explosives and blasting equipment.

    Science.gov (United States)

    2010-07-01

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

  17. Active sampling technique to enhance chemical signature of buried explosives

    Science.gov (United States)

    Lovell, John S.; French, Patrick D.

    2004-09-01

    Deminers and dismounted countermine engineers commonly use metal detectors, ground penetrating radar and probes to locate mines. Many modern landmines have a very low metal content, which severely limits the effectiveness of metal detectors. Canines have also been used for landmine detection for decades. Experiments have shown that canines smell the explosives which are known to leak from most types of landmines. The fact that dogs can detect landmines indicates that vapor sensing is a viable approach to landmine detection. Several groups are currently developing systems to detect landmines by "sniffing" for the ultra-trace explosive vapors above the soil. The amount of material that is available to passive vapor sensing systems is limited to no more than the vapor in equilibrium with the explosive related chemicals (ERCs) distributed in the surface soils over and near the landmine. The low equilibrium vapor pressure of TNT in the soil/atmosphere boundary layer and the limited volume of the boundary layer air imply that passive chemical vapor sensing systems require sensitivities in the picogram range, or lower. ADA is working to overcome many of the limitations of passive sampling methods, by the use of an active sampling method that employs a high-powered (1,200+ joules) strobe lamp to create a highly amplified plume of vapor and/or ERC-bearing fine particulates. Initial investigations have demonstrated that this approach can amplify the detectability of TNT by two or three orders of magnitude. This new active sampling technique could be used with any suitable explosive sensor.

  18. Subsurface Explosions in Granular Media

    Science.gov (United States)

    Lai, Shuyue; Houim, Ryan; Oran, Elaine

    2015-11-01

    Numerical simulations of coupled gas-granular flows are used to study properties of shock formation and propagation in media, such as sand or regolith on the moon, asteroids, or comets. The simulations were performed with a multidimensional fully compressible model, GRAF, which solves two sets of coupled Navier-Stokes equations, one for the gas and one for the granular medium. The specific case discussed here is for a subsurface explosion in a granular medium initiated by an equivalent of 200g of TNT in depths ranging from 0.1m to 3m. The background conditions of 100K, 10 Pa and loose initial particle volume fraction of 25% are consistent with an event on a comet. The initial blast creates a cavity as a granular shock expands outwards. Since the gas-phase shock propagates faster than the granular shock in loose, granular material, some gas and particles are ejected before the granular shock arrives. When the granular shock reaches the surface, a cap-like structure forms. This cap breaks and may fall back on the surface and in this process, relatively dense particle clusters form. At lower temperatures, the explosion timescales are increased and entrained particles are more densely packed.

  19. Explosive double salts and preparation

    Science.gov (United States)

    Cady, Howard H.; Lee, Kien-yin

    1984-01-01

    Applicants have discovered a new composition of matter which is an explosive addition compound of ammonium nitrate (AN) and diethylenetriamine trinitrate (DETN) in a 50:50 molar ratio. The compound is stable over extended periods of time only at temperatures higher than 46.degree. C., decomposing to a fine-grained eutectic mixture (which is also believed to be new) of AN and DETN at temperatures lower than 46.degree. C. The compound of the invention has an x-ray density of 1.61 g/cm.sup.3, explodes to form essentially only gaseous products, has higher detonation properties (i.e., detonation velocity and pressure) than those of any mechanical mixture having the same density and composition as the compound of the invention, is a quite insensitive explosive material, can be cast at temperatures attainable by high pressure steam, and is prepared from inexpensive ingredients. Methods of preparing the compound of the invention and the fine-grained eutectic composition of the invention are given.

  20. Chernobyl: Anatomy of the explosion

    International Nuclear Information System (INIS)

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

  1. Low Frequency Electromagnetic Pulse and Explosions

    Energy Technology Data Exchange (ETDEWEB)

    Sweeney, J J

    2011-02-01

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

  2. Close-in airblast from underground explosions

    International Nuclear Information System (INIS)

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

  3. A search for gamma-ray bursts from the explosive evaporation of black holes

    International Nuclear Information System (INIS)

    Separated atmospheric Cerenkov detectors have been used to search for bursts of γ-rays, not associated with single air showers, which have been predicted theoretically from the explosion of small black holes. Characteristic detectable energies are in the region 200 - 1000 MeV but higher energy photons would also be detected. Detection sensitivities are in the region 10-13- 10-11 joules/metre2 for bursts of duration less than 1 microsecond. In a preliminary analysis an upper limit for primordial black hole explosions in the galaxy is set at 0.04 events/pc3-year

  4. Data of the 22nd nuclear explosion test of the People's Republic of China

    International Nuclear Information System (INIS)

    US. Energy Research and Development Administration (US ERDA) announced for the 22 nd nuclear explosion test of the People's Republic of China. The radioactivity surveillance was carried out for the period from September 19, to September 28, 1977. From the results of this surveillance, the effects of this nuclear explosion test were detected in the radioactivity measurement of rainwater, dry fallout, air-borne dusts in upper atmosphere, and raw milk samples. Survey on iodine-131 concentrations in raw milk was continued until October 11, 1977. The results of radioactivity surveillance were described in the following articles. (author)

  5. Summary of European directives for explosion safety

    NARCIS (Netherlands)

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

    2008-01-01

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

  6. Glass produced by underground nuclear explosions

    International Nuclear Information System (INIS)

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

  7. Fire and explosion hazards of oil shale

    Energy Technology Data Exchange (ETDEWEB)

    1989-01-01

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

  8. Environmental control for nuclear explosives

    International Nuclear Information System (INIS)

    Peaceful applications introduce some new environmental considerations into the design of nuclear explosives. Much of the experience gained in weapon work can be applied, but the requirement of survival in a very deep hole is not found in any military system. We will briefly mention the overall environment and make a few comparisons with some general characteristics of the weapon environment. The major portion of this paper is devoted to the special problems of pressure and temperature found in the emplacement environment. Potential users should know where we stand with regard to survival in hostile environments in terms of feasibility and possible effects on field operations. In all applications there are several things competing for the available diameter. Given that explosives can be made to work over a range of diameters and that necessary environmental control is feasible, all further discussions can be related to the cost of providing a hole big enough to accomplish the task. The items competing for diameter are: 1) bare nuclear assembly 2) insulation and cooling system if needed 3) pressure canister 4) shielding material 5) emplacement clearance All of these must be considered with the cost of the hole in optimizing an overall design. Conditions in a particular location will affect the shielding requirements and the emplacement clearance. The nuclear assembly can vary in size, but the long development time requires that decisions be made quite early, perhaps in ignorance of the economic details of a particular application. The pressure canister is a relatively straightforward design problem that can be resolved by giving appropriate consideration to all of the design requirements. In particular for 20,000 psi pressure in the emplacement hole, a canister of heat-treated alloy steel having a yield strength of 200,000 psi and a wall thickness which is about .07 times the outside diameter is adequate and straight- forward to fabricate. The insulation and cooling

  9. Explosives remain preferred methods for platform abandonment

    International Nuclear Information System (INIS)

    Economics and safety concerns indicate that methods involving explosives remain the most practical and cost-effective means for abandoning oil and gas structures in the Gulf of Mexico. A decade has passed since 51 dead sea turtles, many endangered Kemp's Ridleys, washed ashore on the Texas coast shortly after explosives helped remove several offshore platforms. Although no relationship between the explosions and the dead turtles was ever established, in response to widespread public concern, the US Minerals Management Service (MMS) and National Marine Fisheries Service (NMFS) implemented regulations limiting the size and timing of explosive charges. Also, more importantly, they required that operators pay for observers to survey waters surrounding platforms scheduled for removal for 48 hr before any detonations. If observers spot sea turtles or marine mammals within the danger zone, the platform abandonment is delayed until the turtles leave or are removed. However, concern about the effects of explosives on marine life remains

  10. Hydrodynamics of Explosion Experiments and Models

    CERN Document Server

    Kedrinskii, Valery K

    2005-01-01

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

  11. Scaled experiments of explosions in cavities

    Science.gov (United States)

    Grun, J.; Cranch, G. A.; Lunsford, R.; Compton, S.; Walton, O. R.; Weaver, J.; Dunlop, W.; Fournier, K. B.

    2016-05-01

    Consequences of an explosion inside an air-filled cavity under the earth's surface are partly duplicated in a laboratory experiment on spatial scales 1000 smaller. The experiment measures shock pressures coupled into a block of material by an explosion inside a gas-filled cavity therein. The explosion is generated by suddenly heating a thin foil that is located near the cavity center with a short laser pulse, which turns the foil into expanding plasma, most of whose energy drives a blast wave in the cavity gas. Variables in the experiment are the cavity radius and explosion energy. Measurements and GEODYN code simulations show that shock pressures measured in the block exhibit a weak dependence on scaled cavity radius up to ˜25 m/kt1/3, above which they decrease rapidly. Possible mechanisms giving rise to this behavior are described. The applicability of this work to validating codes used to simulate full-scale cavity explosions is discussed.

  12. Underwater detection of a TNT explosive

    International Nuclear Information System (INIS)

    Tagged neutron inspection system was used for the detection of explosive in water. Neutrons were produced in d+t nuclear reaction with API-120 sealed tube neutron generator. Five kilograms of the TNT explosive were measured in a pool filled with water. Measurements were done in target in, target out configuration. In addition, a sandwich made of 6 mm thick iron plates with explosive in between was placed between two layers of sea sediments and measured underwater. Sediments were collected in the Adriatic Sea. Measurements were repeated with TNT explosive replaced by rocks of similar size and shape. Neutron tube was rotated in order to find the position and dimension of explosive (rocks) in the sandwich. It was found that TNT can be detected in the water. Moreover, TNT and, sea rocks have had distinguished ratio of carbon and oxygen while measured between 6 mm thick iron plates and placed between layers of sediments. (authors)

  13. Exoplanet Atmospheres

    CERN Document Server

    Seager, S

    2010-01-01

    At the dawn of the first discovery of exoplanets orbiting sun-like stars in the mid-1990s, few believed that observations of exoplanet atmospheres would ever be possible. After the 2002 Hubble Space Telescope detection of a transiting exoplanet atmosphere, many skeptics discounted it as a one-object, one-method success. Nevertheless, the field is now firmly established, with over two dozen exoplanet atmospheres observed today. Hot Jupiters are the type of exoplanet currently most amenable to study. Highlights include: detection of molecular spectral features; observation of day-night temperature gradients; and constraints on vertical atmospheric structure. Atmospheres of giant planets far from their host stars are also being studied with direct imaging. The ultimate exoplanet goal is to answer the enigmatic and ancient question, "Are we alone?" via detection of atmospheric biosignatures. Two exciting prospects are the immediate focus on transiting super Earths orbiting in the habitable zone of M-dwarfs, and u...

  14. Explosion prediction of oil gas using SVM and Logistic Regression

    OpenAIRE

    Wang, Xiaofei; Zhang, Mingming; Shen, Liyong; Gao, Suixiang

    2012-01-01

    The prevention of dangerous chemical accidents is a primary problem of industrial manufacturing. In the accidents of dangerous chemicals, the oil gas explosion plays an important role. The essential task of the explosion prevention is to estimate the better explosion limit of a given oil gas. In this paper, Support Vector Machines (SVM) and Logistic Regression (LR) are used to predict the explosion of oil gas. LR can get the explicit probability formula of explosion, and the explosive range o...

  15. Ionospheric effects of supernova explosions

    Science.gov (United States)

    Edwards, P. J.

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

  16. Halon explosion protection system development

    International Nuclear Information System (INIS)

    A loss-of-coolant-accident in a water-cooled nuclear reactor could result in the accumulation of hydrogen and oxygen gases in the containment vessel, ignition of which might produce explosion pressures that exceed the containment design. Protection against suh a hazard can be provided by an inerting system which utilizes Halon 1301 (CF3Br). This inerting gas would be stored in the liquified state and injected only if needed. A development study is reported in which the quantity of Halon required for inerting has been measured, and several envisioned problems investigated. A sub-scale system has been fabicated and used to simulate operation of an actual system under post-LOCA conditions. The testing, together with a system analysis, indicates that the 1301 inerting concept is very suitable for containment application

  17. Pluto's atmosphere

    International Nuclear Information System (INIS)

    Airborne CCD photometer observations of Pluto's June 9, 1988 stellar occultation have yielded an occultation lightcurve, probing two regions on the sunrise limb 2000 km apart, which reveals an upper atmosphere overlying an extinction layer with an abrupt upper boundary. The extinction layer may surround the entire planet. Attention is given to a model atmosphere whose occultation lightcurve closely duplicates observations; fits of the model to the immersion and emersion lightcurves exhibit no significant derived atmosphere-structure differences. Assuming a pure methane atmosphere, surface pressures of the order of 3 microbars are consistent with the occultation data. 43 references

  18. Atmospheric electricity

    CERN Document Server

    Chalmers, J Alan

    1957-01-01

    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

  19. Chemical analysis kit for the presence of explosives

    Science.gov (United States)

    Eckels, Joel Del; Nunes; Peter J.; Alcaraz, Armando; Whipple, Richard E.

    2011-05-10

    A tester for testing for explosives associated with a test location comprising a first explosives detecting reagent; a first reagent holder, the first reagent holder containing the first explosives detecting reagent; a second explosives detecting reagent; a second reagent holder, the second reagent holder containing the second explosives detecting reagent; a sample collection unit for exposure to the test location, exposure to the first explosives detecting reagent, and exposure to the second explosives detecting reagent; and a body unit containing a heater for heating the sample collection unit for testing the test location for the explosives.

  20. 27 CFR 555.109 - Identification of explosive materials.

    Science.gov (United States)

    2010-04-01

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

  1. Explosive generator development for the SHIVA program. Progress report, January 1, 1975--June 30, 1975

    International Nuclear Information System (INIS)

    A series of experiments performed by SLA, Division 5233, has culminated in two parallel plate explosive generator tests for the SHIVA program. The experimental generators were one-sided devices, 150 mm wide and 600 mm long with a spacing of 50 mm between the explosively driven and the stationary plates. Significant new features in these generators included (1) high point density initiation over the entire 150 mm x 600 mm surface of the driver charge with an electrically exploded copper mesh, and (2) use of a distended copper plate for the wiped surface at the load end of the generator. The distended copper plate minimized formation of a metallic jet at the interface between the driven and wiped plates. Both explosive generator tests reached current gains of about 8 and energy gains of about 4 despite early termination of generation associated with the arrival of a conductive shock front in the helium atmosphere

  2. Generation and characterization of nano aluminium powder obtained through wire explosion process

    Indian Academy of Sciences (India)

    T K Sindhu; R Sarathi; S R Chakravarthy

    2007-04-01

    In the present study, nano aluminium particles were produced by wire explosion process (WEP) in nitrogen, argon and helium atmospheres. Thus produced nano particles were characterized through certain physico-chemical diagnostic studies using wide angle X-ray diffraction (WAXD) and by energy dispersive analysis by X-rays (EDAX). The size and shape of the powder were analysed by using transmission electron microscopic (TEM) studies. The particle size distribution studies were performed by adopting log-normal probability distribution. The relationship between size of the particle generated in the explosion process and the type of inert gas/pressure was analysed. The mechanisms of nano particle formation, the factors which can aid the process of formation of nano particle in the wire explosion process were analysed. It is realized that energy deposited to the conductor and duration of current flow have major impact on particles produced by this process.

  3. DEVELOPMENT OF THE TEST METHODS OF THE CONVEYOR BELTS USED IN ENVIRONMENTS ENDANGERED BY EXPLOSION HAZARDS

    Directory of Open Access Journals (Sweden)

    Florin Adrian PĂUN

    2012-05-01

    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.

  4. Fast Chromatographic Method for Explosive Profiling

    Directory of Open Access Journals (Sweden)

    Pierre-Hugues Stefanuto

    2015-05-01

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

  5. Pixelated diffraction signatures for explosive detection

    Science.gov (United States)

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

    2012-06-01

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

  6. Explosive Volcanic Eruptions from Linear Vents on Earth, Venus and Mars: Comparisons with Circular Vent Eruptions

    Science.gov (United States)

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

    2010-01-01

    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.

  7. Explosive Detection and Identification by PGNAA

    Energy Technology Data Exchange (ETDEWEB)

    E.H. Seabury; A.J. Caffrey

    2004-11-01

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

  8. Explosive Detection and Identification by PGNAA

    International Nuclear Information System (INIS)

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

  9. Terahertz spectroscopy of explosives and drugs

    Directory of Open Access Journals (Sweden)

    A. Giles Davies

    2008-03-01

    Full Text Available Terahertz frequency radiation possesses a unique combination of desirable properties for noninvasive imaging and spectroscopy of materials. This includes the ability to obtain chemical and structural information about substances concealed within dry packaging, such as paper, plastics, and cardboard. As a result, the application of terahertz frequency spectroscopy for the sensing and identification of materials of security interest, such as explosives and, to a lesser extent, drugs-of-abuse, has caught the attention of a number of researchers and security agencies. We describe terahertz time-domain spectroscopy and examine the terahertz spectra of a wide range of drugs-of-abuse, pure explosives, and plastic explosives.

  10. Water waves generated by underwater explosion

    CERN Document Server

    Mehaute, Bernard Le

    1996-01-01

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

  11. Techniques of industrial radiology in military explosives

    International Nuclear Information System (INIS)

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

  12. Explosives detection: a challenge for physical chemistry.

    Science.gov (United States)

    Steinfeld, J I; Wormhoudt, J

    1998-01-01

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

  13. Forensic analyses of explosion debris from the January 2, 1992 Pd/D2O electrochemistry incident at SRI International

    International Nuclear Information System (INIS)

    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

  14. Dwell-time effect on the synthesis of a nano-structured material in water by using Ni wire explosion

    International Nuclear Information System (INIS)

    Nickel nano-structured materials are synthesized by using a wire explosion in water. Based on an analysis of each step of the wire explosion, we propose insufficient energy deposition before a plasma restrike as the cause for the inclusion of coarse particles in the wire-explosion product. We confirmed that more energy, in excess of 30%, could be deposited by increasing the dwell time, which resulted from a compression of vapor by the surrounding water and from suppression of plasma restrikes. Because of an increased energy loss into the surrounding water, the specific energy increased by two-fold compared to a gas atmosphere. The synthesized nano-structured nickel showed a uniform particle size of 20 nm with a few coarse particles that were mainly metallic nickel with a little oxide and hydroxide phases. The possibility for large-volume production through a continuous explosion of 300 shots was confirmed.

  15. Dwell-time effect on the synthesis of a nano-structured material in water by using Ni wire explosion

    Energy Technology Data Exchange (ETDEWEB)

    Eom, Gyu Sub; Kwon, Hyeok Jung; Cho, Yong Sub [Korea Atomic Energy Research Institute, Gyeongju (Korea, Republic of); Paek, Kwang Hyun; Joo, Won Tae [Plasnix Co., Ltd., Inchon (Korea, Republic of)

    2014-10-15

    Nickel nano-structured materials are synthesized by using a wire explosion in water. Based on an analysis of each step of the wire explosion, we propose insufficient energy deposition before a plasma restrike as the cause for the inclusion of coarse particles in the wire-explosion product. We confirmed that more energy, in excess of 30%, could be deposited by increasing the dwell time, which resulted from a compression of vapor by the surrounding water and from suppression of plasma restrikes. Because of an increased energy loss into the surrounding water, the specific energy increased by two-fold compared to a gas atmosphere. The synthesized nano-structured nickel showed a uniform particle size of 20 nm with a few coarse particles that were mainly metallic nickel with a little oxide and hydroxide phases. The possibility for large-volume production through a continuous explosion of 300 shots was confirmed.

  16. Explosives vapour identification in ion mobility spectrometry using a tunable laser ionization source: a comparison with conventional 63Ni ionization

    International Nuclear Information System (INIS)

    Laser multiphoton ionization (MPI) is used to produce ions from explosive vapours at atmospheric pressure in air for analysis by ion mobility spectrometry (IMS). In the positive ion mode of detection, NO+ ions, generated directly by multiphoton dissociation/ionization of the explosive compounds, show strong variation with laser wavelength. This provides a means of identifying the presence of nitro-containing compounds. Moreover, electrons formed in the MPI of gaseous components in the air carrier stream, primarily O2, are transferred via neutral molecular oxygen (O2) to trace explosive vapour, forming negative ions which give rise to characteristic and identifiable ion mobility spectra. Further, negative ion mobility spectra of several explosive vapours are presented using conventional 63Ni ionization and are compared qualitatively with the laser ionization approach. (author)

  17. Ionospheric response to the entry and explosion of the South Ural superbolide

    Science.gov (United States)

    Ruzhin, Yu. Ya.; Kuznetsov, V. D.; Smirnov, V. M.

    2014-09-01

    The South Ural meteoroid (February 15, 2013; near the city of Chelyabinsk) is undoubtedly the best documented meteoroid in history. Its passage through the atmosphere has been recorded on videos and photographs, visually by observers, with ground-based infrasound microphones and seismographs, and by satellites in orbit. In this work, the results are presented of an analysis of the transionospheric GPS sounding data collected in the vicinity of the South Ural meteoroid site, which show a weak ionospheric effect. The ionospheric disturbances are found to be asymmetric about the explosion epicenter. The received signals are compared, both in shape and amplitude, with the reported ionospheric effects of ground level explosions with radio diagnostics. It is shown that the confident registration of ionospheric effects as acoustic gravity waves (AGWs) by means of vertical sounding and GPS technologies for ground explosions in the range of 0.26-0.6 kt casts doubt on the existing TNT equivalent estimates (up to 500 kt) for the Chelyabinsk event. The absence of effects in the magnetic field and in the ionosphere far zone at distances of 1500-2000 km from the superbolide explosion epicenter also raises a question about the possibility of an overestimated TNT equivalent. An alternative explanation is to consider the superposition of a cylindrical ballistic wave (due to the hypersonic motion of the meteoroid) with spherical shock waves caused by the multiple time points of fragmentation (multiple explosions) of the superbolide as a resulting source of the AGW impact on ionospheric layers.

  18. A thermal explosion process to fabricate an intermetallic matrix composite coating on a steel

    International Nuclear Information System (INIS)

    The thermodynamic analysis and thermal explosion tests in an argon atmosphere for the Ti-C-3Ni-Al system were carried out. An intermetallic matrix composite coating on a steel was fabricated by the thermal explosion reactions of the Ti-C-3Ni-Al system in melt. The thermal explosion products and coatings were examined using XRD and SEM. TiC and Ni3Al were the final products of the thermal explosion reactions of the Ti-C-3Ni-Al system in argon or melt. The addition of 2 wt.% Mg was helpful to reduce the incubation time at the ignition temperature and the size of TiC. But the excess amount of Mg led to the formation of inclusions. During the thermal explosion reactions of the Ti-C-3Ni-Al system in melt, Ni-Al as an ignition agent and Mg as an active agent ensured the ignition and completion of the reactions. The formation of the intermetallic matrix composite coatings on the steel was closely related with the weight ratio of TiC. The microstructure and the interface in the coatings turned to be dense with increasing the weight ratio of TiC. The sound composite coatings firmly bonded with the steel were achieved as the weight ratio of TiC reached 35 wt.% or above.

  19. Explosion craters associated with shallow submarine gas venting off Panarea island, Italy

    Science.gov (United States)

    Monecke, Thomas; Petersen, Sven; Hannington, Mark D.; Anzidei, Marco; Esposito, Alessandra; Giordano, Guido; Garbe-Schönberg, Dieter; Augustin, Nico; Melchert, Bernd; Hocking, Mike

    2012-11-01

    Explosions of hot water, steam, and gas are common periodic events of subaerial geothermal systems. These highly destructive events may cause loss of life and substantial damage to infrastructure, especially in densely populated areas and where geothermal systems are actively exploited for energy. We report on the occurrence of a large number of explosion craters associated with the offshore venting of gas and thermal waters at the volcanic island of Panarea, Italy, demonstrating that violent explosions similar to those observed on land also are common in the shallow submarine environment. With diameters ranging from 5 to over 100 m, the observed circular seafloor depressions record a history of major gas explosions caused by frequent perturbation of the submarine geothermal system over the past 10,000 years. Estimates of the total gas flux indicate that the Panarea geothermal system released over 70 Mt of CO2 over this period of time, suggesting that CO2 venting at submerged arc volcanoes contributes significantly to the global atmospheric budget of this greenhouse gas. The findings at Panarea highlight that shallow submarine gas explosions represent a previously unrecognized volcanic hazard around populated volcanic islands that needs to be taken into account in the development of risk management strategies.

  20. Mechanical constraints on the triggering of vulcanian explosions at Santiaguito volcano, Guatemala

    Science.gov (United States)

    Hornby, Adrian; Lavallée, Yan; Collinson, Amy; Neuberg, Jurgen; De Angelis, Silvio; Kendrick, Jackie; Lamur, Anthony

    2016-04-01

    Gas- and ash explosions at Santiaguito volcano occur at regular 20-200 minute intervals, exiting through arcuate fractures in the summit dome of the Caliente vent. Infrasound, ground deformation and seismic monitoring collected during a long term monitoring survey conducted by the University of Liverpool have constrained a stable, repeatable source for these explosions. The explosions maintain similar magnitudes and (low) erupted mass throughout examined period. Ground deformation reveals stable ~25 minute inflation-deflation cycles, which culminate in either explosions or passive outgassing. Inversion of infrasound sources has revealed that faster inflation rates during the final minutes before peak inflation lead to explosions. These explosions fragment a consistently small-volume pressurized, gas-rich domain within magma located below a denser, lower permeability magma plug. Rapid decompression of this gas-rich domain occurs through fracturing and faulting, creating a highly permeable connection with atmospheric pressures near to the dome surface. We surmise that the dominant fracture mode at these shallow depths is tensile due to the volumetric strain exerted by a pressurising source below the magma plug, however a component of shear is also detected during explosive events. Fractures may either propagate downwards from the dome surface (due to greater magma stiffness and lower confining pressure) or upwards from the gas-rich domain (due to higher strain rates at the deformation source in the case of viscous deformation). In order to constrain the origin and evolution of these fractures we have conducted Brazilian tensile stress tests on lavas from the Caliente vent at strain rates from 10-3-10-5, porosities 3-30% and temperatures 20-800 °C. Across the expected conduit temperature range (750-800 °C) the dome material becomes highly sensitive to strain rate, showing a range of response from elastic failure to viscous flow. The total strain accommodated prior

  1. Explosiveness of mist/steam/air or mist/gas/air mixtures

    International Nuclear Information System (INIS)

    The accidental release of a pressurized gas or liquid not only may lead to an explosive gas- or vapour-cloud, but even more may form a mist/gas/air-cloud (hybrid mixture cloud) and so risk analysis is faced with the question, if such hybrid mixtures may give rise to higher flame speeds and consequently higher explosion pressurizes and more severe damages than gas- or vapour-clouds of comparable turbulence and fuel concentration. This question is dealt with by measuring the flame velocities of test mixtures (octanol mist, propan gas and air) in a 1,7 m3 vessel; the turbulence, the concentration of gaseous and liquid fuel and the mean drop size of the liquid phase are investigated as influencing parameters. Concerning the generation of the mist component the results indicate, that explosive mist/air-mixtures of moderate (e.g. atmospheric) turbulence are instable with respect to droplet-coagulation and so - due to the rapid sedimentation of large coagulated droplets - the spreading of explosive mist-air-mixtures under atmospheric turbulence will be rather limited. (orig./RW)

  2. A COMPUTER MODEL OF THE CONSEQUENCES OF AIR-FUEL MIXTURE EMERGENCY EXPLOSIONS

    Directory of Open Access Journals (Sweden)

    Orishenko I. V.

    2015-02-01

    Full Text Available In this article the basic principles of air-fuel mixture explosions and striking factors, such as air-striking wave, gas streams, splinters, flame heat, light radiation and sharp sounds are observed. The calculation technique of the emergency emission consequences which is for a quantitative estimation of air-striking wave parameters at air-fuel mixture explosions forming in the atmosphere at industrial failures is given. The basic structural elements of calculation algorithm are listed. It is supposed partial depressurization or full destruction of the equipment containing combustible substance in a gaseous or liquid phase, the emission of this substance in the atmosphere, the air-fuel mixture cloud formation, the air-fuel mixture initiation (ignition and the explosive transformation (deflagration or detonation in the air-fuel mixture cloud. The technique allows making the approached estimation of air-striking wave various parameters and defining the probable degrees of men defeat and building damage at failures with air-fuel mixture cloud explosions. The given technique is developed in C# language in the integrated environment of software Microsoft VisualStudio 2010 working out. The program fragment in which the calculation of dimensionless Px pressure and dimensionless Ix impulse is given

  3. GPS Detection of Ionospheric Waves following the 2003 Explosion of the Soufriere Hills Volcano, Montserrat

    Science.gov (United States)

    Mattioli, G. S.; Dautermann, T.; Calais, E.

    2006-12-01

    Sources such as volcanic explosions or shallow earthquakes are known to produce pressure waves that propagate at infrasonic speeds in the atmosphere. Because of the coupling between neutral particles and electrons at ionospheric altitudes, these acoustic waves induce variations of the ionospheric electron density that are detectable by GPS measurements. We used near- and far-field GPS data around Montserrat (Lesser Antilles) and detected ionospheric perturbations following explosion of the Soufriere Hills Volcano on July 13th , 2003. The wave is detected north of the island, in an area of maximum alignment between a spherical shockwave and the Earth's magnetic field, and travels at an apparent velocity consistent with sound speed. Frequency content ranges between 0.6 mHz and 5 mHz, consistent with previous observations after volcanic explosions. Some of these frequencies are also recorded by borehole strainmeters and seismic stations installed on Montserrat. Using normal mode theory, we show that the coupling of atmospheric waves (triggered by the explosion) back to solid Earth explains the signal observed in the strainmeter data.

  4. Modern microcenter heat explosion model

    International Nuclear Information System (INIS)

    Modernization and investigation of the microcenter heat explosion model of the energetic materials initiated by the pulse radiation was made in this paper. Absorptivity of aluminium nanoparticles in PETN-matrix was calculated and was taken into account. Dependences of the absorptivity on the particles' sizes and wave length of irradiation was also taken into account. It was shown that the particle's radius, which corresponds to the absorption maximum, and the peak value both depend on the irradiation wave length. For the first harmonic of the ND:YAG laser the absorption maximum corresponds to the nanoparticle's radius 100 nm, for the second harmonic to the radius it is 44 nm. The peak value increases from 0.2942 to 0.7064. Dependences of the critical initiation energy densities on the metal inclusions' radii were calculated for the energetic materials. It was concluded that the RDX – aluminium composite is the perspective material to use in optic detonator especially for the second harmonic of the ND:YAG laser

  5. Explosive and pyrotechnic aging demonstration

    Science.gov (United States)

    Rouch, L. L., Jr.; Maycock, J. N.

    1976-01-01

    The survivability was experimentally verified of fine selected explosive and pyrotechnic propellant materials when subjected to sterilization, and prolonged exposure to space environments. This verification included thermal characterization, sterilization heat cycling, sublimation measurements, isothermal decomposition measurements, and accelerated aging at a preselected elevated temperature. Temperatures chosen for sublimation and isothermal decomposition measurements were those in which the decomposition processess occurring would be the same as those taking place in real-time aging. The elevated temperature selected (84 C) for accelerated aging was based upon the parameters calculated from the kinetic data obtained in the isothermal measurement tests and was such that one month of accelerated aging in the laboratory approximated one year of real-time aging at 66 C. Results indicate that HNS-IIA, pure PbN6, KDNBF, and Zr/KC10 are capable of withstanding sterilization. The accelerated aging tests indicated that unsterilized HNS-IIA and Zr/KC104 can withstand the 10 year, elevated temperature exposure, pure PbN6 and KDNBF exhibit small weight losses (less than 2 percent) and B/KC104 exhibits significant changes in its thermal characteristics. Accelerated aging tests after sterilization indicated that only HNS-IIA exhibited high stability.

  6. Supernova neutrinos and explosive nucleosynthesis

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-05-09

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

  7. Supernova explosions in the Universe.

    Science.gov (United States)

    Burrows, A

    2000-02-17

    During the lifetime of our Milky Way galaxy, there have been something like 100 million supernova explosions, which have enriched the Galaxy with the oxygen we breathe, the iron in our cars, the calcium in our bones and the silicon in the rocks beneath our feet. These exploding stars also influence the birth of new stars and are the source of the energetic cosmic rays that irradiate us on the Earth. The prodigious amount of energy (approximately 10(51), or approximately 2.5 x 10(28) megatonnes of TNT equivalent) and momentum associated with each supernova may even have helped to shape galaxies as they formed in the early Universe. Supernovae are now being used to measure the geometry of the Universe, and have recently been implicated in the decades-old mystery of the origin of the gamma-ray bursts. Together with major conceptual advances in our theoretical understanding of supernovae, these developments have made supernovae the centre of attention in astrophysics. PMID:10693794

  8. Glossary on peaceful nuclear explosions terms

    International Nuclear Information System (INIS)

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

  9. Traumatic corneal endothelial rings from homemade explosives.

    Science.gov (United States)

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

    2013-08-01

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

  10. Explosives Detection and Identification by PGNAA

    Energy Technology Data Exchange (ETDEWEB)

    E. H. Seabury; A. J. Caffrey

    2006-04-01

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

  11. Explosives Detection and Identification by PGNAA

    International Nuclear Information System (INIS)

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

  12. Optical chemosensors and reagents to detect explosives

    OpenAIRE

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

    2012-01-01

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

  13. Numerical Simulation of Underwater Explosion Loads

    Institute of Scientific and Technical Information of China (English)

    XIN Chunliang; XU Gengguang; LIU Kezhong

    2008-01-01

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

  14. Isolator fragmentation and explosive initiation tests

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-09-30

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

  15. EXPLOSIVE MEANS TO SEPARATE CASING MEMBERS

    Science.gov (United States)

    Botsford, N.B.

    1962-05-01

    This patent relates to a case having separable sections with intermediate interfitting tongue and groove portions. An explosive or gas generator between the tongue and groove forces them apart, when actuated, and serves to separate the case sections. (AEC)

  16. Rabbit lung injury induced by explosive decompression

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

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

  17. Unreacted Hugoniots for porous and liquid explosives

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-08-01

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

  18. Magnetorotational Explosive Instability in Keplerian Disks

    CERN Document Server

    Shtemler, Yuri; Mond, Michael

    2015-01-01

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

  19. Corona-discharge-initiated mine explosions

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-10-01

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

  20. Articulating Atmospheres

    DEFF Research Database (Denmark)

    Kinch, Sofie

    2011-01-01

    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......” 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....

  1. Exoplanetary Atmospheres

    CERN Document Server

    Madhusudhan, Nikku; Fortney, Jonathan; Barman, Travis

    2014-01-01

    The study of exoplanetary atmospheres is one of the most exciting and dynamic frontiers in astronomy. Over the past two decades ongoing surveys have revealed an astonishing diversity in the planetary masses, radii, temperatures, orbital parameters, and host stellar properties of exoplanetary systems. We are now moving into an era where we can begin to address fundamental questions concerning the diversity of exoplanetary compositions, atmospheric and interior processes, and formation histories, just as have been pursued for solar system planets over the past century. Exoplanetary atmospheres provide a direct means to address these questions via their observable spectral signatures. In the last decade, and particularly in the last five years, tremendous progress has been made in detecting atmospheric signatures of exoplanets through photometric and spectroscopic methods using a variety of space-borne and/or ground-based observational facilities. These observations are beginning to provide important constraints...

  2. 30 CFR 56.6302 - Separation of explosive material.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Separation of explosive material. 56.6302... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Use § 56.6302 Separation of explosive material. Explosives and blasting agents shall be kept separated...

  3. 30 CFR 56.6100 - Separation of stored explosive material.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Separation of stored explosive material. 56... Explosives Storage § 56.6100 Separation of stored explosive material. (a) Detonators shall not be stored in the same magazine with other explosive material. (b) When stored in the same magazine, blasting...

  4. 30 CFR 56.6130 - Explosive material storage facilities.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Explosive material storage facilities. 56.6130... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Storage § 56.6130 Explosive material storage facilities. (a) Detonators and explosives shall be stored...

  5. 30 CFR 57.6130 - Explosive material storage facilities.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Explosive material storage facilities. 57.6130... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives Storage-Surface Only § 57.6130 Explosive material storage facilities. (a) Detonators and explosives...

  6. 30 CFR 56.6900 - Damaged or deteriorated explosive material.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Damaged or deteriorated explosive material. 56... Explosives General Requirements § 56.6900 Damaged or deteriorated explosive material. Damaged or deteriorated explosive material shall be disposed of in a safe manner in accordance with the instructions of...

  7. 30 CFR 56.6305 - Unused explosive material.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Unused explosive material. 56.6305 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Use § 56.6305 Unused explosive material. Unused explosive material shall be moved to a protected location...

  8. 30 CFR 57.6100 - Separation of stored explosive material.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Separation of stored explosive material. 57... Explosives Storage-Surface and Underground § 57.6100 Separation of stored explosive material. (a) Detonators shall not be stored in the same magazine with other explosive material. (b) When stored in the...

  9. 30 CFR 57.6305 - Unused explosive material.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Unused explosive material. 57.6305 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives Transportation-Surface and Underground § 57.6305 Unused explosive material. Unused explosive material shall...

  10. 30 CFR 57.6102 - Explosive material storage practices.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Explosive material storage practices. 57.6102... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives Storage-Surface and Underground § 57.6102 Explosive material storage practices. (a) Explosive...

  11. 30 CFR 56.6102 - Explosive material storage practices.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Explosive material storage practices. 56.6102... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Storage § 56.6102 Explosive material storage practices. (a) Explosive material shall be— (1) Stored in...

  12. 27 CFR 555.202 - Classes of explosive materials.

    Science.gov (United States)

    2010-04-01

    ... as UN0333, UN0334, or UN0335 by the U.S. Department of Transportation regulations at 49 CFR 172.101... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Classes of explosive..., FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Storage § 555.202...

  13. 30 CFR 57.6903 - Burning explosive material.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Burning explosive material. 57.6903 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives General Requirements-Surface and Underground § 57.6903 Burning explosive material. If explosive...

  14. 30 CFR 75.1314 - Sheathed explosive units.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Sheathed explosive units. 75.1314 Section 75... HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1314 Sheathed explosive units. (a) A separate instantaneous detonator shall be used to fire each sheathed explosive...

  15. 30 CFR 57.6302 - Separation of explosive material.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Separation of explosive material. 57.6302... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives Transportation-Surface and Underground § 57.6302 Separation of explosive material. Explosives and blasting...

  16. 30 CFR 56.6905 - Protection of explosive material.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Protection of explosive material. 56.6905... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives General Requirements § 56.6905 Protection of explosive material. (a) Explosive material shall be...

  17. 30 CFR 56.6903 - Burning explosive material.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Burning explosive material. 56.6903 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives General Requirements § 56.6903 Burning explosive material. If explosive material is suspected of burning at the...

  18. 30 CFR 77.1300 - Explosives and blasting.

    Science.gov (United States)

    2010-07-01

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

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

    Directory of Open Access Journals (Sweden)

    Chun Hua Bai

    2013-07-01

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

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

    Directory of Open Access Journals (Sweden)

    Chun-Hua Bai

    2013-07-01

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

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

    International Nuclear Information System (INIS)

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

  2. [Pulmonary contusion and hemothorax due to explosion].

    Science.gov (United States)

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

    2006-01-01

    Folklore and "uses and customs" in countries such as Mexico, under certain circumstances, have direct influences on risks for traumatic injuries. 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." A pleurostomy tube was required to resolve symptomatic hemothorax. The patient was discharged 5 days after admission. PMID:17257490

  3. The ionospheric effects of industrial explosions

    Science.gov (United States)

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

    1984-04-01

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

  4. Weapons Experiments Division Explosives Operations Overview

    Energy Technology Data Exchange (ETDEWEB)

    Laintz, Kenneth E. [Los Alamos National Laboratory

    2012-06-19

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

  5. Differential thermal analysis microsystem for explosive detection

    DEFF Research Database (Denmark)

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

    2011-01-01

    A micro differential thermal analysis (DTA) system is used for detection of trace explosive particles. The DTA system consists of two silicon micro chips with integrated heaters and temperature sensors. One chip is used for reference and one for the measurement sample. The sensor is constructed 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....

  6. Wave generations from confined explosions in rocks

    OpenAIRE

    C. L. Liu; Ahrens, Thomas J.

    1998-01-01

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

  7. Managing traumatic brain injury secondary to explosions

    Directory of Open Access Journals (Sweden)

    Burgess Paula

    2010-01-01

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

  8. Stabilization of explosive compounds on metallic surfaces

    International Nuclear Information System (INIS)

    Full text: Previous experiments on explosives like RDX, TNT or PETN in gas phase have shown that these molecules decay easily into several fragments upon low-energy electron attachment. These unimolecular decompositions are rather time consuming (several μs) and can be quenched when the molecules are embedded in helium nano droplets. With the use of a variable temperature scanning tunneling microscope, electron induced fragmentation of explosives is investigated for molecules adsorbed on single crystal metal surfaces. (author)

  9. Projectile-generating explosive access tool

    Science.gov (United States)

    Jakaboski, Juan-Carlos; Hughs, Chance G; Todd, Steven N

    2013-06-11

    A method for generating a projectile using an explosive device that can generate a projectile from the opposite side of a wall from the side where the explosive device is detonated. The projectile can be generated without breaching the wall of the structure or container. The device can optionally open an aperture in a solid wall of a structure or a container and form a high-kinetic-energy projectile from the portion of the wall removed to create the aperture.

  10. Scaling the electromagnetically driven explosive shock simulator

    Science.gov (United States)

    Persh, Robert I.

    1987-01-01

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

  11. Did Gamma Ray Burst Induce Cambrian Explosion?

    OpenAIRE

    Chen, Pisin; Ruffini, Remo

    2014-01-01

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

  12. Staging atmospheres

    DEFF Research Database (Denmark)

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

    2015-01-01

    . Nevertheless, people’s experience of the environment is sought manipulated in a variety of contexts, often without offering a less ‘true’ experience of a situation than if it had not been manipulated by people. In fact, orchestrations of space are often central to sociality, politics and aesthetics. This...... introduction seeks to outline how a number of scholars have addressed the relationship between staged atmospheres and experience, and thus highlight both the philosophical, social and political aspects of atmospheres...

  13. Successive soliton explosions in an ultrafast fiber laser.

    Science.gov (United States)

    Liu, Meng; Luo, Ai-Ping; Yan, Yu-Rong; Hu, Song; Liu, Yi-Chen; Cui, Hu; Luo, Zhi-Chao; Xu, Wen-Cheng

    2016-03-15

    Soliton explosions, as one of the most fascinating nonlinear phenomena in dissipative systems, have been investigated in different branches of physics, including the ultrafast laser community. Herein, we reported on the soliton dynamics of an ultrafast fiber laser from steady state to soliton explosions, and to huge explosions by simply adjusting the pump power level. In particular, the huge soliton explosions show that the exploding behavior could operate in a sustained, but periodic, mode from one explosion to another, which we term as "successive soliton explosions." The experimental results will prove to be fruitful to the various communities interested in soliton explosions. PMID:26977664

  14. Spectroscopic characterization of nitroaromatic landmine signature explosives

    Science.gov (United States)

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

    2004-09-01

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

  15. THE BIGGEST EXPLOSIONS IN THE UNIVERSE

    International Nuclear Information System (INIS)

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

  16. Risk Assessment Study for Storage Explosive

    Directory of Open Access Journals (Sweden)

    S. S. Azhar

    2006-01-01

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

  17. Explosive compaction of CuCr alloys

    Institute of Scientific and Technical Information of China (English)

    李金平; 罗守靖; 龚朝晖; 牛玮; 纪松

    2002-01-01

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

  18. Statistical estimation of loads from gas explosions

    Energy Technology Data Exchange (ETDEWEB)

    Hoeiset, Stian

    1998-12-31

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

  19. Screening sealed bottles for liquid explosives

    Science.gov (United States)

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

    1997-01-01

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

  20. Smart semiconductor bridge (SCB) igniter for explosives

    Science.gov (United States)

    Bickes, R. W., Jr.

    We have developed a silicon semiconductor bridge (SCB) igniter which, when driven with a low-energy current pulse, produces a plasma discharge that ignites explosive materials pressed against the bridge. Our experiments have demonstrated that SCB explosive devices function in a few tens of microseconds at one-tenth the input energy of hot-wire devices. Despite the low input energies for ignition, tests have revealed SCB devices to be explosively safe, passing electrostatic discharge (ESD) requirements and no-fire current levels. In fact, SCB devices have better no-fire characteristics than hot-wire devices, because of the intimate bridge contact with the underlying thermally conductive substrate. We have tested several different prototype explosive devices including pyrotechnic actuators, secondary explosive deflagration-to-detonation detonators and a primary explosive detonator. In addition, we have tested SCB actuators with breadboarded smart firing sets that will fire the SCB actuators only after transmission of a digital code, after a preset delay, or in a preprogrammed sequence. We have also tested an optical system that requires only a single fiber optic cable connecting the SCB device to a low power laser that both energizes the firing set and transmits a coded firing signal.

  1. Explosive vapor detection payload for small robots

    Science.gov (United States)

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

    2013-05-01

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

  2. Experimental Study on Unconfined Vapor Cloud Explosion

    Institute of Scientific and Technical Information of China (English)

    毕明树; ABULITI; Abudula

    2003-01-01

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

  3. Detection and analysis of explosives by nuclear techniques

    International Nuclear Information System (INIS)

    In today's global environment of international terrorism, there is a well recognised need for sensitive and specific techniques for detection and analysis of explosives. Sensitivity is needed for detection of small amounts of explosives hidden or mixed with post explosion residues. Specificity is needed in order to avoid response, to non-explosive substances. The conventional techniques for detection of explosives based on vapour detection either by sniffer dogs or by some instrumental vapour detectors have limitations because of their inability to detect plastic bonded explosives which has vapour pressure significantly lower than pure explosives. The paper reviews the various nuclear techniques such as thermal, fast and pulsed fast neutron activation analysis which are used for detection of pure explosives, mixtures of explosives, and also aluminized and plastic bonded explosives. (author)

  4. Evaluation of sulfur dioxide emissions from explosive volcanism: the 1982-1983 eruptions of Galunggung, Java, Indonesia

    Science.gov (United States)

    Bluth, G.J.S.; Casadevall, T.J.; Schnetzler, C.C.; Doiron, S.D.; Walter, Louis S.; Krueger, A.J.; Badruddin, M.

    1994-01-01

    Galunggung volcano, Java, awoke from a 63-year quiescence in April 1982, and erupted sporadically through January 1983. During its most violent period from April to October, the Cikasasah Volcano Observatory reported 32 large and 56 moderate to small eruptions. From April 5 through September 19 the Total Ozone Mapping Spectrometer (TOMS), carried on NASA's Nimbus-7 satellite, detected and measured 24 different sulfur dioxide clouds; an estimated 1730 kilotons (kt) of SO2 were outgassed by these explosive eruptions. The trajectories, and rapid dispersion rates, of the SO2 clouds were consistent with injection altitudes below the tropopause. An additional 300 kt of SO2 were estimated to have come from 64 smaller explosive eruptions, based on the detection limit of the TOMS instrument. For the first time, an extended period of volcanic activity was monitored by remote sensing techniques which enabled observations of both the entire SO2 clouds produced by large explosive eruptions (using TOMS), and the relatively lower levels of SO2 emissions during non-explosive outgassing (using the Correlation Spectrometer, or COSPEC). Based on COSPEC measurements from August 1982 to January 1983, and on the relationship between explosive and non-explosive degassing, approximately 400 kt of SO2 were emitted during non-explosive activity. The total sulfur dioxide outgassed from Galunggung volcano from April 1982 to January 1983 is calculated to be 2500 kt (?? 30%) from both explosive and non-explosive activity. While Galunggung added large quantities of sulfur dioxide to the atmosphere, its sporadic emissions occurred in relatively small events distributed over several months, and reached relatively low altitudes, and are unlikely to have significantly affected aerosol loading of the stratosphere in 1982 by volcanic activity. ?? 1994.

  5. Observations of ionospheric disturbances following a 5-kt chemical explosion. I - Persistent oscillation in the lower thermosphere after shock passage

    Science.gov (United States)

    Jacobson, Abram R.; Carlos, Robert C.; Blanc, Elizabeth

    1988-10-01

    A 6-min-period oscillation persisting for an hour has been observed in the ionospheric E region following a 5-kt chemical explosion on the ground 250 km south of the measurement site. The oscillations' phase velocity in the upper atmosphere is 0.15 km/s at an azimuth 60 W.

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

    OpenAIRE

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

    2006-01-01

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

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

    Science.gov (United States)

    Cotte-Rodríguez, Ismael; Takáts, Zoltán; Talaty, Nari; Chen, Huanwen; Cooks, R Graham

    2005-11-01

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

  8. Numerical modeling of explosions for nuclear monitoring

    Science.gov (United States)

    Stevens, J. L.

    2014-12-01

    Monitoring the Earth for underground nuclear explosions requires a detailed understanding of the explosion source. In this context, "source" refers to the source of seismic waves, and it is generated by the complex nonlinear near-source motion that accompanies the nuclear explosion. In particular, nuclear monitoring requires understanding the transition from the hydrodynamic to elastic regimes, and propagation of waveforms from the source to stations at distances of hundreds to thousands of kilometers. In the transition region, shear strength is critically important, as are changes in shear strength as the shock wave propagates. Numerical modeling using 1D spherically symmetric, 2D axisymmetric and full 3D calculations provides important insights into the seismic source and the waveforms it generates. Important considerations for numerical modeling include emplacement conditions (tamped or in a cavity), source type (chemical or nuclear), material models for strength and strength reduction, and geologic conditions including topography and tectonic stresses in the source region. In addition to calculating the near source ground motion, we propagate the near source solution to regional and teleseismic distances where the observations of seismic signals from nuclear explosions are made. The objectives of nuclear monitoring are detection of seismic events (earthquakes, quarry blasts and other sources in addition to nuclear explosions), accurate location of these events, discrimination of nuclear explosions from other types of sources, and estimation of nuclear explosion yield. Numerical modeling is particularly important for discrimination and yield estimation. Numerical modeling is used to understand unexpected anomalies that occur, such as the large surface waves generated by the three North Korean nuclear tests, which may have been caused by a difference in tectonic stress state between North Korea and other test sites. Another important issue that can be addressed

  9. Modelling of vapour explosion in stratified geometrie

    International Nuclear Information System (INIS)

    When a hot liquid comes into contact with a colder volatile liquid, one can obtain in some conditions an explosive vaporization, told vapour explosion, whose consequences can be important on neighbouring structures. This explosion needs the intimate mixing and the fine fragmentation between the two liquids. In a stratified vapour explosion, these two liquids are initially superposed and separated by a vapor film. A triggering of the explosion can induce a propagation of this along the film. A study of experimental results and existent models has allowed to retain the following main points: - the explosion propagation is due to a pressure wave propagating through the medium; - the mixing is due to the development of Kelvin-Helmholtz instabilities induced by the shear velocity between the two liquids behind the pressure wave. The presence of the vapour in the volatile liquid explains experimental propagation velocity and the velocity difference between the two fluids at the pressure wave crossing. A first model has been proposed by Brayer in 1994 in order to describe the fragmentation and the mixing of the two fluids. Results of the author do not show explosion propagation. We have therefore built a new mixing-fragmentation model based on the atomization phenomenon that develops itself during the pressure wave crossing. We have also taken into account the transient aspect of the heat transfer between fuel drops and the volatile liquid, and elaborated a model of transient heat transfer. These two models have been introduced in a multi-components, thermal, hydraulic code, MC3D. Results of calculation show a qualitative and quantitative agreement with experimental results and confirm basic options of the model. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-10-01

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

  11. Relationship between the Neoproterozoic snowball Earth and Cambrian explosion

    Science.gov (United States)

    Maruyama, S.; Yoshihara, A.; Isozaki, Y.

    2007-12-01

    Origin of snowball Earth has been debated in terms of greenhouse gas (e.g., Hoffman and Schrag), obliqueness of Earth's rotation axis (Williams, 1975), true polar wander (Evans, 2003), Galactic cosmic ray radiation (Shaviv and Veizer, 2003; Svensmark, 2006), or weakened geomagnetism (Maruyama and Yoshihara, 2003). A major difficulty for the greenhouse gas hypothesis is the on-off switch causing decrease and increase of appropriate amounts of CO2 by plume- and plate tectonics, and also in available amount of CO2 in atmosphere to be consistent with the observations. In contrast, the cosmic ray radiation models due to the star burst peaked at 2.5- 2.1 Ga and 1.4-0.8 Ga can explain on-off switch more easily than the greenhouse gas model. Cosmic ray radiations, however, must be modified by the geomagnetic intensity, fluctuating 150"% to cause the snowball Earth. Time difference between the Neoproterozoic snowball Earth and Cambrian explosion is as large as 250 millions years, and this refuses their direct close-relationship. Role of frequent mass extinctions, i.e., 8 times during 100 m.y. from 585 Ma to 488 Ma, during the Ediacaran and Cambrian, has been proposed (Zhu et al., 2007). This frequency is one order of magnitude higher compared to that in the post-Ordovician time. Yet, the Cambrian explosion cannot be explained by mass extinction which replaced the vacant niches shortly after the mass extinction and never created a new animal with a new body plan. A new model proposed herein is derived from weakened geomagnetism and resultant extensive cosmic radiation to alter gene and genome for a long period over advancement of low magnetic intensity and cosmic radiations (Svensmark, 2006) from 1.2-0.8Ga. As to the new body plans of animals, it took an appreciably long time to prepare all 34 genometypes before the apparent Cambrian explosion. Geochemically extreme conditions and widened shallow marine environment on continental shelf by the return-flow of sweater into

  12. Atmospheric thermodynamics

    CERN Document Server

    Iribarne, J V

    1973-01-01

    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...

  13. Atmospheric Smell

    DEFF Research Database (Denmark)

    Stenslund, Anette

    awareness. Subsequently, visitor interviews revealed how a museum-staged hospital atmosphere of an art installation was directly addressed owing to its smell. Curiously, this observation speaks against prevailing literature portraying smell as the ‘mute sense’, and what is more, the museum display did not...... alter smell curatorially. Rather, smell was gestured through non-olfactory effects and it was put in words metonymically, gesturing a reversibly synaesthetic atmosphere of a hospital. Visitor conversations revealed how smell could be poignantly picked up in situ, yet not until frequenting the museum...

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-02-01

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

  16. Possibility of hydrogen explosion and CO explosion caused by corium concrete interaction

    International Nuclear Information System (INIS)

    New safety standards of NPP required severe accident measures and needed safety evaluation to show their effectiveness for preventing containment failure. Molten corium concrete interaction (CCI) could produce large amount of hydrogen, carbon dioxide and carbon monoxide (CO), which would cause hydrogen explosion and CO explosion. Time dependence of accumulated mole numbers of steam, hydrogen, carbon dioxide and CO was shown by NRC's report. Steam and hydrogen were most for basaltic concrete and CO was quite dominant for limestone concrete. Observed explosions at Fukushima Daiichi Nuclear Power Station Unit 1 and Unit 3 were well reproduced by hydrogen produced by Zr water reaction and also CO by taking account of contribution of CCI. At severe accidents, possibility of hydrogen explosion and CO explosion should be evaluated since CCI could produce not only hydrogen but also CO in large amounts. (T. Tanaka)

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

    Science.gov (United States)

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

    2016-06-01

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

  18. Spherical combustion clouds in explosions

    Science.gov (United States)

    Kuhl, A. L.; Bell, J. B.; Beckner, V. E.; Balakrishnan, K.; Aspden, A. J.

    2013-05-01

    This study explores the properties of spherical combustion clouds in explosions. Two cases are investigated: (1) detonation of a TNT charge and combustion of its detonation products with air, and (2) shock dispersion of aluminum powder and its combustion with air. The evolution of the blast wave and ensuing combustion cloud dynamics are studied via numerical simulations with our adaptive mesh refinement combustion code. The code solves the multi-phase conservation laws for a dilute heterogeneous continuum as formulated by Nigmatulin. Single-phase combustion (e.g., TNT with air) is modeled in the fast-chemistry limit. Two-phase combustion (e.g., Al powder with air) uses an induction time model based on Arrhenius fits to Boiko's shock tube data, along with an ignition temperature criterion based on fits to Gurevich's data, and an ignition probability model that accounts for multi-particle effects on cloud ignition. Equations of state are based on polynomial fits to thermodynamic calculations with the Cheetah code, assuming frozen reactants and equilibrium products. Adaptive mesh refinement is used to resolve thin reaction zones and capture the energy-bearing scales of turbulence on the computational mesh (ILES approach). Taking advantage of the symmetry of the problem, azimuthal averaging was used to extract the mean and rms fluctuations from the numerical solution, including: thermodynamic profiles, kinematic profiles, and reaction-zone profiles across the combustion cloud. Fuel consumption was limited to ˜ 60-70 %, due to the limited amount of air a spherical combustion cloud can entrain before the turbulent velocity field decays away. Turbulent kinetic energy spectra of the solution were found to have both rotational and dilatational components, due to compressibility effects. The dilatational component was typically about 1 % of the rotational component; both seemed to preserve their spectra as they decayed. Kinetic energy of the blast wave decayed due to the

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-10-11

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

  20. Explosion caused by flashing liquid in a process vessel

    International Nuclear Information System (INIS)

    An explosion occurred at a polyvinyl chloride (PVC) resin manufacturing plant. The explosion originated at an atmospheric storage vessel when it received a slurry discharge from a suspension polymerization reactor. The pressure rise caused by the uncontrolled flashing of superheated liquid vinyl chloride resulted in the complete separation of the roof from the tank shell. A cloud of vinyl chloride vapor was released and ignited resulting in a vapor cloud explosion. The accident caused significant property damage but no serious injuries. An investigation was conducted to determine the causes of the accident. It was discovered that the facility had experienced numerous overpressure incidents in the atmospheric storage vessels used as slurry tanks. Many of these incidents resulted in modest structural damage to these slurry tanks. It was determined by Exponent that the rapid flashing of residual liquid monomer present in the product slurry stream caused the earlier overpressure incidents. The facility operator did not adequately investigate or document these prior overpressure events nor did it communicate their findings to the operating personnel. Thus, the hazard of flashing liquid vinyl chloride was not recognized. The overpressure protection for the slurry tanks was based on a combination of a venting system and a safety instrumentation system (SIS). The investigation determined that neither the venting system nor the SIS was adequate to protect the slurry tank from the worst credible overpressure scenario. Fundamentally, this is because the performance objectives of the venting system and SIS were not clearly defined and did not protect against the worst credible overpressure scenario. The lessons learned from this accident include: - use prior incident data for recognizing process hazards; - identify targets vulnerable to these hazards; - explicitly define performance objectives for safeguards to protect against the worst credible overpressure scenario. The

  1. Acoustics in the Martian Atmosphere

    Science.gov (United States)

    Williams, J.-P.

    2000-10-01

    With the advent of the first attempt to deliver an acoustic microphone to the Martian surface aboard the failed Mars Polar Lander, there has been growing interests in the development of acoustic sensors to compliment scientific payloads on future spacecraft. Terrestrial scientist have been very successful in using infrasound (sound at frequencies below human detection, detect and monitor atmospheric phenomena related to weather, tornadoes, mountain waves, microbaroms, ionospheric and auroral disturbances, and meteror/fireballs, as well as anthropogenic sources such as aircraft and nuclear explosions. Sounds on Mars at the audible frequencies (20 Hz to 20 kHz) will be severely attenuated due to viscous relaxation and thermal diffusion (collectively referred to as classical attenuation) which will be much more severe in the colder, less dense Martian atmosphere. Molecular relaxation of carbon dioxide will also contribute to the sound absorption in the lower audible frequencies. Since classical attenuation increases as a function of the frequency squared, at low infrasonic frequencies ( < 10 Hz), classical attenuation becomes less significant and sound absorption in the Martian atmosphere becomes more similar to that of the terrestrial atmosphere for the same frequencies. At these longer wavelengths, geometric spreading will dominate as the source of attenuation as the acoustic energy is spread out over an ever increasing spherical wave front. This implies that infrasound (10 to 0.01 Hz) will be a useful frequency range for future acoustic sensors developed for scientific payloads delivered to the Martian surface.

  2. Canine detection odor signatures for explosives

    Science.gov (United States)

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

    1998-12-01

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

  3. Impact sensitivity test of liquid explosives

    Science.gov (United States)

    Tiutiaev, Andrei; Trebunskih, Valeri; Dolzhikov, Andrei; Zvereva, Irina

    2015-06-01

    The sensitivity of liquid explosive in the presence of gas bubbles increases many times as compared with the liquid without gas bubbles. If we consider that in the liquid as a result of convection, wave motion, shock, etc. gas bubbles are easily generated, the need to develop a method for determining sensitivity of liquid explosives to impact and a detailed study of the ignition explosives with bubbles is obvious. On a mathematical model of a single steam bubbles in the fluid theoretically considered the process of initiating explosive liquid systems to impact. For the experimental investigation, the well-known K-44 -II and the so-called appliance No. 1 were used. Instead of the metal cap in the standard method in this paper there was polyurethane foam cylindrical container with LHE, which is easily deforms by impact. A large number of tests with different liquid explosives were made. It was found that the test LHE to impact in appliance No. 1 with polyurethane foam to a large extent reflect the real mechanical sensitivity due to the small loss of impact energy on the deformation of the metal cap, as well as the best differentiation LHE sensitivity due to the higher resolution method .

  4. Electrostatic sensitivity of secondary high explosives

    Energy Technology Data Exchange (ETDEWEB)

    Campos, C.A.

    1980-06-01

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

  5. Contained fission explosion breeder reactor system

    International Nuclear Information System (INIS)

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

  6. Alarming atmospheres

    DEFF Research Database (Denmark)

    Højlund, Marie; Kinch, Sofie

    2014-01-01

    . As a response to this situation, our design artefact, the interactive furniture Kidkit, invites children to become accustomed to the alarming sounds sampled from the ward while they are waiting in the waiting room. Our design acknowledges how atmospheres emerge as temporal negotiations between the...

  7. Securing Infrastructure from High Explosive Threats

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-03-20

    Lawrence Livermore National Laboratory (LLNL) is working with the Department of Homeland Security's Science and Technology Directorate, the Transportation Security Administration, and several infrastructure partners to characterize and help mitigate principal structural vulnerabilities to explosive threats. Given the importance of infrastructure to the nation's security and economy, there is a clear need for applied research and analyses (1) to improve understanding of the vulnerabilities of these systems to explosive threats and (2) to provide decision makers with time-critical technical assistance concerning countermeasure and mitigation options. Fully-coupled high performance calculations of structural response to ideal and non-ideal explosives help bound and quantify specific critical vulnerabilities, and help identify possible corrective schemes. Experimental validation of modeling approaches and methodologies builds confidence in the prediction, while advanced stochastic techniques allow for optimal use of scarce computational resources to efficiently provide infrastructure owners and decision makers with timely analyses.

  8. Local magnitudes of small contained explosions.

    Energy Technology Data Exchange (ETDEWEB)

    Chael, Eric Paul

    2009-12-01

    The relationship between explosive yield and seismic magnitude has been extensively studied for underground nuclear tests larger than about 1 kt. For monitoring smaller tests over local ranges (within 200 km), we need to know whether the available formulas can be extrapolated to much lower yields. Here, we review published information on amplitude decay with distance, and on the seismic magnitudes of industrial blasts and refraction explosions in the western U. S. Next we measure the magnitudes of some similar shots in the northeast. We find that local magnitudes ML of small, contained explosions are reasonably consistent with the magnitude-yield formulas developed for nuclear tests. These results are useful for estimating the detection performance of proposed local seismic networks.

  9. Detection of explosives by olfactory sensory neurons.

    Science.gov (United States)

    Corcelli, Angela; Lobasso, Simona; Lopalco, Patrizia; Dibattista, Michele; Araneda, Ricardo; Peterlin, Zita; Firestein, Stuart

    2010-03-15

    The response of olfactory sensory neurons to TNT and RDX as well as to some volatile organic compounds present in the vapors of antipersonnel landmines has been studied both in the pig and in the rat. GC/MS analyses of different plastic components of six different kinds of landmines were performed in order to identify the components of the "perfume" of mines. Studies on rat olfactory mucosa were carried out with electro-olfactogram and calcium imaging techniques, while changes in the cyclic adenosine monophosphate (cAMP) levels following exposure to odorants and explosives were used as a criterion to evaluate the interaction of TNT and RDX with olfactory receptors in a preparation of isolated pig olfactory cilia. These studies indicate that chemical compounds associated with explosives and explosive devices can activate mammalian olfactory receptors. PMID:19913995

  10. Criticality safety in high explosives dissolution

    Energy Technology Data Exchange (ETDEWEB)

    Troyer, S.D.

    1997-06-01

    In 1992, an incident occurred at the Pantex Plant in which the cladding around a fissile material component (pit) cracked during dismantlement of the high explosives portion of a nuclear weapon. Although the event did not result in any significant contamination or personnel exposures, concerns about the incident led to the conclusion that the current dismantlement process was unacceptable. Options considered for redesign, dissolution tooling design considerations, dissolution tooling design features, and the analysis of the new dissolution tooling are summarized. The final tooling design developed incorporated a number of safety features and provides a simple, self-contained, low-maintenance method of high explosives removal for nuclear explosive dismantlement. Analyses demonstrate that the tooling design will remain subcritical under normal, abnormal, and credible accident scenarios. 1 fig.

  11. Criticality safety in high explosives dissolution

    International Nuclear Information System (INIS)

    In 1992, an incident occurred at the Pantex Plant in which the cladding around a fissile material component (pit) cracked during dismantlement of the high explosives portion of a nuclear weapon. Although the event did not result in any significant contamination or personnel exposures, concerns about the incident led to the conclusion that the current dismantlement process was unacceptable. Options considered for redesign, dissolution tooling design considerations, dissolution tooling design features, and the analysis of the new dissolution tooling are summarized. The final tooling design developed incorporated a number of safety features and provides a simple, self-contained, low-maintenance method of high explosives removal for nuclear explosive dismantlement. Analyses demonstrate that the tooling design will remain subcritical under normal, abnormal, and credible accident scenarios. 1 fig

  12. Deformation and Failure of Polymer Bonded Explosives

    Institute of Scientific and Technical Information of China (English)

    陈鹏万; 黄风雷; 丁雁生

    2004-01-01

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

  13. Road Foundation Improvement by Explosive Force

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A highway was constructed in Jiangxi Province, China, through mountainous area. Some sections of the highway went through valleys where a soft clay layer of 6-8.5 m deep was encountered. A new explosive method was developed and adopted for this project. In this method, blasting is used to remove and replace soft clay with crushed stones. Explosive charges are placed in the soil to be improved according to a certain pattern. Crushed stones are piled up behind the area where charges are installed. The explosion removes most of the soil in the exploded area and causes the pile of crushed stones to slide into the area where the soil is removed by blasting. A formular was suggested to calculate the charge weight used for improving a certain type of soil. The effectiveness of the method is evaluated using borehole exploration, plate load tests,and ground-probing radar tests.

  14. Magnitude determination for large underground nuclear explosions

    International Nuclear Information System (INIS)

    A method is presented for determining the local magnitudes for large underground nuclear explosions. The Gutenberg-Richter nomograph is applied to the peak amplitudes for 24 large underground nuclear explosions that took place in Nevada. The amplitudes were measured at 18 California Wood-Anderson stations located 150-810 km from the explosion epicenter. The variation of the individual station magnitudes and magnitude corrections and the variation of the average and rms error estimates in the magnitude determinations are examined with respect to distance, azimuth, and event location. The magnitude prediction capability of the Gutenberg-Richter nomograph is examined on the basis of these two criteria, and certain corrections are suggested. The azimuthal dependence of the individual station magnitudes is investigated, and corrections for the California stations are calculated. Statistical weighting schemes for two-component data are employed, and the assumptions and limitations in the use of peak amplitudes are discussed. (author)

  15. A new formal perspective on 'Cambrian explosions'.

    Science.gov (United States)

    Wallace, Rodrick

    2014-01-01

    The 'Cambrian explosion' 500 Myr ago saw a relatively sudden proliferation of organism Bauplan and ecosystem niche structure that continues to haunt evolutionary biology. Here, adapting standard methods from information theory and statistical mechanics, we model the phenomenon as a noise-driven phase transition, in the context of deep-time relaxation of current path-dependent evolutionary constraints. The result is analogous to recent suggestions that multiple 'explosions' of increasing complexity in the genetic code were driven by rising intensities of available metabolic free energy. In the absence of severe path-dependent lock-in, 'Cambrian explosions' are standard features of blind evolutionary process, representing outliers in the ongoing routine of evolutionary punctuated equilibrium. PMID:24439546

  16. Probing thermonuclear supernova explosions with neutrinos

    CERN Document Server

    Odrzywolek, A

    2010-01-01

    Aims: We present for the first time neutrino light curves and energy spectra for two representative Type Ia supernova explosion models: a pure deflagration and a delayed detonation model. Methods: Weak neutrino flux is calculated using NSE abundances convoluted with the approximate neutrino spectra of the individual nuclei. Thermal neutrino spectrum (pair+plasma) is calculated using PSNS code. Results: The two competing explosion scenarios, while producing almost identical electromagnetic output are shown to be completely different in neutrinos. We identified the following main contributors to the neutrino signal: (1) weak electron neutrino emission from electron captures (in particular on protons, Co55, and Ni56), and numerous beta-active nuclei produced by the thermonuclear flame and/or detonation front, (2) electron antineutrinos from positron captures on neutrons, and (3) the thermal emission from pair annihilation. We estimate that a pure deflagration supernova explosion at a distance of 1 kpc would trig...

  17. Explosive fragmentation of liquids in spherical geometry

    Science.gov (United States)

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

    2016-07-01

    Rapid acceleration of a spherical shell of liquid following central detonation of a high explosive causes the liquid to form fine jets that are similar in appearance to the particle jets that are formed during explosive dispersal of a packed layer of solid particles. Of particular interest is determining the dependence of the scale of the jet-like structures on the physical parameters of the system, including the fluid properties (e.g., density, viscosity, and surface tension) and the ratio of the mass of the liquid to that of the explosive. The present paper presents computational results from a multi-material hydrocode describing the dynamics of the explosive dispersal process. The computations are used to track the overall features of the early stages of dispersal of the liquid layer, including the wave dynamics, and motion of the spall and accretion layers. The results are compared with new experimental results of spherical charges surrounded by a variety of different fluids, including water, glycerol, ethanol, and vegetable oil, which together encompass a significant range of fluid properties. The results show that the number of jet structures is not sensitive to the fluid properties, but primarily dependent on the mass ratio. Above a certain mass ratio of liquid fill-to-explosive burster (F / B), the number of jets is approximately constant and consistent with an empirical model based on the maximum thickness of the accretion layer. For small values of F / B, the number of liquid jets is reduced, in contrast with explosive powder dispersal, where small F / B yields a larger number of particle jets. A hypothetical explanation of these features based on the nucleation of cavitation is explored numerically.

  18. Radioactive and Other Effects of Nuclear Explosion

    International Nuclear Information System (INIS)

    As a result of long lasting efforts of international community to definitely ban all test nuclear explosions, the Comprehensive Nuclear-Test-Ban Treaty (CTBT) was opened for signature in New York on 24 September 1996, when it was signed by 71 states, including Croatia. The State Office for Nuclear Safety (SONS) which, as an independent state regulatory authority has a responsibility for activities relating to nuclear safety, including the national authority over this Treaty, is actively engaged in CTBTO activities. The nuclear explosion causes a lot of effects (blast, thermal, radioactive, electromagnetic) which differs a lot in its nature, reach, lasting and other. The longest lasting aftermath is from the radioactive effects that cause a radioactive fallout and a lot of radioactive elements in the environment, created by the influence of a primary beam of radiation. Fission and fusion are the main source of radionuclide created by the nuclear explosion, and the longest lasting aftermaths are by the fission products, namely their offspring in natural disintegration chains. This can make contaminated areas inappropriate for life for very long periods. Even in the case of underground nuclear explosion (when underground cavity is formed with no effects on the surface), a leakage of radioactive gases through cracks is possible. A number of radionuclide is created by the neutron activation of elements naturally present in an environment, because a very strong neutron radiation appears in the moment of nuclear explosion. The abundance of particular radionuclide is a very much dependent of a place of performing nuclear explosion and a composition of soil or water in the vicinity.(author)

  19. Mechanical Model of Domestic Gas Explosion Load

    Institute of Scientific and Technical Information of China (English)

    HAN Yongli; CHEN Longzhu

    2008-01-01

    With the increase of domestic gas consumption in cities and towns in China, gas explosion accidents happened rather frequently, and many structures were damaged greatly.Rational physical design could protect structures from being destroyed, but the character of explosion load must be learned firstly by establishing a correct mechanical model to simulate vented gas explosions.The explosion process has been studied for many years towards the safety of chemical industry equipments.The key problem of these studies was the equations usually involved some adjustable parameters that must be evaluated by experimental data, and the procedure of calculation was extremely complicated, so the reliability of these studies was seriously limited.Based on these studies, a simple mathematical model was established in this paper by using energy conservation,mass conservation, gas state equation, adiabatic compression equation and gas venting equation.Explosion load must be estimated by considering the room layout; the rate of pressure rise was then corrected by using a turbulence factor, so the pressure-time curve could be obtained.By using this method, complicated calculation was avoided, while experimental and calculated results fitted fairly well.Some pressure-time curves in a typical rectangular room were calculated to investigate the influences of different ignition locations, gas thickness, concentration, room size and venting area on the explosion pressure.The results indicated that: it was the most dangerous condition when being ignited in the geometry centre of the room; the greater the burning velocity, the worse the venting effect; the larger the venting pressure, the higher the peak pressure; the larger the venting area, the lower the peak pressure.

  20. The ionospheric disturbances caused by the explosion of the Mount Tongariro volcano in 2012

    Science.gov (United States)

    Po Cheng, C.; Lin, C.; Chang, L. C.; Chen, C.

    2013-12-01

    Volcanic explosions are known to trigger acoustic waves that propagate in the atmosphere at infrasonic speeds. At ionospheric heights, coupling between neutral particles and free electrons induces variations of electron density detectable by dual-frequency Global Positioning System (GPS) measurements. In November 21 2012, the explosion of the Mount Tongariro volcano in New Zealand occurred at UT 0:20, when there were active synoptic waves passing over north New Zealand. The New Zealand dense array of Global Positioning System recorded ionospheric disturbances reflected in total electron content (TEC) ~10 minutes after the eruption, and the concentric spread of disturbances also can be observed this day. The velocity of disturbances varies from 130m/s to 700m/s. A spectral analysis of the rTEC time series shows two peaks. The larger amplitudes are centered at 800 and 1500 seconds, in the frequency range of acoustic waves and gravity waves. On the other hand, to model the rTEC perturbation created by the acoustic wave caused by the explosive eruption of the Mount Tongariro, we perform acoustic ray tracing and obtain sound speed at subionospheric height in a horizontally stratified atmosphere model (MSIS-E-90). The result show that the velocity of the disturbances is slower than sound speed range. Through using the MSIS-E-90 Atmosphere Model and Horizontal Wind Model(HWM), we obtain the vertical wave number and indicate that the gravity waves could propagate at subionospheric height for this event, suggesting that the ionospheric disturbances caused by the explosive eruption is gravity-wave type. This work demonstrates that GPS are useful for near real-time ionospheric disturbances monitoring, and help to understand the mechanism of the gravity wave caused by volcano eruption in the future.

  1. GPS Detection and Modeling of Ionospheric Waves following the 2003 Explosion of the Soufriere Hills Volcano, Montserrat

    Science.gov (United States)

    Dautermann, T.; Calais, E.; Mattioli, G. S.; Lognonné, P.

    2007-05-01

    Volcanic explosions and shallow earthquakes are known to trigger atmospheric waves that propagate at infrasonic speeds in the atmosphere. Because of the exponential decrease of atmospheric density with altitude, the wave's amplitude increases significantly as it propagates upward. Upon reaching ionospheric altitudes, coupling between neutral particles and electrons induces variations of the ionospheric electron density that are detectable by GPS measurements. We used near- and far-field GPS data from Montserrat and the other nearby islands in the Lesser Antilles to examine ionospheric perturbations following the massive dome collapse and explosion of the Soufriere Hills Volcano on July 13th 2003. The ionospheric wave was detected in the GPS- derived integrated electron content (IEC) north of the island, in an area of maximum alignment between theoretical neutral particle motion (from ray tracing) and the Earth's magnetic field, and travels at an apparent velocity consistent with sound speed. Frequency content of the IEC showed peaks at 1 mHz and 4 mHz indicating both a gravity and an acoustic component. The data are consistent with previous observations of atmospheric perturbations after volcanic explosions. To model the acoustic part of the perturbation, we utilized the raytracing equations to follow the path of the wave through the atmosphere. We then coupled the neutral disturbance to the ionosphere by integrating the continuity equation for the charge density with a Chapman electron density distribution. Summation over all ray paths yields a synthetic IEC comparable to the GPS-derived observations.

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

    Science.gov (United States)

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

    2009-06-01

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

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

    Science.gov (United States)

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

    2009-06-01

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

  4. Evaluation of ferrocyanide/nitrate explosive hazard

    International Nuclear Information System (INIS)

    Los Alamos National Laboratory agreed to assist Pacific Northwest Laboratory in the Ferrocyanide Safety Evaluation Program by helping to evaluate the explosive hazard of several mixtures of simulated ferrocyanide waste-tank sludge containing sodium nitrite and sodium nitrate. This report is an evaluation of the small-scale safety tests used to assess the safety of these materials from an explosive point of view. These tests show that these materials are not initiated by mechanical insult, and they require an external heat source before any exothermic chemical reaction can be observed

  5. THEORIES OF ROCK BREAKAGE WITH EXPLOSIVES

    Directory of Open Access Journals (Sweden)

    Vinko Škrlec

    2014-12-01

    Full Text Available The prediction and observation of the nature and dimensions of damaged zones in the surrounding rock mass and understanding the mechanisms of fracturing and crushing of the rock mass with explosives is one of the most important parameters in blasting design in order to obtain preferred granulation and reduce damaging effects of blasting on the environment. An overview of existing rock breakage theories with the energy released by the detonation of explosives is given in this paper (the paper is published in Croatian.

  6. Radiation cure of detonation transfer explosive

    International Nuclear Information System (INIS)

    The radiation cured detonation transfer plastic bonded explosive (PBX) provides the potential for achieving improvements in processability, storability, cure reproducibility, physical strength, and reliability of performance over the Navy's present injectable detonation transfer communications explosive. The composition and properties of the radiation cured system will be presented. Radiation cure of energetic materials is a relatively new process. It combines the advantages of an indefinitely long pot-life and storage life for the material mix with a very rapid cure. Neither of these features is available with conventional catalyzed thermal cure reactions. (Auth.)

  7. Expansion of Metallic Cylinders under Explosive Loading

    Directory of Open Access Journals (Sweden)

    M.S. Bola

    1992-07-01

    Full Text Available The behaviour of expanding metallic cylinders under explosive loading was studied. Using ultra high speed photography, the expansion characteristics of aluminium and copper metallic cylinders have been evaluated with different c/m ratio, and by changing the nature of high explosive. The results obtained are comparable to those predicted by the Gurney's energy and momentum balance equations. A cylinder test has been established for comparative to the metal by octol, TNT, PEK-1, baratol and composition B are calculated. The results are in close agreement with those calculated by Kury et al.

  8. Seismic explosion sources on an ice cap

    DEFF Research Database (Denmark)

    Shulgin, Alexey; Thybo, Hans

    2015-01-01

    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...

  9. Explosive-driven, high speed, arcless switch

    Science.gov (United States)

    Skogmo, Phillip J.; Tucker, Tillman J.

    1987-01-01

    An explosive-actuated, fast-acting arcless switch contains a highly conductive foil to carry high currents positioned adjacent a dielectric surface within a casing. At one side of the foil opposite the dielectric surface is an explosive which, when detonated, drives the conductive foil against the dielectric surface. A pattern of grooves in the dielectric surface ruptures the foil to establish a rupture path having a pattern corresponding to the pattern of the grooves. The impedance of the ruptured foil is greater than that of the original foil to divert high current to a load. Planar and cylindrical embodiments of the switch are disclosed.

  10. Statistical Hot Spot Model for Explosive Detonation

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, III, A L

    2005-07-14

    The Non-local Thermodynamic Equilibrium Statistical Hot Spot Model (NLTE SHS), a new model for explosive detonation, is described. In this model, the formation, ignition, propagation, and extinction of hot spots is explicitly modeled. The equation of state of the explosive mixture is treated with a non-local equilibrium thermodynamic assumption. A methodology for developing the parameters for the model is discussed, and applied to the detonation velocity diameter effect. Examination of these results indicates where future improvements to the model can be made.

  11. Statistical Hot Spot Model for Explosive Detonation

    Energy Technology Data Exchange (ETDEWEB)

    Nichols III, A L

    2004-05-10

    The Non-local Thermodynamic Equilibrium Statistical Hot Spot Model (NLTE SHS), a new model for explosive detonation, is described. In this model, the formation, ignition, propagation, and extinction of hot spots is explicitly modeled. The equation of state of the explosive mixture is treated with a nonlocal equilibrium thermodynamic assumption. A methodology for developing the parameters for the model is discussed, and applied to the detonation velocity diameter effect. Examination of these results indicates where future improvements to the model can be made.

  12. Atmospheric Neutrinos

    CERN Document Server

    Gaisser, Thomas K

    2016-01-01

    In view of the observation by IceCube of high-energy astrophysical neutrinos, it is important to quantify the uncertainty in the background of atmospheric neutrinos. There are two sources of uncertainty, the imperfect knowledge of the spectrum and composition of the primary cosmic rays that produce the neutrinos and the limited understanding of hadron production, including charm, at high energy. This paper is an overview of both aspects.

  13. Acoustic multipole source model for volcanic explosions and inversion for source parameters

    Science.gov (United States)

    Kim, Keehoon; Lees, Jonathan M.; Ruiz, Mario

    2012-12-01

    Volcanic explosions are accompanied by strong acoustic pressure disturbances in the atmosphere. With a proper source model, these acoustic signals provide invaluable information about volcanic explosion dynamics. Far-field solutions to volcanic infrasound radiation have been derived above a rigid half-space boundary, and a simple inversion method was developed based on the half-space model. Acoustic monopole and dipole sources were estimated simultaneously from infrasound waveforms. Stability of the inversion procedure was assessed in terms of variances of source parameters, and the procedure was reliable with at least three stations around the infrasound source. Application of this method to infrasound observations recorded at Tungurahua volcano in Ecuador successfully produced a reasonable range of source parameters with acceptable variances. Observed strong directivity of infrasound radiation from explosions at Tungurahua are successfully explained by the directivity of a dipole source model. The resultant dipole axis, in turn, shows good agreement with the opening direction of the vent at Tungurahua, which is considered to be the origin of the dipole source. The method is general and can be utilized to study any monopole, dipole or combined sources generated by explosions.

  14. Refined Parameters of Chelyabinsk and Tunguska Meteoroids and their Explosion Modes

    CERN Document Server

    Lobanovsky, Yury I

    2014-01-01

    This paper describes application of mathematical model that establishes relationship between parameters of celestial bodies motion in the spheres of activity of the Sun and the Earth with mass-energy characteristics of these objects and their explosion modes during destruction in the Earth atmosphere, that in turn are linked with phenomena observed on underlying surface. This model was used to calculate the characteristics of objects that caused the Chelyabinsk and Tunguska explosions with using of its trajectory parameters described in recent scientific publications (late 2013 - early 2014). It turned out that the size of Chelyabinsk meteoroid was equal to 180 - 185 meters, and its mass was close to 1.8 megatons. Energy of its explosion was equal to 57 megatons of TNT, size of Tunguska meteoroid was equal to 105 m, mass - 0.35 megatons, while energy of explosion was about of 14.5 megatons of TNT. Due to the common origin of these two celestial bodies their average density was equal - about of 570 kg/m^3.

  15. Horizontal dimensions of ionosphere agitation provoked by underground nuclear explosions

    International Nuclear Information System (INIS)

    The horizontal dimensions of ionosphere agitation provoked by underground nuclear explosions have been experimentally determined for 13 explosions conducted at the Balapan test site of the Semipalatinsk test site. (author)

  16. Contamination mechanisms of air basin with tritium in venues of underground nuclear explosions at the former Semipalatinsk test site

    International Nuclear Information System (INIS)

    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”. - Highlights: ► The basic mechanisms for tritium distribution in the air of nuclear testing sites were examined. ► We researched the distribution of tritium in the systems such as water–atmosphere, tunnel air–atmosphere, soil water–atmosphere and vegetation–atmosphere. ► An analytical calculation of tritium concentration in the atmosphere was performed. ► We experimentally obtained the dependence for predictive assessment of tritium concentrations in

  17. Incremental Pressing Technique in Explosive Charge

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A pressing technique has become available that might be useful for compressing granular explosives. If the height-diameter ratio of the charge is unfavorable,the high quality charge can not be obtained with the common single-action pressing. This paper presents incremental pressing technique, which can obtain the charge with higher overall density and more uniform density.

  18. Multiphase Instabilities in Explosive Dispersal of Particles

    Science.gov (United States)

    Rollin, Bertrand; Ouellet, Frederick; Annamalai, Subramanian; Balachandar, S. ``Bala''

    2015-11-01

    Explosive dispersal of particles is a complex multiphase phenomenon that can be observed in volcanic eruptions or in engineering applications such as multiphase explosives. As the layer of particles moves outward at high speed, it undergoes complex interactions with the blast-wave structure following the reaction of the energetic material. Particularly in this work, we are interested in the multiphase flow instabilities related to Richmyer-Meshkov (RM) and Rayleigh-Taylor (RM) instabilities (in the gas phase and particulate phase), which take place as the particle layer disperses. These types of instabilities are known to depend on initial conditions for a relatively long time of their evolution. Using a Eulerian-Lagrangian approach, we study the growth of these instabilities and their dependence on initial conditions related to the particulate phase - namely, (i) particle size, (ii) initial distribution, and (iii) mass ratio (particles to explosive). Additional complexities associated with compaction of the layer of particles are avoided here by limiting the simulations to modest initial volume fraction of particles. A detailed analysis of the initial conditions and its effects on multiphase RM/RT-like instabilities in the context of an explosive dispersal of particles is presented. This work was supported by the U.S. Department of Energy, National Nuclear Security Administration, Advanced Simulation and Computing Program, as a Cooperative Agreement under the Predictive Science Academic Alliance Program, Contract No. DE-NA0002378.

  19. New Dark Matter Detector using Nanoscale Explosives

    CERN Document Server

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

    2014-01-01

    We present nanoscale explosives as a novel type of dark matter detector and study the ignition properties. When a Weakly Interacting Massive Particle WIMP from the Galactic Halo elastically scatters off of a nucleus in the detector, the small amount of energy deposited can trigger an explosion. For specificity, this paper focuses on a type of two-component explosive known as a nanothermite, consisting of a metal and an oxide in close proximity. When the two components interact they undergo a rapid exothermic reaction --- an explosion. As a specific example, we consider metal nanoparticles of 5 nm radius embedded in an oxide. One cell contains more than a few million nanoparticles, and a large number of cells adds up to a total of 1 kg detector mass. A WIMP interacts with a metal nucleus of the nanoparticles, depositing enough energy to initiate a reaction at the interface between the two layers. When one nanoparticle explodes it initiates a chain reaction throughout the cell. A number of possible thermite mat...

  20. Shock-Wave Behavior in Explosive Monocrystals

    OpenAIRE

    Dick, J.

    1995-01-01

    The shock response of explosive monocrystals is strongly anisotropic. Shock initiation sensitivity depends strongly on crystal orientation in PETN. This can be understood in terms of steric hindrance to shear during the shock-induced deformation of the molecular crystal. This initiation mechanism appears to be tribochemical rather than thermal. Related work by other researchers is also discussed.

  1. 78 FR 1143 - Explosive Siting Requirements; Correction

    Science.gov (United States)

    2013-01-08

    ... correcting a final rule published on September 7, 2012 (77 FR 55108). In that rule, the FAA amended its... Siting Requirements'' (77 FR 55108). In that final rule, the FAA revised the requirements for siting... Federal Aviation Administration 14 CFR Part 420 RIN 2120-AJ73 Explosive Siting Requirements;...

  2. 77 FR 55108 - Explosive Siting Requirements

    Science.gov (United States)

    2012-09-07

    ... and Explosives Safety Standards, 70 FR 24771 (May 11, 2005) (2004 DOD Standard). DOD released a new... Requirements, 76 FR 8923 (Feb. 16, 2011). The FAA is making a number of changes consistent with the goals of Executive Order 13610, Identifying and Reducing Regulatory Burdens, 77 FR 28469 (May 14, 2012). First,...

  3. The nature of explosive percolation phase transition

    International Nuclear Information System (INIS)

    In this Letter, we show that the explosive percolation is a novel continuous phase transition. The order-parameter-distribution histogram at the percolation threshold is studied in Erdős–Rényi networks, scale-free networks, and square lattice. In finite system, two well-defined Gaussian-like peaks coexist, and the valley between the two peaks is suppressed with the system size increasing. This finite-size effect always appears in typical first-order phase transition. However, both of the two peaks shift to zero point in a power law manner, which indicates the explosive percolation is continuous in the thermodynamic limit. The nature of explosive percolation in all the three structures belongs to this novel continuous phase transition. Various scaling exponents concerning the order-parameter-distribution are obtained. -- Highlights: ► The explosive percolation is a novel continuous phase transition. ► The order-parameter-distribution histogram at the percolation threshold is studied. ► Two well-defined peaks coexist, and the valley in between is suppressed. ► However, both of the two peaks shift to zero point in a power law manner. ► Various scaling exponents concerning the order-parameter-distribution are obtained.

  4. Modeling Astrophysical Explosions with Sustained Exascale Computing

    CERN Document Server

    Zingale, M; Malone, C M; Timmes, F X

    2015-01-01

    Our understanding of stars and their fates is based on coupling observations to theoretical models. Unlike laboratory physicists, we cannot perform experiments on stars, but rather must patiently take what nature allows us to observe. Simulation offers a means of virtual experimentation, enabling a detailed understanding of the most violent ongoing explosions in the Universe---the deaths of stars.

  5. Magic nuclei at explosive dynamo activity

    Directory of Open Access Journals (Sweden)

    Kondratyev V. N.

    2016-01-01

    Full Text Available Explosive nucleosynthesis at conditions of magnetorotational instabilities is considered for iron group nuclides by employing arguments of nuclear statistical equilibrium. Effects of ultra-strong nuclear magnetization are demonstrated to enhance the portion of titanium product. The results are corroborated with an excess of 44Ti revealed from the Integral mission data.

  6. Electromagnetic signals from underground nuclear explosions

    International Nuclear Information System (INIS)

    Electromagnetic fields and ground currents resulting from underground nuclear explosions have been observed since the first such event. A few measurements have been reported, but most have not. There also have been some speculations as to their origin; the two most generally proposed are the magnetic bubble and the seismoelectric effect. The evidence seems to favor the latter mechanism. 15 refs., 36 figs

  7. Fragmentation requirements for detonating thermal explosions

    International Nuclear Information System (INIS)

    The mechanism of thermal explosions, which are of interest when evaluating nuclear reactor safety factors, is considered. Such explosions are caused by the contact of a hot with a cold liquid developing into a rapid thermal interaction in which a significant fraction (approaching the thermodynamic limits) of the thermal energy in the hot liquid is converted into mechanical work. Board et al (Nature; 254:319 (1975)) proposed the use of classical detonation theory in conjunction with a mechanism of pressure wave-induced fragmentation of liquid fuel drops premixed (coarsely) with the liquid coolant, the quantitative aspects of which were based on existing measurements in gas-water systems as an approach to understanding such explosions. Here, studies of fragmentation of high surface tension liquid drops (mercury) in a liquid medium (water) in which it was found that the fragmentation behaviour is considerably different from that in the gas-water system are reported. The results reveal a different behaviour than that expected from previous work and it is shown that the pressure pulse trigger requirements for the detonation model proposed by Board et al are drastically reduced compared with the original estimates of those workers. It is emphasised that fragmentation is only one aspect of the explosion process and suggestions are made of other mechanisms which must be investigated in order to assess the conditions of applicability of the detonation model. (U.K.)

  8. Foudre et atmosphères explosives

    OpenAIRE

    Halama, Stanislas

    1997-01-01

    De nombreuses installations industrielles a risques le sont du fait de l'utilisation de produits sensibles pouvant provoquer facilement des incendies et des explosions. C'est te cas des industries et entrepots qui transforment, fabriquent, manipulent et stockent des produits inflammables.

  9. High power electrical wire explosion in water

    International Nuclear Information System (INIS)

    Full Text:Experimental and magneto-hydro-dynamic simulation results of nanosecond time scale underwater electrical Al, Cu and W wires explosions are presented. A water forming line generator with current amplitude up to 100 kA was used. Maximal current rise rate and maximal Joule heating power achieved during wire explosions were 500 Ga/s and 6 GW, respectively. Extremely high energy deposition of up to 60 times the atomization enthalpy was registered comparing to the best reported result of energy deposition obtained in vacuum wire explosion of 20 times the atomization enthalpy. A discharge channel evolution and surface temperature were analyzed by streak shadow imaging and using fast photo-diode with a set of interference filters, respectively. A 1D magneto-hydro-dynamic simulation demonstrated good agreement with such experimental parameters as discharge channel current, voltage, radius, and temperature. Material conductivity has been calculated to produce best correlation of the simulated and experimentally obtained voltage. It has been shown that conductivity may significantly vary as a function of energy deposition rate in nanosecond time scale underwater electrical wire explosions

  10. Java: An Explosion on the Internet.

    Science.gov (United States)

    Read, Tim; Hall, Hazel

    Summer 1995 saw the release, with considerable media attention, of draft versions of Sun Microsystems' Java computer programming language and the HotJava browser. Java has been heralded as the latest "killer" technology in the Internet explosion. Sun Microsystems and numerous companies including Microsoft, IBM, and Netscape have agreed upon…

  11. Explosion of Ultrahigh Pressure Minerals in Mantle

    Institute of Scientific and Technical Information of China (English)

    BAI Wenji; YANG Jingsui; FANG Qingsong; YAN Binggang; ZHANG Zhongming

    2001-01-01

    @@ The microexplosion stucture of ultrahigh pressure minerals was found for the first time in podform chromitites within the mantle peridotite facies of Luobusa ophiolite along the Yarlung Zangbo suture zone.The explosion stuctures of high-energy silicate inclusions are commonly seen in thin sections (see figure).

  12. Developments in vapour cloud explosion blast modeling

    NARCIS (Netherlands)

    Mercx, W.P.M.; Berg, A.C. van den; Hayhurst, C.J.; Robertson, N.J.; Moran, K.C.

    2000-01-01

    TNT Equivalency methods are widely used for vapour cloud explosion blast modeling. Presently, however, other types of models are available which do not have the fundamental objections TNT Equivalency models have. TNO Multi-Energy method is increasingly accepted as a more reasonable alternative to be

  13. Explosives Classifications Tracking System User Manual

    Energy Technology Data Exchange (ETDEWEB)

    Genoni, R.P.

    1993-10-01

    The Explosives Classification Tracking System (ECTS) presents information and data for U.S. Department of Energy (DOE) explosives classifications of interest to EM-561, Transportation Management Division, other DOE facilities, and contractors. It is intended to be useful to the scientist, engineer, and transportation professional, who needs to classify or transport explosives. This release of the ECTS reflects upgrading of the software which provides the user with an environment that makes comprehensive retrieval of explosives related information quick and easy. Quarterly updates will be provided to the ECTS throughout its development in FY 1993 and thereafter. The ECTS is a stand alone, single user system that contains unclassified, publicly available information, and administrative information (contractor names, product descriptions, transmittal dates, EX-Numbers, etc.) information from many sources for non-decisional engineering and shipping activities. The data is the most up-to-date and accurate available to the knowledge of the system developer. The system is designed to permit easy revision and updating as new information and data become available. These, additions and corrections are welcomed by the developer. This user manual is intended to help the user install, understand, and operate the system so that the desired information may be readily obtained, reviewed, and reported.

  14. Some properties of explosive mixtures containing peroxides

    International Nuclear Information System (INIS)

    This study concerns mixtures of triacetone triperoxide (3,3,6,6,9,9-hexamethyl-1,2,4,5,7,8-hexoxonane, TATP) and ammonium nitrate (AN) with added water (W), as the case may be, and dry mixtures of TATP with urea nitrate (UN). Relative performances (RP) of the mixtures and their individual components, relative to TNT, were determined by means of ballistic mortar. The detonation energies, E0, and detonation velocities, D, were calculated for the mixtures studied by means of the thermodynamic code CHEETAH. Relationships have been found and are discussed between the RP and the E0 values related to unit volume of gaseous products of detonation of these mixtures. These relationships together with those between RP and oxygen balance values of the mixtures studied indicate different types of participation of AN and UN in the explosive decomposition of the respective mixtures. Dry TATP/UN mixtures exhibit lower RP than analogous mixtures TATP/AN containing up to 25% of water. Depending on the water content, the TATP/AN mixtures possess higher detonability values than the ANFO explosives. A semi-logarithmic relationship between the D values and oxygen coefficients has been derived for all the mixtures studied at the charge density of 1000 kg m-3. Among the mixtures studied, this relationship distinguishes several samples of the type of 'tertiary explosives' as well as samples that approach 'high explosives' in their performances and detonation velocities

  15. A Study of the behaviour of emulsion explosives

    OpenAIRE

    J. Allum

    2009-01-01

    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...

  16. CFD simulation of vented explosion and turbulent flame propagation

    Directory of Open Access Journals (Sweden)

    Tulach Aleš

    2015-01-01

    Full Text Available Very rapid physical and chemical processes during the explosion require both quality and quantity of detection devices. CFD numerical simulations are suitable instruments for more detailed determination of explosion parameters. The paper deals with mathematical modelling of vented explosion and turbulent flame spread with use of ANSYS Fluent software. The paper is focused on verification of preciseness of calculations comparing calculated data with the results obtained in realised experiments in the explosion chamber.

  17. CFD simulation of vented explosion and turbulent flame propagation

    Science.gov (United States)

    Tulach, Aleš; Mynarz, Miroslav; Kozubková, Milada

    2015-05-01

    Very rapid physical and chemical processes during the explosion require both quality and quantity of detection devices. CFD numerical simulations are suitable instruments for more detailed determination of explosion parameters. The paper deals with mathematical modelling of vented explosion and turbulent flame spread with use of ANSYS Fluent software. The paper is focused on verification of preciseness of calculations comparing calculated data with the results obtained in realised experiments in the explosion chamber.

  18. Integrated control system for nuclear explosives

    International Nuclear Information System (INIS)

    The Integrated Control System (ICS) has been developed to facilitate Plowshare nuclear detonations by following a unified system approach. This system consolidates the techniques for firing, safety program, scientific program, and communications. Maximum emphasis is placed upon control and data transmission by radio rather than hardwire or coaxial cable. The ICS consists of a Command Point (CP) Trailer, a radio repeater station, a field station (the ICE Box), and several chassis located in the explosive canister. Commands originate in the CP and are transmitted via microwave radio to the ICE Box; monitors are returned to the CP from the canister, the ICE Box, and sensors near ground zero. The system allows complete checkout and operation before shipment to the field. The explosive canister may be dry-run at the assembly area (at NTS) before shipment to the field. The basic detonation functions for every event are: 1. Arming and firing commands in the explosive canister and at surface ground zero. 2. Environmental monitors and suitable arming monitors in the explosive canister. 3. Safety monitors at the zero site for weather, RAMS (Remote Area Monitoring System), and cavity collapse. Secondary functions that may be required for a specific project are: 4. Scientific program of phenomenology measurements. 5. Explosive performance measurements. 6. Ground zero television. 7. Auxiliary communications such as local telephones, VHF radio. By combining functions that have previously been performed by separate organizations and systems, the ICS attempts a minimum cost detonation service. Economy of operation results because: 1. Operating personnel work on more than one sub-system. 2. Interfaces and interface complexity are minimized. 3. A reduced dependence upon signal cables results from a microwave-based system. 4. Pre-fabrication allows test operation before shipment to the field and minimizes setup time in the field. The ICS is in use on the Sturtevant event and is

  19. 30 CFR 19.7 - Protection against explosion hazard.

    Science.gov (United States)

    2010-07-01

    ... 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...

  20. Explosive-train initiated through solid bulkhead by pressure cartridge

    Science.gov (United States)

    Wilkowski, J. C.

    1968-01-01

    Explosive-train initiated pressure cartridge transmits a shock wave igniting a main charge of explosive through a solid bulkhead without destroying or damaging the seal or the bulkhead. The main charge could be an explosive, a pyrotechnic, or a propellant.

  1. Increase of water resistance of ammonium nitrate explosives

    Directory of Open Access Journals (Sweden)

    Zulkhair Mansurov

    2012-03-01

    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.

  2. 30 CFR 57.6960 - Mixing of explosive material.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Mixing of explosive material. 57.6960 Section... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives General Requirements-Underground Only § 57.6960 Mixing of explosive material. (a) The mixing...

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

    International Nuclear Information System (INIS)

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

  4. 40 CFR 258.23 - Explosive gases control.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Explosive gases control. 258.23... FOR MUNICIPAL SOLID WASTE LANDFILLS Operating Criteria § 258.23 Explosive gases control. (a) Owners or... facility does not exceed 25 percent of the lower explosive limit for methane in facility...

  5. 49 CFR 172.320 - Explosive hazardous materials.

    Science.gov (United States)

    2010-10-01

    ... required by regulations for commercial explosives specified in 27 CFR part 555, if the national stock... 49 Transportation 2 2010-10-01 2010-10-01 false Explosive hazardous materials. 172.320 Section 172... REQUIREMENTS, AND SECURITY PLANS Marking § 172.320 Explosive hazardous materials. (a) Except as...

  6. 30 CFR 57.6905 - Protection of explosive material.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Protection of explosive material. 57.6905... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives General Requirements-Surface and Underground § 57.6905 Protection of explosive material. (a)...

  7. 30 CFR 57.20009 - Tests for explosive dusts.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tests for explosive dusts. 57.20009 Section 57.20009 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... § 57.20009 Tests for explosive dusts. Dusts suspected of being explosive shall be tested...

  8. 30 CFR 56.20009 - Tests for explosive dusts.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tests for explosive dusts. 56.20009 Section 56.20009 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL....20009 Tests for explosive dusts. Dusts suspected of being explosive shall be tested for...

  9. Dimensional analysis for the mechanical effects of some underground explosions

    International Nuclear Information System (INIS)

    The influence of the medium properties upon the effects of underground nuclear and high explosive explosions is studied by dimensional analysis methods. A comparison is made with the experimental data from the Hoggar contained nuclear shots, specially with the particle motion data and the cavity radii. Furthermore, for example, crater data from explosions in Nevada have been examined by statistical methods. (author)

  10. Explosive limits and its container factors of polybasic explosive mixture gas containing H2, CH4 and CO

    Institute of Scientific and Technical Information of China (English)

    胡耀元; 李勇; 朱凯汉; 周邦智; 杨元法

    2002-01-01

    Explosive characteristics of polybasic explosive mixture gas are systematically researched. Over 28000 experimental data have been obtained from 1278 effective experiments. The paper probes into the concentration explosive limits and the container factors of polybasic explosive mixture gas which contains H2, CH4 and CO. It has worked out the sufficient and necessary condition for branch-chain explosion and the unified expression of the probability of the heterogeneous chain termination. Experiments indicate that the concentration explosive limits of polybasic explosive mixture gas (H2, CH4, CO) relate to many factors. They enlarge with the augmentability of the container (linear size, geometric shape, and flame spread direction). This will be of great significance to guiding the revision of related industrial safety targets, reclaiming and reusing related industrial tail gas and waste gas, taking precautions against the explosion hazard of mixture gas in correlated industry and mines, and applying the br

  11. Measurement of Afterburning Effect of Underoxidized Explosives by Underwater Explosion Method

    Science.gov (United States)

    Cao, Wei; He, Zhongqi; Chen, Wanghua

    2015-04-01

    The afterburning effect of TNT and a desensitized hexogen RDX-Al explosive was studied in a defined gas volume under water. A double-layer container (DLC) filled with different gases (air, oxygen, and nitrogen) was used to control and distinguish the afterburning effect of explosives. After the charges in the DLC were initiated under water, the shock wave signals were collected and analyzed. It is shown that shock wave peak pressures are duly in compliance with explosion similarity law, pressure, and impulse histories for explosions in oxygen and air are greater than those recorded for explosions in nitrogen due to the afterburing reaction. Moreover, the afterburning energy was calculated. Results show that even though there is excess oxygen in the gas volume, the afterburning energy may not reach the theoretically maximum value. This result is different from that in confined explosion, where the presence of excess oxygen in the compressed gas filling a bomb leads to complete combustion of the detonation products.

  12. Plutonium explosive dispersal modeling using the MACCS2 computer code

    International Nuclear Information System (INIS)

    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

  13. The dispersal of ash during explosive eruptions from central volcanoes and calderas: an underestimated hazard for the central Mediterranean area

    International Nuclear Information System (INIS)

    The central Mediterranean area comprises some of the most active volcanoes of the northern hemisphere. Some of their names recall myths or events in human history: Somma-Vesuvius, Etna, Stromboli, Vulcano, Ischia and Campi Flegrei. These volcanoes are still active today, and produce both effusive and explosive eruptions. In particular, explosive eruptions can produce and disperse large amount of volcanic ash, which pose a threat to environment, economy and human health over a large part of the Mediterranean area. We present and discuss data of ash dispersal from some explosive eruptions of southern Italy volcanoes, which dispersed centimetre -thick ash blankets hundred of kilometres from the source, irrespective of the more limited dispersal of the respective coarse grained fallout and PDC deposits. The collected data also highlight the major role played by lower atmosphere winds in dispersal of ash from weak plumes and ash clouds that accompany PDC emplacement.

  14. Disturbances in the lower ionosphere caused by a low altitude nuclear explosion

    Science.gov (United States)

    Xunjie, Zhang; Xueqin, Ruan; Wenzhen, Wang

    1995-03-01

    Observations of the lower ionospheric disturbance caused by a low altitude nuclear explosion are presented. A forward scatter radar, frequency 41 MHz, power 2.5 kW, was used to study these disturbances. The first radar scattering signal consisting of three peaks appeared 40 s after the explosion. It was due to early ionization by delayed gamma rays. The second kind of disturbance generated after 190 s was clearly different from the first. The scattering signal had a constant component which indicated a strong specular reflection. The field strength increased by more than 20 db. This disturbance was produced by the direct shock wave. The third kind of disturbance began after 8 min, lasted 5.0 min, and was probably dominated by the fireball/smoke cloud oscillation when it reached its stabilization altitude and approached hydrodynamical equilibrium with the ambient atmosphere. Using numerical computation techniques, we have explained the above results well.

  15. Explosive action parabolic lenses with the fields of 0,3-1 MOe

    International Nuclear Information System (INIS)

    Test results of explosive action parabolic lenses are presented. The following problems have been posed: clarification of the maximum permissible fields which don't cause the destruction in lenses with a neck; investigation into lense deformation and destruction in the explosive regime in two versions: lenses with contacting current surfaces and lenses with an insulation gap combining functions of lens and spark gap development of the design of current leads and busbar arrangement with semi-automatic replacement of fractured elements. Feeding of the lenses by 1-1.5 MA current has been performed by discharge of low-inductive capacitor batteries. Deformation of aluminium- and duralumin lenses is shown to proceed differently. Aluminium lenses essentially expand before fracture, and the pressurized volume communicates with atmosphere in 8-10 μs. In duralumin lenses this time is approximately twice as low. Design of the operating version of the busbar arengement is described

  16. 30 CFR 77.1909 - Explosives and blasting; use of permissible explosives and shot-firing units.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Explosives and blasting; use of permissible explosives and shot-firing units. 77.1909 Section 77.1909 Mineral Resources MINE SAFETY AND HEALTH... blasting; use of permissible explosives and shot-firing units. Except as provided in § 77.1909-1,...

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

    Energy Technology Data Exchange (ETDEWEB)

    Reed, J.W.

    1988-11-01

    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.

  18. Multiparametric Geophysical Signature of Vulcanian Explosions

    Science.gov (United States)

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

    2010-12-01

    Extrusion of viscous magma leading to lava dome-formation is a common phenomenon at arc volcanoes recently demonstrated at Mount St. Helens (USA), Chaiten (Chile), and SoufriËre Hills Volcano (British West Indies). The growth of lava domes is frequently accompanied by vigorous eruptions, commonly referred to as Vulcanian-style, characterized by sequences of short-lived (tens of seconds to tens of minutes) explosive pulses, reflecting the violent explosive nature of arc volcanism. Vulcanian eruptions represent a significant hazard, and an understanding of their dynamics is vital for risk mitigation. While eruption parameters have been mostly constrained from observational evidence, as well as from petrological, theoretical, and experimental studies, our understanding on the physics of the subsurface processes leading to Vulcanian eruptions is incomplete. We present and interpret a unique set of multi-parameter geophysical data gathered during two Vulcanian eruptions in July and December, 2008 at SoufriËre Hills Volcano from seismic, geodetic, infrasound, barometric, and gravimetric instrumentation. These events document the spectrum of Vulcanian eruptions in terms of their explosivity and nature of erupted products. Our analysis documents a pronounced difference in the geophysical signature of the two events associated with priming timescales and eruption triggering suggesting distinct differences in the mechanics involved. The July eruption has a signature related to shallow conduit dynamics including gradual system destabilisation, syn-eruptive decompression of the conduit by magma fragmentation, conduit emptying and expulsion of juvenile pumice. In contrast, sudden pressurisation of the entire plumbing system including the magma chambers resulted in dome carapace failure, a violent cannon-like explosion, propagation of a shock wave and pronounced ballistic ejection of dome fragments. We demonstrate that with lead times of between one and six minutes to the

  19. Nucleosynthetic Signatures of Asymmetric Supernovae - Lessons from 1-dimensional Explosions

    International Nuclear Information System (INIS)

    We review the evidence for asymmetries in explosions, and in particular, the nucleosynthetic signatures from these asymmetries. To guide our intuition for these yields, we have modeled a series of spherically symmetric explosions with a range of explosion energies. Here we present the results from these 1-dimensional simulations, focusing on the yields of the radioactive elements 44Ti and 56Ni. We find that, although the abundance yields of 44Ti do depend sensitively on the explosion energy, the trend (whether it increases or decreases with explosion energy) depends very sensitively on the model

  20. Nucleosynthetic Signatures of Asymmetric Supernovae - Lessons from 1-dimensional Explosions

    Science.gov (United States)

    Hungerford, A. L.; Fryer, C. L.; Timmes, F. X.; McGhee, K.

    2005-07-01

    We review the evidence for asymmetries in explosions, and in particular, the nucleosynthetic signatures from these asymmetries. To guide our intuition for these yields, we have modeled a series of spherically symmetric explosions with a range of explosion energies. Here we present the results from these 1-dimensional simulations, focusing on the yields of the radioactive elements 44Ti and 56Ni. We find that, although the abundance yields of 44Ti do depend sensitively on the explosion energy, the trend (whether it increases or decreases with explosion energy) depends very sensitively on the model.

  1. The effect of duct surface character on methane explosion propagation

    Institute of Scientific and Technical Information of China (English)

    LIN Bai-quan; YE Qing; JIAN Cong-guang; WU Hai-jin

    2007-01-01

    The effect of duct surface character on methane explosion propagation was experimentally studied and theoretically analyzed. The roughness has effect on methane explosion propagation. The flame propagation velocity and the peak value pressure of methane explosion in rough duct are larger than the parameters in smooth duct. The heat exchange of the surface has effect on methane explosion propagation. The propagation velocity of flame and strength of explosion wave in the duct covered by heat insulation material are larger than those in duct with good heat transmittability.

  2. DOE TMD transportation training module 14 transportation of explosives

    Energy Technology Data Exchange (ETDEWEB)

    Griffith, R.L. Jr.

    1994-07-01

    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.

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

    Science.gov (United States)

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

    2015-04-01

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

  4. Numerical analysis of welded joint treated by explosion shock waves

    Institute of Scientific and Technical Information of China (English)

    GUAN Jianjun; CHEN Huaining

    2007-01-01

    This paper focuses on the simulation of welding residual stresses and the action of explosion shock waves on welding residual stresses. Firstly, the distributions of welding temperature field and residual stress on a butt joint were numerically simulated with the sequentially coupled method. Secondly, the effect of explosion shock waves, produced by plastic strip-like explosive, on welding residual stress distri-bution was predicted with coupled Lagrange-ALE algorithm.It was implicated that explosion treatment could effectively reduce welding residual stresses. The simulation work lays a foundation for the further research on the rule of explosion treatment's effect on welding residual stresses and the factors that may influence it.

  5. Explosives vapour identification in ion mobility spectrometry using a tunable laser ionization source: a comparison with conventional {sup 63}Ni ionization

    Energy Technology Data Exchange (ETDEWEB)

    Clark, A.; Deas, R.M.; Kosmidis, C.; Ledingham, K.W.D.; Marshall, A.; Singhal, R.P. [Glasgow Univ. (United Kingdom). Dept. of Physics and Astronomy

    1995-03-01

    Laser multiphoton ionization (MPI) is used to produce ions from explosive vapours at atmospheric pressure in air for analysis by ion mobility spectrometry (IMS). In the positive ion mode of detection, NO{sup +} ions, generated directly by multiphoton dissociation/ionization of the explosive compounds, show strong variation with laser wavelength. This provides a means of identifying the presence of nitro-containing compounds. Moreover, electrons formed in the MPI of gaseous components in the air carrier stream, primarily O{sub 2}, are transferred via neutral molecular oxygen (O{sub 2}) to trace explosive vapour, forming negative ions which give rise to characteristic and identifiable ion mobility spectra. Further, negative ion mobility spectra of several explosive vapours are presented using conventional {sup 63}Ni ionization and are compared qualitatively with the laser ionization approach. (author).

  6. Inelastic processes in seismic wave generation by underground explosions

    International Nuclear Information System (INIS)

    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

  7. Explosive Eruptions of Kamchatkan Volcanoes in 2012 and Danger to Aviation

    Science.gov (United States)

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

    2013-04-01

    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

  8. Explosion and fire analysis of the Dora gas storage tanks

    International Nuclear Information System (INIS)

    Full text.The location of the Dora natural gas storage tanks within a close proximity to densely populated areas necessitates a thorough study of the risk associated with accidental gas releases and potential subsequent explosions. This paper describes the type and mechanism of release, the explosion form, the ensuing severity and the areas that are correspondingly affected. A variety of leakage scenarios are explored using mathematical models that simulate gas discharge, liquid leaks and two-phase gaseous and liquid streams. Relevant explosion models are discussed covering confined explosions, unconfined vapor cloud explosions, boiling liquid expanding vapor explosions and pool fires including the identification of the elements necessary for fire initiation. Fire explosion damages and influencing factors are then presented with the purpose of effecting a thorough reflection on damage extent. Finally, hazard control programs are defined on the basis of hazard priorities among the likely scenarios

  9. Insensitive detonator apparatus for initiating large failure diameter explosives

    Science.gov (United States)

    Perry, III, William Leroy

    2015-07-28

    A munition according to a preferred embodiment can include a detonator system having a detonator that is selectively coupled to a microwave source that functions to selectively prime, activate, initiate, and/or sensitize an insensitive explosive material for detonation. The preferred detonator can include an explosive cavity having a barrier within which an insensitive explosive material is disposed and a waveguide coupled to the explosive cavity. The preferred system can further include a microwave source coupled to the waveguide such that microwaves enter the explosive cavity and impinge on the insensitive explosive material to sensitize the explosive material for detonation. In use the preferred embodiments permit the deployment and use of munitions that are maintained in an insensitive state until the actual time of use, thereby substantially preventing unauthorized or unintended detonation thereof.

  10. Sensitive analysis of fuel drop diameter in vapor explosions

    International Nuclear Information System (INIS)

    Background: In nuclear plant vapor explosion analysis, fuel drop diameter is an important parameter which could significantly influence the evaluation of explosion pressure. Purpose: Decrease the uncertainty of vapor explosion calculation caused by fuel drop diameter. Methods: A simulation model of typical vapor explosion was built using MC3D to take sensitive analysis of fuel drop diameter. Results: The calculation relates to fuel drop energy, fuel drop fragmentation rate and vapor explosion pressure. The effect of fuel drop diameter in vapor explosion is analyzed based on theoretical analysis and the calculation. Conclusions: The results show that the vapor explosion pressure is very sensitive to fuel drop diameter, which is mainly caused by the fuel drop energy and the fuel drop fragmentation rate. (authors)

  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)

    2014-11-12

    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. 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

    2013-06-01

    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.

  13. Sub-photospheric shocks in relativistic explosions

    CERN Document Server

    Beloborodov, Andrei M

    2016-01-01

    This paper examines the mechanism of shocks in opaque outflows from astrophysical explosions, in particular in cosmological gamma-ray bursts. Sub-photospheric shocks can produce neutrino emission and affect the observed photospheric radiation from the explosion. Shocks develop from internal compressive waves and can be of different types depending on the composition of the flow: (1) Shocks in `photon gas' with small plasma inertial mass have a unique structure determined by the `force-free' condition -- zero radiation flux in the plasma rest frame. Radiation dominance over plasma inertia suppresses formation of collisionless shocks mediated by collective electromagnetic fields. (2) Strong collisionless subshocks develop in the opaque flow if it is sufficiently magnetized. We evaluate the critical magnetization for this to happen. The collisionless subshock is embedded in a thicker radiation-mediated shock structure. (3) Shocks in outflows carrying a free neutron component involve dissipation through nuclear c...

  14. Explosive magnetorotational instability in Keplerian disks

    CERN Document Server

    Shtemler, Yu; Mond, M

    2016-01-01

    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 a MRI mode with stable Alfv\\'en-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.

  15. Signatures of nucleosynthesis in explosive stellar processes.

    Science.gov (United States)

    Wiescher, M.

    This paper presents a discussion of the characteristic observables of stellar explosions and compares the observed signatures such as light curve and abundance distribution with the respective values predicted in nucleosynthesis model calculations. Both the predicted energy generation as well as the abundance distribution in the ejecta depends critically on the precise knowledge of the reaction rates and decay processes involved in the nucleosynthesis reaction sequences. The important reactions and their influence on the production of the observed abundances will be discussed. The nucleosynthesis scenarios presented here are all based on explosive events at high temperature and density conditions. Many of the nuclear reactions involve unstable isotopes and are not well understood yet. To reduce the experimental uncertainties several radioactive beam experiments will be dicussed which will help to come to a better understanding of the correlated nucleosynthesis.

  16. Pipelines explosion, violates Humanitarian International Right

    International Nuclear Information System (INIS)

    Recently and for first time, an organism of the orbit of the human rights put the finger in the wound of the problem that represents for Colombia the pipelines explosion and the social and environmental impact that those actions in this case the Defense of the People office, the institution that published a document related this denounces, in the one that sustains that the country it cannot continue of back with a serious and evident reality as the related with the explosions of pipelines. We are the only country of the world where happen these facts and enormous losses are not only causing to the Colombian economy, but rather our environmental wealth is affecting, the document, denounced the ignorance of the humanitarian international right on the part of those who apply to that class of attacks

  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.

    1998-01-01

    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. Neutron albedo effects of underground nuclear explosion

    International Nuclear Information System (INIS)

    The neutron field distribution is affected by the surrounding medium in the underground nuclear explosion. It will influence the radiation chemical diagnosis. By Monte Carlo simulation, the fuel burnup induced by device and neutron albedo was calculated. The analysis method of albedo effect on radiation chemical diagnosis result under special environment was proposed. Neutron albedo should be considered when capture reaction burnup fraction is used, and then correct analysis can be carried out on the nuclear device.The neutron field distribution is affected by the surrounding medium in the underground nuclear explosion. It will influence the radiation chemical diagnosis. By Monte Carlo simulation, the fuel burnup induced by device and neutron albedo was calculated. The analysis method of albedo effect on radiation chemical diagnosis result under special environment was proposed. Neutron albedo should be considered when capture reaction burnup fraction is used, and then correct analysis can be carried out on the nuclear device. (authors)

  19. Towards quantum controlled initiation of explosives

    Energy Technology Data Exchange (ETDEWEB)

    Greenfield, Marge T [Los Alamos National Laboratory; Mc Grane, Shawn D [Los Alamos National Laboratory; Scharff, R Jason [Los Alamos National Laboratory; Moore, David S [Los Alamos National Laboratory

    2010-01-01

    As a first step toward understanding and controlling excited state dynamics in explosives, transient absorption spectra of Hexanitroazobenzene (HNAB) in acetone, Trinitroaniline (TNA) in acetone and Diaminoazoxyfurazan (DAAF) in dimethylsulfoxide (DMSO) were investigated in an ultrafast shaped pump/supercontinuum probe experiment for their dependence on single parameter control schemes. Two single parameter control methods, second order spectral phase (linear chirp) and the effect of pump energy on the amount of transmitted pump light were investigated. Novel transient absorption spectra were obtained for the three explosives. The spectral features found in the HNAB and TNA solutions had evidence of more complex control possibilities, while the spectral features of DAAF were dominated by intensity control.

  20. MC3D modelling of stratified explosion

    International Nuclear Information System (INIS)

    It is known that a steam explosion can occur in a stratified geometry and that the observed yields are lower than in the case of explosion in a premixture configuration. However, very few models are available to quantify the amount of melt which can be involved and the pressure peak that can be developed. In the stratified application of the MC3D code, mixing and fragmentation of the melt are explained by the growth of Kelvin Helmholtz instabilities due to the shear flow of the two phase coolant above the melt. Such a model is then used to recalculate the Frost-Ciccarelli tin-water experiment. Pressure peak, speed of propagation, bubble shape and erosion height are well reproduced as well as the influence of the inertial constraint (height of the water pool). (author)

  1. A Local Propagation for Vapor Explosions

    International Nuclear Information System (INIS)

    Explosive boiling, defined as energy transfer leading to formation of vapor rapidly enough to produce large shock waves, has been widely studied in a number of contexts. Depending upon the nature and temperatures of the liquids and mode of contacting, large-scale mixing and explosive vaporization may occur, or alternatively, only relatively non-energetic, film-type boiling may exist. The key difference is whether a mechanism is operative for increasing the liquid-liquid interfacial area in a time scale consistent with the formation of a detonation wave. Small drops of a cold volatile liquid were dropped onto a free surface of a hot, non-volatile liquid. The critical Weber number for coalescence is obtained from the envelope of the film boiling region. Markedly different behavior for the two hot liquids is observed. A 'splash' theory for local propagation of vapor explosions in spontaneously nucleating liquid-liquid systems is now formulated. After a random contact is made, explosive growth and coalescence of the vapor bubbles occurs as soon as the surrounding pressure is relieved, resulting in a high-pressure vapor layer at the liquid-liquid contact area. This amounts to an impact pressure applied to the free surface, with a resulting velocity distribution obtained from potential flow theory. The peak pressure predictions are. consistent with data for Freon-oil mixing, but further evaluation will await additional experimental data. Nevertheless, the current inference is that a UO2 -Na vapor explosion in a reactor environment cannot be visualized. In conclusion: The propagation model presented here differs in some details from that of Henry and Fauske, although both are consistent with some peak pressure data obtained by Henry, et al. Clearly, additional experimental information is needed for further evaluation of these theories. Nevertheless, it should be emphasized that even at this time a number of important observations concerning the requirements for a vapor

  2. Plasma focus experiments powered by explosive generators

    International Nuclear Information System (INIS)

    The plasma focus project began as an effort to develop an intense, pulsed, expendable neutron radiographic source. Since previous efforts to power a plasma focus with explosive generators had been successful, we proposed to couple our plate generators to a coaxial-geometry plasma focus to achieve this goal. Utilizing a small capacitor bank and a selected set of diagnostics, the explosive experiments were successfully conducted with maximum currents of 1.5 MA to 2.4 MA. A maximum neutron yield of approx. 3 x 1011 (DD) neutrons was achieved at the 2.4 MA level. Since the neutron yield did scale as a power of the maximum delivered current, and the neutron-producing source region was small, we conclude that this approach is an attractive option to achieve a neutron radiographic source. The need for a reliable open-circuiting switch at several megamperes has resulted in postponement of the project

  3. Electronic Nose for Detection of Explosives.

    Science.gov (United States)

    Oakes, Landon; Dobrokhotov, Vladimir

    2010-03-01

    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.

  4. Neutrino oscillations in magnetically driven supernova explosions

    CERN Document Server

    Kawagoe, Shio; Kotake, Kei

    2009-01-01

    We investigate neutrino oscillations from core-collapse supernovae that produce magnetohydrodynamic (MHD) explosions. By calculating numerically the flavor conversion of neutrinos in the highly non-spherical envelope, we study how the explosion anisotropy has impacts on the emergent neutrino spectra through the Mikheyev-Smirnov-Wolfenstein effect. In the case of the inverted mass hierarcy with a relatively large theta_(13), we show that survival probabilities of electron type neutrinos and antineutrinos seen from the rotational axis of the MHD supernovae (i.e., polar direction), can be significantly different from those along the equatorial direction. The event numbers of electron type antineutrinos observed from the polar direction are predicted to show steepest decrease, reflecting the passage of the magneto-driven shock to the so-called high-resonance regions. Furthermore we point out that such a shock effect, depending on the original neutrino spectra, appears also for the low-resonance regions, which lea...

  5. Lower head integrity under steam explosion loads

    International Nuclear Information System (INIS)

    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 three-dimensional mixing and explosion wave dynamics, and lower head fragility under local, dynamic loading. All of these factors are brought together in a ROAAM probabilistic framework to evaluate failure likelihood. The conclusion is that failure is 'physically unreasonable'. (orig.)

  6. Lower head integrity under steam explosion loads

    International Nuclear Information System (INIS)

    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)

  7. Explosive compaction of nanocrystalline alumina powder

    International Nuclear Information System (INIS)

    Nano ceramics have special properties: they are superhard, frictionless and have very fine pores. These special properties are shown only with grain sizes below 100 nanometers (nm). It is very difficult to retain this small grain size during conventional consolidation of powders and subsequent sinter processes. A key to solve this problem could be the explosive consolidation with shock pressures up to ∼30 GPa. Experiments with nano Al2O3 - powder which was produced by the 'exploding wire technique' with a mean crystallite size of ∼60 nm showed that almost 100 % of crystalline density is achievable by explosive consolidation. By SEM - and XRD - analysis is found that phase transitions occur and as a result of high shock wave treatment lattice distortion in the material decreases and subgrain size increases. (author)

  8. Detection of explosive events by monitoring acoustically-induced geomagnetic perturbations

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, J P; Rock, D R; Shaeffer, D L; Warshaw, S I

    1999-10-07

    The Black Thunder Coal Mine (BTCM) near Gillette, Wyoming was used as a test bed to determine the feasibility of detecting explosion-induced geomagnetic disturbances with ground-based induction magnetometers. Two magnetic observatories were fielded at distances of 50 km and 64 km geomagnetically north from the northernmost edge of BTCM. Each observatory consisted of three separate but mutually orthogonal magnetometers, Global Positioning System (GPS) timing, battery and solar power, a data acquisition and storage system, and a three-axis seismometer. Explosions with yields of 1 to 3 kT of TNT equivalent occur approximately every three weeks at BTCM. We hypothesize that explosion-induced acoustic waves propagate upward and interact collisionally with the ionosphere to produce ionospheric electron density (and concomitant current density) perturbations which act as sources for geomagnetic disturbances. These disturbances propagate through an ionospheric Alfven waveguide that we postulate to be leaky (due to the imperfectly conducting lower ionospheric boundary). Consequently, wave energy may be observed on the ground. We observed transient pulses, known as Q-bursts, with pulse widths about 0.5 s and with spectral energy dominated by the Schumann resonances. These resonances appear to be excited in the earth-ionosphere cavity by Alfven solitons that may have been generated by the explosion-induced acoustic waves reaching the ionospheric E and F regions and that subsequently propagate down through the ionosphere to the atmosphere. In addition, we observe late time (> 800 s) ultra low frequency (ULF) geomagnetic perturbations that appear to originate in the upper F region ({approximately}300 km) and appear to be caused by the explosion-induced acoustic wave interacting with that part of the ionosphere. We suggest that explosion-induced Q-bursts may be discriminated from naturally occurring Q-bursts by association of the former with the late time explosion-induced ULF

  9. Duration of nuclear explosion ground motion

    International Nuclear Information System (INIS)

    This paper evaluates the duration of strong ground shaking that results from nuclear explosions and identifies some of the problems associated with its determination. Knowledge of the duration of horizontal ground shaking is important out to epicentral distances of about 44 km and 135 km, the approximate distances at which the ground shaking level falls to 0.01 g for nuclear explosions having yields of about 100 kt and 1,000 kt, respectively. Evaluation of the strong ground motions recorded from the event STRAIT (M/sub L/ = 5.6) on a linear array of five, broad-band velocity seismographs deployed in the distance range 3.2 to 19.5 km provides information about the characteristics of the duration of ground shaking. The STRAIT data show that: (1) the definition that is used for defining duration is very important; (2) the duration of ground acceleration, as defined in terms of 90% of the integral of the squared time history, increased from about 4 to 26 sec over the approximately 20-km distance range; and (3) the duration of ground velocity and displacement were slightly greater because of the effect of the alluvium layer on the propagating surface waves. Data from other events augment the STRAIT data and show that: (1) duration of shaking is increased by frequency-dependent site effects and (2) duration of shaking, as defined by the integral of the squared time history, does not increase as rapidly with increase in yield as is indicated by other definitions of duration that are stated in terms of an amplitude threshold (e.g., bracketed duration, response envelopes). The available data suggest that the duration of ground acceleration, based on the integral definition, varies from about 4 to 40 sec for a 100-kt range explosion and from about 4 to 105 sec for a megaton range explosion in the epicentral distance range of 0 to 44 km and 0 to 135 km, respectively

  10. Explosion propagation in inert porous media.

    Science.gov (United States)

    Ciccarelli, G

    2012-02-13

    Porous media are often used in flame arresters because of the high surface area to volume ratio that is required for flame quenching. However, if the flame is not quenched, the flow obstruction within the porous media can promote explosion escalation, which is a well-known phenomenon in obstacle-laden channels. There are many parallels between explosion propagation through porous media and obstacle-laden channels. In both cases, the obstructions play a duel role. On the one hand, the obstruction enhances explosion propagation through an early shear-driven turbulence production mechanism and then later by shock-flame interactions that occur from lead shock reflections. On the other hand, the presence of an obstruction can suppress explosion propagation through momentum and heat losses, which both impede the unburned gas flow and extract energy from the expanding combustion products. In obstacle-laden channels, there are well-defined propagation regimes that are easily distinguished by abrupt changes in velocity. In porous media, the propagation regimes are not as distinguishable. In porous media the entire flamefront is affected, and the effects of heat loss, turbulence and compressibility are smoothly blended over most of the propagation velocity range. At low subsonic propagation speeds, heat loss to the porous media dominates, whereas at higher supersonic speeds turbulence and compressibility are important. This blending of the important phenomena results in no clear transition in propagation mechanism that is characterized by an abrupt change in propagation velocity. This is especially true for propagation velocities above the speed of sound where many experiments performed with fuel-air mixtures show a smooth increase in the propagation velocity with mixture reactivity up to the theoretical detonation wave velocity. PMID:22213663

  11. Antimatter induced fusion and thermonuclear explosions

    OpenAIRE

    Gsponer, Andre; Hurni, Jean-Pierre

    2005-01-01

    The feasibility of using antihydrogen for igniting inertial confinement fusion pellets or triggering large scale thermonuclear explosions is investigated. The number of antiproton annihilations required to start a thermonuclear burn wave in either DT or Li_2DT is found to be about 10^{21}/k^2, where k is the compression factor of the fuel to be ignited. In the second part, the technologies for producing antiprotons with high energy accelerator systems and the means for manipulating and storin...

  12. Microarray sensors for detecting airborne explosives

    OpenAIRE

    Caygill, J. S.

    2011-01-01

    Due to the enhanced level of national security currently required due to the possibility of terrorist attack, monitoring devices for trace levels of explosive materials are now of the upmost importance. One such method that offers a possible route towards the development of a system for the detection of such analytes is via an electrochemical regime, coupled to the use of disposable sensor technology. Within this study, the use of modified carbon screen-printed sensors for the ...

  13. Handling combinatorial explosion in software testing

    OpenAIRE

    Grindal, Mats

    2007-01-01

    In this thesis, the overall conclusion is that combination strategies, (i.e., test case selection methods that manage the combinatorial explosion of possible things to test), can improve the software testing in most organizations. The research underlying this thesis emphasizes relevance by working in close relationship with industry. Input parameter models of test objects play a crucial role for combination strategies. These models consist of parameters with corresponding parameter values and...

  14. Relative flow rates of explosive powders

    Energy Technology Data Exchange (ETDEWEB)

    Willson, V.P.

    1988-05-31

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

  15. DOE explosives safety manual. Revision 7

    Energy Technology Data Exchange (ETDEWEB)

    1994-08-01

    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.

  16. Remote detection of explosives using trained canines

    International Nuclear Information System (INIS)

    Use of dogs is a search method which combines high probability of detection, speed of search, and low cost. It was concluded that the canine could be used for explosive screening of personnel, but that it was imperative that the dog be in a position remote from employees and employee traffic. A study was made of the design of booths and air flow for this purpose. Results of tests and conclusions are given and discussed

  17. 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)

    2015-11-30

    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.

  18. Addresing State Explosion in Behavior Protocol Verification

    Czech Academy of Sciences Publication Activity Database

    Mach, M.; Plášil, František

    Michigan : ACIS, 2004 - (Hu, G.; Huang, T.; Ni, X.; Zhou, A.), s. 327-333 ISBN 0-9700776-8-8. [ACIS. International Conference on Software Engineering, Artificial Intelligence, Networking and Parallel /Distributed Computing /5./. Beijing (CN), 30.06.2004-02.07.2004] R&D Projects: GA ČR GA102/03/0672 Institutional research plan: CEZ:AV0Z1030915 Keywords : formal verification * software components * state explosion * behavior protocols * parse trees Subject RIV: JD - Computer Applications, Robotics

  19. How supernova explosions power galactic winds

    OpenAIRE

    Creasey, P.; Theuns, Tom; Bower, R. G.

    2012-01-01

    Feedback from supernovae is an essential aspect of galaxy formation. In order to improve subgrid models of feedback, we perform a series of numerical experiments to investigate how supernova explosions shape the interstellar medium (ISM) in a disc galaxy and power a galactic wind. We use the FLASH hydrodynamic code to model a simplified ISM, including gravity, hydrodynamics, radiative cooling above 104 K and star formation that reproduces the Kennicutt–Schmidt relation. By simulating a small ...

  20. Non-explosion criteria for relativistic diffusions

    CERN Document Server

    Bailleul, Ismael

    2010-01-01

    General Lorentz covariant operators, associated to so-called $\\Theta$(or $\\Xi$)-relativistic diffusions, and making sense in any Lorentz manifold, were introduced by Franchi and Le Jan in [F-LJ-1], [F-LJ-2]. Only a few examples have been studied. We provide in this work non-explosion criteria for these diffusions, which can be used in generic cases.

  1. Prediction of Overpressure from Finite Volume Explosions

    Directory of Open Access Journals (Sweden)

    K. Ramamurthi

    1995-01-01

    Full Text Available Tri-nitro toluene (TNT equivalence is not a good criterion for evaluating the practically encounted nonideal blast waves during ignition and in explosion-safety problems. A theoretical model which shows the trends related to the effects of source volume and energy time release on blast wave strength is discussed. A slower energy release and a larger source volume are shown to be necessary to reduce the blast effects.

  2. Coal self-heating and explosibility

    Energy Technology Data Exchange (ETDEWEB)

    Gouws, M.J.; Knoetze, T.P. [University of the Witwatersrand, Johannesburg (South Africa). Dept. of Mining Engineering

    1995-01-01

    The spontaneous combustion of coal and the explosion of coal dust are two phenomena that were identified by the South African mining industry as requiring investigation. Research contracts were awarded to the G.P. Badenhorst Research Facility of the CSIR and the Department of Mining Engineering of the University of Witwatersrand by the now defunct National Energy Council. Both projects entailed tests on numerous coal samples in specially designed apparatus. Since the completion of the project, attempts have been made to predict experimental results without incurring the cost of performing experiments. This paper describes predictive indices, based on routine laboratory tests, that were developed by the different research teams for their particular projects. A comparison of the results obtained by applying the spontaneous combustion liability index and the explosibility index to common coal samples indicates that, in general, propensity to spontaneous combustion and explosibility exhibit an inverse relationship. A brief overview is given of some major South African coal-mine disasters. 9 refs., 6 figs., 2 tabs.

  3. Neutrino oscillations in MHD supernova explosions

    International Nuclear Information System (INIS)

    We calculate the neutrino oscillations numerically in magnetohydrodynamic (MHD) explosion models to see how asphericity has impacts on neutrino spectra. Magneto-driven explosions are one of the most attracting scenarios for producing large scale departures from spherical symmetric geometry, that are reported by many observational data. We find that the event rates at Super-Kamiokande (SK) seen from the polar direction (e.g., the rotational axis of the supernovae) decrease when the shock wave is propagating through H-resonance. In addition, we find that L-resonance in this situation becomes non-adiabatic, and the effect of L-resonance appears in the neutrino signal, because the MHD shock can propagate to the stellar surface without shock-stall after core bounce, and the shock reaches the L-resonance at earlier stage than the conventional spherical supernova explosion models. Our results suggest that we may obtain the observational signatures of the two resonances in SK for Galactic supernova.

  4. Underground nuclear explosions at Astrakhan, USSR

    Energy Technology Data Exchange (ETDEWEB)

    Borg, I.Y.

    1982-08-13

    The three underground nuclear explosions recorded in 1980 and 1981 by Hagfors Observatory in Sweden are in the vicinity of Astrakhan on the Caspian Sea. They are believed to be associated with the development of a gas condensate field discovered in 1973. The gas producing horizons are in limestones at 4000 m depth. They are overlain by bedded, Kungarian salts. Salt domes are recognized in the area. Plans to develop the field are contained in the 11th Five Year Plan (1981-82). The USSR has solicited bids from western contractors to build gas separation and gas processing plant with an annual capacity of 6 billion m/sup 3/. Ultimate expansion plans call for three plants with the total capacity of 18 billion m/sup 3/. By analogy with similar peaceful nuclear explosions described in 1975 by the Soviets at another gas condensate field, the underground cavities are probably designed for storage of unstable, sour condensate after initial separation from the gaseous phases in the field. Assuming that the medium surrounding the explosions is salt, the volume of each cavity is on the order of 50,000 m/sup 3/.

  5. The Biggest Explosions in the Universe

    CERN Document Server

    Johnson, Jarrett L; Even, Wesley; Fryer, Chris L; Heger, Alex; Smidt, Joseph; Chen, Ke-Jung

    2013-01-01

    Supermassive primordial stars are expected to form in a small fraction of massive protogalaxies in the early universe, and are generally conceived of as the progenitors of the seeds of supermassive black holes (BHs) at high redshift. Supermassive stars with masses of ~ 55,000 M_Sun, however, have been found to explode and completely disrupt in a supernova (SN) with an energy of up to ~ 10^55 erg, instead of collapsing to a BH. Such events, roughly 10,000 times more energetic than typical SNe today, would be among the biggest explosions in the history of the universe. We carry out a simulation of such a supermassive star SN in two stages. Using the RAGE radiation hydrodynamics code we first evolve the explosion from the earliest stages, through the breakout of the shock from the surface of the star until the blast wave has propagated out to several parsecs from the explosion site, which lies deep within an atomic cooling dark matter (DM) halo at z ~ 15. Then, using the GADGET cosmological hydrodynamics code we...

  6. Ionospheric Effects of Underground Nuclear Explosions

    Science.gov (United States)

    Park, J.; von Frese, R. R.; G-Brzezinska, D. A.; Morton, Y.

    2010-12-01

    Telemetry from the Russian INTERCOSMOS 24 satellite recorded ELF and VLF electromagnetic disturbances in the outer ionosphere from an underground nuclear explosion that was detonated at Novaya Zemlya Island on 24 October 1994. The IC24 satellite observations were obtained at about 900 km altitude within a few degrees of ground zero. The disturbances were interpreted for magnetohydrodynamic excitation of the ionosphere’s E layer by the acoustic wave. Electrons are accelerated along the magnetic force lines to amplify longitudinal currents and magnetic disturbances that may be measured by magnetometers at ground-based observatories and on-board satellites. The underground nuclear test near P’unggye, North Korea on 25 May 2009 provides a further significant opportunity for studying the utility of ionospheric disturbances for characterizing ground zero. Of the seismic, infrasound, hydroacoustic, and radionuclide detection elements of the International Monitoring System (IMS) established by the Comprehensive Nuclear Test Ban Treaty Organization (CTBTO), only the first two elements detected this event. However, the event also appears to have been recorded as a direct traveling ionospheric disturbance (TID) in the slant total electron content (TEC) observations derived from a network of the Global Navigation Satellite System (GNSS) measurements. The TID was observed to distances of at least 600 km from the explosion site propagating with a speed of about 281m/s. Thus, the global distributions and temporal variations of the TEC, may provide important information to help detect and characterize clandestine underground nuclear explosions.

  7. Explosive formation of coherent particle jets

    International Nuclear Information System (INIS)

    A coherent jet of particles may be generated by accelerating a conical volume of particles by detonating a layer of explosive lining the outside of the cone. Experiments have been carried out to determine the dependence of the velocity history and coherency of the jet on the particle properties and the ratio of the masses of the particles and explosive. Steel particles form thin, coherent jets, whereas lighter glass particles lead to more diffuse jets. For steel particles, the cone angle had little effect on the coherency of the jet. The efficiency of the conversion of chemical to kinetic energy is explored by comparing the experimental jet velocity with the velocity predicted from a formulation of the Gurney method for a conical geometry. The effect of particle density and cone angle on the jet formation and development was also investigated using a multimaterial hydrocode. The simulations give insight into the extent of the deformation of the particle bed in the early stages of explosive particle dispersal.

  8. Propulsion of space ships by nuclear explosion

    Science.gov (United States)

    Linhart, J. G.; Kravárik, J.

    2005-01-01

    Recent progress in the research on deuterium-tritium (D-T) inertially confined microexplosions encourages one to reconsider the nuclear propulsion of spaceships based on the concept originally proposed in the Orion project. We discuss first the acceleration of medium-sized spaceships by D-T explosions whose output is in the range of 0.1 10 t of TNT. The launching of such a ship into an Earth orbit or beyond by a large nuclear explosion in an underground cavity is sketched out in the second section of the paper, and finally we consider a hypothetical Mars mission based on these concepts. In the conclusion it is argued that propulsion based on the Orion concept only is not the best method for interplanetary travel owing to the very large number of nuclear explosion required. A combination of a super gun and subsequent rocket propulsion using advanced chemical fuels appears to be the best solution for space flights of the near future.

  9. Computed tomography experiments of Pantex high explosives

    Science.gov (United States)

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

    1992-04-01

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

  10. Explosive Detection in Aviation Applications Using CT

    Energy Technology Data Exchange (ETDEWEB)

    Martz, H E; Crawford, C R

    2011-02-15

    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.

  11. Multi-sensor explosive detection system

    International Nuclear Information System (INIS)

    This patent describes an explosive detection system. It comprises a source of neutrons; a detector array comprising a plurality of gamma ray detectors, each of the gamma ray detectors providing a detection signal in the event a gamma ray is captured by the detector, and at least one neutron detector, the neutron detector providing a neutron detection signal in the event a neutron is captured by the neutron detector; means for irradiating an object being examined with neutrons from the neutron source and for positioning the detector array relative to the object so that gamma rays emitted from the elements within the object as a result of the neutron irradiation are detected by the gamma ray detectors of the detector array; and parallel distributed processing means responsive to the detection signals of the detector array for discriminating between objects carrying explosives and objects not carrying explosives, the parallel distributed processing means including an artificial neural system (ANS), the ANS having a parallel network of processors, each processor of the parallel network of processors, each processor of the parallel network of processors including means for receiving at least one input signal, and means for generating an output signal as a function of the at least one input signal

  12. A new type of stellar explosion

    CERN Document Server

    Perets, H B; Mazzali, P; Arnett, D; Kagan, D; Filippenko, A V; Li, W; Cenko, S B; Fox, D B; Leonard, D C; Moon, D -S; Sand, D J; Soderberg, A M; Foley, R J; Ganeshalingam, M; Anderson, J P; James, P A; Ofek, E O; Bildsten, L; Nelemans, G; Shen, K J; Weinberg, N N; Metzger, B D; Piro, A L; Quataert, E; Kiewe, M; Poznanski, D

    2009-01-01

    The explosive deaths of stars (supernovae; SNe) are generally explained by two physical processes. Young massive stars (more than eight solar masses, M_Sun) undergo gravitational core-collapse and appear as type Ib/c and II SNe. Type Ia SNe result from thermonuclear explosions of older, Chandrasekhar-mass carbon-oxygen white dwarfs (WDs). Even the most underluminous SNe Ia eject ~1 M_Sun of C/O burning products. Here we report our discovery of the faint type Ib SN 2005E in the halo of the nearby isolated galaxy, NGC 1032. The lack of any trace of recent star formation near the SN location, and the very low ejected mass we find (~0.3 M_Sun) argues strongly against a core-collapse origin of this event. Our spectroscopic observations and the derived nucleosynthetic output show that the SN ejecta is dominated by helium-burning products, indicating that SN 2005E was neither a subluminous nor a regular SNe Ia. We have therefore found a new type of stellar explosion, arising from a low-mass, old stellar system. The ...

  13. Development of steam explosion simulation code JASMINE

    International Nuclear Information System (INIS)

    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)

  14. Explosive Detection in Aviation Applications Using CT

    International Nuclear Information System (INIS)

    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.

  15. Near-Source Scattering of Explosion-Generated Rg: Insight From Difference Spectrograms of NTS Explosions

    Science.gov (United States)

    Gupta, I.; Chan, W.; Wagner, R.

    2005-12-01

    Several recent studies of the generation of low-frequency Lg from explosions indicate that the Lg wavetrain from explosions contains significant contributions from (1) the scattering of explosion-generated Rg into S and (2) direct S waves from the non-spherical spall source associated with a buried explosion. The pronounced spectral nulls observed in Lg spectra of Yucca Flats (NTS) and Semipalatinsk explosions (Patton and Taylor, 1995; Gupta et al., 1997) are related to Rg excitation caused by spall-related block motions in a conical volume over the shot point, which may be approximately represented by a compensated linear vector dipole (CLVD) source (Patton et al., 2005). Frequency-dependent excitation of Rg waves should be imprinted on all scattered P, S and Lg waves. A spectrogram may be considered as a three-dimensional matrix of numbers providing amplitude and frequency information for each point in the time series. We found difference spectrograms, derived from a normal explosion and a closely located over-buried shot recorded at the same common station, to be remarkably useful for an understanding of the origin and spectral contents of various regional phases. This technique allows isolation of source characteristics, essentially free from path and recording site effects, since the overburied shot acts as the empirical Green's function. Application of this methodology to several pairs of closely located explosions shows that the scattering of explosion-generated Rg makes significant contribution to not only Lg and its coda but also to the two other regional phases Pg (presumably by the scattering of Rg into P) and Sn. The scattered energy, identified by the presence of a spectral null at the appropriate frequency, generally appears to be more prominent in the somewhat later-arriving sections of Pg, Sn, and Lg than in the initial part. Difference spectrograms appear to provide a powerful new technique for understanding the mechanism of near-source scattering

  16. Calibrated explosive triangle for determining capacity of explosion of gas mixtures

    Institute of Scientific and Technical Information of China (English)

    Cheng Jianwei; Yang Shengqiang; Sun Qi

    2011-01-01

    Determination of the capacity for explosion of gas mixtures in a sealed area is very important for mining engineers.If this capacity is high,it would be very dangerous for rescue workers to proceed with their rescue operations.A number of methods have been developed to determine the capacity for explosion of gas mixtures in sealed areas.One of the more popular methods is the Coward explosive triangle,published by Coward.He presented a fast and easy way to determine the capacity for explosion of gas mixtures,which has proved to be a very useful tool for mining engineers and members of rescue teams.However,due to few drawbacks in this method; potential errors would be introduced when it is applied.In a brief introduction we first describe the Coward method and then,we propose and discuss new calibrated explosive triangles.We demonstrate the method in two case studies where we compare our results with those of the old model.The results indicate that the calibrated method have improved accuracy and reliability.Therefore,assessments can be made more accurately.

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

    International Nuclear Information System (INIS)

    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.

  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)

    2012-09-04

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

    Science.gov (United States)

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

    2016-08-01

    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. PMID:27586770

  20. Nucleation Characteristics in Physical Experiments/explosions

    International Nuclear Information System (INIS)

    Large-scale vapor explosion experiments have shown that intimate contact between hot and cold liquids, and a temperature upon contact that is greater than the spontaneous nucleation temperature of the system, are two necessary conditions for the onset of large scale vapor explosions. A model, based on spontaneous nucleation of the homogeneous type, has been proposed to describe the relevant processes and the resulting energetics for explosive boiling systems. The model considers that spontaneous nucleation cannot occur either during the relief time for constant volume heating or until the thermal boundary layer is sufficiently thick to support a vapor cavity of the critical size. After nucleation, bubble growth does not occur until an acoustic wave establishes a pressure gradient in the cold liquid. These considerations lead to the prediction that, for a given temperature, drops greater than a critical size will remain in film boiling due to coalescence of vapor nuclei and drops smaller than this value will wet and be captured by the hot liquid surface. These results are compared to small drop data for well-wetted systems and excellent agreement is obtained between the observed behavior and the model predictions. In conclusion: A model, based on spontaneous nucleation, has been proposed to describe vaporization potential and behavior upon contact in a liquid/liquid system. This behavior is determined by the size of the liquid mass, single-phase pressurization and acoustic relief, nucleation frequency due to random density fluctuations, the initiation of unstable growth and acoustic relief, and the development of the thermal boundary layer in the cold liquid. The proposed model predicts that the stability of a given size drop upon intimate contact with another liquid is extremely dependent upon the interface temperature. For low interface temperatures, large masses will be captured by the hot liquid and the resulting vaporization rates will be extremely low because