30 CFR 27.33 - Test to determine explosion-proof construction.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Test to determine explosion-proof construction. 27.33 Section 27.33 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS Test Requirements § 27.33...

30 CFR 27.33 - Test to determine explosion-proof construction.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Test to determine explosion-proof construction. 27.33 Section 27.33 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS Test Requirements § 27.33...

27 CFR 555.103 - Transactions among licensees/permittees and transactions among licensees and holders of user...

Code of Federal Regulations, 2013 CFR

2013-04-01

... explosive materials, e.g., resale, mining, quarrying, agriculture, construction, sport rocketry, road... the explosive materials, e.g., resale, mining, quarrying, agriculture, construction, sport rocketry... Management and Budget under control number 1140-0079) [ATF No. 1, 68 FR 13787, Mar. 20, 2003, as amended by...

FY97 Environmental Technology Division Annual Report.

DTIC Science & Technology

1997-12-01

Stripping System at Letterkenny Army Depot ......... 83 Peroxone Treatment of Explosives-Contaminated Groundwater ........ 84 Phytoremediation in Hawaii...86 Phytoremediation of Explosives in Groundwater Using Constructed Wetlands .................................. 88... Phytoremediation of Lead in Soil ............................... 91 Plant Uptake and Weathering Studies on Composted Explosives-Contaminated Soil

An AIEE fluorescent supramolecular cross-linked polymer network based on pillar[5]arene host-guest recognition: construction and application in explosive detection.

PubMed

Shao, Li; Sun, Jifu; Hua, Bin; Huang, Feihe

2018-05-08

Here a novel fluorescent supramolecular cross-linked polymer network with aggregation induced enhanced emission (AIEE) properties was constructed via pillar[5]arene-based host-guest recognition. Furthermore, the supramolecular polymer network can be used for explosive detection in both solution and thin films.

Seismic explosive charge loader and anchor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mcreynolds, O.B.

1981-07-14

An improved seismic explosive charge loader and anchor for loading and anchoring explosives in cylindrical containers in bore holes is disclosed, which includes a snap in spring band shaped anchor which effectively anchors the loader in the well bore against upward movement, one aspect of the invention includes a snap lock threaded connection for securing an explosive container having interrupted threads to the loader and anchor, and the loader and anchor is constructed and arranged to maintain a detonator in place in the explosive container thereby assuring detonation of the explosive.

A deep towed explosive source for seismic experiments on the ocean floor

NASA Astrophysics Data System (ADS)

Koelsch, Donald E.; Witzell, Warren E.; Broda, James E.; Wooding, Frank B.; Purdy, G. M.

1986-12-01

A new seismic source for carrying out high resolution measurements of deep ocean crustal structure has been constructed and successfully used in a number of ocean bottom refraction experiments on the Mid Atlantic Ridge near 23° N. The source is towed within 100 m of the ocean floor on a conventional 0.68″ coaxial cable and is capable of firing, upon command from the research vessel, up to 48 individual 2.3 kg explosive charges. The explosive used was commercially available Penta-Erythritol-Tetra Nitrate (PETN) that was activated by 14.9 gm m-1 Primacord and DuPont E-97 electrical detonators. For safety reasons each detonator was fitted with a pressure switch that maintained a short until the source was at depth in excess of approximately 300 m. In addition, a mechanical protector isolated the detonator from the main charge and was only removed by the physical release of the explosive from the source package. These and other safety precautions resulted in several misfires but three experiments were successfully completed during the summer of 1985 at source depths of 3000 4000 m.

Demonstration plan for phytoremediation of explosive-contaminated groundwater in constructed wetlands at Milan Army Ammunition Plant Milan Tennessee. Volume 2. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Behrends, L.; Sikora, F.; Kelly, D.

1996-01-01

To demonstrate at Milan AAP in April 1996 through July 1997, the technical and economic feasibility of using phytoremediation in an artificial constructed wetlands for treatment of explosives-contaminated groundwater. Validated data on cost and effectiveness of this demonstration will be used to transfer this technology to the user community.

Demonstration plan for phytoremediation of explosive-contaminated groundwater in constructed wetlands at Milan Army Ammunition Plant Milan Tennessee. Volume 1. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Behrends, L.; Sikora, F.; Kelly, D.

1996-01-01

To demonstrate at Milan AAP in April 1996 through July 1997, the technical and economic feasibility of using phytoremediation in an artificial, constructed wetlands for treatment of explosives-contaminated groundwater. Validated data on cost and effectiveness of this demonstration will be used to transfer this technology to the user community.

Savannah River Plant engineering, design, and construction history of ``S`` projects and other work, January 1961--December 1964. Volume 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1970-03-01

The work described in this volume of ``S`` Projects History is an extension of the type of work described in Volume I. E.I. du Pont de flemours & Company had entered into Contract AT (07-2)-l with the United States Atomic Energy Commission to develop, design, construct, install, and operate facilities to produce heavy water, fissionable materials, and related products. Under this contract,, Du Pont constructed and operated the Savannah River Plant. The engineering, design, and construction for most of the larger ``S`` projects was performed by the Engineering DeDartment. For some of the large and many of the smaller projectsmore » the Engineering Department was responsible only for the construction because the Atomic Energy Division (AED) of the Explosives Department handled the other phases. The Engineering Department Costruction Division also performed the physical work for many of the plant work orders. This volume includes a general description of the Du Pont Engineering Department activities pertaining to the engineering, design, and construction of the ``S`` projects at the Savannah River Plant; brief summaries of the projects and principal work requests; and supplementary informaticn on a few subjects in Volume I for which final data was not available at the closing date. Projects and other plant engineering work which were handled entirely by the Explosives Department -- AED are not included in this history.« less

Dye@bio-MOF-1 Composite as a Dual-Emitting Platform for Enhanced Detection of a Wide Range of Explosive Molecules.

PubMed

Wang, Chen; Tian, Li; Zhu, Wei; Wang, Shiqiang; Wang, Peng; Liang, Yun; Zhang, Wanlin; Zhao, Hongwei; Li, Guangtao

2017-06-14

By incorporating a cationic dye within a metal-organic framework (MOF) through an ion-exchange process, a responsive dye@bio-MOF-1 composite has been synthesized, serving as a dual-emitting platform for enhanced detection of different kinds of nitro-explosives, especially nitroalkanes, nitramines, and nitrate esters. The dye@bio-MOF-1 composite was constructed with free amines on their well-defined cavities, which is essential for the capture of explosives into their confined nanospace. It was observed that the encapsulation of explosives into the constructed dye@bio-MOF-1 composite could dramatically alter the luminescent properties of the dyes as well as the MOF skeletons owing to the size exclusivity and confinement-induced effect. For nitroaromatics, the dye@bio-MOF-1 composite exhibits turn-off responses via fluorescence quenching. Unexpectedly, the composite shows unique turn-on responses for aliphatic nitro-organics via confinement-induced enhancement, demonstrating enhanced ability to detecting different kinds of explosives selectively in aqueous solution. Furthermore, the dye@bio-MOF-1 film was facilely fabricated, making the chemical sensing more convenient and easier to realize the discrimination of the targeted explosives. The dual tunable responses indicate that dye@bio-MOF-1 composites are favorable materials for molecular sensing. On the basis of the host-guest properties of the constructed dye@bio-MOF-1 composite, our work can be further extended to sensing specific analytes with remarkable turn-on sensing properties, in particular those difficult to recognize with conventional methods.

Automated detection and cataloging of global explosive volcanism using the International Monitoring System infrasound network

NASA Astrophysics Data System (ADS)

Matoza, Robin S.; Green, David N.; Le Pichon, Alexis; Shearer, Peter M.; Fee, David; Mialle, Pierrick; Ceranna, Lars

2017-04-01

We experiment with a new method to search systematically through multiyear data from the International Monitoring System (IMS) infrasound network to identify explosive volcanic eruption signals originating anywhere on Earth. Detecting, quantifying, and cataloging the global occurrence of explosive volcanism helps toward several goals in Earth sciences and has direct applications in volcanic hazard mitigation. We combine infrasound signal association across multiple stations with source location using a brute-force, grid-search, cross-bearings approach. The algorithm corrects for a background prior rate of coherent unwanted infrasound signals (clutter) in a global grid, without needing to screen array processing detection lists from individual stations prior to association. We develop the algorithm using case studies of explosive eruptions: 2008 Kasatochi, Alaska; 2009 Sarychev Peak, Kurile Islands; and 2010 Eyjafjallajökull, Iceland. We apply the method to global IMS infrasound data from 2005-2010 to construct a preliminary acoustic catalog that emphasizes sustained explosive volcanic activity (long-duration signals or sequences of impulsive transients lasting hours to days). This work represents a step toward the goal of integrating IMS infrasound data products into global volcanic eruption early warning and notification systems. Additionally, a better understanding of volcanic signal detection and location with the IMS helps improve operational event detection, discrimination, and association capabilities.

Acoustic and tephra records of explosive eruptions at West Mata submarine volcano, NE Lau Basin

NASA Astrophysics Data System (ADS)

Dziak, R. P.; Bohnenstiehl, D. R.; Baker, E. T.; Matsumoto, H.; Caplan-Auerbach, J.; Mack, C. J.; Embley, R. W.; Merle, S. G.; Walker, S. L.; Lau, T. A.

2013-12-01

West Mata is a 1200 m deep submarine volcano where explosive boninite eruptions were directly observed in May 2009. Here we present long-term acoustic and tephra records of West Mata explosion activity from three deployments of hydrophone and particle sensor moorings beginning on 8 January 2009. These records provide insights into the character of explosive magma degassing occurring at the volcano's summit vent until the decline and eventual cessation of the eruption during late 2010 and early 2011. The detailed acoustic records show three types of volcanic signals, 1) discrete explosions, 2) diffuse explosions, and 3) volcanic tremor. Discrete explosions are short duration, high amplitude broad-band signals caused by rapid gas bubble release. Diffuse signals are likely a result of 'trap-door' explosions where a quench cap of cooled lava forms over the magmatic vent but gas pressure builds underneath the cap. This pressure eventually causes the cap to breach and gas is explosively released until pressure reduces and the cap once again forms. Volcanic tremor is typified by narrow-band, long-duration signals with overtones, as well as narrow-band tones that vary frequency over time between 60-100 Hz. The harmonic tremor is thought to be caused by modulation of rapid, short duration gas explosion pulses and not a magma resonance phenomenon. The variable frequency tones may be caused by focused degassing or hydrothermal fluid flow from a narrow volcanic vent or conduit. High frequency (>30 Hz) tremor-like bands of energy are a result of interference caused by multipath wide-band signals, including sea-surface reflected acoustic phases, that arrive at the hydrophone with small time delays. Acoustic data suggest that eruption velocities for a single explosion range from 4-50 m s-1, although synchronous arrival of explosion signals has complicated our efforts to estimate long-term gas flux. Single explosions exhibit ~4-40 m3 s-1 of total volume flux (gas and rock) but with durations of only 20-30 ms. Interestingly, explosion activity increased at West Mata for several months, observed at more distant hydrophone stations, following the September 2009 8.1 Mw Samoan earthquake. The tephra and hydrophone data were only synchronously recorded from January to May 2010, but these data indicate a repeated record of summit explosions followed by down flank debris flows, an important process in the construction of the volcanic edifice. Bathymetric differencing between 2010 and 2011 shows two large negative anomalies at the summit and a broad positive anomaly on the east flank, interpreted as a major slump that removed part of the summit during the final magma withdrawal related to formation of the summit pit crater.

Eruption History of Cone D: Implications for Current and Future Activity at Okmok Caldera

NASA Astrophysics Data System (ADS)

Beget, J.; Almberg, L.; Faust-Larsen, J.; Neal, C.

2008-12-01

Cone B at Okmok Caldera erupted in 1817, and since then activity has beeen centered in and around Cone A in the SW part of Okmok Caldera. However, prior to 1817 at least a half dozen other eruptive centers were active at various times within the caldera. Cone D was active between ca. 2000-1500 yr BP., and underwent at least two separate intervals characterized by violent hydromagmatic explosions and surge production followed by the construction of extensive lava deltas in a 150-m-deep intra-caldera lake. Reconstructions of cone morphology indicate the hydromagmatic explosions occurred when lake levels were shallow or when the eruptive cones had grown to reach the surface of the intra-caldera lake. The effusion rate over this interval averaged several million cubic meters of lava per year, implying even higher outputs during the actual eruptive episodes. At least two dozen tephra deposits on the volcano flanks date to this interval, and record frequent explosive eruptions. The pyroclastic flows and surges from Cone D and nearby cones extend as far as 14 kilometers from the caldera rim, where dozens of such deposits are preserved in a section as much as 6 m thick at a distance of 8 km beyond the rim. A hydromagmatic explosive eruption at ca. 1500 yr BP generated very large floods and resulted in the draining of the caldera lake. The 2008 hydromagmatic explosive eruptions in the Cone D area caused by interactions with lake water resulted in the generation of surges, floods and lahars that are smaller but quite similar in style to the prehistoric eruptions at Cone E ca. 2000-1500 yr BP. The style and magnitude of future eruptions at vents around Cone D will depend strongly on the evolution of the intra-caldera lake system.

The eruptive chronology of the Ampato-Sabancaya volcanic complex (Southern Peru)

NASA Astrophysics Data System (ADS)

Samaniego, Pablo; Rivera, Marco; Mariño, Jersy; Guillou, Hervé; Liorzou, Céline; Zerathe, Swann; Delgado, Rosmery; Valderrama, Patricio; Scao, Vincent

2016-09-01

We have reconstructed the eruptive chronology of the Ampato-Sabancaya volcanic complex (Southern Peru) on the basis of extensive fieldwork, and a large dataset of geochronological (40K-40Ar, 14C and 3He) and geochemical (major and trace element) data. This volcanic complex is composed of two successive edifices that have experienced discontinuous volcanic activity from Middle Pleistocene to Holocene times. The Ampato compound volcano consists of a basal edifice constructed over at least two cone-building stages dated at 450-400 ka and 230-200 ka. After a period of quiescence, the Ampato Upper edifice was constructed firstly during an effusive stage (80-70 ka), and then by the formation of three successive peaks: the Northern, Southern (40-20 ka) and Central cones (20-10 ka). The Southern peak, which is the biggest, experienced large explosive phases, resulting in deposits such as the Corinta plinian fallout. During the Holocene, eruptive activity migrated to the NE and constructed the mostly effusive Sabancaya edifice. This cone comprised many andesitic and dacitic blocky lava flows and a young terminal cone, mostly composed of pyroclastic material. Most samples from the Ampato-Sabancaya define a broad high-K magmatic trend composed of andesites and dacites with a mineral assemblage of plagioclase, amphibole, biotite, ortho- and clino-pyroxene, and Fe-Ti oxides. A secondary trend also exists, corresponding to rare dacitic explosive eruptions (i.e. Corinta fallout and flow deposits). Both magmatic trends are derived by fractional crystallisation involving an amphibole-rich cumulate with variable amounts of upper crustal assimilation. A marked change in the overall eruptive rate has been identified between Ampato ( 0.1 km3/ka) and Sabancaya (0.6-1.7 km3/ka). This abrupt change demonstrates that eruptive rates have not been homogeneous throughout the volcano's history. Based on tephrochronologic studies, the Late Holocene Sabancaya activity is characterised by strong vulcanian events, although its erupted volume remained low and only produced a local impact through ash fallout. We have identified at least 6 eruptions during the last 4-5 ka, including the historical AD 1750-1784 and 1987-1998 events. On the basis of this recurrent low-to-moderate explosive activity, Sabancaya must be considered active and a potentially threatening volcano.

An Advanced ESTCP PELAN System for Surface and Near-surface UXO Discrimination

DTIC Science & Technology

2009-03-01

system was designed and assembled at SAIC. Test slugs representing 30mm to 105mm shells were constructed and filled with inert materials and explosives...results and system design, ESTCP decided to discontinue the effort before the prototype was constructed and demonstrated. iii TABLE OF CONTENTS...RDX and non-explosive plasticizers ) cps counts per second CW Chemical Warfare agent d-T deuterium-tritium DoD Department of Defense DOE

Sensitivity to friction for primary explosives.

PubMed

Matyáš, Robert; Šelešovský, Jakub; Musil, Tomáš

2012-04-30

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

Energetic Trend in Explosive Activity of Stromboli

NASA Astrophysics Data System (ADS)

Coltelli, M.; Cristaldi, A.; Mangiagli, S.; Nunnari, G.; Pecora, E.

2003-12-01

The typical activity of Stromboli consists of intermittent mild explosions lasting a few seconds, which take place at different vents and at variable intervals, the most common time interval being 10-20 minutes. However, the routine activity can be interrupted by more violent, paroxysmal explosions, that eject m-sized scoriaceous bombs and lava blocks to a distance of several hundreds of meters from the craters, endangering the numerous tourists that watch the spectacular activity from the volcano's summit located about two hundreds meters from the active vents. On average, 1-2 paroxysmal explosions occurred per year over the past century, but this statistic may be underestimated in absence of continuous monitoring. For this reason from summer 1996 a remote surveillance camera works on Stromboli recording continuously the volcanic activity. It is located on Pizzo Sopra la Fossa, 100 metres above the crater terrace where are the active vents. Using image analysis we seeks to identify any change of the explosive activity trend that could precede a particular eruptive event, like paroxysmal explosions, fire fountains, lava flows. The analysis include the counting of the explosions occurred at the different craters and the parameterization in classes of intensity for each explosion on the base of tephra dispersion and kinetics energy. Associating at each class a corresponding Index of energy in order to compute an heuristic value of the Average Daily Energy Released (ADER) of the explosive activity at Stromboli and plotting this value for each crater versus time, the diagram shows a cyclic behavior with max and min of explosive activity ranging from a few days to a month. Often the craters show opposite trends so when the activity decreases in a crater, increases in the other. Before every paroxysmal explosions recorded, the crater that produced the event decreased and then stopped its activity from a few days to weeks before. The other crater tried to compensate increasing its activity and when it declined the paroxysmal explosion occurred suddenly at the former site. From September 2001 an on-line image analyzer called VAMOS (Volcanic Activity MOnitoring System) operates detection and classification of explosive events in real-time. The system has automatically recorded and analyzed the change in the energetic trend that preceded the 20 October 2001 paroxysmal explosion that killed a woman and the strong explosive activity that preceded the onset of 28 December 2002 lava flow eruption.

Hazard maps of Colima volcano, Mexico

NASA Astrophysics Data System (ADS)

Suarez-Plascencia, C.; Nunez-Cornu, F. J.; Escudero Ayala, C. R.

2011-12-01

Colima volcano, also known as Volcan de Fuego (19° 30.696 N, 103° 37.026 W), is located on the border between the states of Jalisco and Colima and is the most active volcano in Mexico. Began its current eruptive process in February 1991, in February 10, 1999 the biggest explosion since 1913 occurred at the summit dome. The activity during the 2001-2005 period was the most intense, but did not exceed VEI 3. The activity resulted in the formation of domes and their destruction after explosive events. The explosions originated eruptive columns, reaching attitudes between 4,500 and 9,000 m.a.s.l., further pyroclastic flows reaching distances up to 3.5 km from the crater. During the explosive events ash emissions were generated in all directions reaching distances up to 100 km, slightly affected nearby villages as Tuxpan, Tonila, Zapotlán, Cuauhtemoc, Comala, Zapotitlan de Vadillo and Toliman. During the 2005 this volcano has had an intense effusive-explosive activity, similar to the one that took place during the period of 1890 through 1900. Intense pre-plinian eruption in January 20, 1913, generated little economic losses in the lower parts of the volcano due to low population density and low socio-economic activities at the time. Shows the updating of the volcanic hazard maps published in 2001, where we identify whit SPOT satellite imagery and Google Earth, change in the land use on the slope of volcano, the expansion of the agricultural frontier on the east and southeast sides of the Colima volcano, the population inhabiting the area is approximately 517,000 people, and growing at an annual rate of 4.77%, also the region that has shown an increased in the vulnerability for the development of economic activities, supported by the construction of highways, natural gas pipelines and electrical infrastructure that connect to the Port of Manzanillo to Guadalajara city. The update the hazard maps are: a) Exclusion areas and moderate hazard for explosive events (rockfall) and pyroclastic flows, b) Hazard map of lahars and debris flow, and c) Hazard map of ash-fall. The cartographic and database information obtained will be the basis for updating the Operational Plan of the Colima Volcano by the State Civil & Fire Protection Unit of Jalisco, Mexico, and the urban development plans of surrounding municipalities, in order to reduce their vulnerability to the hazards of the volcanic activity.

30 CFR 18.42 - Explosion-proof distribution boxes.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Explosion-proof distribution boxes. 18.42 Section 18.42 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction...

Air Force construction automation/robotics

NASA Technical Reports Server (NTRS)

Nease, A. D.; Alexander, E. F.

1993-01-01

The Air Force has several missions which generate unique requirements that are being met through the development of construction robotic technology. One especially important mission will be the conduct of Department of Defense (DOD) space activities. Space operations and other missions place construction/repair equipment operators in dangerous environments and potentially harmful situations. Additionally, force reductions require that human resources be leveraged to the maximum extent possible, and more stringent construction repair requirements push for increased automation. To solve these problems, the U.S. Air Force is undertaking a research and development effort at Tyndall AFB, FL, to develop robotic construction/repair equipment. This development effort involves the following technologies: teleoperation, telerobotics, construction operations (excavation, grading, leveling, tool change), robotic vehicle communications, vehicle navigation, mission/vehicle task control architecture, and associated computing environment. The ultimate goal is the fielding of a robotic repair capability operating at the level of supervised autonomy. This paper will discuss current and planned efforts in space construction/repair, explosive ordnance disposal, hazardous waste cleanup, and fire fighting.

Metal-Free Poly-Cycloaddition of Activated Azide and Alkynes toward Multifunctional Polytriazoles: Aggregation-Induced Emission, Explosive Detection, Fluorescent Patterning, and Light Refraction.

PubMed

Wu, Yongwei; He, Benzhao; Quan, Changyun; Zheng, Chao; Deng, Haiqin; Hu, Rongrong; Zhao, Zujin; Huang, Fei; Qin, Anjun; Tang, Ben Zhong

2017-09-01

The metal-free click polymerization (MFCP) of activated alkynes and azides or activated azide and alkynes have been developed into powerful techniques for the construction of polytriazoles without the obsession of metallic catalyst residues problem. However, the MFCP of activated azides and alkynes is rarely applied in preparation of functional polytriazoles. In this paper, soluble multifunctional polytriazoles (PIa and PIb) with high weight-average molecular weights (M w up to 32 000) are prepared via the developed metal-free poly-cycloaddition of activated azide and alkynes in high yields (up to 90%). The resultant PIa and PIb are thermally stable, and show aggregation-induced emission characteristics, enabling their aggregates to detect explosives with superamplification effect. Moreover, thanks to their containing aromatic rings and polar moieties, PIa and PIb exhibit high refractive indices. In addition, they can also be cross-linked upon UV irradiation to generate 2D fluorescent patterning due to their remaining azide groups and containing ester groups. Thus, these multifunctional polytriazoles are potentially applicable in the optoelectronic and sensing fields. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evaluation of Various Organic Fertilizer Substrates and Hydraulic Retention Times for Enhancing Anaerobic Degradation of Explosives-Contaminated Groundwater While Using Constructed Wetlands at the Milan Army Ammunition Plant, Milan, Tennessee.

DTIC Science & Technology

1998-05-01

CODES FIELD GROUP SUB-GROUP 18. SUBJECT TERMS (Continue on reverse if necessary and identify by block number) Phytoremediation of Explosives... phytoremediating explosives-contaminated groundwater. A typical gravel-based wetland consists of an anaerobic cell for removing the bulk of the explosive...11 4-1 4-1 4-3 Phytoremediation Study Milan AAP SECTION TABLE OF CONTENTS (Continued) TITLE PAGE 4.0 4.3 4.4 4.5 5.0 6.0 RESULTS AND

On-line image analysis of the stromboli volcanic activity recorded by the surveillance camera helps the forecasting of the major eruptive events.

NASA Astrophysics Data System (ADS)

Cristaldi, A.; Coltelli, M.; Mangiagli, S.; Pecora, E.

2003-04-01

The typical activity of Stromboli consists of intermittent mild explosions lasting a few seconds, which take place at different vents and at variable intervals, the most common time interval being 10-20 minutes. However, the routine activity can be interrupted by more violent, paroxysmal explosions, that eject m-sized scoriaceous bombs and lava blocks to a distance of several hundreds of meters from the craters, endangering the numerous tourists that watch the spectacular activity from the volcano's summit located about two hundreds meters from the active vents. On average, 1-2 paroxysmal explosions occurred per year over the past century, but this statistic may be underestimated in absence of continuous monitoring. For this reason from summer 1996 a remote surveillance camera works on Stromboli recording continuously the volcanic activity. It is located on Pizzo Sopra la Fossa, 100 metres above the crater terrace where are the active vents. Using image analysis we seeks to identify any change of the explosive activity trend that could precede a particular eruptive event, like paroxysmal explosions, fire fountains, lava flows. From the day of the camera installation up to present 12 paroxysmal events and lava flows occurred. The analysis include the counting of the explosions occurred at the different craters and the parameterization in classes of intensity for each explosion on the base of tephra dispersion and kinetics energy. The plot of dissipated energy by each crater versus time shows a cyclic behavior with max and min of explosive activity ranging from a few days to a month. Often the craters show opposite trends so when the activity decreases in a crater, increases in the other. Before every paroxysmal explosions recorded, the crater that produced the event decreased and then stopped its activity from a few days to weeks before. The other crater tried to compensate increasing its activity and when it declined the paroxysmal explosion occurred suddenly at the former site. From September 2001 an on-line image analyzer called VAMOS (Volcanic Activity MOnitoring System) operates detection and classification of explosive events in quasi real-time. The system has automatically recorded and analyzed the change in the energetic trend that preceded the 20 October 2001 paroxysmal explosion that killed a woman and the strong explosive activity that preceded the onset of 28 December 2002 lava flow eruption.

Research on the analytical method about influence of gas leakage and explosion on subway

NASA Astrophysics Data System (ADS)

Ji, Wendong; Yang, Ligong; Chen, Lin

2018-05-01

With the construction and development of city subway, the cross impact of underground rail transit and gas pipe network is becoming more and more serious, but there is no analytical method for the impact of gas explosions on the subway. According to this paper, the gas leakage is equivalent to the TNT explosion equivalent, based on which, the calculation of the explosive impact load is carried out. On the basis of the concrete manifestation of gas explosion, it is more convenient to carry out the subsequent calculation by equivalently treating the explosive impact load as a uniform load within a certain range. The overlying soil of the subway station has played a protective role for the subway, making the displacement of the subway structure in the explosion process significantly reduced. The analysis on the actual case shows that this method can be successfully applied to the quantitative analysis of such accidents.

30 CFR 18.43 - Explosion-proof splice boxes.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Explosion-proof splice boxes. 18.43 Section 18.43 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and...

Seismic and source characteristics of large chemical explosions. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adushkin, V.V.; Kostuchenko, V.N.; Pernik, L.M.

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

76 FR 32867 - Hazardous Materials: Requirements for Storage of Explosives During Transportation

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-07

... from release into the environment. This final rule does not prohibit or promote the development of safe... Association Standard (NFPA) 498--Standard for Safe Havens and Interchange Lots for Vehicles Transporting Explosives (2010 Edition) for the construction and maintenance of safe havens used for unattended storage of...

Full-Scale Incineration System Demonstration Verification Test Burns at the Naval Battalion Construction Center, Gulfport, Mississippi. Volume 3. Treatability Tests. Part 2

DTIC Science & Technology

1991-07-01

1525 C1:y: daho Falls State: r Zip: 83413 Telephoue Hunber: (2 16) 65-1763 4. Facilities Location: Number & Steet: Naval Construction Bat.tallcn...ed into the POTW: (a) Pollutants which create a fire or explosion hazard in the POTW; (b) Pollutants which will cause corrosive structural damage to...Haylon Located in the laboratory (1) 15-1b C02 Located in the trailer 482 / 4.3.8 Maximum Hypothetical Accident ( Explosion ) The maximum hypothetical

FAA bulk technology overview for explosives detection

NASA Astrophysics Data System (ADS)

Novakoff, Alan K.

1993-04-01

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

Microbial bioreporters of trace explosives.

PubMed

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

2017-06-01

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

78 FR 18619 - Extension of Agency Information Collection Activity Under OMB Review: National Explosives...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-27

... DEPARTMENT OF HOMELAND SECURITY Transportation Security Administration Extension of Agency Information Collection Activity Under OMB Review: National Explosives Detection Canine Team Program (NEDCTP... Explosives Detection Canine Team Program (NEDCTP) canine handlers. Abstract: The FAMS/CTES Explosives...

Explosive activity associated with the growth of volcanic domes

USGS Publications Warehouse

Newhall, C.G.; Melson, W.G.

1983-01-01

Domes offer unique opportunities to measure or infer the characteristics of magmas that, at domes and elsewhere, control explosive activity. A review of explosive activity associated with historical dome growth shows that: 1. (1) explosive activity has occurred in close association with nearly all historical dome growth; 2. (2) whole-rock SiO2 content, a crude but widely reported indicator of magma viscosity, shows no systematic relationship to the timing and character of explosions; 3. (3) the average rate of dome growth, a crude indicator of the rate of supply of magma and volatiles to the near-surface enviornment, shows no systematic relationship to the timing or character of explosions; and 4. (4) new studies at Arenal and Mount St. Helens suggest that water content is the dominant control on explosions from water-rich magmas, whereas the crystal content and composition of the interstitial melt (and hence magma viscosity) are equally or more important controls on explosions from water-poor magmas. New efforts should be made to improve current, rather limited techniques for monitoring pre-eruption volatile content and magma viscosity, and thus the explosive potential of magmas. ?? 1983.

Miniature plasma accelerating detonator and method of detonating insensitive materials

DOEpatents

Bickes, R.W. Jr.; Kopczewski, M.R.; Schwarz, A.C.

1985-01-04

The invention is a detonator for use with high explosives. The detonator comprises a pair of parallel rail electrodes connected to a power supply. By shorting the electrodes at one end, a plasma is generated and accelerated toward the other end to impact against explosives. A projectile can be arranged between the rails to be accelerated by the plasma. An alternative arrangement is to a coaxial electrode construction. The invention also relates to a method of detonating explosives. 3 figs.

Miniature plasma accelerating detonator and method of detonating insensitive materials

DOEpatents

Bickes, Jr., Robert W.; Kopczewski, Michael R.; Schwarz, Alfred C.

1986-01-01

The invention is a detonator for use with high explosives. The detonator comprises a pair of parallel rail electrodes connected to a power supply. By shorting the electrodes at one end, a plasma is generated and accelerated toward the other end to impact against explosives. A projectile can be arranged between the rails to be accelerated by the plasma. An alternative arrangement is to a coaxial electrode construction. The invention also relates to a method of detonating explosives.

User’s Guide and History of ANFO (Ammonium Nitrate/Fuel Oil) as a Nuclear Weapons Effect Simulation Explosive

DTIC Science & Technology

1983-03-31

SHOCK SIMULATION 1659 - Amonium nitrate first prepared by Glauber 1867 - Swedish patent granted to Ohlsson and Norrbein for use of ammonium nitrate ...neceessay aqd identify by block number) Ammonium Nitrate -Fuel Oil Aiiblast - . ANFO . Craters High Explosives Explosive Charge Construction * Nuclear...utilizatilon of ANFO for future W FJOAMw. 1473- EDIT00 or INOW ,Sois 0"LTZ"" DO t 473 UNCLASSIFIED SECUM"TY CLASSIFfCATIOl# OF THIS PAGEI(Whonf D Ia LI L

Video monitoring of the persistent strombolian activity of Stromboli volcano represents a window on its plumbing system and an opportunity for understanding the eruptive processes

NASA Astrophysics Data System (ADS)

Coltelli, Mauro; Biale, Emilio; Ciancitto, Francesco; Pecora, Emilio; Prestifilippo, Michele

2014-05-01

Since 1994 a video-surveillance camera located on a peak just above the active volcanic vents of Stromboli island records the explosive activity of one of the few volcanoes on the world performing a persistent eruptive activity. From 2003, after one of the larger lava flow eruption of the last century, the video-surveillance system was enhanced with more stations having both thermal and visual cameras. The video-surveillance helps volcanologists to characterize the mild explosive activity of Stromboli named Strombolian and to distinguish between the frequent "ordinary" Strombolian explosions and the occasional "extraordinary" strong Strombolian explosions that periodically occur. A new class of extraordinary explosions was discovered filling the gap between the ordinary activity and the strong explosions named major explosions when the tephra fallout covers large areas on the volcano summit and paroxysmal ones when the bombs fall down to the inhabited area along the coast of the island. In order to quantify the trend of the ordinary Strombolian explosions and to understand the occurring of the extraordinary strong Strombolian explosions a computer assisted image analysis was developed to process the huge amount of thermal and visual images recorded in several years. The results of this complex analysis allow us to clarify the processes occurring in the upper plumbing system where the pockets/trains of bubbles coalesce and move into the active vent conduits producing the ordinary Strombolian activity, and to infer the process into the deeper part of the plumbing system where new magma supply and its evolution lead to the formation of the extraordinary strong Strombolian explosions.

Genetically engineered microorganisms for the detection of explosives’ residues

PubMed Central

Shemer, Benjamin; Palevsky, Noa; Yagur-Kroll, Sharon; Belkin, Shimshon

2015-01-01

The manufacture and use of explosives throughout the past century has resulted in the extensive pollution of soils and groundwater, and the widespread interment of landmines imposes a major humanitarian risk and prevents civil development of large areas. As most current landmine detection technologies require actual presence at the surveyed areas, thus posing a significant risk to personnel, diverse research efforts are aimed at the development of remote detection solutions. One possible means proposed to fulfill this objective is the use of microbial bioreporters: genetically engineered microorganisms “tailored” to generate an optical signal in the presence of explosives’ vapors. The use of such sensor bacteria will allow to pinpoint the locations of explosive devices in a minefield. While no study has yet resulted in a commercially operational system, significant progress has been made in the design and construction of explosives-sensing bacterial strains. In this article we review the attempts to construct microbial bioreporters for the detection of explosives, and analyze the steps that need to be undertaken for this strategy to be applicable for landmine detection. PMID:26579085

Improvised Explosive Devices: Unclear Whether Culvert Denial Systems to Protect Troops are Functioning or Were Ever Installed

DTIC Science & Technology

2013-07-23

Regional Command-South. At least 4 of the contracts awarded by RCC-Kandahar were blanket purchase agreements ( BPA ) with multiple task orders against them...for the construction of culvert denial systems. Of the BPAs that we reviewed, both W91B4L-11-A-0031 (82 task orders) and W91B4L-11-A-0034 (14 task...orders) are no longer active. However, W91B4L-11-A-0033 (currently 117 task orders) and W91B4L-11-A-0037 (currently 198 task orders) are active BPAs

75 FR 4578 - Extension of Agency Information Collection Activity Under OMB Review: National Explosives...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-28

... Information Collection Activity Under OMB Review: National Explosives Detection Canine Team Program (NEDCTP... under the National Explosives Detection Canine Team Program. The data is collected electronically... feedback to the Chief of the National Explosives Detection Canine Team Program and instructional staff and...

Human Health and Ecological Risk Assessment for the Operation of the Explosives Waste Treatment Facility at Site 300 of the Lawrence Livermore National Laboratory Volume 1: Report of Results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gallegos, G; Daniels, J; Wegrecki, A

2006-04-24

This document contains the human health and ecological risk assessment for the Resource Recovery and Conservation Act (RCRA) permit renewal for the Explosives Waste Treatment Facility (EWTF). Volume 1 is the text of the risk assessment, and Volume 2 (provided on a compact disc) is the supporting modeling data. The EWTF is operated by the Lawrence Livermore National Laboratory (LLNL) at Site 300, which is located in the foothills between the cities of Livermore and Tracy, approximately 17 miles east of Livermore and 8 miles southwest of Tracy. Figure 1 is a map of the San Francisco Bay Area, showingmore » the location of Site 300 and other points of reference. One of the principal activities of Site 300 is to test what are known as ''high explosives'' for nuclear weapons. These are the highly energetic materials that provide the force to drive fissionable material to criticality. LLNL scientists develop and test the explosives and the integrated non-nuclear components in support of the United States nuclear stockpile stewardship program as well as in support of conventional weapons and the aircraft, mining, oil exploration, and construction industries. Many Site 300 facilities are used in support of high explosives research. Some facilities are used in the chemical formulation of explosives; others are locations where explosive charges are mechanically pressed; others are locations where the materials are inspected radiographically for such defects as cracks and voids. Finally, some facilities are locations where the machined charges are assembled before they are sent to the on-site test firing facilities, and additional facilities are locations where materials are stored. Wastes generated from high-explosives research are treated by open burning (OB) and open detonation (OD). OB and OD treatments are necessary because they are the safest methods for treating explosives wastes generated at these facilities, and they eliminate the requirement for further handling and transportation that would be required if the wastes were treated off site.« less

Human Health and Ecological Risk Assessment for the Operation of the Explosives Waste Treatment Facility at Site 300 of the Lawrence Livermore National Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gallegos, G; Daniels, J; Wegrecki, A

2007-10-01

This document contains the human health and ecological risk assessment for the Resource Recovery and Conservation Act (RCRA) permit renewal for the Explosives Waste Treatment Facility (EWTF). Volume 1 is the text of the risk assessment, and Volume 2 (provided on a compact disc) is the supporting modeling data. The EWTF is operated by the Lawrence Livermore National Laboratory (LLNL) at Site 300, which is located in the foothills between the cities of Livermore and Tracy, approximately 17 miles east of Livermore and 8 miles southwest of Tracy. Figure 1 is a map of the San Francisco Bay Area, showingmore » the location of Site 300 and other points of reference. One of the principal activities of Site 300 is to test what are known as 'high explosives' for nuclear weapons. These are the highly energetic materials that provide the force to drive fissionable material to criticality. LLNL scientists develop and test the explosives and the integrated non-nuclear components in support of the United States nuclear stockpile stewardship program as well as in support of conventional weapons and the aircraft, mining, oil exploration, and construction industries. Many Site 300 facilities are used in support of high explosives research. Some facilities are used in the chemical formulation of explosives; others are locations where explosive charges are mechanically pressed; others are locations where the materials are inspected radiographically for such defects as cracks and voids. Finally, some facilities are locations where the machined charges are assembled before they are sent to the onsite test firing facilities, and additional facilities are locations where materials are stored. Wastes generated from high-explosives research are treated by open burning (OB) and open detonation (OD). OB and OD treatments are necessary because they are the safest methods for treating explosives wastes generated at these facilities, and they eliminate the requirement for further handling and transportation that would be required if the wastes were treated off site.« less

78 FR 76860 - Agency Information Collection Activities; Proposed Collection; Comments Requested: Inventories...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-19

...] Agency Information Collection Activities; Proposed Collection; Comments Requested: Inventories, Licensed... currently approved collection. (2) Title of the Form/Collection: Inventories, Licensed Explosives Importers... explosive material inventories of those persons engaged in various activities within the explosives industry...

Cycles of explosive and effusive eruptions at Kīlauea Volcano, Hawai‘i

USGS Publications Warehouse

Swanson, Don; Rose, Timothy R.; Mucek, Adonara E; Garcia, Michael O.; Fiske, Richard S.; Mastin, Larry G.

2014-01-01

The subaerial eruptive activity at Kīlauea Volcano (Hawai‘i) for the past 2500 yr can be divided into 3 dominantly effusive and 2 dominantly explosive periods, each lasting several centuries. The prevailing style of eruption for 60% of this time was explosive, manifested by repeated phreatic and phreatomagmatic activity in a deep summit caldera. During dominantly explosive periods, the magma supply rate to the shallow storage volume beneath the summit dropped to only a few percent of that during mainly effusive periods. The frequency and duration of explosive activity are contrary to the popular impression that Kīlauea is almost unceasingly effusive. Explosive activity apparently correlates with the presence of a caldera intersecting the water table. The decrease in magma supply rate may result in caldera collapse, because erupted or intruded magma is not replaced. Glasses with unusually high MgO, TiO2, and K2O compositions occur only in explosive tephra (and one related lava flow) and are consistent with disruption of the shallow reservoir complex during caldera formation. Kīlauea is a complex, modulated system in which melting rate, supply rate, conduit stability (in both mantle and crust), reservoir geometry, water table, and many other factors interact with one another. The hazards associated with explosive activity at Kīlauea’s summit would have major impact on local society if a future dominantly explosive period were to last several centuries. The association of lowered magma supply, caldera formation, and explosive activity might characterize other basaltic volcanoes, but has not been recognized.

Sulfur activation at the Little Boy-Comet Critical Assembly: a replica of the Hiroshima bomb

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kerr, G.D.; Emery, J.F.; Pace, J.V. III

1985-04-01

Studies have been completed on the activation of sulfur by fast neutrons from the Little Boy-Comet Critical Assembly which replicates the general features of the Hiroshima bomb. The complex effects of the bomb's design and construction on leakage of sulfur-activation neutrons were investigated both experimentally and theoretically. Our sulfur activation studies were performed as part of a larger program to provide benchmark data for testing of methods used in recent source-term calculations for the Hiroshima bomb. Source neutrons capable of activating sulfur play an important role in determining neutron doses in Hiroshima at a kilometer or more from the pointmore » of explosion. 37 refs., 5 figs., 6 tabs.« less

Building firelines with liquid explosive ... some preliminary results

Treesearch

John D. Dell; Franklin R. Ward

1970-01-01

Building firelines in logging slash or dense brush can be costly and hazardous. A new liquid explosive was tested in these and other forest fuel types, It proved effective in brush, understory vegetation, and light-medium slash, but was not effective in deep, heavy slash. Fireline construction by this technique shows promise, but will require more testing and...

The physical volcanology of Mars

NASA Technical Reports Server (NTRS)

Mouginis-Mark, Peter J.; Wilson, Lionel; Zuber, Maria T.

1992-01-01

The physical volcanology of Mars is reviewed, with particular attention given to the diversity of volcanic landforms, the implied styles of eruption associated with the construction of these landforms, the inferred internal structure of the volcanoes, and the influence that the eruptions have had on the Martian environment (both local and global in scale). Volcanism in the central highlands appears to have been explosive in character, while most of the constructional activity in the northern plains was effusive. Highlands volcanism appears to be relatively old compared to that in the northern hemisphere. There is evidence for the existence of large magma chambers and very high effusion rate eruptions on Mars. Tectonic deformation associated with volcanic constructs is primarily a consequence of loading and magma transport, while deformation in the volcanic plains reflects stresses associated with Tharsis and major impact basins.

An integral condition for core-collapse supernova explosions

DOE PAGES

Murphy, Jeremiah W.; Dolence, Joshua C.

2017-01-10

Here, we derive an integral condition for core-collapse supernova (CCSN) explosions and use it to construct a new diagnostic of explodability. The fundamental challenge in CCSN theory is to explain how a stalled accretion shock revives to explode a star. In this manuscript, we assume that the shock revival is initiated by the delayed-neutrino mechanism and derive an integral condition for spherically symmetric shock expansion, v s > 0. One of the most useful one-dimensional explosion conditions is the neutrino luminosity and mass-accretion rate (more » $${L}_{\

Fluid blade disablement tool

DOEpatents

Jakaboski, Juan-Carlos [Albuquerque, NM; Hughs, Chance G [Albuquerque, NM; Todd, Steven N [Rio Rancho, NM

2012-01-10

A fluid blade disablement (FBD) tool that forms both a focused fluid projectile that resembles a blade, which can provide precision penetration of a barrier wall, and a broad fluid projectile that functions substantially like a hammer, which can produce general disruption of structures behind the barrier wall. Embodiments of the FBD tool comprise a container capable of holding fluid, an explosive assembly which is positioned within the container and which comprises an explosive holder and explosive, and a means for detonating. The container has a concavity on the side adjacent to the exposed surface of the explosive. The position of the concavity relative to the explosive and its construction of materials with thicknesses that facilitate inversion and/or rupture of the concavity wall enable the formation of a sharp and coherent blade of fluid advancing ahead of the detonation gases.

Seismic activity that accompanied the effusive and explosive eruptions during the 2004-2005 period at Volcán de Colima, Mexico

NASA Astrophysics Data System (ADS)

Arámbula-Mendoza, R.; Lesage, P.; Valdés-González, C.; Varley, N. R.; Reyes-Dávila, G.; Navarro, C.

2011-08-01

Volcán de Colima is considered the most active in Mexico. A period of large eruptive activity occurred in 2004-2005. It began as a swarm of long-period events (LPs) in late September 2004, indicating the onset of growth of a new lava dome in its crater. Subsequently, avalanches of incandescent material and pyroclastic flows during a period of approximately 2 months occurred. Then, the activity became more explosive with moderate explosions. Finally, swarms of LPs accompanied the magma ascent and extrusion of small domes and vulcanian explosions with pyroclastic flows in 2005. This eruptive period was investigated with a continuous seismic signal study, cross-correlation of LPs and autoregressive analysis of monochromatic LPs. For the vast majority of the explosions, an increase in the rate of seismic energy was observed with the Seismic Spectral Energy Measurement (SSEM) from 1 to 3 Hz, before each explosive event. This increase in energy is proportional to the increase in the rate of LPs, probably as a result of an increase in the emission rate. Applying the material failure forecasting method (FFM) and using SSEM inverse of parameter, the time of the explosions is estimated as the time when the adjusted line reaches the null value. We observe a systematic delay of a few hours between the real time of occurrence of the explosions and the estimated time. This suggests that more complex processes than pure damaging of the plug occur before the explosions. The swarms associated with the large explosions include a large proportion of LPs with similar waveforms. They form a dozen of families which stay during the whole period of activity and which indicate repetitive sources. Some of the families are active only before the explosions and could therefore be used as early warning. Monochromatic LP events occurred during this period, some of them just some hours before an explosion. However, no clear relationship between their occurrence and the explosions could be found.

Computational State Space Models for Activity and Intention Recognition. A Feasibility Study

PubMed Central

Krüger, Frank; Nyolt, Martin; Yordanova, Kristina; Hein, Albert; Kirste, Thomas

2014-01-01

Background Computational state space models (CSSMs) enable the knowledge-based construction of Bayesian filters for recognizing intentions and reconstructing activities of human protagonists in application domains such as smart environments, assisted living, or security. Computational, i. e., algorithmic, representations allow the construction of increasingly complex human behaviour models. However, the symbolic models used in CSSMs potentially suffer from combinatorial explosion, rendering inference intractable outside of the limited experimental settings investigated in present research. The objective of this study was to obtain data on the feasibility of CSSM-based inference in domains of realistic complexity. Methods A typical instrumental activity of daily living was used as a trial scenario. As primary sensor modality, wearable inertial measurement units were employed. The results achievable by CSSM methods were evaluated by comparison with those obtained from established training-based methods (hidden Markov models, HMMs) using Wilcoxon signed rank tests. The influence of modeling factors on CSSM performance was analyzed via repeated measures analysis of variance. Results The symbolic domain model was found to have more than states, exceeding the complexity of models considered in previous research by at least three orders of magnitude. Nevertheless, if factors and procedures governing the inference process were suitably chosen, CSSMs outperformed HMMs. Specifically, inference methods used in previous studies (particle filters) were found to perform substantially inferior in comparison to a marginal filtering procedure. Conclusions Our results suggest that the combinatorial explosion caused by rich CSSM models does not inevitably lead to intractable inference or inferior performance. This means that the potential benefits of CSSM models (knowledge-based model construction, model reusability, reduced need for training data) are available without performance penalty. However, our results also show that research on CSSMs needs to consider sufficiently complex domains in order to understand the effects of design decisions such as choice of heuristics or inference procedure on performance. PMID:25372138

FY 1999 Pollution Prevention and Environmental Technology Division

DTIC Science & Technology

2000-01-01

Volatilization Devices 38 Phytoremediation of Explosives in Groundwater Using Constructed Wetlands 39 Phytoremediation of Lead in Soil 42 Range Rule Risk...fees for green- waste disposal. Del Monte Fresh Produce, Inc. is conducting a field demonstration of phytoremediation to treat groundwater...soils • Phytoremediation of explosives-contaminated soils The University of Hawaii has added summaries of ABRP projects under its Bioremediation

Morphological analysis of Cerro Bravo Volcano, Central Andes of Colombia

NASA Astrophysics Data System (ADS)

Arango-Palacio, E.; Murcia, H. F.; Robayo, C.; Chica, P.; Piedrahita, D. A.; Aguilar-Casallas, C.

2017-12-01

Keywords: Cerro Bravo Volcano, Volcanic landforms, Craters. Cerro Bravo Volcano (CBV) belongs to the San Diego-Cerro Machín Volcano - Tectonic Province in the Central Andes of Colombia. CVB is located 150 km NW from Bogotá, the capital of Colombia, and 25 km E from Manizales city ( 350,00 inhabitants). The volcanic activity of CBV began at 50,000 years ago and has been characterized by produce effusive and explosive (subplinian to plinian) eruptions with dacitic and andesitic in composition products. The effusive activity is evidenced by lava flows and lava domes, while the explosive activity is evidenced by pyroclastic density current deposits and pyroclastic fall deposits; some secondary deposits such as debris avalanches and lahares has been also recognised. Currently, the CBV is considered as a hazard for the Manizales city. In order to characterise the volcanic edifice, a morphological analysis was carried out and a map was created from a digital elevations model (DEM) with 12.5 m resolution as well as aerial photographs. Thus, it was possible to associate the landforms with the evolution of the volcano. Based on this analysis, it was possible to identify the base and top of the CBV edifice as 2400 and 4020 m.a.s.l., respectively, with a diameter in its major axis of 5.8 km. The volcanic edifice has four main craters opening to the north. The craters are apart from each other by heights and distances between 120 m.a.s.l. and 1 km, respectively; this geomorphology is an evidence of different eruptive stages of the volcano construction. Morphological analysis has shown that some craters were created from explosive eruptions, however the different heights between each crater suggest the creation of lava domes and their collapse as a response of the final effusive activity.

Semiconductor bridge (SCB) igniter

DOEpatents

Bickes, Jr., Robert W.; Schwarz, Alfred C.

1987-01-01

In an explosive device comprising an explosive material which can be made to explode upon activation by activation means in contact therewith; electrical activation means adaptable for activating said explosive material such that it explodes; and electrical circuitry in operation association with said activation means; there is an improvement wherein said activation means is an electrical material which, at an elevated temperature, has a negative temperature coefficient of electrical resistivity and which has a shape and size and an area of contact with said explosive material sufficient that it has an electrical resistance which will match the resistance requirements of said associated electrical circuitry when said electrical material is operationally associated with said circuitry, and wherein said electrical material is polycrystalline; or said electrical material is crystalline and (a) is mounted on a lattice matched substrate or (b) is partially covered with an intimately contacting metallization area which defines its area of contact with said explosive material.

Modeling of Small Martian Volcanoes: A Changing View of Volcanic Shield and Cone Fields

NASA Astrophysics Data System (ADS)

Sakimoto, S. E.; Bradley, B. A.; Garvin, J. B.

2001-05-01

The small volcanic features on Mars (channels, flows, shields, and cratered cones) are key to understanding eruption styles, rates, and volumes because they are ubiquitous and simple enough to attempt modeling. Several of these small features have been suggested to be geologically recent [1,2,3]. This study measures and models small (3-50 km) volcanic edifices. Recent Mars Global Surveyor data reveal that these small features are more common that we had previously thought from the lower resolution Viking mission data (e.g., [3,4]). Furthermore, there are clear geometric differences in the Mars Orbiter Laser Altimeter (MOLA) data between regions suggesting local and regional eruption styles may vary with latitude. While a few of the pre-MGS construction models predict the martian mid-latitude volcanic shield shapes fairly well, the small explosive volcanic edifice shapes were not well predicted by existing models (see[5]), and there are a host of types-mostly polar-that are not well described by prior modeling. We compare small edifice construction model results for a percolation style model of effusive and mixed effusive and explosive edifices to prior model results for several martian volcanic regions. While mid-latitude edifices match well to predicted cross-section shapes, steeper flank slopes (See [6]; Glaze and Sakimoto, this volume) for the polar edifices suggest that the magma supply rate or the edifice permeability may be higher in the polar regions for some edifices types. However, polar edifice flank slopes do not commonly reach the greater than 10 degree flanks expected from prior explosive edifice models. Additionally, we do not observe shallow flank slope shields in the polar regions. This suggests that simple shield building may be significantly influenced or modified by volatile involvement near the martian poles, while a range of poorly understood explosive activity may be active in both regions. [1] Keszthelyi et al. JGR 105, 15027-15049, 2000. [2] Hartmann and Berman, JGR, 105, 15011-15025, 2000. [3] Garvin, et al., Icarus, 145, 648-652, 2000. [4] Sakimoto, et al., LPSC XXXII, CDROM, abstract #1808, 2001. [5] Glaze and Baloga LPSC XXXII, CDROM, abstract #1209, 2001. [6] Wong, et al., LPSC XXXII, CDROM, abstract #1563, 2001.

Non-focusing active warhead

DOEpatents

Hornig, H.C.

1998-12-22

A non-nuclear, non-focusing, active warhead that comprises a high explosive charge contained within a casing of reactive metal is disclosed. When the high explosive is detonated, the reactive metal is dispersed and reacts with the air, which significantly increases the explosive yield of the warhead. The active warhead produces therefore much higher blast effects with significantly reduced weight compared to conventional munitions. The warhead is highly effective against such targets as aircraft which typically have thin fuselages, for example. The explosiveness of this warhead can be enhanced further by elevating the temperature and therefore the reactivity of the reactive metal before or during the explosion. New methods of enhancing the reactivity of the metal are also taught. 4 figs.

Non-focusing active warhead

DOEpatents

Hornig, Howard C.

1998-01-01

A non-nuclear, non-focusing, active warhead that comprises a high explosive charge contained within a casing of reactive metal. When the high explosive is detonated, the reactive metal is dispersed and reacts with the air, which significantly increases the explosive yield of the warhead. The active warhead produces therefore much higher blast effects with significantly reduced weight compared to conventional munitions. The warhead is highly effective against such targets as aircraft which typically have thin fuselages, for example. The explosiveness of this warhead can be enhanced further by elevating the temperature and therefore the reactivity of the reactive metal before or during the explosion. New methods of enhancing the reactivity of the metal are also taught.

75 FR 2490 - Taking and Importing Marine Mammals; Naval Explosive Ordnance Disposal School Training Operations...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-15

... Importing Marine Mammals; Naval Explosive Ordnance Disposal School Training Operations Activities at Eglin...) for authorization to take marine mammals, by harassment, incidental to Naval Explosive Ordnance Disposal School (NEODS) training operations, military readiness activities, at Eglin AFB, FL from...

Optimizing post activation potentiation for explosive activities in competitive sports

PubMed Central

Gołaś, Artur; Maszczyk, Adam; Mikołajec, Kazimierz; Stastny, Petr

2016-01-01

Abstract Post activation potentiation (PAP) has shown improved performance during movements requiring large muscular power output following contractions under near maximal load conditions. PAP can be described as an acute enhancement of performance or an enhancement of factors determining an explosive sports activity following a preload stimulus. In practice, PAP has been achieved by complex training, which involves a combination of a heavy loaded exercise followed by a biomechanically similar explosive activity, best if specific for a particular sport discipline. The main objective of this study was to investigate the effects of PAP on performance in explosive motor activities specific for basketball, luge and athletics throws. The novel approach to the experiments included individualized recovery time (IRT) between the conditioning exercise and the explosive activity. Additionally, the research groups were homogenous and included only competitive athletes of similar age and training experience. Thirty one well trained athletes from 3 different sport disciplines participated in the study. All athletes performed a heavy loaded conditioning activity (80-130%1RM) followed by a biomechanically similar explosive exercise, during which power (W) or the rate of power development (W/s/kg) was evaluated. The results of our experiment confirmed the effectiveness of PAP with well-trained athlets during explosive motor activities such as jumping, throwing and pushing. Additionally, our research showed that eccentric supramaximal intensities (130% 1RM) can be effective in eliciting PAP in strength trained athletes. Our experiments also showed that the IRT should be individualized because athletes differ in the strength level, training experience and muscle fiber structure. In the three experiments conducted with basketball players, track and field athletes and luge athletes, the optimal IRT equaled 6 min. This justifies the need to individualize the volume and intensity of the CA, and especially the IRT, between the CA and the explosive activity. PMID:28149397

Experimental investigation of turbulent mixing in post-explosion environment

NASA Astrophysics Data System (ADS)

Smith, Josh; Hargather, Michael

2015-11-01

Experiments are performed to investigate the turbulent mixing of product gases and the ambient environment in a post-explosion environment. The experiments are performed in a specially constructed shock tunnel where thermite-enhanced explosions are set off. The explosives are detonated at one end of the tunnel, producing a one-dimensional shock wave and product gas expansion which moves toward the open end of the tunnel. Optical diagnostics are applied to study the shock wave motion and the turbulent mixing of the gases after the detonation. Results are presented for schlieren, shadowgraph, and interferometry imaging of the expanding gases with simultaneous pressure measurements. An imaging spectrometer is used to identify the motion of product gas species. Results show varying shock speed with thermite mass and the identification of turbulent mixing regions.

Stress-induced activation of decomposition of organic explosives: a simple way to understand.

PubMed

Zhang, Chaoyang

2013-01-01

We provide a very simply way to understand the stress-induced activation of decomposition of organic explosives by taking the simplest explosive molecule nitromethane (NM) as a prototype and constraining one or two NM molecules in a shell to represent the condensed phrase of NM against the stress caused by tension and compression, sliding and rotational shear, and imperfection. The results show that the stress loaded on NM molecule can always reduce the barriers of its decomposition. We think the origin of this stress-induced activation is due to the increased repulsive intra- and/or inter- molecular interaction potentials in explosives resulted from the stress, whose release is positive to accelerate the decomposition. Besides, by these models, we can understand that the explosives in gaseous state are easier to analyze than those in condensed state and the voids in condensed explosives make them more sensitive to external stimuli relative to the perfect crystals.

Multichannel Discriminative Detection of Explosive Vapors with an Array of Nanofibrous Membranes Loaded with Quantum Dots.

PubMed

Wu, Zhaofeng; Duan, Haiming; Li, Zhijun; Guo, Jixi; Zhong, Furu; Cao, Yali; Jia, Dianzeng

2017-11-20

The multichannel fluorescent sensor array based on nanofibrous membranes loaded with ZnS quantum dots (QDs) was created and demonstrated for the discriminative detection of explosives. The synergistic effect of the high surface-to-volume ratio of QDs, the good permeability of nanofibrous membranes and the differential response introduced by surface ligands was played by constructing the sensing array using nanofibrous membranes loaded with ZnS QDs featuring several surface ligands. Interestingly, although the fluorescence quenching of the nanofibrous membranes is not linearly related to the exposure time, the fingerprint of each explosive at different times is very similar in shape, and the fingerprints of the three explosives show different shapes. Three saturated vapors of nitroaromatic explosives could be reliably detected and discriminated by the array at room temperature. This work is the first step toward devising a monitoring system for explosives in the field of public security and defense. It could, for example, be coupled with the technology of image recognition and large data analysis for a rapid diagnostic test of explosives. This work further highlights the power of differential, multichannel arrays for the rapid and discriminative detection of a wide range of chemicals.

Multichannel Discriminative Detection of Explosive Vapors with an Array of Nanofibrous Membranes Loaded with Quantum Dots

PubMed Central

Wu, Zhaofeng; Duan, Haiming; Li, Zhijun; Guo, Jixi; Zhong, Furu; Cao, Yali; Jia, Dianzeng

2017-01-01

The multichannel fluorescent sensor array based on nanofibrous membranes loaded with ZnS quantum dots (QDs) was created and demonstrated for the discriminative detection of explosives. The synergistic effect of the high surface-to-volume ratio of QDs, the good permeability of nanofibrous membranes and the differential response introduced by surface ligands was played by constructing the sensing array using nanofibrous membranes loaded with ZnS QDs featuring several surface ligands. Interestingly, although the fluorescence quenching of the nanofibrous membranes is not linearly related to the exposure time, the fingerprint of each explosive at different times is very similar in shape, and the fingerprints of the three explosives show different shapes. Three saturated vapors of nitroaromatic explosives could be reliably detected and discriminated by the array at room temperature. This work is the first step toward devising a monitoring system for explosives in the field of public security and defense. It could, for example, be coupled with the technology of image recognition and large data analysis for a rapid diagnostic test of explosives. This work further highlights the power of differential, multichannel arrays for the rapid and discriminative detection of a wide range of chemicals. PMID:29156627

Thermonuclear Explosions from Hybrid C/O/Ne White Dwarf Progenitors Ignited Centrally After Interior Mixing

NASA Astrophysics Data System (ADS)

Augustine, Carlyn

2018-01-01

Type Ia Supernovae are thermonuclear explosions of white dwarf (WD) stars. Past studies predict the existence of "hybrid" white dwarfs, made of a C/O/Ne core with a O/Ne shell, and that these are viable progenitors for supernovae. More recent work found that the C/O core is mixed with the surrounding O/Ne while the WD cools. Inspired by this scenario, we performed simulations of thermonuclear supernovae in the single degenerate paradigm from these hybrid progenitors. Our investigation began by constructing a hybrid white dwarf model with the one-dimensional stellar evolution code MESA. The model was allowed to go through unstable interior mixing ignite carbon burning centrally. The MESA model was then mapped to a two-dimensional initial condition and an explosion simulated from that with FLASH. For comparison, a similar simulation of an explosion was performed from a traditional C/O progenitor WD. Comparing the yields produced by explosion simulations allows us to determine which model produces more 56Ni, and therefore brighter events, and how explosions from these models differ from explosions from previous models without the mixing during the WD cooling.

Elaboration of the Charge Constructions of Explosives for the Structure of Facing Stone

NASA Astrophysics Data System (ADS)

Khomeriki, Sergo; Mataradze, Edgar; Chikhradze, Nikoloz; Losaberidze, Marine; Khomeriki, Davit; Shatberashvili, Grigol

2017-12-01

Increased demand for high-strength facing material caused the enhancement of the volume of explosives use in modern technologies of blocks production. The volume of broken rocks and crushing quality depends on the rock characteristics and on the properties of the explosive, in particular on its brisance and serviceability. Therefore, the correct selection of the explosive for the specific massif is of a considerable practical importance. For efficient mining of facing materials by explosion method the solving of such problems as determination of the method of blasthole drilling as well as of the regime and charge values, selection of the explosive, blastholes distribution in the face and their order is necessary. This paper focuses on technical solutions for conservation of rock natural structure in the blocks of facing material, mined by the use of the explosives. It has been established that the efficient solving of mentioned problem is attained by reducing of shock pulse duration. In such conditions the rigidity of crystalline lattice increases in high pressure area. As a result, the hazard if crack formation in structural unites and the increases of natural cracks are excluded. Short-time action of explosion pulse is possible only by linear charges of the explosives, characterized by high detonation velocity which detonate by the velocity of 7-7.5 km/sec and are characterized by very small critical diameter.

Conduit Wall Failure as a Trigger for Transition From Strombolian to Phreatomagmatic Explosive Activity in the Cova de Paúl Crater Eruption on Santo Antão, Cape Verde Islands

NASA Astrophysics Data System (ADS)

Tarff, R. W.; Day, S. J.

2011-12-01

Episodes of hazardous phreatomagmatic explosive activity, including Surtseyan activity, occur within otherwise less dangerous effusive to mildly explosive magmatic eruptions at high-elevation vents on many oceanic island volcanoes. The water driving these explosions is sourced from freshwater aquifers within the volcanic edifices. Understanding volcanic and geophysical precursors to, and mechanisms of, the (frequently abrupt) transitions to explosive activity is required as a basis for effective warning and mitigation of the resulting hazards. Here we describe near-vent deposits around the large Cova de Paúl crater on the island of Santo Antão, Cape Verde Islands, which provide some insights into a transition from mild magmatic to violently explosive phreatomagmatic activity in one such eruption. This pre-historic but well-preserved crater formed in a single eruption that produced extensive low-temperature, lithic-rich phreatomagmatic pyroclastic flows and surge deposits; these are interbedded in proximal outcrops with airfall breccia and ash beds containing varying proportions of lithic and juvenile clasts, pointing to a series of climactic explosions within an extended period of milder explosive activity of broadly Surtseyan type. Prior to the transition to phreatomagmatic activity, the eruption had been characterized by mild Strombolian activity that produced scoria and spatter deposits of broadly tephritic composition. The Strombolian deposits contain a distinct population of strongly banded, low-vesicularity angular clasts with strongly prolate vesicles and a notably glassy appearance. These became markedly larger and more abundant just below the transition to the phreatomagmatic deposits. Comparisons of these clasts with the Strombolian scoria suggest that they are fragments of flow-banded chilled margins from the walls of the eruptive conduit. Thermal shattering of these margins to produce the angular glassy clasts may record the onset of groundwater flow into the conduit, leading to the phreatomagmatic explosive phase of the eruption. Fragmentation of the conduit wall and ingress of groundwater would likely have been accompanied by seismic swarms consisting of high-frequency fracture events and episodes of harmonic tremor, pointing to a potential geophysical signature of the onset of phreatomagmatic explosive activity in comparable future eruptions on Santo Antão and other oceanic islands.

Analyses of Etna Eruptive Activity From 18th Century and Characterization of Flank Eruptions

NASA Astrophysics Data System (ADS)

del Carlo, P.; Branca, S.; Coltelli, M.

2003-12-01

Etna explosive activity has usually been considered subordinate with respect to the effusive eruptions. Nevertheless, in the last decade and overall after the 2001 and 2002 flank eruptions, explosive activity has drawn the attention of the scientific and politic communities owing to the damages that the long-lasting ash fall caused to Sicily's economy. We analyzed the eruptions from the 18th century to find some analogous behavior of Etna in the past. A study of the Etna historical record (Branca and Del Carlo, 2003) evidenced that after the 1727 eruption, there are no more errors in the attribution of the year of the eruption. Furthermore from this time on, the scientific quality of the chronicles allowed us to obtain volcanological information and to estimate the magnitude of the major explosive events. The main goal of this work was to characterize the different typologies of Etna eruptions in the last three centuries. Meanwhile, we have tried to find the possible relationship between the two kinds of activity (explosive and effusive) in order to understand the complexity of the eruptive phenomena and define the short-term behavior of Etna. On the base of the predominance of the eruptive typology (effusive or explosive) we have classified the flank eruptions in three classes: i) Type 1: almost purely effusive; ii) Type 2: the intensity of explosive activity comparable with the effusive; iii) Type 3: almost purely explosive with minor lava effusion (only the 1763 La Montagnola and 2002 eruptions belong to this class). Long-lasting explosive activity is produced by flank eruptions with continuous ash emission and prolonged fallout on the flanks (e.g. 1763, 1811, 1852-53, 1886, 1892, 2001 and 2002 eruptions). At summit craters continuous activity is weaker, whereas the strongest explosive eruptions are short-lived events. Furthermore, from the 18th to 20th century there were several years of intense and discontinuous summit explosive activity, from high strombolian to fire fountain. This activity produced abundant ash fall in the whole volcano area reaching the Calabria region and Malta Island. Generally, some of these periods preceded important flank eruptions. Concerning the occurrence of the higher magnitude explosive events, we observe that at least one subplinian eruption occurred both in the 18th and 19th centuries. In the 20th century the increased quality of the scientific reports has allowed to recognize 6 subplinian eruptions from summit craters.

Persistent explosive activity at Stromboli investigated with OP-FTIR and SO2 cameras

NASA Astrophysics Data System (ADS)

Burton, M. R.; La Spina, A.; Sawyer, G. M.; Harris, A. J.

2012-12-01

Stromboli volcano in Italy exhibits what is perhaps one of the most well-known examples of cyclic activity, in the form of its regular explosions, which send a few m3 of material 100-200 m into the air every 10-20 minutes. Recent developments in measurements of volatile release from Stromboli using a series of novel approaches have allowed this cyclic behaviour to be examined in detail. In particular, the use of an automated OP-FTIR has revealed unprecedented detail in the dynamics of degassing from individual craters at the summit of Stromboli. Furthermore, the variations in composition of explosive degassing from Stromboli demonstrate a deep source ~2 km for the gas slugs which produce explosions at this volcano, in contrast to the commonly-held view that gas coalescence at shallow depth is responsible for the behaviour. The SO2 camera has revealed fascinating new details on the dynamics of degassing at Stromboli, and has allowed direct quantification of the amount of gas released during explosions and through quiescent degassing. The remarkable observation that 99% of degassing takes place quiescently, and that the explosions, whilst apparently more significant, are in fact a secondary process compared with the mass and energy involved in background, quiet processes. The new insight that the explosions are actually only a relatively minor aspect of the activity (in terms of mass and energy) actually makes the regularity of the cyclic explosive activity still more remarkable. In this paper we present a detailed overview of the state of the art of our understanding of cyclic explosive activity at Stromboli volcano from the perspective of recent advances in geochemical monitoring of the gas emissions. We also report initial results from a multidisciplinary campaign on Stromboli which utilised both OP-FTIR and SO2 camera techniques.

Computing Q-D Relationships for Storage of Rocket Fuels

NASA Technical Reports Server (NTRS)

Jester, Keith

2005-01-01

The Quantity Distance Measurement Tool is a GIS BASEP computer program that aids safety engineers by calculating quantity-distance (Q-D) relationships for vessels that contain explosive chemicals used in testing rocket engines. (Q-D relationships are standard relationships between specified quantities of specified explosive materials and minimum distances by which they must be separated from persons, objects, and other explosives to obtain specified types and degrees of protection.) The program uses customized geographic-information-system (GIS) software and calculates Q-D relationships in accordance with NASA's Safety Standard For Explosives, Propellants, and Pyrotechnics. Displays generated by the program enable the identification of hazards, showing the relationships of propellant-storage-vessel safety buffers to inhabited facilities and public roads. Current Q-D information is calculated and maintained in graphical form for all vessels that contain propellants or other chemicals, the explosiveness of which is expressed in TNT equivalents [amounts of trinitrotoluene (TNT) having equivalent explosive effects]. The program is useful in the acquisition, siting, construction, and/or modification of storage vessels and other facilities in the development of an improved test-facility safety program.

Explosive safety criteria at a Department of Energy contractor facility

NASA Astrophysics Data System (ADS)

Krach, F.

1984-08-01

Monsanto Research Corporation (MRC) operates the Mound facility in Miamisburg, Ohio, for the Department of Energy. Small explosive components are manufactured at MRC, and stringent explosive safety criteria have been developed for their manufacturing. The goals of these standards are to reduce employee injuries and eliminate fenceline impacts resulting from accidental detonations. The manner in which these criteria were developed and what DOD standards were incorporated into MRC's own design criteria are described. These design requirements are applicable to all new construction at MRC. An example of the development of the design of a Component Test Facility is presented to illustrate the application of the criteria.

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

USGS Publications Warehouse

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.

46 CFR 194.10-1 - Application.

Code of Federal Regulations, 2010 CFR

2010-10-01

... CONTROL OF EXPLOSIVES AND OTHER HAZARDOUS MATERIALS Magazines § 194.10-1 Application. (a) The provisions of this subpart apply to the construction of integral magazines, magazine vans, and magazine chests... construction of magazines shall be in accordance with the applicable provisions of 49 CFR parts 173 and 176 and...

Distribution of Ejecta in Analog Tephra Rings from Discrete Single and Multiple Subsurface Explosions

NASA Astrophysics Data System (ADS)

Graettinger, A. H.; Valentine, G. A.; Sonder, I.; Ross, P. S.; White, J. D. L.

2015-12-01

Buried-explosion experiments were used to investigate the spatial and volumetric distribution of extra-crater ejecta resulting from a range of explosion configurations with and without a crater present. Explosion configuration is defined in terms of scaled depth, the relationship between depth of burial and the cube root of explosion energy, where an optimal scaled depth explosion produces the largest crater diameter for a given energy. The multiple explosion experiments provide an analog for the formation of maar-diatreme ejecta deposits and the deposits of discrete explosions through existing conduits and hydrothermal systems. Experiments produced meter-sized craters with ejecta distributed between three major facies based on morphology and distance from the crater center. The proximal deposits form a constructional steep-sided ring that extends no more than two-times the crater radius away from center. The medial deposits form a low-angle continuous blanket that transitions with distance into the isolated clasts of the distal ejecta. Single explosion experiments produce a trend of increasing volume proportion of proximal ejecta as scaled depth increases (from 20-90% vol.). Multiple explosion experiments are dominated by proximal deposits (>90% vol.) for all but optimal scaled depth conditions (40-70% vol.). In addition to scaled depth, the presence of a crater influences jet shape and how the jet collapses, resulting in two end-member depositional mechanisms that produce distinctive facies. The experiments use one well-constrained explosion mechanism and, consequently, the variations in depositional facies and distribution are the result of conditions independent of that mechanism. Previous interpretations have invoked variations in fragmentation as the cause of this variability, but these experiments should help with a more complete reconstruction of the configuration and number of explosions that produce a tephra ring.

Health-hazard evaluation report HETA 91-338-2187, IMC Corporation, Sterlington, Louisiana

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kiefer, M.; Tepper, A.; Miller, R.

1992-03-01

In response to a request from an authorized representative of the Construction and General Laborers Union, Local 762, an investigation was made of potential hazards for asbestos abatement contract workers at IMC Corporation, (SIC-2869), Sterlington, Louisiana. The IMC facility consisted of two ammonia facilities, a nitroparaffin (NP) facility, and a NP derivatives facility. An explosion occurred on May 1, 1991 in the NP facility, caused by a faulty compressor. During the post explosion renovation activities, an asbestos abatement firm was working on site due to the large amounts of asbestos (1332214) insulation which had been disturbed by the explosion. Recordsmore » indicated that several workers complained of ill effects and odors on June 17 and 19. The incidents were investigated but no chemical exposure explanation was found. Routine and complaint based industrial hygiene monitoring was primarily area monitoring and not substance specific. Of the 25 workers interviewed, 22 had symptoms they felt were related to their work at IMC. The symptoms included those of the upper respiratory tract, central nervous system, and gastrointestinal system. The most common included diarrhea, nausea, headache, dizziness, and cough, each experienced by significantly more than half the subjects. The symptoms could not be linked conclusively to any specific chemical release, job task, work location, or food or drink source.« less

Emergency in-flight egress opening for general aviation aircraft. [pilot bailout

NASA Technical Reports Server (NTRS)

Bement, L. J.

1980-01-01

An emergency in-flight egress system was installed in a light general aviation airplane. The airplane had no provision for egress on the left side. To avoid a major structural redesign for a mechanical door, an add on 11.2 kg (24.6 lb) pyrotechnic-actuated system was developed to create an opening in the existing structure. The skin of the airplane was explosively severed around the side window, across a central stringer, and down to the floor, creating an opening of approximately 76 by 76 cm. The severed panel was jettisoned at an initial velocity of approximately 13.7 m/sec. System development included a total of 68 explosive severance tests on aluminum material using small samples, small and full scale flat panel aircraft structural mockups, and an actual aircraft fuselage. These tests proved explosive sizing/severance margins, explosive initiation, explosive product containment, and system dynamics. This technology is applicable to any aircraft of similar construction.

Short-lived eruptive episodes during the construction of a Na-alkalic basaltic field (Perşani Mountains, SE Transylvania, Romania)

NASA Astrophysics Data System (ADS)

Seghedi, Ioan; Popa, Răzvan-Gabriel; Panaiotu, Cristian G.; Szakács, Alexandru; Pécskay, Zoltán

2016-10-01

The Perşani Mts. basaltic field covers >176 km2 (~22 × 8 km) and is one of the youngest and biggest monogenetic volcanic fields in Southeastern Europe. It consists of 21 monogenetic volcanic centers, most of which were built on a basement of Miocene rhyolitic tuffs and Mesozoic sedimentary rocks. 40Ar/39Ar dating shows that the eruptions took place in five episodes: 1220, 1142, 1060, 800, and 683 ka. An additional undated episode at 1060-800 ka has been identified using volcanological observations. Initial phreatomagmatic activity was commonly followed by explosive Strombolian/Hawaiian phases that deposited agglutinated spatter around the vents along with massive-to-bedded unconsolidated scoria and lapilli. Some volcanoes lack evidence for magmatic explosive activity, while others lack evidence for the initial phreatomagmatic phase. During most eruptions, the final activity was the effusion of lava flows that in some cases deformed (or partially destroyed) the volcanic edifices. The erupted volumes varied greatly from one episode to other, without showing any pattern: the highest volumes are recorded in deposits from the third pulse (1060 ka). The volcanoes are located close to faults and always on their footwall blocks, and it is inferred that the regional tectonic stress regime controlled both the timing and spacing of volcanic activity in the volcanic field.

Granular activated carbon pilot treatment studies for explosives removal from contaminated groundwater

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wujcik, W.J.; Lowe, W.L.; Marks, P.J.

1992-08-01

Manufacturing activities at Army Ammunition Plants (AAPs) result in the production of organic wastewaters that contain both explosive residues and other organic chemicals. As a result of past waste practices at such plants, explosive residues may leach through the soil and contaminate groundwater. Two pilot studies were performed to evaluate the use of granular activated carbon (GAC) to treat groundwater contaminated with explosives at Badger AAP and Milan AAP. An additional goal of the Badger AAP study was to examine the potential discharge of explosives 2,4-DNT and 2,6-DNT from a packed column air stripper used to remove volatile organic compoundsmore » from groundwater. A laboratory method was developed for the BAAP study to permit lower detection levels for 2,4-DNT and 2,6-DNT (0.46[mu]g/L and 0.017 [mu]g/L, respectively). The studies concluded that removal of explosives from groundwater using continuous flow GAC is feasible. 14 refs., 10 figs., 11 tabs.« less

Installation-Restoration Program environmental-technology development. Task order 3. Use of activated carbon for treatment of explosives-contaminated ground water at the Badger Army Ammunition Plant (BAAP). Final report Jun 88-Aug 89

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wujcik, W.J.; Lowe, W.L.; Marks, P.J.

1989-08-01

The United States Army operates explosives manufacturing plants to produce various forms of explosives used in military ordnance. Manufacturing activities at such plants result in the production of organic wastewaters that contain both explosive residues and other organic chemicals. Several treatment technologies have been developed to treat these wastewaters for final discharge. Past waste handling practices at explosives manufacturing plants commonly included the use of the unlined lagoons or pits for containing process wastewaters. As a result of these past practices, some explosives residues may leach through the soil and contaminated groundwater. Therefore, the treatment of contaminated groundwater may bemore » required.« less

Infrasound as a Long Standing Tool for Monitoring Continental Ecuadorean Volcanoes

NASA Astrophysics Data System (ADS)

Ruiz, M. C.; Ortiz, H. D.; Hernandez, S.; Palacios, P.; Anzieta, J. C.

2017-12-01

In the last 10 years, infrasound and seismic methods have been successfully used in the continuous monitoring of eruptive activity at Tunguruhua, Reventador, Sangay and Cotopaxi volcanoes. After a dormant period of 81 years, Tungurahua woke up in 1999 and has since been characterized by vulcanian and strombolian eruptions. Beginning in July 2006, a permanent seismo-infrasonic network with 5 collocated seismic and infrasound sensors was installed through a cooperation with Japan International Cooperation Agency (JICA). It recorded more than 6,000 explosions at Tungurahua with reduced amplitudes larger than 270 Pa at 1 km from the active crater, including 3 explosions greater than 6000 Pa associated with short-lived explosions. Major and long sustained eruptions (July 14-15, 2006; August 16-17, 2006; February 6-8, 2008, May 28, 2010; December 4, 2010; December 3-4, 2011; August 18, 2012) generated seismic and infrasound tremors with complex waveforms. In 2002, Reventador volcano produced the largest eruption in Ecuador in the last century (VEI-4). Since September 2012, alternating periods of strombolian activity and short-lived vulcanian explosions are monitored by seismic and microbarometer sensors located on the south-east border of the caldera rim. Non-steady activity with fluctuations between quiescence and frequent explosions, tremor, and chugging events is recorded. Infrasound of explosions ranges from 75 to 6350 Pa in reduced peak-to-peak amplitudes. Sangay, a remote and very active volcano, is monitored by a broadband seismometer and microbarometer collocated at 8 km from the summit. Active periods during the last few months are characterized by explosion events followed by lava flows and small ash emissions. In March 2016, more than 100 explosions were recorded in a single day. Finally, in 2015 Cotopaxi volcano began its recent eruptive period after 138 years of quiescence. One month after the initiation of its eruptive activity, 76 harmonic infrasound signals with a characteristic 5 sec. period were recorded between September and December 2015 that have been related to outgassing or explosive bubble bursts that excite resonance modes in unfilled craters.

Mid-infrared hyperspectral imaging for the detection of explosive compounds

NASA Astrophysics Data System (ADS)

Ruxton, K.; Robertson, G.; Miller, W.; Malcolm, G. P. A.; Maker, G. T.

2012-10-01

Active hyperspectral imaging is a valuable tool in a wide range of applications. A developing market is the detection and identification of energetic compounds through analysis of the resulting absorption spectrum. This work presents a selection of results from a prototype mid-infrared (MWIR) hyperspectral imaging instrument that has successfully been used for compound detection at a range of standoff distances. Active hyperspectral imaging utilises a broadly tunable laser source to illuminate the scene with light over a range of wavelengths. While there are a number of illumination methods, this work illuminates the scene by raster scanning the laser beam using a pair of galvanometric mirrors. The resulting backscattered light from the scene is collected by the same mirrors and directed and focussed onto a suitable single-point detector, where the image is constructed pixel by pixel. The imaging instrument that was developed in this work is based around a MWIR optical parametric oscillator (OPO) source with broad tunability, operating at 2.6 μm to 3.7 μm. Due to material handling procedures associated with explosive compounds, experimental work was undertaken initially using simulant compounds. A second set of compounds that was tested alongside the simulant compounds is a range of confusion compounds. By having the broad wavelength tunability of the OPO, extended absorption spectra of the compounds could be obtained to aid in compound identification. The prototype imager instrument has successfully been used to record the absorption spectra for a range of compounds from the simulant and confusion sets and current work is now investigating actual explosive compounds. The authors see a very promising outlook for the MWIR hyperspectral imager. From an applications point of view this format of imaging instrument could be used for a range of standoff, improvised explosive device (IED) detection applications and potential incident scene forensic investigation.

The hard start phenomena in hypergolic engines. Volume 5: RCS engine deformation and destruct tests

NASA Technical Reports Server (NTRS)

Miron, Y.; Perlee, H. E.

1974-01-01

Tests were conducted to determine the causes of Apollo Reaction Control (RCS) engine failures. Stainless steel engines constructed for use in the destructive tests are described. The tests conducted during the three phase investigation are discussed. It was determined that the explosive reaction that destroys the RCS engines occurs at the time of engine ignition and is apparently due to either the detonation of the heterogeneous constituents of the rocket engine, consisting primarily of unreacted propellant droplets and vapors, and/or the detonation of explosive materials accumulated on the engine walls from previous pulses. Photographs of the effects of explosions on the simulated RCS engines are provided.

Multispectral Observations of Explosive Gas Emissions from Santiaguito, Guatemala

NASA Astrophysics Data System (ADS)

Carn, S. A.; Watson, M.; Thomas, H.; Rodriguez, L. A.; Campion, R.; Prata, F. J.

2016-12-01

Santiaguito volcano, Guatemala, has been persistently active for decades, producing frequent explosions from its actively growing lava dome. Repeated release of volcanic gases contains information about conduit processes during the cyclical explosions at Santiaguito, but the composition of the gas phase and the amount of volatiles released in each explosion remains poorly constrained. In addition to its persistent activity, Santiaguito offers an exceptional opportunity to investigate lava dome degassing processes since the upper surface of the active lava dome can be viewed from the summit of neighboring Santa Maria. In January 2016 we conducted multi-spectral observations of Santiaguito's explosive eruption plumes and passive degassing from multiple perspectives as part of the first NSF-sponsored `Workshop on Volcanoes' instrument deployment. Gas measurements included open-path Fourier-Transform infrared (OP-FTIR) spectroscopy from the Santa Maria summit, coincident with ultraviolet (UV) and infrared (IR) camera and UV Differential Optical Absorption Spectroscopy (DOAS) from the El Mirador site below Santiaguito's active Caliente lava dome. Using the OP-FTIR in passive mode with the Caliente lava dome as the source of IR radiation, we were able to collect IR spectra at high temporal resolution prior to and during two explosions of Santiaguito on 7-8 January, with volcanic SO2 and H2O emissions detected. UV and IR camera data provide constraints on the total SO2 burden in the emissions (and potentially the volcanic ash burden), which coupled with the FTIR gas ratios provides new constraints on the mass and composition of volatiles driving explosions at Santiaguito. All gas measurements indicate significant volatile release during explosions with limited degassing during repose periods. In this presentation we will present ongoing analysis of the unique Santiaguito gas dataset including estimation of the total volatile mass released in explosions and an intercomparison of SO2 amounts recorded by the UV and IR instruments.

Identification of Groundwater Nitrate Contamination from Explosives Used in Road Construction: Isotopic, Chemical, and Hydrologic Evidence.

PubMed

Degnan, James R; Böhlke, J K; Pelham, Krystle; Langlais, David M; Walsh, Gregory J

2016-01-19

Explosives used in construction have been implicated as sources of NO3(-) contamination in groundwater, but direct forensic evidence is limited. Identification of blasting-related NO3(-) can be complicated by other NO3(-) sources, including agriculture and wastewater disposal, and by hydrogeologic factors affecting NO3(-) transport and stability. Here we describe a study that used hydrogeology, chemistry, stable isotopes, and mass balance calculations to evaluate groundwater NO3(-) sources and transport in areas surrounding a highway construction site with documented blasting in New Hampshire. Results indicate various groundwater responses to contamination: (1) rapid breakthrough and flushing of synthetic NO3(-) (low δ(15)N, high δ(18)O) from dissolution of unexploded NH4NO3 blasting agents in oxic groundwater; (2) delayed and reduced breakthrough of synthetic NO3(-) subjected to partial denitrification (high δ(15)N, high δ(18)O); (3) relatively persistent concentrations of blasting-related biogenic NO3(-) derived from nitrification of NH4(+) (low δ(15)N, low δ(18)O); and (4) stable but spatially variable biogenic NO3(-) concentrations, consistent with recharge from septic systems (high δ(15)N, low δ(18)O), variably affected by denitrification. Source characteristics of denitrified samples were reconstructed from dissolved-gas data (Ar, N2) and isotopic fractionation trends associated with denitrification (Δδ(15)N/Δδ(18)O ≈ 1.31). Methods and data from this study are expected to be applicable in studies of other aquifers affected by explosives used in construction.

Design and fabrication of optical chemical sensor for detection of nitroaromatic explosives based on fluorescence quenching of phenol red immobilized poly(vinyl alcohol) membrane.

PubMed

Zarei, Ali Reza; Ghazanchayi, Behnam

2016-04-01

The present study developed a new optical chemical sensor for detection of nitroaromatic explosives in liquid phase. The method is based on the fluorescence quenching of phenol red as fluorophore in a poly(vinyl alcohol) (PVA) membrane in the presence of nitroaromatic explosives as quenchers, e.g., 2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene (2,4-DNT), 4-nitrotoluene (4-NT), 2,4,6-trinitrobenzene (TNB), and nitrobenzene (NB). For chemical immobilization of phenol red in PVA, phenol red reacted with formaldehyde to produce hydroxymethyl groups and then attached to PVA membrane through the hydroxymethyl groups. The optical sensor showed strong quenching of nitroaromatic explosives. A Stern-Volmer graph for each explosive was constructed and showed that the range of concentration from 5.0 × 10(-6) to 2.5 × 10(-4) mol L(-1) was linear for each explosive and sensitivity varied as TNB >TNT>2,4-DNT>NB>4-NT. The response time of the sensor was within 1 min. The proposed sensor showed good reversibility and reproducibility. Copyright © 2015 Elsevier B.V. All rights reserved.

An experimental study of an explosively driven flat plate launcher

NASA Astrophysics Data System (ADS)

Rae, Philip; Haroz, Erik; Armstrong, Chris; Perry, Lee; M Division Team

2017-06-01

For some upcoming experiments it is desired to impact a large explosive assembly with one or more moderate diameter flat metal plates traveling at high velocity (2-3 km s-1). The time of arrival of these plates will need to carefully controlled and delayed (i.e. the time(s) of arrival known to approximately a microsecond). For this reason, producing a flyer plate from more traditional gun assemblies is not possible. Previous researchers have demonstrated the ability to throw reasonably flat metal flyers from the so-called Forest flyer geometry. The defining characteristics of this design are a carefully controlled reduction in explosive area from a larger explosive plane-wave-lens and booster pad to a smaller flyer plate to improve the planarity of the drive available and an air gap between the explosive booster and the plate to reduce the peak tensile stresses generated in the plate to suppress spalling. This experimental series comprised a number of different design variants and plate and explosive drive materials. The aim was to calibrate a predictive computational modeling capability on this kind of system in preparation for later more radical design ideas best tested in a computer before undertaking the expensive business of construction.

Energy transfer through a multi-layer liner for shaped charges

DOEpatents

Skolnick, Saul; Goodman, Albert

1985-01-01

This invention relates to the determination of parameters for selecting materials for use as liners in shaped charges to transfer the greatest amount of energy to the explosive jet. Multi-layer liners constructed of metal in shaped charges for oil well perforators or other applications are selected in accordance with the invention to maximize the penetrating effect of the explosive jet by reference to four parameters: (1) Adjusting the explosive charge to liner mass ratio to achieve a balance between the amount of explosive used in a shaped charge and the areal density of the liner material; (2) Adjusting the ductility of each layer of a multi-layer liner to enhance the formation of a longer energy jet; (3) Buffering the intermediate layers of a multi-layer liner by varying the properties of each layer, e.g., composition, thickness, ductility, acoustic impedance and areal density, to protect the final inside layer of high density material from shattering upon impact of the explosive force and, instead, flow smoothly into a jet; and (4) Adjusting the impedance of the layers in a liner to enhance the transmission and reduce the reflection of explosive energy across the interface between layers.

Estimating explosion properties of normal hydrogen-rich core-collapse supernovae

NASA Astrophysics Data System (ADS)

Pejcha, Ondrej

2017-08-01

Recent parameterized 1D explosion models of hundreds of core-collapse supernova progenitors suggest that success and failure are intertwined in a complex pattern that is not a simple function of the progenitor initial mass. This rugged landscape is present also in other explosion properties, allowing for quantitative tests of the neutrino mechanism from observations of hundreds of supernovae discovered every year. We present a new self-consistent and versatile method that derives photospheric radius and temperature variations of normal hydrogen-rich core-collapse supernovae based on their photometric measurements and expansion velocities. We construct SED and bolometric light curves, determine explosion energies, ejecta and nickel masses while taking into account all uncertainties and covariances of the model. We describe the efforts to compare the inferences to the predictions of the neutrino mechanim. The model can be adapted to include more physical assumptions to utilize primarily photometric data coming from surveys such as LSST.

Explosive east coast cyclogenesis over the west-central North Atlantic Ocean - A composite study derived from ECMWF operational analyses

NASA Technical Reports Server (NTRS)

Manobianco, John

1989-01-01

This paper describes the observational aspects of explosive east-coast cyclogenesis using composites constructed from the daily global analyses generated and archived by ECMWF. An explosively deepening storm or bomb is defined as an extratropical cyclone whose mean sea-level pressure falls at least 1 mb/h for 24 h. The ECMWF data sets are used to examine the three-dimensional kinematic and thermodynamic structure of bombs over the entire depth of the troposphere. The evolution and structure of the composite bomb is diagnosed using a moving coordinate system consisting of a box with dimensions of 35 x 35 deg of latitude-longitude. The results reveal that explosive cyclogenesis is a baroclinic phenomenon in which the rapid development in the presence of strong upper tropospheric forcing is most likely enhanced by a highly destabilized lower troposphere.

Damage Detection of a Concrete Column Subject to Blast Loads Using Embedded Piezoceramic Transducers.

PubMed

Xu, Kai; Deng, Qingshan; Cai, Lujun; Ho, Siuchun; Song, Gangbing

2018-04-28

Some of the most severe structural loadings come in the form of blast loads, which may be caused by severe accidents or even terrorist activities. Most commonly after exposure to explosive forces, a structure will suffer from different degrees of damage, and even progress towards a state of collapse. Therefore, damage detection of a structure subject to explosive loads is of importance. This paper proposes a new approach to damage detection of a concrete column structure subjected to blast loads using embedded piezoceramic smart aggregates (SAs). Since the sensors are embedded in the structure, the proposed active-sensing based approach is more sensitive to internal or through cracks than surface damage. In the active sensing approach, the embedded SAs act as actuators and sensors, that can respectively generate and detect stress waves. If the stress wave propagates across a crack, the energy of the wave attenuates, and the reduction of the energy compared to the healthy baseline is indicative of a damage. With a damage index matrix constructed by signals obtained from an array of SAs, cracks caused by blast loads can be detected throughout the structure. Conventional sensing methods such as the measurement of dynamic strain and acceleration were included in the experiment. Since columns are critical elements needed to prevent structural collapse, knowledge of their integrity and damage conditions is essential for safety after exposure to blast loads. In this research, a concrete column with embedded SAs was chosen as the specimen, and a series of explosive tests were conducted on the column. Experimental results reveal that surface damages, though appear severe, cause minor changes in the damage index, and through cracks result in significant increase of the damage index, demonstrating the effectiveness of the active sensing, enabled by embedded SAs, in damage monitoring of the column under blast loads, and thus providing a reliable indication of structural integrity in the event of blast loads.

Damage Detection of a Concrete Column Subject to Blast Loads Using Embedded Piezoceramic Transducers

PubMed Central

Deng, Qingshan; Cai, Lujun; Ho, Siuchun; Song, Gangbing

2018-01-01

Some of the most severe structural loadings come in the form of blast loads, which may be caused by severe accidents or even terrorist activities. Most commonly after exposure to explosive forces, a structure will suffer from different degrees of damage, and even progress towards a state of collapse. Therefore, damage detection of a structure subject to explosive loads is of importance. This paper proposes a new approach to damage detection of a concrete column structure subjected to blast loads using embedded piezoceramic smart aggregates (SAs). Since the sensors are embedded in the structure, the proposed active-sensing based approach is more sensitive to internal or through cracks than surface damage. In the active sensing approach, the embedded SAs act as actuators and sensors, that can respectively generate and detect stress waves. If the stress wave propagates across a crack, the energy of the wave attenuates, and the reduction of the energy compared to the healthy baseline is indicative of a damage. With a damage index matrix constructed by signals obtained from an array of SAs, cracks caused by blast loads can be detected throughout the structure. Conventional sensing methods such as the measurement of dynamic strain and acceleration were included in the experiment. Since columns are critical elements needed to prevent structural collapse, knowledge of their integrity and damage conditions is essential for safety after exposure to blast loads. In this research, a concrete column with embedded SAs was chosen as the specimen, and a series of explosive tests were conducted on the column. Experimental results reveal that surface damages, though appear severe, cause minor changes in the damage index, and through cracks result in significant increase of the damage index, demonstrating the effectiveness of the active sensing, enabled by embedded SAs, in damage monitoring of the column under blast loads, and thus providing a reliable indication of structural integrity in the event of blast loads. PMID:29710807

Operation CASTLE. Report of the Manager Santa Fe Operations. Extracted Version.

DTIC Science & Technology

Nuclear explosion testing, *Test facilities, *Management planning and control, Pacific Ocean, Eniwetok Atoll, Bikini Atoll, Marshall Islands , Organizations, Construction, Operation, Management, Logistics support, Costs

75 FR 5575 - Taking and Importing Marine Mammals; Navy Training Activities Conducted in the Gulf of Alaska

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-03

... present in the area to sound from various active tactical sonar sources or to pressure from underwater... utilizing mid- and high frequency active sonar sources and explosive detonations. These sonar and explosive...

Feasibility of culvert IED detection using thermal neutron activation

NASA Astrophysics Data System (ADS)

Faust, Anthony A.; McFee, John E.; Clifford, Edward T. H.; Andrews, Hugh Robert; Mosquera, Cristian; Roberts, William C.

2012-06-01

Bulk explosives hidden in culverts pose a serious threat to the Canadian and allied armies. Culverts provide an opportunity to conceal insurgent activity, avoid the need for detectable surface disturbances, and limit the applicability of conventional sub-surface sensing techniques. Further, in spite of the large masses of explosives that can be employed, the large sensor{target separation makes detection of the bulk explosive content challeng- ing. Defence R&D Canada { Sueld and Bubble Technology Industries have been developing thermal neutron activation (TNA) sensors for detection of buried bulk explosives for over 15 years. The next generation TNA sensor, known as TNA2, incorporates a number of improvements that allow for increased sensor-to-target dis- tances, making it potentially feasible to detect large improvised explosive devices (IEDs) in culverts using TNA. Experiments to determine the ability of TNA2 to detect improvised explosive devices in culverts are described, and the resulting signal levels observed for relevant quantities of explosives are presented. Observations conrm that bulk explosives detection using TNA against a culvert-IED is possible, with large charges posing a detection challenge at least as dicult as that of a deeply buried anti-tank landmine. Because of the prototype nature of the TNA sensor used, it is not yet possible to make denitive statements about the absolute sensitivity or detection time. Further investigation is warranted.

A Study of a QCM Sensor Based on TiO₂ Nanostructures for the Detection of NO₂ and Explosives Vapours in Air.

PubMed

Procek, Marcin; Stolarczyk, Agnieszka; Pustelny, Tadeusz; Maciak, Erwin

2015-04-22

The paper deals with investigations concerning the construction of sensors based on a quartz crystal microbalance (QCM) containing a TiO2 nanostructures sensor layer. A chemical method of synthesizing these nanostructures is presented. The prepared prototype of the QCM sensing system, as well as the results of tests for detecting low NO2 concentrations in an atmosphere of synthetic air have been described. The constructed NO2 sensors operate at room temperature, which is a great advantage, because resistance sensors based on wide gap semiconductors often require much higher operation temperatures, sometimes as high as 500 °C. The sensors constructed by the authors can be used, among other applications, in medical and chemical diagnostics, and also for the purpose of detecting explosive vapours. Reactions of the sensor to nitroglycerine vapours are presented as an example of its application. The influence of humidity on the operation of the sensor was studied.

A Study of a QCM Sensor Based on TiO2 Nanostructures for the Detection of NO2 and Explosives Vapours in Air

PubMed Central

Procek, Marcin; Stolarczyk, Agnieszka; Pustelny, Tadeusz; Maciak, Erwin

2015-01-01

The paper deals with investigations concerning the construction of sensors based on a quartz crystal microbalance (QCM) containing a TiO2 nanostructures sensor layer. A chemical method of synthesizing these nanostructures is presented. The prepared prototype of the QCM sensing system, as well as the results of tests for detecting low NO2 concentrations in an atmosphere of synthetic air have been described. The constructed NO2 sensors operate at room temperature, which is a great advantage, because resistance sensors based on wide gap semiconductors often require much higher operation temperatures, sometimes as high as 500 °C. The sensors constructed by the authors can be used, among other applications, in medical and chemical diagnostics, and also for the purpose of detecting explosive vapours. Reactions of the sensor to nitroglycerine vapours are presented as an example of its application. The influence of humidity on the operation of the sensor was studied. PMID:25912352

Seismicity and infrasound associated with explosions at Mount St. Helens, 2004-2005: Chapter 6 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

USGS Publications Warehouse

Moran, Seth C.; McChesney, Patrick J.; Lockhart, Andrew B.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

2008-01-01

Six explosions occurred during 2004-5 in association with renewed eruptive activity at Mount St. Helens, Washington. Of four explosions in October 2004, none had precursory seismicity and two had explosion-related seismic tremor that marked the end of the explosion. However, seismicity levels dropped following each of the October explosions, providing the primary instrumental means for explosion detection during the initial vent-clearing phase. In contrast, explosions on January 16 and March 8, 2005, produced noticeable seismicity in the form of explosion-related tremor, infrasonic signals, and, in the case of the March 8 explosion, an increase in event size ~2 hours before the explosion. In both 2005 cases seismic tremor appeared before any infrasonic signals and was best recorded on stations located within the crater. These explosions demonstrated that reliable explosion detection at volcanoes like Mount St. Helens requires seismic stations within 1-2 km of the vent and stations with multiple acoustic sensors.

Volcano Inflation prior to Gas Explosions at Semeru Volcano, Indonesia

NASA Astrophysics Data System (ADS)

Nishimura, T.; Iguchi, M.; Kawaguchi, R.; Surono, S.; Hendrasto, M.; Rosadi, U.

2010-12-01

Semeru volcano in east Java, Indonesia, is well known to exhibit small vulcanian eruptions at the summit crater. Such eruptive activity stopped on April 2009, but volcanic earthquakes started to occur in August and a lava dome was found in the summit crater on November. Since then, lava sometimes flows downward on the slope and small explosions emitting steams from active crater frequently occur every a few to a few tens of minutes. Since the explosions repeatedly occur with short intervals and the active crater is located close to the summit with an altitude of 3676m, the explosions are considered to originate from the gas (steams) from magma itself in the conduit and not to be caused by interactions of magma with the underground water. We installed a tiltmeter at the summit on March 2010 to study the volcanic eruption mechanisms. The tiltmeter (Pinnacle hybrid type, accuracy of measurement is 1 nrad ) was set at a depth of about 1 m around the summit about 500 m north from the active crater. The data stored every 1 s in the internal memory was uploaded every 6 hours by a small data logger with GPS time correction function. More than one thousand gas explosion events were observed for about 2 weeks. We analyze the tilt records as well as seismic signals recorded at stations of CVGHM, Indonesia. The tilt records clearly show uplift of the summit about 20 to 30 seconds before each explosion. Uplifts before large explosions reach to about 20 - 30 n rad, which is almost equivalent to the volume increase of about 100 m^3 beneath the crater. To examine the eruption magnitude dependence on the uplift, we classify the eruptions into five groups based on the amplitudes of seismograms associated with explosions. We stack the tilt records for these groups to reduce noises in the signals and to get general characteristics of the volcano inflations. The results show that the amplitudes of uplifts are almost proportional to the amplitudes of explosion earthquakes while the preceding time of uplift is almost constant (20 s - 30 s). This implies that the inflation rate controls the magnitude of gas explosions. The observed preceding time of inflation prior to gas explosions are much shorter than those for the inflations before magmatic explosions (Nishi et al., 2007; Iguchi et al., 2008), which suggests that the pressurization processes in shallow conduit for gas explosions are different from that for explosions emitting ashes.

76 FR 56224 - Agency Information Collection Activities; Proposed Collection, Comments Requested: Records and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-12

..., and Users Licensed Under Title 18 U.S.C. Chapter 40 Explosives ACTION: 30-Day Notice of Information... Disposition By Explosives Importers, Manufacturers, Dealers, and Users Licensed Under Title 18 U.S.C... under 18 U.S.C. chapter 40 Explosives. The records are used to show where and to whom explosive...

49 CFR 176.137 - Portable magazine.

Code of Federal Regulations, 2010 CFR

2010-10-01

... requirements: (1) It must be weather-tight, constructed of wood or metal lined with wood at least 2 cm (0.787... wood, a portable magazine must be framed of nominal 5 cm × 10 cm (2×4 inch) lumber, and sheathed with... used for the stowage of Class 1 (explosive) materials under such construction, handling, and stowage...

46 CFR 160.038-3 - Materials, workmanship, and construction.

Code of Federal Regulations, 2011 CFR

2011-10-01

... of the metal chest and fittings shall be given a heavy coat of quick drying red lead, zinc chromate... be constructed of metal and lined with wood. (b) The lining shall be so fitted and finished as to... explosives or pyrotechnics from contact with metal surfaces. (c) The metal shall be 1/8 inch thick and free...

46 CFR 160.038-3 - Materials, workmanship, and construction.

Code of Federal Regulations, 2013 CFR

2013-10-01

... of the metal chest and fittings shall be given a heavy coat of quick drying red lead, zinc chromate... be constructed of metal and lined with wood. (b) The lining shall be so fitted and finished as to... explosives or pyrotechnics from contact with metal surfaces. (c) The metal shall be 1/8 inch thick and free...

46 CFR 160.038-3 - Materials, workmanship, and construction.

Code of Federal Regulations, 2010 CFR

2010-10-01

... of the metal chest and fittings shall be given a heavy coat of quick drying red lead, zinc chromate... be constructed of metal and lined with wood. (b) The lining shall be so fitted and finished as to... explosives or pyrotechnics from contact with metal surfaces. (c) The metal shall be 1/8 inch thick and free...

46 CFR 160.038-3 - Materials, workmanship, and construction.

Code of Federal Regulations, 2012 CFR

2012-10-01

... of the metal chest and fittings shall be given a heavy coat of quick drying red lead, zinc chromate... be constructed of metal and lined with wood. (b) The lining shall be so fitted and finished as to... explosives or pyrotechnics from contact with metal surfaces. (c) The metal shall be 1/8 inch thick and free...

46 CFR 160.038-3 - Materials, workmanship, and construction.

Code of Federal Regulations, 2014 CFR

2014-10-01

... of the metal chest and fittings shall be given a heavy coat of quick drying red lead, zinc chromate... be constructed of metal and lined with wood. (b) The lining shall be so fitted and finished as to... explosives or pyrotechnics from contact with metal surfaces. (c) The metal shall be 1/8 inch thick and free...

Defense Small Business Innovation Research Program (SBIR). Volume 1. Army Abstracts of Phase 1 Awards from FY 1988 SBIR Solicitation

DTIC Science & Technology

1989-05-01

CONSTRUCTION). CONCEPT ANALYSIS CORP 14789 KEEL ST PLYMOUTH, MI 48170 CONTRACT NUMBER: DAHO -88-C-0942 DR’S WALDEN & GLANCE TITLE: MISSILE GEOMETRY PACKAGE TOPIC...COUNTING STUDY CAN BE UTILIZED TO EVALUATE THE EFFECTIVENESS OF AN EXPLOSION MONITORING SYSTEM. E SMALL BUSINESS INNOVATION RESEARCH (SBIR) PROGRAM - PHASE... EXPLOSIVE OR GROUND PENETRATING MUNITIONS ARE TO BE EVALUATED. IN THAT CASE THE SYSTEM WILL BE ENHANCED WITH SEISMIC SENSORS. THE SEISMIC SIGNALS MAY

Experimental transient and permanent deformation studies of steel-sphere-impacted or explosively-impulsed aluminum panels

NASA Technical Reports Server (NTRS)

Witmer, E. A.; Merlis, F.; Rodal, J. J. A.; Stagliano, T. R.

1977-01-01

The sheet explosive loading technique (SELT) was employed to obtain elastic-plastic, large deflection 3-d transient and/or permanent strain data on simple well defined structural specimens and materials: initially-flat 6061-T651 aluminum panels with all four sides ideally clamped via integral construction. The SELT loading technique was chosen since it is both convenient and provides "forcing function information" of small uncertainty. These data will be useful for evaluating pertinent 3-d structural response prediction methods.

Pilot-scale steam explosion for xylose production from oil palm empty fruit bunches and the use of xylose for ethanol production.

PubMed

Duangwang, Sairudee; Ruengpeerakul, Taweesak; Cheirsilp, Benjamas; Yamsaengsung, Ram; Sangwichien, Chayanoot

2016-03-01

Pilot-scale steam explosion equipments were designed and constructed, to experimentally solubilize xylose from oil palm empty fruit bunches (OPEFB) and also to enhance an enzyme accessibility of the residual cellulose pulp. The OPEFB was chemically pretreated prior to steam explosion at saturated steam (SS) and superheated steam (SHS) conditions. The acid pretreated OPEFB gave the highest xylose recovery of 87.58 ± 0.21 g/kg dried OPEFB in the liquid fraction after explosion at SHS condition. These conditions also gave the residual cellulose pulp with high enzymatic accessibility of 73.54 ± 0.41%, which is approximately threefold that of untreated OPEFB. This study has shown that the acid pretreatment prior to SHS explosion is an effective method to enhance both xylose extraction and enzyme accessibility of the exploded OPEFB. Moreover, the xylose solution obtained in this manner could directly be fermented by Candida shehatae TISTR 5843 giving high ethanol yield of 0.30 ± 0.08 g/g xylose. Copyright © 2015 Elsevier Ltd. All rights reserved.

30 CFR 18.38 - Leads through common walls.

Code of Federal Regulations, 2014 CFR

2014-07-01

... APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design... from one explosion-proof enclosure to another through conduit, tubing, piping, or other solid-wall...

30 CFR 18.38 - Leads through common walls.

Code of Federal Regulations, 2013 CFR

2013-07-01

... APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design... from one explosion-proof enclosure to another through conduit, tubing, piping, or other solid-wall...

30 CFR 18.38 - Leads through common walls.

Code of Federal Regulations, 2011 CFR

2011-07-01

... APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design... from one explosion-proof enclosure to another through conduit, tubing, piping, or other solid-wall...

30 CFR 18.38 - Leads through common walls.

Code of Federal Regulations, 2012 CFR

2012-07-01

... APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design... from one explosion-proof enclosure to another through conduit, tubing, piping, or other solid-wall...

Parameterization of strombolian explosions: constraint from simultaneous physical and geophysical measurements (Invited)

NASA Astrophysics Data System (ADS)

gurioli, L.; Harris, A. J.

2013-12-01

Strombolian activity is the most common type of explosive eruption (by frequency) experienced by Earth's volcanoes. It is commonly viewed as consisting of a succession of short discrete explosions where fragments of incandescent magma are ejected a few tens to hundreds meters into the air. This kind of activity is generally restricted to basaltic or basaltic-andesitic magmas because these systems have the sufficiently low viscosities so as to allow gas coalescence and decoupled slug ascent. Mercalli (1907) proposed one of the first formal classifications of explosive activity based on the character of the erupted products and descriptions of case-type eruptions. Later, Walker (1973) devised a classification based on grain size and dispersion, within which strombolian explosions formed the low-to-middle end of the classification. Other classifications have categorized strombolian activity on the basis of erupted magnitude and/or intensity, such as Newhall and Self's (1982) Volcanic Explosivity Index (VEI). Classification can also be made on the basis of explosion mechanism, where strombolian eruptions have become associated with bursting of large gas bubbles, as opposed to release of locked in bubble populations in rapidly ascending magma that feed sustained fountains. Finally, strombolian eruptions can be defined on the basis of geophysical metrics for the explosion source and plume ascent dynamics. Recently, the volcanology community has begun to discuss the difficulty of actually placing strombolian explosions within the compartments defined by each scheme. New sampling strategies in active strombolian volcanic fields have allowed us to parameterize these mildly explosive events both physically and geophysically. Our data show that individual 'normal' and "major" explosions at Stromboli are extremely small, meaning that the classical deposit-based classification thresholds need to be reduced, or a new category defined, if the 'strombolian' eruption style at Stromboli, and other volcanoes like it, are to plot in the strombolian fields of deposit-based classifications. We also quenched a number of bombs soon explosion at Stromboli. This enabled us to quantify the degassing history and rheology of the magma(s) resident in the shallow, near-surface, system. The different textural facies observed in these bombs showed that fresh magma, mingled with partially or completely degassed, oxidized, re-crystallized, evolved and high viscosity magma, was ejected. The degassed magma appears to sit at the top of the conduit, playing only a passive role in the explosive process. Our best model, is that the degassed, oxidized magma forms a plug, or rheologically defined layer, at the top of the conduit, through which the fresh magma bursts. Integration of geophysical measurements with sample analyses, indicates that popular (bubble-bursting) models may not fit this case, thus also changeling the model-based definition of this eruption type.

Aspherical Supernovae and Oblique Shock Breakout

NASA Astrophysics Data System (ADS)

Afsariardchi, Niloufar; Matzner, Christopher D.

2017-02-01

In an aspherical supernova explosion, shock emergence is not simultaneous and non-radial flows develop near the stellar surface. Oblique shock breakouts tend to be easily developed in compact progenitors like stripped-envelop core collapse supernovae. According to Matzner et al. (2013), non-spherical explosions develop non-radial flows that alters the observable emission and radiation of a supernova explosion. These flows can limit ejecta speed, change the distribution of matter and heat of the ejecta, suppress the breakout flash, and most importantly engender collisions outside the star. We construct a global numerical FLASH hydrodynamic simulation in a two dimensional spherical coordinate, focusing on the non-relativistic, adiabatic limit in a polytropic envelope to see how these fundamental differences affect the early light curve of core-collapse SNe.

Biotransformation of explosives by Reticulitermes flavipes--associated termite Endosymbionts.

PubMed

Indest, Karl J; Eaton, Hillary L; Jung, Carina M; Lounds, Caly B

2014-01-01

Termites have an important role in the carbon and nitrogen cycles despite their reputation as destructive pests. With the assistance of microbial endosymbionts, termites are responsible for the conversion of complex biopolymers into simple carbon substrates. Termites also rely on endosymbionts for fixing and recycling nitrogen. As a result, we hypothesize that termite bacterial endosymbionts are a novel source of metabolic pathways for the transformation of nitrogen-rich compounds like explosives. Explosives transformation capability of termite (Reticulitermes flavipes)-derived endosymbionts was determined in media containing the chemical constituents nitrotriazolone (NTO) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) that comprise new insensitive explosive formulations. Media dosed with 40 µg/ml of explosive was inoculated with surface-sterilized, macerated termites. Bacterial isolates capable of explosives transformation were characterized by 16S rRNA sequencing. Termite-derived enrichment cultures demonstrated degradation activity towards the explosives NTO, RDX, as well as the legacy explosive 2,4,6-trinitrotoluene (TNT). Three isolates with high similarity to the Enterobacteriaceae(Enterobacter, Klebsiella) were able to transform TNT and NTO within 2 days, while isolates with high similarity to Serratia marcescens and Lactococcus lactis were able to transform RDX. Termite endosymbionts harbor a range of metabolic activities and possess unique abilities to transform nitrogen-rich explosives. © 2014 S. Karger AG, Basel.

Multilateral haptics-based immersive teleoperation for improvised explosive device disposal

NASA Astrophysics Data System (ADS)

Erickson, David; Lacheray, Hervé; Daly, John

2013-05-01

Of great interest to police and military organizations is the development of effective improvised explosive device (IED) disposal (IEDD) technology to aid in activities such as mine field clearing, and bomb disposal. At the same time minimizing risk to personnel. This paper presents new results in the research and development of a next generation mobile immersive teleoperated explosive ordnance disposal system. This system incorporates elements of 3D vision, multilateral teleoperation for high transparency haptic feedback, immersive augmented reality operator control interfaces, and a realistic hardware-in-the-loop (HIL) 3D simulation environment incorporating vehicle and manipulator dynamics for both operator training and algorithm development. In the past year, new algorithms have been developed to facilitate incorporating commercial off-the-shelf (COTS) robotic hardware into the teleoperation system. In particular, a real-time numerical inverse position kinematics algorithm that can be applied to a wide range of manipulators has been implemented, an inertial measurement unit (IMU) attitude stabilization system for manipulators has been developed and experimentally validated, and a voice­operated manipulator control system has been developed and integrated into the operator control station. The integration of these components into a vehicle simulation environment with half-car vehicle dynamics has also been successfully carried out. A physical half-car plant is currently being constructed for HIL integration with the simulation environment.

46 CFR 194.05-7 - Explosives-Detail requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... shall be constructed of incombustible materials; awnings and tarpaulins shall be fire-resistant and/or flame proof fabric. (3) Items shall be properly secured by using existing vessel structures such as...

Identification of groundwater nitrate contamination from explosives used in road construction: Isotopic, chemical, and hydrologic evidence

USGS Publications Warehouse

Degnan, James R.; Böhlke, John Karl; Pelham, Krystle; David M. Langlais,; Walsh, Gregory J.

2015-01-01

Explosives used in construction have been implicated as sources of NO3– contamination in groundwater, but direct forensic evidence is limited. Identification of blasting-related NO3– can be complicated by other NO3– sources, including agriculture and wastewater disposal, and by hydrogeologic factors affecting NO3– transport and stability. Here we describe a study that used hydrogeology, chemistry, stable isotopes, and mass balance calculations to evaluate groundwater NO3– sources and transport in areas surrounding a highway construction site with documented blasting in New Hampshire. Results indicate various groundwater responses to contamination: (1) rapid breakthrough and flushing of synthetic NO3– (low δ15N, high δ18O) from dissolution of unexploded NH4NO3 blasting agents in oxic groundwater; (2) delayed and reduced breakthrough of synthetic NO3– subjected to partial denitrification (high δ15N, high δ18O); (3) relatively persistent concentrations of blasting-related biogenic NO3– derived from nitrification of NH4+ (low δ15N, low δ18O); and (4) stable but spatially variable biogenic NO3– concentrations, consistent with recharge from septic systems (high δ15N, low δ18O), variably affected by denitrification. Source characteristics of denitrified samples were reconstructed from dissolved-gas data (Ar, N2) and isotopic fractionation trends associated with denitrification (Δδ15N/Δδ18O ≈ 1.31). Methods and data from this study are expected to be applicable in studies of other aquifers affected by explosives used in construction.

Explosions within a Deep Crater: Detection from Land and Space

NASA Astrophysics Data System (ADS)

Worden, A. K.; Dehn, J.; De Angelis, S.

2012-12-01

Many volcanoes in the North Pacific exhibit small scale explosive activity. This activity is typified by small explosions throwing ash, blocks, and spatter out of a central vent located within a crater. This material can be thrown out onto the flanks of the volcano if the vent is near enough to the crater rim. However, at some volcanoes, the vent is tens to hundreds of meters below the crater rim. The crater walls constrain the erupted material, causing it to fall back into the vent. Infill of material clogs the vent and can cause future explosions to become muffled. The depth of the crater also inhibits clear views of the vent for satellite remote sensing. In order for a satellite to record an image of a very deep vent, it requires very near vertical pass angle (satellite zenith angle). This viewing geometry is rare, meaning that the majority of images at such volcanoes will show the flanks or the crater walls, not the actual vent or crater floor. A method was developed for using satellite data to monitor the frequency of small explosive activity at numerous volcanoes. By determining the frequency of small explosions seen as thermal features in satellite imagery, a baseline of activity was determined. Any changes from this baseline are then used to indicate possible changes in the volcanic system or eruptive activity of the volcano. This method was used on data collected at Mt. Chuginadak (Cleveland) in Alaska, Karymsky Volcano in Russia, and Stromboli Volcano in Italy with good results. The method was then applied to Shishaldin Volcano in Alaska but was not as useful in determining the activity of the volcano due to the depth of Shishaldin's central crater (400m). This highlights the importance of multi-disciplinary and multi-sensor research to determine the actual activity at a volcano. For this project, explosions at Shishaldin Volcano were counted in both satellite data (thermal anomalies) and seismic data (explosion signals) for a time period from 2008-2010. These datasets are then compared to determine if there is a relationship that can be carried through the data, or if there is any other connecting factor to aid in the detection and monitoring of small scale explosive activity at volcanoes with vents deep within a crater. If a distinguishing factor can be verified by looking at a location with both satellite and seismic monitoring, it may aid in the monitoring of volcanoes where land based monitoring is not safe or financially viable.

Multiplets: Their behavior and utility at dacitic and andesitic volcanic centers

USGS Publications Warehouse

Thelen, W.; Malone, S.; West, M.

2011-01-01

Multiplets, or groups of earthquakes with similar waveforms, are commonly observed at volcanoes, particularly those exhibiting unrest. Using triggered seismic data from the 1980-1986 Mount St. Helens (MSH) eruption, we have constructed a catalog of multiplet occurrence. Our analysis reveals that the occurrence of multiplets is related, at least in part, to the viscosity of the magma. We also constructed catalogs of multiplet occurrence using continuous seismic data from the 2004 eruption at MSH and 2007 eruption at Bezymianny Volcano, Russia. Prior to explosions at MSH in 2004 and Bezymianny in 2007, the multiplet proportion of total seismicity (MPTS) declined, while the average amplitudes and standard deviations of the average amplitude increased. The life spans of multiplets (time between the first and last event) were also shorter prior to explosions than during passive lava extrusion. Dome-forming eruptions that include a partially solidified plug, like MSH (1983-1986 and 2004-2008), often possess multiplets with longer life spans and MPTS values exceeding 50%. Conceptually, the relatively unstable environment prior to explosions is characterized by large and variable stress gradients brought about by rapidly changing overpressures within the conduit. We infer that such complex stress fields affect the number of concurrent families, MPTS, average amplitude, and standard deviation of the amplitude of the multiplets. We also argue that multiplet detection may be an important new monitoring tool for determining the timing of explosions and in forecasting the type of eruption.

The effect of explosive percentage on underwater explosion energy release of hexanitrohexaazaisowurtzitane and octogen based aluminized explosives

NASA Astrophysics Data System (ADS)

Jiao, Qingjie; Wang, Qiushi; Nie, Jianxin; Guo, Xueyong; Zhang, Wei; Fan, Wenqi

2018-03-01

To control the explosion energy output by optimizing explosive components is a key requirement in a number of different application areas. The effect of different Al/O Ratio on underwater explosion of aluminized explosives has been studied detailedly. However, the effect of explosive percentage in the same Al/O Ratio is rarely researched, especially for Hexanitrohexaazaisowurtzitane (CL-20) based aluminized explosives. In this study, we performed the underwater explosion experiments with 1.2-kilogram explosives in order to investigate the explosion energy released from CL-20 and Octogen (HMX) based aluminized explosives. The percentage of the explosive varied from 5% to 30% and it is shown that: the shockwave peak pressure (pm) grows gradually; shock wave energy (Es) continues increasing, bubble energy (Eb) increases then decreases peaking at 15% for both formulas, and the total energy (E) and energy release rate (η) peak at 20% for CL-20 and 15% for HMX. This paper outlines the physical mechanism of Eb change under the influence of an aluminium initial reaction temperature and reaction active detonation product percentage coupling. The result shows that CL-20 is superior as a new high explosive and has promising application prospects in the regulation of explosive energy output for underwater explosives.

Evaluation of active and passive near-millimeter-wave radiometric imaging techniques for detection of concealed objects

NASA Astrophysics Data System (ADS)

Reber, E. E.; Foote, F. B.; Schellenbaum, R. L.; Bradley, R. G.

1981-07-01

The potential of radiometric imaging technique to detect shielded nuclear materials and explosives carried covertly by personnel was investigated. This method of detecting contraband depends upon the differences in emissivity and reflectivity of the contraband relative to human tissue. Explosives, unlike metals and metal composites, generally have high emissivities and low reflectivities that closely approximate those of human tissue making explosives difficult to detect. Samples of several common types of explosives (TNT, Detasheet, C4, and several types of water gels) were examined at the 1.4- and 3-mm wavelengths using active and passive radiometeric techniques.

P and S wave Coda Calibration in Central Asia and South Korea

NASA Astrophysics Data System (ADS)

Kim, D.; Mayeda, K.; Gok, R.; Barno, J.; Roman-Nieves, J. I.

2017-12-01

Empirically derived coda source spectra provide unbiased, absolute moment magnitude (Mw) estimates for events that are normally too small for accurate long-period waveform modeling. In this study, we obtain coda-derived source spectra using data from Central Asia (Kyrgyzstan networks - KN and KR, and Tajikistan - TJ) and South Korea (Korea Meteorological Administration, KMA). We used a recently developed coda calibration module of Seismic WaveForm Tool (SWFT). Seismic activities during this recording period include the recent Gyeongju earthquake of Mw=5.3 and its aftershocks, two nuclear explosions from 2009 and 2013 in North Korea, and a small number of construction and mining-related explosions. For calibration, we calculated synthetic coda envelopes for both P and S waves based on a simple analytic expression that fits the observed narrowband filtered envelopes using the method outlined in Mayeda et al. (2003). To provide an absolute scale of the resulting source spectra, path and site corrections are applied using independent spectral constraints (e.g., Mw and stress drop) from three Kyrgyzstan events and the largest events of the Gyeongju sequence in Central Asia and South Korea, respectively. In spite of major tectonic differences, stable source spectra were obtained in both regions. We validated the resulting spectra by comparing the ratio of raw envelopes and source spectra from calibrated envelopes. Spectral shapes of earthquakes and explosions show different patterns in both regions. We also find (1) the source spectra derived from S-coda is more robust than that from the P-coda at low frequencies; (2) unlike earthquake events, the source spectra of explosions have a large disagreement between P and S waves; and (3) similarity is observed between 2016 Gyeongju and 2011 Virginia earthquake sequence in the eastern U.S.

27 CFR 555.142 - Relief from disabilities (effective January 24, 2003).

Code of Federal Regulations, 2014 CFR

2014-04-01

... Discharge from Active Duty (Department of Defense Form 214), Charge Sheet (Department of Defense Form 458... ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES... records, statements and other information concerning employment, medical history, military service...

Explosion probability of unexploded ordnance: expert beliefs.

PubMed

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

2008-08-01

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

Insensitive detonator apparatus for initiating large failure diameter explosives

DOEpatents

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.

Characterization and Thermal Decomposition of Nanometer 2,2', 4,4', 6,6'-Hexanitro-Stilbene and 1,3,5-Triamino-2,4,6-Trinitrobenzene Fabricated by a Mechanical Milling Method

NASA Astrophysics Data System (ADS)

Song, Xiaolan; Wang, Yi; Zhao, Shanshan; An, Chongwei; Wang, Jingyu; Zhang, Jinglin

2018-04-01

Nanometer 2,2', 4,4', 6,6'-hexanitro-stilbene (HNS) and 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) were fabricated on a high-energy ball mill. The particle sizes of nano-HNS and nano-TATB were 98.4 and 57.8 nm, respectively. An SEM analysis was employed to image the micron morphology of nano-explosives. The particle size distribution was calculated by measuring the size of 300 particles in SEM images. XRD, IR, and XPS analyses were used to confirm whether the crystal phase, molecule structure, and surface elements were changed by the milling process. Thermal decomposition of nano-HNS and nano-TATB was investigated by differential scanning calorimetry (DSC) and thermal-infrared spectrometry online (DSC-IR) analyses. Using DSC traces collected from different heating rates, the kinetic and thermodynamic parameters of thermolysis of raw and nano-explosives were calculated (activation energy (EK), pre-exponential factor (lnAK), rate constant (k), activation heat (ΔH≠), activation free energy (ΔG≠), activation entropy (ΔS≠), critical temperature of thermal explosion (Tb), and critical heating rate of thermal explosion (dT/dt)Tb). The results indicated that nano-explosives were of different kinetic and thermodynamic properties from starting explosives. In addition, the gas products for thermal decomposition of nano-HNS and nano-TATB were detected. Although HNS and TATB are both nitro explosives, the decomposition products of the two were different. A mechanism to explain the difference is proposed.

Risk Assessment for the Explosive Washout Lagoons (Site 4), Umatilla Depot Activity Hermiston, Oregon

DTIC Science & Technology

1992-03-01

Activity .............................. 2 2-2 Explosive Washout Lagoons (Site 4) and Washout Plant Area ............................... 2-3 3-1 Site 4...ponds for liquid wastes from bomb-washing operations in the washout plant . The measured dimensions of the flat bottoms of the two lagoons are 30 by 80...explosives washout plant system was drained, flushed, and cleaned approximately once each week from the mid-1950s until 1965. The lagoons received all of the

The activity of the Colima volcano and morphological changes in the summit between 2004 and 2013

NASA Astrophysics Data System (ADS)

Suarez-Plascencia, C.; Nunez-Cornu, F. J.; Camarena Garcia, M. A.

2013-05-01

Colima Volcano, located in the West of the Volcanic Mexican Belt (19° 30.696 N, 103° 37.026 W), has shown a new cycle of explosive activity beginning May 30 1999, and reaching its maximum in March-April of 2005 and January 2013. In the 2005 the explosive activity increased gradually, having the largest event on May 23, when a new dome was created. Hours later this dome was destroyed by a strong explosion, forming an ash column 5.6 km high with subsequent pyroclastic flows that reached a distance of 4.2 km flowing along the ravines of the South sector. On May 30 the most intense explosion in 1999 occurred, when the plume reached heights in excess of 4.4 km above the crater, and pyroclastic flows were created. On the same year in July two explosive events occurred of characteristics similar to those in May. These constant explosions caused continuous morphological changes in the summit, the most significant being the collapse of the North and South walls of the crater, in the first week of June of 2005, and the creation of a new crater in July. In 2006 the most significant explosive activity took place during April, May and July, when the eruptive columns reached heights of more than 1500 meters above the crater, occasionally forming small pyroclastic flows. In May of 2007 morphological changes were observed in the summit. Among them a crater explosion on the East side, a dome was formed on the West side, with 20 m in high and 50 m in diameter. Since the end of 2008 to December of 2012 the volcano remained calm, with a dome diameter of 220 m and height of 60 m, in January 2013 three explosions occurred, destroying the dome and throwing a volume of 1.5 million cubic meters. The eruptive column reached a height of 3000 above the crater. It reported light ashfall to the NE to 100 km away from the volcano. The explosive events continue to date, but they have diminished in size and intensity. This activity was similar to the one observed in 1902-1903 and reported by Severo Diaz and J.M. Arreola (1906), but without reaching the maximum levels of activity reported for 1903, where it had levels of three to five maximum explosive events per day. The photographs and the digital mapping have provided detailed information to quantify the dynamic evolution of the volcanic structures that developed on the summit of the volcano in the course of the last for years. The cartographic and database information obtained will be the basis for updating the Operational Plan of the Colima Volcano by the State Civil & Fire Protection Unit of Jalisco, Mexico, and the urban development plans of surrounding municipalities, in order to reduce their vulnerability to the hazards of the volcanic activity.

Refinement of parameters of weak nuclear explosions conducted at the Semipalatinsk test site on the basis of historical seismograms study

NASA Astrophysics Data System (ADS)

Sokolova, Inna

2014-05-01

Many researchers working in the field of monitoring and discriminating of nuclear tests encounter the problem of lacking in seismic catalogues the information about source parameters for weak nuclear explosions. As usual, the information about origin time, coordinates and magnitude is absent, there is information about date, approximate coordinates and information about explosion yield. Huge work conducted on recovery of parameters of small underground nuclear explosions conducted at the Semipalatinsk Test Site using records of analogue seismic stations of the USSR located at regional distances was conducted by V. Khalturin, T. Rayutian, P. Richards (Pure and Applied Geophysics, 2001). However, if underground nuclear explosions are studied and described in literature quite well, then air and contact explosions were small and were not recorded by standard permanent seismic stations. In 1961-1962 maximum number of air and contact explosions was conducted at Opytnoye polye site of the STS. We managed to find and analyze additional seismic data from some temporary and permanent stations. That time IPE AS USSR installed a network of high-sensitive stations along Pamir-Baykal profile to study earth crust structure and upper mantle, the profile length was 3500 km. Epicentral distance from some stations of the profile to Opytnoye polye was 300-400 km. In addition, a permanent seismic station Semipalatinsk (SEM) located 175 km away from the site started its operation. The seismograms from this station became available recently. The digitized historical seismograms allowed to recover and add parameters for more than 36 air and surface explosions. Origin time, coordinates, magnitudes mpv, MLV and energy class K were determined for explosions. A regional travel-time curve for Central Kazakhstan constructed using records of calibration chemical explosions conducted at the STS in 1997-2000 and ground-truth underground nuclear explosions was used to determine kinematic parameters of explosions. MLV, mpv, and energy class K were determined for all underground nuclear explosions conducted at the STS using historical seismograms from Central Asia stations. Dependencies of regional magnitudes on yield were received for air and underground nuclear explosions. Thus, application of historical seismograms at regional distances allows to recover and replenish the seismic catalogues of past nuclear explosions for further use in scientific investigations and monitoring tasks.

Characterization of plasma sprayed and explosively consolidated simulated lunar soil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Powell, S.J.; Inal, O.T.; Smith, M.F.

1997-06-01

Two methods for the use of lunar materials for the construction of shelters on the Moon are being proposed: explosive consolidation of the soil into structural components and plasma spraying of the soil to join components. The plasma-sprayed coating would also provide protection from the intense radiation. In this work, a mare simulant was plasma-sprayed onto a stainless steel substrate. Deposition of a 0.020 inch coating using power inputs of 23, 25, 27 and 29 kW were compared. Hardness of the coatings increased with each increase of power to the system, while porosity at the interface decreased. All coatings exhibitedmore » good adhesion. Simultaneously, an explosively consolidated sample was similarly characterized to afford a comparison of structural features associated with each mode of proposed use.« less

Fabrication and testing of a standoff trace explosives detection system

NASA Astrophysics Data System (ADS)

Waterbury, Robert; Rose, Jeremy; Vunck, Darius; Blank, Thomas; Pohl, Ken; Ford, Alan; McVay, Troy; Dottery, Ed

2011-05-01

In order to stop the transportation of materials used for IED manufacture, a standoff checkpoint explosives detection system (CPEDS) has recently been fabricated. The system incorporates multi-wavelength Raman spectroscopy and laser induced breakdown spectroscopy (LIBS) modalities with a LIBS enhancement technique called TEPS to be added later into a single unit for trace detection of explosives at military checkpoints. Newly developed spectrometers and other required sensors all integrated with a custom graphical user interface for producing simplified, real-time detection results are also included in the system. All equipment is housed in a military ruggedized shelter for potential deployment intheater for signature collection. Laboratory and performance data, as well as the construction of the CPEDS system and its potential deployment capabilities, will be presented in the current work.

Barberton greenstone belt volcanism: Succession, style and petrogenesis

NASA Technical Reports Server (NTRS)

Byerly, G. R.; Lowe, D. R.

1986-01-01

The Barberton Mountain Land is an early Archean greenstone belt along the eastern margin of the Kaapvaal Craton of southern Africa. Detailed mapping in the southern portion of the belt leads to the conclusion that a substantial thickness is due to original deposition of volcanics and sediments. In the area mapped, a minimum thickness of 12km of predominantly mafic and ultramafic volcanics comprise the Komati, Hooggenoeg, and Kromberg Formations of the Onverwacht Group, and at least one km of predominantly pyroclastic and epiclastic sediments derived from dacitic volcanics comprise the Fig Tree Group. The Barberton greenstone belt formed primarily by ultramafic to mafic volcanism on a shallow marine platform which underwent little or no concurrent extension. Vents for this igneous activity were probably of the non-constructional fissure type. Dacitic volcanism occurred throughout the sequence in minor amounts. Large, constructional vent complexes were formed, and explosive eruptions widely dispersed pyroclastic debris. Only in the final stages of evolution of the belt did significant thrust-faulting occur, generally after, though perhaps overlapping with, the final stage of dacitic igneous activity. A discussion follows.

Hydrothermal processes above the Yellowstone magma chamber: Large hydrothermal systems and large hydrothermal explosions

USGS Publications Warehouse

Morgan, L.A.; Shanks, W.C. Pat; Pierce, K.L.

2009-01-01

Hydrothermal explosions are violent and dramatic events resulting in the rapid ejection of boiling water, steam, mud, and rock fragments from source craters that range from a few meters up to more than 2 km in diameter; associated breccia can be emplaced as much as 3 to 4 km from the largest craters. Hydrothermal explosions occur where shallow interconnected reservoirs of steam- and liquid-saturated fluids with temperatures at or near the boiling curve underlie thermal fields. Sudden reduction in confi ning pressure causes fluids to fl ash to steam, resulting in signifi cant expansion, rock fragmentation, and debris ejection. In Yellowstone, hydrothermal explosions are a potentially signifi cant hazard for visitors and facilities and can damage or even destroy thermal features. The breccia deposits and associated craters formed from hydrothermal explosions are mapped as mostly Holocene (the Mary Bay deposit is older) units throughout Yellowstone National Park (YNP) and are spatially related to within the 0.64-Ma Yellowstone caldera and along the active Norris-Mammoth tectonic corridor. In Yellowstone, at least 20 large (>100 m in diameter) hydrothermal explosion craters have been identifi ed; the scale of the individual associated events dwarfs similar features in geothermal areas elsewhere in the world. Large hydrothermal explosions in Yellowstone have occurred over the past 16 ka averaging ??1 every 700 yr; similar events are likely in the future. Our studies of large hydrothermal explosion events indicate: (1) none are directly associated with eruptive volcanic or shallow intrusive events; (2) several historical explosions have been triggered by seismic events; (3) lithic clasts and comingled matrix material that form hydrothermal explosion deposits are extensively altered, indicating that explosions occur in areas subjected to intense hydrothermal processes; (4) many lithic clasts contained in explosion breccia deposits preserve evidence of repeated fracturing and vein-fi lling; and (5) areal dimensions of many large hydrothermal explosion craters in Yellowstone are similar to those of its active geyser basins and thermal areas. For Yellowstone, our knowledge of hydrothermal craters and ejecta is generally limited to after the Yellowstone Plateau emerged from beneath a late Pleistocene icecap that was roughly a kilometer thick. Large hydrothermal explosions may have occurred earlier as indicated by multiple episodes of cementation and brecciation commonly observed in hydrothermal ejecta clasts. Critical components for large, explosive hydrothermal systems include a watersaturated system at or near boiling temperatures and an interconnected system of well-developed joints and fractures along which hydrothermal fluids flow. Active deformation of the Yellowstone caldera, active faulting and moderate local seismicity, high heat flow, rapid changes in climate, and regional stresses are factors that have strong infl uences on the type of hydrothermal system developed. Ascending hydrothermal fluids flow along fractures that have developed in response to active caldera deformation and along edges of low-permeability rhyolitic lava flows. Alteration of the area affected, self-sealing leading to development of a caprock for the hydrothermal system, and dissolution of silica-rich rocks are additional factors that may constrain the distribution and development of hydrothermal fields. A partial lowpermeability layer that acts as a cap to the hydrothermal system may produce some over-pressurization, thought to be small in most systems. Any abrupt drop in pressure initiates steam fl ashing and is rapidly transmitted through interconnected fractures that result in a series of multiple large-scale explosions contributing to the excavation of a larger explosion crater. Similarities between the size and dimensions of large hydrothermal explosion craters and thermal fields in Yellowstone may indicate that catastrophic events which result in l

Type Ia Supernova Explosions from Hybrid Carbon-Oxygen-Neon White Dwarf Progenitors

NASA Astrophysics Data System (ADS)

Willcox, Donald E.; Townsley, Dean M.; Calder, Alan C.; Denissenkov, Pavel A.; Herwig, Falk

2016-11-01

Motivated by recent results in stellar evolution that predict the existence of hybrid white dwarf (WD) stars with a C-O core inside an O-Ne shell, we simulate thermonuclear (Type Ia) supernovae from these hybrid progenitors. We use the FLASH code to perform multidimensional simulations in the deflagration-to-detonation transition (DDT) explosion paradigm. Our hybrid progenitor models were produced with the MESA stellar evolution code and include the effects of the Urca process, and we map the progenitor model to the FLASH grid. We performed a suite of DDT simulations over a range of ignition conditions consistent with the progenitor’s thermal and convective structure assuming multiple ignition points. To compare the results from these hybrid WD stars to previous results from C-O WDs, we construct a set of C-O WD models with similar properties and similarly simulate a suite of explosions. We find that despite significant variability within each suite, trends distinguishing the explosions are apparent in their {}56{Ni} yields and the kinetic properties of the ejecta. We compare our results with other recent work that studies explosions from these hybrid progenitors.

Munitions having an insensitive detonator system for initiating large failure diameter explosives

DOEpatents

Perry, III, William Leroy

2015-08-04

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.

32 CFR 174.16 - Real property containing explosive or chemical agent hazards.

Code of Federal Regulations, 2010 CFR

2010-07-01

... chemical agent hazards from past DoD military munitions-related or chemical warfare-related activities... 32 National Defense 1 2010-07-01 2010-07-01 false Real property containing explosive or chemical... REALIGNMENT Environmental Matters § 174.16 Real property containing explosive or chemical agent hazards. The...

75 FR 5345 - Agency Information Collection Activities: Proposed Collection; Comments Requested

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-02

... of information collection under review: Statement of Process-Marking of Plastic Explosives for the... Process-Marking of Plastic Explosives for the Purpose of Detection. (3) Agency form number, if any, and... Public Law 104- 132. This information will be used to ensure that plastic explosives contain a detection...

32 CFR 174.16 - Real property containing explosive or chemical agent hazards.

Code of Federal Regulations, 2014 CFR

2014-07-01

... chemical agent hazards from past DoD military munitions-related or chemical warfare-related activities... 32 National Defense 1 2014-07-01 2014-07-01 false Real property containing explosive or chemical... REALIGNMENT Environmental Matters § 174.16 Real property containing explosive or chemical agent hazards. The...

32 CFR 174.16 - Real property containing explosive or chemical agent hazards.

Code of Federal Regulations, 2012 CFR

2012-07-01

... chemical agent hazards from past DoD military munitions-related or chemical warfare-related activities... 32 National Defense 1 2012-07-01 2012-07-01 false Real property containing explosive or chemical... REALIGNMENT Environmental Matters § 174.16 Real property containing explosive or chemical agent hazards. The...

32 CFR 174.16 - Real property containing explosive or chemical agent hazards.

Code of Federal Regulations, 2013 CFR

2013-07-01

... chemical agent hazards from past DoD military munitions-related or chemical warfare-related activities... 32 National Defense 1 2013-07-01 2013-07-01 false Real property containing explosive or chemical... REALIGNMENT Environmental Matters § 174.16 Real property containing explosive or chemical agent hazards. The...

32 CFR 174.16 - Real property containing explosive or chemical agent hazards.

Code of Federal Regulations, 2011 CFR

2011-07-01

... chemical agent hazards from past DoD military munitions-related or chemical warfare-related activities... 32 National Defense 1 2011-07-01 2011-07-01 false Real property containing explosive or chemical... REALIGNMENT Environmental Matters § 174.16 Real property containing explosive or chemical agent hazards. The...

Seismic monitoring of effusive-explosive activity and large lava dome collapses during 2013-2015 at Volcán de Colima, Mexico

NASA Astrophysics Data System (ADS)

Arámbula-Mendoza, Raúl; Reyes-Dávila, Gabriel; Vargas-Bracamontes Dulce, M.; González-Amezcua, Miguel; Navarro-Ochoa, Carlos; Martínez-Fierros, Alejandro; Ramírez-Vázquez, Ariel

2018-02-01

Volcán de Colima, the most active volcano in Mexico, started a new eruptive cycle in January 2013. Since this date, the volcano has presented effusive and explosive activity. The beginning of the cycle was marked by a moderate Vulcanian explosion which had hyperbolical behavior in its precursory seismicity, possibly related to a shallow rupture process. Then, during the whole eruptive stage, the effusive activity was accompanied by low to moderate explosions. The explosions had energies mainly of 106 joules and were located between 0 and 1600 m below the crater, whereas the locations of tremor sources were found to be deeper, reaching up to 3800 m beneath the crater. Very-long-period signals (VLPs) have been observed with Vulcanian explosions that produce pyroclastic flows. A few number of volcano-tectonic events (VTs) were recognized during the studied period (2013-2015), indicating that the volcano is an open system. This was particularly evidenced in July 2015, when a new batch of magma rose rapidly without large precursors, only an accelerated increase in the number of rockfalls and associated RSEM. This event generated two large lava dome collapses with several pulses of material and pyroclastic flows that travelled up to 10.3 km from the summit. The seismic monitoring of Volcán de Colima is currently the only tool in real-time employed to assess the state of the volcanic activity. It is thus necessary to integrate new seismic methods as well as other geophysical monitoring techniques able to detect precursory signals of an impending hazardous event.

Mechanism of explosive eruptions of Kilauea Volcano, Hawaii

USGS Publications Warehouse

Dvorak, J.J.

1992-01-01

A small explosive eruption of Kilauea Volcano, Hawaii, occurred in May 1924. The eruption was preceded by rapid draining of a lava lake and transfer of a large volume of magma from the summit reservoir to the east rift zone. This lowered the magma column, which reduced hydrostatic pressure beneath Halemaumau and allowed groundwater to flow rapidly into areas of hot rock, producing a phreatic eruption. A comparison with other events at Kilauea shows that the transfer of a large volume of magma out of the summit reservoir is not sufficient to produce a phreatic eruption. For example, the volume transferred at the beginning of explosive activity in May 1924 was less than the volumes transferred in March 1955 and January-February 1960, when no explosive activity occurred. Likewise, draining of a lava lake and deepening of the floor of Halemaumau, which occurred in May 1922 and August 1923, were not sufficient to produce explosive activity. A phreatic eruption of Kilauea requires both the transfer of a large volume of magma from the summit reservoir and the rapid removal of magma from near the surface, where the surrounding rocks have been heated to a sufficient temperature to produce steam explosions when suddenly contacted by groundwater. ?? 1992 Springer-Verlag.

77 FR 43366 - Agency Information Collection Activities: Proposed Collection; Comments Requested: Voluntary...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-24

... DEPARTMENT OF JUSTICE Bureau of Alcohol, Tobacco, Firearms and Explosives [OMB Number 1140-0092] Agency Information Collection Activities: Proposed Collection; Comments Requested: Voluntary Magazine... Magazine Questionnaire for Agencies/Entities Who Store Explosives. (3) Agency form number, if any, and the...

Investigation of ionospheric disturbances and associated diagnostic techniques. Final report, 1 January 1992-31 December 1994

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duncan, L.M.

1995-12-12

The objectives of this research and development program were to conduct simulation modeling of the generation and propagation of atmospheric acoustic signals associated with surface and subsurface ground disturbances; to construct an experimental measurement system for exploratory research studies of acoustic generated ionospheric disturbances; to model high power radio wave propagation through the ionosphere, including nonlinear wave plasma interaction effects; and to assist in the assessment of diagnostic systems for observation of ionospheric modification experiments using existing and planned high latitude high power RF transmitting facilities. A computer simulation of ionospheric response to ground launched acoustic pulses was constructed andmore » results compared to observational data associated with HF and incoherent scatter radar measurements of ionospheric effects produced by earthquakes and ground level explosions. These results were then utilized to help define the design, construct and test for an HF Doppler radar system. In addition, an assessment was conducted of ionospheric diagnostic instruments proposed for the Air Force/Navy High Frequency Active Auroral Research Program (HAARP).« less

Detection of nitro-based and peroxide-based explosives by fast polarity-switchable ion mobility spectrometer with ion focusing in vicinity of Faraday detector.

PubMed

Zhou, Qinghua; Peng, Liying; Jiang, Dandan; Wang, Xin; Wang, Haiyan; Li, Haiyang

2015-05-29

Ion mobility spectrometer (IMS) has been widely deployed for on-site detection of explosives. The common nitro-based explosives are usually detected by negative IMS while the emerging peroxide-based explosives are better detected by positive IMS. In this study, a fast polarity-switchable IMS was constructed to detect these two explosive species in a single measurement. As the large traditional Faraday detector would cause a trailing reactant ion peak (RIP), a Faraday detector with ion focusing in vicinity was developed by reducing the detector radius to 3.3 mm and increasing the voltage difference between aperture grid and its front guard ring to 591 V, which could remove trailing peaks from RIP without loss of signal intensity. This fast polarity-switchable IMS with ion focusing in vicinity of Faraday detector was employed to detect a mixture of 10 ng 2,4,6-trinitrotoluene (TNT) and 50 ng hexamethylene triperoxide diamine (HMTD) by polarity-switching, and the result suggested that [TNT-H](-) and [HMTD+H](+) could be detected in a single measurement. Furthermore, the removal of trailing peaks from RIP by the Faraday detector with ion focusing in vicinity also promised the accurate identification of KClO4, KNO3 and S in common inorganic explosives, whose product ion peaks were fairly adjacent to RIP.

Electrical activity during the 2006 Mount St. Augustine volcanic eruptions

USGS Publications Warehouse

Thomas, Ronald J.; Krehbiel, Paul R.; Rison, William; Edens, H. E.; Aulich, G. D.; McNutt, S.R.; Tytgat, Guy; Clark, E.

2007-01-01

By using a combination of radio frequency time-of-arrival and interferometer measurements, we observed a sequence of lightning and electrical activity during one of Mount St. Augustine's eruptions. The observations indicate that the electrical activity had two modes or phases. First, there was an explosive phase in which the ejecta from the explosion appeared to be highly charged upon exiting the volcano, resulting in numerous apparently disorganized discharges and some simple lightning. The net charge exiting the volcano appears to have been positive. The second phase, which followed the most energetic explosion, produced conventional-type discharges that occurred within plume. Although the plume cloud was undoubtedly charged as a result of the explosion itself, the fact that the lightning onset was delayed and continued after and well downwind of the eruption indicates that in situ charging of some kind was occurring, presumably similar in some respects to that which occurs in normal thunderstorms.

The Volcanic History of Mars and Influences on Carbon Outgassing

NASA Astrophysics Data System (ADS)

Bleacher, J. E.; Whelley, P.

2015-12-01

Exploration of Mars has revealed some of the most impressive volcanic landforms found throughout the solar system. Volatiles outgassed from volcanoes were likely to have strongly influenced atmospheric chemistry and affected the martian climate. On Earth the role of carbon involved in volcanic outgassing is strongly influenced by tectonic setting, with the greatest weight percent contributions coming from partial mantle melts associated with hot spot volcanism. Most martian volcanic centers appear to represent this style of volcanism. Thus, one important factor in understanding the martian carbon cycle through time is understanding this volatile's link to the planet's volcanic history. The identified volcanic constructs on Mars are not unlike those of the Earth suggesting similar magmatic and eruptive processes. However, the dimensions of many martian volcanic features are significantly larger. The distribution of volcanoes and volcanic deposits on Mars are not spatially or temporally uniform. Large volcanoes (> 100 km diameter) are spatially concentrated in volcanic provinces that likely represent focused upwellings or zones of crustal weakness that enabled magma ascension. Smaller (10s km diameters) volcanoes such as cones, low shields and fissures are often grouped into fields and their lava flows coalesce to produce low slope plains. In some cases plains lava fields are quite extensive with little to no evidence for the volcanic constructs. Although martian volcanism appears to have been dominated by effusive eruptions with likely contributions from passive degassing from the interior, explosive volcanic centers and deposits are known to exist. After the development of a martian crust the planet's volcanic style appears to have evolved from early explosive activity to effusive activity centered at major volcanoes to effusive distributed activity in fields. However, questions remain as to whether or not these styles significantly overlapped in time and if so, why? As scientists continue to learn more about carbon's role in terrestrial volcanism, it is reasonable to question how and how much carbon was involved in different styles of martian volcanic activity and how carbon and other volatiles have affected the martian atmosphere and climate through time.

Local infrasound observations of large ash explosions at Augustine Volcano, Alaska, during January 11–28, 2006

USGS Publications Warehouse

Petersen, Tanja; De Angelis, Silvio; Tytgat, Guy; McNutt, Stephen R.

2006-01-01

We present and interpret acoustic waveforms associated with a sequence of large explosion events that occurred during the initial stages of the 2006 eruption of Augustine Volcano, Alaska. During January 11–28, 2006, 13 large explosion events created ash-rich plumes that reached up to 14 km a.s.l., and generated atmospheric pressure waves that were recorded on scale by a microphone located at a distance of 3.2 km from the active vent. The variety of recorded waveforms included sharp N-shaped waves with durations of a few seconds, impulsive signals followed by complex codas, and extended signals with emergent character and durations up to minutes. Peak amplitudes varied between 14 and 105 Pa; inferred acoustic energies ranged between 2×108 and 4×109 J. A simple N-shaped short-duration signal recorded on January 11, 2006 was associated with the vent-opening blast that marked the beginning of the explosive eruption sequence. During the following days, waveforms with impulsive onsets and extended codas accompanied the eruptive activity, which was characterized by explosion events that generated large ash clouds and pyroclastic flows along the flanks of the volcano. Continuous acoustic waveforms that lacked a clear onset were more common during this period. On January 28, 2006, the occurrence of four large explosion events marked the end of this explosive eruption phase at Augustine Volcano. After a transitional period of about two days, characterized by many small discrete bursts, the eruption changed into a stage of more sustained and less explosive activity accompanied by the renewed growth of a summit lava dome.

A Risk Management Framework to Characterize Black Swan Risks: A Case Study of Lightning Effects on Insensitive High Explosives

NASA Astrophysics Data System (ADS)

Sanders, Gary A.

Effective and efficient risk management processes include the use of high fidelity modeling and simulation during the concept exploration phase as part of the technology and risk assessment activities, with testing and evaluation tasks occurring in later design development phases. However, some safety requirements and design architectures may be dominated by the low probability/high consequence "Black Swan" vulnerabilities that require very early testing to characterize and efficiently mitigate. Failure to address these unique risks has led to catastrophic systems failures including the space shuttle Challenger, Deepwater Horizon, Fukushima nuclear reactor, and Katrina dike failures. Discovering and addressing these risks later in the design and development process can be very costly or even lead to project cancellation. This paper examines the need for risk management process adoption of early hazard phenomenology testing to inform the technical risk assessment, requirements definition and conceptual design. A case study of the lightning design vulnerability of the insensitive high explosives being used in construction, mining, demolition, and defense industries will be presented to examine the impact of this vulnerability testing during the concept exploration phase of the design effort. While these insensitive high explosives are far less sensitive to accidental initiation by fire, impact, friction or even electrical stimuli, their full range of sensitivities have not been characterized and ensuring safe engineering design and operations during events such as lightning storms requires vulnerability testing during the risk assessment phase.

30 CFR 817.66 - Use of explosives: Blasting signs, warnings, and access control.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Use of explosives: Blasting signs, warnings... STANDARDS-UNDERGROUND MINING ACTIVITIES § 817.66 Use of explosives: Blasting signs, warnings, and access control. (a) Blasting signs. Blasting signs shall meet the specifications of § 817.11. The operator shall...

30 CFR 816.66 - Use of explosives: Blasting signs, warnings, and access control.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Use of explosives: Blasting signs, warnings... STANDARDS-SURFACE MINING ACTIVITIES § 816.66 Use of explosives: Blasting signs, warnings, and access control. (a) Blasting signs. Blasting signs shall meet the specifications of § 816.11. The operator shall— (1...

30 CFR 817.66 - Use of explosives: Blasting signs, warnings, and access control.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Use of explosives: Blasting signs, warnings... STANDARDS-UNDERGROUND MINING ACTIVITIES § 817.66 Use of explosives: Blasting signs, warnings, and access control. (a) Blasting signs. Blasting signs shall meet the specifications of § 817.11. The operator shall...

30 CFR 816.66 - Use of explosives: Blasting signs, warnings, and access control.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Use of explosives: Blasting signs, warnings... STANDARDS-SURFACE MINING ACTIVITIES § 816.66 Use of explosives: Blasting signs, warnings, and access control. (a) Blasting signs. Blasting signs shall meet the specifications of § 816.11. The operator shall— (1...

30 CFR 816.66 - Use of explosives: Blasting signs, warnings, and access control.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Use of explosives: Blasting signs, warnings... STANDARDS-SURFACE MINING ACTIVITIES § 816.66 Use of explosives: Blasting signs, warnings, and access control. (a) Blasting signs. Blasting signs shall meet the specifications of § 816.11. The operator shall— (1...

30 CFR 817.66 - Use of explosives: Blasting signs, warnings, and access control.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Use of explosives: Blasting signs, warnings... STANDARDS-UNDERGROUND MINING ACTIVITIES § 817.66 Use of explosives: Blasting signs, warnings, and access control. (a) Blasting signs. Blasting signs shall meet the specifications of § 817.11. The operator shall...

30 CFR 817.66 - Use of explosives: Blasting signs, warnings, and access control.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Use of explosives: Blasting signs, warnings... STANDARDS-UNDERGROUND MINING ACTIVITIES § 817.66 Use of explosives: Blasting signs, warnings, and access control. (a) Blasting signs. Blasting signs shall meet the specifications of § 817.11. The operator shall...

30 CFR 817.66 - Use of explosives: Blasting signs, warnings, and access control.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Use of explosives: Blasting signs, warnings... STANDARDS-UNDERGROUND MINING ACTIVITIES § 817.66 Use of explosives: Blasting signs, warnings, and access control. (a) Blasting signs. Blasting signs shall meet the specifications of § 817.11. The operator shall...

30 CFR 816.66 - Use of explosives: Blasting signs, warnings, and access control.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Use of explosives: Blasting signs, warnings... STANDARDS-SURFACE MINING ACTIVITIES § 816.66 Use of explosives: Blasting signs, warnings, and access control. (a) Blasting signs. Blasting signs shall meet the specifications of § 816.11. The operator shall— (1...

30 CFR 816.66 - Use of explosives: Blasting signs, warnings, and access control.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Use of explosives: Blasting signs, warnings... STANDARDS-SURFACE MINING ACTIVITIES § 816.66 Use of explosives: Blasting signs, warnings, and access control. (a) Blasting signs. Blasting signs shall meet the specifications of § 816.11. The operator shall— (1...

78 FR 26655 - Agency Information Collection Activities; Proposed Collection; Comments Requested: Statement of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-07

...-Marking of Plastic Explosives for the Purpose of Detection ACTION: 30-Day notice. The Department of...) Title of the Form/Collection: Statement of Process-Marking of Plastic Explosives for the Purpose of... used to ensure that plastic explosives contain a detection agent as required by law. (5) An estimate of...

Common explosives (TNT, RDX, HMX) and their fate in the environment: Emphasizing bioremediation.

PubMed

Chatterjee, Soumya; Deb, Utsab; Datta, Sibnarayan; Walther, Clemens; Gupta, Dharmendra K

2017-10-01

Explosive materials are energetic substances, when released into the environment, contaminate by posing toxic hazards to environment and biota. Throughout the world, soils are contaminated by such contaminants either due to manufacturing operations, military activities, conflicts of different levels, open burning/open detonation (OB/OD), dumping of munitions etc. Among different forms of chemical explosives, 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and octahydro-1,3,5,7-tetranitro- 1,3,5,7-tetrazocine (HMX) are most common. These explosives are highly toxic as USEPA has recommended restrictions for lifetime contact through drinking water. Although, there are several utilitarian aspects in anthropogenic activities, however, effective remediation of explosives is very important. This review article emphasizes the details of appropriate practices to ameliorate the contamination. Critical evaluation has also been made to encompass the recent knowledge and advancement about bioremediation and phytoremediation of explosives (especially TNT, RDX and HMX) along with the molecular mechanisms of biodegradation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dispensing Pollen via Catapult: Explosive Pollen Release in Mountain Laurel (Kalmia latifolia).

PubMed

Switzer, Callin M; Combes, Stacey A; Hopkins, Robin

2018-06-01

The astonishing amount of floral diversity has inspired countless assumptions about the function of diverse forms and their adaptive significance, yet many of these hypothesized functions are untested. We investigated an often-repeated adaptive hypothesis about how an extreme floral form functions. In this study, we conducted four investigations to understand the adaptive function of explosive pollination in Kalmia latifolia, the mountain laurel. We first performed a kinematic analysis of anther movement. Second, we constructed a heat map of pollen trajectories in three-dimensional space. Third, we conducted field observations of pollinators and their behaviors while visiting K. latifolia. Finally, we conducted a pollination experiment to investigate the importance of pollinators for fertilization success. Our results suggest that insect visitation dramatically improves fertilization success and that bees are the primary pollinators that trigger explosive pollen release.

77 FR 5845 - Agency Information Collection Activities: Proposed Collection; Comments Requested: Report of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-06

...] Agency Information Collection Activities: Proposed Collection; Comments Requested: Report of Theft or... currently approved collection. (2) Title of the Form/Collection: Report of Theft or Loss of Explosives. (3... for-profit. Other: None. Need for Collection Losses or theft of explosives must, by statute be...

78 FR 57415 - Agency Information Collection Activities; Proposed Collection; Comments Requested: Request for...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-18

... DEPARTMENT OF JUSTICE Bureau of Alcohol, Tobacco, Firearms and Explosives [OMB Number 1140-NEW] Agency Information Collection Activities; Proposed Collection; Comments Requested: Request for ATF Background Investigation Information ACTION: 60-Day Notice. The Department of Justice (DOJ), Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF),...

78 FR 77167 - Agency Information Collection Activities; Proposed Collection; Comments Requested: Supplemental...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-20

... DEPARTMENT OF JUSTICE Bureau of Alcohol, Tobacco, Firearms and Explosives [OMB Number 1140-0097] Agency Information Collection Activities; Proposed Collection; Comments Requested: Supplemental Information on Water Quality Considerations ACTION: 60-day notice. The Department of Justice (DOJ), Bureau of Alcohol, Tobacco, Firearms and Explosives ...

78 FR 2441 - Agency Information Collection Activities: Proposed Collection; Comments Requested, Application...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-11

... DEPARTMENT OF JUSTICE Bureau of Alcohol, Tobacco, Firearms and Explosives [OMB Number 1140-0018] Agency Information Collection Activities: Proposed Collection; Comments Requested, Application for Federal Firearms License ACTION: 30-Day notice. The Department of Justice (DOJ), Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) will be...

Analysis of the Explosive Internal Impact on the Barriers of Building Structures

NASA Astrophysics Data System (ADS)

Siwiński, Jarosław; Stolarski, Adam

2017-10-01

Work issues concern the safety of construction in relation to the hazards arising from explosion of the explosive charge located inside the building. The algorithms proposed in the paper for determining the parameters of the overpressure wave resulting from the detonation of clustered explosive charges, determine the basis for numerical simulation analyzes. Determination of the maximum value of peak pressure on the wave forehead of an internal explosion is presented on the basis of reflected wave analysis. Changeability in time of the internal explosion action describes the overpressure phase only. The analysis of the load caused by the internal explosive charge detonation was carried out under conditions of the undisturbed standard atmosphere. A load determination algorithm has been developed, taking into account the geometrical characteristics of the building barriers and the rooms as well as the parameters of environment in which the detonation occurs. The way of taking into account the influence of venting surfaces, i.e. windows, doors, ventilation ducts, on the overpressure wave parameters, was presented. Discloses a method to take into account the effect of the surface relief, i.e. windows, doors, air ducts, pressure wave parameters. Modification of the method for explosive overpressure determination presented by Cormie, Smith, Mays (2009), was proposed in the paper. This modification was developed on the basis of substitute impulse analysis for multiple overpressure pulses. In order to take into account the pressure distribution of explosive gases on the barrier surface, the method of modification the relationship for determination the changeability over time and space of the pressure of explosive gases, was presented. For this purpose, the changeability of the pressure wave angles of incidence to the barrier and the distance of the explosive charge to any point on the surface of the barrier, was taken into account. Based on the developed procedure, the overpressure changeability over time was determined for selected measurement points of the reference room. A comparative analysis of the determined loadings with experimental results and theoretical results of other authors, taken from the original work of Weerhiejm et al. (2012), was carried out.

Long-term variations in explosion dynamics at Santiaguito volcano

NASA Astrophysics Data System (ADS)

Lamb, Oliver; De Angelis, Silvio; Lavallée, Yan; Lamur, Anthony; Hornby, Adrian; Von Aulock, Felix; Kendrick, Jackie; Chigna, Gustavo; Rietbrock, Andreas

2017-04-01

Here we present two years of seismic and infrasound observations of ash-and-gas explosions recorded during an ongoing multi-disciplinary experiment at the Santiaguito lava dome complex, Guatemala. Due to the occurrence of regular explosive activity since the early 1970's, the volcano is an ideal laboratory for the study of the eruption dynamics of long-lived silicic eruptions. The instrument network, deployed between 0.5 and 7 km from the active vent, includes 5 broadband and 6 short-period seismometers, as well as 5 infrasound sensors. Seismo-acoustic data are complemented by thermal infrared imagery, visual observations from an unmanned aerial vehicle, and geochemical measurements of eruptive products. In mid-2015, a major shift in activity took place at Santiaguito. Vulcanian explosions became more energetic and less regular, and were often accompanied by pyroclastic density currents. Important morphological changes were observed at the active El Caliente dome, as the lava-filled crater was excavated by a sequence of vigorous explosions to a depth of at least 150 m. Variations in the relative arrival times of seismic and infrasound signals suggest a significant deepening of the explosion initiation point inside the conduit. This shift in behaviour likely represents a change in the eruptive mechanism in the upper conduit beneath El Caliente, possibly triggered by disequilibrium at a greater depth in the volcanic system. Our observations suggest a reactivation of the deep magmatic system at Santiaguito, with little precursory activity. The results of this multi-parameteric monitoring experiment have specific implications for hazard assessment at Santiaguito, and contributes to understanding the processes that control changes in eruptive regime at lava dome volcanoes.

A bestiary of ordinary vent activities at Stromboli (and what it tells us about vent conditions)

NASA Astrophysics Data System (ADS)

Gaudin, Damien; Taddeucci, Jacopo; Scarlato, Piergiorgio

2015-04-01

Normal active degassing at Stromboli (Aeolian Islands, Italy) is traditionally divided in two classes. Puffing correspond to the frequent (~1 Hz) release of small gas pockets (0.5 - 1 m of diameter) at low exit velocities (5 - 15 m/s). Whereas, Strombolian explosions occur at a frequency of 1 - 10 per hour, and are characterized the ejection of bombs and/or ash at high velocities (50 - 400 m/s). In order to get a broader overview of two types of degassing, we used a thermal high speed FLIR SC655 camera to monitor the temperature anomalies generated by the expelled gas, ash, and/or bombs. The enhanced time and spatial resolutions of the camera (200 frames per second, 15 cm wide pixels) enables to use numerical algorithms to distinguish and characterize individual ejection events. In particular, for each explosion and puff, we compute the temperature, the volume, the exit point and the rise velocities of the expelled material. These values, as well as the frequency of the release events, are used to portray a total of 12 vent activities, observed during three field campaigns in 2012, 2013 and 2014. Sustained puffing was visible on 7 cases, with an intensity ranging on at least two orders of magnitude. Although the released gas volume is sometimes highly variable, on some cases, constant sized puffs allows to define a typical discharge frequency ranging between 0.4 and 1.5 Hz. Regular Strombolian explosions, with various duration, intensity and ash contents, are reported in 6 cases, 2 of them simultaneously presenting a puffing activity. In some cases, we noticed modifications of the vent activity just before the explosions. These precursors, usually lasting about 1 second but occasionally reaching 10 seconds, can be sorted into 1) increase of the puffing activity ; 2) emission of gas plumes ; 3) inflation of the visible vent surface. Finally, one vent activity was hybrid between puffing and Strombolian explosions, with frequent explosions (1 Hz) ejecting numerous pyroclasts at an intermediate velocity (15 - 30 m/s). This latter case suggests that puffing and normal Strombolian explosions are driven by a similar mechanism, modulated by different vent conditions and/or gas supply. Crucial insights about explosion mechanism and vents conditions can be derived from the interpretation of explosion precursors. For example, the amplitude surface inflation is significantly smaller that what would be expected for the decompression of a slug in a single-viscosity conduit, suggesting the existence of a high viscosity plug limiting gas expansion close to the surface. In addition, the release of low pressurized gas or the increase of puffing activity before the Strombolian explosions suppose the existence of a shallow bubble reservoir. We hypothesize that this layer could originate at the base of the high-viscosity plug, where the bubble rise velocity locally decreases. The stress changes preceding the slug rise might decrease the plug viscosity through the generation of fractures, allowing the release of these precursors.

Prediction of ground motion and dynamic stress change in Baekdusan (Changbaishan) volcano caused by a North Korean nuclear explosion.

PubMed

Hong, Tae-Kyung; Choi, Eunseo; Park, Seongjun; Shin, Jin Soo

2016-02-17

Strong ground motions induce large dynamic stress changes that may disturb the magma chamber of a volcano, thus accelerating the volcanic activity. An underground nuclear explosion test near an active volcano constitutes a direct treat to the volcano. This study examined the dynamic stress changes of the magma chamber of Baekdusan (Changbaishan) that can be induced by hypothetical North Korean nuclear explosions. Seismic waveforms for hypothetical underground nuclear explosions at North Korean test site were calculated by using an empirical Green's function approach based on a source-spectral model of a nuclear explosion; such a technique is efficient for regions containing poorly constrained velocity structures. The peak ground motions around the volcano were estimated from empirical strong-motion attenuation curves. A hypothetical M7.0 North Korean underground nuclear explosion may produce peak ground accelerations of 0.1684 m/s(2) in the horizontal direction and 0.0917 m/s(2) in the vertical direction around the volcano, inducing peak dynamic stress change of 67 kPa on the volcano surface and ~120 kPa in the spherical magma chamber. North Korean underground nuclear explosions with magnitudes of 5.0-7.6 may induce overpressure in the magma chamber of several tens to hundreds of kilopascals.

Minutes of the Explosives Safety Seminar (20th) Held at OMNI international Hotel, Norfolk, Virginia on 24-26 August 1982. Volume I

DTIC Science & Technology

1982-08-01

between one that provides for total protection of life and property and one that per- mits operators to conduct activities in a " laisse - faire " manner...Workers. AD-PO00 456 General Risk Analysis Methodological Implications to Explosives Risk Management Systems. AD-PO0O 457 Risk Analysis for Explosives...THE EFFECTS OF THE HEALTH AND SAFETY AT WORK ACT, 1974, ON MILITARY EXPLOSIVES SAFETY MANAGEMENT IN THE UNITED KINGDOM ........................ 7 Air

30 CFR 817.62 - Use of explosives: Preblasting survey.

Code of Federal Regulations, 2010 CFR

2010-07-01

... ACTIVITIES § 817.62 Use of explosives: Preblasting survey. (a) At least 30 days before initiation of blasting... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Use of explosives: Preblasting survey. 817.62... located within 1/2 mile of the permit area how to request a preblasting survey. (b) A resident or owner of...

30 CFR 816.62 - Use of explosives: Preblasting survey.

Code of Federal Regulations, 2010 CFR

2010-07-01

... ACTIVITIES § 816.62 Use of explosives: Preblasting survey. (a) At least 30 days before initiation of blasting... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Use of explosives: Preblasting survey. 816.62... located within 1/2 mile of the permit area how to request a preblasting survey. (b) A resident or owner of...

Low-cost detection of RC-IED activation signals in VHF band

NASA Astrophysics Data System (ADS)

Camargo Suarez, Victor Hugo; Marulanda B., Jose Ignacio

2014-05-01

The proliferation of Radio Controlled Improvised Explosive Devices (RC-IED) is a growing threat around the world. The ease of construction and low cost of these devices are transforming common things in lethal tramps. The fight against this threats normally involves the use of sophisticated and expensive equipment of Electronic Warfare based on high speed DSP systems, just to detect the presence of detonation signals. In this work is showed how to find activation signals based on the characteristic of the power in a specific band and the previous knowledge about the detonation signals. As proof of concept we have taken the information about the RC-IEDs used in the Colombian conflict and develop an algorithm to find detonation signals based on the measured power in frequencies between 136 MHz and 174 MHz (2 meter civil band)

Formation of Load Parameters of Destroyed Massife in Explosion of Multicharge Composition with Separation of its Parts by Profile Inert Interval

NASA Astrophysics Data System (ADS)

Paramonov, G. P.; Mysin, A. V.; Babkin, R. S.

2017-10-01

The paper introduces construction of multicharge composition with separation of parts by the profile inert interval. On the basis of the previous researches, the pulse-forming process at explosion of the borehole multicharge taking into account the offered design is considered. The physical model for definition of reflected wavelet taking into account an increment of radius of cross section of a charging cavity and the expiration of detonation products is offered. A technique is developed for numerical modeling of gas-dynamic processes in a borehole with a change in the axial channel of a profile inert interval caused by a high-temperature flow of gaseous products of an explosion. The authors obtained the dependence of the change in mean pressure on the borehole wall on time for each of the parts of the multicharge. To blast a series of charges of the proposed design, taking into account optimization of the stress fields of neighboring charges, the delay interval is determined for a short-delayed explosion.

Steam explosions, earthquakes, and volcanic eruptions -- what's in Yellowstone's future?

USGS Publications Warehouse

Lowenstern, Jacob B.; Christiansen, Robert L.; Smith, Robert B.; Morgan, Lisa A.; Heasler, Henry

2005-01-01

Yellowstone, one of the world?s largest active volcanic systems, has produced several giant volcanic eruptions in the past few million years, as well as many smaller eruptions and steam explosions. Although no eruptions of lava or volcanic ash have occurred for many thousands of years, future eruptions are likely. In the next few hundred years, hazards will most probably be limited to ongoing geyser and hot-spring activity, occasional steam explosions, and moderate to large earthquakes. To better understand Yellowstone?s volcano and earthquake hazards and to help protect the public, the U.S. Geological Survey, the University of Utah, and Yellowstone National Park formed the Yellowstone Volcano Observatory, which continuously monitors activity in the region.

Spattering activity at Halemáumáu in 2015 and the transition between Hawaiian and Strombolian eruptions

NASA Astrophysics Data System (ADS)

Mintz, B. G.; Houghton, B. F.; Orr, T. R.; Taddeucci, J.; Gaudin, D.; Kueppers, U.; Carey, R.; Scarlato, P.; Del Bello, E.

2016-12-01

Explosive activity in 2015 at the free surface of the Halemáumáu lava lake at Kīlauea showed features of both Hawaiian fountaining and Strombolian explosivity. Like low Hawaiian fountains, spattering events often persisted for tens of minutes or hours. However, like Strombolian explosions, the activity consisted of a series of bursting of discrete, meter-sized gas bubbles. Each bubble burst threw fluidal bombs, with meter to decimeter diameters, to elevations of meters to a few tens of meters above the collapsing bubble remnant. Initial velocities of the pyroclasts were lower than either Strombolian explosions or high Hawaiian fountains, typically only 7 to 14 meters/second on average.Although some events were triggered by short-lived rock falls that penetrated the crust of the lava lake, the resulting outgassing activity would become self-sustaining and persistent. Activity was at times, confined to a single point source, to several point sources, or along arcs extending tens of meters parallel to the lake margin.This activity represents another type of behavior exhibited by basaltic volcanoes and provides greater insight into the spectrum between Hawaiian fountaining and Strombolian explosivity. Consequently, this activity is highly instructive in terms of: (a) the diversity of degassing/outgassing possible at basaltic volcanoes and (b) the controls on mechanically coupled versus decoupled behavior of the exsolved bubbles. The 2015 Halemáumáu activity was often continuous over similar timescales to Hawaiian fountaining but was markedly less steady than high fountains. A significant portion of the gas phase was released as discrete bubble bursts, but with frequencies two or three orders of magnitude higher than at Stromboli, which permitted sustained but not steady events.

Statistical Approach to Detection of Strombolian Activity in Satellite Data

NASA Astrophysics Data System (ADS)

Worden, A. K.; Dehn, J.; Ripepe, M.; Harris, A. J.

2010-12-01

Strombolian activity across the remote volcanoes of the Aleutian Islands and Kamchatka Peninsula cannot be monitored easily or safely by direct methods. Satellite remote sensing offers a useful means to routinely monitor these volcanoes. To model the expected time-dependent thermal signal recorded by the satellite-sensor, we carried out laboratory-based experiments and collected field data for cooling spatter and bomb fields. Preliminary laboratory work focused on finding an acceptable lava analog, as well as scaled pressures and vent sizes. Honey emitted from 0.5-3.8 cm diameter vents by explosions with pressures of around 0.05 MPa seemed to work the best. Scaled explosions were recorded with a FLIR thermal camera and a digital video camera. Explosions at Stromboli Volcano in Italy were also recorded with the same thermal camera over a period of days in May and June, 2010, and were compared to the scaled explosions. In both the modeled and actual explosions, vent diameter directly dictates the type of explosion and deposit distribution ranging from intense jetting from small vents to diffuse spattering from larger vents. The style of emission controls the area of, and distribution of bombs within, the resulting bomb field. This, in turn, influences the cooling rate of the bomb field. The cooling rate of spatter and bomb fields (most likely the source of thermal anomalies in satellite data) for both modeled and actual explosions compared well, and is on the order of seconds to minutes. For a single explosion of average size, the thermal signal is detectable by satellite for a time period in terms of tens of seconds. Thus, in order to see a thermal signature related to a strombolian explosion, a satellite must pass over the volcano (with acceptable geometries) within about a minute of an explosion. A volcano with 70 explosions per day would produce roughly an hour of detectable thermal anomalies. With about a dozen possible NOAA and NASA satellite overpasses daily, dependant on weather and viewing geometry, an anomaly would be seen every couple of days and almost certainly once a week. By calibrating events observed by satellite with events recorded in infrasonic, seismic, and FLIR data a tool can be developed to gauge increasing or decreasing strombolian activity at remote volcanoes.

Apparatus and methods for real-time detection of explosives devices

DOEpatents

Blackburn, Brandon W [Idaho Falls, ID; Hunt, Alan W [Pocatello, ID; Chichester, David L [Idaho Falls, ID

2014-01-07

The present disclosure relates, according to some embodiments, to apparatus, devices, systems, and/or methods for real-time detection of a concealed or camouflaged explosive device (e.g., EFPs and IEDs) from a safe stand-off distance. Apparatus, system and/or methods of the disclosure may also be operable to identify and/or spatially locate and/or detect an explosive device. An apparatus or system may comprise an x-ray generator that generates high-energy x-rays and/or electrons operable to contact and activate a metal comprised in an explosive device from a stand-off distance; and a detector operable to detect activation of the metal. Identifying an explosive device may comprise detecting characteristic radiation signatures emitted by metals specific to an EFP, an IED or a landmine. Apparatus and systems of the disclosure may be mounted on vehicles and methods of the disclosure may be performed while moving in the vehicle and from a safe stand-off distance.

Detonation equation of state at LLNL, 1995. Revision 3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Souers, P.C.; Wu, B.; Haselman, L.C. Jr.

1996-02-01

JWL`s and 1-D Look-up tables are shown to work for ``one-track`` experiments like cylinder shots and the expanding sphere. They fail for ``many-track`` experiments like the compressed sphere. As long as the one-track experiment has dimensions larger than the explosive`s reaction zone and the explosive is near-ideal, a general JWL with R{sub 1} = 4.5 and R{sub 2} = 1.5 can be constructed, with both {omega} and E{sub o} being calculated from thermochemical codes. These general JWL`s allow comparison between various explosives plus recalculation of the JWL for different densities. The Bigplate experiment complements the cylinder test by providing continuousmore » oblique angles of shock incidence from 0{degrees} to 70{degrees}. Explosive reaction zone lengths are determined from metal plate thicknesses, extrapolated run-to-detonation distances, radius size effects and detonation front curvature. Simple theories of the cylinder test, Bigplate, the cylinder size effect and detonation front curvature are given. The detonation front lag at the cylinder edge is shown to be proportional to the half-power of the reaction zone length. By calibrating for wall blow-out, a full set of reaction zone lengths from PETN to ANFO are obtained. The 1800--2100 K freezing effect is shown to be caused by rapid cooling of the product gases. Compiled comparative data for about 80 explosives is listed. Ten Chapters plus an Appendix.« less

UNIFYING THE ZOO OF JET-DRIVEN STELLAR EXPLOSIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lazzati, Davide; Blackwell, Christopher H.; Morsony, Brian J.

We present a set of numerical simulations of stellar explosions induced by relativistic jets emanating from a central engine sitting at the center of compact, dying stars. We explore a wide range of durations of the central engine activity, two candidate stellar progenitors, and two possible values of the total energy release. We find that even if the jets are narrowly collimated, their interaction with the star unbinds the stellar material, producing a stellar explosion. We also find that the outcome of the explosion can be very different depending on the duration of the engine activity. Only the longest-lasting enginesmore » result in successful gamma-ray bursts. Engines that power jets only for a short time result in relativistic supernova (SN) explosions, akin to observed engine-driven SNe such as SN2009bb. Engines with intermediate durations produce weak gamma-ray bursts, with properties similar to nearby bursts such as GRB 980425. Finally, we find that the engines with the shortest durations, if they exist in nature, produce stellar explosions that lack sizable amounts of relativistic ejecta and are therefore dynamically indistinguishable from ordinary core-collapse SNe.« less

UHPC for Blast and Ballistic Protection, Explosion Testing and Composition Optimization

NASA Astrophysics Data System (ADS)

Bibora, P.; Drdlová, M.; Prachař, V.; Sviták, O.

2017-10-01

The realization of high performance concrete resistant to detonation is the aim and expected outcome of the presented project, which is oriented to development of construction materials for larger objects as protective walls and bunkers. Use of high-strength concrete (HSC / HPC - “high strength / performance concrete”) and high-fiber reinforced concrete (UHPC / UHPFC -“Ultra High Performance Fiber Reinforced Concrete”) seems to be optimal for this purpose of research. The paper describes the research phase of the project, in which we focused on the selection of specific raw materials and chemical additives, including determining the most suitable type and amount of distributed fiber reinforcement. Composition of UHPC was optimized during laboratory manufacture of test specimens to obtain the best desired physical- mechanical properties of developed high performance concretes. In connection with laboratory testing, explosion field tests of UHPC specimens were performed and explosion resistance of laboratory produced UHPC testing boards was investigated.

Ultrasonic approach to the synthesis of HMX@TATB core-shell microparticles with improved mechanical sensitivity.

PubMed

Huang, Bing; Hao, Xiaofei; Zhang, Haobin; Yang, Zhijian; Ma, Zhigang; Li, Hongzhen; Nie, Fude; Huang, Hui

2014-07-01

To improve the safety of sensitive explosive HMX while maintaining explosion performance, a moderately powerful but insensitive explosive TATB was used to coat HMX microparticles via a facile ultrasonic method. By using Estane as surface modifier and nano-sized TATB as the shell layer, the HMX@TATB core-shell microparticles with a monodisperse size and compact shell structure were successfully constructed. Both scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) results confirmed the formation of perfect core-shell structured composites. Based on a systematic and comparative study of the effect of experimental conditions, a possible formation mechanism of core-shell structure was proposed in detail. Moreover, the perfect core-shell HMX@TATB microparticles exhibited a unique thermal behavior and significantly improved mechanical sensitivity compared with that of the physical mixture. Copyright © 2014 Elsevier B.V. All rights reserved.

The Nuclear Barcode: a New Taggant for Identifying Explosives

NASA Astrophysics Data System (ADS)

Seman, James; Johnson, Catherine; Castaño, Carlos

2017-06-01

Creating an effective taggant system for explosives is a challenging problem since the taggant used must be designed to endure the detonation process. A new taggant for use in explosives has been recently developed and named the `nuclear barcode'. The nuclear barcode tags explosives by adding low concentrations of eight different elements to the explosive, and then reads the tag from the post-blast residue using neutron activation analysis (NAA) to identify the elements and their concentrations. The nuclear barcode can be used to identify explosives after detonation by sampling the post-blast residue that is deposited due to incomplete reaction of the explosives. This method of tagging explosives creates an identifying taggant that survives detonation as NAA detects atomic nuclei as opposed to using any chemical or physical properties of the taggant that don't always survive the detonation process. Additional advantages this taggant method offers is ease of recovery of the taggant after detonation, and a total of 25.6 billion possible taggants as currently conceived, which enables the nuclear barcode to be used to tag individual batches of explosives. This paper describes the development of the nuclear barcode taggant system and its potential use in the explosives industry.

Broadband measurements of the sources of explosions at Stromboli Volcano, Italy

USGS Publications Warehouse

Chouet, B.; Saccorotti, G.; Dawson, P.; Martini, M.; Scarpa, R.; De Luca, G.; Milana, G.; Cattaneo, M.

1999-01-01

During September-October 1997, 21 three-component broadband seismometers were deployed on Stromboli Volcano at radial distances of 0.3-2.2 km from the active crater to investigate the source mechanisms of Strombolian explosions. In the 2-50 s band, the very-long period (VLP) signals associated with explosions are consistent with two stationary sources repeatedly activated in time. VLP particle motions are essentially linear and analyses of semblance and particle motions are consistent with a source centroid offset 300 m beneath and 300 m northwest of the active vents. Similar VLP waveforms are observed at all 21 stations, indicating that the seismograms are source-dominated. The VLP ground displacement response to each explosion may be qualitatively interpreted as: (1) pressurization of the conduit associated with the ascent of a slug of gas; (2) depressurization of the conduit in response to mass withdrawal during the eruption; and (3) repressurization of the conduit associated with the replenishment of the source with fluid. Copyright 1999 by the American Geophysical Union.

Coupled High Speed Imaging and Seismo-Acoustic Recordings of Strombolian Explosions at Etna, July 2014: Implications for Source Processes and Signal Inversions.

NASA Astrophysics Data System (ADS)

Taddeucci, J.; Del Bello, E.; Scarlato, P.; Ricci, T.; Andronico, D.; Kueppers, U.; Cannata, A.; Sesterhenn, J.; Spina, L.

2015-12-01

Seismic and acoustic surveillance is routinely performed at several persistent activity volcanoes worldwide. However, interpretation of the signals associated with explosive activity is still equivocal, due to both source variability and the intrinsically limited information carried by the waves. Comparison and cross-correlation of the geophysical quantities with other information in general and visual recording in particular is therefore actively sought. At Etna (Italy) in July 2014, short-lived Strombolian explosions ejected bomb- to lapilli-sized, molten pyroclasts at a remarkably repeatable time interval of about two seconds, offering a rare occasion to systematically investigate the seismic and acoustic fields radiated by this common volcanic source. We deployed FAMoUS (FAst, MUltiparametric Setup for the study of explosive activity) at 260 meters from the vents, recording more than 60 explosions in thermal and visible high-speed videos (50 to 500 frames per second) and broadband seismic and acoustic instruments (1 to 10000 Hz for the acoustic and from 0.01 to 30 Hz for the seismic). Analysis of this dataset highlights nonlinear relationships between the exit velocity and mass of ejecta and the amplitude and frequency of the acoustic signals. It also allows comparing different methods to estimate source depth, and to validate existing theory on the coupling of airwaves with ground motion.

Transition from phreatic to phreatomagmatic explosive activity of Zhupanovsky volcano (Kamchatka) in 2013-2016 due to volcanic cone collapse

NASA Astrophysics Data System (ADS)

Gorbach, Natalia; Plechova, Anastasiya; Portnyagin, Maxim

2017-04-01

Zhupanovsky volcano, situated 70 km north from Petropavlovsk-Kamchatsky city, resumed its activity in October 2013 [3]. In 2014 and in the first half of 2015, episodic explosions with ash plumes rising up to 6-8 km above sea level occurred on Priemish cone - one of four cones on the Zhupanovsky volcanic edifice [1]. In July 2015 after a series of seismic and explosive events, the southern sector of the active cone collapsed. The landslide and lahar deposits resulted from the collapse formed a large field on the volcano slopes [2]. In November 2015 and January-March 2016, a series of powerful explosions took place sending ash up to 8-10 km above sea level. No pure magmatic, effusive or extrusive, activity has been observed on Zhupanovsky in 2013-2016. We have studied the composition, morphology and textural features of ash particles produced by the largest explosive events of Zhupanovsky in the period from October 2013 to March 2016. The main components of the ash were found to be hydrothermally altered particles and lithics, likely originated by the defragmentation of rocks composing the volcanic edifice. Juvenile glass fragments occur in very subordinate quantities. The maximum amount of glass particles (up to 7%) was found in the ash erupted in January-March 2016, after the cone collapse. We suggest that the phreatic to phreatomagmatic explosive activity of Zhupanovsky volcano in 2013-2016 was initially caused by the intrusion of a new magma batch under the volcano. The intrusion and associated degassing of magma led to heating, overpressure and instability in the hydrothermal system of the volcano, causing episodic, predominantly phreatic explosions. Decompression of the shallow magmatic and hydrothermal system of the volcano due to the cone collapse in July 2015 facilitated a larger involvement of the magmatic component in the eruption and more powerful explosions. [1] Girina O.A. et al., 2016 Geophysical Research Abstracts Vol. 18, EGU2016-2101, doi: 10.13140/RG.2.1.5179.4001.[2] Gorbach N.V. et al., 2015. Bulletin of Kamchatka Regional Association "Educational-scientific Center". Earth Sciences. 3/27:5-11. [3] Samoilenko S.B. et al., 2014. Bulletin of Kamchatka Regional Association "Educational-scientific Center". Earth Sciences. 1/23:21-26.

30 CFR 57.4430 - Surface storage facilities.

Code of Federal Regulations, 2010 CFR

2010-07-01

....4430 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Fire Prevention... ignition sources to prevent fire or explosion; and (4) Vented or otherwise constructed to prevent...

30 CFR 56.4430 - Storage facilities.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Fire Prevention and... separated from ignition sources to prevent fire or explosion; and (4) Vented or otherwise constructed to...

14 CFR 420.5 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... activity. Net explosive weight (NEW) means the total weight, expressed in pounds, of explosive material or... azimuth and is positive in the downrange direction. The y-axis is positive to the left looking downrange...

Prediction of ground motion and dynamic stress change in Baekdusan (Changbaishan) volcano caused by a North Korean nuclear explosion

PubMed Central

Hong, Tae-Kyung; Choi, Eunseo; Park, Seongjun; Shin, Jin Soo

2016-01-01

Strong ground motions induce large dynamic stress changes that may disturb the magma chamber of a volcano, thus accelerating the volcanic activity. An underground nuclear explosion test near an active volcano constitutes a direct treat to the volcano. This study examined the dynamic stress changes of the magma chamber of Baekdusan (Changbaishan) that can be induced by hypothetical North Korean nuclear explosions. Seismic waveforms for hypothetical underground nuclear explosions at North Korean test site were calculated by using an empirical Green’s function approach based on a source-spectral model of a nuclear explosion; such a technique is efficient for regions containing poorly constrained velocity structures. The peak ground motions around the volcano were estimated from empirical strong-motion attenuation curves. A hypothetical M7.0 North Korean underground nuclear explosion may produce peak ground accelerations of 0.1684 m/s2 in the horizontal direction and 0.0917 m/s2 in the vertical direction around the volcano, inducing peak dynamic stress change of 67 kPa on the volcano surface and ~120 kPa in the spherical magma chamber. North Korean underground nuclear explosions with magnitudes of 5.0–7.6 may induce overpressure in the magma chamber of several tens to hundreds of kilopascals. PMID:26884136

Design and Fabrication of the Lithium Tokamak Experiment

NASA Astrophysics Data System (ADS)

Kozub, Thomas; Majeski, Richard; Kaita, Robert; Priniski, Craig; Zakharov, Leonid

2006-10-01

The design objective of the lithium tokamak experiment (LTX) is to investigate the equilibrium and stability of tokamak discharges with near-zero recycling. The construction of LTX incorporates the conversion of the existing current drive experiment (CDX) vessel into one with a nearly complete plasma facing surface of liquid lithium This paper will describe the design, fabrication, and installation activities required to convert CDX into LTX. The most significant new feature is the addition of a plasma facing liner on a shell that will be operated at 300 C to 400 C and covered with an evaporated layer of liquid lithium. The shell has been fabricated in-house from explosively bonded stainless steel on copper to a rather unique geometry to match the outer flux surface. Other significant device modifications include the construction of a new ohmic heating power system, rebuilding of the vacuum vessel, new lithium evaporators, additional diagnostics, modifications to the poloidal field coil geometry and their associated power supplies. Details on the progress of this conversion will be reported.

DESIGNING AN OPPORTUNITY FUEL WITH BIOMASS AND TIRE-DERIVED FUEL FOR COFIRING AT WILLOW ISLAND GENERATING STATION AND COFIRING SAWDUST WITH COAL AT ALBRIGHT GENERATING STATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

K. Payette; D. Tillman

During the period October 1, 2001--December 31, 2001, Allegheny Energy Supply Co., LLC (Allegheny) completed construction of the Willow Island cofiring project. This included completion of the explosion proof electrical wiring, the control system, and the control software. Procedures for system checkout, shakedown, and initial operation were initiated during this period. During this time period the 100-hour test of the Albright Generating Station cofiring facility was completed. The testing demonstrated that cofiring at the Albright Generating Station could reliably contribute to a ''4P Strategy''--reduction of SO{sub 2}, NO{sub x}, mercury, and greenhouse gas emissions over a significant load range. Duringmore » this period of time Allegheny Energy conducted facility tours of both Albright and Willow Island for the Biomass Interest Group of the Electric Power Research Institute. This report summarizes the activities associated with the Designer Opportunity Fuel program, and demonstrations at Willow Island and Albright Generating Stations. It details the completion of construction activities at the Willow Island site along with the 100-hr test at the Albright site.« less

Swarms of small earthquakes on Marapi Volcano, West Sumatra, Indonesia: are these precursors to explosion event?

NASA Astrophysics Data System (ADS)

Hidayat, D.; Patria, C.; Adi, S.; Gunawan, H.; Taisne, B.; Nurfiani, D.; Tan, C. T.

2016-12-01

Marapi Volcano's activity is characterized by Strombolian to small Vulcanian explosions with occasional VEI 2 producing tephra and pyroclastic flows. Currently in collaboration between Earth Observatory of Singapore (EOS) and Centre for Volcanology and Geological Hazard Mitigation (CVGHM) the volcano is seismically monitored with 7 broadband stations, and 2 short-period stations. In addition, we deployed 2 tiltmeters and an experimental soil CO2 sensor. These stations are telemetered by 5.8GHz radio to Marapi Observatory Post where data are archived and displayed for Marapi observers for their daily volcano activity monitoring work. We also archive the data in the EOS and CVGHM main offices. Data are being utilized by volcano scientists of CVGHM and researchers in both institutes as well as university students in and around them. We presented seismic earthquake sequences (swarm) prior to small explosion on Marapi in July 2016. These earthquakes are small, better identified after the deployment of seismic stations at summit, and located at depths < 1km near the volcano active vents. Similar swarms occurred prior to small explosions of Marapi. We also presented VLP-LP signals associated with an explosion which can be explained as volumetric change of sub-vertical crack at depth similar to the occurrence of small earthquake swarms. Our study attempt to understand the state of the volcano based on monitoring data and enable us to better estimate the hazards associated with future small explosions or eruptions.

A kilohertz approach to Strombolian-style eruptions

NASA Astrophysics Data System (ADS)

Taddeucci, Jacopo; Scarlato, Piergiorgio; Del Bello, Elisabetta; Gaudin, Damien

2015-04-01

Accessible volcanoes characterized by persistent, relatively mild Strombolian-style explosive activity have historically hosted multidisciplinary studies of eruptions. These studies, focused on geophysical signals preceding, accompanying, and following the eruptions, have provided key insights on the physical processes driving the eruptions. However, the dynamic development of the single explosions that characterize this style of activity remained somewhat elusive, due to the timescales involved (order of 0.001 seconds). Recent technological advances now allow recording and synchronizing different data sources on time scales relevant to the short timescales involved in the explosions. In the last several years we developed and implemented a field setup that integrates visual and thermal imaging with acoustic and seismic recordings, all synchronized and acquired at timescales of 100-10000 Hz. This setup has been developed at several active volcanoes. On the one hand, the combination of these different techniques provides unique information on the dynamics and energetics of the explosions, including the parameterization of individual ejection pulses within the explosions, the ejection and emplacement of pyroclasts and their coupling-decoupling with the gas phases, the different stages of development of the eruption jets, and their reflection in the associated acoustic and seismic signals. On the other hand, the gained information provides foundation for better understanding and interpreting the signals acquired, at lower sampling rates but routinely, from volcano monitoring networks. Perhaps even more important, our approach allows parameterizing differences and commonalities in the explosions from different volcanoes and settings.

Airblast Simulator Studies.

DTIC Science & Technology

1984-02-01

RAREFACTION WAVE ELIMINATOR CONSIDERATIONS 110 5.1 FLIP CALCULATIONS 110 5.2 A PASSIVE/ACTIVE RWE 118 6 DISTRIBUTED FUEL AIR EXPLOSIVES 120 REFERENCES 123 TA...conventional and distributed-charge fuel- air explosive charges used in a study of the utility of distributed charge FAE systems for blast simulation. The...limited investigation of distributed charge fuel air explosive configurations for blast simulator applications. During the course of this study

Bilateral Deficit in Explosive Force Production Is Not Caused by Changes in Agonist Neural Drive

PubMed Central

Buckthorpe, Matthew W.; Pain, Matthew T. G.; Folland, Jonathan P.

2013-01-01

Bilateral deficit (BLD) describes the phenomenon of a reduction in performance during synchronous bilateral (BL) movements when compared to the sum of identical unilateral (UL) movements. Despite a large body of research investigating BLD of maximal voluntary force (MVF) there exist a paucity of research examining the BLD for explosive strength. Therefore, this study investigated the BLD in voluntary and electrically-evoked explosive isometric contractions of the knee extensors and assessed agonist and antagonist neuromuscular activation and measurement artefacts as potential mechanisms. Thirteen healthy untrained males performed a series of maximum and explosive voluntary contractions bilaterally (BL) and unilaterally (UL). UL and BL evoked twitch and octet contractions were also elicited. Two separate load cells were used to measure MVF and explosive force at 50, 100 and 150 ms after force onset. Surface EMG amplitude was measured from three superficial agonists and an antagonist. Rate of force development (RFD) and EMG were reported over consecutive 50 ms periods (0–50, 50–100 and 100–150 ms). Performance during UL contractions was compared to combined BL performance to measure BLD. Single limb performance during the BL contractions was assessed and potential measurement artefacts, including synchronisation of force onset from the two limbs, controlled for. MVF showed no BLD (P = 0.551), but there was a BLD for explosive force at 100 ms (11.2%, P = 0.007). There was a BLD in RFD 50–100 ms (14.9%, P = 0.004), but not for the other periods. Interestingly, there was a BLD in evoked force measures (6.3–9.0%, P<0.001). There was no difference in agonist or antagonist EMG for any condition (P≥0.233). Measurement artefacts contributed minimally to the observed BLD. The BLD in volitional explosive force found here could not be explained by measurement issues, or agonist and antagonist neuromuscular activation. The BLD in voluntary and evoked explosive force might indicate insufficient stabiliser muscle activation during BL explosive contractions. PMID:23472091

Construction of New Energetics Buildings at the High Explosive Research and Development Facility (HERD) Final Environmental Assessment

DTIC Science & Technology

2003-06-01

fox and bobcat. On occasion the Florida black bear is found in the Sandhills ecological association (U.S. Air Force, 1995). 06/23/03 Construction...tropical air during the summer and continental polar air during the winter. There are two major seasons, summer and winter. Summer occurs from April...Department of Zoology and Wildlife Science and Alabama Cooperative Fish and Wildlife Research Unit, Auburn University, Auburn, AL. 30 August

Shock-treated Lunar Soil Simulant: Preliminary Assessment as a Construction Material

NASA Technical Reports Server (NTRS)

Boslough, Mark B.; Bernold, Leonhard E.; Horie, Yasuyuki

1992-01-01

In an effort to examine the feasibility of applying dynamic compaction techniques to fabricate construction materials from lunar regolith, preliminary explosive shock-loading experiments on lunar soil simulants were carried out. Analysis of our shock-treated samples suggests that binding additives, such as metallic aluminum powder, may provide the necessary characteristics to fabricate a strong and durable building material (lunar adobe) that takes advantage of a cheap base material available in abundance: lunar regolith.

29 CFR 1926.911 - Misfires.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 29 Labor 8 2011-07-01 2011-07-01 false Misfires. 1926.911 Section 1926.911 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Blasting and the Use of Explosives § 1926.911 Misfires. (a...

29 CFR 1926.911 - Misfires.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 29 Labor 8 2013-07-01 2013-07-01 false Misfires. 1926.911 Section 1926.911 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Blasting and the Use of Explosives § 1926.911 Misfires. (a...

29 CFR 1926.911 - Misfires.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 29 Labor 8 2014-07-01 2014-07-01 false Misfires. 1926.911 Section 1926.911 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Blasting and the Use of Explosives § 1926.911 Misfires. (a...

29 CFR 1926.911 - Misfires.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 8 2010-07-01 2010-07-01 false Misfires. 1926.911 Section 1926.911 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Blasting and the Use of Explosives § 1926.911 Misfires. (a...

29 CFR 1926.911 - Misfires.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 29 Labor 8 2012-07-01 2012-07-01 false Misfires. 1926.911 Section 1926.911 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Blasting and the Use of Explosives § 1926.911 Misfires. (a...

30 CFR 18.34 - Motors.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design Requirements § 18.34 Motors. Explosion-proof electric motor assemblies intended for use in approved equipment in underground... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Motors. 18.34 Section 18.34 Mineral Resources...

[A case of carbon monoxide poisoning by explosion of coal mine presenting as visual agnosia: re-evaluation after 40 years].

PubMed

Takaiwa, Akiko; Yamashita, Kenichiro; Nomura, Takuo; Shida, Kenshiro; Taniwaki, Takayuki

2005-11-01

We re-evaluated a case of carbon monoxide poisoning presenting as visual agnosia who had been injured by explosion of Miike-Mikawa coal mine 40 years ago. In an early stage, his main neuropsychological symptoms were visual agnosia, severe anterograde amnesia, alexia, agraphia, constructional apraxia, left hemispatial neglect and psychic paralysis of gaze, in addition to pyramidal and extra pyramidal signs. At the time of re-evaluation after 40 years, he still showed visual agnosia associated with agraphia and constructional apraxia. Concerning visual agnosia, recognition of the real object was preserved, while recognition of object photographs and picture was impaired. Thus, this case was considered to have picture agnosia as he could not recognize the object by pictorial cues on the second dimensional space. MRI examination revealed low signal intensity lesions and cortical atrophy in the bilateral parieto-occipital lobes on T1-weighted images. Therefore, the bilateral parieto-occipital lesions are likely to be responsible for his picture agnosia.

Luminescent Li-based metal-organic framework tailored for the selective detection of explosive nitroaromatic compounds: direct observation of interaction sites.

PubMed

Kim, Tae Kyung; Lee, Jae Hwa; Moon, Dohyun; Moon, Hoi Ri

2013-01-18

A luminescent lithium metal-organic framework (MOF) is constructed from the solvothermal reaction of Li(+) and a well-designed organic ligand, bis(4-carboxyphenyl)-N-methylamine (H(2)CPMA). A Li-based MOF can detect an explosive aromatic compound containing nitro groups as an explosophore, by showing a dramatic color change with concurrent luminescence quenching in the solid state. The detection sites are proven directly through single-crystal-to-single-crystal transformations, which show strong interactions between the aromatic rings of the electron-rich CPMA(2-) molecules and the electron-deficient nitrobenzene.

Wave run-up of a possible Anak-Krakatau tsunami on planned and optimized Jakarta Sea Dike

NASA Astrophysics Data System (ADS)

Badriana, M. R.; Bachtiar, H.; Adytia, D.; Sembiring, L.; Andonowati, van Groesen, E.

2017-07-01

The infrastructural plans in the Jakarta Bay to reduce risks of flooding in Jakarta city comprise a large Sea Dike that encloses a retention lake. Part of the planned dike has the shape of the iconic Garuda bird. This paper shows that if in the future an explosion of Anak Krakatau will occur with strength 1/4th of the original Karkatau 1883 explosion, wave crests of 11m and troughs of 6m may collide against the bird's head. As an alternative example, a more optimized design of the dike is constructed that reduces the maximal wave effects considerably.

Methane Explosion Mitigation in Coal Mines by Water Mist

NASA Astrophysics Data System (ADS)

Chikhradze, Nikoloz; Mataradze, Edgar; Chikhradze, Mikheil; Krauthammer, Ted; Mansurov, Zulkhair; Alyiev, Erhan

2017-12-01

Statistics shows that the majority of accidents with fatal outcome are caused by methane and/or coal dust explosion. This leads to assume that contemporary counter-explosion systems of various designs cannot be considered effective. Considering the growing threat of methane explosion in the coming years along with the development of deeper levels, the improvement of a system for protecting people in underground opening appears urgent. This paper focuses on technical solutions to be used in designing a protective system for minimizing the consequences of methane explosions in coalmines. The new protective system consists of three main modules: i) a high-speed shock wave suppression section; ii) a suppression section with a long-term action and iii) a system activating device. The shock wave suppressor contains a 200 litre volume water tank with a built-in gas generator and nozzles. It is activated after 12ms from the blast moment, the duration of discharge is 40 s. The suppression section with a long-term action contains a 2000 litre volume water tank, a high-pressure pump, a hydraulic accumulator, solenoid valves, and a system of pipes with built-in nozzles. It is activated after 4 s from the blast moment, the duration of discharge is 8 min. The activation device includes a detection block containing sensors, an emergency signal generation module, a signal transmission module, a signal receiving module and a power supply module. The system operates in a waiting mode and activates immediately upon the receipt of the start signal generated by the detector. The paper also addresses the preliminary results of the system prototype testing in the tunnel.

Development of a technique using MCNPX code for determination of nitrogen content of explosive materials using prompt gamma neutron activation analysis method

NASA Astrophysics Data System (ADS)

Nasrabadi, M. N.; Bakhshi, F.; Jalali, M.; Mohammadi, A.

2011-12-01

Nuclear-based explosive detection methods can detect explosives by identifying their elemental components, especially nitrogen. Thermal neutron capture reactions have been used for detecting prompt gamma 10.8 MeV following radioactive neutron capture by 14N nuclei. We aimed to study the feasibility of using field-portable prompt gamma neutron activation analysis (PGNAA) along with improved nuclear equipment to detect and identify explosives, illicit substances or landmines. A 252Cf radio-isotopic source was embedded in a cylinder made of high-density polyethylene (HDPE) and the cylinder was then placed in another cylindrical container filled with water. Measurements were performed on high nitrogen content compounds such as melamine (C3H6N6). Melamine powder in a HDPE bottle was placed underneath the vessel containing water and the neutron source. Gamma rays were detected using two NaI(Tl) crystals. The results were simulated with MCNP4c code calculations. The theoretical calculations and experimental measurements were in good agreement indicating that this method can be used for detection of explosives and illicit drugs.

Nearby Galaxy is a Hotbed of Star Birth Activity

NASA Technical Reports Server (NTRS)

2004-01-01

This new image taken with NASA's Hubble Space Telescope (HST) is of the nearby dwarf galaxy NGC 1569. This galaxy is a hotbed of vigorous star birth activity which blows huge bubbles that riddle its main body. The bubble structure is sculpted by the galactic super-winds and outflows caused by a colossal input of energy from collective supernova explosions that are linked with a massive episode of star birth. The bubbles seen in this image are made of hydrogen gas that glows when hit by the fierce wind and radiation from hot young stars and is racked by supernova shocks. Its 'star factories' are also manufacturing brilliant blue star clusters. NGC 1569 had a sudden onset of star birth about 25 million years ago, which subsided about the time the very earliest human ancestors appeared on Earth. The Marshall Space Flight Center had responsibility for the design, development, and construction of the HST.

Evaluation of various organic fertilizer substrates and hydraulic retention times for enhancing anaerobic degradation of explosives-contaminated groundwater while using constructed wetlands at the Milan Army Ammunition Plant, Milan, Tennessee. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Behrends, L.L.; Almond, R.A.; Kelly, D.A.

1998-05-01

This document describes studies conducted at the Milan Army Ammunition Plant (MAAP) to improve the design, operation, and cost of gravel-based anaerobic cells when phytoremediating explosives-contaminated groundwater. To conduct this study, small-scale anaerobic test cells were used to determine: (1) If the hydraulic retention time of a large demonstration-scale anaerobic cell at MAAP could be reduced, and (2) if other carbon sources could be used as an anaerobic feedstock. The study results indicated that: (1) The existing anaerobic cell`s 7.5-day retention time should not be reduced since residual explosive by-products were present in the effluent of treatments with a 3.5-daymore » retention time. (2) Daily application of a relatively soluble substrate, such as molasses syrup, will provide better explosives removal than periodic application of less soluble substrates like milk replacement starter and sewage sludge. (3) Molasses syrup could be, and should be, used as a substitute for milk replacement power. The recommendation to use molasses syrup was based on: (1) The lower cost of molasses syrup as compared to milk replacement starter, (2) molasses syrup`s higher solubility (which makes it easier to apply), and (3) molasses syrup`s ability to provide enhanced explosives removal.« less

Anaerobic biotransformation of explosives in aquifer slurries amended with ethanol and propylene glycol.

PubMed

Adrian, Neal R; Arnett, Clint M

2007-01-01

Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), and 2,4,6-trinitrotoluene (TNT) are explosives that are frequently found as environmental contaminants on military installations. Hydrogen has been shown to support the anaerobic transformation of these explosives. We investigated ethanol and propylene glycol as electron donors for providing syntrophically produced H2 for stimulating the anaerobic biodegradation of explosives in contaminated soil. The study was conducted using anoxic microcosms constructed with slurries of the contaminated soil and groundwater. The addition of 5mM ethanol and propylene glycol enhanced the biodegradation of RDX and HMX relative to the control bottles. Ethanol was depleted within about 20 days, resulting in the transient formation of hydrogen, acetate, and methane. The hydrogen headspace concentration increased from 8 ppm to 1838 ppm before decreasing to background concentrations. Propylene glycol was completely degraded after 15 days, forming hydrogen, propionate, and acetate as end-products. The hydrogen headspace concentrations increased from 56 ppm to 628 ppm before decreasing to background concentrations. No methane formation was observed during the incubation period of 48 days. Our findings indicate the addition of ethanol and propylene to the aquifer slurries increased the hydrogen concentrations and enhanced the biotransformation of RDX and HMX in the explosive-contaminated soil.

Experimental investigation on the energy deposition and expansion rate under the electrical explosion of aluminum wire in vacuum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shi, Zongqian; Wang, Kun; Shi, Yuanjie

Experimental investigations on the electrical explosion of aluminum wire using negative polarity current in vacuum are presented. Current pulses with rise rates of 40 A/ns, 80 A/ns, and 120 A/ns are generated for investigating the influence of current rise rate on energy deposition. Experimental results show a significant increase of energy deposition into the wire before the voltage breakdown with the increase of current rise rate. The influence of wire dimension on energy deposition is investigated as well. Decreasing the wire length allows more energy to be deposited into the wire. The energy deposition of a 0.5 cm-long wire explosion ismore » ∼2.5 times higher than the energy deposition of a 2 cm-long wire explosion. The dependence of the energy deposition on wire diameter demonstrates a maximum energy deposition of 2.7 eV/atom with a diameter of ∼18 μm. Substantial increase in energy deposition is observed in the electrical explosion of aluminum wire with polyimide coating. A laser probe is applied to construct the shadowgraphy, schlieren, and interferometry diagnostics. The morphology and expansion trajectory of exploding products are analyzed based on the shadowgram. The interference phase shift is reconstructed from the interferogram. Parallel dual wires are exploded to estimate the expansion velocity of the plasma shell.« less

TIME-SEQUENCED X-RAY OBSERVATION OF A THERMAL EXPLOSION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tringe, J. W.; Molitoris, J. D.; Kercher, J. R.

The evolution of a thermally-initiated explosion is studied using a multiple-image x-ray system. HMX-based PBX 9501 is used in this work, enabling direct comparison to recently-published data obtained with proton radiography [1]. Multiple x-ray images of the explosion are obtained with image spacing of ten microseconds or more. The explosion is simultaneously characterized with a high-speed camera using an interframe spacing of 11 mus. X-ray and camera images were both initiated passively by signals from an embedded thermocouple array, as opposed to being actively triggered by a laser pulse or other external source. X-ray images show an accelerating reacting frontmore » within the explosive, and also show unreacted explosive at the time the containment vessel bursts. High-speed camera images show debris ejected from the vessel expanding at 800-2100 m/s in the first tens of mus after the container wall failure. The effective center of the initiation volume is about 6 mm from the geometric center of the explosive.« less

Explosive Deep Sea Volcanism Produces Composite Volcanoes (Stratocones) with Predominantly Diffuse Flow Hydrothermal Ecosystems

NASA Astrophysics Data System (ADS)

Rubin, K. H.; Chadwick, W. C.; Embley, R. W.; Butterfield, D. A.

2018-05-01

Newly-discovered extensive explosive deep sea volcanism produces distinct stratovolcano structures and physical rock characteristics, and host primarily diffuse flow hydrothermal activity, unlike focused flow systems at effusive submarine volcanoes.

Design of a novel instrument for active neutron interrogation of artillery shells.

PubMed

Bélanger-Champagne, Camille; Vainionpää, Hannes; Peura, Pauli; Toivonen, Harri; Eerola, Paula; Dendooven, Peter

2017-01-01

The most common explosives can be uniquely identified by measuring the elemental H/N ratio with a precision better than 10%. Monte Carlo simulations were used to design two variants of a new prompt gamma neutron activation instrument that can achieve this precision. The instrument features an intense pulsed neutron generator with precise timing. Measuring the hydrogen peak from the target explosive is especially challenging because the instrument itself contains hydrogen, which is needed for neutron moderation and shielding. By iterative design optimization, the fraction of the hydrogen peak counts coming from the explosive under interrogation increased from [Formula: see text]% to [Formula: see text]% (statistical only) for the benchmark design. In the optimized design variants, the hydrogen signal from a high-explosive shell can be measured to a statistics-only precision better than 1% in less than 30 minutes for an average neutron production yield of 109 n/s.

Design of a novel instrument for active neutron interrogation of artillery shells

PubMed Central

Vainionpää, Hannes; Peura, Pauli; Toivonen, Harri; Eerola, Paula; Dendooven, Peter

2017-01-01

The most common explosives can be uniquely identified by measuring the elemental H/N ratio with a precision better than 10%. Monte Carlo simulations were used to design two variants of a new prompt gamma neutron activation instrument that can achieve this precision. The instrument features an intense pulsed neutron generator with precise timing. Measuring the hydrogen peak from the target explosive is especially challenging because the instrument itself contains hydrogen, which is needed for neutron moderation and shielding. By iterative design optimization, the fraction of the hydrogen peak counts coming from the explosive under interrogation increased from 53-7+7% to 74-10+8% (statistical only) for the benchmark design. In the optimized design variants, the hydrogen signal from a high-explosive shell can be measured to a statistics-only precision better than 1% in less than 30 minutes for an average neutron production yield of 109 n/s. PMID:29211773

Detecting Earthquakes--Part 2.

ERIC Educational Resources Information Center

Isenberg, C.; And Others

1983-01-01

Basic concepts associated with seismic wave propagation through the earth and the location of seismic events were explained in part 1 (appeared in January 1983 issue). This part focuses on the construction of a student seismometer for detecting earthquakes and underground nuclear explosions anywhere on the earth's surface. (Author/JN)

30 CFR 22.7 - Specific requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... APPROVAL OF MINING PRODUCTS PORTABLE METHANE DETECTORS § 22.7 Specific requirements. (a) Design. In the... explosion hazard—(1) Detectors. Detectors shall be constructed so that they will not cause external... diameter and are of reasonably thick glass. (4) Battery. If the detector is equipped with a battery, it...

30 CFR 22.7 - Specific requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... APPROVAL OF MINING PRODUCTS PORTABLE METHANE DETECTORS § 22.7 Specific requirements. (a) Design. In the... explosion hazard—(1) Detectors. Detectors shall be constructed so that they will not cause external... diameter and are of reasonably thick glass. (4) Battery. If the detector is equipped with a battery, it...

30 CFR 22.7 - Specific requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... APPROVAL OF MINING PRODUCTS PORTABLE METHANE DETECTORS § 22.7 Specific requirements. (a) Design. In the... explosion hazard—(1) Detectors. Detectors shall be constructed so that they will not cause external... diameter and are of reasonably thick glass. (4) Battery. If the detector is equipped with a battery, it...

30 CFR 22.7 - Specific requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... APPROVAL OF MINING PRODUCTS PORTABLE METHANE DETECTORS § 22.7 Specific requirements. (a) Design. In the... explosion hazard—(1) Detectors. Detectors shall be constructed so that they will not cause external... diameter and are of reasonably thick glass. (4) Battery. If the detector is equipped with a battery, it...

Risk assessment for stonecutting enterprises Accidental risks in the course of petroleum production and stone extraction

NASA Astrophysics Data System (ADS)

Aleksandrova, A. J.; Timofeeva, S. S.

2018-01-01

The paper is devoted to the assessment of accidental risks occurring at the works engaged in stone extracting and petroleum production. Two basic kinds of accidents common for stone extracting and petroleum production have been chosen to be discussed in the part under consideration. The most dangerous accidental situation characteristic for a stone milling line is an unsanctioned explosion, UE, of blasting agents used for the development of stone deposits. The analysis of a risk occurrence in certain accidental situations is to be carried out. With reference to petroleum extraction, a combustibles and lubricants (C & L) explosion is the most dangerous of characteristic accidental situations. To reveal the most probable causes of accidental situations to be realized, a graph of cause and effect relations has been constructed for each of the accidental situations most probable causes to real situation of an accident. Disasters of a natural origin are the most probable causes of unsanctioned explosions at the deposits of stone raw materials. Technology related natural disasters are the most probable causes of unsanctioned explosions to be realized at multiple well platforms engaged in petroleum production.

Velocity Model Using the Large-N Seismic Array from the Source Physics Experiment (SPE)

NASA Astrophysics Data System (ADS)

Chen, T.; Snelson, C. M.

2016-12-01

The Source Physics Experiment (SPE) is a multi-institutional, multi-disciplinary project that consists of a series of chemical explosions conducted at the Nevada National Security Site (NNSS). The goal of SPE is to understand the complicated effect of geological structures on seismic wave propagation and source energy partitioning, develop and validate physics-based modeling, and ultimately better monitor low-yield nuclear explosions. A Large-N seismic array was deployed at the SPE site to image the full 3D wavefield from the most recent SPE-5 explosion on April 26, 2016. The Large-N seismic array consists of 996 geophones (half three-component and half vertical-component sensors), and operated for one month, recording the SPE-5 shot, ambient noise, and additional controlled-sources (a large hammer). This study uses Large-N array recordings of the SPE-5 chemical explosion to develop high resolution images of local geologic structures. We analyze different phases of recorded seismic data and construct a velocity model based on arrival times. The results of this study will be incorporated into the large modeling and simulation efforts as ground-truth further validating the models.

The aftermath of an industrial disaster.

PubMed

Elklit, A

1997-01-01

An explosion in a Danish supertanker under construction in 1994 caused the death of six workers and injured 15. Six months later 270 workers took part in this study, which analyses the relationships between objective stressors, the workers' own feelings and the reactions of their families after the explosion together with training, attitude to the workplace, general out-look, and received crisis help. Traumatisation, coping style and crisis support was assessed via the Impact of Event Scale (IES), the Coping Styles Questionnaire (CSQ) and the Crisis Support Scale (CSS). Emotionally, workers and their families were strongly affected by the explosion. The IES-score was 17.6 and the invasion score 9.1. The degree of traumatisation was higher in the group who had an 'audience position' than in the group who was directly hit by the explosion. Training in rescue work did not protect against adverse effects. Rescue work had a strong impact on the involved. Social support was a significant factor, that seems to buffer negative effects. High level of social integration, effective leadership in the situation, and professional crisis intervention characterised the disaster situation. All the same, 41 per cent of the workers reached the caseness criteria by Horowitz (IES > or = 19).

SWAN - Detection of explosives by means of fast neutron activation analysis

NASA Astrophysics Data System (ADS)

Gierlik, M.; Borsuk, S.; Guzik, Z.; Iwanowska, J.; Kaźmierczak, Ł.; Korolczuk, S.; Kozłowski, T.; Krakowski, T.; Marcinkowski, R.; Swiderski, L.; Szeptycka, M.; Szewiński, J.; Urban, A.

2016-10-01

In this work we report on SWAN, the experimental, portable device for explosives detection. The device was created as part of the EU Structural Funds Project "Accelerators & Detectors" (POIG.01.01.02-14-012/08-00), with the goal to increase beneficiary's expertise and competencies in the field of neutron activation analysis. Previous experiences and budged limitations lead toward a less advanced design based on fast neutron interactions and unsophisticated data analysis with the emphasis on the latest gamma detection and spectrometry solutions. The final device has been designed as a portable, fast neutron activation analyzer, with the software optimized for detection of carbon, nitrogen and oxygen. SWAN's performance in the role of explosives detector is elaborated in this paper. We demonstrate that the unique features offered by neutron activation analysis might not be impressive enough when confronted with practical demands and expectations of a generic homeland security customer.

Standoff laser-based spectroscopy for explosives detection

NASA Astrophysics Data System (ADS)

Gaft, M.; Nagli, L.

2007-10-01

Real time detection and identification of explosives at a standoff distance is a major issue in efforts to develop defense against so-called Improvised Explosive Devices (IED). It is recognized that the only technique, which is potentially capable to standoff detection of minimal amounts of explosives is laser-based spectroscopy. LDS activity is based on a combination of laser-based spectroscopic methods with orthogonal capabilities. Our technique belongs to trace detection, namely to its micro-particles variety. It is based on commonly held belief that surface contamination was very difficult to avoid and could be exploited for standoff detection. We has applied optical techniques including gated Raman and time-resolved luminescence spectroscopy for detection of main explosive materials, both factory and homemade. We developed and tested a Raman system for the field remote detection and identification of minimal amounts of explosives on relevant surfaces at a distance of up to 30 meters.

Air Force construction automation/robotics

NASA Technical Reports Server (NTRS)

Nease, AL; Dusseault, Christopher

1994-01-01

The Air Force has several unique requirements that are being met through the development of construction robotic technology. The missions associated with these requirements place construction/repair equipment operators in potentially harmful situations. Additionally, force reductions require that human resources be leveraged to the maximum extent possible and that more stringent construction repair requirements push for increased automation. To solve these problems, the U.S. Air Force is undertaking a research and development effort at Tyndall AFB, FL to develop robotic teleoperation, telerobotics, robotic vehicle communications, automated damage assessment, vehicle navigation, mission/vehicle task control architecture, and associated computing environment. The ultimate goal is the fielding of robotic repair capability operating at the level of supervised autonomy. The authors of this paper will discuss current and planned efforts in construction/repair, explosive ordnance disposal, hazardous waste cleanup, fire fighting, and space construction.

10 CFR 50.55 - Conditions of construction permits, early site permits, combined licenses, and manufacturing...

Code of Federal Regulations, 2014 CFR

2014-01-01

..., combined licenses, and manufacturing licenses. 50.55 Section 50.55 Energy NUCLEAR REGULATORY COMMISSION... experimental nature of the facility or fire, flood, explosion, strike, sabotage, domestic violence, enemy... submitted to the Document Control Desk, U.S. Nuclear Regulatory Commission, by an appropriate method listed...

10 CFR 50.55 - Conditions of construction permits, early site permits, combined licenses, and manufacturing...

Code of Federal Regulations, 2012 CFR

2012-01-01

..., combined licenses, and manufacturing licenses. 50.55 Section 50.55 Energy NUCLEAR REGULATORY COMMISSION... experimental nature of the facility or fire, flood, explosion, strike, sabotage, domestic violence, enemy... submitted to the Document Control Desk, U.S. Nuclear Regulatory Commission, by an appropriate method listed...

10 CFR 50.55 - Conditions of construction permits, early site permits, combined licenses, and manufacturing...

Code of Federal Regulations, 2013 CFR

2013-01-01

..., combined licenses, and manufacturing licenses. 50.55 Section 50.55 Energy NUCLEAR REGULATORY COMMISSION... experimental nature of the facility or fire, flood, explosion, strike, sabotage, domestic violence, enemy... submitted to the Document Control Desk, U.S. Nuclear Regulatory Commission, by an appropriate method listed...

30 CFR 7.96 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... diesel engine with an intake system, exhaust system, and a safety shutdown system installed. Dry exhaust.... A system connected to the outlet of the diesel engine which includes, but is not limited to, the... constructed that flame or sparks from the diesel engine cannot propagate an explosion of a flammable mixture...

30 CFR 7.96 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... diesel engine with an intake system, exhaust system, and a safety shutdown system installed. Dry exhaust.... A system connected to the outlet of the diesel engine which includes, but is not limited to, the... constructed that flame or sparks from the diesel engine cannot propagate an explosion of a flammable mixture...

A systematic study of the explosion energy issue in core collapse supernova theory

NASA Astrophysics Data System (ADS)

Yamamoto, Yu

2016-06-01

Massive stars with main sequence masses greater than 8 solar mass (Msun) the main target of CCSNe researches. According to initial mass function (IMF) they occupy about 15As a matter of fact, supernova theorists have failed to reproduce this energetic stellar explosion for about a half century because micro and macro physics are highly complex and are mutual influenced. The theoretical investigation of the explosion mechanism is based on numerical simulations, which will ultimately require computational sources of exsa scales. With recent remarkable developments both in hardware and software, however, more realistic physics are incorporated and research group are beginning to overcome the difficulties, reporting successful explosions in their numerical models. The successful is still partial, unfortunately, since in the most of the cases the explosion energy hardly reaches the typical value (10^51erg). What is worse other groups found no explosion for almost same setups. The robust explosion mechanism has not yet been ascertained and is still a remaining issue. The purpose of this paper is to study how far our understanding of "neutrino heating mechanism", the current paradigm, has reached, or put another way, to expose what kind of physics are still missing to explain observations , such as explosion energy and nickel mass. As already remarked the physics in CCSNe are quite complicated with extremely high Reynolds number, highly uncertain equation of state (EOS) at supra-nuclear densities, copious neutrinos not in thermal nor chemical equilibrium with matter normally. I believe that it is justified to devote a somewhat large number of pages to the introduction. It will be also helpful for understanding the motivation of this paper. Starting with evidence from supernova light curves I will then move to the basics idea of neutrino heating mechanism and summarize some recent developments in various micro and macro physics. Key factors in the theory of massive-star evolutions are also illuminated in the introduction. Other important ingredients that are not directly related with the thesis, such as numerical treatments of neutrino transport, are given in appendices. To find the missing pieces of the current CCSNe theory, I employed an experimental way instead of running "realistic" simulations. In fact, I conducted experimental computations systematically so as to reveal (1) what is the necessary condition of the canonical explosion energy (2) what is the dominant contribution to the explosion energy (3) when the explosion energy is settled to the final value, and, finally, (4) features in pre-explosion structure of the progenitor are critical for the explosion energy. In this paper I paid particular attention to nuclear energies released in association with the production of various elements up to A 56, which are likely to contribute to the energetics of CCSNe. I performed multi-dimension hydrodynamic simulations that can also handle the evolution of elements in both nuclear statistical equilibrium (NSE) and non-equilibrium, taking particular care of transition from one to the other. We take a multi-step strategy: collapse, shock revival and the subsequent evolution until the settlement of explosion energy are treated separately and consecutively; the collapse phase is calculated under spherical symmetry to obtain mass accretion histories for different progenitors; in so doing, the inner part of the core is removed and replaced with the artificial inner boundary; the second phase treats shock revival; we construct steady accretion flows through the stalled shock wave on to the proto neutron star; using these configurations as initial conditions for 1D and 2D simulations, we determine the critical neutrino luminosities for shock revival; the evolutions that follow the shock revival are computed in the last phase, with the mass accretion histories obtained in the first phase being taken into account. In the first of two studies done for the thesis we used a single progenitor of 15Msun provided by a realistic stellar evolution calculation and studied the post-shock revival evolutions, changing the time of shock revival. We run seven 1D and five 2D models. In the second exploration, on the other hand, we pay attention to the progenitor dependence of the dynamics. Instead of using progenitor models from realistic stellar evolution calculations, I construct six pre-collapse models with different masses of Fe core and Si+S layer assuming entropy and electron fraction distributions and varying rather arbitrarily the parameters included. Unlike in the first study, we did not specify the shock revival time explicitly but gave the neutrino luminosity in this study. The explosion energy and nickel mass are calculated for eighteen 1D and eight 2D models, respectively. The two studies demonstrate that early explosions are necessary for strong explosions. It is also found that nuclear recombination energy is a major contributor to the explosion energy which is settled to the final value in 500ms whereas the nickel mass needs much longer times to reach the final value, particularly in 2D. Since the nickel tends to be overproduced in early explosions, enhanced fallbacks in multi-dimensional hydrodynamics seem to be crucial to reproduce the observed values of nickel mass and explosion energy simultaneously. As for the progenitor dependence, we found that light cores with relatively high entropies seem to be favorable for reproducing the canonical explosion by the neutrino heating mechanism. It is interesting that the explosion energy is strongly correlated with the mass accretion rate at shock revival regardless of the spatial dimensions.

SO2 Emissions at Semeru Volcano, Indonesia: Characterization and Quantification of Persistent and Periodic Explosive Activity.

NASA Astrophysics Data System (ADS)

Smekens, J. F.; Clarke, A. B.; Burton, M. R.; Harijoko, A.; Wibowo, H.

2014-12-01

We present the first measurements of SO2 emissions at Semeru volcano, Indonesia, using an SO2 camera. Activity at Semeru is characterized by quiescent degassing interspersed with short-lived explosive events with low ash burden. The interval between explosions was measured at 32.1±15.7 minutes in a webcam survey of the volcano between the months of June and December 2013. We distinguish between two types of events: shorter events (type I: ~5 mins duration) with emissions returning quickly to baseline levels, and longer events (type II: ~15 mins duration) often showing multiple pulses and a longer period of increased emissions before a return to quiescent levels. Type I events represent >90% of the activity and release an average of 200-450 kg of SO2 per event. The single type II event we documented with the SO2 camera released a total of 1300 kg of SO2. We estimate the daily average emissions of Semeru to be 21-60 t d-1 of SO2, amounting to a yearly output of 7.5-22 Gg (7,500 - 22,000 metric tons), with 35-60% released during explosive events. The time series patterns of degassing are consistent with the existence of a viscous plug at the top of the conduit, causing accumulation and pressurization of the magma to produce the explosive events.

Quantification of Rock Damage from Small Explosions and Its Effect on Shear-Wave Generation

DTIC Science & Technology

2009-06-15

close to a nearby cell /radio tower and the active quarry wall to detonate our planned 400 lb explosions. Core drilling at an alternative test site...Figure ) was conducted further away from the active quarry wall and a nearby cell /radio tower. The alternative site would be far enough away from...returned into the original location (Figure ). In order to reduce the projected ground vibrations at the cell /radio tower and high wall of the active

Thermochemical properties of nanometer CL-20 and PETN fabricated using a mechanical milling method

NASA Astrophysics Data System (ADS)

Song, Xiaolan; Wang, Yi; An, Chongwei

2018-06-01

2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) and pentaerythritol tetranitrate (PETN), with mean sizes of 73.8 nm and 267.7 nm, respectively, were fabricated on a high-energy ball-mill. Scanning electron microscope (SEM) analysis was used to image the micron-scale morphology of nano-explosives, and the particle size distribution was calculated using the statistics of individual particle sizes obtained from the SEM images. Analyses, such as X-ray diffractometer (XRD), infrared spectroscopy (IR), and X-ray photoelectron spectroscopy (XPS), were also used to confirm whether the crystal phase, molecular structure, and surface elements changed after a long-term milling process. The results were as expected. Thermal analysis was performed at different heating rates. Parameters, such as the activation energy (ES), activation enthalpy (ΔH≠), activation free energy (ΔG≠), activation entropy (ΔS≠), and critical temperature of thermal explosion (Tb), were calculated to determine the decomposition courses of the explosives. Moreover, the thermal decomposition mechanisms of nano CL-20 and nano PETN were investigated using thermal-infrared spectrometry online (DSC-IR) analysis, by which their gas products were also detected. The results indicated that nano CL-20 decomposed to CO2 and N2O and that nano PETN decayed to NO2, which implied a remarkable difference between the decomposition mechanisms of the two explosives. In addition, the mechanical sensitivities of CL-20 and PETN were tested, and the results revealed that nano-explosives were more insensitive than raw ones, and the possible mechanism for this was discussed. Thermal sensitivity was also investigated with a 5 s bursting point test, from which the 5 s bursting point (T5s) and the activation of the deflagration were obtained.

Development of a contrast phantom for active millimeter-wave imaging systems

NASA Astrophysics Data System (ADS)

Barber, Jeffrey; Weatherall, James C.; Brauer, Carolyn S.; Smith, Barry T.

2011-06-01

As the development of active millimeter wave imaging systems continues, it is necessary to validate materials that simulate the expected response of explosives. While physics-based models have been used to develop simulants, it is desirable to image both the explosive and simulant together in a controlled fashion in order to demonstrate success. To this end, a millimeter wave contrast phantom has been created to calibrate image grayscale while controlling the configuration of the explosive and simulant such that direct comparison of their respective returns can be performed. The physics of the phantom are described, with millimeter wave images presented to show successful development of the phantom and simulant validation at GHz frequencies.

Optical ordnance system for use in explosive ordnance disposal activities

NASA Technical Reports Server (NTRS)

Merson, J. A.; Salas, F. J.; Helsel, F.M.

1994-01-01

A portable hand-held solid state rod laser system and an optically-ignited detonator have been developed for use in explosive ordnance disposal (EOD) activities. Laser prototypes from Whittaker Ordnance and Universal Propulsion have been tested and evaluated. The optical detonator contains 2-(5 cyanotetrazolato) pentaamine cobalt(III) perchlorate (CP) as the DDT column and the explosive Octahydro- 1,3,5,7 - tetrazocine (HMX) as the output charge. The laser is designed to have an output of 150 mJ in a 500 microsecond pulse. This output allows firing through 2000 meters of optical fiber. The detonator can also be ignited with a portable laser diode source through a shorter length of fiber.

Physical structure changes of solid medium by steam explosion sterilization.

PubMed

Zhao, Zhi-Min; Wang, Lan; Chen, Hong-Zhang

2016-03-01

Physical structure changes of solid medium were investigated to reveal effects of steam explosion sterilization on solid-state fermentation (SSF). Results indicated that steam explosion changed the structure of solid medium at both molecular and three-dimensional structural levels, which exposed hydrophilic groups and enlarged pores and cavities. It was interesting to find that pores where capillary water located were the active sites for SSF, due to the close relationship among capillary water relaxation time, specific surface area and fermentation performance. Therefore, steam explosion sterilization increased the effective contact area for microbial cells on solid medium, which contributed to improving SSF performance. Combined with the previous research, mechanisms of SSF improvement by steam explosion sterilization contained both chemical and physical effects. Copyright © 2015 Elsevier Ltd. All rights reserved.

Fatal and non-fatal injuries due to intentional explosions in Nepal, 2008-2011: analysis of surveillance data

PubMed Central

2013-01-01

Background Nepal is one of the post-conflict countries affected by violence from explosive devices. We undertook this study to assess the magnitude of injuries due to intentional explosions in Nepal during 2008-2011 and to describe time trends and epidemiologic patterns for these events. Methods We analyzed surveillance data on fatal and non-fatal injuries due to intentional explosions in Nepal that occurred between 1 January 2008 and 31 December 2011. The case definition included casualties injured or killed by explosive devices knowingly activated by an individual or a group of individuals with the intent to harm, hurt or terrorize. Data were collected through media-based and active community-based surveillance. Results Analysis included 437 casualties injured or killed in 131 intentional explosion incidents. A decrease in the number of incidents and casualties between January 2008 and June 2009 was followed by a pronounced increase between July 2010 and June 2011. Eighty-four (19.2%) casualties were among females and 40 (9.2%) were among children under 18 years of age. Fifty-nine (45.3%) incidents involved one casualty, 47 (35.9%) involved 2 to 4 casualties, and 6 involved more than 10 casualties. The overall case-fatality ratio was 7.8%. The highest numbers of incidents occurred in streets or at crossroads, in victims’ homes, and in shops or markets. Incidents on buses and near stadiums claimed the highest numbers of casualties per incident. Socket, sutali, and pressure cooker bombs caused the highest numbers of incidents. Conclusions Intentional explosion incidents still pose a threat to the civilian population of Nepal. Most incidents are caused by small homemade explosive devices and occur in public places, and males aged 20 to 39 account for a plurality of casualties. Stakeholders addressing the explosive device problem in Nepal should continue to use surveillance data to plan interventions. PMID:23514664

Thermal imaging and analysis of short-lived Vulcanian explosions at Volcán de Colima, Mexico

NASA Astrophysics Data System (ADS)

Webb, Erica B.; Varley, Nick R.; Pyle, David M.; Mather, Tamsin A.

2014-05-01

Vulcanian explosions present a major hazard at many active volcanoes, but they also provide useful insights into the underlying behaviour of the volcanic system and therefore require close monitoring. Thermal infrared cameras are an effective tool for imaging Vulcanian explosion plumes since they capture detailed temperature information, and can reveal the internal dynamics of the plume-forming explosions. High spatial resolution thermal images of 200 small to moderate sized Vulcanian explosions from the summit crater of Volcán de Colima, Mexico, recorded between 2006 and 2011, were analysed to distinguish different event types and develop an explosion classification scheme. Explosions display a broad spectrum of sizes and characteristics, ranging between two typical end-members: “large-impulsive” events producing rapidly ascending explosion plumes up to heights of 600-1600 m above the crater rim, and “small-diffusive” events with plumes restricted to heights < 600 m. Most explosion plumes comprise a steady “gas-thrust” feeder plume below a convecting plume front. Others, that lack sufficient kinetic energy, rise buoyantly throughout the explosion, with steady buoyant ascent velocities ranging from ~ 1 m s- 1 to ~ 29 m s- 1. A time-series of thermal imagery throughout the period 2006-2011 reveals a weak relationship between apparent plume temperatures and lava dome extrusion, with the highest explosion temperatures coinciding with the onset of dome growth in early 2007. Temporal variations in the source locations of explosions across the summit crater are also identified and appear to show a close relationship to the patterns of lava dome growth and thermal evolution, with explosion source locations associated with the highest temperature thermal features.

DOE explosives safety manual

NASA Astrophysics Data System (ADS)

1990-05-01

The Department of Energy (DOE) policy requires that all activities be conducted in a manner that protects the safety of the public and provides a safe and healthful workplace for employees. DOE has also prescribed that all personnel be protected in any explosives operation undertaken. The level of safety provided shall be at least equivalent to that of the best industrial practice. The risk of death or serious injury shall be limited to the lowest practicable minimum. DOE and contractors shall continually review their explosives operations with the aim of achieving further refinements and improvements in safety practices and protective features. This manual describes the Department's explosive safety requirements applicable to operations involving the development, testing, handling, and processing of explosives or assemblies containing explosives. It is intended to reflect the state-of-the-art in explosives safety. In addition, it is essential that applicable criteria and requirements for implementing this policy be readily available and known to those responsible for conducting DOE programs. This document shall be periodically reviewed and updated to establish new requirements as appropriate. Users are requested to submit suggestions for improving the DOE Explosives Safety Manual through their appropriate Operations Office to the Office of Quality Programs.

Insights into different Strombolian explosive styles by remote controlled OP-FTIR (CERBERUS) measurements

NASA Astrophysics Data System (ADS)

Spina Alessandro, La; Mike, Burton; Filippo, Murè; Roberto, Maugeri

2014-05-01

In this paper we present the results and interpretation of gas composition data collected by a permanent OP-FTIR system (CERBERUS) installed at Stromboli summit. The instrument allows remote control observation and measurement of gas emissions from different points within volcano's crater terrace, using an integrated infrared camera / scanning mirror / FTIR system. Given that an OpenPath Fourier Transform InfraRed (FTIR) spectrometer allows the simultaneously measure all the major species contained in volcanic gas emissions, we could observe the different explosive styles fed by Stromboli volcano. Stromboli volcano, in the Aeolian island arc, is known as the "Lighthouse of the Mediterranean" for its regular (~every 10-20 min) explosive activity, launching crystal-rich black scoriae to 100-200 m height constituting a rich and impressive spectacle for both volcanologists and tourists from every part of the world. This ordinary activity has been classified in two types in relation to the their content of ash ejected. Type 1 is dominated melt ballistic particles whereas Type 2 consists of an ash-rich plume. On 18 July we recorded both explosive styles at the SW crater of Stromboli finding quite similar CO2/SO2 ratio, although we observed a higher value of SO2/HCl molar ratio for the Type 2. Moreover prior to both types of explosions the CO2 amount showed similar trend, whereas a different pattern in SO2 and in HCl gas content, was observed. In detail type 2 was preceded by decrease in SO2 and HCl amounts with respect to type 1. The decreasing trend observed before the onset of style 2 and the higher SO2/HCl ratio might be an indication of overpressure that might have induced the difference between the two types of explosions. In this context, the evidence of no change in the amount of CO2 and in CO2/SO2 ratio suggested us that this overpressure occurred in very shallow depths within the volcano feeding system. If our observations will be confirmed by other explosive event data, we will be able featuring the different source conditions triggering the ordinary explosive activity at Stromboli.

The extimated presence of differentiated higly explosive magmas beneath Vesuvius and Campi Flegrei: evidence from geochemical and textural studies.

NASA Astrophysics Data System (ADS)

Pappalardo, Lucia; Mastrolorenzo, Giuseppe

2010-05-01

Highly catastrophic explosive eruptions are supplied by Si-rich magmas, generated at shallower level in crust by the evolution of mantle liquids. The timescale of these evolution processes is a crucial factor, because of its control on the length of volcano repose interval leading to high explosive events. Campi Flegrei and Somma-Vesuvius alkaline volcanic systems, located respectively at few kilometers west and east of Neapolitan metropolitan area, produced a variety of eruptions ranging from not explosive lava flows and domes to highly destructive eruptions. Both these high risk volcanoes are in repose time since the last eruption occurred in the 1538 and 1944 BP, respectively. Since that time, the volcanoes experienced fumarolic activity, low level of seismicity with rare earthquakes swarms, as well as two bradyseismic crisis (1969-1972 and 1982-1984) localized in the center of Campi Flegrei caldera, that generated a net uplift of 3.5 m around the town of Pozzuoli. A wide low velocity layer interpreted as an extended magmatic body has been detected at 8-10 km depth beneath these volcanoes by seismic data. The capability of this reservoir to erupt explosively again strongly depends on magma differentiation degree, therefore the knowledge of the time lapse necessary at not explosive mafic liquids to differentiate toward explosive magmas is very crucial to predict the size of a possible short-term future eruption in Campanian area. Our petrologic data indicate that a multi-depth supply system was active under the Campanian Plain since 39 ka. Fractional crystallization during magma cooling associated with upward migration of less dense evolved liquids appears to be the prevalent differentiation process. Our results indicate that huge steam exolution occurred during the late stage of trachyte and phonolite crystallization thus accounting for the high Volcanic Explosivity Index (VEI) of eruptions supplied by these melts. Moreover our CSD data on phenocrysts reveal rapid crystallization and differentiation time for alkaline Campanian magmas (in the order of decades to few centuries). This evidence implies that the 400 km2 partial melting zone detected by tomography study at 8-10 km depth beneath Vesuvius and Campi Flegrei, should consist of differentiated magma already capable to produce also large scale (plinian) explosive events in case of renewal of the activity from the present closed-conduit state.

Remediation by in-situ solidification/stabilisation of Ardeer landfill, Scotland

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wyllie, M.; Esnault, A.; Barker, P.

1997-12-31

The Ardeer Landfill site at ICI Explosives factory on the west coast of Scotland had been a repository for waste from the site for 40 years. In order to safeguard the local environment ICI Explosives, with approval of Local Authorities and the Clyde River Purification Board put into action a programme of investigation and planning which culminated in the in-situ treatment of 10,000 m3 of waste within the landfill by a deep mixing method using the {open_quotes}Colmix{close_quotes} system. The paper describes in varying degrees of detail the remediation from investigation to the execution of the in-situ stabilisation and presents themore » post construction monitoring results.« less

A Binary Eutectic Mixture of TNAZ and R-Salt Explosives

NASA Astrophysics Data System (ADS)

Sandstrom, Mary; Manner, Virginia; Pemberton, Steven; Lloyd, Joseph; Tappan, Bryce

2011-06-01

TNAZ is a high performing explosive that is melt castable. However, the casting process can be problematic since TNAZ has a high vapor pressure exacerbated by a fairly high melting temperature. In order to mitigate the ill effects of its high vapor pressure, including a lower melting explosive was explored by making a series of mixtures of TNAZ and R-Salt. Initially, a eutectic temperature and composition was theoretically determined. Then a phase diagram was constructed from a series and mixtures by differential scanning calorimetery (DSC). The vapor pressure of the eutectic composition was determined by thermogravimetric analysis (TGA). Cylinder testing of the eutectic composition was carried out in copper tubes, 5'' long with 1/2 ``inner diameter and 1/16'' thick walls. The detonation velocity was measured using wire switches along the cylinder length and the expanding wall velocity was measured using PDV gauges. A rough evaluation of JWL equation-of-state parameters has been carried out. A more detailed evaluation is in progress.

What factors control the superficial lava dome explosivity?

NASA Astrophysics Data System (ADS)

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

2015-04-01

Dome-forming eruption is a frequent eruptive style; lava domes result from intermittent, slow extrusion of viscous lava. Most dome-forming eruptions produce highly microcrystallized and highly- to almost totally-degassed magmas which have a low explosive potential. During lava dome growth, recurrent collapses of unstable parts are the main destructive process of the lava dome, generating concentrated pyroclastic density currents (C-PDC) channelized in valleys. These C-PDC have a high, but localized, damage potential that largely depends on the collapsed volume. Sometimes, a dilute ash cloud surge develops at the top of the concentrated flow with an increased destructive effect because it may overflow ridges and affect larger areas. In some cases, large lava dome collapses can induce a depressurization of the magma within the conduit, leading to vulcanian explosions. By contrast, violent, laterally directed, explosions may occur at the base of a growing lava dome: this activity generates dilute and turbulent, highly-destructive, pyroclastic density currents (D-PDC), with a high velocity and propagation poorly dependent on the topography. Numerous studies on lava dome behaviors exist, but the triggering of lava dome explosions is poorly understood. Here, seven dome-forming eruptions are investigated: in the Lesser Antilles arc: Montagne Pelée, Martinique (1902-1905, 1929-1932 and 650 y. BP eruptions), Soufrière Hills, Montserrat; in Guatemala, Santiaguito (1929 eruption); in La Chaîne des Puys, France (Puy de Dome and Puy Chopine eruptions). We propose a new model of superficial lava-dome explosivity based upon a textural and geochemical study (vesicularity, microcrystallinity, cristobalite distribution, residual water contents, crystal transit times) of clasts produced by these key eruptions. Superficial explosion of a growing lava dome may be promoted through porosity reduction caused by both vesicle flattening due to gas escape and syn-eruptive cristobalite precipitation. Both processes generate an impermeable and rigid carapace allowing overpressurisation of the inner parts of the lava dome by the rapid input of vesiculated magma batches. The thickness of the cristobalite-rich carapace is an inverse function of the external lava dome surface area. Thus the probability of a superficial lava dome explosion inversely depends on its size; explosive activity more likely occurs at the onset of the lava dome extrusion in agreement with observations. We evidence a two-step process in magma ascent with edification of the lava dome that may be accompanied by a rapid ascent of an undegassed batch of magma some days prior the explosive activity. This new result is of interest for the whole volcanological community and for risk management.

Explosives Removal from Munitions Wastewaters

DTIC Science & Technology

1975-01-01

activated carbon columns. Waste water, for the study was drawn as needed from the effluent of the i diatomaceous earth filters and stored in an 800-gallon...explosive Laterials, such as DNT and nitrocresols, from waste streams. The loaded adsorbent can be regenerated with solvent. To minimize operating costs...most effective is fixed-bed adsorption followir.nI clarification and filtration to remove suspended j solids. Activated carbon adsorbent is used at a

Littoral hydrovolcanic explosions: A case study of lava-seawater interaction at Kilauea Volcano

USGS Publications Warehouse

Mattox, T.N.; Mangan, M.T.

1997-01-01

A variety of hydrovolcanic explosions may occur as basaltic lava flows into the ocean. Observations and measurements were made during a two-year span of unusually explosive littoral activity as tube-fed pahoehoe from Kilauea Volcano inundated the southeast coastline of the island of Hawai'i. Our observations suggest that explosive interactions require high entrance fluxes (??? 4 m3/s) and are most often initiated by collapse of a developing lava delta. Two types of interactions were observed. "Open mixing" of lava and seawater occurred when delta collapse exposed the mouth of a severed lava tube or incandescent fault scarp to wave action. The ensuing explosions produced unconsolidated deposits of glassy lava fragments or lithic debris. Interactions under "confined mixing" conditions occurred when a lava tube situated at or below sea level fractured. Explosions ruptured the roof of the tube and produced circular mounds of welded spatter. We estimate a water/rock mass ratio of 0.15 for the most common type of littoral explosion and a kinetic energy release of 0.07-1.3 kJ/kg for the range of events witnessed.

Time-sequenced X-ray Observation of a Thermal Explosion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tringe, J W; Molitoris, J D; Smilowitz, L

The evolution of a thermally-initiated explosion is studied using a multiple-image x-ray system. HMX-based PBX 9501 is used in this work, enabling direct comparison to recently-published data obtained with proton radiography [1]. Multiple x-ray images of the explosion are obtained with image spacing of ten microseconds or more. The explosion is simultaneously characterized with a high-speed camera using an interframe spacing of 11 {micro}s. X-ray and camera images were both initiated passively by signals from an embedded thermocouple array, as opposed to being actively triggered by a laser pulse or other external source. X-ray images show an accelerating reacting frontmore » within the explosive, and also show unreacted explosive at the time the containment vessel bursts. High-speed camera images show debris ejected from the vessel expanding at 800-2100 m/s in the first tens of {micro}s after the container wall failure. The effective center of the initiation volume is about 6 mm from the geometric center of the explosive.« less

TerraSAR-X interferometry reveals small-scale deformation associated with the summit eruption of Kīlauea Volcano, Hawai`i

NASA Astrophysics Data System (ADS)

Richter, Nicole; Poland, Michael P.; Lundgren, Paul R.

2013-04-01

On 19 March 2008, a small explosive eruption at the summit of Kīlauea Volcano, Hawai`i, heralded the formation of a new vent along the east wall of Halema`uma`u Crater. In the ensuing years, the vent widened due to collapses of the unstable rim and conduit wall; some collapses impacted an actively circulating lava pond and resulted in small explosive events. We used synthetic aperture radar data collected by the TerraSAR-X satellite, a joint venture between the German Aerospace Center (DLR) and EADS Astrium, to identify and analyze small-scale surface deformation around the new vent during 2008-2012. Lidar data were used to construct a digital elevation model to correct for topographic phase, allowing us to generate differential interferograms with a spatial resolution of about 3 m in Kīlauea's summit area. These interferograms reveal subsidence within about 100 m of the rim of the vent. Small baseline subset time series analysis suggests that the subsidence rate is not constant and, over time, may provide an indication of vent stability and potential for rim and wall collapse—information with obvious hazard implications. The deformation is not currently detectable by other space- or ground-based techniques.

TerraSAR-X interferometry reveals small-scale deformation associated with the summit eruption of Kilauea Volcano, Hawai‘i

USGS Publications Warehouse

Richter, Nichole; Poland, Michael P.; Lundgren, Paul R.

2013-01-01

On 19 March 2008, a small explosive eruption at the summit of Kīlauea Volcano, Hawai‘i, heralded the formation of a new vent along the east wall of Halema‘uma‘u Crater. In the ensuing years, the vent widened due to collapses of the unstable rim and conduit wall; some collapses impacted an actively circulating lava pond and resulted in small explosive events. We used synthetic aperture radar data collected by the TerraSAR-X satellite, a joint venture between the German Aerospace Center (DLR) and EADS Astrium, to identify and analyze small-scale surface deformation around the new vent during 2008-2012. Lidar data were used to construct a digital elevation model to correct for topographic phase, allowing us to generate differential interferograms with a spatial resolution of about 3 m in Kīlauea's summit area. These interferograms reveal subsidence within about 100 m of the rim of the vent. Small baseline subset time series analysis suggests that the subsidence rate is not constant and, over time, may provide an indication of vent stability and potential for rim and wall collapse -- information with obvious hazard implications. The deformation is not currently detectable by other space- or ground-based techniques.

Preliminary report on the Black Thunder, Wyoming CTBT R and D experiment quicklook report: LLNL input from regional stations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harben, P.E.; Glenn, L.A.

This report presents a preliminary summary of the data recorded at three regional seismic stations from surface blasting at the Black Thunder Coal Mine in northeast Wyoming. The regional stations are part of a larger effort that includes many more seismic stations in the immediate vicinity of the mine. The overall purpose of this effort is to characterize the source function and propagation characteristics of large typical surface mine blasts. A detailed study of source and propagation features of conventional surface blasts is a prerequisite to attempts at discriminating this type of blasting activity from other sources of seismic events.more » The Black Thunder Seismic experiment is a joint verification effort to determine seismic source and path effects that result from very large, but routine ripple-fired surface mining blasts. Studies of the data collected will be for the purpose of understanding how the near-field and regional seismic waveforms from these surface mining blasts are similar to, and different from, point shot explosions and explosions at greater depth. The Black Hills Station is a Designated Seismic Station that was constructed for temporary occupancy by the Former Soviet Union seismic verification scientists in accordance with the Threshold Test Ban Treaty protocol.« less

3-D Velocimetry of Strombolian Explosions

NASA Astrophysics Data System (ADS)

Taddeucci, J.; Gaudin, D.; Orr, T. R.; Scarlato, P.; Houghton, B. F.; Del Bello, E.

2014-12-01

Using two synchronized high-speed cameras we were able to reconstruct the three-dimensional displacement and velocity field of bomb-sized pyroclasts in Strombolian explosions at Stromboli Volcano. Relatively low-intensity Strombolian-style activity offers a rare opportunity to observe volcanic processes that remain hidden from view during more violent explosive activity. Such processes include the ejection and emplacement of bomb-sized clasts along pure or drag-modified ballistic trajectories, in-flight bomb collision, and gas liberation dynamics. High-speed imaging of Strombolian activity has already opened new windows for the study of the abovementioned processes, but to date has only utilized two-dimensional analysis with limited motion detection and ability to record motion towards or away from the observer. To overcome this limitation, we deployed two synchronized high-speed video cameras at Stromboli. The two cameras, located sixty meters apart, filmed Strombolian explosions at 500 and 1000 frames per second and with different resolutions. Frames from the two cameras were pre-processed and combined into a single video showing frames alternating from one to the other camera. Bomb-sized pyroclasts were then manually identified and tracked in the combined video, together with fixed reference points located as close as possible to the vent. The results from manual tracking were fed to a custom software routine that, knowing the relative position of the vent and cameras, and the field of view of the latter, provided the position of each bomb relative to the reference points. By tracking tens of bombs over five to ten frames at different intervals during one explosion, we were able to reconstruct the three-dimensional evolution of the displacement and velocity fields of bomb-sized pyroclasts during individual Strombolian explosions. Shifting jet directivity and dispersal angle clearly appear from the three-dimensional analysis.

Fundamental changes in the activity of the natrocarbonatite volcano Oldoinyo Lengai, Tanzania

USGS Publications Warehouse

Kervyn, M.; Ernst, G.G.J.; Keller, J.; Vaughan, R. Greg; Klaudius, J.; Pradal, E.; Belton, F.; Mattsson, H.B.; Mbede, E.; Jacobs, P.M.

2010-01-01

On September 4, 2007, after 25 years of effusive natrocarbonatite eruptions, the eruptive activity of Oldoinyo Lengai (OL), N Tanzania, changed abruptly to episodic explosive eruptions. This transition was preceded by a voluminous lava eruption in March 2006, a year of quiescence, resumption of natrocarbonatite eruptions in June 2007, and a volcano-tectonic earthquake swarm in July 2007. Despite the lack of ground-based monitoring, the evolution in OL eruption dynamics is documented based on the available field observations, ASTER and MODIS satellite images, and almost-daily photos provided by local pilots. Satellite data enabled identification of a phase of voluminous lava effusion in the 2 weeks prior to the onset of explosive eruptions. After the onset, the activity varied from 100 m high ash jets to 2–15 km high violent, steady or unsteady, eruption columns dispersing ash to 100 km distance. The explosive eruptions built up a ∼400 m wide, ∼75 m high intra-crater pyroclastic cone. Time series data for eruption column height show distinct peaks at the end of September 2007 and February 2008, the latter being associated with the first pyroclastic flows to be documented at OL. Chemical analyses of the erupted products, presented in a companion paper (Keller et al.2010), show that the 2007–2008 explosive eruptions are associated with an undersaturated carbonated silicate melt. This new phase of explosive eruptions provides constraints on the factors causing the transition from natrocarbonatite effusive eruptions to explosive eruptions of carbonated nephelinite magma, observed repetitively in the last 100 years at OL.

Hydroacoustic, infrasonic and seismic monitoring of the submarine eruptive activity and sub-aerial plume generation at South Sarigan, May 2010

NASA Astrophysics Data System (ADS)

Green, David N.; Evers, Läslo G.; Fee, David; Matoza, Robin S.; Snellen, Mirjam; Smets, Pieter; Simons, Dick

2013-05-01

Explosive submarine volcanic processes are poorly understood, due to the difficulties associated with both direct observation and continuous monitoring. In this study hydroacoustic, infrasound, and seismic signals recorded during the May 2010 submarine eruption of South Sarigan seamount, Marianas Arc, are used to construct a detailed event chronology. The signals were recorded on stations of the International Monitoring System, which is a component of the verification measures for the Comprehensive Nuclear-Test-Ban Treaty. Numerical hydroacoustic and infrasound propagation modelling confirms that viable propagation paths from the source to receivers exist, and provide traveltimes allowing signals recorded on the different technologies to be associated. The eruption occurred in three stages, separated by three-hour periods of quiescence. 1) A 46 h period during which broadband impulsive hydroacoustic signals were generated in clusters lasting between 2 and 13 min. 95% of the 7602 identified events could be classified into 4 groups based on their waveform similarity. The time interval between clusters decreased steadily from 80 to 25 min during this period. 2) A five-hour period of 10 Hz hydroacoustic tremor, interspersed with large-amplitude, broadband signals. Associated infrasound signals were also recorded at this time. 3) An hour-long period of transient broadband events culminated in two large-amplitude hydroacoustic events and one broadband infrasound signal. A speculative interpretation, consistent with the data, suggests that during phase (1) transitions between endogenous dome growth and phreatomagmatic explosions occurred with the magma ascent rate accelerating throughout the period; during phase (2) continuous venting of fragmented magma occurred, and was powerful enough to breach the sea surface. During the climactic phase (3) discrete powerful explosions occurred, and sufficient seawater was vaporised to produce the contemporaneous 12 km altitude steam plume.

Observations of eruption clouds from Sakura-zima volcano, Kyushu, Japan from Skylab 4

USGS Publications Warehouse

Friedman, J.D.; Heiken, G.; Randerson, D.; McKay, D.S.

1976-01-01

Hasselblad and Nikon stereographic photographs taken from Skylab between 9 June 1973 and 1 February 1974 give synoptic plan views of several entire eruption clouds emanating from Sakura-zima volcano in Kagoshima Bay, Kyushu, Japan. Analytical plots of these stereographic pairs, studied in combination with meteorological data, indicate that the eruption clouds did not penetrate the tropopause and thus did not create a stratospheric dust veil of long residence time. A horizontal eddy diffusivity of the order of 106 cm2 s-1 and a vertical eddy diffusivity of the order of 105 cm2 s-1 were calculated from the observed plume dimensions and from available meteorological data. These observations are the first, direct evidence that explosive eruption at an estimated energy level of about 1018 ergs per paroxysm may be too small under atmospheric conditions similar to those prevailing over Sakura-zima for volcanic effluents to penetrate low-level tropospheric temperature inversions and, consequently, the tropopause over northern middle latitudes. Maximum elevation of the volcanic clouds was determined to be 3.4 km. The cumulative thermal energy release in the rise of volcanic plumes for 385 observed explosive eruptions was estimated to be 1020 to 1021 ergs (1013 to 1014 J), but the entire thermal energy release associated with pyroclastic activity may be of the order of 2.5 ?? 1022 ergs (2.5 ?? 1015 J). Estimation of the kinetic energy component of explosive eruptions via satellite observation and meteorological consideration of eruption clouds is thus useful in volcanology as an alternative technique to confirm the kinetic energy estimates made by ground-based geological and geophysical methods, and to aid in construction of physical models of potential and historical tephra-fallout sectors with implications for volcano-hazard prediction. ?? 1976.

From Vulcanian explosions to sustained explosive eruptions: The role of diffusive mass transfer in conduit flow dynamics

NASA Astrophysics Data System (ADS)

Mason, R. M.; Starostin, A. B.; Melnik, O. E.; Sparks, R. S. J.

2006-05-01

Magmatic explosive eruptions are influenced by mass transfer processes of gas diffusion into bubbles caused by decompression. Melnik and Sparks [Melnik, O.E., Sparks, R.S.J. 2002, Modelling of conduit flow dynamic during explosive activity at Soufriere Hills Volcano, Montserrat. In: Druitt, T.H., Kokelaar, B.P. (eds). The Eruption of Soufriere Hills Volcano, Montserrat, from 1995 to 1999. Geological Society, London, Memoirs, 21, 307-317] proposed two end member cases corresponding to complete equilibrium and complete disequilibrium. In the first case, diffusion is fast enough to maintain the system near equilibrium and a long-lived explosive eruption develops. In the latter case, pre-existing bubbles expand under conditions of explosive eruption and decompression, but diffusive gas transfer is negligible. This leads to a much shorter eruption. Here we develop this model to consider the role of mass transfer by investigating transient flows at the start of an explosive eruption triggered by a sudden decompression. The simulations reveal a spectrum of behaviours from sustained to short-lived highly non-equilibrium Vulcanian-style explosions lasting a few tens of seconds, through longer lasting eruptions that can be sustained for tens of minutes and finally to eruptions that can last hours or even days. Behaviour is controlled by a mass-transfer parameter, ω, which equals n*2/3D, where n* is the bubble number density and D is the diffusivity. The parameter ω is expected to vary between 10 - 5 and 1 s - 1 in nature and reflects a time-scale for efficient diffusion. The spectrum of model behaviours is consistent with variations in styles of explosive eruptions of silicic volcanoes. In the initial stages peak discharges occur over 10-20 s and then decline to low discharges. If a critical bubble overpressure is assumed to be the criterion for fragmentation then fragmentation may stop and start several times in the declining period causing several pulses of high-intensity discharge. For the cases of strong disequilibria, the fluxes can decrease to negligible values where other processes, such as gas escape through permeable magma, prevents explosive conditions becoming re-established so that explosive activity stops and dome growth can start. For cases closer to the equilibrium the eruption can evolve towards a quasi-steady sustained flow, never declining sufficiently for gas escape to become dominant.

Acoustic wavefield and Mach wave radiation of flashing arcs in strombolian explosion measured by image luminance

NASA Astrophysics Data System (ADS)

Genco, Riccardo; Ripepe, Maurizio; Marchetti, Emanuele; Bonadonna, Costanza; Biass, Sebastien

2014-10-01

Explosive activity often generates visible flashing arcs in the volcanic plume considered as the evidence of the shock-front propagation induced by supersonic dynamics. High-speed image processing is used to visualize the pressure wavefield associated with flashing arcs observed in strombolian explosions. Image luminance is converted in virtual acoustic signal compatible with the signal recorded by pressure transducer. Luminance variations are moving with a spherical front at a 344.7 m/s velocity. Flashing arcs travel at the sound speed already 14 m above the vent and are not necessarily the evidence of a supersonic explosive dynamics. However, seconds later, the velocity of small fragments increases, and the spherical acousto-luminance wavefront becomes planar recalling the Mach wave radiation generated by large scale turbulence in high-speed jet. This planar wavefront forms a Mach angle of 55° with the explosive jet axis, suggesting an explosive dynamics moving at Mo = 1.22 Mach number.

Fluorescence based explosive detection: from mechanisms to sensory materials.

PubMed

Sun, Xiangcheng; Wang, Ying; Lei, Yu

2015-11-21

The detection of explosives is one of the current pressing concerns in global security. In the past few decades, a large number of emissive sensing materials have been developed for the detection of explosives in vapor, solution, and solid states through fluorescence methods. In recent years, great efforts have been devoted to develop new fluorescent materials with various sensing mechanisms for detecting explosives in order to achieve super-sensitivity, ultra-selectivity, as well as fast response time. This review article starts with a brief introduction on various sensing mechanisms for fluorescence based explosive detection, and then summarizes in an exhaustive and systematic way the state-of-the-art of fluorescent materials for explosive detection with a focus on the research in the recent 5 years. A wide range of fluorescent materials, such as conjugated polymers, small fluorophores, supramolecular systems, bio-inspired materials and aggregation induced emission-active materials, and their sensing performance and sensing mechanism are the centerpiece of this review. Finally, conclusions and future outlook are presented and discussed.

Understanding the shock and detonation response of high explosives at the continuum and meso scales

NASA Astrophysics Data System (ADS)

Handley, C. A.; Lambourn, B. D.; Whitworth, N. J.; James, H. R.; Belfield, W. J.

2018-03-01

The shock and detonation response of high explosives has been an active research topic for more than a century. In recent years, high quality data from experiments using embedded gauges and other diagnostic techniques have inspired the development of a range of new high-fidelity computer models for explosives. The experiments and models have led to new insights, both at the continuum scale applicable to most shock and detonation experiments, and at the mesoscale relevant to hotspots and burning within explosive microstructures. This article reviews the continuum and mesoscale models, and their application to explosive phenomena, gaining insights to aid future model development and improved understanding of the physics of shock initiation and detonation propagation. In particular, it is argued that "desensitization" and the effect of porosity on high explosives can both be explained by the combined effect of thermodynamics and hydrodynamics, rather than the traditional hotspot-based explanations linked to pressure-dependent reaction rates.

High explosive spot test analyses of samples from Operable Unit (OU) 1111

DOE Office of Scientific and Technical Information (OSTI.GOV)

McRae, D.; Haywood, W.; Powell, J.

1995-01-01

A preliminary evaluation has been completed of environmental contaminants at selected sites within the Group DX-10 (formally Group M-7) area. Soil samples taken from specific locations at this detonator facility were analyzed for harmful metals and screened for explosives. A sanitary outflow, a burn pit, a pentaerythritol tetranitrate (PETN) production outflow field, an active firing chamber, an inactive firing chamber, and a leach field were sampled. Energy dispersive x-ray fluorescence (EDXRF) was used to obtain semi-quantitative concentrations of metals in the soil. Two field spot-test kits for explosives were used to assess the presence of energetic materials in the soilmore » and in items found at the areas tested. PETN is the major explosive in detonators manufactured and destroyed at Los Alamos. No measurable amounts of PETN or other explosives were detected in the soil, but items taken from the burn area and a high-energy explosive (HE)/chemical sump were contaminated. The concentrations of lead, mercury, and uranium are given.« less

49 CFR 174.110 - Car magazine.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 2 2012-10-01 2012-10-01 false Car magazine. 174.110 Section 174.110...) Materials § 174.110 Car magazine. When specially authorized by the carrier, Division 1.1 or 1.2 (explosive) materials in quantity not exceeding 68 kg (150 pounds) may be carried in construction or repair cars if the...

49 CFR 174.110 - Car magazine.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 2 2013-10-01 2013-10-01 false Car magazine. 174.110 Section 174.110...) Materials § 174.110 Car magazine. When specially authorized by the carrier, Division 1.1 or 1.2 (explosive) materials in quantity not exceeding 68 kg (150 pounds) may be carried in construction or repair cars if the...

49 CFR 174.110 - Car magazine.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Car magazine. 174.110 Section 174.110...) Materials § 174.110 Car magazine. When specially authorized by the carrier, Division 1.1 or 1.2 (explosive) materials in quantity not exceeding 68 kg (150 pounds) may be carried in construction or repair cars if the...

49 CFR 174.110 - Car magazine.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 2 2011-10-01 2011-10-01 false Car magazine. 174.110 Section 174.110...) Materials § 174.110 Car magazine. When specially authorized by the carrier, Division 1.1 or 1.2 (explosive) materials in quantity not exceeding 68 kg (150 pounds) may be carried in construction or repair cars if the...

49 CFR 174.110 - Car magazine.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 2 2014-10-01 2014-10-01 false Car magazine. 174.110 Section 174.110...) Materials § 174.110 Car magazine. When specially authorized by the carrier, Division 1.1 or 1.2 (explosive) materials in quantity not exceeding 68 kg (150 pounds) may be carried in construction or repair cars if the...

27 CFR 555.103 - Transactions among licensees/permittees and transactions among licensees and holders of user...

Code of Federal Regulations, 2010 CFR

2010-04-01

... organization showing the name, address, and date and place of birth of each representative or agent. A licensee... explosive materials, e.g., resale, mining, quarrying, agriculture, construction, sport rocketry, road... certified statement of intended use must specify the name, address, date and place of birth, and social...

33 CFR 159.95 - Safety.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Safety. 159.95 Section 159.95... SANITATION DEVICES Design, Construction, and Testing § 159.95 Safety. (a) Each device must— (1) Be free of... explosion or over pressurization as a result of an accumulation of gases; and (3) Meet all other safety...

Lightning and electrical activity during the Shiveluch volcano eruption on 16 November 2014

NASA Astrophysics Data System (ADS)

Shevtsov, Boris M.; Firstov, Pavel P.; Cherneva, Nina V.; Holzworth, Robert H.; Akbashev, Renat R.

2016-03-01

According to World Wide Lightning Location Network (WWLLN) data, a sequence of lightning discharges was detected which occurred in the area of the explosive eruption of Shiveluch volcano on 16 November 2014 in Kamchatka. Information on the ash cloud motion was confirmed by the measurements of atmospheric electricity, satellite observations and meteorological and seismic data. It was concluded that WWLLN resolution is enough to detect the earlier stage of volcanic explosive eruption when electrification processes develop the most intensively. The lightning method has the undeniable advantage for the fast remote sensing of volcanic electric activity anywhere in the world. There is a good opportunity for the development of WWLLN technology to observe explosive volcanic eruptions.

Magnetic Reconfiguration in Explosive Solar Activity

NASA Technical Reports Server (NTRS)

Antiochos, Spiro K.

2008-01-01

A fundamental property of the Sun's corona i s that it is violently dynamic. The most spectacular and most energetic manifestations of this activity are the giant disruptions that give rise to coronal mass ejections (CME) and eruptive flares. These major events are of critical importance, because they drive the most destructive forms of space weather at Earth and in the solar system, and they provide a unique opportunity to study, in revealing detail, the interaction of magnetic field and matter, in particular, magnetohydrodynamic instability and nonequilibrium -- processes that are at the heart of laboratory and astrophysical plasma physics. Recent observations by a number of NASA space missions have given us new insights into the physical mechanisms that underlie coronal explosions. Furthermore, massively-parallel computation have now allowed us to calculate fully three-dimensional models for solar activity. In this talk I will present some of the latest observations of the Sun, including those from the just-launched Hinode and STEREO mission, and discuss recent advances in the theory and modeling of explosive solar activity.

Radioactivity in trinitite six decades later.

PubMed

Parekh, Pravin P; Semkow, Thomas M; Torres, Miguel A; Haines, Douglas K; Cooper, Joseph M; Rosenberg, Peter M; Kitto, Michael E

2006-01-01

The first nuclear explosion test, named the Trinity test, was conducted on July 16, 1945 near Alamogordo, New Mexico. In the tremendous heat of the explosion, the radioactive debris fused with the local soil into a glassy material named Trinitite. Selected Trinitite samples from ground zero (GZ) of the test site were investigated in detail for radioactivity. The techniques used included alpha spectrometry, high-efficiency gamma-ray spectrometry, and low-background beta counting, following the radiochemistry for selected radionuclides. Specific activities were determined for fission products (90Sr, 137Cs), activation products (60Co, 133Ba, 152Eu, 154Eu, 238Pu, 241Pu), and the remnants of the nuclear fuel (239Pu, 240Pu). Additionally, specific activities of three natural radionuclides (40K, 232Th, 238U) and their progeny were measured. The determined specific activities of radionuclides and their relationships are interpreted in the context of the fission process, chemical behavior of the elements, as well as the nuclear explosion phenomenology.

Isotopic signature of atmospheric xenon released from light water reactors.

PubMed

Kalinowski, Martin B; Pistner, Christoph

2006-01-01

A global monitoring system for atmospheric xenon radioactivity is being established as part of the International Monitoring System to verify compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The isotopic activity ratios of (135)Xe, (133m)Xe, (133)Xe and (131m)Xe are of interest for distinguishing nuclear explosion sources from civilian releases. Simulations of light water reactor (LWR) fuel burn-up through three operational reactor power cycles are conducted to explore the possible xenon isotopic signature of nuclear reactor releases under different operational conditions. It is studied how ratio changes are related to various parameters including the neutron flux, uranium enrichment and fuel burn-up. Further, the impact of diffusion and mixing on the isotopic activity ratio variability are explored. The simulations are validated with reported reactor emissions. In addition, activity ratios are calculated for xenon isotopes released from nuclear explosions and these are compared to the reactor ratios in order to determine whether the discrimination of explosion releases from reactor effluents is possible based on isotopic activity ratios.

Cubanes: Super explosives and potential pharmaceutical intermediates

NASA Technical Reports Server (NTRS)

Bashir-Hashemi, A.

1994-01-01

The cubane molecule, in which eight carbon atoms are locked in a cubic framework, shows great potential for both military and pharmaceutical applications. Octanitrocubane, with a predicted density of 2.1 g/cc and strain energy of more than 165 kcal/mol, is considered to be the 'super-explosive', while cubane derivatives submitted to the National Institutes of Health for preliminary biological activity screening have displayed promising anti-cancer and anti-HIV activity.

Blast waves from violent explosive activity at Yasur Volcano, Vanuatu

NASA Astrophysics Data System (ADS)

Marchetti, E.; Ripepe, M.; Delle Donne, D.; Genco, R.; Finizola, A.; Garaebiti, E.

2013-11-01

and seismic waveforms were collected during violent strombolian activity at Yasur Volcano (Vanuatu). Averaging ~3000 seismic events showed stable waveforms, evidencing a low-frequency (0.1-0.3 Hz) signal preceding ~5-6 s the explosion. Infrasonic waveforms were mostly asymmetric with a sharp compressive (5-106 Pa) onset, followed by a small long-lasting rarefaction phase. Regardless of the pressure amplitude, the ratio between the positive and negative phases was constant. These waveform characteristics closely resembled blast waves. Infrared imagery showed an apparent cold spherical front ~20 m thick, which moved between 342 and 405 m/s before the explosive hot gas/fragments cloud. We interpret this cold front as that produced by the vapor condensation induced by the passage of the shock front. We suggest that violent strombolian activity at Yasur was driven by supersonic dynamics with gas expanding at 1.1 Mach number inside the conduit.

A metric space for Type Ia supernova spectra: a new method to assess explosion scenarios

NASA Astrophysics Data System (ADS)

Sasdelli, Michele; Hillebrandt, W.; Kromer, M.; Ishida, E. E. O.; Röpke, F. K.; Sim, S. A.; Pakmor, R.; Seitenzahl, I. R.; Fink, M.

2017-04-01

Over the past years, Type Ia supernovae (SNe Ia) have become a major tool to determine the expansion history of the Universe, and considerable attention has been given to, both, observations and models of these events. However, until now, their progenitors are not known. The observed diversity of light curves and spectra seems to point at different progenitor channels and explosion mechanisms. Here, we present a new way to compare model predictions with observations in a systematic way. Our method is based on the construction of a metric space for SN Ia spectra by means of linear principal component analysis, taking care of missing and/or noisy data, and making use of partial least-squares regression to find correlations between spectral properties and photometric data. We investigate realizations of the three major classes of explosion models that are presently discussed: delayed-detonation Chandrasekhar-mass explosions, sub-Chandrasekhar-mass detonations and double-degenerate mergers, and compare them with data. We show that in the principal component space, all scenarios have observed counterparts, supporting the idea that different progenitors are likely. However, all classes of models face problems in reproducing the observed correlations between spectral properties and light curves and colours. Possible reasons are briefly discussed.

Gas chromatographic detection of some nitro explosive compounds in soil samples after solid-phase microextraction with carbon ceramic copper nanoparticle fibers.

PubMed

Farhadi, Khalil; Bochani, Shayesteh; Hatami, Mehdi; Molaei, Rahim; Pirkharrati, Hossein

2014-07-01

In this research, a new solid-phase microextraction fiber based on carbon ceramic composites with copper nanoparticles followed by gas chromatography with flame ionization detection was applied for the extraction and determination of some nitro explosive compounds in soil samples. The proposed method provides an overview of trends related to synthesis of solid-phase microextraction sorbents and their applications in preconcentration and determination of nitro explosives. The sorbents were prepared by mixing of copper nanoparticles with a ceramic composite produced by mixture of methyltrimethoxysilane, graphite, methanol, and hydrochloric acid. The prepared sorbents were coated on copper wires by dip-coating method. The prepared nanocomposites were evaluated statistically and provided better limits of detection than the pure carbon ceramic. The limit of detection of the proposed method was 0.6 μg/g with a linear response over the concentration range of 2-160 μg/g and square of correlation coefficient >0.992. The new proposed fiber has been demonstrated to be a suitable, inexpensive, and sensitive candidate for extraction of nitro explosive compounds in contaminated soil samples. The constructed fiber can be used more than 100 times without the need for surface generation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Aspects of the Application of Cavity Enhanced Spectroscopy to Nitrogen Oxides Detection

PubMed Central

Wojtas, Jacek; Mikolajczyk, Janusz; Bielecki, Zbigniew

2013-01-01

This article presents design issues of high-sensitive laser absorption spectroscopy systems for nitrogen oxides (NOx) detection. Examples of our systems and their investigation results are also described. The constructed systems use one of the most sensitive methods, cavity enhanced absorption spectroscopy (CEAS). They operate at different wavelength ranges using a blue—violet laser diode (410 nm) as well as quantum cascade lasers (5.27 μm and 4.53 μm). Each of them is configured as a one or two channel measurement device using, e.g., time division multiplexing and averaging. During the testing procedure, the main performance features such as detection limits and measurements uncertainties have been determined. The obtained results are 1 ppb NO2, 75 ppb NO and 45 ppb N2O. For all systems, the uncertainty of concentration measurements does not exceed a value of 13%. Some experiments with explosives are also discussed. A setup equipped with a concentrator of explosives vapours was used. The detection method is based either on the reaction of the sensors to the nitrogen oxides directly emitted by the explosives or on the reaction to the nitrogen oxides produced during thermal decomposition of explosive vapours. For TNT, PETN, RDX and HMX a detection limit better than 1 ng has been achieved. PMID:23752566

Relaxed structure of typical nitro explosives in the excited state: Observation, implication and application

NASA Astrophysics Data System (ADS)

Chu, Genbai; Yang, Zuhua; Xi, Tao; Xin, Jianting; Zhao, Yongqiang; He, Weihua; Shui, Min; Gu, Yuqiu; Xiong, Ying; Xu, Tao

2018-04-01

Understanding the structural, geometrical, and chemical changes that occur after an electronic excitation is essential to elucidate the inherent mechanism of nitro explosives. Herein, relaxed structures of typical nitro explosives in the lowest singlet excited state are investigated using time-dependent density functional theory. During the excitation process, the nitro group is activated and relaxes via geometrical change. The five explosives RDX, HMX, CL-20, PETN, and LLM-105 exhibit similar relaxed structures, and the impact sensitivity is related to their excitation energy. High-sensitivity δ-HMX has a lower excitation energy for relaxed structure than β-HMX. This study offers novel insight into energetic materials.

SO2 emissions at Semeru volcano, Indonesia: Characterization and quantification of persistent and periodic explosive activity

NASA Astrophysics Data System (ADS)

Smekens, Jean-François; Clarke, Amanda B.; Burton, Michael R.; Harijoko, Agung; Wibowo, Haryo E.

2015-07-01

We present the first measurements of SO2 emissions at Semeru volcano, Indonesia, using an SO2 camera. Activity at Semeru is characterized by quiescent degassing interspersed with short-lived explosive events with low ash burden. The interval between explosions was measured at 32.1 ± 15.7 min in a webcam survey of the volcano between the months of June and December 2013. We distinguish between two types of events: shorter events (type I: 5 min duration) with emissions returning quickly to baseline levels, and longer events (type II: 15 min duration) often showing multiple pulses and a longer period of increased emissions before a return to quiescent levels. Type I events represent > 90% of the activity and release an average of 200-500 kg of SO2 per event. The single type II event we documented with the SO2 camera released a total of 1460 kg of SO2. We estimate the daily average emissions of Semeru to be 21-71 t d- 1 of SO2, amounting to a yearly output of 8-26 Gg (8000-26,000 metric tons), with 35-65% released during explosive events. The time series patterns of degassing are consistent with the existence of a viscous plug at the top of the conduit, which seals the conduit immediately prior to explosive events, causing pressurization of the underlying magma followed by a sudden release of gas and fragmented magma.

Active sampling technique to enhance chemical signature of buried explosives

NASA Astrophysics Data System (ADS)

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.

77 FR 15393 - Agency Information Collection Activities: Proposed Collection; Comments Requested: Firearms...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-15

... Services Division Customer Service Survey ACTION: 30-Day notice of information collection. The Department.... (2) Title of the Form/Collection: Firearms & Explosives Services Division Customer Service Survey. (3... firearms and explosives industry. This anonymous survey would allow FESD to gauge customer satisfaction and...

50 CFR 218.30 - Specified activity and specified geographical area and effective dates.

Code of Federal Regulations, 2011 CFR

2011-10-01

...) Underwater Explosives: (A) MK-83 (1,000 lb High Explosive bomb); (B) MK3A2 anti-swimmer concussion grenades... Training with MK3A2 anti-swimmer concussion grenades—up to 30 events over the course of 5 years (an average...

Kamchatka and North Kurile Volcano Explosive Eruptions in 2015 and Danger to Aviation

NASA Astrophysics Data System (ADS)

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

2016-04-01

There are 36 active volcanoes in the Kamchatka and North Kurile, and several of them are continuously active. In 2015, four of the Kamchatkan volcanoes (Sheveluch, Klyuchevskoy, Karymsky and Zhupanovsky) and two volcanoes of North Kurile (Alaid and Chikurachki) had strong and moderate explosive eruptions. Moderate gas-steam activity was observing of Bezymianny, Kizimen, Avachinsky, Koryaksky, Gorely, Mutnovsky and other volcanoes. Strong explosive eruptions of volcanoes are the most dangerous for aircraft because they can produce in a few hours or days to the atmosphere and the stratosphere till several cubic kilometers of volcanic ash and aerosols. Ash plumes and the clouds, depending on the power of the eruption, the strength and wind speed, can travel thousands of kilometers from the volcano for several days, remaining hazardous to aircraft, as the melting temperature of small particles of ash below the operating temperature of jet engines. The eruptive activity of Sheveluch volcano began since 1980 (growth of the lava dome) and is continuing at present. Strong explosive events of the volcano occurred in 2015: on 07, 12, and 15 January, 01, 17, and 28 February, 04, 08, 16, 21-22, and 26 March, 07 and 12 April: ash plumes rose up to 7-12 km a.s.l. and extended more 900 km to the different directions of the volcano. Ashfalls occurred at Ust'-Kamchatsk on 16 March, and Klyuchi on 30 October. Strong and moderate hot avalanches from the lava dome were observing more often in the second half of the year. Aviation color code of Sheveluch was Orange during the year. Activity of the volcano was dangerous to international and local aviation. Explosive-effusive eruption of Klyuchevskoy volcano lasted from 01 January till 24 March. Strombolian explosive volcanic activity began from 01 January, and on 08-09 January a lava flow was detected at the Apakhonchich chute on the southeastern flank of the volcano. Vulcanian activity of the volcano began from 10 January. Ashfalls occurred on 11 and 28 January, and 07 February at Kozyrevsk; and on 21 and 27 January, 05, 11, and 13-16 February at Klyuchi. Paroxysmal phase of the eruption displayed on 15 February: explosions sent ash up to 8 km a.s.l. during five hours, ash plumes drifted for about 1000 km mainly to the eastern directions of the volcano. A thermal anomaly began to noting at satellite images again from 28 August; and it was registering time to time till 31 December. Aviation color code of the volcano was Yellow on 01-11 January; Orange from 11 January to 15 February; Red on 15 February; Orange from 15 February to 25 March; Yellow from 25 March till 06 April; Green on 06-14 April; Yellow on 14-18 April; Orange on 18-26 April; Yellow from 26 April to 05 May; Orange on 05-13 May; Yellow from 13 May to 20 July; Green from 20 July to 28 August; Yellow from 28 August to 31 December. Activity of the volcano was dangerous to international and local aviation. Karymsky volcano has been in a state of explosive eruption since 1996. The moderate ash explosions of this volcano were noting during the year, ash plumes rose up to 5 km a.s.l. and extended more 300 km mainly to the eastern directions of the volcano. Aviation color code of the volcano was Orange during the year. Activity of the volcano was dangerous to local aviation. Explosive eruption of Zhupanovsky volcano began on 06 June, 2014, and finished 30 November, 2015. Explosions sent ash up to 8-11 km a.s.l. on 07-08 and 25 March, 12 July, and 30 November; and in the other days - up to 3.5-6 km a.s.l. Ash plumes extended for about 1200 km mainly to the eastern directions of the volcano. In the periods from 26 January to 06 February, 09-15 February, 23 February - 01 March, from 25 March to 03 April, from 04 April to 20 May, from 21 May to 08 June, from 16 June to 12 July, from 15 July to 27 November, the volcano was in a state of relative calm. The culminations of the 2014-2015 eruption of the volcano were explosions and collapses of parts of Priemysh active cone on 12 and 14 July, and 30 November, 2015. Aviation color code of the volcano was Orange from 01 January to 16 May; Yellow from 16 May to 08 June; Orange from 08 June to 19 July; Yellow on 19-20 July; Green from 20 July to 27 November; Orange from 27 November to 10 December; Yellow on 10-17 December; and Green on 17-31 December. Activity of the volcano was dangerous to international and local aviation. The eruptive activity of Chikurachki volcano lasted on 15-19 February. First explosions sent ash up to 7.5 km a.s.l., but later ash plumes drifted on the height about 3-4 km a.s.l. from the volcano. Aviation color code of the volcano was Orange during 16-22 February, and Yellow on 22-26 February. Activity of the volcano was dangerous to local aviation. The intensive thermal anomaly over Alaid volcano was detecting at satellite images from 01 October till 31 December. Aviation color code of the volcano was Yellow during this time. A strong gas-steam activity of the volcano sometimes was observing. Activity of the volcano was dangerous to local aviation.

Characteristics and petrology of the effusive-explosive activity of Colima volcano, in the years 2015-2017

NASA Astrophysics Data System (ADS)

Suarez-Plascencia, C.; Nuñez-Cornu, F. J.; Arreola-Ochoa, L. C.; Suarez, G. B. V.; Carrillo-Gonzalez, D. A.

2017-12-01

The Colima volcano, during the years 2015-2017, presented an important effusive and explosive activity, which began in January 2015 with the growth of a dome that was destroyed by explosions, forming pyroclastic flows reaching distances of up to 2 km by the north and south flanks of the volcano. In May a new dome was extruded, forming three thick lava flows along the northern and southern slopes; the extruded volume was approximately 6 million cubic meters, with a rate in 52 days of 1.3 m3/sec. On July 11 merapi flows were formed it flowed through by the ravines of Montegrande and San Antonio, on the south and southwest flank, reaching distances of 10.4 km. The following days the activity had decreased substantially, leaving a crater of 60 m of depth and 270 m of diameter. In February 2016, a small dome occupied the central part of the main crater, and it was until September that an episode of volcanic tremor began, that was associated with its rapid growth, which in 48 hours filled the crater and formed a lava flow that descended by the south slope. By October 2, 2.3 million m3 of lava were extruded, which caused a deflation of the dome. In October 7, the volcano emitted a great amount of gases and steam of water that formed an acid rain that affected forests and crops of the south and southwest slope, causing losses by 1 million dollars. In November, a series of explosions occurred that destroyed two thirds of the dome. In January 2017, the explosive activity increased and again destroyed the dome. Five events were recorded that reached between 3 km and 4 km of height on the top of the volcano, the dispersion of the ash generally went to the northeast, reaching distances of up to 200 km. Currently the volcano is sustaining reduced seismic and fumarole activity. In 2005, 2015 and 2017, the geochemical analysis of major elements such as SiO2 from the ash emitted by the volcano showed an increase from 54.51% to 60.05% and 60.24%, respectively, which was associated with the increase in volcanic explosions, affecting and causing damages to the economic activities and the localities and settlements in its valleys and piedmont.

Measuring the Progenitor Masses and Dense Circumstellar Material of Type II Supernovae

NASA Astrophysics Data System (ADS)

Morozova, Viktoriya; Piro, Anthony L.; Valenti, Stefano

2018-05-01

Recent modeling of hydrogen-rich Type II supernova (SN II) light curves suggests the presence of dense circumstellar material (CSM) surrounding the exploding progenitor stars. This has important implications for the activity and structure of massive stars near the end of their lives. Since previous work focused on just a few events, here we expand to a larger sample of 20 well-observed SNe II. For each event we are able to constrain the progenitor zero-age main-sequence (ZAMS) mass, explosion energy, and the mass and radial extent of the dense CSM. We then study the distribution of each of these properties across the full sample of SNe. The inferred ZAMS masses are found to be largely consistent with a Salpeter distribution with minimum and maximum masses of 10.4 and 22.9 M ⊙, respectively. We also compare the individual ZAMS masses we measure with specific SNe II that have pre-explosion imaging to check their consistency. Our masses are generally comparable to or higher than the pre-explosion imaging masses, potentially helping ease the red supergiant problem. The explosion energies vary from (0.1–1.3) × 1051 erg, and for ∼70% of the SNe we obtain CSM masses in the range between 0.18 and 0.83 M ⊙. We see a potential correlation between the CSM mass and explosion energy, which suggests that pre-explosion activity has a strong impact on the structure of the star. This may be important to take into account in future studies of the ability of the neutrino mechanism to explode stars. We also see a possible correlation between the CSM radial extent and ZAMS mass, which could be related to the time with respect to explosion when the CSM is first generated.

Explosions of andesitic volcanoes in Kamchatka and danger of volcanic ash clouds to aviation

NASA Astrophysics Data System (ADS)

Gordeev, E. I.; Girina, O. A.; Neal, C. A.

2010-12-01

There are 30 active volcanoes in Kamchatka and 4 of them continuously active. The explosions of andesitic volcanoes (Bezymianny and Sheveluch) produce strong and fast ash plumes, which can rich high altitude (up to 15 km) in short time. Bezymianny and Sheveluch are the most active volcanoes of Kamchatka. A growth of the lava dome of Bezymianny into the explosive crater continues from 1956 till present. Nine strong explosive eruptions of the volcano associated with the dome-building activity occurred for last 5 years in: 2005, January 11 and November 30; 2006, May 09 and December 24; 2007, May 11 and October 14-15; 2008, August 19; 2009, December 16-17 and 2010, May 31. Since 1980, a lava dome of Sheveluch has being growing at the bottom of the explosive crater, which has formed as the result of the catastrophic eruption in 1964. Strong explosive eruptions of the volcano associated with the dome-building activity occurred in: 1993, April 22; 2001, May 19-21; 2004, May 09; 2005, February 27 and September 22; 2006, December 25-26; 2007, March 29 and December 19; 2009, April 26-28 and September 10-11. Strong explosive eruption of andesitic 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. Volcanic ash is an extremely abrasive, as it consists of acute-angled rock fragments and volcanic glass. Due to the high specific surface of andesitic ash particles are capable of retaining an electrostatic charge and absorb droplets of water and corrosive acids. 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. To reduce the risk of collision of aircraft with ash clouds of Kamchatkan volcanoes, was created the International KVERT Project, uniting scientists IVS FEB RAS, KB GS RAS and AVO USGS. To solve this problem and provide early warning of air services on the volcanic hazard, scientists analyze the data of seismic, video, visual and satellite monitoring of volcanoes of Kamchatka. In case of ash explosion, cloud or plume detection, information is sending via e-mail operatively to all interested users. Scientists collect all the information (research data, descriptions of eruptions from the literature, observations of tourists, etc.) of the active volcanoes. Based on analysis of historical activity Bezymianny, as well as its continuous monitoring data, scientists of KVERT Project repeatedly predicted the eruption of this volcano. It allowed notifying in time air services of the impending danger of aircraft. For example, in 2001-2010, were predicted 9 of its eruptions (December 16, 2001; December 25, 2002; January 11, 2005; May 9, 2006; May 11, 2007; October 14-15, 2007; August 19, 2008; December 16, 2009; May 31, 2010).

77 FR 32136 - Agency Information Collection Activities:

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-31

... Fire Safety Authority of Storage of Explosive Materials. (3) Agency form number, if any, and the... safety of emergency response personnel responding to fires at sites where explosives are stored. The information is provided both orally and in writing to the authority having jurisdiction for fire safety in the...

SUPERFUND TREATABILITY CLEARINGHOUSE: INCINERATION TEST OF EXPLOSIVES CONTAMINATED SOILS AT SAVANNA ARMY DEPOT ACTIVITY, SAVANNA, ILLINOIS

EPA Science Inventory

The primary objective of these tests was to demonstrate the effectiveness of incineration as a decontamination method for explosives contaminated sails. A pilot-scale rotary kiln incinerator, manufactured by ThermAll, Inc., was used to treat both sandy and clayey...

77 FR 1510 - Agency Information Collection Activities: Proposed Collection; Comments Requested; Firearms...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-10

... Services Division Customer Service Survey ACTION: 60-Day Notice of Information Collection. The Department... & Explosives Services Division Customer Service Survey. (3) Agency form number, if any, and the applicable... firearms and explosives industry. This anonymous survey would allow FESD to gauge customer satisfaction and...

49 CFR 172.202 - Description of hazardous material on shipping papers.

Code of Federal Regulations, 2010 CFR

2010-10-01

... HAZARDOUS MATERIALS TABLE, SPECIAL PROVISIONS, HAZARDOUS MATERIALS COMMUNICATIONS, EMERGENCY RESPONSE... description must be indicated (by mass or volume, or by activity for Class 7 materials) and must include an... mass. For an explosive that is an article, such as Cartridges, small arms, the net explosive mass may...

77 FR 70471 - Agency Information Collection Activities: Proposed Collection; Comments Requested; Furnishing of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-26

... importers and persons who manufacture or import explosive materials or ammonium nitrate must, when required by the Director, furnish samples of such explosive materials or ammonium nitrate; information on... to the identification of the ammonium nitrate. (5) An estimate of the total number of respondents and...

77 FR 57593 - Agency Information Collection Activities: Proposed Collection; Comments Requested: Furnishing of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-18

... import explosive materials or ammonium nitrate must, when required by the Director, furnish samples of such explosive materials or ammonium nitrate; information on chemical composition of those products... ammonium nitrate. (5) An estimate of the total number of respondents and the amount of time estimated for...

Critical Homeland Infrastructure Protection

DTIC Science & Technology

2007-01-01

talent. Examples include: * Detection of surveillance activities; * Stand-off detection of chemical, biological, nuclear, radiation and explosive ...Manager Guardian DARPA Overview Mr. Roger Gibbs DARPA LLNL Technologies in Support of Infrastructure Mr. Don Prosnitz LLNL Protection Sandia National...FP Antiterrorism/Force Protection CBRNE Chemical Biological Radiological Nuclear Explosive CERT Commuter Emergency Response Team CIA Central

Modeling a High Explosive Cylinder Experiment

NASA Astrophysics Data System (ADS)

Zocher, Marvin A.

2017-06-01

Cylindrical assemblies constructed from high explosives encased in an inert confining material are often used in experiments aimed at calibrating and validating continuum level models for the so-called equation of state (constitutive model for the spherical part of the Cauchy tensor). Such is the case in the work to be discussed here. In particular, work will be described involving the modeling of a series of experiments involving PBX-9501 encased in a copper cylinder. The objective of the work is to test and perhaps refine a set of phenomenological parameters for the Wescott-Stewart-Davis reactive burn model. The focus of this talk will be on modeling the experiments, which turned out to be non-trivial. The modeling is conducted using ALE methodology.

Long-term prospects: Mitigation of supernova and gamma-ray burst threat to intelligent beings

NASA Astrophysics Data System (ADS)

Ćirković, Milan M.; Vukotić, Branislav

2016-12-01

We consider global catastrophic risks due to cosmic explosions (supernovae, magnetars and gamma-ray bursts) and possible mitigation strategies by humans and other hypothetical intelligent beings. While by their very nature these events are so huge to daunt conventional thinking on mitigation and response, we wish to argue that advanced technological civilizations would be able to develop efficient responses in the domain of astroengineering within their home planetary systems. In particular, we suggest that construction of shielding swarms of small objects/particles confined by electromagnetic fields could be one way of mitigating the risk of cosmic explosions and corresponding ionizing radiation surges. Such feats of astroengineering could, in principle, be detectable from afar by advanced Dysonian SETI searches.

Long-times series of infrasonic records at open-vents volcanoes (Yasur volcano, Vanuatu, 2003-2014): the remarkable temporal stability of magma viscosity

NASA Astrophysics Data System (ADS)

Vergniolle, S.; Souty, V.; Zielinski, C.; Bani, P.; LE Pichon, A.; Lardy, M.; Millier, P.; Herry, P.; Todman, S.; Garaebiti, E.

2017-12-01

Open-vents volcanoes, often presenting series of Strombolian explosions of various intensity, are responding, although with a delay, to any changes in the degassing pattern, providing a quasi-direct route to processes at depth. Open-vents volcanoes display a persistent volcanic activity, although of variable intensity. Long-times series at open-vents volcanoes could therefore be key measurements to unravel physical processes at the origin of Strombolian explosions and be crucial for monitoring. Continuous infrasonic records can be used to estimate the gas volume expelled at the vent during explosions (bursting of a long slug). The gas volume of each explosion is deduced from a series of two successive integrations of acoustic pressure (monopole). Here we analysed more than 4 years of infrasonic records at Yasur volcano (Vanuatu), spanning between 2003 and 2014 and organised into 8 main quasi-continuous periods. The relationship between the gas volume of each explosion and its associated maximum positive acoustic pressure, a proxy for the inner gas overpressure at bursting, shows a remarkably stable trend over the 8 periods. Two main trends exists, one which covers the full range of acoustic pressures (called « strong explosions ») and the second which represents explosions with a large gas volume and mild acoustic pressure. The class of « strong explosions » clearly follows the model of Del Bello et al. (2012), which shows that the inner gas overpressure at bursting, here empirically measured by the maximum acoustic pressure, is proportional to the gas volume. Constrains on magma viscosity and conduit radius, are deduced from this trend and from the gas volume at the transition passive-active degassing. The remarkable stability of this trend over time suggests that 1) the magma viscosity is stable at the depth where gas overpressure is produced within the slug and 2) any potential changes in magma viscosity occur very close to the top of the magma column.

What factors control superficial lava dome explosivity?

PubMed

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

2015-09-30

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

What factors control superficial lava dome explosivity?

PubMed Central

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

2015-01-01

Dome-forming eruption is a frequent eruptive style and a major hazard on numerous volcanoes worldwide. Lava domes are built by slow extrusion of degassed, viscous magma and may be destroyed by gravitational collapse or explosion. The triggering of lava dome explosions is poorly understood: here we propose a new model of superficial lava-dome explosivity based upon a textural and geochemical study (vesicularity, microcrystallinity, cristobalite distribution, residual water contents, crystal transit times) of clasts produced by key eruptions. Superficial explosion of a growing lava dome may be promoted through porosity reduction caused by both vesicle flattening due to gas escape and syn-eruptive cristobalite precipitation. Both processes generate an impermeable and rigid carapace allowing overpressurisation of the inner parts of the lava dome by the rapid input of vesiculated magma batches. The relative thickness of the cristobalite-rich carapace is an inverse function of the external lava dome surface area. Explosive activity is thus more likely to occur at the onset of lava dome extrusion, in agreement with observations, as the likelihood of superficial lava dome explosions depends inversely on lava dome volume. This new result is of interest for the whole volcanological community and for risk management. PMID:26420069

Explosive particle soil surface dispersion model for detonated military munitions.

PubMed

Hathaway, John E; Rishel, Jeremy P; Walsh, Marianne E; Walsh, Michael R; Taylor, Susan

2015-07-01

The accumulation of high explosive mass residue from the detonation of military munitions on training ranges is of environmental concern because of its potential to contaminate the soil, surface water, and groundwater. The US Department of Defense wants to quantify, understand, and remediate high explosive mass residue loadings that might be observed on active firing ranges. Previously, efforts using various sampling methods and techniques have resulted in limited success, due in part to the complicated dispersion pattern of the explosive particle residues upon detonation. In our efforts to simulate particle dispersal for high- and low-order explosions on hypothetical firing ranges, we use experimental particle data from detonations of munitions from a 155-mm howitzer, which are common military munitions. The mass loadings resulting from these simulations provide a previously unattained level of detail to quantify the explosive residue source-term for use in soil and water transport models. In addition, the resulting particle placements can be used to test, validate, and optimize particle sampling methods and statistical models as applied to firing ranges. Although the presented results are for a hypothetical 155-mm howitzer firing range, the method can be used for other munition types once the explosive particle characteristics are known.

Dynamics of vapor emissions at wire explosion thresholda)

NASA Astrophysics Data System (ADS)

Belony, Paul A.; Kim, Yong W.

2010-10-01

X-pinch plasmas have been actively studied in the recent years. Numerical simulation of the ramp-up of metallic vapor emissions from wire specimens shows that under impulsive Ohmic heating the wire core invariably reaches a supercritical state before explosion. The heating rate depends sensitively on the local wire resistance, leading to highly variable vapor emission flux along the wire. To examine the vapor emission process, we have visualized nickel wire explosions by means of shock formation in air. In a single explosion as captured by shadowgraphy, there usually appear several shocks with spherical or cylindrical wave front originating from different parts of the wire. Growth of various shock fronts in time is well characterized by a power-law scaling in one form or another. Continuum emission spectra are obtained and calibrated to measure temperature near the explosion threshold. Shock front structures and vapor plume temperature are examined.

Hot-spot contributions in shocked high explosives from mesoscale ignition models

NASA Astrophysics Data System (ADS)

Levesque, G.; Vitello, P.; Howard, W. M.

2013-06-01

High explosive performance and sensitivity is strongly related to the mesoscale defect densities. Bracketing the population of mesoscale hot spots that are active in the shocked ignition of explosives is important for the development of predictive reactive flow models. By coupling a multiphysics-capable hydrodynamics code (ale3d) with a chemical kinetics solver (cheetah), we can parametrically analyze different pore sizes undergoing collapse in high pressure shock conditions with evolving physical parameter fields. Implementing first-principles based decomposition kinetics, burning hot spots are monitored, and the regimes of pore sizes that contribute significantly to burnt mass faction and those that survive thermal conduction on the time scales of ignition are elucidated. Comparisons are drawn between the thermal explosion theory and the multiphysics models for the determination of nominal pore sizes that burn significantly during ignition for the explosive 1,3,5-triamino-2,4,6-trinitrobenzene.

Explosive cell lysis as a mechanism for the biogenesis of bacterial membrane vesicles and biofilms

PubMed Central

Turnbull, Lynne; Toyofuku, Masanori; Hynen, Amelia L.; Kurosawa, Masaharu; Pessi, Gabriella; Petty, Nicola K.; Osvath, Sarah R.; Cárcamo-Oyarce, Gerardo; Gloag, Erin S.; Shimoni, Raz; Omasits, Ulrich; Ito, Satoshi; Yap, Xinhui; Monahan, Leigh G.; Cavaliere, Rosalia; Ahrens, Christian H.; Charles, Ian G.; Nomura, Nobuhiko; Eberl, Leo; Whitchurch, Cynthia B.

2016-01-01

Many bacteria produce extracellular and surface-associated components such as membrane vesicles (MVs), extracellular DNA and moonlighting cytosolic proteins for which the biogenesis and export pathways are not fully understood. Here we show that the explosive cell lysis of a sub-population of cells accounts for the liberation of cytosolic content in Pseudomonas aeruginosa biofilms. Super-resolution microscopy reveals that explosive cell lysis also produces shattered membrane fragments that rapidly form MVs. A prophage endolysin encoded within the R- and F-pyocin gene cluster is essential for explosive cell lysis. Endolysin-deficient mutants are defective in MV production and biofilm development, consistent with a crucial role in the biogenesis of MVs and liberation of extracellular DNA and other biofilm matrix components. Our findings reveal that explosive cell lysis, mediated through the activity of a cryptic prophage endolysin, acts as a mechanism for the production of bacterial MVs. PMID:27075392

The challenge of improvised explosives

DOE PAGES

Maienschein, Jon L.

2012-06-14

Energetic materials have been developed for decades, and indeed centuries, with a common set of goals in mind. Performance (as a detonating explosive, a propellant, or a pyrotechnic) has always been key, equally important have been the attributes of safety, stability, and reproducibility. Research and development with those goals has led to the set of energetic materials commonly used today. In the past few decades, the adoption and use of improvised explosives in attacks by terrorists or third-world parties has led to many questions about these materials, e.g., how they may be made, what threat they pose to the intendedmore » target, how to handle them safely, and how to detect them. The unfortunate advent of improvised explosives has opened the door for research into these materials, and there are active programs in many countries. I will discuss issues and opportunities facing research into improvised explosives.« less

Neural activation during risky decision-making in youth at high risk for substance use disorders.

PubMed

Hulvershorn, Leslie A; Hummer, Tom A; Fukunaga, Rena; Leibenluft, Ellen; Finn, Peter; Cyders, Melissa A; Anand, Amit; Overhage, Lauren; Dir, Allyson; Brown, Joshua

2015-08-30

Risky decision-making, particularly in the context of reward-seeking behavior, is strongly associated with the presence of substance use disorders (SUDs). However, there has been little research on the neural substrates underlying reward-related decision-making in drug-naïve youth who are at elevated risk for SUDs. Participants comprised 23 high-risk (HR) youth with a well-established SUD risk phenotype and 27 low-risk healthy comparison (HC) youth, aged 10-14. Participants completed the balloon analog risk task (BART), a task designed to examine risky decision-making, during functional magnetic resonance imaging. The HR group had faster reaction times, but otherwise showed no behavioral differences from the HC group. HR youth experienced greater activation when processing outcome, as the chances of balloon explosion increased, relative to HC youth, in ventromedial prefrontal cortex (vmPFC). As explosion probability increased, group-by-condition interactions in the ventral striatum/anterior cingulate and the anterior insula showed increasing activation in HR youth, specifically on trials when explosions occurred. Thus, atypical activation increased with increasing risk of negative outcome (i.e., balloon explosion) in a cortico-striatal network in the HR group. These findings identify candidate neurobiological markers of addiction risk in youth at high familial and phenotypic risk for SUDs. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

A Rose by Naming: How We May Learn How to Do It

ERIC Educational Resources Information Center

Greer, R. Douglas; Longano, Jennifer

2010-01-01

Naming appears to be the source of the explosion in language development and involves the integration of the initially separate listener and speaker responses. This integration has a role in the development of reading, writing, and the following and construction of verbal algorithms that make types of complex human behavior possible. Considerable…

Environmental Assessment: Explosive Ordnance Disposal Mission Beddown Minneapolis-St. Paul Air Reserve Station Minneapolis, Minnesota

DTIC Science & Technology

2011-04-01

training area. The baseball/ softball field adjacent to Building 750. A parking lot and storage area on station property leased to the Minnesota Air...was constructed on this site to help reduce storm water runoff volume at MSPARS. The baseball/ softball field adjacent to Building 750. Site is the

49 CFR 176.133 - Magazine stowage Type C.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Magazine stowage Type C. 176.133 Section 176.133... Requirements for Class 1 (Explosive) Materials Stowage § 176.133 Magazine stowage Type C. The construction requirements for magazine stowage type C are the same as for a closed cargo transport unit in § 176.63(e). In...

Contraction type influences the human ability to use the available torque capacity of skeletal muscle during explosive efforts

PubMed Central

Tillin, Neale A.; Pain, Matthew T. G.; Folland, Jonathan P.

2012-01-01

The influence of contraction type on the human ability to use the torque capacity of skeletal muscle during explosive efforts has not been documented. Fourteen male participants completed explosive voluntary contractions of the knee extensors in four separate conditions: concentric (CON) and eccentric (ECC); and isometric at two knee angles (101°, ISO101 and 155°, ISO155). In each condition, torque was measured at 25 ms intervals up to 150 ms from torque onset, and then normalized to the maximum voluntary torque (MVT) specific to that joint angle and angular velocity. Explosive voluntary torque after 50 ms in each condition was also expressed as a percentage of torque generated after 50 ms during a supramaximal 300 Hz electrically evoked octet in the same condition. Explosive voluntary torque normalized to MVT was more than 60 per cent larger in CON than any other condition after the initial 25 ms. The percentage of evoked torque expressed after 50 ms of the explosive voluntary contractions was also greatest in CON (ANOVA; p < 0.001), suggesting higher concentric volitional activation. This was confirmed by greater agonist electromyography normalized to Mmax (recorded during the explosive voluntary contractions) in CON. These results provide novel evidence that the ability to use the muscle's torque capacity explosively is influenced by contraction type, with concentric contractions being more conducive to explosive performance due to a more effective neural strategy. PMID:22258636

The safety and reliability of the S and A mechanism designed for the NASA/LSPE program

NASA Technical Reports Server (NTRS)

Montesi, L. J.

1973-01-01

Under contract to the Manned Spacecraft Center, NASA/Houston, NOL developed a number of explosive charges for use in studying the surface of the moon during Apollo 17 activities. The charges were part of the Lunar Seismic Profiling Experiment (LSPE). When the Safety and Arming Device used in the previous ALSEP experiments was found unsuitable for use with the new explosive packages, NOL also designed the Safety and Arming Mechanism, and the safety and reliability tests conducted are described. The results of the test program indicate that the detonation transfer probability between the armed explosive components exceeds 0.9999, and is less than 0.0001 when the explosive components are in the safe position.

Seismic data acquisition at the FACT site for the CASPAR project.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, Kyle R.; Chael, Eric Paul; Hart, Darren M.

Since May 2010, we have been recording continuous seismic data at Sandia's FACT site. The collected signals provide us with a realistic archive for testing algorithms under development for local monitoring of explosive testing. Numerous small explosive tests are routinely conducted around Kirtland AFB by different organizations. Our goal is to identify effective methods for distinguishing these events from normal daily activity on and near the base, such as vehicles, aircraft, and storms. In this report, we describe the recording system, and present some observations of the varying ambient noise conditions at FACT. We present examples of various common, non-explosive,more » sources. Next we show signals from several small explosions, and discuss their characteristic features.« less

Analysis of Spattering Activity at Halema'uma'u in 2015

NASA Astrophysics Data System (ADS)

Mintz, Bianca G.

The classical explosive basaltic eruption spectrum is traditionally defined by the following end member eruption styles: Hawaiian and Strombolian. The field use of high-speed cameras has enabled volcanologists to make improved quantifications and more accurate descriptions of these classical eruptions styles and to quantify previously undecipherable activity (including activity on the basaltic eruption spectrum between the two defined end members). Explosive activity in 2015 at the free surface of the Halema'uma'u lava lake at Kilauea exhibited features of both sustained (Hawaiian) fountaining and transient (Strombolian) explosivity. Most of this activity is internally triggered by the internal rise of decoupled gas bubbles from below the lake's surface, but external triggering via rock falls, was also observed. Here I identify three styles of bubble bursting and spattering eruptive activity (isolated events, clusters of events, and prolonged episodes) at the lava lake, and distinguished them based on their temporal and spatial distributions. Isolated events are discrete single bubble bursts that persist for a few tenths of seconds to seconds and are separated by repose periods of similar or longer time scales. Cluster of events are closely spaced, repeated events grouped around a narrow point source, which persist for seconds to minutes. Prolonged episodes are groupings of numerous events closely linked in space and time that persist for tens of minutes to hours. Analysis of individual events from high-speed camera images indicates that they are made up of up to three phases: the bubble ascent phase, the bursting and pyroclast ejection phase, and the drain back (and rebound) phase. Based on the numerical parameters established in this study, the 2015 activity was relatively weak (i.e., of low intensity) but still falls in a region between those of continuous Hawaiian fountains and impulsive, short-lived Strombolian explosions, in terms of duration.

Short-Period Surface Wave Based Seismic Event Relocation

NASA Astrophysics Data System (ADS)

White-Gaynor, A.; Cleveland, M.; Nyblade, A.; Kintner, J. A.; Homman, K.; Ammon, C. J.

2017-12-01

Accurate and precise seismic event locations are essential for a broad range of geophysical investigations. Superior location accuracy generally requires calibration with ground truth information, but superb relative location precision is often achievable independently. In explosion seismology, low-yield explosion monitoring relies on near-source observations, which results in a limited number of observations that challenges our ability to estimate any locations. Incorporating more distant observations means relying on data with lower signal-to-noise ratios. For small, shallow events, the short-period (roughly 1/2 to 8 s period) fundamental-mode and higher-mode Rayleigh waves (including Rg) are often the most stable and visible portion of the waveform at local distances. Cleveland and Ammon [2013] have shown that teleseismic surface waves are valuable observations for constructing precise, relative event relocations. We extend the teleseismic surface wave relocation method, and apply them to near-source distances using Rg observations from the Bighorn Arche Seismic Experiment (BASE) and the Earth Scope USArray Transportable Array (TA) seismic stations. Specifically, we present relocation results using short-period fundamental- and higher-mode Rayleigh waves (Rg) in a double-difference relative event relocation for 45 delay-fired mine blasts and 21 borehole chemical explosions. Our preliminary efforts are to explore the sensitivity of the short-period surface waves to local geologic structure, source depth, explosion magnitude (yield), and explosion characteristics (single-shot vs. distributed source, etc.). Our results show that Rg and the first few higher-mode Rayleigh wave observations can be used to constrain the relative locations of shallow low-yield events.

Rapid and slow: Varying magma ascent rates as a mechanism for Vulcanian explosions

NASA Astrophysics Data System (ADS)

Cassidy, Mike; Cole, Paul. D.; Hicks, Kelby E.; Varley, Nick R.; Peters, Nial; Lerner, Allan H.

2015-06-01

Vulcanian explosions are one of the most common types of volcanic activity observed at silicic volcanoes. Magma ascent rates are often invoked as being the fundamental control on their explosivity, yet this factor is poorly constrained for low magnitude end-member Vulcanian explosions, which are particularly poorly understood, partly due to the rarity of ash samples and low gas fluxes. We describe ash generated by small Vulcanian explosions at Volcán de Colima in 2013, where we document for the first time marked differences in the vesicularity, crystal characteristics (volume fraction, size and shape) and glass compositions in juvenile material from discrete events. We interpret these variations as representing differing ascent styles and speeds of magma pulses within the conduit. Heterogeneous degassing during ascent leads to fast ascending, gas-rich magma pulses together with slow ascending gas-poor magma pulses within the same conduit. This inferred heterogeneity is complemented by SO2 flux data, which show transient episodes of both open and closed system degassing, indicating efficient shallow fracture sealing mechanisms, which allows for gas overpressure to generate small Vulcanian explosions.

Eruptions of Mount St. Helens : Past, present, and future

USGS Publications Warehouse

Tilling, Robert I.; Topinka, Lyn J.; Swanson, Donald A.

1990-01-01

Mount St. Helens, located in southwestern Washington about 50 miles northeast of Portland, Oregon, is one of several lofty volcanic peaks that dominate the Cascade Range of the Pacific Northwest; the range extends from Mount Garibaldi in British Columbia, Canada, to Lassen Peak in northern California. Geologists call Mount St. Helens a composite volcano (or stratovolcano), a term for steepsided, often symmetrical cones constructed of alternating layers of lava flows, ash, and other volcanic debris. Composite volcanoes tend to erupt explosively and pose considerable danger to nearby life and property. In contrast, the gently sloping shield volcanoes, such as those in Hawaii, typically erupt nonexplosively, producing fluid lavas that can flow great distances from the active vents. Although Hawaiian-type eruptions may destroy property, they rarely cause death or injury. Before 1980, snow-capped, gracefully symmetrical Mount St. Helens was known as the "Fujiyama of America." Mount St. Helens, other active Cascade volcanoes, and those of Alaska form the North American segment of the circum-Pacific "Ring of Fire," a notorious zone that produces frequent, often destructive, earthquake and volcanic activity.

A Comparison of ACQ, AIE and AEE-Based Polymers Loaded on Polyurethane Foams as Sensors for Explosives Detection.

PubMed

Chu, Zhiwei; Fan, Zhuxin; Zhang, Xiang; Tan, Xiaofeng; Li, Dongxu; Chen, Guohua; Zhao, Qinghua

2018-05-15

An aggregation-caused quenching (ACQ)-active polymer (PF), an aggregation-induced emission (AIE)-active polymer (PFTPE) and an aggregation-enhanced emission (AEE)-active polymer (PTTPE) were synthesized by tetraphenylethane (TPE), fluorene and thiophene moieties. Polyurethane (PU) foams modified by PF, PFTPE and PTTPE, namely PU-PF, PU-PFTPE and PU-PTTPE, using ultrasonication-assisted method have been prepared. A comparative study of PU-PF, PU-PFTPE and PU-PTTPE for detection explosives had been performed, and significant fluorescence quenching was observed with the introduction of PA solutions. The as-prepared PU-PF, PU-PFTPE and PU-PTTPE sensors exhibited a superior sensitivity for PA solutions with different concentrations. Remarkably, PU-PF gave a quenching efficiency of 96.2%, higher than 93.5% for PU-PFTPE and 86.7% for PU-PTTPE at a PA concentration of 180 µg·mL -1 in methanol, which was attributed to the effective energy transfer from the fluorophore (PF) to the nitro explosive (PA). This suggested that some ACQ polymers, applied to detect explosives, could afford better performances than AIE or AEE polymers through modification of structures and selection of adequate carriers. At the same time, these chemical sensors can be recycled many times.

A Comparison of ACQ, AIE and AEE-Based Polymers Loaded on Polyurethane Foams as Sensors for Explosives Detection

PubMed Central

Chu, Zhiwei; Fan, Zhuxin; Zhang, Xiang; Tan, Xiaofeng; Chen, Guohua; Zhao, Qinghua

2018-01-01

An aggregation-caused quenching (ACQ)-active polymer (PF), an aggregation-induced emission (AIE)-active polymer (PFTPE) and an aggregation-enhanced emission (AEE)-active polymer (PTTPE) were synthesized by tetraphenylethane (TPE), fluorene and thiophene moieties. Polyurethane (PU) foams modified by PF, PFTPE and PTTPE, namely PU-PF, PU-PFTPE and PU-PTTPE, using ultrasonication-assisted method have been prepared. A comparative study of PU-PF, PU-PFTPE and PU-PTTPE for detection explosives had been performed, and significant fluorescence quenching was observed with the introduction of PA solutions. The as-prepared PU-PF, PU-PFTPE and PU-PTTPE sensors exhibited a superior sensitivity for PA solutions with different concentrations. Remarkably, PU-PF gave a quenching efficiency of 96.2%, higher than 93.5% for PU-PFTPE and 86.7% for PU-PTTPE at a PA concentration of 180 µg·mL−1 in methanol, which was attributed to the effective energy transfer from the fluorophore (PF) to the nitro explosive (PA). This suggested that some ACQ polymers, applied to detect explosives, could afford better performances than AIE or AEE polymers through modification of structures and selection of adequate carriers. At the same time, these chemical sensors can be recycled many times. PMID:29762497

Detecting hidden volcanic explosions from Mt. Cleveland Volcano, Alaska with infrasound and ground-couples airwaves

USGS Publications Warehouse

De Angelis, Slivio; Fee, David; Haney, Matthew; Schneider, David

2012-01-01

In Alaska, where many active volcanoes exist without ground-based instrumentation, the use of techniques suitable for distant monitoring is pivotal. In this study we report regional-scale seismic and infrasound observations of volcanic activity at Mt. Cleveland between December 2011 and August 2012. During this period, twenty explosions were detected by infrasound sensors as far away as 1827 km from the active vent, and ground-coupled acoustic waves were recorded at seismic stations across the Aleutian Arc. Several events resulting from the explosive disruption of small lava domes within the summit crater were confirmed by analysis of satellite remote sensing data. However, many explosions eluded initial, automated, analyses of satellite data due to poor weather conditions. Infrasound and seismic monitoring provided effective means for detecting these hidden events. We present results from the implementation of automatic infrasound and seismo-acoustic eruption detection algorithms, and review the challenges of real-time volcano monitoring operations in remote regions. We also model acoustic propagation in the Northern Pacific, showing how tropospheric ducting effects allow infrasound to travel long distances across the Aleutian Arc. The successful results of our investigation provide motivation for expanded efforts in infrasound monitoring across the Aleutians and contributes to our knowledge of the number and style of vulcanian eruptions at Mt. Cleveland.

Empirical Calibration of Small Explosion Seismic And Acoustic Phenomenology in New England

DTIC Science & Technology

2008-10-31

site was too close to a nearby cell /radio tower and the active quarry wall to detonate our planned 400 lb explosions. Core drilling at an...alternative test site (Figure 52) was conducted further away from the active quarry wall and a nearby cell /radio tower. The alternative site would be far...experiment was returned into the original location (Figure 52). In order to reduce the projected ground vibrations at the cell /radio tower and high

The Inglorious Death of Jumbo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meade, Roger Allen

In the summer of 1944, J. Robert Oppenheimer and Los Alamos faced a crisis. An isotopic impurity in Plutonium rendered the metal unusable in a gun-assembled atomic bomb (i.e., Little Boy). Making this situation worse was a shortage of Uranium. The combination of these two problems threatened the entire wartime project. The answer to this dilemma, in part, was to develop a novel assembly method for Plutonium using the supersonic shock waves created by several tons of high explosives to compress a ball of Plutonium into a supercritical state. Since this method, implosion, was not much more than a theoreticalmore » construct, the Trinity test was devised to proof test the process. Given the speculative nature of implosion, Trinity was a gamble of sorts. If the test failed (i.e., little or no nuclear yield), the blast of the high explosives would scatter the scarce and expensive Plutonium over the surrounding desert. Since the probability of failure remained high into the early summer of 1945, some method of containing a failed nuclear explosion was needed. Jumbo was the answer.« less

Manufacture of dissolving pulps from cornstalk by novel method coupling steam explosion and mechanical carding fractionation.

PubMed

Wang, Ning; Chen, Hong-Zhang

2013-07-01

In order to solve the inhomogeneity of cornstalk as fiber material to manufacture dissolving pulp, a novel method of steam explosion coupling mechanical carding was put forward to fractionate cornstalk long fiber for the production of cornstalk dissolving pulp. The fractionated long fiber had homogeneous structure and low hemicellulose and ash content. The fiber cell content was up to 85% in area, and the hemicellulose and ash content was 8.34% and 1.10% respectively. The α-cellulose content of cornstalk dissolving pulps was up to 93.10-97.10%, the viscosity was 14.37-23.96 mPas, and the yields of cornstalk dissolving pulps were from 10.11% to 12.44%. In addition, the fractionated short fiber was to be hydrolyzed by enzyme to build sugar platform. The constructed method of steam explosion coupling mechanical carding achieved the fractionation of cornstalk into long fiber and short fiber cleanly and effectively, and provided a new way for cornstalk integrated refinery. Copyright © 2013 Elsevier Ltd. All rights reserved.

Femtogram detection of explosive nitroaromatics: fluoranthene-based fluorescent chemosensors.

PubMed

Venkatramaiah, N; Kumar, Shiv; Patil, Satish

2012-11-12

Herein we report a novel fluoranthene-based fluorescent fluorophore 7,10-bis(4-bromophenyl)-8,9-bis[4-(hexyloxy)phenyl]fluoranthene (S(3)) and its remarkable properties in applications of explosive detection. The sensitivity towards the detection of nitroaromatics (NACs) was evaluated through fluorescence quenching in solution, vapor, and contact mode approaches. The contact mode approach using thin-layer silica chromatographic plates exhibited a femtogram (1.15 fg cm(-2)) detection limit for trinitrotoluene (TNT) and picric acid (PA), whereas the solution-phase quenching showed PA detection at the 2-20 ppb level. Fluorescence lifetime measurements revealed that the quenching is static in nature and the quenching process is fully reversible. Binding energies between model binding sites of the S(3) and analyte compounds reveal that analyte molecules enter into the cavity created by substituted phenyl rings of fluoranthene and are stabilized by strong intermolecular interactions with alkyl chains. It is anticipated that the sensor S(3) could be a promising material for the construction of portable optical devices for the detection of onsite explosive nitroaromatics. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Transient/structural analysis of a combustor under explosive loads

NASA Technical Reports Server (NTRS)

Gregory, Peyton B.; Holland, Anne D.

1992-01-01

The 8-Foot High Temperature Tunnel (HTT) at NASA Langley Research Center is a combustion-driven blow-down wind tunnel. A major potential failure mode that was considered during the combustor redesign was the possibility of a deflagration and/or detonation in the combustor. If a main burner flame-out were to occur, then unburned fuel gases could accumulate and, if reignited, an explosion could occur. An analysis has been performed to determine the safe operating limits of the combustor under transient explosive loads. The failure criteria was defined and the failure mechanisms were determined for both peak pressures and differential pressure loadings. An overview of the gas dynamics analysis was given. A finite element model was constructed to evaluate 13 transient load cases. The sensitivity of the structure to the frequency content of the transient loading was assessed. In addition, two closed form dynamic analyses were conducted to verify the finite element analysis. It was determined that the differential pressure load or thrust load was the critical load mechanism and that the nozzle is the weak link in the combustor system.

Device for Detection of Explosives, Nuclear and Other Hazardous Materials in Luggage and Cargo Containers

NASA Astrophysics Data System (ADS)

Kuznetsov, Andrey; Evsenin, Alexey; Gorshkov, Igor; Osetrov, Oleg; Vakhtin, Dmitry

2009-12-01

Device for detection of explosives, radioactive and heavily shielded nuclear materials in luggage and cargo containers based on Nanosecond Neutron Analysis/Associated Particles Technique (NNA/APT) is under construction. Detection module consists of a small neutron generator with built-in position-sensitive detector of associated alpha-particles, and several scintillator-based gamma-ray detectors. Explosives and other hazardous chemicals are detected by analyzing secondary high-energy gamma-rays from reactions of fast neutrons with materials inside a container. The same gamma-ray detectors are used to detect unshielded radioactive and nuclear materials. An array of several neutron detectors is used to detect fast neutrons from induced fission of nuclear materials. Coincidence and timing analysis allows one to discriminate between fission neutrons and scattered probing neutrons. Mathematical modeling by MCNP5 and MCNP-PoliMi codes was used to estimate the sensitivity of the device and its optimal configuration. Comparison of the features of three gamma detector types—based on BGO, NaI and LaBr3 crystals is presented.

Degassing vs. eruptive styles at Mt. Etna volcano (Sicily, Italy): Volatile stocking, gas fluxing, and the shift from low-energy to highly-explosive basaltic eruptions

NASA Astrophysics Data System (ADS)

Moretti, Roberto; Métrich, Nicole; Di Renzo, Valeria; Aiuppa, Alessandro; Allard, Patrick; Arienzo, Ilenia

2017-04-01

Basaltic magmas can transport and release large amounts of volatiles into the atmosphere, especially in subduction zones, where slab-derived fluids enrich the mantle wedge. Depending on magma volatile content, basaltic volcanoes thus display a wide spectrum of eruptive styles, from common Strombolian-type activity to Plinian events. Mt. Etna in Sicily, is a typical basaltic volcano where the volatile control on such a variable activity can be investigated. Based on a melt inclusion study in products from Strombolian or lava-fountain activity to Plinian eruptions, here we show that for the same initial volatile content, different eruptive styles reflect variable degassing paths throughout the composite Etnean plumbing system. The combined influence of i) crystallization, ii) deep degassing and iii) CO2 gas fluxing can explain the evolution of H2O, CO2, S and Cl in products from such a spectrum of activity. Deep crystallization produces the CO2-rich gas fluxing the upward magma portions, which will become buoyant and easily mobilized in small gas-rich batches stored within the plumbing system. When reaching gas dominated conditions (i.e., a gas/melt mass ratio of 0.3 and CO2,gas/H2Ogas molar ratio 5 ), these will erupt effusively or mildly explosively, whilst in case of the 122 BC Plinian eruption, open-system degassing conditions took place within the plumbing system, such that continuous CO2-fluxing determined gas accumulation on top of the magmatic system. The emission of such a cap in the early eruptive phase triggered the arrival of deep H2O-rich whose fast decompression and bubble nucleation lead to the highly explosive character, enhanced by abundant microlite crystallization and consequent increase of magma effective viscosity. This could explain why open system basaltic systems like Etna may experience highly explosive or even Plinian episodes during eruptions that start with effusive to mildly explosive phases. The proposed mechanism also determines a depression of chlorine contents in CO2-fluxed (and less explosive) magmas with respect to those feeding Plinian events like 122 BC one. The opposite is seen for sulfur: low to mild-explosive fluxed magmas are S-enriched, whereas the 122 BC Plinian products are relatively S-poor, likely because of early sulfide separation accompanying magma crystallization. The proposed mechanism involving CO2 separation and fluxing may suggest a subordinate role for variable mixing of different sources having different degrees of K-enrichment. However, such a mechanism requires further experimental studies about the effects on S and Cl dissolution and does not exclude self-mixing between degassed and undegassed batches within the Etna plumbing system. Finally, our findings may represent a new interpretative tool for the geochemical and petrological monitoring of plume gas discharges and melt inclusions, and allow tracking the switch from mild-explosive to highly explosive or even Plinian events at Etna.

Nanotwin Formation in High-Manganese Austenitic Steels Under Explosive Shock Loading

NASA Astrophysics Data System (ADS)

Canadinc, D.; Uzer, B.; Elmadagli, M.; Guner, F.

2018-04-01

The micro-deformation mechanisms active in a high-manganese austenitic steel were investigated upon explosive shock loading. Single system of nanotwins forming within primary twins were shown to govern the deformation despite the elevated temperatures attained during testing. The benefits of nanotwin formation for potential armor materials were demonstrated.

76 FR 9375 - Proposed Extension of Existing Information Collection; Sealing of Abandoned Areas

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-17

... prevent potentially explosive or toxic gases from migrating into the active working areas of underground... behind the seal must be monitored to prevent methane from reaching the explosive range. Miners rely on... used; Enhance the quality, utility, and clarity of the information to be collected; and Minimize the...

77 FR 67026 - Agency Information Collection Activities: Proposed Collection; Comments Requested: Report of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-08

... Lost ATF Form 5400.30, Intrastate Purchase of Explosives Coupon ACTION: 60-day notice. The Department... the following four points: --Evaluate whether the proposed collection of information is necessary for... or Lost ATF F 5400.30, Intrastate Purchase Explosives Coupon. (3) Agency form number, if any, and the...

78 FR 14120 - Agency Information Collection Activities: Proposed Collection; Comments Requested: Statement of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-04

...--Marking of Plastic Explosives for the Purpose of Detection ACTION: 60-Day notice. The Department of... currently approved collection. (2) Title of the Form/Collection: Statement of Process--Marking of Plastic... information will be used to ensure that plastic explosives contain a detection agent as required by law. (5...

Hydroacoustic Recordings of Explosion-Induced Tremor at NW Rota-1 Volcano, Marianas

NASA Astrophysics Data System (ADS)

Caplan-Auerbach, J.; Dziak, R. P.; Lau, T. A.

2013-12-01

Hydroacoustic data recorded during the long-term eruption of NW Rota-1 submarine volcano (Marianas) reveal a wide variety of explosion and tremor signals. Data from a moored hydrophone deployed near the summit of NW Rota-1 from February 2009 to April 2010 confirm that NW Rota-1 was nearly continuously active during this time. Explosion acoustic signals have a wide range of frequencies: some carry energy that is bandlimited between 5-25 Hz while others show broadband signal strength between 5-200 Hz (even higher frequencies may be attenuated by the hydrophone's anti-aliasing filter at 220 Hz). The signal is observed to switch rapidly between low frequency and broadband explosion types. In many cases the explosion signals repeat at a high rate, with recurrence intervals between 0.1-0.5 seconds. In such instances the explosions blend into tremor, exhibiting a large number of spectral harmonics that we attribute to the Dirac comb effect. The presence of these harmonics indicates that explosion recurrence intervals are highly regular, although subtle gliding within the harmonic frequencies suggests that there is some variability in the timing between explosions. This suggests a strongly repeatable explosion source. The frequency of explosions at NW Rota-1 is confirmed by ROV observations of eruption plume dynamics (Chadwick et al., 2008; Deardorff et al., 2008). We also observe a strong low-frequency (< 5 Hz) tremor signal that does not correlate with the explosion tremor, as well as strongly harmonic tremor that is not obviously composed of repeating explosions. These signals may reflect processes deeper within the conduit, yet still capable of coupling into the water column. Video footage collected during ROV dives in 2009 shows multiple instances in which the ground is observed to move, but these signals do not clearly correlate with hydroacoustic pulses. Deeper study into the source of these signals requires seismic instrumentation on and around NW Rota-1.

A decade of volcanic construction and destruction at the summit of NW Rota-1 seamount: 2004-2014

NASA Astrophysics Data System (ADS)

Schnur, Susan R.; Chadwick, William W.; Embley, Robert W.; Ferrini, Vicki L.; de Ronde, Cornel E. J.; Cashman, Katharine V.; Deardorff, Nicholas D.; Merle, Susan G.; Dziak, Robert P.; Haxel, Joe H.; Matsumoto, Haru

2017-03-01

Arc volcanoes are important to our understanding of submarine volcanism because at some sites frequent eruptions cause them to grow and collapse on human timescales. This makes it possible to document volcanic processes. Active submarine eruptions have been observed at the summit of NW Rota-1 in the Mariana Arc. We use remotely operated vehicle videography and repeat high-resolution bathymetric surveys to construct geologic maps of the summit of NW Rota-1 in 2009 and 2010 and relate them to the geologic evolution of the summit area over a 10 year period (2004-2014). We find that 2009 and 2010 were characterized by different eruptive styles, which affected the type and distribution of eruptive deposits at the summit. Year 2009 was characterized by ultraslow extrusion and autobrecciation of lava at a single eruptive vent, producing a large cone of blocky lava debris. In 2010, higher-energy explosive eruptions occurred at multiple closely spaced vents, producing a thin blanket of pebble-sized tephra overlying lava flow outcrops. A landslide that occurred between 2009 and 2010 had a major effect on lithofacies distribution by removing the debris cone and other unconsolidated deposits, revealing steep massive flow cliffs. This relatively rapid alternation between construction and destruction forms one end of a seamount growth and mass wasting spectrum. Intraplate seamounts, which tend to grow larger than arc volcanoes, experience collapse events that are orders of magnitude larger and much less frequent than those occurring at subduction zone settings. Our results highlight the interrelated cyclicity of eruptive activity and mass wasting at submarine arc volcanoes.

Sensitivity of OMI SO2 measurements to variable eruptive behaviour at Soufrière Hills Volcano, Montserrat

NASA Astrophysics Data System (ADS)

Hayer, C. S.; Wadge, G.; Edmonds, M.; Christopher, T.

2016-02-01

Since 2004, the satellite-borne Ozone Mapping Instrument (OMI) has observed sulphur dioxide (SO2) plumes during both quiescence and effusive eruptive activity at Soufrière Hills Volcano, Montserrat. On average, OMI detected a SO2 plume 4-6 times more frequently during effusive periods than during quiescence in the 2008-2010 period. The increased ability of OMI to detect SO2 during eruptive periods is mainly due to an increase in plume altitude rather than a higher SO2 emission rate. Three styles of eruptive activity cause thermal lofting of gases (Vulcanian explosions; pyroclastic flows; a hot lava dome) and the resultant plume altitudes are estimated from observations and models. Most lofting plumes from Soufrière Hills are derived from hot domes and pyroclastic flows. Although Vulcanian explosions produced the largest plumes, some produced only negligible SO2 signals detected by OMI. OMI is most valuable for monitoring purposes at this volcano during periods of lava dome growth and during explosive activity.

Seismic Imaging of the Source Physics Experiment Site with the Large-N Seismic Array

NASA Astrophysics Data System (ADS)

Chen, T.; Snelson, C. M.; Mellors, R. J.

2017-12-01

The Source Physics Experiment (SPE) consists of a series of chemical explosions at the Nevada National Security Site. The goal of SPE is to understand seismic wave generation and propagation from these explosions. To achieve this goal, we need an accurate geophysical model of the SPE site. A Large-N seismic array that was deployed at the SPE site during one of the chemical explosions (SPE-5) helps us construct high-resolution local geophysical model. The Large-N seismic array consists of 996 geophones, and covers an area of approximately 2 × 2.5 km. The array is located in the northern end of the Yucca Flat basin, at a transition from Climax Stock (granite) to Yucca Flat (alluvium). In addition to the SPE-5 explosion, the Large-N array also recorded 53 weight drops. Using the Large-N seismic array recordings, we perform body wave and surface wave velocity analysis, and obtain 3D seismic imaging of the SPE site for the top crust of approximately 1 km. The imaging results show clear variation of geophysical parameter with local geological structures, including heterogeneous weathering layer and various rock types. The results of this work are being incorporated in the larger 3D modeling effort of the SPE program to validate the predictive models developed for the site.

Novel high-fidelity realistic explosion damage simulation for urban environments

NASA Astrophysics Data System (ADS)

Liu, Xiaoqing; Yadegar, Jacob; Zhu, Youding; Raju, Chaitanya; Bhagavathula, Jaya

2010-04-01

Realistic building damage simulation has a significant impact in modern modeling and simulation systems especially in diverse panoply of military and civil applications where these simulation systems are widely used for personnel training, critical mission planning, disaster management, etc. Realistic building damage simulation should incorporate accurate physics-based explosion models, rubble generation, rubble flyout, and interactions between flying rubble and their surrounding entities. However, none of the existing building damage simulation systems sufficiently faithfully realize the criteria of realism required for effective military applications. In this paper, we present a novel physics-based high-fidelity and runtime efficient explosion simulation system to realistically simulate destruction to buildings. In the proposed system, a family of novel blast models is applied to accurately and realistically simulate explosions based on static and/or dynamic detonation conditions. The system also takes account of rubble pile formation and applies a generic and scalable multi-component based object representation to describe scene entities and highly scalable agent-subsumption architecture and scheduler to schedule clusters of sequential and parallel events. The proposed system utilizes a highly efficient and scalable tetrahedral decomposition approach to realistically simulate rubble formation. Experimental results demonstrate that the proposed system has the capability to realistically simulate rubble generation, rubble flyout and their primary and secondary impacts on surrounding objects including buildings, constructions, vehicles and pedestrians in clusters of sequential and parallel damage events.

Pigeonholing pyroclasts: Insights from the 19 March 2008 explosive eruption of Kīlauea volcano

USGS Publications Warehouse

Houghton, Bruce F.; Swanson, D.A.; Carey, R.J.; Rausch, J.; Sutton, A.J.

2011-01-01

We think, conventionally, of volcanic explosive eruptions as being triggered in one of two ways: by release and expansion of volatiles dissolved in the ejected magma (magmatic explosions) or by transfer of heat from magma into an external source of water (phreatic or phreatomagmatic explosions). We document here an event where neither magma nor an external water source was involved in explosive activity at K??lauea. Instead, the eruption was powered by the expansion of decoupled magmatic volatiles released from deeper magma, which was not ejected by the eruption, and the trigger was a collapse of near-surface wall rocks that then momentarily blocked that volatile flux. Mapping of the advected fall deposit a day after this eruption has highlighted the difficulty of constraining deposit edges from unobserved or prehistoric eruptions of all magnitudes. Our results suggest that the dispersal area of advected fall deposits could be miscalculated by up to 30% of the total, raising issues for accurate hazard zoning and assessment. Eruptions of this type challenge existing classification schemes for pyroclastic deposits and explosive eruptions and, in the past, have probably been interpreted as phreatic explosions, where the eruptive mechanism has been assumed to involve flashing of groundwater to steam. ?? 2011 Geological Society of America.

Task Order 7. Use of activated carbon for treatment of explosives-contaminated groundwater at the Milan Army Ammunition Plant (MAAP). Final report, Apr 89-May 90

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dennis, R.M.; Wujcik, W.J.; Lowe, W.L.

1990-05-01

The primary objective of this task was to determine the feasibility of using GAC to treat ground water contaminated by explosives at the Milan Army Ammunition Plant (MAAP) in Milan, Tennessee. Laboratory GAC isotherm studies were conducted and two carbons, Atochem, Inc. GAC 830 and Calgon Filtrasorb 300, were selected for further testing in continuous flow GAC columns. Three pilot scale continuous flow GAC column tests were performed at MAAP using the two carbons selected from the laboratory GAC isotherm studies. The results from the laboratory and pilot studies are presented in this report. They show that concurrent removal ofmore » explosives such as TNT, RDX, HMX, Tetryl, and nitrobenzenes from ground water using continuous flow granular activated carbon is feasible.« less

Eruptive history of the Dieng Mountains region, central Java, and potential hazards from future eruptions

USGS Publications Warehouse

Miller, C. Dan; Sushyar, R.; ,; Hamidi, S.

1983-01-01

The Dieng Mountains region consists of a complex of late Quaternary to recent volcanic stratocones, parasitic vents, and explosion craters. Six age groups of volcanic centers, eruptive products, and explosion craters are recognized in the region based on their morphology, degree of dissection, stratigraphic relationships, and degree of weathering. These features range in age from tens of thousands of years to events that have occurred this century. No magmatic eruptions have occurred in the Dieng Mountains region for at least several thousand years; volcanic activity during this time interval has consisted of phreatic eruptions and non-explosive hydrothermal activity. If future volcanic events are similar to those of the last few thousand years, they will consist of phreatic eruptions, associated small hot mudflows, emission of suffocating gases, and hydrothermal activity. Future phreatic eruptions may follow, or accompany, periods of increased earthquake activity; the epicenters for the seismicity may suggest where eruptive activity will occur. Under such circumstances, the populace within several kilometers of a potential eruption site should be warned of a possible eruption, given instructions about what to do in the event of an eruption, or temporarily evacuated to a safer location.

Experiments in progress: The geography of science in the Atomic Energy Commission's peaceful uses of nuclear explosives program, 1956-1973

NASA Astrophysics Data System (ADS)

Kirsch, Scott Lawrence

From 1957 to 1973, the United States Atomic Energy Commission (AEC) actively pursued the "peaceful uses of nuclear explosives" through Project Plowshare. Nuclear excavation, the detonation of shallowly buried hydrogen bombs for massive earthmoving projects like harbors and canals, was considered the most promising of the Plowshare applications, and for a time, the most economically and technically "feasible." With a basis in and contributing to theory in critical human geography and science studies, the purpose of this dissertation is to examine the collisions of science, ideology, and politics which kept Plowshare designs alive--but only as "experiments in progress." That is, this research asks how the experimental program persisted in places like the national weapons laboratory in Livermore, California, and how its ideas were tested at the nuclear test site in Nevada, yet Plowshare was kept out of those spaces beyond AEC control. Primary research focuses on AEC-related archival materials collected from the Department of Energy Coordination and Information Center, Las Vegas, Nevada, and from the Lawrence Livermore National Laboratory, as well as the public discourse through which support for and opposition to Plowshare projects was voiced. Through critical analysis of Plowshare's grandiose "geographical engineering" schemes, I thus examine the complex relations between the social construction of science and technology, on one hand, and the social production of space, on the other.

Discovery of a Powerful, Transient, Explosive Thermal Event at Marduk Fluctus, Io, in Galileo NIMS Data

NASA Astrophysics Data System (ADS)

Davies, A. G.; Davies, R. L.; Veeder, G. J.; de Kleer, K.; de Pater, I.; Matson, D. L.; Johnson, T. V.; Wilson, L.

2018-04-01

Analysis of Galileo Near-Infrared Mapping Spectrometer observations of Marduk Fluctus, a volcano on the Jovian moon Io, reveals a style of volcanic activity not previously seen there—a powerful thermal event lasting only a few minutes in 1996. The thermal emission rapidly fades, suggesting extremely rapid cooling of small clasts. The duration and evolution of the explosive eruption are akin to what might be expected from a strombolian or vulcanian explosion. The presence of such events provides an additional volcanic process that can be imaged by future missions with the intent of determining lava composition from eruption temperature, an important constraint on the internal composition of Io. These data promise to be of particular use in understanding the mechanics of explosive volcanic processes on Io.

Late-time X-rays to map the Zoo of Engine-driven Stellar Explosions

NASA Astrophysics Data System (ADS)

Margutti, Raffaella

2017-09-01

We propose a continuation of our effort to monitor nearby long GRBs (z <=0.3) with Chandra. Our synergistic multi-wavelength program (radio, optical, Swift and proposed Chandra) is designed to extract the true energy of these explosions and to reveal the activity of their central engines. This effort allows us to: (i) investigate whether sub-energetic GRBs share the same explosion mechanisms and central engines as ordinary GRBs; (ii) investigate what essential physical property enables only a small fraction of supernovae to harbor a relativistic outflow; (iii) understand if jet-driven explosions are common in all SNe. These objectives are only possible by expanding the current small sample of well-observed local GRBs and by drawing comparisons with cosmological GRBs and common SNe.

Thermal stability and kinetics of decomposition of ammonium nitrate in the presence of pyrite.

PubMed

Gunawan, Richard; Zhang, Dongke

2009-06-15

The interaction between ammonium nitrate based industrial explosives and pyrite-rich minerals in mining operations can lead to the occurrence of spontaneous explosion of the explosives. In an effort to provide a scientific basis for safe applications of industrial explosives in reactive mining grounds containing pyrite, ammonium nitrate decomposition, with and without the presence of pyrite, was studied using a simultaneous Differential Scanning Calorimetry and Thermogravimetric Analyser (DSC-TGA) and a gas-sealed isothermal reactor, respectively. The activation energy and the pre-exponential factor of ammonium nitrate decomposition were determined to be 102.6 kJ mol(-1) and 4.55 x 10(7)s(-1) without the presence of pyrite and 101.8 kJ mol(-1) and 2.57 x 10(9)s(-1) with the presence of pyrite. The kinetics of ammonium nitrate decomposition was then used to calculate the critical temperatures for ammonium nitrate decomposition with and without the presence of pyrite, based on the Frank-Kamenetskii model of thermal explosion. It was shown that the presence of pyrite reduces the temperature for, and accelerates the rate of, decomposition of ammonium nitrate. It was further shown that pyrite can significantly reduce the critical temperature of ammonium nitrate decomposition, causing undesired premature detonation of the explosives. The critical temperature also decreases with increasing diameter of the blast holes charged with the explosive. The concept of using the critical temperature as indication of the thermal stability of the explosives to evaluate the risk of spontaneous explosion was verified in the gas-sealed isothermal reactor experiments.

Inductive Measurement of Plasma Jet Electrical Conductivity

NASA Technical Reports Server (NTRS)

Turner, Matthew W.; Hawk, Clark W.; Litchford, Ron J.

2005-01-01

An inductive probing scheme, originally developed for shock tube studies, has been adapted to measure explosive plasma jet conductivities. In this method, the perturbation of an applied magnetic field by a plasma jet induces a voltage in a search coil, which, in turn, can be used to infer electrical conductivity through the inversion of a Fredholm integral equation of the first kind. A 1-inch diameter probe was designed and constructed, and calibration was accomplished by firing an aluminum slug through the probe using a light-gas gun. Exploratory laboratory experiments were carried out using plasma jets expelled from 15-gram high explosive shaped charges. Measured conductivities were in the range of 3 kS/m for unseeded octol charges and 20 kS/m for seeded octol charges containing 2% potassium carbonate by mass.

Graphene oxide-based optical biosensor functionalized with peptides for explosive detection.

PubMed

Zhang, Qian; Zhang, Diming; Lu, Yanli; Yao, Yao; Li, Shuang; Liu, Qingjun

2015-06-15

A label-free optical biosensor was constructed with biofunctionalized graphene oxide (GO) for specific detection of 2,4,6-trinitrotoluene (TNT). By chemically binding TNT-specific peptides with GO, the biosensor gained unique optoelectronic properties and high biological sensitivity, with transducing bimolecular bonding into optical signals. Through UV absorption detection, increasing absorbance responses could be observed in presence of TNT at different concentrations, as low as 4.40×10(-9) mM, and showed dose-dependence and stable behavior. Specific responses of the biosensor were verified with the corporation of 2,6-dinitrotoluene (DNT), which had similar molecular structure to TNT. Thus, with high sensitivity and selectivity, the biosensor provided a convenient approach for detection of explosives as miniaturizing and integrating devices. Copyright © 2015 Elsevier B.V. All rights reserved.

8. BUILDING NO. 611. INTERIOR OF ARMOR PLATELINED TESTING CHAMBER. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. BUILDING NO. 611. INTERIOR OF ARMOR PLATE-LINED TESTING CHAMBER. 1/2' THICK ARMOR PLATING BOLTED TO WALLS, FLOOR AND CEILING. WALLS CONSTRUCTED OF 24' THICK REINFORCED CONCRETE. VENTS IN CEILING EXHAUST SMOKE FROM EXPLOSIONS. SMALLEST WHEELED VEHICLES HOLD DUDS. - Picatinny Arsenal, 600 Area, Test Areas District, State Route 15 near I-80, Dover, Morris County, NJ

Beam Dynamics for ARIA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ekdahl, Carl August Jr.

2014-10-14

Beam dynamics issues are assessed for a new linear induction electron accelerator being designed for flash radiography of large explosively driven hydrodynamic experiments. Special attention is paid to equilibrium beam transport, possible emittance growth, and beam stability. It is concluded that a radiographic quality beam will be produced possible if engineering standards and construction details are equivalent to those on the present radiography accelerators at Los Alamos.

Efficient search, mapping, and optimization of multi-protein genetic systems in diverse bacteria

PubMed Central

Farasat, Iman; Kushwaha, Manish; Collens, Jason; Easterbrook, Michael; Guido, Matthew; Salis, Howard M

2014-01-01

Developing predictive models of multi-protein genetic systems to understand and optimize their behavior remains a combinatorial challenge, particularly when measurement throughput is limited. We developed a computational approach to build predictive models and identify optimal sequences and expression levels, while circumventing combinatorial explosion. Maximally informative genetic system variants were first designed by the RBS Library Calculator, an algorithm to design sequences for efficiently searching a multi-protein expression space across a > 10,000-fold range with tailored search parameters and well-predicted translation rates. We validated the algorithm's predictions by characterizing 646 genetic system variants, encoded in plasmids and genomes, expressed in six gram-positive and gram-negative bacterial hosts. We then combined the search algorithm with system-level kinetic modeling, requiring the construction and characterization of 73 variants to build a sequence-expression-activity map (SEAMAP) for a biosynthesis pathway. Using model predictions, we designed and characterized 47 additional pathway variants to navigate its activity space, find optimal expression regions with desired activity response curves, and relieve rate-limiting steps in metabolism. Creating sequence-expression-activity maps accelerates the optimization of many protein systems and allows previous measurements to quantitatively inform future designs. PMID:24952589

The Gaseous Explosive Reaction : The Effect of Inert Gases

NASA Technical Reports Server (NTRS)

Stevens, F W

1928-01-01

Attention is called in this report to previous investigations of gaseous explosive reactions carried out under constant volume conditions, where the effect of inert gases on the thermodynamic equilibrium was determined. The advantage of constant pressure methods over those of constant volume as applied to studies of the gaseous explosive reaction is pointed out and the possibility of realizing for this purpose a constant pressure bomb mentioned. The application of constant pressure methods to the study of gaseous explosive reactions, made possible by the use of a constant pressure bomb, led to the discovery of an important kinetic relation connecting the rate of propagation of the zone of explosive reaction within the active gases, with the initial concentrations of those gases: s = K(sub 1)(A)(sup n1)(B)(sup n2)(C)(sup n3)------. By a method analogous to that followed in determining the effect of inert gases on the equilibrium constant K, the present paper records an attempt to determine their kinetic effect upon the expression given above.

Petrologic constraints on the decompression history of magma prior to Vulcanian explosions at the Soufrière Hills volcano, Montserrat

NASA Astrophysics Data System (ADS)

Clarke, A. B.; Stephens, S.; Teasdale, R.; Sparks, R. S. J.; Diller, K.

2007-04-01

A series of 88 Vulcanian explosions occurred at the Soufrière Hills volcano, Montserrat, between August and October, 1997. Conduit conditions conducive to creating these and other Vulcanian explosions were explored via analysis of eruptive products and one-dimensional numerical modeling of magma ascent through a cylindrical conduit. The number densities and textures of plagioclase microlites were documented for twenty-three samples from the events. The natural samples all show very high number densities of microlites, and > 50% by number of microlites have areas < 20 μm 2. Pre-explosion conduit conditions and decompression history have been inferred from these data by comparison with experimental decompressions of similar groundmass compositions. Our comparisons suggest quench pressures < 30 MPa (origin depths < 2 km) and multiple rapid decompressions of > 13.75 MPa each during ascent from chamber to surface. Values are consistent with field studies of the same events and statistical analysis of explosion time-series data. The microlite volume number density trend with depth reveals an apparent transition from growth-dominated crystallization to nucleation-dominated crystallization at pressures of ˜ 7 MPa and lower. A concurrent sharp increase in bulk density marks the onset of significant open-system degassing, apparently due to a large increase in system permeability above ˜ 70% vesicularity. This open-system degassing results in a dense plug which eventually seals the conduit and forms conditions favorable to Vulcanian explosions. The corresponding inferred depth of overpressure at 250-700 m, near the base of the dense plug, is consistent with depth to center of pressure estimated from deformation measurements. Here we also illustrate that one-dimensional models representing ascent of a degassing, crystal-rich magma are broadly consistent with conduit profiles constructed via our petrologic analysis. The comparison between models and petrologic data suggests that the dense conduit plug forms as a result of high overpressure and open-system degassing through conduit walls.

The Young Massive Stellar Cluster Sandage-96 after the Explosion of SN 2004DJ in NGC 2403

NASA Technical Reports Server (NTRS)

Vinko, J.; Sarneczky, K.; Balog, Z.; Immler, S.; Sugerman, B.; Brown, P. J.; Misselt, K.; Szabo, Gy. M.; Klagyivik, P.; Kun, M.;

The Main Sequence of Explosive Solar Active Regions: Comparison of Emerging and Mature Active Regions

NASA Technical Reports Server (NTRS)

Falconer, David; Moore, Ron

2011-01-01

For mature active regions, an active region s magnetic flux content determines the maximum free energy the active region can have. Most Large flares and CMEs occur in active regions that are near their free-energy limit. Active-region flare power radiated in the GOES 1-8 band increases steeply as the free-energy limit is approached. We infer that the free-energy limit is set by the rate of release of an active region s free magnetic energy by flares, CMEs and coronal heating balancing the maximum rate the Sun can put free energy into the active region s magnetic field. This balance of maximum power results in explosive active regions residing in a "mainsequence" in active-region (flux content, free energy content) phase space, which sequence is analogous to the main sequence of hydrogen-burning stars in (mass, luminosity) phase space.

Dynamics of an open basaltic magma system: The 2008 activity of the Halema‘uma‘u Overlook vent, Kīlauea Caldera

USGS Publications Warehouse

Eychenne, Julia; Houghton, Bruce F.; Swanson, Don; Carey, Rebecca; Swavely, Lauren

2015-01-01

On March 19, 2008 a small explosive event accompanied the opening of a 35-m-wide vent (Overlook vent) on the southeast wall of Halema‘uma‘u Crater in Kīlauea Caldera, initiating an eruptive period that extends to the time of writing. The peak of activity, in 2008, consisted of alternating background open-system outgassing and spattering punctuated by sudden, short-lived weak explosions, triggered by collapses of the walls of the vent and conduit. Near-daily sampling of the tephra from this open system, along with exceptionally detailed observations, allow us to study the dynamics of the activity during two eruptive sequences in late 2008. Each sequence includes background activity preceding and following one or more explosions in September and October 2008 respectively. Componentry analyses were performed for daily samples to characterise the diversity of the ejecta. Nine categories of pyroclasts were identified in all the samples, including wall-rock fragments. The six categories of juvenile clasts can be grouped in three classes based on vesicularity: (1) poorly, (2) uniformly highly to extremely, and (3) heterogeneously highly vesicular. The wall-rock and juvenile clasts show dissimilar grainsize distributions, reflecting different fragmentation mechanisms. The wall-rock particles formed by failure of the vent and conduit walls above the magma free surface and were then passively entrained in the eruptive plume. The juvenile componentry reveals consistent contrasts in degassing and fragmentation processes before, during and after the explosive events. We infer a crude ‘layering’ developed in the shallow melt, in terms of both rheology and bubble and volatile contents, beneath a convecting free surface during background activity. A tens-of-centimetres thick viscoelastic surface layer was effectively outgassed and relatively cool, while at depths of less than 100 m, the melt remained slightly supersaturated in volatiles and actively vesiculating. Decoupled metre-sized bubbles rising through the column burst through the free surface frequently, ejecting fragments of the outgassed upper layer. When the surface was abruptly perturbed by the rock-falls, existing mm-sized bubbles expanded, leading to the acceleration of adjacent melt upward and consecutive explosions, while renewed nucleation created a minor population of 10-micron-sized bubbles. After each explosive event in September–October 2008, this layering was re-established but with decreasing vigour, suggesting that the magma batch as a whole was becoming progressively depleted in dissolved volatiles.

Energetic Residues and Crater Geometries from the Firing of 120-mm High-Explosive Mortar Projectiles into Eagle River Flats, June 2007

DTIC Science & Technology

2008-07-01

samples. ERDC/CRREL TR-08-10 15 c. US DH-48 isokinetic sampler. Figure 7 (cont’d). The second activity was the collection of soil at the...3 0.28 Mc1/3 0.3 Mc1/3 Ra Apparent radius of the crater in meters Mc Mass of the explosive charge in kilograms Da Apparent depth of the crater in... meters The apparent depth and radius of a crater will increase with the depth of explosive charge below the surface down to a maximum depth called

Modeling Explosion Induced Aftershocks

NASA Astrophysics Data System (ADS)

Kroll, K.; Ford, S. R.; Pitarka, A.; Walter, W. R.; Richards-Dinger, K. B.

2017-12-01

Many traditional earthquake-explosion discrimination tools are based on properties of the seismic waveform or their spectral components. Common discrimination methods include estimates of body wave amplitude ratios, surface wave magnitude scaling, moment tensor characteristics, and depth. Such methods are limited by station coverage and noise. Ford and Walter (2010) proposed an alternate discrimination method based on using properties of aftershock sequences as a means of earthquakeexplosion differentiation. Previous studies have shown that explosion sources produce fewer aftershocks that are generally smaller in magnitude compared to aftershocks of similarly sized earthquake sources (Jarpe et al., 1994, Ford and Walter, 2010). It has also been suggested that the explosion-induced aftershocks have smaller Gutenberg- Richter b-values (Ryall and Savage, 1969) and that their rates decay faster than a typical Omori-like sequence (Gross, 1996). To discern whether these observations are generally true of explosions or are related to specific site conditions (e.g. explosion proximity to active faults, tectonic setting, crustal stress magnitudes) would require a thorough global analysis. Such a study, however, is hindered both by lack of evenly distributed explosion-sources and the availability of global seismicity data. Here, we employ two methods to test the efficacy of explosions at triggering aftershocks under a variety of physical conditions. First, we use the earthquake rate equations from Dieterich (1994) to compute the rate of aftershocks related to an explosion source assuming a simple spring-slider model. We compare seismicity rates computed with these analytical solutions to those produced by the 3D, multi-cycle earthquake simulator, RSQSim. We explore the relationship between geological conditions and the characteristics of the resulting explosion-induced aftershock sequence. We also test hypothesis that aftershock generation is dependent upon the frequency content of the passing dynamic seismic waves as suggested by Parsons and Velasco (2009). Lastly, we compare all results of explosion-induced aftershocks with aftershocks generated by similarly sized earthquake sources. Prepared by LLNL under Contract DE-AC52-07NA27344.

Small explosive volcanic plume dynamics: insights from feature tracking velocimetry at Santiaguito lava dome

NASA Astrophysics Data System (ADS)

Benage, M. C.; Andrews, B. J.

2016-12-01

Volcanic explosions eject turbulent, transient jets of hot volcanic gas and particles into the atmosphere. Though the jet of hot material is initially negatively buoyant, the jet can become buoyant through entrainment and subsequent thermal expansion of entrained air that allows the eruptive plume to rise several kilometers. Although basic plume structure is qualitatively well known, the velocity field and dynamic structure of volcanic plumes are not well quantified. An accurate and quantitative description of volcanic plumes is essential for hazard assessments, such as if the eruption will form a buoyant plume that will affect aviation or produce dangerous pyroclastic density currents. Santa Maria volcano, in Guatemala, provides the rare opportunity to safely capture video of Santiaguito lava dome explosions and small eruptive plumes. In January 2016, two small explosions (< 2 km) that lasted several minutes and with little cloud obstruction were recorded for image analysis. The volcanic plume structure is analyzed through sequential image frames from the video where specific features are tracked using a feature tracking velocimetry (FTV) algorithm. The FTV algorithm quantifies the 2D apparent velocity fields along the surface of the plume throughout the duration of the explosion. Image analysis of small volcanic explosions allows us to examine the maximum apparent velocities at two heights above the dome surface, 0-25 meters, where the explosions first appear, and 100-125 meters. Explosions begin with maximum apparent velocities of <15 m/s. We find at heights near the dome surface and 10 seconds after explosion initiation, the maximum apparent velocities transition to sustained velocities of 5-15 m/s. At heights 100-125 meters above the dome surface, the apparent velocities transition to sustained velocities of 5-15 m/s after 25 seconds. Throughout the explosion, transient velocity maximums can exceed 40 m/s at both heights. Here, we provide novel quantification and description of turbulent surface velocity fields of explosive volcanic eruptions at active lava domes.

Influence of Axisymmetrically Deformed Explosions in Type II Supernovae on the Reproduction of the Solar System Abundances

NASA Astrophysics Data System (ADS)

Nagataki, Shigehiro

1999-01-01

We have tried to reproduce the solar system abundances using the nucleosynthesis products of Type Ia and Type II supernovae. In particular, we examined the effects of axisymmetrically deformed explosions in Type II supernovae. 44Ca and 47,48Ti are enhanced considerably in axisymmetrically deformed explosion models because of the active alpha-rich freezeout. The enhancement of nuclei around A=45 is a welcome result since it solves the problem of the nuclei shortage. Moreover, 59Co, 63,65Cu, and 66Zn are enhanced enough to reproduce the solar system abundances. The enhancement of Cu and Zn means the possibility that these nuclei, which have been said to be produced by the slow process, can be synthesized fairly well during the explosive nucleosynthesis. To discuss their origin quantitatively, the position of the mass cut is a very important parameter that is very difficult to determine numerically at present. We also stress that an axisymmetrically deformed explosion of Type II supernovae of the degree that is considered in this analysis is not excluded by the results of calculations of explosive nucleosynthesis, that is, the nucleosynthesis products are not extremely disturbed and the solar system abundances can be reproduced fairly well by the axisymmetrically deformed explosion models. This conclusion will be good for the theory of core collapse including the rotation of an iron core, magnetic field, and axisymmetrically modified neutrino radiation from a rotating protoneutron star, which possibly can cause an axisymmetrically deformed explosion.

Optimization of biological and instrumental detection of explosives and ignitable liquid residues including canines, SPME/ITMS and GC/MSn

NASA Astrophysics Data System (ADS)

Furton, Kenneth G.; Harper, Ross J.; Perr, Jeannette M.; Almirall, Jose R.

2003-09-01

A comprehensive study and comparison is underway using biological detectors and instrumental methods for the rapid detection of ignitable liquid residues (ILR) and high explosives. Headspace solid phase microextraction (SPME) has been demonstrated to be an effective sampling method helping to identify active odor signature chemicals used by detector dogs to locate forensic specimens as well as a rapid pre-concentration technique prior to instrumental detection. Common ignitable liquids and common military and industrial explosives have been studied including trinitrotoluene, tetryl, RDX, HMX, EGDN, PETN and nitroglycerine. This study focuses on identifying volatile odor signature chemicals present, which can be used to enhance the level and reliability of detection of ILR and explosives by canines and instrumental methods. While most instrumental methods currently in use focus on particles and on parent organic compounds, which are often involatile, characteristic volatile organics are generally also present and can be exploited to enhance detection particularly for well-concealed devices. Specific examples include the volatile odor chemicals 2-ethyl-1-hexanol and cyclohexanone, which are readily available in the headspace of the high explosive composition C-4; whereas, the active chemical cyclo-1,3,5-trimethylene-2,4,6-trinitramine (RDX) is not. The analysis and identification of these headspace 'fingerprint' organics is followed by double-blind dog trials of the individual components using certified teams in an attempt to isolate and understand the target compounds to which dogs are sensitive. Studies to compare commonly used training aids with the actual target explosive have also been undertaken to determine their suitability and effectiveness. The optimization of solid phase microextraction (SPME) combined with ion trap mobility spectrometry (ITMS) and gas chromatography/mass spectrometry/mass spectrometry (GC/MSn) is detailed including interface development and comparisons of limits of detection. These instrumental methods are being optimized in order to detect the same target odor chemicals used by detector dogs to reliably locate explosives and ignitable liquids.

Lattice Boltzmann modeling to explain volcano acoustic source.

PubMed

Brogi, Federico; Ripepe, Maurizio; Bonadonna, Costanza

2018-06-22

Acoustic pressure is largely used to monitor explosive activity at volcanoes and has become one of the most promising technique to monitor volcanoes also at large scale. However, no clear relation between the fluid dynamics of explosive eruptions and the associated acoustic signals has yet been defined. Linear acoustic has been applied to derive source parameters in the case of strong explosive eruptions which are well-known to be driven by large overpressure of the magmatic fluids. Asymmetric acoustic waveforms are generally considered as the evidence for supersonic explosive dynamics also for small explosive regimes. We have used Lattice-Boltzmann modeling of the eruptive fluid dynamics to analyse the acoustic wavefield produced by different flow regimes. We demonstrate that acoustic waveform well reproduces the flow dynamics of a subsonic fluid injection related to discrete explosive events. Different volumetric flow rate, at low-Mach regimes, can explain both the observed symmetric and asymmetric waveform. Hence, asymmetric waveforms are not necessarily related to the shock/supersonic fluid dynamics of the source. As a result, we highlight an ambiguity in the general interpretation of volcano acoustic signals for the retrieval of key eruption source parameters, necessary for a reliable volcanic hazard assessment.

Identifying a combined construct of grief and explosive anger as a response to injustice amongst survivors of mass conflict: A latent class analysis of data from Timor-Leste.

PubMed

Rees, Susan J; Tay, Alvin Kuowei; Savio, Elisa; Maria Da Costa, Zelia; Silove, Derrick

2017-01-01

Previous studies have identified high rates of explosive anger amongst post-conflict populations including Timor-Leste. We sought to test whether explosive anger was integrally associated with symptoms of grief amongst the Timorese, a society that has experienced extensive conflict-related losses. In 2010 and 2011 we recruited adults (n = 2964), 18-years and older, living in an urban and a rural village in Timor-Leste. We applied latent class analysis to identify subpopulations based on symptoms of explosive anger and grief. The best fitting model comprised three classes: grief (24%), grief-anger (25%), and a low symptom group (51%). There were more women and urban dwellers in the grief and grief-anger classes compared to the reference class. Persons in the grief and grief-anger classes experienced higher rates of witnessing murder and atrocities and traumatic losses, ongoing poverty, and preoccupations with injustice for the two historical periods of conflict (the Indonesian occupation and the later internal conflict). Compared to the reference class, only the grief-anger class reported greater exposure to extreme deprivations during the conflict, ongoing family conflict, and preoccupations with injustice for contemporary times; and compared to the grief class, greater exposure to traumatic losses, poverty, family conflict and preoccupations with injustice for both the internal conflict and contemporary times. A substantial number of adults in this post-conflict country experienced a combined constellation of grief and explosive anger associated with extensive traumatic losses, deprivations, and preoccupations with injustice. Importantly, grief-anger may be linked to family conflict in this post-conflict environment.

Supernova 1987A: The Supernova of a Lifetime

NASA Astrophysics Data System (ADS)

Kirshner, Robert

2017-01-01

Supernova 1987A, the brightest supernova since Kepler's in 1604, was detected 30 years ago at a distance of 160 000 light years in the Large Magellanic Cloud, a satellite galaxy of the Milky Way. Visible with the naked eye and detected with the full range of technology constructed since Kepler's time, SN 1987A has continued to be a rich source of empirical information to help understand supernova explosions and their evolution into supernova remnants. While the light output has faded by a factor of 10 000 000 over those 30 years, instrumentation, like the Hubble Space Telescope, the Chandra X-ray Observatory, and the Atacama Large Millimeter Array has continued to improve so that this supernova continues to be visible in X-rays, ultraviolet light, visible light, infrared light and in radio emission. In this review, I will sketch what has been learned from these observations about the pre-supernova star and its final stages of evolution, the explosion physics, the energy sources for emission, and the shock physics as the expanding debris encounters the circumstellar ring that was created about 20 000 years before the explosion. Today, SN 1987A is making the transition to a supernova remnant- the energetics are no longer dominated by the radioactive elements produced in the explosion, but by the interaction of the expanding debris with the surrounding gas. While we are confident that the supernova explosion had its origin in gravitational collapse, careful searches for a compact object at the center of the remnant place upper limits of a few solar luminosities on that relic. Support for HST GO programs 13401 and 13405 was provided by NASA through grants from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

Identifying a combined construct of grief and explosive anger as a response to injustice amongst survivors of mass conflict: A latent class analysis of data from Timor-Leste

PubMed Central

Rees, Susan J.; Tay, Alvin Kuowei; Savio, Elisa; Maria Da Costa, Zelia; Silove, Derrick

2017-01-01

Previous studies have identified high rates of explosive anger amongst post-conflict populations including Timor-Leste. We sought to test whether explosive anger was integrally associated with symptoms of grief amongst the Timorese, a society that has experienced extensive conflict-related losses. In 2010 and 2011 we recruited adults (n = 2964), 18-years and older, living in an urban and a rural village in Timor-Leste. We applied latent class analysis to identify subpopulations based on symptoms of explosive anger and grief. The best fitting model comprised three classes: grief (24%), grief-anger (25%), and a low symptom group (51%). There were more women and urban dwellers in the grief and grief-anger classes compared to the reference class. Persons in the grief and grief-anger classes experienced higher rates of witnessing murder and atrocities and traumatic losses, ongoing poverty, and preoccupations with injustice for the two historical periods of conflict (the Indonesian occupation and the later internal conflict). Compared to the reference class, only the grief-anger class reported greater exposure to extreme deprivations during the conflict, ongoing family conflict, and preoccupations with injustice for contemporary times; and compared to the grief class, greater exposure to traumatic losses, poverty, family conflict and preoccupations with injustice for both the internal conflict and contemporary times. A substantial number of adults in this post-conflict country experienced a combined constellation of grief and explosive anger associated with extensive traumatic losses, deprivations, and preoccupations with injustice. Importantly, grief-anger may be linked to family conflict in this post-conflict environment. PMID:28430793

Radionuclide observables for the Platte underground nuclear explosive test on 14 April 1962.

PubMed

Burnett, Jonathan L; Milbrath, Brian D

2016-11-01

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

Performance of an improved thermal neutron activation detector for buried bulk explosives

NASA Astrophysics Data System (ADS)

McFee, J. E.; Faust, A. A.; Andrews, H. R.; Clifford, E. T. H.; Mosquera, C. M.

2013-06-01

First generation thermal neutron activation (TNA) sensors, employing an isotopic source and NaI(Tl) gamma ray detectors, were deployed by Canadian Forces in 2002 as confirmation sensors on multi-sensor landmine detection systems. The second generation TNA detector is being developed with a number of improvements aimed at increasing sensitivity and facilitating ease of operation. Among these are an electronic neutron generator to increase sensitivity for deeper and horizontally displaced explosives; LaBr3(Ce) scintillators, to improve time response and energy resolution; improved thermal and electronic stability; improved sensor head geometry to minimize spatial response nonuniformity; and more robust data processing. The sensor is described, with emphasis on the improvements. Experiments to characterize the performance of the second generation TNA in detecting buried landmines and improvised explosive devices (IEDs) hidden in culverts are described. Performance results, including comparisons between the performance of the first and second generation systems are presented.

Analysis of dynamics of vulcanian activity of Ubinas volcano, using multicomponent seismic antennas

NASA Astrophysics Data System (ADS)

Inza, L. A.; Métaxian, J. P.; Mars, J. I.; Bean, C. J.; O'Brien, G. S.; Macedo, O.; Zandomeneghi, D.

2014-01-01

A series of 16 vulcanian explosions occurred at Ubinas volcano between May 24 and June 14, 2009. The intervals between explosions were from 2.1 h to more than 6 days (mean interval, 33 h). Considering only the first nine explosions, the average time interval was 7.8 h. Most of the explosions occurred after a short time interval (< 8 h) and had low energy, which suggests that the refilling time was not sufficient for large accumulation of gas. A tremor episode followed 75% of the explosions, which coincided with pulses of ash emission. The durations of the tremors following the explosions were longer for the two highest energy explosions. To better understand the physical processes associated with these eruptive events, we localized the sources of explosions using two seismic antennas that were composed of three-component 10 and 12 sensors. We used the high-resolution MUSIC-3C algorithm to estimate the slowness vector for the first waves that composed the explosion signals recorded by the two antennas assuming propagation in a homogeneous medium. The initial part of the explosions was dominated by two frequencies, at 1.1 Hz and 1.5 Hz, for which we identified two separated sources located at 4810 m and 3890 m +/- 390 altitude, respectively. The position of these two sources was the same for the full 16 explosions. This implies the reproduction of similar mechanisms in the conduit. Based on the eruptive mechanisms proposed for other volcanoes of the same type, we interpret the position of these two sources as the limits of the conduit portion that was involved in the fragmentation process. Seismic data and ground deformation recorded simultaneously less than 2 km from the crater showed a decompression movement 2 s prior to each explosion. This movement can be interpreted as gas leakage at the level of the cap before its destruction. The pressure drop generated in the conduit could be the cause of the fragmentation process that propagated deeper. Based on these observations, we interpret the position of the highest source as the part of the conduit under the cap, and the deeper source as the limit of the fragmentation zone.

Stratigraphy, sedimentology and eruptive mechanisms in the tuff cone of El Golfo (Lanzarote, Canary Islands)

NASA Astrophysics Data System (ADS)

Pedrazzi, Dario; Martí, Joan; Geyer, Adelina

2013-07-01

The tuff cone of El Golfo on the western coast of Lanzarote (Canary Islands) is a typical hydrovolcanic edifice. Along with other edifices of the same age, it was constructed along a fracture oriented NEE-SWW that coincides with the main structural trend of recent volcanism in this part of the island. We conducted a detailed stratigraphic study of the succession of deposits present in this tuff cone and here interpret them in light of the depositional processes and eruptive dynamics that we were able to infer. The eruptive sequence is represented by a succession of pyroclastic deposits, most of which were emplaced by flow, plus a number of air-fall deposits and ballistic blocks and bombs. We distinguished five different eruptive/depositional stages on the basis of differences in inferred current flow regimes and fragmentation efficiencies represented by the resulting deposits; the different stages may be related to variations in the explosive energy. Eight lithofacies were identified based on sedimentary discontinuities, grain size, components, variations in primary laminations and bedforms. The volcanic edifice was constructed very rapidly around the vent, and this is inferred to have controlled the amount of water that was able to enter the eruption conduit. The sedimentological characteristics of the deposits and the nature and distribution of palagonitic alteration suggest that most of the pyroclastic succession in El Golfo was deposited in a subaerial environment. This type of hydrovolcanic explosive activity is common in the coastal zones of Lanzarote and the other Canary Islands and is one of the main potential hazards that could threaten the human population of this archipelago. Detailed studies of these hydrovolcanic eruptions such as the one we present here can help volcanologists understand the hazards that this type of eruption can generate and provide essential information for undertaking risk assessment in similar volcanic environments.

Consequences of Regional Scale Nuclear Conflicts and Acts of Individual Nuclear Terrorism

NASA Astrophysics Data System (ADS)

Toon, O. B.; Turco, R. P.; Robock, A.; Bardeen, C.; Oman, L.; Stenchikov, G. L.

2006-12-01

The number of nuclear warheads in the world has fallen by about a factor of three since its peak in 1986. However, the potential exists for numerous regional nuclear arms races, and for a significant expansion in the number of nuclear weapons states. Eight countries are known to have nuclear weapons, 2 are constructing them, and an additional 32 nations already have the fissile material needed to build weapons if they so desire. Population and economic activity worldwide are congregated to an increasing extent in "megacities", which are ideal targets for nuclear weapons. We find that low yield weapons, which new nuclear powers are likely to construct, can produce 100 times as many fatalities and 100 times as much smoke from fires per kt yield as high-yield weapons, if they are targeted at city centers. A single low-yield nuclear detonation in an urban center could lead to more fatalities, in some cases by orders of magnitude, than have occurred in major historical conflicts. A regional war between the smallest current nuclear states involving 100 15-kt explosions (less than 0.1% of the explosive yield of the current global nuclear arsenal) could produce direct fatalities comparable to all of those worldwide in World War II (WW-II), or to those once estimated for a "counterforce" nuclear war between the superpowers. Portions of megacities attacked with nuclear devices or exposed to fallout of long-lived isotopes, through armed conflict or terrorism, would likely be abandoned indefinitely, with severe national and international implications. Smoke from urban firestorms in a regional war might induce significant climatic and ozone anomalies on global scales. While there are many uncertainties in the issues we discuss here, the major uncertainties are the type and scale of conflict that might occur. Each of these potential hazards deserves careful analysis by governments worldwide advised by a broad section of the world scientific community, as well as widespread debate.

Wireless system for explosion detection in underground structures

NASA Astrophysics Data System (ADS)

Chikhradze, M.; Bochorishvili, N.; Akhvlediani, I.; Kukhalashvili, D.; Kalichava, I.; Mataradze, E.

2009-06-01

Considering the growing threat of terrorist or accidental explosions in underground stations, underground highway and railway sections improvement of system for protecting people from explosions appears urgent. Current automatic protective devices with blast identification module and blast damping absorbers of various designs as their basic elements cannot be considered effective. Analysis revealed that low reliability of blast detection and delayed generation of start signal for the activation of an absorber are the major disadvantages of protective devices. Besides the transmission of trigger signal to an energy absorber through cable communication reduces the reliability of the operation of protective device due to a possible damage of electric wiring under blast or mechanical attack. This paper presents the outcomes of the studies conducted to select accurate criteria for blast identification and to design wireless system of activation of defensive device. The results of testing of blast detection methods (seismic, EMP, optical, on overpressure) showed that the proposed method, which implies constant monitoring of overpressure in terms of its reliability and response speed, best meets the requirements. Proposed wireless system for explosions identification and activation of protective device consists of transmitter and receiver modules. Transmitter module contains sensor and microprocessor equipped with blast identification software. Receiver module produces activation signal for operation of absorber. Tests were performed in the underground experimental base of Mining Institute. The time between the moment of receiving signal by the sensor and activation of absorber - 640 microsecond; distance between transmitter and receiver in direct tunnel - at least 150m; in tunnel with 900 bending - 50m. This research is sponsored by NATO's Public Diplomacy Division in the framework of "Science for Peace".

Determining Volcanic Deformation at San Miguel Volcano, El Salvador by Integrating Radar Interferometry and Seismic Analyses

NASA Astrophysics Data System (ADS)

Schiek, C. G.; Hurtado, J. M.; Velasco, A. A.; Buckley, S. M.; Escobar, D.

2008-12-01

From the early 1900's to the present day, San Miguel volcano has experienced many small eruptions and several periods of heightened seismic activity, making it one of the most active volcanoes in the El Salvadoran volcanic chain. Prior to 1969, the volcano experienced many explosive eruptions with Volcano Explosivity Indices (VEI) of 2. Since then, eruptions have decreased in intensity to an average VEI of 1. Eruptions mostly consist of phreatic explosions and central vent eruptions. Due to the explosive nature of this volcano, it is important to study the origins of the volcanism and its relationship to surface deformation and earthquake activity. We analyze these interactions by integrating interferometric synthetic aperture radar (InSAR) results with earthquake source location data from a ten-month (March 2007-January 2008) seismic deployment. The InSAR results show a maximum of 7 cm of volcanic inflation from March 2007 to mid-October 2007. During this time, seismic activity increased to a Real-time Seismic-Amplitude Measurement (RSAM) value of >400. Normal RSAM values for this volcano are <50. A period of quiescence began in mid-October 2007, and a maximum of 6 cm of deflation was observed in the interferometry results from 19 October 2007 to 19 January 2008. A clustering of at least 25 earthquakes that occurred between March 2007 and January 2008 suggests a fault zone through the center of the San Miguel volcanic cone. This fault zone is most likely where dyke propagation is occurring. Source mechanisms will be determined for the earthquakes associated with this fault zone, and they will be compared to the InSAR deformation field to determine if the mid-October seismic activity and observed surface deformation are compatible.

Hydrothermal and tectonic activity in northern Yellowstone Lake, Wyoming

USGS Publications Warehouse

Johnson, S.Y.; Stephenson, W.J.; Morgan, L.A.; Shanks, Wayne C.; Pierce, K.L.

2003-01-01

Yellowstone National Park is the site of one of the world's largest calderas. The abundance of geothermal and tectonic activity in and around the caldera, including historic uplift and subsidence, makes it necessary to understand active geologic processes and their associated hazards. To that end, we here use an extensive grid of high-resolution seismic reflection profiles (???450 km) to document hydrothermal and tectonic features and deposits in northern Yellowstone Lake. Sublacustrine geothermal features in northern Yellowstone Lake include two of the largest known hydrothermal explosion craters, Mary Bay and Elliott's. Mary Bay explosion breccia is distributed uniformly around the crater, whereas Elliott's crater breccia has an asymmetric distribution and forms a distinctive, ???2-km-long, hummocky lobe on the lake floor. Hydrothermal vents and low-relief domes are abundant on the lake floor; their greatest abundance is in and near explosion craters and along linear fissures. Domed areas on the lake floor that are relatively unbreached (by vents) are considered the most likely sites of future large hydrothermal explosions. Four submerged shoreline terraces along the margins of northern Yellowstone Lake add to the Holocene record or postglacial lake-level fluctuations attributed to "heavy breathing" of the Yellowstone magma reservoir and associated geothermal system. The Lake Hotel fault cuts through northwestern Yellowstone Lake and represents part of a 25-km-long distributed extensional deformation zone. Three postglacial ruptures indicate a slip rate of ???0.27 to 0.34 mm/yr. The largest (3.0 m slip) and most recent event occurred in the past ???2100 yr. Although high heat flow in the crust limits the rupture area of this fault zone, future earthquakes of magnitude ???5.3 to 6.5 are possible. Earthquakes and hydrothermal explosions have probably triggered landslides, common features around the lake margins. Few high-resolution seismic reflection surveys have been conducted in lakes in active volcanic areas. Our data reveal active geothermal features with unprecedented resolution and provide important analogues for recognition of comparable features and potential hazards in other subaqueous geothermal environments.

Evolution of submarine eruptive activity during the 2011-2012 El Hierro event as documented by hydroacoustic images and remotely operated vehicle observations

NASA Astrophysics Data System (ADS)

Somoza, L.; González, F. J.; Barker, S. J.; Madureira, P.; Medialdea, T.; de Ignacio, C.; Lourenço, N.; León, R.; Vázquez, J. T.; Palomino, D.

2017-08-01

Submarine volcanic eruptions are frequent and important events, yet they are rarely observed. Here we relate bathymetric and hydroacoustic images from the 2011 to 2012 El Hierro eruption with surface observations and deposits imaged and sampled by ROV. As a result of the shallow submarine eruption, a new volcano named Tagoro grew from 375 to 89 m depth. The eruption consisted of two main phases of edifice construction intercalated with collapse events. Hydroacoustic images show that the eruptions ranged from explosive to effusive with variable plume types and resulting deposits, even over short time intervals. At the base of the edifice, ROV observations show large accumulations of lava balloons changing in size and type downslope, coinciding with the area where floating lava balloon fallout was observed. Peaks in eruption intensity during explosive phases generated vigorous bubbling at the surface, extensive ash, vesicular lapilli and formed high-density currents, which together with periods of edifice gravitational collapse, produced extensive deep volcaniclastic aprons. Secondary cones developed in the last stages and show evidence for effusive activity with lava ponds and lava flows that cover deposits of stacked lava balloons. Chaotic masses of heterometric boulders around the summit of the principal cone are related to progressive sealing of the vent with decreasing or variable magma supply. Hornitos represent the final eruptive activity with hydrothermal alteration and bacterial mats at the summit. Our study documents the distinct evolution of a submarine volcano and highlights the range of deposit types that may form and be rapidly destroyed in such eruptions.