Science.gov

Sample records for destructive overpressure events

  1. Realistic Probability Estimates For Destructive Overpressure Events In Heated Center Wing Tanks Of Commercial Jet Aircraft

    SciTech Connect

    Alvares, N; Lambert, H

    2007-02-07

    The Federal Aviation Administration (FAA) identified 17 accidents that may have resulted from fuel tank explosions on commercial aircraft from 1959 to 2001. Seven events involved JP 4 or JP 4/Jet A mixtures that are no longer used for commercial aircraft fuel. The remaining 10 events involved Jet A or Jet A1 fuels that are in current use by the commercial aircraft industry. Four fuel tank explosions occurred in center wing tanks (CWTs) where on-board appliances can potentially transfer heat to the tank. These tanks are designated as ''Heated Center Wing Tanks'' (HCWT). Since 1996, the FAA has significantly increased the rate at which it has mandated airworthiness directives (ADs) directed at elimination of ignition sources. This effort includes the adoption, in 2001, of Special Federal Aviation Regulation 88 of 14 CFR part 21 (SFAR 88 ''Fuel Tank System Fault Tolerance Evaluation Requirements''). This paper addresses SFAR 88 effectiveness in reducing HCWT ignition source probability. Our statistical analysis, relating the occurrence of both on-ground and in-flight HCWT explosions to the cumulative flight hours of commercial passenger aircraft containing HCWT's reveals that the best estimate of HCWT explosion rate is 1 explosion in 1.4 x 10{sup 8} flight hours. Based on an analysis of SFAR 88 by Sandia National Laboratories and our independent analysis, SFAR 88 reduces current risk of historical HCWT explosion by at least a factor of 10, thus meeting an FAA risk criteria of 1 accident in billion flight hours. This paper also surveys and analyzes parameters for Jet A fuel ignition in HCWT's. Because of the paucity of in-flight HCWT explosions, we conclude that the intersection of the parameters necessary and sufficient to result in an HCWT explosion with sufficient overpressure to rupture the HCWT is extremely rare.

  2. Destructive Single-Event Failures in Diodes

    NASA Technical Reports Server (NTRS)

    Casey, Megan C.; Gigliuto, Robert A.; Lauenstein, Jean-Marie; Wilcox, Edward P.; Kim, Hak; Chen, Dakai; Phan, Anthony M.; LaBel, Kenneth A.

    2013-01-01

    In this summary, we have shown that diodes are susceptible to destructive single-event effects, and that these failures occur along the guard ring. By determining the last passing voltages, a safe operating area can be derived. By derating off of those values, rather than by the rated voltage, like what is currently done with power MOSFETs, we can work to ensure the safety of future missions. However, there are still open questions about these failures. Are they limited to a single manufacturer, a small number, or all of them? Is there a threshold rated voltage that must be exceeded to see these failures? With future work, we hope to answer these questions. In the full paper, laser results will also be presented to verify that failures only occur along the guard ring.

  3. Destructive Single-Event Failures in Schottky Diodes

    NASA Technical Reports Server (NTRS)

    Casey, Megan C.; Lauenstein, Jean-Marie; Gigliuto, Robert A.; Wilcox, Edward P.; Phan, Anthony M.; Kim, Hak; Chen, Dakai; LaBel, Kenneth A.

    2014-01-01

    This presentation contains test results for destructive failures in DC-DC converters. We have shown that Schottky diodes are susceptible to destructive single-event effects. Future work will be completed to identify parameter that determines diode susceptibility.

  4. Destructive Single-Event Effects in Diodes

    NASA Technical Reports Server (NTRS)

    Casey, Megan C.; Lauenstein, Jean-Marie; Campola, Michael J.; Wilcox, Edward P.; Phan, Anthony M.; Label, Kenneth A.

    2017-01-01

    In this work, we discuss the observed single-event effects in a variety of types of diodes. In addition, we conduct failure analysis on several Schottky diodes that were heavy-ion irradiated. High- and low-magnitude optical microscope images, infrared camera images, and scanning electron microscope images are used to identify and describe the failure locations.

  5. Functional Interrupts and Destructive Failures from Single Event Effect Testing of Point-Of-Load Devices

    NASA Technical Reports Server (NTRS)

    Chen, Dakai; Phan, Anthony; Kim, Hak; Swonger, James; Musil, Paul; LaBel, Kenneth

    2013-01-01

    We show examples of single event functional interrupt and destructive failure in modern POL devices. The increasing complexity and diversity of the design and process introduce hard SEE modes that are triggered by various mechanisms.

  6. Over-Pressurized Drums: Their Causes and Mitigation

    SciTech Connect

    Simmons, Fred; Kuntamukkula, Murty; Quigley, David; Robertson, Janeen; Freshwater, David

    2009-07-10

    Having to contend with bulging or over-pressurized drums is, unfortunately, a common event for people storing chemicals and chemical wastes. (Figure 1) The Department of Energy alone reported over 120 incidents of bulging drums between 1992 and 1999 (1). Bulging drums can be caused by many different mechanisms, represent a number of significant hazards and can be tricky to mitigate. In this article, we will discuss reasons or mechanisms by which drums can become over-pressurized, recognition of the hazards associated with and mitigation of over-pressurized drums, and methods that can be used to prevent drum over-pressurization from ever occurring. Drum pressurization can represent a significant safety hazard. Unless recognized and properly mitigated, improperly manipulated pressurized drums can result in employee exposure, employee injury, and environmental contamination. Therefore, recognition of when a drum is pressurized and knowledge of pressurized drum mitigation techniques is essential.

  7. Overpressure by burial

    NASA Astrophysics Data System (ADS)

    Podladchikov, Yury; Dabrowski, Marcin

    2017-04-01

    Preservation of peak metamorphic assemblages cannot be explain by sluggish kinetics only due to high temperatures. Moreover, frequently reported near isothermal decompression from peak conditions testify continuing capacity of lower pressure metamorphic reactions to overcome kinetic barriers. Often these observations come from the same rock sample, or even or from a single host crystal. Natural conclusion on preservation of peak pressures in a 'pressure vessel' in order to preserve the peak mineral assemblages was firmly made already in the first years after convincing identifying of ultra-high pressure minerals in continental rocks. The 'pressure vessels' model is thus the current view on mechanical state during retrogression assuming up to several GPa excess pressure in inclusion maintained by host mineral all the way through retrogression. Same arguments apply to preservation of outcrop scale eclogite boudins in lower pressure amphibolite gneisses. If strength of rocks and minerals is sufficient to keep the pressure difference during retrogression, the same applies to the prograde stage of the metamorphic history of the rock. We investigate and quantify the overpressure development during burial of continental rocks. We show that eclogite lenses are expected to develop over mafic lithology embedded in average crustal rock at lower crustal condition, thus eliminating the need for 'deep continental subduction' as the only mechanism to form it.

  8. The interdisciplinary use of ;overpressure;

    NASA Astrophysics Data System (ADS)

    Peacock, D. C. P.; Anderson, M. W.; Rotevatn, A.; Sanderson, D. J.; Tavarnelli, E.

    2017-07-01

    Overpressure is a polysemic word that has a variety of meanings within and across different disciplines. This is likely to be a particular problem in analysis of geothermal resources, where reservoir engineers, volcanologists and structural geologists may each confidently use overpressure but mean different things. We suggest that, to avoid confusion, the term should be carefully and accurately defined whenever used, and ideally only used to mean fluid pressure in excess of hydrostatic pressure.

  9. Toxicology of blast overpressure.

    PubMed

    Elsayed, N M

    1997-07-25

    Blast overpressure (BOP) or high energy impulse noise, is the sharp instantaneous rise in ambient atmospheric pressure resulting from explosive detonation or firing of weapons. Blasts that were once confined to military and to a lesser extent, occupational settings, are becoming more universal as the civilian population is now increasingly at risk of exposure to BOP from terrorist bombings that are occurring worldwide with greater frequency. Exposure to incident BOP waves can cause auditory and non-auditory damage. The primary targets for BOP damage are the hollow organs, ear, lung and gastrointestinal tract. In addition, solid organs such as heart, spleen and brain can also be injured upon exposure. However, the lung is more sensitive to damage and its injury can lead to death. The pathophysiological responses, and mortality have been extensively studied, but little attention, was given to the biochemical manifestations, and molecular mechanism(s) of injury. The injury from BOP has been, generally, attributed to its external physical impact on the body causing internal mechanical damage. However, a new hypothesis has been proposed based on experiments conducted in the Department of Respiratory Research, Walter Reed Army Institute of Research, and later in the Department of Occupational Health, University of Pittsburgh. This hypothesis suggests that subtle biochemical changes namely, free radical-mediated oxidative stress occur and contribute to BOP-induced injury. Understanding the etiology of these changes may shed new light on the molecular mechanism(s) of injury, and can potentially offer new strategies for treatment. In this symposium. BOP research involving auditory, non-auditory, physiological, pathological, behavioral, and biochemical manifestations as well as predictive modeling and current treatment modalities of BOP-induced injury are discussed.

  10. Impact of dynamically induced ozone mini-hole events on PSC formation and chemical ozone destruction

    NASA Astrophysics Data System (ADS)

    Stenke, A.; Grewe, V.

    2004-01-01

    The impact of ozone mini-holes over the extra-tropics of the northern hemisphere on the heterogeneous ozone chemistry is investigated, based on simulations with the coupled climate-chemistry model ECHAM4.L39(DLR)/CHEM. Ozone mini-holes are synoptic-scale regions of strongly reduced total ozone, directly associated with upper troposphere high pressure systems. The simulated mini-hole events are validated with a mini-hole climatology based on daily ozone measurements with the total ozone mapping spectrometer (TOMS) instrument on the satellite Nimbus-7 between 1979 and 1993. Furthermore, the impact of mini-holes on the stratospheric heterogeneous ozone chemistry is investigated indirectly. For this purpose, polar stratospheric cloud formation inside mini-holes is suppressed during the model simulation. Heterogeneous processes inside mini-holes amount to one third of the heterogeneous ozone destruction in general over northern mid- and high-latitudes during winter (January-April). This ozone perturbation subsides and recovers during summer with an e-folding time of two months.

  11. Magnetic latches provide positive overpressure control

    NASA Technical Reports Server (NTRS)

    Loy, J. L.

    1966-01-01

    Louvers are used for overpressure safety venting in rooms or chambers where explosion hazards exist. The louvers have individually hinged closures that are held in locked position by commercially available magnets that quickly release them in an overpressure condition.

  12. Effects of Filtering on Experimental Blast Overpressure Measurements.

    PubMed

    Alphonse, Vanessa D; Kemper, Andrew R; Duma, Stefan M

    2015-01-01

    When access to live-fire test facilities is limited, experimental studies of blast-related injuries necessitate the use of a shock tube or Advanced Blast Simulator (ABS) to mimic free-field blast overpressure. However, modeling blast overpressure in a laboratory setting potentially introduces experimental artifacts in measured responses. Due to the high sampling rates required to capture a blast overpressure event, proximity to alternating current (AC-powered electronics) and poorly strain-relieved or unshielded wires can result in artifacts in the recorded overpressure trace. Data in this study were collected for tests conducted on an empty ABS (“Empty Tube”) using high frequency pressure sensors specifically designed for blast loading rates (n=5). Additionally, intraocular overpressure data (“IOP”) were collected for porcine eyes potted inside synthetic orbits located inside the ABS using an unshielded miniature pressure sensor (n=3). All tests were conducted at a 30 psi static overpressure level. A 4th order phaseless low pass Butterworth software filter was applied to the data. Various cutoff frequencies were examined to determine if the raw shock wave parameters values could be preserved while eliminating noise and artifacts. A Fast Fourier Transform (FFT) was applied to each test to examine the frequency spectra of the raw and filtered signals. Shock wave parameters (time of arrival, peak overpressure, positive duration, and positive impulse) were quantified using a custom MATLAB® script. Lower cutoff frequencies attenuated the raw signal, effectively decreasing the peak overpressure and increasing the positive duration. Rise time was not preserved the filtered data. A CFC 6000 filter preserved the remaining shock wave parameters within ±2.5% of the average raw values for the Empty Tube test data. A CFC 7000 filter removed experimental high-frequency artifacts and preserved the remaining shock wave parameters within ±2.5% of the average raw values for

  13. Peak Overpressures for Internal Blast

    DTIC Science & Technology

    1979-06-01

    reactions such as formation of aluminum oxide. The slow pressure-decay rates for internal explosions leid to relatively long overpressure duration times that...1750 6.61 2205 .21 7.9 5.59 1941 7.19 2408 .18 6.9 6.13 2007 7.70 2643 .23 9.4 6.23 2122 7.89 2586 .23 9.4 5.45 2186 7.89 25Ś .17 9.4 6.23 2124 7.89

  14. Space Launch System Scale Model Acoustic Test Ignition Overpressure Testing

    NASA Technical Reports Server (NTRS)

    Nance, Donald K.; Liever, Peter A.

    2015-01-01

    The overpressure phenomenon is a transient fluid dynamic event occurring during rocket propulsion system ignition. This phenomenon results from fluid compression of the accelerating plume gas, subsequent rarefaction, and subsequent propagation from the exhaust trench and duct holes. The high-amplitude unsteady fluid-dynamic perturbations can adversely affect the vehicle and surrounding structure. Commonly known as ignition overpressure (IOP), this is an important design-to environment for the Space Launch System (SLS) that NASA is currently developing. Subscale testing is useful in validating and verifying the IOP environment. This was one of the objectives of the Scale Model Acoustic Test (SMAT), conducted at Marshall Space Flight Center (MSFC). The test data quantifies the effectiveness of the SLS IOP suppression system and improves the analytical models used to predict the SLS IOP environments. The reduction and analysis of the data gathered during the SMAT IOP test series requires identification and characterization of multiple dynamic events and scaling of the event waveforms to provide the most accurate comparisons to determine the effectiveness of the IOP suppression systems. The identification and characterization of the overpressure events, the waveform scaling, the computation of the IOP suppression system knockdown factors, and preliminary comparisons to the analytical models are discussed.

  15. Space Launch System Scale Model Acoustic Test Ignition Overpressure Testing

    NASA Technical Reports Server (NTRS)

    Nance, Donald; Liever, Peter; Nielsen, Tanner

    2015-01-01

    The overpressure phenomenon is a transient fluid dynamic event occurring during rocket propulsion system ignition. This phenomenon results from fluid compression of the accelerating plume gas, subsequent rarefaction, and subsequent propagation from the exhaust trench and duct holes. The high-amplitude unsteady fluid-dynamic perturbations can adversely affect the vehicle and surrounding structure. Commonly known as ignition overpressure (IOP), this is an important design-to environment for the Space Launch System (SLS) that NASA is currently developing. Subscale testing is useful in validating and verifying the IOP environment. This was one of the objectives of the Scale Model Acoustic Test, conducted at Marshall Space Flight Center. The test data quantifies the effectiveness of the SLS IOP suppression system and improves the analytical models used to predict the SLS IOP environments. The reduction and analysis of the data gathered during the SMAT IOP test series requires identification and characterization of multiple dynamic events and scaling of the event waveforms to provide the most accurate comparisons to determine the effectiveness of the IOP suppression systems. The identification and characterization of the overpressure events, the waveform scaling, the computation of the IOP suppression system knockdown factors, and preliminary comparisons to the analytical models are discussed.

  16. Coping with unfair events constructively or destructively: the effects of overall justice and self-other orientation.

    PubMed

    Bobocel, D Ramona

    2013-09-01

    Drawing on fairness heuristic theory (Lind, 2001, 2002), it was predicted that how employees cope with an unfair event-whether they are more or less forgiving, and whether they are more or less vengeful-will depend jointly on (a) their perceptions of overall organizational justice and (b) the degree to which they focus on their own interests or on the interests of others. Data were collected in a 2-part field survey of 153 employees who reported their responses to a recent unfair event. Hierarchical regression analyses (controlling possible 3rd variable explanations) revealed the 2 predicted 2-way interactions. Perceptions of overall organizational justice (a) facilitated forgiveness among those with strong other-orientation, and (b) suppressed revenge among those with strong self-concern. Together, the data suggest that perceiving one's organization as a fair entity can shape proximal responses to unfair events, simultaneously facilitating constructive responses in some employees, and suppressing destructive responses in other employees. Theoretically, the findings are consistent with the idea that overall justice fulfills psychological needs that are differentially relevant to employees as a function of their chronic attention to others or to themselves, which in turn enables them to cope with unfair events more beneficially. The data have implications for the study of workplace forgiveness and revenge, as well as more broadly for the literatures on organizational justice and workplace mistreatment. PsycINFO Database Record (c) 2013 APA, all rights reserved

  17. Weapons of Mass Destruction Events With Contaminated Casualties: Effective Planning for Health Care Facilities

    DTIC Science & Technology

    2000-01-12

    for Metropolitan MedicalStrikeTeams,43whichwerecom- posed of specially trained local person- nelwereorganized tohelpcommunities respond to events...munityresponseentities, includingemer- gencymanagement, lawenforcement ,fire, andmedicalpersonnel.Thecurrentpro- gramforhospitalpersonnelhaslackedde- tailed...yet been reached on this controversial point. This issue should be addressed through compre- hensive planning that includes local en- vironmental and

  18. Apparatus for reducing shock and overpressure

    DOEpatents

    Walter, C.E.

    1975-01-28

    An apparatus for reducing shock and overpressure is particularly useful in connection with the sequential detonation of a series of nuclear explosives under ground. A coupling and decoupling arrangement between adjacent nuclear explosives in the tubing string utilized to emplace the explosives is able to support lower elements on the string but yields in a manner which absorbs energy when subjected to the shock wave produced upon detonation of one of the explosives. Overpressure is accomodated by an arrangement in the string which provides an additional space into which the pressurized material can expand at a predetermined overpressure. (10 claims)

  19. Apparatus for reducing shock and overpressure

    DOEpatents

    Walter, C.E.

    1975-10-21

    The design is given of an apparatus for reducing shock and overpressure particularly useful in connection with the sequential detonation of a series of nuclear explosives underground. A coupling and decoupling arrangement between adjacent nuclear explosives in the tubing string utilized to emplace the explosives is able to support lower elements on the string but yields in a manner which absorbs energy when subjected to the shock wave produced upon detonation of one of the explosives. Overpressure is accommodated by an arrangement in the string which provides an additional space into which the pressurized material can expand at a predetermined overpressure.

  20. The Destruction of Thin Stellar Disks Via Cosmologically Common Satellite Accretion Events

    NASA Astrophysics Data System (ADS)

    Purcell, Chris W.; Kazantzidis, Stelios; Bullock, James S.

    2009-04-01

    Most Galaxy-sized systems (M host sime 1012 M sun) in the ΛCDM cosmology are expected to have interacted with at least one satellite with a total mass M sat sime 1011 M sun sime 3M disk in the past 8 Gyr. Analytic and numerical investigations suggest that this is the most precarious type of accretion for the survival of thin galactic disks because more massive accretion events are relatively rare and less massive ones preserve thin disk components. We use high-resolution, dissipationless N-body simulations to study the response of an initially thin, fully formed Milky Way-type stellar disk to these cosmologically common satellite accretion events, and show that the thin disk does not survive. Regardless of orbital configuration, the impacts transform the disks into structures that are roughly three times as thick and more than twice as kinematically hot as the observed dominant thin disk component of the Milky Way. We conclude that if the Galactic thin disk is a representative case, then the presence of a stabilizing gas component is the only recourse for explaining the preponderance of disk galaxies in a ΛCDM universe; otherwise, the disk of the Milky Way must be uncommonly cold and thin for its luminosity, perhaps as a consequence of an unusually quiescent accretion history.

  1. An experimental study of non-destructive testing on glass fibre reinforced polymer composites after high velocity impact event

    NASA Astrophysics Data System (ADS)

    Razali, N.; Sultan, M. T. H.; Cardona, F.

    2016-10-01

    A non-destructive testing method on Glass Fibre Reinforced Polymer (GFRP) after high velocity impact event using single stage gas gun (SSGG) is presented. Specimens of C- type and E-type fibreglass reinforcement, which were fabricated with 6mm, 8mm, 10mm and 12mm thicknesses and size 100 mm x 100 mm, were subjected to a high velocity impact with three types of bullets: conical, hemispherical and blunt at various gas gun pressure levels from 6 bar to 60 bar. Visual observation techniques using a lab microscope were used to determine the infringed damage by looking at the crack zone. Dye penetrants were used to inspect the area of damage, and to evaluate internal and external damages on the specimens after impact. The results from visual analysis of the impacted test laminates were discussed and presented. It was found that the impact damage started with induced delamination, fibre cracking and then failure, simultaneously with matrix cracking and breakage, and finally followed by the fibres pulled out. C-type experienced more damaged areas compared to E-type of GFRP.

  2. Just-in-time learning is effective in helping first responders manage weapons of mass destruction events.

    PubMed

    Motola, Ivette; Burns, William A; Brotons, Angel A; Withum, Kelly F; Rodriguez, Richard D; Hernandez, Salma; Rivera, Hector F; Issenberg, Saul Barry; Schulman, Carl I

    2015-10-01

    Chemical, biologic, radiologic, nuclear, and explosive (CBRNE) incidents require specialized training. The low frequency of these events leads to significant skill decay among first responders. To address skill decay and lack of experience with these high-impact events, educational modules were developed for mobile devices to provide just-in-time training to first responders en route to a CBRNE event. This study assessed the efficacy and usability of the mobile training. Ninety first responders were randomized to a control or an intervention group. All participants completed a pretest to measure knowledge of CBRNE topics. The intervention group then viewed personal protective equipment and weapons of mass destruction field management videos as an overview. Both groups were briefed on a disaster scenario (chemical nerve agent, radiologic, or explosives) requiring them to triage, assess, and manage a patient. Intervention group participants watched a mobile training video corresponding to the scenario. The control group did not receive prescenario video training. Observers rated participant performance in each scenario. After completing the scenarios, all participants answered a cognitive posttest. Those in the intervention group also answered a questionnaire on their impressions of the training. The intervention group outperformed the control group in the explosives and chemical nerve agent scenarios; the differences were statistically significant (explosives, mean of 26.32 for intervention and 22.85 for control, p < 0.01; nerve agent, mean of 23.14 for intervention and 16.61 for control, p < 0.01). There was no statistically significant difference between the groups in the radiologic scenario (mean, 12.7 for intervention and 11.8 for control; p = 0.51). The change in pretest to posttest cognitive scores was significantly higher in the intervention group than in the control group (t = 3.28, p < 0.05). Mobile just-in-time training improved first-responder knowledge

  3. Glacially Generated Overpressure Offshore Massachusetts, USA: Integration of Full Seismic Waveform Inversion and Overpressure Modeling

    NASA Astrophysics Data System (ADS)

    Siegel, J. E.; Lizarralde, D.; Dugan, B.; Person, M. A.

    2012-12-01

    Localized, high-amplitude reflections, overlying a late Pleistocene glacial erosion surface 100 km offshore Massachusetts, USA, have lower compressional wave velocities of up to 200 m/s compared to adjacent sediments of equal depth. This may be the result of lower effective stress from overpressures as high as 1 MPa. To investigate the origin of these low velocity zones, we compare the detailed velocity structure across the high-amplitude regions to adjacent, undisturbed regions through a full waveform inversion, and we forward model the effective stress and overpressure. We relate the full waveform inversion velocities to effective stress with a power-law model. This model predicts effective stresses are 0.6 MPa at 250 m below the sea floor, which equates to an overpressure of 1.0 MPa. To help understand the overpressure source, we model the pressure response to erosion, glacial loading, and sedimentation in 1D. Preliminary models show that late Pleistocene glaciations, including the Last Glacial Maximum (LGM), and rapid sedimentation from glacial lake drainage may be important mechanisms for the generation of the localized regions of high overpressure. Our geophysical observations and interpretations suggest overpressure exists offshore today. Our forward models predict that this overpressure originated during the LGM due to pore pressure generation from rapid loading by glacial ice, however these overpressures are dissipating in the modern, low sedimentation rate environment. These shallow overpressures provide a mechanism to explain the SGD inferred along the Northern Atlantic continental shelf. Our results also provide physical-property observables, specific to location, that can constrain ongoing 3D numerical modeling efforts to deterministically predict the hydrologic history of the continental shelf sediments based on detailed stratigraphic and ice-sheet evolution.

  4. Development of space shuttle ignition overpressure environment and correlation with flight data

    NASA Technical Reports Server (NTRS)

    Lai, S.

    1983-01-01

    The Space Transportation (STS) launch vehicles are more complex than other launch vehicles. A comprehensive analysis of the lift-off event is required so that the responses of the vehicle and payloads can be predicted. The transient overpressure induced by ignition of the solid rocket motors (SRM's) is one of the critical design factors assessed for lift-off. The STS-1 ignition overpressure design environment was developed from 6.4-percent scale-model tests in which the Tomahawk solid rocket motors were used to simulate the start-up process of the SRM's. The overpressures measured during STS-1 lift-off were much more severe than predicted. The reasons for this anomaly are discussed in this paper. The 6.4-percent scale model was redesigned and used as a tool to develop an effective ignition overpressure suppression system for STS-2 and subsequent flights. Also presented are advancements in subscale-model simulation and theoretical understanding of this transient overpressure phenomenon that led to the successful development of the fix.

  5. Single-Event Effect Report for EPC Series eGaN FETs: Comparison of EPC1000 and EPC2000 Series Devices for Destructive SEE

    NASA Technical Reports Server (NTRS)

    Scheick, Leif

    2014-01-01

    Recent testing of the EPC1000 series eGaN FETs has shown sensitivity to Single Event Effects (SEE) that are destructive. These effects are most likely the failure of the very thin gate structure in HEMT architecture. EPC has recently changed the doping of the substrate to improve the performance and the SEE response. This testing compares the SEE response of both devices.

  6. Mechanisms for generating overpressure in sedimentary basins: A reevaluation

    SciTech Connect

    Osborne, M.J.; Swarbrick, R.E.

    1997-06-01

    Overpressure can be produced by the following processes: (1) increase of compressive stress, (2) changes in the volume of the pore fluid or rock matrix, and (3) fluid movement or buoyancy. Loading during burial can generate considerable overpressure due to disequilibrium compaction, particularly during the rapid subsidence of low-permeability sediments. Horizontal stress changes can rapidly generate and dissipate large amounts of overpressure in tectonically active areas. Overpressure mechanisms involving change in volume must be well sealed to be effective. Fluid volume increases associated with aquathermal expansion and clay dehydration are too small to generate significant overpressure unless perfect sealing occurs. Hydrocarbon generation and cracking to gas could possibly produce overpressure, depending upon the kerogen type, abundance of organic matter, temperature history, and rock permeability; however, these processes may be self-limiting in a sealed system because buildup of pressure could inhibit further organic metamorphism. The potential for generating overpressure by hydrocarbon generation and cracking must be regarded as unproven at present. Fluid movement due to a hydraulic head can generate significant overpressure in shallowly buried, {open_quotes}well-plumbed{close_quotes} basins. Calculations indicate that hydrocarbon buoyancy and osmosis can generate only small amounts of localized overpressure. The upward movement of gas in an incompressible fluid also could generate significant overpressure, but requires further investigation. Stress-related mechanisms are the most likely causes of overpressure in many sedimentary basins.

  7. Visual system degeneration induced by blast overpressure.

    PubMed

    Petras, J M; Bauman, R A; Elsayed, N M

    1997-07-25

    The effect of blast overpressure on visual system pathology was studied in 14 male Sprague-Dawley rats weighing 360-432 g. Blast overpressure was simulated using a compressed-air driven shock tube, with the aim of studying a range of overpressures causing sublethal injury. Neither control (unexposed) rats nor rats exposed to 83 kiloPascals (kPa) overpressure showed evidence of visual system pathology. Neurological injury to brain visual pathways was observed in male rats surviving blast overpressure exposures of 104-110 kPa and 129-173 kPa. Optic nerve fiber degeneration was ipsilateral to the blast pressure wave. The optic chiasm contained small numbers of degenerated fibers. Optic tract fiber degeneration was present bilaterally, but was predominantly ipsilateral. Optic tract fiber degeneration was followed to nuclear groups at the level of the midbrain, midbrain-diencephalic junction, and the thalamus where degenerated fibers arborized among the neurons of: (i) the superior colliculus, (ii) pretectal region, and (iii) the lateral geniculate body. The superior colliculus contained fiber degeneration localized principally to two superficial layers (i) the stratum opticum (layer III) and (ii) stratum cinereum (layer II). The pretectal area contained degenerated fibers which were widespread in (i) the nucleus of the optic tract, (ii) olivary pretectal nucleus, (iii) anterior pretectal nucleus, and (iv) the posterior pretectal nucleus. Degenerated fibers in the lateral geniculate body were not universally distributed. They appeared to arborize among neurons of the dorsal and ventral nuclei: the ventral lateral geniculate nucleus (parvocellular and magnocellular parts); and the dorsal lateral geniculate nucleus. The axonopathy observed in the central visual pathways and nuclei of the rat brain are consistent with the presence of blast overpressure induced injury to the retina. The orbital cavities of the human skull contain frontally-directed eyeballs for binocular

  8. Elastic properties of overpressured and unconsolidated sediments

    USGS Publications Warehouse

    Lee, Myung W.

    2003-01-01

    Differential pressure affects elastic velocities and Poisson?s ratio of sediments in such a way that velocities increase as differential pressure increases. Overpressured zones in sediments can be detected by observing an increase in Poisson?s ratio with a corresponding drop in elastic velocities. In highly overpressured sands, such as shallow water flow sands, the P-to S-wave velocity ratio (Vp/Vs) is very high, on the order of 10 or higher, due to the unconsolidated and uncemented nature of sediments. In order to predict elastic characteristics of highly overpressured sands, Biot-Gassmann theory by Lee (BGTL) is used with a variable exponent n that depends on differential pressure and the degree of consolidation/compaction. The exponent n decreases as differential pressure and the degree of consolidation increases, and, as n decreases, velocity increases and Vp/Vs decreases. The predicted velocity ratio by BGTL agrees well with the measured velocity ratio at low differential pressure for unconsolidated sediments.

  9. Coasting after overpressure induction with sevoflurane.

    PubMed

    Hendrickx, J F; Vandeput, D M; De Geyndt, A M; DeLoof, T; De Wolf, A M

    2000-03-01

    To evaluate the clinical feasibility of using a coasting technique to temporarily maintain anesthesia after overpressure induction with sevoflurane. Prospective clinical study. Large teaching hospital. 12 ASA physical status I, II, and III patients receiving general anesthesia for a variety of peripheral procedures. After overpressure induction of anesthesia with sevoflurane (8%) in an O(2)/N(2)O mixture, the fresh gas flow (FGF) was lowered to 0.5 L/min and the vaporizer was turned off (coasting). After priming a circle system with sevoflurane (8% sevoflurane vaporizer setting in 6 L/min O(2)/N(2)O [33%/66%] for 30 s), patients took several vital capacity breaths from the mixture until loss of consciousness. After 3.4 +/- 0.7 min, depth of anesthesia was considered adequate for laryngeal mask airway (LMA) insertion, and FGF was reduced to 0.5 L/min (33% O(2), 66% N(2)O) and the sevoflurane vaporizer was turned off. The end-expired sevoflurane concentration (Et(sevo)) decreased from 5.8 +/- 1.3% just before insertion of the LMA to 0.97 +/- 0.22% at 20 minutes. After overpressure induction with sevoflurane, coasting during minimal flow anesthesia (FGF 0.5 L/min) is a simple technique that can maintain anesthesia for short procedures (less than 15 to 20 min), or can be used as a bridge or an adjunct to other low-flow techniques.

  10. Simulation Assisted Risk Assessment: Blast Overpressure Modeling

    NASA Technical Reports Server (NTRS)

    Lawrence, Scott L.; Gee, Ken; Mathias, Donovan; Olsen, Michael

    2006-01-01

    A probabilistic risk assessment (PRA) approach has been developed and applied to the risk analysis of capsule abort during ascent. The PRA is used to assist in the identification of modeling and simulation applications that can significantly impact the understanding of crew risk during this potentially dangerous maneuver. The PRA approach is also being used to identify the appropriate level of fidelity for the modeling of those critical failure modes. The Apollo launch escape system (LES) was chosen as a test problem for application of this approach. Failure modes that have been modeled and/or simulated to date include explosive overpressure-based failure, explosive fragment-based failure, land landing failures (range limits exceeded either near launch or Mode III trajectories ending on the African continent), capsule-booster re-contact during separation, and failure due to plume-induced instability. These failure modes have been investigated using analysis tools in a variety of technical disciplines at various levels of fidelity. The current paper focuses on the development and application of a blast overpressure model for the prediction of structural failure due to overpressure, including the application of high-fidelity analysis to predict near-field and headwinds effects.

  11. The pathology of primary blast overpressure injury.

    PubMed

    Mayorga, M A

    1997-07-25

    Primary blast injury occurs in civilian and military detonations and from the firing of weapon systems. The pathology of primary blast injury has been reported for the last 70 years and has primarily been limited to descriptions of gross pathology and histology. Commonly accepted tenets have not been confirmed as blast overpressure experiments in enclosures and with multiple detonations have been conducted. Organ systems other than the ear and the lung are playing a greater role in injury definition and research importance. This paper is an overview and update of the current understanding of the pathology of primary blast injury.

  12. 5 Percent Ares I Scale Model Acoustic Test: Overpressure Characterization and Analysis

    NASA Technical Reports Server (NTRS)

    Alvord, David; Casiano, Matthew; McDaniels, Dave

    2011-01-01

    During the ignition of a ducted solid rocket motor (SRM), rapid expansion of injected hot gases from the motor into a confined volume causes the development of a steep fronted wave. This low frequency transient wave propagates outward from the exhaust duct, impinging the vehicle and ground structures. An unsuppressed overpressure wave can potentially cause modal excitation in the structures and vehicle, subsequently leading to damage. This presentation details the ignition transient f indings from the 5% Ares I Scale Model Acoustic Test (ASMAT). The primary events of the ignition transient environment induced by the SRM are the ignition overpressure (IOP), duct overpressure (DOP), and source overpressure (SOP). The resulting observations include successful knockdown of the IOP environment through use of a Space Shuttle derived IOP suppression system, a potential load applied to the vehicle stemming from instantaneous asymmetrical IOP and DOP wave impingement, and launch complex geometric influences on the environment. The results are scaled to a full-scale Ares I equivalent and compared with heritage data including Ares I-X and both suppressed and unsuppressed Space Shuttle IOP environments.

  13. Rupture threshold characterization of polymer-shelled ultrasound contrast agents subjected to static overpressure

    PubMed Central

    Chitnis, Parag V.; Lee, Paul; Mamou, Jonathan; Allen, John S.; Böhmer, Marcel; Ketterling, Jeffrey A.

    2011-01-01

    Polymer-shelled micro-bubbles are employed as ultrasound contrast agents (UCAs) and vesicles for targeted drug delivery. UCA-based delivery of the therapeutic payload relies on ultrasound-induced shell rupture. The fragility of two polymer-shelled UCAs manufactured by Point Biomedical or Philips Research was investigated by characterizing their response to static overpressure. The nominal diameters of Point and Philips UCAs were 3 μm and 2 μm, respectively. The UCAs were subjected to static overpressure in a glycerol-filled test chamber with a microscope-reticule lid. UCAs were reconstituted in 0.1 mL of water and added over the glycerol surface in contact with the reticule. A video-microscope imaged UCAs as glycerol was injected (5 mL∕h) to vary the pressure from 2 to 180 kPa over 1 h. Neither UCA population responded to overpressure until the rupture threshold was exceeded, which resulted in abrupt destruction. The rupture data for both UCAs indicated three subclasses that exhibited different rupture behavior, although their mean diameters were not statistically different. The rupture pressures provided a measure of UCA fragility; the Philips UCAs were more resilient than Point UCAs. Results were compared to theoretical models of spherical shells under compression. Observed variations in rupture pressures are attributed to shell imperfections. These results may provide means to optimize polymeric UCAs for drug delivery and elucidate associated mechanisms. PMID:21580800

  14. Rupture threshold characterization of polymer-shelled ultrasound contrast agents subjected to static overpressure.

    PubMed

    Chitnis, Parag V; Lee, Paul; Mamou, Jonathan; Allen, John S; Böhmer, Marcel; Ketterling, Jeffrey A

    2011-04-15

    Polymer-shelled micro-bubbles are employed as ultrasound contrast agents (UCAs) and vesicles for targeted drug delivery. UCA-based delivery of the therapeutic payload relies on ultrasound-induced shell rupture. The fragility of two polymer-shelled UCAs manufactured by Point Biomedical or Philips Research was investigated by characterizing their response to static overpressure. The nominal diameters of Point and Philips UCAs were 3 μm and 2 μm, respectively. The UCAs were subjected to static overpressure in a glycerol-filled test chamber with a microscope-reticule lid. UCAs were reconstituted in 0.1 mL of water and added over the glycerol surface in contact with the reticule. A video-microscope imaged UCAs as glycerol was injected (5 mL∕h) to vary the pressure from 2 to 180 kPa over 1 h. Neither UCA population responded to overpressure until the rupture threshold was exceeded, which resulted in abrupt destruction. The rupture data for both UCAs indicated three subclasses that exhibited different rupture behavior, although their mean diameters were not statistically different. The rupture pressures provided a measure of UCA fragility; the Philips UCAs were more resilient than Point UCAs. Results were compared to theoretical models of spherical shells under compression. Observed variations in rupture pressures are attributed to shell imperfections. These results may provide means to optimize polymeric UCAs for drug delivery and elucidate associated mechanisms.

  15. Rupture threshold characterization of polymer-shelled ultrasound contrast agents subjected to static overpressure

    NASA Astrophysics Data System (ADS)

    Chitnis, Parag V.; Lee, Paul; Mamou, Jonathan; Allen, John S.; Böhmer, Marcel; Ketterling, Jeffrey A.

    2011-04-01

    Polymer-shelled micro-bubbles are employed as ultrasound contrast agents (UCAs) and vesicles for targeted drug delivery. UCA-based delivery of the therapeutic payload relies on ultrasound-induced shell rupture. The fragility of two polymer-shelled UCAs manufactured by Point Biomedical or Philips Research was investigated by characterizing their response to static overpressure. The nominal diameters of Point and Philips UCAs were 3 μm and 2 μm, respectively. The UCAs were subjected to static overpressure in a glycerol-filled test chamber with a microscope-reticule lid. UCAs were reconstituted in 0.1 mL of water and added over the glycerol surface in contact with the reticule. A video-microscope imaged UCAs as glycerol was injected (5 mL/h) to vary the pressure from 2 to 180 kPa over 1 h. Neither UCA population responded to overpressure until the rupture threshold was exceeded, which resulted in abrupt destruction. The rupture data for both UCAs indicated three subclasses that exhibited different rupture behavior, although their mean diameters were not statistically different. The rupture pressures provided a measure of UCA fragility; the Philips UCAs were more resilient than Point UCAs. Results were compared to theoretical models of spherical shells under compression. Observed variations in rupture pressures are attributed to shell imperfections. These results may provide means to optimize polymeric UCAs for drug delivery and elucidate associated mechanisms.

  16. Evolution of overpressured and underpressured oil and gas reservoirs, Anadarko Basin of Oklahoma, Texas, and Kansas

    USGS Publications Warehouse

    Nelson, Phillip H.; Gianoutsos, Nicholas J.

    2011-01-01

    Departures of resistivity logs from a normal compaction gradient indicate that overpressure previously extended north of the present-day overpressured zone. These indicators of paleopressure, which are strongest in the deep basin, are mapped to the Kansas-Oklahoma border in shales of Desmoinesian age. The broad area of paleopressure has contracted to the deep basin, and today the overpressured deep basin, as determined from drillstem tests, is bounded on the north by strata with near normal pressures (hydrostatic), grading to the northwest to pressures that are less than hydrostatic (underpressured). Thus the pressure regime in the northwest portion of the Anadarko Basin has evolved from paleo-overpressure to present-day underpressure. Using pressure data from drillstem tests, we constructed cross sections and potentiometric maps that illustrate the extent and nature of present-day underpressuring. Downcutting and exposure of Lower Permian and Pennsylvanian strata along, and east of, the Nemaha fault zone in central Oklahoma form the discharge locus where pressure reaches near atmospheric. From east to west, hydraulic head increases by several hundred feet in each rock formation, whereas elevation increases by thousands of feet. The resulting underpressuring of the aquifer-supported oil and gas fields, which also increases from east to west, is a consequence of the vertical separation between surface elevation and hydraulic head. A 1,000-ft thick cap of Permian evaporites and shales isolates the underlying strata from the surface, preventing re-establishment of a normal hydrostatic gradient. Thus, the present-day pressure regime of oil and gas reservoirs, overpressured in the deep basin and underpressured on the northwest flank of the basin, is the result of two distinct geologic events-rapid burial and uplift/erosion-widely separated in time.

  17. 46 CFR 153.365 - Liquid overpressurization protection.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Liquid overpressurization protection. 153.365 Section... CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Venting Systems § 153.365 Liquid overpressurization protection. (a) Except as noted...

  18. 46 CFR 153.365 - Liquid overpressurization protection.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Liquid overpressurization protection. 153.365 Section... CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Venting Systems § 153.365 Liquid overpressurization protection. (a) Except as noted...

  19. 46 CFR 153.365 - Liquid overpressurization protection.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Liquid overpressurization protection. 153.365 Section... CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Venting Systems § 153.365 Liquid overpressurization protection. (a) Except as noted...

  20. 46 CFR 153.365 - Liquid overpressurization protection.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Liquid overpressurization protection. 153.365 Section... CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Venting Systems § 153.365 Liquid overpressurization protection. (a) Except as noted...

  1. 46 CFR 153.365 - Liquid overpressurization protection.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Liquid overpressurization protection. 153.365 Section... CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Venting Systems § 153.365 Liquid overpressurization protection. (a) Except as noted...

  2. 49 CFR 192.195 - Protection against accidental overpressuring.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Protection against accidental overpressuring. 192.195 Section 192.195 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE... Pipeline Components § 192.195 Protection against accidental overpressuring. (a) General requirements...

  3. Visualization of radiation-induced cell cycle-associated events in tumor cells expressing the fusion protein of Azami Green and the destruction box of human Geminin

    SciTech Connect

    Ishikawa, Mayuko; Ogihara, Yusuke; Miura, Masahiko

    2009-11-20

    Ionizing radiation (IR) influences cell cycle-associated events in tumor cells. We expressed the fusion protein of Azami Green (AG) and the destruction box plus nuclear localization signal of human Geminin, an inhibitor of DNA replication licensing factor, in oral tumor cells. This approach allowed us to visualize G2 arrest in living cells following irradiation. The combination of time-lapse imaging analysis allowed us to observe the nuclear envelope break down (NEBD) at early M phase, and disappearance of fluorescence (DF) at the end of M phase. The duration from NEBD to DF was not much affected in irradiated cells; however, most of daughter cells harbored double-strand breaks. Complete DF was also observed in cells exhibiting abnormal mitosis or cytokinesis. We conclude that the fluorescent Geminin probe could function as a stable cell cycle indicator irrespective of genome integrity.

  4. Propulsion system ignition overpressure for the Space Shuttle

    NASA Technical Reports Server (NTRS)

    Ryan, R. S.; Jones, J. H.; Guest, S. H.; Struck, H. G.; Rheinfurth, M. H.; Verferaime, V. S.

    1981-01-01

    Liquid and solid rocket motor propulsion systems create an overpressure wave during ignition, caused by the accelerating gas particles pushing against or displacing the air contained in the launch pad or launch facility and by the afterburning of the fuel-rich gases. This wave behaves as a blast or shock wave characterized by a positive triangular-shaped first pulse and a negative half-sine wave second pulse. The pulse travels up the space vehicle and has the potential of either overloading individual elements or exciting overall vehicle dynamics. The latter effect results from the phasing difference of the wave from one side of the vehicle to the other. This overpressure phasing, or delta P environment, because of its frequency content as well as amplitude, becomes a design driver for certain panels (e.g., thermal shields) and payloads for the Space Shuttle. The history of overpressure effects on the Space Shuttle, the basic overpressure phenomenon, Space Shuttle overpressure environment, scale model overpressure testing, and techniques for suppressing the overpressure environments are considered.

  5. Ignition overpressure study from solid rocket motor firings

    NASA Technical Reports Server (NTRS)

    Counter, Douglas D.

    1987-01-01

    The objective was to investigate, through experimental means, the basic mechanisms influencing ignition overpressure and to determine ways to suppress ignition overpressure. Ignition overpressure was studied using solid rocket motors with geometry scaled at 1 percent of the Shuttle's Solid Rocket Boosters. Both water injection and aerosol foam were examined as a mean of reducing ignition overpressure. The results of the water injection tests indicate that a relatively small amount of water is sufficient to provide significant suppression. Of the flow rates tested, the lower water injection flow rates provided the best reduction of the ignition overpressure wave. Also, the test results show there is an optimum water flow rate range that provides the best suppression, and as this range is exceeded the effectiveness of water to reduce ignition overpressure is decreased. Aerosol foam provided very little reduction of ignition overpressure, but only small volumes of foam were used and further testing is necessary to determine its total effectiveness as a means of suppression.

  6. Record of source-generated overpressures, Venezuela

    SciTech Connect

    Vrolijk, P.J.; Pottorf, R.J.; Maze, W.B. )

    1996-01-01

    Fluid pressures affect migration of oil, gas, and water in continental margins. Burial and thermal history models describe the degree to which indercompaction or thermal expansion of fluids contribute to fluid pressure histories, but it is more difficult to evaluate how source-terms, such as oil yield or mineral dehydration reactions, impact paleo-fluid pressures. In this study, we document how a thick, maturing source rock helped create near-lithostatic fluid pressures that generated overpressures in reservoir rocks. We analyzed abundant oil-filled and rare aqueous fluid inclusions in calcite-filled fractures in the La Luna Fm. source rock and in the underlying Cogollo Gp. carbonate reservoir in the W. Maracaibo Basin, Venezuela. Homogenization temperatures (Th) of oil-filled inclusions range from 25-42[degrees]C in the La Luna Fm. and from 25-105[degrees]C in the Cogollo Gp., and associated gravities (determined from fluorescence properties) range from 28-43[degrees]API and 17-45[degrees]API, respectively. Integration of Th with the burial and thermal history of the sampled horizons leads to the conclusion that fractures in the La Luna Fm. formed under near-lithostatic fluid pressure conditions in the presence of a gas-charged oil. The values from fractures in the Cogollo Gp. are higher than in the La Luna Fm and become more variable with increasing depth below La Luna. We interpret those fractures to have formed under lower fluid pressure conditions and/or with a less gas-charged oil than for La Luna. This interpretation of the distribution of paleo-fluid pressures is supported by the observation of modern inverted fluid pressure gradients between upper and lower Cogollo Gp. reservoirs. Thus late expulsion of a gas-charged oil created near-lithostatic fluid pressures in the La Luna Fm. source rock, and those fluid pressures bled downward through fractures into the adjoining reservoir rocks, contributing to the overpressures we observe today.

  7. Record of source-generated overpressures, Venezuela

    SciTech Connect

    Vrolijk, P.J.; Pottorf, R.J.; Maze, W.B.

    1996-12-31

    Fluid pressures affect migration of oil, gas, and water in continental margins. Burial and thermal history models describe the degree to which indercompaction or thermal expansion of fluids contribute to fluid pressure histories, but it is more difficult to evaluate how source-terms, such as oil yield or mineral dehydration reactions, impact paleo-fluid pressures. In this study, we document how a thick, maturing source rock helped create near-lithostatic fluid pressures that generated overpressures in reservoir rocks. We analyzed abundant oil-filled and rare aqueous fluid inclusions in calcite-filled fractures in the La Luna Fm. source rock and in the underlying Cogollo Gp. carbonate reservoir in the W. Maracaibo Basin, Venezuela. Homogenization temperatures (Th) of oil-filled inclusions range from 25-42{degrees}C in the La Luna Fm. and from 25-105{degrees}C in the Cogollo Gp., and associated gravities (determined from fluorescence properties) range from 28-43{degrees}API and 17-45{degrees}API, respectively. Integration of Th with the burial and thermal history of the sampled horizons leads to the conclusion that fractures in the La Luna Fm. formed under near-lithostatic fluid pressure conditions in the presence of a gas-charged oil. The values from fractures in the Cogollo Gp. are higher than in the La Luna Fm and become more variable with increasing depth below La Luna. We interpret those fractures to have formed under lower fluid pressure conditions and/or with a less gas-charged oil than for La Luna. This interpretation of the distribution of paleo-fluid pressures is supported by the observation of modern inverted fluid pressure gradients between upper and lower Cogollo Gp. reservoirs. Thus late expulsion of a gas-charged oil created near-lithostatic fluid pressures in the La Luna Fm. source rock, and those fluid pressures bled downward through fractures into the adjoining reservoir rocks, contributing to the overpressures we observe today.

  8. Elastic-plastic response charts for nuclear overpressures. Final report

    SciTech Connect

    Guice, L.K.; Kiger, S.A.

    1984-06-01

    The single-degree-of-freedom equation of motion for an elastic-plastic system with forcing functions that are representative of nuclear weapon simulations is nondimensionalized and solved. Numerical solutions are calculated by the Newmark Beta method, and response charts incorporating nondimensionalized structural and loading parameters for the Speicher-Brode nuclear pressure history description are provided. A computer code is presented for solving the elastic-plastic problem for Speicher-Brode overpressure as well as triangular-shaped overpressures.

  9. Overpressure and seals in the North Sea - a model approach

    SciTech Connect

    Cavanagh, A.G.; Couples, D.D.; Haszeldine, R.S.

    1996-12-31

    Overpressure prediction in the North Sea is complicated by fault seal assumptions. The computer code, BasinMod-2D, is used to simulate overpressure for a small-scale case study, the Puffin structure, located on the western flank of the Central Graben. This area is characterized by tilted fault blocks and syn-rift sedimentation of Upper Jurassic Fulmar sandstones with a post-rift cover of Cretaceous chalk and Tertiary mudstones. The model, a 10 km W-E section based on published seismic data, is tied to detailed well stratigraphy in 29/10 -2 with pressure data from RFT and mudweight. The model fails to replicate observed overpressure data. The simulated overpressure is 20 MPa lower than the measured pressure of 85 MPa in the Puffin structure. The model fails to simulate hydrocarbon accumulation in the Fulmar sandstone reservoir, in contradiction to the observed bitumen indication of paleoaccumulation. The model also raises important questions as to the validity of uncalibrated parameter manipulation as a means of forward modelling fault seal, with specific reference to shale permeability. We contend that these failures are not due to model limitations, but are the result of the size-scale of this case study. The inference is that overpressure and hydrocarbon creation and transmission is on a size scale fault seal at one time can leak hydrocarbons at another time. We consider that the drive for this comes from pressure increase during hydrocarbon generation in the deep kitchen.

  10. Overpressure and seals in the North Sea - a model approach

    SciTech Connect

    Cavanagh, A.G.; Couples, D.D.; Haszeldine, R.S. )

    1996-01-01

    Overpressure prediction in the North Sea is complicated by fault seal assumptions. The computer code, BasinMod-2D, is used to simulate overpressure for a small-scale case study, the Puffin structure, located on the western flank of the Central Graben. This area is characterized by tilted fault blocks and syn-rift sedimentation of Upper Jurassic Fulmar sandstones with a post-rift cover of Cretaceous chalk and Tertiary mudstones. The model, a 10 km W-E section based on published seismic data, is tied to detailed well stratigraphy in 29/10 -2 with pressure data from RFT and mudweight. The model fails to replicate observed overpressure data. The simulated overpressure is 20 MPa lower than the measured pressure of 85 MPa in the Puffin structure. The model fails to simulate hydrocarbon accumulation in the Fulmar sandstone reservoir, in contradiction to the observed bitumen indication of paleoaccumulation. The model also raises important questions as to the validity of uncalibrated parameter manipulation as a means of forward modelling fault seal, with specific reference to shale permeability. We contend that these failures are not due to model limitations, but are the result of the size-scale of this case study. The inference is that overpressure and hydrocarbon creation and transmission is on a size scale fault seal at one time can leak hydrocarbons at another time. We consider that the drive for this comes from pressure increase during hydrocarbon generation in the deep kitchen.

  11. Pericardial tamponade consequent to a dynamite explosion: blast overpressure injury without penetrating trauma.

    PubMed

    Ozer, Orhan; Sari, Ibrahim; Davutoglu, Vedat; Yildirim, Cuma

    2009-01-01

    Acute cardiac tamponade is a life-threatening emergency that requires prompt treatment by either percutaneous or surgical pericardiocentesis. It may occur after penetrating or blunt chest trauma. We report a case of pericardial tamponade in the absence of penetrating trauma, due to blast overpressure injury after a dynamite explosion-which has not, to our knowledge, been reported before. Physicians should be aware of the possibility of pericardial tamponade in victims of barotraumatic events such as dynamite or bomb explosions, even in the absence of penetrating trauma. Cardiac tamponade, although life-threatening, is easy to treat when recognized.

  12. Overpressure proof testing of large infrared windows for aircraft applications

    NASA Astrophysics Data System (ADS)

    Pruszynski, Charles J.

    1991-10-01

    Many commonly used infrared window materials, such as zinc sulfide and zinc selenide, are subject to structural failure due to stress-corrosion induced cracking. This failure mechanism is of critical importance in applications in which the window experiences high static pressure loading for prolonged periods in humid atmospheres, conditions typical of airborne optical windows. The most effective means of screening windows against failure due to this mechanism is by use of overpressure proof testing. In this paper, the design of overpressure proof tests for large airborne infrared windows is discussed. The underlying physical phenomena and governing mathematical relationships are presented. A hypothetical proof test design for a large infrared window to be employed in a man-rated aircraft is developed to illustrate the application of the analytical methodology. Practical considerations in the execution of large infrared window overpressure proof tests are also discussed.

  13. Ares I Scale Model Acoustic Test Overpressure Results

    NASA Technical Reports Server (NTRS)

    Casiano, M. J.; Alvord, D. A.; McDaniels, D. M.

    2011-01-01

    A summary of the overpressure environment from the 5% Ares I Scale Model Acoustic Test (ASMAT) and the implications to the full-scale Ares I are presented in this Technical Memorandum. These include the scaled environment that would be used for assessing the full-scale Ares I configuration, observations, and team recommendations. The ignition transient is first characterized and described, the overpressure suppression system configuration is then examined, and the final environment characteristics are detailed. The recommendation for Ares I is to keep the space shuttle heritage ignition overpressure (IOP) suppression system (below-deck IOP water in the launch mount and mobile launcher and also the crest water on the main flame deflector) and the water bags.

  14. Data destruction.

    PubMed

    Bergren, Martha Dewey

    2005-08-01

    School nurses are caretakers of a vast amount of sensitive student and family health information. In schools, older computer hardware that previously stored education records is recycled for less demanding student and employee functions. Sensitive data must be adequately erased before electronic storage devices are reassigned or are discarded. State and federal laws must be considered when permanently destroying personally identifiable student information. To fulfill their ethical and legal responsibilities, school nurses must be aware of record retention and data destruction policies and procedures for both paper and electronic records.

  15. Fluid overpressures and strength of the sedimentary upper crust

    NASA Astrophysics Data System (ADS)

    Suppe, John

    2014-12-01

    The classic crustal strength-depth profile based on rock mechanics predicts a brittle strength σ1 -σ3 = κ(ρbar gz -Pf) that increases linearly with depth as a consequence of [1] the intrinsic brittle pressure dependence κ plus [2] an assumption of hydrostatic pore-fluid pressure, Pf = ρwgz. Many deep borehole stress data agree with a critical state of failure of this form. In contrast, fluid pressures greater than hydrostatic ρbar gz >Pf >ρw gz are normally observed in clastic continental margins and shale-rich mountain belts. Therefore we explore the predicted shapes of strength-depth profiles using data from overpressured regions, especially those dominated by the widespread disequilibrium-compaction mechanism, in which fluid pressures are hydrostatic above the fluid-retention depth zFRD and overpressured below, increasing parallel to the lithostatic gradient ρbar gz . Both brittle crustal strength and frictional fault strength below the zFRD must be constant with depth because effective stress (ρbar gz -Pf) is constant, in contrast with the classic linearly increasing profile. Borehole stress and fluid-pressure measurements in several overpressured deforming continental margins agree with this constant-strength prediction, with the same pressure-dependence κ as the overlying hydrostatic strata. The role of zFRD in critical-taper wedge mechanics and jointing is illustrated. The constant-strength approximation is more appropriate for overpressured crust than classic linearly increasing models.

  16. Rocket Launch-Induced Vibration and Ignition Overpressure Response

    NASA Technical Reports Server (NTRS)

    Caimi, Raoul; Margasahayam, Ravi; Nayfeh, Jamal; Thompson, Karen (Technical Monitor)

    2001-01-01

    Rocket-induced vibration and ignition overpressure response environments are predicted in the low-frequency (5 to 200 hertz) range. The predictions are necessary to evaluate their impact on critical components, structures, and facilities in the immediate vicinity of the rocket launch pad.

  17. Rocket Launch-Induced Vibration and Ignition Overpressure Response

    NASA Technical Reports Server (NTRS)

    Caimi, Raoul E.; Margashayam, Ravi N.; Nayfeh, Jamal F.; Thompson, Karen (Technical Monitor)

    2001-01-01

    Rocket-induced vibration and ignition overpressure response environments are predicted in the low-frequency (5 to 200 hertz) range. The predictions are necessary to evaluate their impact on critical components, structures, and facilities in the immediate vicinity of the rocket launch pad.

  18. Prediction of Launch Vehicle Ignition Overpressure and Liftoff Acoustics

    NASA Technical Reports Server (NTRS)

    Casiano, Matthew

    2009-01-01

    The LAIOP (Launch Vehicle Ignition Overpressure and Liftoff Acoustic Environments) program predicts the external pressure environment generated during liftoff for a large variety of rocket types. These environments include ignition overpressure, produced by the rapid acceleration of exhaust gases during rocket-engine start transient, and launch acoustics, produced by turbulence in the rocket plume. The ignition overpressure predictions are time-based, and the launch acoustic predictions are frequency-based. Additionally, the software can predict ignition overpressure mitigation, using water-spray injection into the rocket exhaust stream, for a limited number of configurations. The framework developed for these predictions is extensive, though some options require additional relevant data and development time. Once these options are enabled, the already extensively capable code will be further enhanced. The rockets, or launch vehicles, can either be elliptically or cylindrically shaped, and up to eight strap-on structures (boosters or tanks) are allowed. Up to four engines are allowed for the core launch vehicle, which can be of two different types. Also, two different sizes of strap-on structures can be used, and two different types of booster engines are allowed. Both tabular and graphical presentations of the predicted environments at the selected locations can be reviewed by the user. The output includes summaries of rocket-engine operation, ignition overpressure time histories, and one-third octave sound pressure spectra of the predicted launch acoustics. Also, documentation is available to the user to help him or her understand the various aspects of the graphical user interface and the required input parameters.

  19. Overpressure Prediction From Seismic Data: Implications on Drilling Safety

    NASA Astrophysics Data System (ADS)

    Osinowo, O. O.; Oladunjoye, M. A.; Olayinka, A. I.

    2007-12-01

    High rate of sediment influx into the Niger Delta via river Niger coupled with high rate of basin subsidence, very thick clayey members of Agbada and Akata Formations as well as prevailing presence of growth faults had been identified as the main factors responsible for overpressure generation and preservation in the Niger Delta basin. Analysis of porosity dependent parameters such as interval transit times and interval velocities derived from the seismic records of a field in the Western Niger Delta revealed the presence of overpressured formation at depth of 8670 feet, which is the top of the overpressured zone. The plot of interval transit times against depth gave a positive deflection from normal at the region of overpressure while interval velocity plot gave negative deflection; the ratio of this deviation in both cases is as high as 1.52. Pressure gradient in the upper, normally pressured part of the field was determined to be 0.465 psi/ft., which is within the established normal pressure gradient range in Niger Delta, while the abnormal formation pressure gradient in the overpressured region was determined to be 0.96 psi/ft., and this is also within the published abnormal pressure gradient range of 0.71 to 1.1 psi/ft. in Niger Delta. Formation fracture pressure gradients were determined from the formation pressure information to be 0.66psi/ft. in the upper part of the field and 1.2psi/ft. in the overpressured horizon. Mud weight window (MWW); mud density range necessary to prevent formation kick without initiating hydraulic fracturing was determined to be 10.2 to 12.5lbm/gal in the upper part of the field and 22.1 to 22.63lbm/gal in the overpressured horizon. MWW is indispensable for the selection of the mud pump type, capacity, pumping rate and mud densities at different formation pressure regimes. Overpressure prediction is also requisite for drilling program design, casing design as well as rig capacity choice before spudding. It is necessary to reduce

  20. Overpressure and Its Relation to Petroleum Accumulation in Southern Edge of Junggar Basin

    NASA Astrophysics Data System (ADS)

    Zhao, G.

    2014-12-01

    Abstract: Measured formation pressure, well- log and mud weight data show that there are overpressures in the southern edge of Junggar basin. Vertically, overpressure distribution is not direct ly related to the burial depth, it is mainly controlled by stratigraphic horizons, especially the lower Tertiary Anjihaihe Formation has the most evident control over the overpressures. Horizontally, overpressure occur in the 3 structural belts in southern edge of the basin, but there are differences in the east and in the west : in the eastern part overpressures occur in the Anjihaihe Formation only, while in the western part, they occur not only in the Anjihaihe Formation, but also in the Shawan and Ziniguanzi Formation. Analyzing the relationship between the well test data and overpressures in the southern edge of Junggar basin, it can be found that the distribution of oil and gas reservoirs are closely related to the overpressures. Being affected by faulting, and due to the differences in mechanism of relationship between overpressures and preservation of oil and gas reservoirs, the distribution of overpressures and oil and gas reservoirs cannot be corresponding to one another. As a whole, however, oil and gas would be ready to be reservoired in the normally pressured zone below the moderately abnormal pressured or overpressures zone, which would, therefore, be the favorable target of petroleum exploration; while the overpressured zone with relatively high formation pressure coefficient is unfavorable for oil/ gas reservoiring.

  1. Probability analysis of MCO over-pressurization during staging

    SciTech Connect

    Pajunen, A.L.

    1997-06-05

    The purpose of this calculation is to determine the probability of Multi-Canister Overpacks (MCOs) over-pressurizing during staging at the Canister Storage Building (CSB). Pressurization of an MCO during staging is dependent upon changes to the MCO gas temperature and the build-up of reaction products during the staging period. These effects are predominantly limited by the amount of water that remains in the MCO following cold vacuum drying that is available for reaction during staging conditions. Because of the potential for increased pressure within an MCO, provisions for a filtered pressure relief valve and rupture disk have been incorporated into the MCO design. This calculation provides an estimate of the frequency that an MCO will contain enough water to pressurize beyond the limits of these design features. The results of this calculation will be used in support of further safety analyses and operational planning efforts. Under the bounding steady state CSB condition assumed for this analysis, an MCO must contain less than 1.6 kg (3.7 lbm) of water available for reaction to preclude actuation of the pressure relief valve at 100 psid. To preclude actuation of the MCO rupture disk at 150 psid, an MCO must contain less than 2.5 kg (5.5 lbm) of water available for reaction. These limits are based on the assumption that hydrogen generated by uranium-water reactions is the sole source of gas produced within the MCO and that hydrates in fuel particulate are the primary source of water available for reactions during staging conditions. The results of this analysis conclude that the probability of the hydrate water content of an MCO exceeding 1.6 kg is 0.08 and the probability that it will exceed 2.5 kg is 0.01. This implies that approximately 32 of 400 staged MCOs may experience pressurization to the point where the pressure relief valve actuates. In the event that an MCO pressure relief valve fails to open, the probability is 1 in 100 that the MCO would experience

  2. Tensile overpressure compartments on low-angle thrust faults

    NASA Astrophysics Data System (ADS)

    Sibson, Richard H.

    2017-08-01

    Hydrothermal extension veins form by hydraulic fracturing under triaxial stress (principal compressive stresses, σ 1 > σ 2 > σ 3) when the pore-fluid pressure, P f, exceeds the least compressive stress by the rock's tensile strength. Such veins form perpendicular to σ 3, their incremental precipitation from hydrothermal fluid often reflected in `crack-seal' textures, demonstrating that the tensile overpressure state, σ 3' = ( σ 3 - P f) < 0, was repeatedly met. Systematic arrays of extension veins develop locally in both sub-metamorphic and metamorphic assemblages defining tensile overpressure compartments where at some time P f > σ 3. In compressional regimes ( σ v = σ 3), subhorizontal extension veins may develop over vertical intervals <1 km or so below low-permeability sealing horizons with tensile strengths 10 < T o < 20 MPa. This is borne out by natural vein arrays. For a low-angle thrust, the vertical interval where the tensile overpressure state obtains may continue down-dip over distances of several kilometres in some instances. The overpressure condition for hydraulic fracturing is comparable to that needed for frictional reshear of a thrust fault lying close to the maximum compression, σ 1. Under these circumstances, especially where the shear zone material has varying competence (tensile strength), affecting the failure mode, dilatant fault-fracture mesh structures may develop throughout a tabular rock volume. Evidence for the existence of fault-fracture meshes around low-angle thrusts comes from exhumed ancient structures and from active structures. In the case of megathrust ruptures along subduction interfaces, force balance analyses, lack of evidence for shear heating, and evidence of total shear stress release during earthquakes suggest the interfaces are extremely weak ( τ < 40 MPa), consistent with weakening by near-lithostatically overpressured fluids. Portions of the subduction interface, especially towards the down-dip termination of

  3. Explosion overpressure test series: General-Purpose Heat Source development: Safety Verification Test program

    SciTech Connect

    Cull, T.A.; George, T.G.; Pavone, D.

    1986-09-01

    The General-Purpose Heat Source (GPHS) is a modular, radioisotope heat source that will be used in radioisotope thermoelectric generators (RTGs) to supply electric power for space missions. The first two uses will be the NASA Galileo and the ESA Ulysses missions. The RTG for these missions will contain 18 GPHS modules, each of which contains four /sup 238/PuO/sub 2/-fueled clads and generates 250 W/sub (t)/. A series of Safety Verification Tests (SVTs) was conducted to assess the ability of the GPHS modules to contain the plutonia in accident environments. Because a launch pad or postlaunch explosion of the Space Transportation System vehicle (space shuttle) is a conceivable accident, the SVT plan included a series of tests that simulated the overpressure exposure the RTG and GPHS modules could experience in such an event. Results of these tests, in which we used depleted UO/sub 2/ as a fuel simulant, suggest that exposure to overpressures as high as 15.2 MPa (2200 psi), without subsequent impact, does not result in a release of fuel.

  4. Thermodynamically consistent model of brittle oil shales under overpressure

    NASA Astrophysics Data System (ADS)

    Izvekov, Oleg

    2016-04-01

    The concept of dual porosity is a common way for simulation of oil shale production. In the frame of this concept the porous fractured media is considered as superposition of two permeable continua with mass exchange. As a rule the concept doesn't take into account such as the well-known phenomenon as slip along natural fractures, overpressure in low permeability matrix and so on. Overpressure can lead to development of secondary fractures in low permeability matrix in the process of drilling and pressure reduction during production. In this work a new thermodynamically consistent model which generalizes the model of dual porosity is proposed. Particularities of the model are as follows. The set of natural fractures is considered as permeable continuum. Damage mechanics is applied to simulation of secondary fractures development in low permeability matrix. Slip along natural fractures is simulated in the frame of plasticity theory with Drucker-Prager criterion.

  5. Measurements of sonic-boom overpressures from Apollo space vehicles

    NASA Technical Reports Server (NTRS)

    Hilton, D. A.; Henderson, H. R.

    1974-01-01

    This paper presents representative results of sonic-boom overpressure data recorded during the launch and reentry of the Apollo 15 and 16 space vehicle systems. Comparisons are made between measured overpressures and those predicted using available theory. The measurements were obtained along the vehicle ground track at 68, 87, 92, 129, and 970 km downrange from the launch site during ascent, and at 9, 13, 55, 185, and 500 km from the splash-down point during reentry. Also included are tracings of the sonic-boom signatures along with a brief description of the launch and recovery test areas in which the measurements were obtained, the sonic-boom instrumentation deployment, flight profiles and operating conditions, and high-altitude weather information for the general measurement areas.

  6. Occupational overpressure exposure of breachers and military personnel

    NASA Astrophysics Data System (ADS)

    Kamimori, G. H.; Reilly, L. A.; LaValle, C. R.; Olaghere Da Silva, U. B.

    2017-08-01

    Military and law enforcement personnel may be routinely and repetitively exposed to low-level blast (LLB) overpressure during training and in operations. This repeated exposure has been associated with symptoms similar to that reported for sports concussion. This study reports LLB exposure for various military and law enforcement sources in operational training environments. Peak overpressure and impulse data are presented from indoor breaching, outdoor breaching, shotgun door breaching, small arms discharge, and mortar and artillery fire missions. Data were collected using the Black Box Biometrics (B3) Blast Gauge sensors. In all cases, sensors were attached to the operators and, where possible, also statically mounted to walls or other fixed structures. Peak overpressures from below 1 psi (7 kPa) to over 12 psi (83 kPa) were recorded; all values reported are uncorrected for incidence angle to the blast exposure source. The results of these studies indicate that the current minimum safe distance calculations are often inaccurate for both indoor and outdoor breaching scenarios as true environmental exposure can consistently exceed the 4 psi (28 kPa) incident safe threshold prescribed by U.S. Army doctrine. While ballistic (shotgun) door breaching and small arms firing only expose the operator to low peak exposure levels, the sheer number of rounds fired during training may result in an excessive cumulative exposure. Mortar and artillery crew members received significantly different overpressure and impulse exposures based on their position (job) relative to the weapon. As both the artillery and mortar crews commonly fire hundreds of rounds during a single training session they are also likely to receive high cumulative exposures. These studies serve to provide the research community with estimates for typical operator exposure across a range of operational scenarios or in the discharge of various weapons systems.

  7. Distribution and generation of the overpressure system, eastern Delaware Basin, western Texas and southern New Mexico

    SciTech Connect

    Luo, M.; Baker, M.R.; LeMone, D.V.

    1994-09-01

    Three subsurface pressure systems have been identified in the Delaware basin: an upper normal pressure system, a middle overpressure system, and a lower normal pressure system. The overpressure system occurs in the eastern Delaware basin, covering six Texas and New Mexico counties. The depth of the overpressure system ranges from 3100 to 5400 m. The normal fluid pressure gradient is 0.0103 MPa/m in the eastern Delaware basin. The highest overpressure gradient, however, approaches 0.02 MPa/m, which is close to the lithostatic gradient of 0.0231 MPa/m. An area of excess pressure occurs within the system where the highest excess pressure reaches 60 MPa. Local underpressured areas due to production are found in the lower normal pressure system in the War-Wink field area. Overpressure in the eastern Delaware basin is mainly associated with Mississippian, Pennsylvanian, and Permian (Wolfcampian) shale sequences, which also are major source rocks in the basin. Corrected bottom-hole temperature measurements indicate that the geothermal gradient within the overpressure zone is 25.1{degrees}C/km, which is higher than the basin`s average geothermal gradient of 21{degrees}C/km. Temperatures at the top and bottom of the overpressure system are about 80 and 115{degrees}C, respectively. The oil window in the War-Wink field is coincident with the overpressure system, which implies that hydrocarbon generation and migration are active in the overpressure system. A two-stage overpressure model is proposed. Hydrocarbon maturation combined with mechanical compaction disequilibrium and clay dehydration are the initial causes for overpressure generation due to an abnormal increase of fluid volume and pore space. Subsequently, the increase in temperature due to a decrease of thermal conductivity and fluid migration within the preexisting overpressure system would reinforce further overpressuring due to the fluid thermal expansion.

  8. Experimental magnesium depletion in adult rabbits caused by blast overpressure.

    PubMed

    Cernak, I; Radosevic, P; Malicevic, Z; Savic, J

    1995-09-01

    The complex pressure wave (blast) generated by some explosions causes pulmonary pathological changes which resemble the histological findings of the adult respiratory distress syndrome (ARDS). The development of indirect neurotrauma following experimental pulmonary blast injury has been shown previously. The purpose of this study was to evaluate lung and brainstem total tissue magnesium concentrations in adult rabbits following pulmonary blast injury. In order to assess the interrelationship between magnesium and other secondary injury factors, total calcium and high energy phosphate (phosphocreatine, PCr; adenosine triphosphate, ATP) contents were simultaneously measured. Twenty adult male rabbits were divided into two groups. Group C (n = 10) served as control, while group B (n = 10) was subjected to a focused blast wave, generated in laboratory conditions using an air-driven shock tube. Moderate pulmonary blast injury was verified by histological examination in group B. Total tissue magnesium and calcium contents were measured by atomic absorption spectrophotometry in the lungs and brainstem of adult rabbits 30 min following blast overpressure and in their uninjured controls. Simultaneously, PCr and ATP contents were measured by fluorimetric enzymatic analyses in same structures. Lung and brainstem water contents were determined by wet weight to dry weight ratio. Blast overpressure to the lungs induced significant magnesium depletion, increased calcium and decreased the Mg/Ca ratio in lung tissue of injured animals. Increases in water content and PCr/ATP ratio were also observed. Significant correlations between these Mg/Ca and PCr/ATP and between Mg and ATP parameters confirmed the functional relationship between magnesium depletion and impaired bioenergetic state in indirect neurotrauma in adult rabbits through blast overpressure.

  9. Cleaning validation procedure eased by using overpressured layer chromatography.

    PubMed

    Katona, Z; Vincze, L; Végh, Z; Trompler, A; Ferenczi-Fodor, K

    2000-03-01

    In the manufacturing plants of many pharmaceutical companies the reaction apparatus is suitable to produce different active pharmaceutical ingredients. After completing the production of a compound the equipment should be cleaned in order to avoid the cross contamination in the next lot of the other products. In the authors' laboratory several chromatographic methods were introduced to measure the amount of the residual substances remaining on the surface of the apparatus after the cleaning procedure. A sensitive and fairly rapid overpressured layer chromatographic (OPLC) procedure--suitable to separate and control five steroid hormone compounds (allylestrenol, estradiol, ethynodiol diacetate, levonorgestel, norethisterone) produced in the same equipment at different times--was developed and validated.

  10. Effects of blast overpressure on the ear: case reports.

    PubMed

    Chandler, D W; Edmond, C V

    1997-04-01

    The case histories of five patients who experienced blast overpressure in excess of 200-dB peak pressure level are presented. Despite the significance of the sound pressure levels received in a military training accident and the severe injuries that resulted from the blast, these individuals experienced substantial improvement of hearing 1 year later. Undoubtedly, successful surgical intervention and medical management were the primary contributors to the restoration of hearing. Audiometric data are presented documenting hearing status within 2 to 3 weeks postinjury and following final surgical remediation of the resulting middle ear damage. A review of these cases offers insight into the possible prognosis of patients with similar injuries.

  11. [Local overpressure treatment reduces vestibular symptoms in patients with Menière's disease--secondary publication. A clinically randomised multicenter double-blind placebo-controlled study].

    PubMed

    Thomsen, Jens C; Sass, Kornel; Odkvist, Lars; Arlinger, Stig

    2006-01-23

    This investigation was performed to evaluate the efficacy of a new device, the Méniètt, in the treatment of Ménière's disease. The device delivers pressure pulses to the middle ear through a ventilating tube in the tympanic membrane. These pressure changes are conveyed to the inner ear, reducing the endolymphatic hydrops. The device is significantly effective in reducing the vestibular symptoms, as compared with the placebo device. Local overpressure treatment is a novel treatment that is non-invasive, non-destructive and safe. It should be offered to patients before more invasive surgical modalities are suggested.

  12. Explosion impacts during transport of hazardous cargo: GIS-based characterization of overpressure impacts and delineation of flammable zones for ammonia.

    PubMed

    Inanloo, Bahareh; Tansel, Berrin

    2015-06-01

    The aim of this research was to investigate accidental releases of ammonia followed by an en-route incident in an attempt to further predict the consequences of hazardous cargo accidents. The air dispersion model Areal Locations of Hazardous Atmospheres (ALOHA) was employed to track the probable outcomes of a hazardous material release of a tanker truck under different explosion scenarios. The significance of identification of the flammable zones was taken into consideration; in case the flammable vapor causes an explosion. The impacted areas and the severity of the probable destructions were evaluated for an explosion by considering the overpressure waves. ALOHA in conjunction with ArcGIS was used to delineate the flammable and overpressure impact zones for different scenarios. Based on the results, flammable fumes were formed in oval shapes having a chief axis along the wind direction at the time of release. The expansions of the impact areas under the overpressure value which can lead to property damage for 2 and 20 tons releases, under very stable and unstable atmospheric conditions were estimated to be around 1708, 1206; 3742, 3527 feet, respectively, toward the wind direction. A sensitivity analysis was done to assess the significance of wind speed on the impact zones. The insight provided by this study can be utilized by decision makers in transportation of hazardous materials as a guide for possible rerouting, rescheduling, or limiting the quantity of hazardous cargo to reduce the possible impacts after hazardous cargo accidents during transport. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Membrane characteristics for biological blast overpressure testing using blast simulators.

    PubMed

    Alphonse, Vanessa D; Siva Sai Sujith Sajja, Venkata; Kemper, Andrew R; Rizel, Dave V; Duma, Stefan M; VandeVord, Pamela J

    2014-01-01

    Blast simulators often use passive-rupture membranes to generate shock waves similar to free-field blasts. The purpose of this study was to compare rupture patterns and pressure traces of three distinct membrane materials for biological and biomechanical blast studies. An Advanced Blast Simulator (ABS) located at the Center for Injury Biomechanics at Virginia Tech was used to test membrane characteristics. Acetate, Mylar, and aluminum sheets with different thicknesses were used to obtain pressures between 70–210 kPa. Static pressure was measured inside the tube at the test section using piezoelectric pressure sensors. Peak overpressure, positive duration, and positive impulse were calculated for each test. Rupture patterns and characteristic pressure traces were unique to each membrane type and thickness. Shock wave speed ranged between 1.2-1.8 Mach for static overpressures of 70–210 kPa. Acetate membranes fragmented sending pieces down the tube, but produced ideal (Friedlander) pressure traces. Mylar membranes bulged without fragmenting, but produced less-than-ideal pressure traces. Aluminum membranes did not fragment and produced ideal pressure traces. However, the cost of manufacturing and characterizing aluminum membranes should be considered during membrane selection. This study illustrates the advantages and disadvantages of using Mylar, acetate, and aluminum for passive rupture membranes for blast simulators.

  14. Legal Weapons of Mass Destruction Consequence Management

    DTIC Science & Technology

    2002-05-01

    LEGAL WEAPONS OF MASS DESTRUCTION CONSEQUENCE MANAGEMENT SEMINAR REPORT Defense Threat Reduction Agency Advanced Systems ...guidance documents pertinent to WMD CM ; • Contribute to the development of a Federal Legal Reference Deskbook for WMD consequence management . The...of medical responders during a Weapons of Mass Destruction (WMD)–Consequence Management ( CM ) event. Use of the Military Posse Comitatus

  15. Uncertainty quantification of overpressure buildup through inverse modeling of compaction processes in sedimentary basins

    NASA Astrophysics Data System (ADS)

    Colombo, Ivo; Porta, Giovanni M.; Ruffo, Paolo; Guadagnini, Alberto

    2016-11-01

    This study illustrates a procedure conducive to a preliminary risk analysis of overpressure development in sedimentary basins characterized by alternating depositional events of sandstone and shale layers. The approach rests on two key elements: (1) forward modeling of fluid flow and compaction, and (2) application of a model-complexity reduction technique based on a generalized polynomial chaos expansion (gPCE). The forward model considers a one-dimensional vertical compaction processes. The gPCE model is then used in an inverse modeling context to obtain efficient model parameter estimation and uncertainty quantification. The methodology is applied to two field settings considered in previous literature works, i.e. the Venture Field (Scotian Shelf, Canada) and the Navarin Basin (Bering Sea, Alaska, USA), relying on available porosity and pressure information for model calibration. It is found that the best result is obtained when porosity and pressure data are considered jointly in the model calibration procedure. Uncertainty propagation from unknown input parameters to model outputs, such as pore pressure vertical distribution, is investigated and quantified. This modeling strategy enables one to quantify the relative importance of key phenomena governing the feedback between sediment compaction and fluid flow processes and driving the buildup of fluid overpressure in stratified sedimentary basins characterized by the presence of low-permeability layers. The results here illustrated (1) allow for diagnosis of the critical role played by the parameters of quantitative formulations linking porosity and permeability in compacted shales and (2) provide an explicit and detailed quantification of the effects of their uncertainty in field settings.

  16. Uncertainty quantification of overpressure buildup through inverse modeling of compaction processes in sedimentary basins

    NASA Astrophysics Data System (ADS)

    Colombo, Ivo; Porta, Giovanni M.; Ruffo, Paolo; Guadagnini, Alberto

    2017-03-01

    This study illustrates a procedure conducive to a preliminary risk analysis of overpressure development in sedimentary basins characterized by alternating depositional events of sandstone and shale layers. The approach rests on two key elements: (1) forward modeling of fluid flow and compaction, and (2) application of a model-complexity reduction technique based on a generalized polynomial chaos expansion (gPCE). The forward model considers a one-dimensional vertical compaction processes. The gPCE model is then used in an inverse modeling context to obtain efficient model parameter estimation and uncertainty quantification. The methodology is applied to two field settings considered in previous literature works, i.e. the Venture Field (Scotian Shelf, Canada) and the Navarin Basin (Bering Sea, Alaska, USA), relying on available porosity and pressure information for model calibration. It is found that the best result is obtained when porosity and pressure data are considered jointly in the model calibration procedure. Uncertainty propagation from unknown input parameters to model outputs, such as pore pressure vertical distribution, is investigated and quantified. This modeling strategy enables one to quantify the relative importance of key phenomena governing the feedback between sediment compaction and fluid flow processes and driving the buildup of fluid overpressure in stratified sedimentary basins characterized by the presence of low-permeability layers. The results here illustrated (1) allow for diagnosis of the critical role played by the parameters of quantitative formulations linking porosity and permeability in compacted shales and (2) provide an explicit and detailed quantification of the effects of their uncertainty in field settings.

  17. 33 CFR 154.2203 - Facility requirements for barge vapor overpressure and vacuum protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... vapor overpressure and vacuum protection. 154.2203 Section 154.2203 Navigation and Navigable Waters... Installation § 154.2203 Facility requirements for barge vapor overpressure and vacuum protection. In this... valve or a vacuum relief valve apply only to facilities collecting vapors of flammable, combustible,...

  18. 33 CFR 154.2103 - Facility requirements for vessel vapor overpressure and vacuum protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... vapor overpressure and vacuum protection. 154.2103 Section 154.2103 Navigation and Navigable Waters... § 154.2103 Facility requirements for vessel vapor overpressure and vacuum protection. In this section... valve or a vacuum relief valve apply only to facilities collecting vapors of flammable, combustible,...

  19. 46 CFR 39.2011 - Vapor overpressure and vacuum protection-TB/ALL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Vapor overpressure and vacuum protection-TB/ALL. 39.2011 Section 39.2011 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS VAPOR CONTROL SYSTEMS Equipment and Installation § 39.2011 Vapor overpressure and vacuum protection—TB/ALL. (a) The cargo tank...

  20. 46 CFR 39.2011 - Vapor overpressure and vacuum protection-TB/ALL.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Vapor overpressure and vacuum protection-TB/ALL. 39.2011 Section 39.2011 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS VAPOR CONTROL SYSTEMS Equipment and Installation § 39.2011 Vapor overpressure and vacuum protection—TB/ALL. (a) The cargo tank...

  1. 49 CFR 195.428 - Overpressure safety devices and overfill protection systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Overpressure safety devices and overfill protection systems. 195.428 Section 195.428 Transportation Other Regulations Relating to Transportation... Overpressure safety devices and overfill protection systems. (a) Except as provided in paragraph (b) of this...

  2. 49 CFR 195.428 - Overpressure safety devices and overfill protection systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Overpressure safety devices and overfill protection systems. 195.428 Section 195.428 Transportation Other Regulations Relating to Transportation... Overpressure safety devices and overfill protection systems. (a) Except as provided in paragraph (b) of this...

  3. 49 CFR 195.428 - Overpressure safety devices and overfill protection systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Overpressure safety devices and overfill protection systems. 195.428 Section 195.428 Transportation Other Regulations Relating to Transportation... Overpressure safety devices and overfill protection systems. (a) Except as provided in paragraph (b) of this...

  4. Experimental study of near-field entrainment of moderately overpressured jets

    USGS Publications Warehouse

    Solovitz, S.A.; Mastin, L.G.; Saffaraval, F.

    2011-01-01

    Particle image velocimetry (PIV) experiments have been conducted to study the velocity flow fields in the developing flow region of high-speed jets. These velocity distributions were examined to determine the entrained mass flow over a range of geometric and flow conditions, including overpressured cases up to an overpressure ratio of 2.83. In the region near the jet exit, all measured flows exhibited the same entrainment up until the location of the first shock when overpressured. Beyond this location, the entrainment was reduced with increasing overpressure ratio, falling to approximately 60 of the magnitudes seen when subsonic. Since entrainment ratios based on lower speed, subsonic results are typically used in one-dimensional volcanological models of plume development, the current analytical methods will underestimate the likelihood of column collapse. In addition, the concept of the entrainment ratio normalization is examined in detail, as several key assumptions in this methodology do not apply when overpressured.

  5. Craton destruction and related resources

    NASA Astrophysics Data System (ADS)

    Zhu, Rixiang; Zhang, Hongfu; Zhu, Guang; Meng, Qingren; Fan, Hongrui; Yang, Jinhui; Wu, Fuyuan; Zhang, Zhiyong; Zheng, Tianyu

    2017-02-01

    Craton destruction is a dynamic event that plays an important role in Earth's evolution. Based on comprehensive observations of many studies on the North China Craton (NCC) and correlations with the evolution histories of other cratons around the world, craton destruction has be defined as a geological process that results in the total loss of craton stability due to changes in the physical and chemical properties of the involved craton. The mechanisms responsible for craton destruction would be as the follows: (1) oceanic plate subduction; (2) rollback and retreat of a subducting oceanic plate; (3) stagnation and dehydration of a subducting plate in the mantle transition zone; (4) melting of the mantle above the mantle transition zone caused by dehydration of a stagnant slab; (5) non-steady flow in the upper mantle induced by melting, and/or (6) changes in the nature of the lithospheric mantle and consequent craton destruction caused by non-steady flow. Oceanic plate subduction itself does not result in craton destruction. For the NCC, it is documented that westward subduction of the paleo-Pacific plate should have initiated at the transition from the Middle-to-Late Jurassic, and resulted in the change of tectonic regime of eastern China. We propose that subduction, rollback and retreat of oceanic plates and dehydration of stagnant slabs are the main dynamic factors responsible for both craton destruction and concentration of mineral deposits, such as gold, in the overriding continental plate. Based on global distribution of gold deposits, we suggest that convergent plate margins are the most important setting for large gold concentrations. Therefore, decratonic gold deposits appear to occur preferentially in regions with oceanic subduction and overlying continental lithospheric destruction/modification/growth.

  6. Blastwall effects on down range explosively-induced overpressure.

    SciTech Connect

    Saul, W. Venner; Preece, Dale S.

    2003-07-01

    Blastwalls are often assumed to be the answer for facility protection from malevolent explosive assault, particularly from large vehicle bombs (LVB's). The assumption is made that the blastwall, if it is built strong enough to survive, will provide substantial protection to facilities and people on the side opposite the LVB. This paper will demonstrate through computer simulations and experimental data the behavior of explosively induced air blasts during interaction with blastwalls. It will be shown that air blasts can effectively wrap around and over blastwalls. Significant pressure reduction can be expected on the downstream side of the blastwall but substantial pressure will continue to propagate. The effectiveness of the blastwall to reduce blast overpressure depends on the geometry of the blastwall and the location of the explosive relative to the blastwall.

  7. Ares I-X Post Flight Ignition Overpressure Review

    NASA Technical Reports Server (NTRS)

    Alvord, David A.

    2010-01-01

    Ignition Overpressure (IOP) is an unsteady fluid flow and acoustic phenomena caused by the rapid expansion of gas from the rocket nozzle within a ducted launching space resulting in an initially higher amplitude pressure wave. This wave is potentially dangerous to the structural integrity of the vehicle. An in-depth look at the IOP environments resulting from the Ares I-X Solid Rocket Booster configuration showed high correlation between the pre-flight predictions and post-flight analysis results. Correlation between the chamber pressure and IOP transients showed successful acoustic mitigation, containing the strongest IOP waves below the Mobile Launch Pad deck. The flight data allowed subsequent verification and validation of Ares I-X unsteady fluid ducted launcher predictions, computational fluid dynamic models, and strong correlation with historical Shuttle data.

  8. Blast overpressure after tire explosion: a fatal case.

    PubMed

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

    2013-12-01

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

  9. Middle ear overpressure treatment of endolymphatic hydrops in guinea pigs.

    PubMed

    Sakikawa, Y; Kimura, R S

    1997-01-01

    Guinea pigs placed outside or inside a pressure chamber and exposed to 49.2 cm H2O overpressure continuously for 24 h immediately after blockage of the endolymphatic duct showed no significant difference in the magnitude of endolymphatic hydrops when compared to controls, although there was a slight indication of a volume decrease in the outside-treatment group and an increase in the inside-treatment group. A pressure increase of 49.2 cm H2O in the external auditory canal for 1 h twice a day for 2 weeks outside the chamber significantly inhibited the development of hydrops. The latter result supports the merit of pressure application through the external auditory canal as a treatment for Meniere's disease.

  10. Ballistic range investigation of sonic-boom overpressures in water.

    NASA Technical Reports Server (NTRS)

    Malcolm, G. N.; Intrieri, P. F.

    1972-01-01

    An investigation of sonic-boom overpressures in water has been conducted by gun-launching small cone-cylinder models over water. Flights were conducted at Mach numbers of 2.7 and 5.7, in air, corresponding to Mach numbers of 0.6 and 1.3, respectively, in water. Shadowgraph pictures and underwater pressure measurements indicate that for horizontal flights at Mach numbers below Mach 4.4 in air (i.e., subsonic relative to the speed of sound in water) the resulting underwater disturbance is an acoustic wave whose peak pressure attenuates rapidly with water depth. In contrast, at supersonic Mach numbers, relative to water, the incident shock wave at the surface is transmitted into the water as a propagating shock wave and the peak pressure associated with it does not attenuate with water depth.

  11. Reconstruction of fluid (over-)pressure evolution from sub-seismic fractures in folds and foreland basins

    NASA Astrophysics Data System (ADS)

    Beaudoin, Nicolas; Lacombe, Olivier; Bellahsen, Nicolas; Emmanuel, Laurent

    2013-04-01

    Deciphering the evolution of pressure, temperature and chemistry of fluids during fold history is a challenging problem. While temperature and chemistry of paleo-fluids can be determined using vein mineralizations in fault zones and/or in diffuse sub-seismic fracture sets, few methods exist to constrain the evolution through time of fluid pressure, especially when no hydrocarbons are encountered. This contribution aims at presenting and discussing a new approach to reconstruct the evolution of fluid pressure based on paleostress analyses. The combination of stress inversion of fault slip data and calcite twin data with rock mechanics data allows determining both the orientations and the magnitudes of principal stresses during basin evolution. Assuming no burial change through time, the comparison of the computed magnitudes of the effective vertical stress with its theoretical value (calculated with respect to the paleo-overburden and hydrostatic fluid pressure) may be used to quantitatively estimate fluid overpressure in limestones at different steps of the tectonic history. Alternatively, if hydrostatic fluid pressure is assumed to prevail in the system from step to step, results likely reflect overburden variations. The application focuses on the diffuse fracture populations observed in limestones of the famous Mississippian-Permian Madison and Phosphoria formations in Laramide basement-cored folds of the Rocky Mountains: the Sheep Mountain and the Rattlesnake Mountain anticlines (Bighorn Basin, Wyoming, USA). The location of these basement-folds on each edge of the Bighorn Basin ensures that depositional and erosional events can be neglected before folding, and thus grants the opportunity to constrain and to discuss the level of fluid overpressure during both the Sevier (thin-skinned) and Laramide (thick-skinned) related Layer-Parallel Shortening (LPS) phases at both fold scale and basin scale. Results highlight an initial fluid overpressure in limestones buried

  12. Single-Event Effect Report for EPC Series eGaN FETs: The Effect of Load Conditions on Destructive SEE

    NASA Technical Reports Server (NTRS)

    Scheick, Leif

    2014-01-01

    Recent testing of Enhanced Power Conversion (EPC) eGaN FET devices design for power use has shown that the devices are susceptible to Single-Event Effects (SEE) that degrade or destroy the device. The exact mechanism of the SEE is not known. The testing so far has been in the static condition, in the fully off condition, and with minimal load conditions. These conditions may not be worst case. This report presents the results of a study that tests some of the load conditions for SEE. The EPC2012 and EPC1012 were chosen for the test. The tests were performed the TAMU radiation effects facility in May and June of 2013.

  13. Frictionite as evidence for a large Late Quaternary rockslide near Kanchenjunga, Sikkim Himalayas, India — Implications for extreme events in mountain relief destruction

    NASA Astrophysics Data System (ADS)

    Weidinger, Johannes T.; Korup, Oliver

    2009-01-01

    We present sedimentologic and petrographic field evidence of an extremely large (~ 2.5 × 10 9 m 3) Late Quaternary rockslide around Dzongri, 24 km S of Kanchenjunga (8585 m a.s.l.). Widespread occurrence of shattered leucogranites and migmatites deposited discordantly on top of undisturbed augen gneisses, and separated by micro-brecciated sliding surfaces indicate rapid movement during a large rockslide event. Occurrence of frictionite (= hyalomylonite) in mineral samples indicates short-term temperatures of ~ 600 °C in the moving rockslide mass along a 12° sliding plane. From a SW direction of movement we infer a source 8 km NE of the deposit, ~ 5 km S of Pandim (6691 m a.s.l.), where today a thick leucogranite intrusion marks a zone of weakness and failure of a postulated former mountain crest. The mechanism of movement, the dip of the sliding surface, and the deposit preservation along ridge tops require that the Dzongri rockslide ran out over an ice-filled Prek Chu valley. Hence, we prefer earthquake shaking over undercutting and glacial debuttressing as a possible trigger mechanism. A regional review of other similarly large and catastrophic Himalayan rockslides indicates that leucogranite intrusions are highly conducive to large-scale failure in the Higher Himalayan Crystalline (HHC). Importantly, high erosion rates have rendered this large rockslide deposit undetectable by remote sensing or digital elevation data, which are commonly used for identifying evidence of such extreme events. Quantifying the contribution of such giant landslides in destroying some of the highest relief on Earth will thus need further research attention.

  14. The effects of simulated fire events on the creation and destruction of soil water repellency using vegetation and soil samples from a desert shrub grassland

    NASA Astrophysics Data System (ADS)

    Over, T. M.; Pratte, S.; Frost, B.; Blitz, J.

    2010-12-01

    Fire-induced soil water repellency has been shown to interact with aeolian processes to enhance the heterogeneity of arid landscapes. To investigate aspects of these processes, vegetation (black grama grass and creosote bush) and soil samples from a field site in the northern Chihuahuan desert of central New Mexico were prepared and heated to temperatures ranging from 100 to 600 degrees Celsius in a tube furnace for one minute to simulate fire events. The vegetation samples were prepared by drying, grinding, and mixing with a clean sand in different concentrations, and the soil samples were passed through a 2 mm sieve. The samples were tested before and after heating using the molarity of ethanol (MED) drop test to determine the effect of heating to different temperatures on soil water repellency. The results show that some heating enhances repellency but higher temperatures destroy it. Gas chromatography - mass spectrometric analysis of soil extracts was also used to investigate the presence of some molecules that may be associated with soil water repellency before and after the heating experiments.

  15. Lung injury and recovery after exposure to blast overpressure.

    PubMed

    Chavko, Mikulas; Prusaczyk, W Keith; McCarron, Richard M

    2006-10-01

    A critical immediate determinant of survival after exposure to blast overpressure (BOP) is pulmonary damage, but mechanisms of injury and the course of recovery are not well understood. The objective of this study was to characterize the progression of oxidative and inflammatory responses in lungs as well as the activation of consequent protective mechanisms after exposure to medium intensity BOP. Rats were exposed to a moderate (approximately 120 kPa) level of BOP in a pneumatically driven shock tube. At different times (2-192 hours) after exposure, lungs were examined for pathologic signs of injury, markers of inflammatory responses, and indicators of oxidative and nitrative damage. The results showed a postblast activation of inflammatory response (increase of myeloperoxidase activity, CINC-1, ICAM-1, and iNOS), increase in protein oxidation and nitration, and development of gross diffused hemorrhage in lungs. The initial phase of lung damage that peaked at 24 to 48 hours after exposure to BOP was followed by gradual dissolution of inflammation and oxidation that were complete by 192 hours. Resolution of morphologic damage and inflammation in lungs concurred with activation of expression of antioxidant enzymes heme oxygenase-1 (HO-1) and manganese superoxide dismutase (MnSOD). Plasma level of gelsolin, a marker of acute lung damage was decreased at 24 hours postblast and later returned to the control level. The study shows the role of adaptive anti-oxidant and anti- inflammatory mechanisms in lung recovery after injury caused by exposure to BOP.

  16. A complete high integrity overpressure pipeline protection system

    SciTech Connect

    High, G.; Loth, W.D.

    1995-12-31

    Although most often associated with high-pressure production, a reliable system enabling subsea wells to be produced safely at long tie-back distances through flowlines rated to less than shut-in wellhead pressure offers cost savings for many developments. Previous work has shown that there is a small but finite probability of conventional flow control systems failing to shut off damaging overpressures. In most cases, this will arise from mechanical problems which are more likely causes than electronic failure within the production control system. The proposed system provides a viable means of implementing a pressure specification break through the use of a modular, configurable system comprising four main components. The system is semi-autonomous, with dedicated pressure sensors and high integrity electronics being incorporated to avoid common mode system failures. Routine telemetry and reset capability would be conducted through the electro-hydraulic production control system. The near-term availability of this protection system is an important consideration in justifying the economic viability of many marginal field developments.

  17. The development of a cryogenic over-pressure pump

    NASA Astrophysics Data System (ADS)

    Alvarez, M.; Cease, H.; Flaugher, B.; Flores, R.; Garcia, J.; Lathrop, A.; Ruiz, F.

    2014-01-01

    A cryogenic over-pressure pump (OPP) was tested in the prototype telescope liquid nitrogen (LN2) cooling system for the Dark Energy Survey (DES) Project. This OPP consists of a process cylinder (PC), gas generator, and solenoid operated valves (SOVs). It is a positive displacement pump that provided intermittent liquid nitrogen (LN2) flow to an array of charge couple devices (CCDs) for the prototype Dark Energy Camera (DECam). In theory, a heater submerged in liquid would generate the drive gas in a closed loop cooling system. The drive gas would be injected into the PC to displace that liquid volume. However, due to limitations of the prototype closed loop nitrogen system (CCD cooling system) for DECam, a quasiclosed-loop nitrogen system was created. During the test of the OPP, the CCD array was cooled to its designed set point temperature of 173K. It was maintained at that temperature via electrical heaters. The performance of the OPP was captured in pressure, temperature, and flow rate in the CCD LN2 cooling system at Fermi National Accelerator Laboratory (FNAL).

  18. NASTRAN Analysis Comparison to Shock Tube Tests Used to Simulate Nuclear Overpressures

    NASA Technical Reports Server (NTRS)

    Wheless, T. K.

    1985-01-01

    This report presents a study of the effectiveness of the NASTRAN computer code for predicting structural response to nuclear blast overpressures. NASTRAN's effectiveness is determined by comparing results against shock tube tests used to simulate nuclear overpressures. Seven panels of various configurations are compared in this study. Panel deflections are the criteria used to measure NASTRAN's effectiveness. This study is a result of needed improvements in the survivability/vulnerability analyses subjected to nuclear blast.

  19. Kevlar Vest Protection Against Blast Overpressure Brain Injury: Systemic Contributions to Injury Etiology

    DTIC Science & Technology

    2014-11-01

    Award Number: W81XWH-08-2-0017 TITLE: " Kevlar Vest Protection Against Blast Overpressure Brain Injury: Systemic Contributions to Injury Etiology...TITLE AND SUBTITLE 5a. CONTRACT NUMBER “ Kevlar Vest Protection Against Blast Overpressure Brain Injury: Systemic Contributions to Injury Etiology...traumatic brain injury (bTBI) is largely undefined. Along with reducing mortality, in preliminary experiments Kevlar vests significantly protected

  20. The quantitative assessment of domino effect caused by overpressure. Part II. Case studies.

    PubMed

    Cozzani, Valerio; Salzano, Ernesto

    2004-03-19

    A quantitative assessment of the contribution to industrial risk of domino effect due to overpressure was undertaken by using the damage probability models developed in part I. Two case studies derived from the actual lay-out of an oil refinery were analyzed. Individual and societal risk indexes were estimated both in the absence and in the presence of the domino effects caused by overpressure. An increase of individual risk up to an order of magnitude was found when considering domino effects.

  1. Blast overpressure induced structural and functional changes in the auditory system.

    PubMed

    Patterson, J H; Hamernik, R P

    1997-07-25

    Blast overpressure of sufficient intensity can produce injury to various organ systems. Unprotected ears result in the auditory system being the most susceptible. The injuries to the auditory system include: rupture of the tympanic membrane, dislocation or fracture of the ossicular chain, and damage to the sensory structures on the basilar membrane. All these injuries can be characterized as a form of mechanical damage to the affected structure. Injury to the sensory structures on the basilar membrane leads to temporary and permanent loss of hearing sensitivity. The temporary component of the hearing loss shows a time course after removal from the noise which frequently will include an initial increase in hearing loss followed by a recovery period during which threshold may return to preexposure levels or stabilize at a higher level which represents a permanent loss of hearing sensitivity. This type of recovery function suggests that there are damage processes which continue after the traumatic event and that intervention might mitigate some of the damage and hearing loss.

  2. Overpressure and noise due to multiple airbag systems in a passenger car

    NASA Astrophysics Data System (ADS)

    Hickling, Robert; Henning, Peter J.; Newton, Gary, Jr.

    2002-11-01

    Multiple airbag systems in passenger cars can generate overpressure and noise that may be hazardous to human hearing. Overpressure is compression of the air inside a closed compartment caused by deployment of the bags. Noise results from the action of the gas inflating the bags. SAE J247 provides a standard for measuring the combination of overpressure and noise in a passenger compartment. A special microphone has recently been developed that meets this standard, which operates down to a fraction of a hertz. Details of the microphone are given. Little appears to have been published on the overpressure and noise of modern multiple airbag systems, but early results [R. Hickling, ''The noise of the automotive safety air cushion,'' Noise Control Eng., May-June, 110-121 (1976)] provide a basic understanding of the phenomenon. Spectral data shows that peak overpressure occurs at about 2 to 3 Hz. A significant reduction in overpressure and noise can be achieved with an aspirating airbag, originally developed at General Motors, whose outer structure is inflated with gas from the inflator, and whose inner structure draws in air from the passenger compartment through one-way cloth valves. Tests have shown that such bags function well when impacted.

  3. Late secondary porosity associated with overpressure leak-off: Evidence from the Fulmar Formation, central North Sea

    SciTech Connect

    Darby, D.; Wilkinson, M.; Haszeldine, S. )

    1996-01-01

    The Upper Jurassic Fulmar sandstone of the Central North Sea is characterized by deep burial (greater than 4000m burial depth) and extremely high levels of overpressure (up to 40MPa overpressure at 4500m depth). High overpressure may support high porosity at great depths, and so the relationship between overpressure and porosity is of considerable commercial importance in deep prospects. Simulating the porosity evolution and overpressure of the sandstones via a two-dimensional basin model reveals that for the majority of Fulmar Fm. sandstones, the porosity evolution is a simple pattern of reduction during burial to present-day values of 15-20%. However, in wells sited close to structurally-elevated overpressure leak-off points, the porosity is anomalously high (up to 35% at 4500m depth). We suggest that pressure-induced vertical fluid flow at over-pressure leak points allows removal of the products of feldspar dissolution. This process allows porosity to increase from an end-Miocene low of 15-20% to the present-day values of 30-35%. Developing voids require support by overpressure, and so this increase in porosity must have occurred as the sandstones became highly over-pressured during rapid Plio-Pleistocene subsidence. We infer that overpressured sandstones may behave as open geochemical systems, and that 10-15% porosity has formed in regions of the Central Graben during deep burial in the last 5 Ma.

  4. Late secondary porosity associated with overpressure leak-off: Evidence from the Fulmar Formation, central North Sea

    SciTech Connect

    Darby, D.; Wilkinson, M.; Haszeldine, S.

    1996-12-31

    The Upper Jurassic Fulmar sandstone of the Central North Sea is characterized by deep burial (greater than 4000m burial depth) and extremely high levels of overpressure (up to 40MPa overpressure at 4500m depth). High overpressure may support high porosity at great depths, and so the relationship between overpressure and porosity is of considerable commercial importance in deep prospects. Simulating the porosity evolution and overpressure of the sandstones via a two-dimensional basin model reveals that for the majority of Fulmar Fm. sandstones, the porosity evolution is a simple pattern of reduction during burial to present-day values of 15-20%. However, in wells sited close to structurally-elevated overpressure leak-off points, the porosity is anomalously high (up to 35% at 4500m depth). We suggest that pressure-induced vertical fluid flow at over-pressure leak points allows removal of the products of feldspar dissolution. This process allows porosity to increase from an end-Miocene low of 15-20% to the present-day values of 30-35%. Developing voids require support by overpressure, and so this increase in porosity must have occurred as the sandstones became highly over-pressured during rapid Plio-Pleistocene subsidence. We infer that overpressured sandstones may behave as open geochemical systems, and that 10-15% porosity has formed in regions of the Central Graben during deep burial in the last 5 Ma.

  5. Fluid pressures in overpressured Forbes Formation, Sacramento Valley, California

    SciTech Connect

    Price, C.A.

    1988-03-01

    Initial shut-in pressures obtained from drill-stem tests, mud weights, and shale-compaction data were used to determine the formation fluid-pressure distribution in the southern Grimes gas field. Initial shut-in pressures in overpressured gas-bearing Forbes sandstones range from 3252 to 6660 psi. Pressure gradients range from 0.446 to 0.745 psi/ft. Regional initial shut-in pressure data suggest that (1) pressures appear to increase dramatically at approximately 7700 ft (2339 m) below sea level, (2) pressures generally increase with depth above 8200 ft (2491 m), but are highly variable below 8200 ft, and (3) the approximate depth to the top of geopressures is 5500 ft (1671 m) below sea level. Fluid pressures generally decrease from northeast to southwest through the region and from north to south within the westernmost fault block. Mud-weight data give maximum pressures for any depth. The maximum possible pressure gradient in the southern Grimes gas field is 0.847 psi/ft. The relationship between initial shut-in pressure and the amount of gas tested during drill-stem tests was also examined. More than 3000 MCFGD was tested only where the fluid pressure gradient was between 0.510 and 0.700 psi/ft. Twice as many drill-stem tests showed little or no gas when the fluid-pressure gradient exceeded 0.700 psi/ft than when it was less than 0.700 psi/ft. Fluid-pressure gradients greater than 0.700 psi/ft were encountered only below 8000 ft (2430 m); therefore, the probability of testing, and possibly producing, 3000 MCFGD decreases below 8000 ft.

  6. Fluid overpressure estimates from the aspect ratios of mineral veins

    NASA Astrophysics Data System (ADS)

    Philipp, Sonja L.

    2012-12-01

    Several hundred calcite veins and (mostly) normal faults were studied in limestone and shale layers of a Mesozoic sedimentary basin next to the village of Kilve at the Bristol Channel (SW-England). The veins strike mostly E-W (239 measurements), that is, parallel with the associated normal faults. The mean vein dip is 73°N (44 measurements). Field observations indicate that these faults transported the fluids up into the limestone layers. The vein outcrop (trace) length (0.025-10.3 m) and thickness (0.1-28 mm) size distributions are log-normal. Taking the thickness as the dependent variable and the outcrop length as the independent variable, linear regression gives a coefficient of determination (goodness of fit) of R2 = 0.74 (significant with 99% confidence), but natural logarithmic transformation of the thickness-length data increases the coefficient of determination to R2 = 0.98, indicating that nearly all the variation in thickness can be explained in terms of variation in trace length. The geometric mean of the aspect (length/thickness) ratio, 451, gives the best representation of the data set. With 95% confidence, the true geometric mean of the aspect ratios of the veins lies in the interval 409-497. Using elastic crack theory, appropriate elastic properties of the host rock, and the mean aspect ratio, the fluid overpressure (that is, the total fluid pressure minus the normal stress on the fracture plane) at the time of vein formation is estimated at around 18 MPa. From these results, and using the average host rock and water densities, the depth to the sources of the fluids (below the present exposures) forming the veins is estimated at between around 300 m and 1200 m. These results are in agreement to those obtained by independent isotopic studies and indicate that the fluids were of rather local origin, probably injected from sill-like sources (water sills) inside the sedimentary basin.

  7. Use of overpressure to assess the role of bubbles in focused ultrasound lesion shape in vitro.

    PubMed

    Bailey, M R; Couret, L N; Sapozhnikov, O A; Khokhlova, V A; ter Haar, G; Vaezy, S; Shi, X; Martin, R; Crum, L A

    2001-05-01

    Overpressure--elevated hydrostatic pressure--was used to assess the role of gas or vapor bubbles in distorting the shape and position of a high-intensity focused ultrasound (HIFU) lesion in tissue. The shift from a cigar-shaped lesion to a tadpole-shaped lesion can mean that the wrong area is treated. Overpressure minimizes bubbles and bubble activity by dissolving gas bubbles, restricting bubble oscillation and raising the boiling temperature. Therefore, comparison with and without overpressure is a tool to assess the role of bubbles. Dissolution rates, bubble dynamics and boiling temperatures were determined as functions of pressure. Experiments were made first in a low-overpressure chamber (0.7 MPa maximum) that permitted imaging by B-mode ultrasound (US). Pieces of excised beef liver (8 cm thick) were treated in the chamber with 3.5 MHz for 1 to 7 s (50% duty cycle). In situ intensities (I(SP)) were 600 to 3000 W/cm(2). B-mode US imaging detected a hyperechoic region at the HIFU treatment site. The dissipation of this hyperechoic region following HIFU cessation corresponded well with calculated bubble dissolution rates; thus, suggesting that bubbles were present. Lesion shape was then tested in a high-pressure chamber. Intensities were 1300 and 1750 W/cm(2) ( +/- 20%) at 1 MHz for 30 s. Hydrostatic pressures were 0.1 or 5.6 MPa. At 1300 W/cm(2), lesions were cigar-shaped, and no difference was observed between lesions formed with or without overpressure. At 1750 W/cm(2), lesions formed with no overpressure were tadpole-shaped, but lesions formed with high overpressure (5.6 MPa) remained cigar-shaped. Data support the hypothesis that bubbles contribute to the lesion distortion.

  8. A study of sonic boom overpressure trends with respect to weight, altitude, Mach number, and vehicle shaping

    NASA Technical Reports Server (NTRS)

    Needleman, Kathy E.; Mack, Robert J.

    1990-01-01

    This paper presents and discusses trends in nose shock overpressure generated by two conceptual Mach 2.0 configurations. One configuration was designed for high aerodynamic efficiency, while the other was designed to produce a low boom, shaped-overpressure signature. Aerodynamic lift, sonic boom minimization, and Mach-sliced/area-rule codes were used to analyze and compute the sonic boom characteristics of both configurations with respect to cruise Mach number, weight, and altitude. The influence of these parameters on the overpressure and the overpressure trends are discussed and conclusions are given.

  9. Habitat destruction and the extinction debt revisited

    SciTech Connect

    Loehle, C.

    1996-02-01

    A very important analysis of the problem of habitat destruction concluded that such destruction may lead to an extinction debt, which is the irreversible loss of species following a prolonged transient or delay. An error in interpretation of this model led the authors to apply the results to all types of habitat destruction, but in fact the model applies only to an across-the-board decrease in fecundity, not to disturbances. For repeated, spatially random disturbance, a different model applies. For habitat destruction on regional scales (reduction in ecosystem area without disturbance in remnant areas), one must, in contrast, apply species-area relations based on the distribution of different habitat types (e.g., elevational and rainfall gradients, physiographic and edaphic variability). The error in interpretation of the basic model is presented, followed by clarification of model usage and development of a new model that applies to disturbance events.

  10. Pore pressure estimation from velocity data: Accounting for overpressure mechanisms besides undercompaction

    SciTech Connect

    Bowers, G.L.

    1995-06-01

    A new method for estimating pore pressure from formation sonic velocity data is presented. Unlike previous techniques, this method accounts for excess pressure generated by both undercompaction, and fluid expansion mechanisms such as aquathermal pressuring, hydrocarbon maturation, clay diagenesis, and charging from other zones. The method is an effective stress approach; the effective stress is computed from the velocity, and the result is subtracted from the overburden stress to obtain pore pressure. to include multiple sources of overpressure, a pair of velocity-vs.-effective-stress relations are introduced. One relation accounts for normal pressure and overpressure caused by undercompaction. The second is applied inside velocity reversal zones caused by fluid expansion mechanisms. Example applications of the method are presented from the U.S. gulf coast, the Gulf of Mexico, and the Central North Sea. some other pore pressure estimation approaches are also examined to demonstrate how these techniques have unknowingly accounted for overpressure mechanisms other than undercompaction. It is also explained how velocity-vs.-effective-stress data can be used to identify the general cause of overpressure in an area. For instance, the empirical correlation of Hottman and Johnson indicates that overpressure along the US gulf coast cannot be due only to undercompaction.

  11. Effect of overpressure and pulse repetition frequency on cavitation in shock wave lithotripsy.

    PubMed

    Sapozhnikov, Oleg A; Khokhlova, Vera A; Bailey, Michael R; Williams, James C; McAteer, James A; Cleveland, Robin O; Crum, Lawrence A

    2002-09-01

    Cavitation appears to contribute to tissue injury in lithotripsy. Reports have shown that increasing pulse repetition frequency [(PRF) 0.5-100 Hz] increases tissue damage and increasing static pressure (1-3 bar) reduces cell damage without decreasing stone comminution. Our hypothesis is that overpressure or slow PRF causes unstabilized bubbles produced by one shock pulse to dissolve before they nucleate cavitation by subsequent shock pulses. The effects of PRF and overpressure on bubble dynamics and lifetimes were studied experimentally with passive cavitation detection, high-speed photography, and B-mode ultrasound and theoretically. Overpressure significantly reduced calculated (100-2 s) and measured (55-0.5 s) bubble lifetimes. At 1.5 bar static pressure, a dense bubble cluster was measured with clinically high PRF (2-3 Hz) and a sparse cluster with clinically low PRF (0.5-1 Hz), indicating bubble lifetimes of 0.5-1 s, consistent with calculations. In contrast to cavitation in water, high-speed photography showed that overpressure did not suppress cavitation of bubbles stabilized on a cracked surface. These results suggest that a judicious use of overpressure and PRF in lithotripsy could reduce cavitation damage of tissue while maintaining cavitation comminution of stones.

  12. Rapid sedimentation and overpressure in shallow sediments of the Bering Trough, offshore southern Alaska

    NASA Astrophysics Data System (ADS)

    Daigle, Hugh; Worthington, Lindsay L.; Gulick, Sean P. S.; Van Avendonk, Harm J. A.

    2017-04-01

    Pore pressures in sediments at convergent margins play an important role in driving chemical fluxes and controlling deformation styles and localization. In the Bering Trough offshore Southern Alaska, extreme sedimentation rates over the last 140 kyr as a result of glacial advance/retreats on the continental shelf have resulted in elevated pore fluid pressures in slope sediments overlying the Pamplona Zone fold and thrust belt, the accretionary wedge resulting from subduction of the Yakutat microplate beneath the North American Plate. Based on laboratory experiments and downhole logs acquired at Integrated Ocean Drilling Program Site U1421, we predict that the overpressure in the slope sediments may be as high as 92% of the lithostatic stress. Results of one-dimensional numerical modeling accounting for changes in sedimentation rate over the last 130 kyr predicted overpressures that are consistent with our estimates, suggesting that the overpressure is a direct result of the rapid sedimentation experienced on the Bering shelf and slope. Comparisons with other convergent margins indicate that such rapid sedimentation and high overpressure are anomalous in sediments overlying accretionary wedges. We hypothesize that the shallow overpressure on the Bering shelf/slope has fundamentally altered the deformation style within the Pamplona Zone by suppressing development of faults and may inhibit seismicity by focusing faulting elsewhere or causing deformation on existing faults to be aseismic. These consequences are probably long-lived as it may take several million years for the excess pressure to dissipate.

  13. Investigation on the relationship between overpressure and sub-harmonic response from encapsulated microbubbles

    NASA Astrophysics Data System (ADS)

    Wu, Jun; Fan, Ting-Bo; Xu, Di; Zhang, Dong

    2014-10-01

    Sub-harmonic component generated from microbubbles is proven to be potentially used in noninvasive blood pressure measurement. Both theoretical and experimental studies are performed in the present work to investigate the dependence of the sub-harmonic generation on the overpressure with different excitation pressure amplitudes and pulse lengths. With 4-MHz ultrasound excitation at an applied acoustic pressure amplitude of 0.24 MPa, the measured sub-harmonic amplitude exhibits a decreasing change as overpressure increases; while non-monotonic change is observed for the applied acoustic pressures of 0.36 MPa and 0.48 MPa, and the peak position in the curve of the sub-harmonic response versus the overpressure shifts toward higher overpressure as the excitation pressure amplitude increases. Furthermore, the exciting pulse with long duration could lead to a better sensitivity of the sub-harmonic response to overpressure. The measured results are explained by the numerical simulations based on the Marmottant model. The numerical simulations qualitatively accord with the measured results. This work might provide a preliminary proof for the optimization of the noninvasive blood pressure measurement through using sub-harmonic generation from microbubbles.

  14. Overpressure blast injury-induced oxidative stress and neuroinflammation response in rat frontal cortex and cerebellum.

    PubMed

    Toklu, Hale Z; Yang, Zhihui; Oktay, Sehkar; Sakarya, Yasemin; Kirichenko, Nataliya; Matheny, Michael K; Muller-Delp, Judy; Strang, Kevin; Scarpace, Philip J; Wang, Kevin K W; Tümer, Nihal

    2017-04-15

    Overpressure blast-wave induced brain injury (OBI) and its long-term neurological outcome pose significant concerns for military personnel. Our aim is to investigate the mechanism of injury due to OBI. Rats were divided into 3 groups: (1) Control, (2) OBI (exposed 30psi peak pressure, 2-2.5ms), (3) Repeated OBI (r-OBI) (three exposures over one-week period). Lung and brain (cortex and cerebellum) tissues were collected at 24h post injury. The neurological examination score was worse in OBI and r-OBI (4.2±0.6 and 3.7±0.5, respectively) versus controls (0.7±0.2). A significant positive correlation between lung and brain edema was found. Malondialdehyde (index for lipid peroxidation), significantly increased in OBI and r-OBI groups in cortex (p<0.05) and cerebellum (p<0.01-0.001). The glutathione (endogenous antioxidant) level decreased in cortex (p<0.01) and cerebellum (p<0.05) of r-OBI group when compared with the controls. Myeloperoxidase activity indicating neutrophil infiltration, was significantly (p<0.01-0.05) elevated in r-OBI. Additionally, tissue thromboplastin activity, a coagulation marker, was elevated, indicating a tendency to bleed. NGF and NF-κB proteins along with Iba-1 and GFAP immunoreactivity significantly augmented in the frontal cortex demonstrating microglial activation. Serum biomarkers of injury, NSE, TNF-alpha and leptin, were also elevated. OBI triggers both inflammation and oxidative injury in the brain. This data in conjunction with our previous observations suggests that OBI triggers a cascade of events beginning with impaired cerebral vascular function leading to ischemia and chronic neurological consequences. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Impact of copper overpressure on the synthesis of hexagonal boron nitride atomic layers.

    PubMed

    Bresnehan, Michael S; Bhimanapati, Ganesh R; Wang, Ke; Snyder, David W; Robinson, Joshua A

    2014-10-08

    Hexagonal boron nitride (h-BN) atomic layers are synthesized on polycrystalline copper foils via a novel chemical vapor deposition (CVD) process that maintains a vapor-phase copper overpressure during growth. Compared to h-BN films grown without a copper overpressure, this process results in a >10× reduction of 3-dimensional BN fullerene-like surface features, a reduction of carbon and oxygen contamination of 65% and 62%, respectively, an increase in h-BN grain size of >2×, and an 89% increase in electrical breakdown strength.

  16. 46 CFR 39.6003 - Overpressure and underpressure protection during stripping or gas-freeing operations-B/ALL.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Overpressure and underpressure protection during stripping or gas-freeing operations-B/ALL. 39.6003 Section 39.6003 Shipping COAST GUARD, DEPARTMENT OF... § 39.6003 Overpressure and underpressure protection during stripping or gas-freeing operations—B/ALL...

  17. 46 CFR 39.6003 - Overpressure and underpressure protection during stripping or gas-freeing operations-B/ALL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Overpressure and underpressure protection during stripping or gas-freeing operations-B/ALL. 39.6003 Section 39.6003 Shipping COAST GUARD, DEPARTMENT OF... § 39.6003 Overpressure and underpressure protection during stripping or gas-freeing operations—B/ALL...

  18. Overpressure, Flow Focusing, Compaction and Slope Stability on the continental slope: Insights from IODP Expedition 308

    NASA Astrophysics Data System (ADS)

    Flemings, P. B.

    2010-12-01

    Integrated Ocean Drilling Program Expepedition 308 used direct measurements of pore pressure, analysis of hydromechanical properties, and geological analysis to illuminate how sedimentation, flow focusing, overpressure, and slope stability couple beneath the seafloor on the deepwater continental slope in the Gulf of Mexico. We used pore pressure penetrometers to measure severe overpressures (60% of the difference between lithostatic stress and hydrostatic pressure) that extend from the seafloor for 100’s of meters. We ran uniaxial consolidation experiments on whole core and found that although permeability is relatively high near the seafloor, the sediments are highly compressible. As a result, the coefficient of consolidation (the hydraulic diffusivity) is remarkably constant over a large range of effective stresses. This behavior accounts for the high overpressure that begins near the seafloor and extends to depth. Forward modeling suggests that flow is driven laterally along a permeable unit called the Blue Unit. Calculations suggest that soon after deposition, lateral flow lowered the effective stress and triggered the submarine landslides that we observe. Later in the evolution of this system, overpressure may have pre-conditioned the slope to failure by earthquakes. Results from IODP Expedition 308 illustrate how pore pressure and sedimentation control the large-scale form of continental margins, how submarine landslides form, and provide strategies for designing stable drilling programs.

  19. 33 CFR 154.814 - Facility requirements for vessel vapor overpressure and vacuum protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... vapor overpressure and vacuum protection. 154.814 Section 154.814 Navigation and Navigable Waters COAST... vacuum protection. (a) A facility's vapor collection system must have the capacity for collecting cargo... vessel's cargo tanks between 80 percent of the highest setting of any of the vessel's vacuum...

  20. 33 CFR 154.814 - Facility requirements for vessel vapor overpressure and vacuum protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... vapor overpressure and vacuum protection. 154.814 Section 154.814 Navigation and Navigable Waters COAST... vacuum protection. (a) A facility's vapor collection system must have the capacity for collecting cargo... vessel's cargo tanks between 80 percent of the highest setting of any of the vessel's vacuum...

  1. 33 CFR 154.814 - Facility requirements for vessel vapor overpressure and vacuum protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... vapor overpressure and vacuum protection. 154.814 Section 154.814 Navigation and Navigable Waters COAST... vacuum protection. (a) A facility's vapor collection system must have the capacity for collecting cargo... vessel's cargo tanks between 80 percent of the highest setting of any of the vessel's vacuum...

  2. 33 CFR 154.814 - Facility requirements for vessel vapor overpressure and vacuum protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... vapor overpressure and vacuum protection. 154.814 Section 154.814 Navigation and Navigable Waters COAST... vacuum protection. (a) A facility's vapor collection system must have the capacity for collecting cargo... vessel's cargo tanks between 80 percent of the highest setting of any of the vessel's vacuum...

  3. 14 CFR 417.229 - Far-field overpressure blast effects analysis.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... explosions resulting from debris impacts, including the potential for mixing of liquid propellants; (4... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Far-field overpressure blast effects analysis. 417.229 Section 417.229 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION...

  4. 14 CFR 417.229 - Far-field overpressure blast effects analysis.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... explosions resulting from debris impacts, including the potential for mixing of liquid propellants; (4... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Far-field overpressure blast effects analysis. 417.229 Section 417.229 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION...

  5. 14 CFR 417.229 - Far-field overpressure blast effects analysis.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... explosions resulting from debris impacts, including the potential for mixing of liquid propellants; (4... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Far-field overpressure blast effects analysis. 417.229 Section 417.229 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION...

  6. 14 CFR 417.229 - Far-field overpressure blast effects analysis.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... explosions resulting from debris impacts, including the potential for mixing of liquid propellants; (4... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Far-field overpressure blast effects analysis. 417.229 Section 417.229 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION...

  7. Thermodynamic and hydrodynamic constraints on overpressure caused by hydrate dissociation: A pore-scale model

    NASA Astrophysics Data System (ADS)

    Holtzman, R.; Juanes, R.

    2011-07-01

    It has been suggested that volume expansion caused by hydrate dissociation in sediment pores can result in large overpressure, which in turn may destabilize the sediment and trigger massive submarine landslides. Here, we investigate the pressure evolution during thermally-induced dissociation, by means of a pore-scale model that couples dissociation kinetics, multiphase flow and geomechanics. Dissociation is controlled by a self-preservation mechanism: increasing pore pressure reduces the driving force for dissociation. Hence, the overpressure is constrained by the phase equilibrium pressure, regardless of the kinetic rate of dissociation, heat supply, and sediment permeability. Furthermore, we find that the timescale for buildup of pressure by dissociation is typically much larger than that for its dissipation by drainage. Consequently, the overpressure is controlled by the capillary entry thresholds, which depend on the mode of gas invasion. In low-permeability systems, fracturing is the preferred mechanism, occurring at capillary pressures lower than the entry thresholds in the undeformed sediment. Our results suggest that while large overpressures cannot be sustained by rapid dissociation in natural systems, dissociation can induce important geomechanical effects. Gas migration by fracturing provides a possible link between dissociation, sediment deformation and methane venting.

  8. An analysis of the response of Sooty Tern eggs to sonic boom overpressures.

    PubMed

    Ting, Carina; Garrelick, Joel; Bowles, Ann

    2002-01-01

    It has been proposed that sonic booms caused a mass hatching failure of Sooty Terns in the Dry Tortugas in Florida by cracking the eggshells. This paper investigates this possibility analytically, complementing previous empirical studies. The sonic boom is represented as a plane-wave excitation with an N-wave time signature. Two models for the egg are employed. The first model, intended to provide insight, consists of a spherical shell, with the embryo represented as a rigid, concentric sphere and the albumen as an acoustic fluid filling the intervening volume. The substrate is modeled as a doubling of the incident pressure. The second, numerical model includes the egg-shape geometry and air sac. More importantly, the substrate is modeled as a rigid boundary of infinite extent with acoustic diffraction included. The peak shell stress, embryo acceleration, and reactive force are predicted as a function of the peak sonic boom overpressure and compared with damage criteria from the literature. The predicted peak sonic boom overpressure necessary for egg damage is much higher than documented sonic boom overpressures, even for extraordinary operational conditions. Therefore, as with previous empirical studies, it is concluded that it is unlikely that sonic boom overpressures damage avian eggs.

  9. An analysis of the response of Sooty Tern eggs to sonic boom overpressures

    NASA Astrophysics Data System (ADS)

    Ting, Carina; Garrelick, Joel; Bowles, Ann

    2002-01-01

    It has been proposed that sonic booms caused a mass hatching failure of Sooty Terns in the Dry Tortugas in Florida by cracking the eggshells. This paper investigates this possibility analytically, complementing previous empirical studies. The sonic boom is represented as a plane-wave excitation with an N-wave time signature. Two models for the egg are employed. The first model, intended to provide insight, consists of a spherical shell, with the embryo represented as a rigid, concentric sphere and the albumen as an acoustic fluid filling the intervening volume. The substrate is modeled as a doubling of the incident pressure. The second, numerical model includes the egg-shape geometry and air sac. More importantly, the substrate is modeled as a rigid boundary of infinite extent with acoustic diffraction included. The peak shell stress, embryo acceleration, and reactive force are predicted as a function of the peak sonic boom overpressure and compared with damage criteria from the literature. The predicted peak sonic boom overpressure necessary for egg damage is much higher than documented sonic boom overpressures, even for extraordinary operational conditions. Therefore, as with previous empirical studies, it is concluded that it is unlikely that sonic boom overpressures damage avian eggs.

  10. Up-regulation of reactivity and survival genes in astrocytes after exposure to short duration overpressure.

    PubMed

    Vandevord, Pamela J; Leung, Lai Yee; Hardy, Warren; Mason, Matthew; Yang, King H; King, Albert I

    2008-04-04

    Gurdjian et al. proposed decades ago that pressure gradients played a major factor in neuronal injury due to impact. In the late 1950s, their experiments on concussion demonstrated that the principal factor in the production of concussion in animals was the sudden increase of intracranial pressure accompanying head injury. They reported the increase in pressure severity correlated with an increase in 'altered cells' resulting in animal death. More recently, Hardy et al. (2006) demonstrated the presence of transient pressure pulses with impact conditions. These studies indicate that short duration overpressure should be further examined as a mechanism of traumatic brain injury (TBI). In the present study, we designed and fabricated a barochamber that simulated overpressure noted in various head injury studies. We tested the effect of overpressure on astrocytes. Expressions of apoptotic, reactivity and survival genes were examined at 24, 48 and 72 h post-overpressure exposure. At 24 h, we found elevated levels of reactivity and survival gene expression. By 48 h, a decreased expression of apoptotic genes was demonstrated. This study reinforces the hypothesis that transient pressure acts to instigate the cellular response displayed following TBI.

  11. Prediction of sonic boom from experimental near-field overpressure data. Volume 2: Data base construction

    NASA Technical Reports Server (NTRS)

    Glatt, C. R.; Reiners, S. J.; Hague, D. S.

    1975-01-01

    A computerized method for storing, updating and augmenting experimentally determined overpressure signatures has been developed. A data base of pressure signatures for a shuttle type vehicle has been stored. The data base has been used for the prediction of sonic boom with the program described in Volume I.

  12. Antifungal metabolites from the roots of Diospyros virginiana by overpressure layer chromatography

    USDA-ARS?s Scientific Manuscript database

    A preparative overpressure layer chromatography (OPLC) method was successfully used for the separation of two new natural compounds, 4-hydroxy-5,6-dimethoxy-2-naphthaldehyde (1) and (Delta)12,13-20,29-dihydrobetulin (2) together with nine known compounds including 7-methyl-juglone (3), diospyrin (4)...

  13. Simulated blast overpressure induces specific astrocyte injury in an ex vivo brain slice model

    PubMed Central

    Canchi, Saranya; Sarntinoranont, Malisa; Hong, Yu; Flint, Jeremy J.; Subhash, Ghatu; King, Michael A.

    2017-01-01

    Exposure to explosive blasts can produce functional debilitation in the absence of brain pathology detectable at the scale of current diagnostic imaging. Transient (ms) overpressure components of the primary blast wave are considered to be potentially damaging to the brain. Astrocytes participate in neuronal metabolic maintenance, blood–brain barrier, regulation of homeostatic environment, and tissue remodeling. Damage to astrocytes via direct physical forces has the potential to disrupt local and global functioning of neuronal tissue. Using an ex vivo brain slice model, we tested the hypothesis that viable astrocytes within the slice could be injured simply by transit of a single blast wave consisting of overpressure alone. A polymer split Hopkinson pressure bar (PSHPB) system was adapted to impart a single positive pressure transient with a comparable magnitude to those that might be present inside the head. A custom built test chamber housing the brain tissue slice incorporated revised design elements to reduce fluid space and promote transit of a uniform planar waveform. Confocal microscopy, stereology, and morphometry of glial fibrillary acidic protein (GFAP) immunoreactivity revealed that two distinct astrocyte injury profiles were identified across a 4 hr post-test survival interval: (a) presumed conventional astrogliosis characterized by enhanced GFAP immunofluorescence intensity without significant change in tissue area fraction and (b) a process comparable to clasmatodendrosis, an autophagic degradation of distal processes that has not been previously associated with blast induced neurotrauma. Analysis of astrocyte branching revealed early, sustained, and progressive differences distinct from the effects of slice incubation absent overpressure testing. Astrocyte vulnerability to overpressure transients indicates a potential for significant involvement in brain blast pathology and emergent dysfunction. The testing platform can isolate overpressure injury

  14. Simulated blast overpressure induces specific astrocyte injury in an ex vivo brain slice model.

    PubMed

    Canchi, Saranya; Sarntinoranont, Malisa; Hong, Yu; Flint, Jeremy J; Subhash, Ghatu; King, Michael A

    2017-01-01

    Exposure to explosive blasts can produce functional debilitation in the absence of brain pathology detectable at the scale of current diagnostic imaging. Transient (ms) overpressure components of the primary blast wave are considered to be potentially damaging to the brain. Astrocytes participate in neuronal metabolic maintenance, blood-brain barrier, regulation of homeostatic environment, and tissue remodeling. Damage to astrocytes via direct physical forces has the potential to disrupt local and global functioning of neuronal tissue. Using an ex vivo brain slice model, we tested the hypothesis that viable astrocytes within the slice could be injured simply by transit of a single blast wave consisting of overpressure alone. A polymer split Hopkinson pressure bar (PSHPB) system was adapted to impart a single positive pressure transient with a comparable magnitude to those that might be present inside the head. A custom built test chamber housing the brain tissue slice incorporated revised design elements to reduce fluid space and promote transit of a uniform planar waveform. Confocal microscopy, stereology, and morphometry of glial fibrillary acidic protein (GFAP) immunoreactivity revealed that two distinct astrocyte injury profiles were identified across a 4 hr post-test survival interval: (a) presumed conventional astrogliosis characterized by enhanced GFAP immunofluorescence intensity without significant change in tissue area fraction and (b) a process comparable to clasmatodendrosis, an autophagic degradation of distal processes that has not been previously associated with blast induced neurotrauma. Analysis of astrocyte branching revealed early, sustained, and progressive differences distinct from the effects of slice incubation absent overpressure testing. Astrocyte vulnerability to overpressure transients indicates a potential for significant involvement in brain blast pathology and emergent dysfunction. The testing platform can isolate overpressure injury

  15. Seismic detection of overpressuring and fracturing: An example from the Qaidam Basin, People's Republic of China

    SciTech Connect

    Paul, R.J. )

    1993-10-01

    Shallow hydrocarbon reserves were discovered in 1959 in the Nan Yi Shan structure located near the western corner of the Qaidam Basin. The first successful deep well encountered an overpressured zone at 3,000 m that resulted in a well blowout. To improve the structural definition of the field and delineate the overpressured layer a 3-D seismic survey was conducted. A region of anomalous seismic time sag associated with fracturing and small quantities of oil and gas was identified on the northwest plunging nose of the Nan Yi Shan anticline. The distribution of stacking (NMO) velocities in this region was regarded as abnormal; stacking velocities derived on the steeply dipping flanks adjacent to the sag anomaly were found to be slower than those on the shallower crest. Ray-trace modeling of a buried low-velocity anomaly provided a possible geometric solution to explain both the time variant nature of the sag and the unusual stacking velocity signature associated with it. A significant difference in seismic and sonic travel times was also observed for wells that penetrated the sag region and was attributed to localized fracturing. In a deeper interval, seismic amplitudes were used to identify gas-saturated fracture porosity and to describe the spatial limits of overpressuring within a thin-bed reservoir. Wells drilled through high-amplitude anomalies encountered overpressuring, those drilled in a region of moderate seismic amplitude tested significant quantities of gas, and wells located outside the region of good coherent signal encountered poor or no hydrocarbon shows. These results demonstrate that with good quality seismic data and sufficient lateral and vertical resolution, thin fractured hydrocarbon-bearing reservoirs can be delineated and overpressure zones identified.

  16. Overpressure wave interaction with droplets: time resolved measurements by laser shadowscopy

    NASA Astrophysics Data System (ADS)

    Slangen, Pierre; Aprin, Laurent; Heymes, Frédéric; Munier, Laurent; Lapébie, Emmanuel; Dusserre, Gilles

    2012-10-01

    Risk sciences involve increasingly optics applications to perform accurate analysis of critical behavior such as failures, explosions, fires. In this particular context, different area sizes are investigated under high temporal sampling rate up to 10000fps. With the improvement of light sources and optical sensors, it is now possible to cope with high spatial resolution even for time resolved measurement. The paper deals with the study of the interaction between overpressure waves, occurring in case of explosion for example, with a liquid droplet present in the vicinity of the overpressure wave. This is a typical scenario encountered in case of industrial breakdown including liquid leakage and explosions. We designed an experimental setup for the evaluation of the interaction between the overpressure wave and falling liquid droplets. A gas chamber is filled with nitrogen until breakage of the outlet rupture disk at about 4 bar. The droplets fall is controlled by an automatic syringe injector placed in the overpressure wave. The imaging system is based on laser shadowscopy. The laser source is a double cavity 15mJ- 1000Hz Nd YLF laser emitting double pulses of about 10ns at 527nm. To record the double pulse after crossing the falling droplets, the transmitted light is captured by a lasersynchronized double frame camera. Since these measurements are time-synchronized, it is then possible to know accurately the different parameters of the phenomenon, such as overpressure wave velocity, droplets diameter, and Reynolds number. Different experiments have been carried out at about 4000 doubleframe/s. The paper presents the whole experiment, the enhancements of the setup and the results for different liquid products from water to acetone.

  17. Characteristic overpressure-impulse-distance curves for vapour cloud explosions using the TNO Multi-Energy model.

    PubMed

    Díaz Alonso, Fernando; González Ferradás, Enrique; Sánchez Pérez, Juan Francisco; Miñana Aznar, Agustín; Ruiz Gimeno, José; Martínez Alonso, Jesús

    2006-09-21

    A number of models have been proposed to calculate overpressure and impulse from accidental industrial explosions. When the blast is produced by ignition of a vapour cloud, the TNO Multi-Energy model is widely used. From the curves given by this model, data are fitted to obtain equations showing the relationship between overpressure, impulse and distance. These equations, referred herein as characteristic curves, can be fitted by means of power equations, which depend on explosion energy and charge strength. Characteristic curves allow the determination of overpressure and impulse at each distance.

  18. Effects of blast overpressure on neurons and glial cells in rat organotypic hippocampal slice cultures.

    PubMed

    Miller, Anna P; Shah, Alok S; Aperi, Brandy V; Budde, Matthew D; Pintar, Frank A; Tarima, Sergey; Kurpad, Shekar N; Stemper, Brian D; Glavaski-Joksimovic, Aleksandra

    2015-01-01

    Due to recent involvement in military conflicts, and an increase in the use of explosives, there has been an escalation in the incidence of blast-induced traumatic brain injury (bTBI) among US military personnel. Having a better understanding of the cellular and molecular cascade of events in bTBI is prerequisite for the development of an effective therapy that currently is unavailable. The present study utilized organotypic hippocampal slice cultures (OHCs) exposed to blast overpressures of 150 kPa (low) and 280 kPa (high) as an in vitro bTBI model. Using this model, we further characterized the cellular effects of the blast injury. Blast-evoked cell death was visualized by a propidium iodide (PI) uptake assay as early as 2 h post-injury. Quantification of PI staining in the cornu Ammonis 1 and 3 (CA1 and CA3) and the dentate gyrus regions of the hippocampus at 2, 24, 48, and 72 h following blast exposure revealed significant time dependent effects. OHCs exposed to 150 kPa demonstrated a slow increase in cell death plateauing between 24 and 48 h, while OHCs from the high-blast group exhibited a rapid increase in cell death already at 2 h, peaking at ~24 h post-injury. Measurements of lactate dehydrogenase release into the culture medium also revealed a significant increase in cell lysis in both low- and high-blast groups compared to sham controls. OHCs were fixed at 72 h post-injury and immunostained for markers against neurons, astrocytes, and microglia. Labeling OHCs with PI, neuronal, and glial markers revealed that the blast-evoked extensive neuronal death and to a lesser extent loss of glial cells. Furthermore, our data demonstrated activation of astrocytes and microglial cells in low- and high-blasted OHCs, which reached a statistically significant difference in the high-blast group. These data confirmed that our in vitro bTBI model is a useful tool for studying cellular and molecular changes after blast exposure.

  19. Effects of Blast Overpressure on Neurons and Glial Cells in Rat Organotypic Hippocampal Slice Cultures

    PubMed Central

    Miller, Anna P.; Shah, Alok S.; Aperi, Brandy V.; Budde, Matthew D.; Pintar, Frank A.; Tarima, Sergey; Kurpad, Shekar N.; Stemper, Brian D.; Glavaski-Joksimovic, Aleksandra

    2015-01-01

    Due to recent involvement in military conflicts, and an increase in the use of explosives, there has been an escalation in the incidence of blast-induced traumatic brain injury (bTBI) among US military personnel. Having a better understanding of the cellular and molecular cascade of events in bTBI is prerequisite for the development of an effective therapy that currently is unavailable. The present study utilized organotypic hippocampal slice cultures (OHCs) exposed to blast overpressures of 150 kPa (low) and 280 kPa (high) as an in vitro bTBI model. Using this model, we further characterized the cellular effects of the blast injury. Blast-evoked cell death was visualized by a propidium iodide (PI) uptake assay as early as 2 h post-injury. Quantification of PI staining in the cornu Ammonis 1 and 3 (CA1 and CA3) and the dentate gyrus regions of the hippocampus at 2, 24, 48, and 72 h following blast exposure revealed significant time dependent effects. OHCs exposed to 150 kPa demonstrated a slow increase in cell death plateauing between 24 and 48 h, while OHCs from the high-blast group exhibited a rapid increase in cell death already at 2 h, peaking at ~24 h post-injury. Measurements of lactate dehydrogenase release into the culture medium also revealed a significant increase in cell lysis in both low- and high-blast groups compared to sham controls. OHCs were fixed at 72 h post-injury and immunostained for markers against neurons, astrocytes, and microglia. Labeling OHCs with PI, neuronal, and glial markers revealed that the blast-evoked extensive neuronal death and to a lesser extent loss of glial cells. Furthermore, our data demonstrated activation of astrocytes and microglial cells in low- and high-blasted OHCs, which reached a statistically significant difference in the high-blast group. These data confirmed that our in vitro bTBI model is a useful tool for studying cellular and molecular changes after blast exposure. PMID:25729377

  20. Overpressure Caused by the Smectite Dehydration Influences on the triggering of fault slip

    NASA Astrophysics Data System (ADS)

    Lin, Wen-Sheng; Liu, Chen-Wuing; Chang, Han-Yuan

    2015-04-01

    Overpressure, which is pore fluid pressure higher than hydrostatic pressure, is observed in numerous mechanical processes along major faults. Many investigations currently show that the pore fluid pressure has been observed to influence the thrust fault strength and slip behavior and updip limit of the seismogenic zone. Clay dehydration is one key control on overpressure generation under undrained condition in thermal pressurization processes. Increasing pressure and temperature with depth depending on the local geological setting and conditions can cause clay dehydration which has been proposed as an explanation for the generation of overpressure. However, study about the effect of excess pore pressure caused by clay dehydration on the triggering of earthquake is seldom addressed in Taiwan. In fault zones like the Chelungpu Fault, clay minerals are abundant in the fault gouge. Therefore, to quantify the effect of overpressure caused by clay dehydration on the triggering of earthquake under undrained condition, we adopt the chemical thermodynamic model and chemical kinetic model to calculate the amount of water expelled from clay dehydration; derive the three-dimensional governing equation of groundwater flow with clay dehydration varied with pressure and temperature; follow the Coulomb-Mohr frictional failure model of earthquake occurrence to evaluate the influence of the pore pressure on the change of effective Coulomb stress. Finally, development of numerical model to simulate the effect of excess pore pressure caused by clay dehydration on the coulomb failure stress coupled thermal-hydraulic-mechanical-chemical has been performed. Moreover, field application with numerical model to quantify analysis of the effect of overpressure caused by clay dehydration on the triggering of earthquake has been progressed. Coulomb stress increases of ≥0.01 MPa have been shown to be associated with seismicity rate increase and in many cases triggering earthquakes. The results

  1. A Wireless Lingual Feedback Device to Reduce Overpressures in Seated Posture: A Feasibility Study

    PubMed Central

    Chenu, Olivier; Vuillerme, Nicolas; Demongeot, Jacques; Payan, Yohan

    2009-01-01

    Background Pressure sores are localized injuries to the skin and underlying tissues and are mainly resulting from overpressure. Paraplegic peoples are particularly subjects to pressure sores because of long-time seated postures and sensory deprivation at the lower limbs. Methodology/Principal Findings Here we report outcomes of a feasibility trial involving a biofeedback system aimed at reducing buttock overpressure whilst an individual is seated. The system consists of (1) pressure sensors, (2) a laptop coupling sensors and actuator (3) a wireless Tongue Display Unit (TDU) consisting of a circuit embedded in a dental retainer with electrodes put in contact with the tongue. The principle consists in (1) detecting overpressures in people who are seated over long periods of time, (2) estimating a postural change that could reduce these overpressures and (3) communicating this change through directional information transmitted by the TDU.Twenty-four healthy subjects voluntarily participated in this study. Twelve healthy subjects initially formed the experimental group (EG) and were seated on a chair with the wireless TDU inside their mouth. They were asked to follow TDU orders that were randomly spread throughout the session. They were evaluated during two experimental sessions during which 20 electro-stimulations were sent. Twelve other subjects, added retrospectively, formed the control group (CG). These subjects participated in one session of the same experiment without any biofeedback.Three dependent variables were computed: (1) the ability of subjects to reach target posture (EG versus CG), (2) high pressure reductions after a biofeedback (EG versus CG) and (3) the level of these reductions relative to their initial values (EG only). Results show (1) that EG reached target postures in 90.2% of the trials, against 5,3% in the CG, (2) a significant reduction in overpressures in the EG compared to the CG and (3), for the EG, that the higher the initial pressures

  2. Identification of low-overpressure interval and its implication to hydrocarbon migration: Case study in the Yanan sag of the Qiongdongnan Basin, South China Sea.

    PubMed

    Xu, Qinghai; Shi, Wanzhong; Xie, Yuhong; Wang, Zhenfeng; Li, Xusheng; Tong, Chuanxin

    2017-01-01

    The Qiongdongnan Basin is a strongly overpressured basin with the maximum pressure coefficient (the ratio of the actual pore pressure versus hydrostatic pressure at the same depth) over 2.27. However, there exists a widespread low-overpressure interval between the strong overpressure intervals in the Yanan Sag of western basin. The mechanisms of the low-overpressure interval are not well understood. Three main approaches, pore pressure test data and well-log analysis, pressure prediction based on the relationship between the deviation of the velocity and the pressure coefficients, and numerical modeling, were employed to illustrate the distribution and evolution of the low-overpressure interval. And we analyzed and explained the phenomenon of the low-overpressure interval that is both underlain and overlain by high overpressure internal. The low-overpressure interval between the strong overpressure intervals can be identified and modelled by drilling data of P-wave sonic and the mud weight, and the numerical modeling using the PetroMod software. Results show that the low-overpressure interval is mainly composed of sandstone sediments. The porosities of sandstone in the low-overpressure interval primarily range from 15%-20%, and the permeabilities range from 10-100 md. Analysis of the geochemical parameters of C1, iC4/nC4, ΔR3, and numerical modeling shows that oil and gas migrated upward into the sandstone in the low-overpressure interval, and then migrated along the sandstone of low-overpressure interval into the Yacheng uplift. The low-overpressure both underlain and overlain by overpressure resulted from the fluids migrating along the sandstones in the low-overpressure interval into the Yacheng uplift since 1.9Ma. The mudstone in the strong overpressure interval is good cap overlain the sandstone of low-overpressure interval, therefore up-dip pinchouts or isolated sandstone in the low-overpressure interval locating the migration path of oil and gas are good

  3. Flight Demonstration Of Low Overpressure N-Wave Sonic Booms And Evanescent Waves

    NASA Astrophysics Data System (ADS)

    Haering, Edward A.; Smolka, James W.; Murray, James E.; Plotkin, Kenneth J.

    2006-05-01

    The recent flight demonstration of shaped sonic booms shows the potential for quiet overland supersonic flight, which could revolutionize air transport. To successfully design quiet supersonic aircraft, the upper limit of an acceptable noise level must be determined through quantitative recording and subjective human response measurements. Past efforts have concentrated on the use of sonic boom simulators to assess human response, but simulators often cannot reproduce a realistic sonic boom sound. Until now, molecular relaxation effects on low overpressure rise time had never been compared with flight data. Supersonic flight slower than the cutoff Mach number, which generates evanescent waves, also prevents loud sonic booms from impacting the ground. The loudness of these evanescent waves can be computed, but flight measurement validation is needed. A novel flight demonstration technique that generates low overpressure N-waves using conventional military aircraft is outlined, in addition to initial quantitative flight data. As part of this demonstration, evanescent waves also will be recorded.

  4. Flight Demonstration Of Low Overpressure N-Wave Sonic Booms And Evanescent Waves

    NASA Technical Reports Server (NTRS)

    Haering, Edward A., Jr.; Smolka, James W.; Murray, James E.; Plotkin, Kenneth J.

    2005-01-01

    The recent flight demonstration of shaped sonic booms shows the potential for quiet overland supersonic flight, which could revolutionize air transport. To successfully design quiet supersonic aircraft, the upper limit of an acceptable noise level must be determined through quantitative recording and subjective human response measurements. Past efforts have concentrated on the use of sonic boom simulators to assess human response, but simulators often cannot reproduce a realistic sonic boom sound. Until now, molecular relaxation effects on low overpressure rise time had never been compared with flight data. Supersonic flight slower than the cutoff Mach number, which generates evanescent waves, also prevents loud sonic booms from impacting the ground. The loudness of these evanescent waves can be computed, but flight measurement validation is needed. A novel flight demonstration technique that generates low overpressure N-waves using conventional military aircraft is outlined, in addition to initial quantitative flight data. As part of this demonstration, evanescent waves also will be recorded.

  5. Using liquid superheating energy for a quick estimation of overpressure in BLEVEs and similar explosions.

    PubMed

    Casal, Joaquim; Salla, Josep M

    2006-10-11

    A method is proposed for the quick estimation of the peak overpressure caused by a Boiling Liquid Expanding Vapor Explosion (BLEVE) or a similar explosion. The method is based on the use of the "superheating energy" (SE), which is the difference between the specific enthalpy of the liquid at the temperature just before the explosion and the specific enthalpy of the liquid at its saturation temperature, at atmospheric pressure. The analysis performed with a set of reference substances showed that in a BLEVE or in similar explosions, the energy converted into overpressure will range between 3.5 and 14% of SE. The comparison of the values thus obtained with experimental data from the literature shows a fairly good agreement.

  6. Minimization of sonic-boom parameters in real and isothermal atmospheres. [overpressure and acoustic impedance

    NASA Technical Reports Server (NTRS)

    Darden, C. M.

    1975-01-01

    The procedure for sonic-boom minimization introduced by Seebass and George for an isothermal atmosphere was converted for use in the real atmosphere by means of the appropriate equations for sonic-boom pressure signature advance, ray-tube area, and acoustic impedance. Results of calculations using both atmospheres indicate that except for low Mach numbers or high altitudes, the isothermal atmosphere with a scale height of 7620 m (25 000 ft) gives a reasonable estimate of the values of overpressure, impulse, and characteristic overpressure obtained by using the real atmosphere. The results also show that for aircraft design studies, propagation of a known F-function, or minimization studies at low supersonic Mach numbers, the isothermal approximation is not adequate.

  7. The quantitative assessment of domino effects caused by overpressure. Part I. Probit models.

    PubMed

    Cozzani, Valerio; Salzano, Ernesto

    2004-03-19

    Accidents caused by domino effect are among the more severe that took place in the chemical and process industry. However, a well established and widely accepted methodology for the quantitative assessment of domino accidents contribution to industrial risk is still missing. Hence, available data on damage to process equipment caused by blast waves were revised in the framework of quantitative risk analysis, aiming at the quantitative assessment of domino effects caused by overpressure. Specific probit models were derived for several categories of process equipment and were compared to other literature approaches for the prediction of probability of damage of equipment loaded by overpressure. The results evidence the importance of using equipment-specific models for the probability of damage and equipment-specific damage threshold values, rather than general equipment correlation, which may lead to errors up to 500%.

  8. Intracrystalline nucleation during the post-garnet transformation under large overpressure conditions in deep subducting slabs

    NASA Astrophysics Data System (ADS)

    Nishi, Masayuki; Irifune, Tetsuo; Ohfuji, Hiroaki; Tange, Yoshinori

    2012-12-01

    The mechanism of the post-garnet transformation in natural single-crystalline pyropic garnet has been examined under large overpressure conditions of ˜31-43 GPa using the multianvil apparatus with sintered diamond anvils. Intracrystalline nucleation was found to be dominant above 35-38 GPa, while only grain-boundary nucleation is responsible at lower pressures. In addition, natural pyropic garnet transformed to a single phase of perovskite without decomposing to multiple phases above 38 GPa. Both intracrystalline nucleation and polymorphic growth of the post-garnet transformation under large overpressure conditions would strongly enhance the transformation kinetics. Consequently, the post-garnet transformation may pwroceed rapidly in the subducting slab at depths near ˜950 km, which would cause substantial rheological weakening of the subducting slab. The metastable post-garnet transformation may also cause the seismic discontinuities at a depth of 900-1080 km depth, which is indeed observed beneath some subduction zones.

  9. Shock destruction armor system

    DOEpatents

    Froeschner, Kenneth E.

    1993-01-01

    A shock destruction armor system is constructed and arranged to destroy the force of impact of a projectile by shock hydrodynamics. The armor system is designed to comprise a plurality of superimposed armor plates each preferably having a thickness less than five times the projectile's diameter and are preferably separated one-from-another by a distance at least equal to one-half of the projectile's diameter. The armor plates are effective to hydrodynamically and sequentially destroy the projectile. The armor system is particularly adapted for use on various military vehicles, such as tanks, aircraft and ships.

  10. Neurocognitive and Biomarker Evaluation of Combination mTBI from Blast Overpressure and Traumatic Stress

    DTIC Science & Technology

    2014-11-01

    ABSTRACT Mild traumatic brain injury (mTBI) and post-traumatic stress disorder (PTSD) are major medical issues for the Warfighter. The current project is...designed to evaluate the impact of mild traumatic brain injury (using blast overpressure) and the processes involved in traumatic stress (using a...response system activation. 15. SUBJECT TERMS Traumatic brain injury , post-traumatic stress disorder, blast over pressure 16. SECURITY

  11. Neurocognitive and Biomarker Evaluation of Combination mTBI from Blast Overpressure and Traumatic Stress

    DTIC Science & Technology

    2013-09-01

    traumatic brain injury (mTBI) and post-traumatic stress disorder (PTSD) are major medical issues for the Warfighter. The current project is designed...to evaluate the impact of mild traumatic brain injury (using blast overpressure) and the processes involved in traumatic stress (using a predator...brain injury (mTBI) and post-traumatic stress disorder (PTSD) are medical issues for the war fighter. Sometimes, mTBI and PTSD present a convergence

  12. Method and apparatus for suppressing ignition overpressure in solid rocket propulsion systems

    NASA Technical Reports Server (NTRS)

    Guest, S. H.; Jones, J. H. (Inventor)

    1982-01-01

    The transient overpressure wave produced upon ignition of a solid rocket booster is suppressed by providing within the launch platform, a plurality of pipes and spray heads disposed around the periphery of the exhaust gas plume near its upper end and spraying water into the upper end of the plume during ignition. A large amount of water, preferably equivalent in mass of exhaust products being ejected, is sprayed into the plume in a direction generally perpendicular to plume flow.

  13. Prediction of sonic boom from experimental near-field overpressure data. Volume 1: Method and results

    NASA Technical Reports Server (NTRS)

    Glatt, C. R.; Hague, D. S.; Reiners, S. J.

    1975-01-01

    A computerized procedure for predicting sonic boom from experimental near-field overpressure data has been developed. The procedure extrapolates near-field pressure signatures for a specified flight condition to the ground by the Thomas method. Near-field pressure signatures are interpolated from a data base of experimental pressure signatures. The program is an independently operated ODIN (Optimal Design Integration) program which obtains flight path information from other ODIN programs or from input.

  14. Structural consequences of cohesion in gravitational instabilities triggered by fluid overpressure: Analytical derivation and experimental testing

    NASA Astrophysics Data System (ADS)

    Mourgues, R.; Costa, A. C. G.; Marques, F. O.; Lacoste, A.; Hildenbrand, A.

    2016-06-01

    The critical taper theory of Coulomb wedges has been classically applied to compressive regimes (accretionary prisms/fold-and-thrust belts), and more recently to gravitational instabilities. Following the initial hypothesis of the theory, we provide an alternative expression of the exact solution for a non-cohesive wedge by considering the balance of forces applied to the external surfaces. Then, we use this approach to derive a solution for the case of cohesive wedges. We show that cohesion has conspicuous structural effects, including a minimum length required for sliding and the formation of listric faults. The stabilizing effect of cohesion is accentuated in the foremost thin domain of the wedge, defining a required Minimum Failure Length (MFL), and producing sliding of a rigid mass above the detachment. This MFL decreases with less cohesion, a smaller coefficient of internal friction, larger fluid overpressure ratio, and steeper upper and basal surfaces for the wedge. Listricity of the normal faults depends on the fluid overpressure magnitude within the wedge. For moderate fluid overpressure, normal faults are curved close to the surface, and become straight at depth. In contrast, where fluid overpressure exceeds a critical value corresponding to the fluid pressure required to destabilize the surface of a noncohesive wedge, the state of stress changes and rotates at depth. The faults are straight close to the surface and listric at depth, becoming parallel to the upper surface if the wedge is thick enough. We tested some of these structural effects of a cohesive wedge on gravitational instabilities using analogue models where cohesive material was subjected to pore-fluid pressure. The shape of the faults obtained in the models is consistent with the predictions of the theory.

  15. Role of fluid overpressures in crustal strength and the form of the brittle-ductile transition

    NASA Astrophysics Data System (ADS)

    Suppe, J.

    2014-12-01

    The classic crustal strength-depth model of Brace and Kolhstedt (1980) (see figure) based on experimental rock mechanics depends in the brittle regime on the critical assumption of linearly increasing hydrostatic pore-fluid pressures. This leads to a predicted linearly increasing brittle strength that is well established based on deep borehole stress measurements in crystalline crust. In contrast, fluid overpressures are widely documented in orogenic belts based on borehole data, seismic velocity analysis and analysis of veins, in some cases showing complex fault-valve pressure fluctuations between lithostatic and hydrostatic. Typical observed overpressure-depth relationships predict a brittle crustal strength that is approximately constant with depth in contrast with the classic model. This constant-strength behavior below the fluid-retention depth (ZFRD in figure) has been confirmed using deep borehole stress and fluid-pressure measurements (Suppe, 2014). Recent ductile-plastic modeling of disequilibrium compaction suggests that pressure solution promotes further increases in overpressure and weakening, promoting a very prolonged low-strength brittle-ductile transition. Overpressured conditions can be inferred to exist over a substantial fraction of crustal thickness, spanning the brittle-ductile transition, in several tectonic environments, most straightforwardly in shale-rich clastic sedimentary basins built to sea level on oceanic or highly thinned continental crust such as the US Gulf Coast and Niger Delta. These thick accumulations commonly deform into shale-rich plate boundary mountain belts (e.g. Bangladesh/Miyanmar, Makran, Trinidad/Barbados, Gulf of Alaska, southern Taiwan and New Zealand). There is deep geophysical evidence for near lithostatic pore-fluid pressures existing to depths of 20-30km based on Vp, Vs, Vp/Vs and Q observations. We present active examples from Taiwan and New Zealand, combining borehole data and seismic tomography.

  16. Distribution and generation of the overpressure system, Eastern Delaware Basin, Western Texas and Southern New Mexico: Discussion

    SciTech Connect

    Swarbrick, R.E.

    1995-12-01

    Luo et al. (1994) discussed the distribution and possible origin of a three-fold pressure system in the eastern Delaware basin. The pressure data presented in their pressure vs. depth plots were exclusively derived from drill-stem tests (DSTs), although they contend that the overpressure is also confirmed from well log responses. The paper is weakened by incorrect sourece of pressure data from DSTs, and also by poor understanding and inadequate review of the basis for overpressure generation in sedimentary basins.

  17. An Evaluation of the Compressive Properties of Helmet Pads Pre- and Post-Shock Wave Overpressure Exposure

    DTIC Science & Technology

    2015-08-14

    COMPRESSIVE PROPERTIES OF HELMET PADS PRE - AND POST- SHOCK WAVE OVERPRESSURE EXPOSURE by Marina Carboni Xiaolin Zhen Barry DeCristofano and... PRE - AND POST-SHOCK WAVE OVERPRESSURE EXPOSURE 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Marina Carboni...release; distribution is unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT This report documents a study of the compressive properties between pre - and

  18. Analysis of over-pressure mechanisms in the Uinta Basin, Utah

    SciTech Connect

    McPherson, B.; Bredehoeft, J.

    1995-03-01

    Extremely high pore fluid pressures exist in the area of the Altamount/Bluebell oil field in the Uinta basin, Utah. We discuss two possible mechanisms for the cause of these over-pressures in this paper: (1) compaction disequilibrium, and (2) conversion of kerogen to liquid hydrocarbon (oil). Compaction disequilibrium occurs during periods of rapid sedimentation. If the permeability of deeply buried strata is low, then connate water within the rock matrix does not escape rapidly enough as compaction occurs; as sedimentary deposition continues, high pore fluid pressures develop. Conversion of solid kerogen to a liquid generates both a liquid and additional pore space for the liquid to occupy. If the volume of the liquid generated is just sufficient to fill the pore space generated, then there will be no accompanying effect on the pore pressure. If the liquid is less dense than the solid it replaces, then there is more liquid than pore space created; pore pressure will increase, causing flow away from the area of the reaction. Pore pressure is a sensitive measure of the balance between hydrocarbon generation and expulsion from the source into adjacent strata. If high pore pressures exist only where source rocks are thought to be generating oil, then kerogen conversion is a likely over-pressure mechanism. However, if over-pressures are found in low-permeability strata regardless of source rock proximity, then sedimentary compaction is probably a more dominant mechanism.

  19. Development of a multimodal blast sensor for measurement of head impact and over-pressurization exposure.

    PubMed

    Chu, Jeffrey J; Beckwith, Jonathan G; Leonard, Daniel S; Paye, Corey M; Greenwald, Richard M

    2012-01-01

    It is estimated that 10-20% of United States soldiers returning from Operation Iraqi Freedom (OIF) and Operation Enduring Freedom (OEF) have suffered at least one instance of blast-induced traumatic brain injury (bTBI) with many reporting persistent symptomology and long-term effects. This variation in blast response may be related to the complexity of blast waves and the many mechanisms of injury, including over-pressurization due to the shock wave and potential for blunt impacts to the head from shrapnel or from other indirect impacts (e.g., building, ground, and vehicle). To help differentiate the effects of primary, secondary, and tertiary effects of blast, a custom sensor was developed to simultaneously measure over-pressurization and blunt impact. Moreover, a custom, complementary filter was designed to differentiate the measurements of blunt (low-frequency bandwidth) from over-pressurization (high-frequency bandwidth). The custom sensor was evaluated in the laboratory using a shock tube to simulate shock waves and a drop fixture to simulate head impacts. Both bare sensors and sensor embedded within an ACH helmet coupon were compared to laboratory reference transducers under multiple loading conditions (n = 5) and trials at each condition (n = 3). For all comparative measures, peak magnitude, peak impulse, and cross-correlation measures, R (2) values, were greater than 0.900 indicating excellent agreement of peak measurements and time-series comparisons with laboratory measures.

  20. Lateral variations of subsalt overpressure buildup in the Gulf of Mexico

    SciTech Connect

    Malloy, S.; Petersen, K.; Lerche, I.; Lowrie, A.

    1996-09-01

    The confining pressure exerted by the prograding Tertiary clastic wedge has caused extensive salt deformation in the Gulf of Mexico. The high rates of lateral salt motion from the Louisiana shelf break to the Sigsbee Escarpment are expected to have significant impact on the dynamic evolution of the surrounding sedimentary formations. The evolution of fluid pressure in supra and subsalt sediments has been modeled in a series of pseudo-wells along a profile intersecting numerous salt sheets and structures offshore Louisiana. Based upon the estimated rates of salt movement, the timing can be determined for insertion/depletion of salt in the sediments as the salt has moved through, and by, sediments on its way basinward. An execution of a series of I-D fluid/flow compaction models has enabled estimation of the spatial variation in overpressure build-up with time. The quantitative behaviors suggest that the speed of lateral salt insertion and the thickness of the salt are the main factors, causing anomalous overpressure build-up. A quantification of the dynamic behaviors is significant when modeling the timing of potential trapping of hydrocarbons beneath salt sheets and of the sub-salt overpressure to be expected in sub-salt drilling.

  1. Overpressure protection of multiphase oil and gas production flowlines in flat or hilly terrain

    SciTech Connect

    Greaney, P.K.

    1997-05-01

    Long flowlines networking multiple wells to a central facility require overpressure protection if they are incapable of withstanding the maximum shut-in wellhead pressure and if a flowline valve at the central facility can be closed. A main component of this overpressure protection system is a relief valve or set of relief valves on the flowline at the central facility. The relief valves should have set pressures and large enough orifice areas so that no section of the flowline network becomes overpressured, especially the section most remote from the central facility. At the remote section, the pressure is significantly higher than the pressure at the relief valves at the central production facility. Proper application of multiphase hydraulic calculations is critical in determining the relationship between the central facility pressure (relief valve pressure) and the pressure at the remote well during a relief situation. Horizontal flowlines are relatively easy to analyze, but long flowlines in hilly terrain with significant upflow and downflow sections complicate the hydraulic analysis. This paper presents a methodology for determining the relief valve set pressure and orifice area for both flat horizontal flowlines and flowlines in hilly terrain. The methodology consists of simplifying the analysis by substituting worst case steady-state solutions for full transient solutions and by demonstrating that the steady-state solutions are more conservative than the transient ones.

  2. Overpressurized fluids drive microseismic swarm activity around Mt. Ontake volcano, Japan

    NASA Astrophysics Data System (ADS)

    Terakawa, Toshiko

    2017-06-01

    Microseismic swarm activity has taken place since 1976 around Mt. Ontake, the second highest stratovolcano in Japan. This activity is thought to be linked to high pore-fluid pressure in the vicinity of the volcano. We analyzed well-constrained focal mechanism solutions of microseismicity to re-estimate the 3-D pore-fluid pressure field driving vigorous swarm activity around Mt. Ontake. Pore-fluid pressures were measured by mapping earthquake focal mechanisms on the 3-D Mohr diagram for the regional stress field with high resolutions of 2-5 km. The assumption of the reference stress pattern can cause modeling errors in measurements of pore-fluid pressure. To remove the effect, we statistically evaluated the estimation errors of the regional stress field and included these errors in the analysis. We detected an overpressurized fluid reservoir with a peak of about 10-30 MPa in the east flank of Mt. Ontake, where microseismic swarm activity has been vigorous for the last two decades. The level of pore-fluid pressure was maintained for at least 5 years after 2009. This finding indicates that there are some interactions between the intensive swarm activity and overpressurized fluids: the swarm activity has been driven by overpressurized fluids, whereas pore-fluid pressures have been suppressed by the swarm activity.[Figure not available: see fulltext.

  3. Effect of host-rock rheology on dyke shape, thickness and magma overpressure

    NASA Astrophysics Data System (ADS)

    Vachon, Rémi; Hieronymus, Christoph F.

    2017-03-01

    The size and thickness of dykes is of fundamental importance for volcano dynamics because dykes are the primary path for magma transport, and because large numbers of dykes often comprise a major proportion of the volcanic edifice and of the underlying crust. Standard elastic models predict dyke geometry to be elliptic in cross-section for constant overpressure and uniform host-rock properties, whereas observations show that dyke thickness is typically more nearly constant with a sharp taper at the ends. Moreover, the predicted overpressures required to inflate dykes in a purely elastic medium are often significantly higher (>150 MPa and up to 2 GPa) than those estimated by other means (about 1-50 MPa). In this study, we use 2-D finite element models to test whether other host-rock rheologies lead to more realistic dyke shapes and overpressures. We examine three different rheologies, each of which is affected by the presence of the dyke itself: (1) elasticity with reduced moduli in regions of low pressure or tension; (2) elastoplasticity with plastic failure in the high-stress regions surrounding the dyke tips; (3) viscoelasticity with a viscosity decrease due to heating by the dyke. We use rheological parameters obtained from laboratory experiments whenever possible, and assume static conditions for the final dyke shape. We find that all three rheologies tend to make the dyke more rectangular relative to the elliptical dykes of the linearly elastic models. The change in shape is due to enhanced deformation in the high-stress zone surrounding the dyke tip. We also find that the overpressure required to inflate an initially thin dyke to a given thickness is reduced for all three rheologies. The greatest decrease in overpressure by a factor of about 0.1 is observed for the elastoplastic model, and for the viscoelastic model if the dyke intrudes into moderately pre-heated host-rock. We discuss our results with respect to dyke observations from Rum Island (Scotland

  4. Exposure to sublethal blast overpressure reduces the food intake and exercise performance of rats.

    PubMed

    Bauman, R A; Elsayed, N; Petras, J M; Widholm, J

    1997-07-25

    Exposure to blast overpressure can typically inflict generalized damage on major organ systems, especially gas-containing organs such as the lungs and the gastrointestinal tract. The purpose of the present study was to use rat's food intake and exercise wheel running as behavioral correlates of the perhaps more subtle damage to these organ systems induced by sublethal blast overpressure. Toward this end, all rats were exposed to a 12-h light/dark cycle and food was available only in the dark period. Prior to exposure, rats in the (E)xercise group were required to execute five rotations of an activity wheel for a food pellet; wheel turns that occurred at times other than when a rat was feeding were recorded separately and labeled exercise running. In the (S)edentary and (A)nesthesia groups, wheel running was not possible and rats were required to execute five leverpresses for a single pellet. A compressed air-driven shock tube was used to expose rats to a supra-atmospheric wave of air pressure. The tube was separated into two sections by a polyester membrane, the thickness of which determined peak and duration of overpressure. All rats were anesthetized with 50 mg/kg of phenobarbital. After reaching a deep plane of anesthesia, they were individually tied in a stockinet across one end of the shock tube. In preliminary tests, the membrane thickness was 1000 (A)ngstroms and rats in Group L(ethality) were exposed to a 129 kPa (peak amplitude) wave of overpressure. Three of six rats survived exposure to this peak pressure; pathology was evident in the lungs and gastrointestinal tract of all non-survivors. Rats in Groups E and S were tested with a 500 A membrane, which resulted in an 83 kPa peak amplitude. All rats survived exposure to this lower peak pressure. On the day of exposure to blast, the relative reduction of intake during the first 3 h of the dark period was significantly greater for Group E than for Groups S and A; the intake of Groups E and S remained reduced

  5. Effect of host-rock rheology on dyke shape, thickness, and magma overpressure.

    NASA Astrophysics Data System (ADS)

    Vachon, Rémi; Hieronymus, Christoph F.

    2016-12-01

    The size and thickness of dykes is of fundamental importance for volcano dynamics because dykes are the primary path for magma transport, and because large numbers of dykes often comprise a major proportion of the volcanic edifice and of the underlying crust. Standard elastic models predict dyke geometry to be elliptic in cross-section for constant overpressure and uniform host-rock properties, whereas observations show that dyke thickness is typically more nearly constant with a sharp taper at the ends. Moreover, the predicted overpressures required to inflate dykes in a purely elastic medium are often significantly higher (>150 MPa and up to 2 GPa) than those estimated by other means (about 1-50 MPa). In this study, we use two-dimensional finite element models to test whether other host-rock rheologies lead to more realistic dyke shapes and overpressures. We examine 3 different rheologies, each of which is affected by the presence of the dyke itself: (1) elasticity with reduced moduli in regions of low pressure or tension; (2) elasto-plasticity with plastic failure in the high-stress regions surrounding the dyke tips; (3) visco-elasticity with a viscosity decrease due to heating by the dyke. We use rheological parameters obtained from laboratory experiments whenever possible, and assume static conditions for the final dyke shape. We find that all 3 rheologies tend to make the dyke more rectangular relative to the elliptical dykes of the linearly elastic models. The change in shape is due to enhanced deformation in the high-stress zone surrounding the dyke tip. We also find that the overpressure required to inflate an initially thin dyke to a given thickness is reduced for all 3 rheologies. The greatest decrease in overpressure by a factor of about 0.1 is observed for the elasto-plastic model, and for the visco-elastic model if the dyke intrudes into moderately pre-heated host-rock. We discuss our results with respect to dyke observations from Rum Island (Scotland

  6. Climatology of destructive hailstorms in Brazil

    NASA Astrophysics Data System (ADS)

    Martins, Jorge A.; Brand, Veronika S.; Capucim, Mauricio N.; Felix, Rafael R.; Martins, Leila D.; Freitas, Edmilson D.; Gonçalves, Fabio L. T.; Hallak, Ricardo; Dias, Maria A. F. Silva; Cecil, Daniel J.

    2017-02-01

    Hail is considered to be among the most complex extreme weather phenomena of the atmosphere. Every year, notably in the southern Brazilian States, destructive hailstorms result in serious economic losses and cause a great social impact destroying crops, homes, medical facilities and schools. The aim of this study is to document the spatial, annual, and diurnal variation in destructive hailstorm frequency during a 22 year period from 1991 to 2012 in Brazil. The analysis is based on a collection of reports released by the Brazilian National Civil Protection Secretariat - SEDEC. Based on reports of emergency assistance given to the population affected by a disaster, the information discussed in this work is assumed as representative only of destructive hailstorms. The analysis reveals a large spatial variability, with the majority of hailstorm occurrences distributed in the three southernmost Brazilian States. Within those states, the number of hail reports was observed to increase with increasing population density in rural areas. Hailstorms were reported most often in the late afternoon and evening of the winter/spring transition, in agreement with a few other areas in the subtropics with available studies, but different from the majority of studies for temperate zones, which suggest spring/summer as the hail season. Although the results show some discrepancies compared to satellite hail signatures, the findings of this work confirm that southern Brazil is a region prone to the development of strong convective storms, with high annual numbers of destructive hail events.

  7. How can fluid overpressures be developed and maintained in crustal fault zones ?

    NASA Astrophysics Data System (ADS)

    LECLÈRE, H.; Cappa, F.; Faulkner, D. R.; Armitage, P. J.; Blake, O. O.; Fabbri, O.

    2013-12-01

    The presence of fluid overpressure in crustal fault zones is known to play a key role on the stability of faults and it has often been invoked to explain the triggering of earthquakes and the apparent weakness of misoriented faults. However, the mechanisms allowing the development and maintenance of fluid overpressures in fault remain unresolved. We investigate how fluid overpressures can be developed and maintained in complex fault zones with hydraulic and elastic heterogeneities. Here we address this question combining geological observations, laboratory experiments and hydromechanical models of an active crustal fault zone in the Ubaye-Argentera area (southeastern France). The fault zone studied is located in the Argentera external crystalline massif and is connected to regional NW-SE steeply-dipping dextral strike-slip faults with an offset of several kilometers. The fault zone cuts through migmatitic gneisses composed of quartz, K-feldspar, plagioclase, biotite and muscovite. It exposes several anastomosing core zones surrounded by damage zones with a pluri-decametric total width. The core zones are made up of centimetric to pluridecimetric phyllosilicate-rich gouge layers while the damage zones are composed of pluri-metric phyllonitic rock derived from mylonite. The determination of fault structure in the field and its hydraulic and mechanical properties in the lab are key aspects to improve our understanding of the role of fluids in fault mechanics and earthquake triggering. Here, the permeability and elastic moduli of the host rock, damage zone and fault core were measured from natural plugs with a diameter of 20 mm and lengths between 26 to 51 mm, using a high-pressure hydrostatic fluid-flow apparatus. Measurements were made with confining pressures ranging from 30 to 210 MPa and using argon pore fluid pressure of 20 MPa. Data show a reduction of the permeability values of one order of magnitude between host rock and fault damage zone and a decrease of 50

  8. Tank 48 - Chemical Destruction

    SciTech Connect

    Simner, Steven P.; Aponte, Celia I.; Brass, Earl A.

    2013-01-09

    Small tank copper-catalyzed peroxide oxidation (CCPO) is a potentially viable technology to facilitate the destruction of tetraphenylborate (TPB) organic solids contained within the Tank 48H waste at the Savannah River Site (SRS). A maturation strategy was created that identified a number of near-term development activities required to determine the viability of the CCPO process, and subsequent disposition of the CCPO effluent. Critical activities included laboratory-scale validation of the process and identification of forward transfer paths for the CCPO effluent. The technical documentation and the successful application of the CCPO process on simulated Tank 48 waste confirm that the CCPO process is a viable process for the disposition of the Tank 48 contents.

  9. Dust Formation and Destruction

    NASA Astrophysics Data System (ADS)

    Wiebe, Dmitry

    Recent infrared and sub-millimeter observations have opened up a new window in dust evolution studies. High angular resolution of Spitzer and Herschel space telescopes from near to far-infrared wavelengths allows observing dust emission in galactic and extragalactic star-forming complexes, covering a broad range of metallicities, radiation field properties, etc. A wide-scale picture of dust evolution starts to arise from these observations. In my contribution I will try to cover major recent advances in studies of dust formation and destruction, including such topics as a diverse role of supernovae in dust evolution, possibility of dust formation and/or growth in molecular clouds, and VSG and PAH evolution in HII regions and complexes.

  10. Experimental study of hydraulic ram effects on a liquid storage tank: Analysis of overpressure and cavitation induced by a high-speed projectile.

    PubMed

    Lecysyn, Nicolas; Bony-Dandrieux, Aurélia; Aprin, Laurent; Heymes, Frédéric; Slangen, Pierre; Dusserre, Gilles; Munier, Laurent; Le Gallic, Christian

    2010-06-15

    This work is part of a project for evaluating catastrophic tank failures caused by impacts with a high-speed solid body. Previous studies on shock overpressure and drag events have provided analytical predictions, but they are not sufficient to explain ejection of liquid from the tank. This study focuses on the hydrodynamic behavior of the liquid after collision to explain subsequent ejection of liquid. The study is characterized by use of high-velocity projectiles and analysis of projectile dynamics in terms of energy loss to tank contents. New tests were performed at two projectile velocities (963 and 1255 m s(-1)) and over a range of viscosities (from 1 to 23.66 mPa s) of the target liquid. Based on data obtained from a high-speed video recorder, a phenomenological description is proposed for the evolution of intense pressure waves and cavitation in the target liquids.

  11. Shock destruction armor system

    SciTech Connect

    Froeschner, K.E.

    1993-05-25

    A shock destruction armor system mounted in a vertical relationship on an external surface of a vehicle for destroying the force of impact of an incoming projectile having a length, L, equal to an aspect ratio, m, times its diameter, D, said armor system is described comprising: armor plate means, comprising a plurality of substantially vertical super-imposed armor plates secured at only one edge thereof to said vehicle, each of said armor plates having a predetermined thickness and separated one-from another by a predetermined distance, said thickness of each of said armor plates progressively increasing from a frontal armor plate, adapted to receive the force of impact of an incoming projectile, to a last armor plate thereof, said distance between said armor plates progressively increasing from a first distance between said frontal armor plate and its next-following armor plate through a last distance between said last armor plate and its next-preceding armor plate, for hydrodynamically and sequentially at least substantially destroying an incoming projectile impacting a first of said armor plates, and for inducing debris generated from the explosion on an area of impact on the first armor plate to egress from such area prior to impact of such an incoming projectile on the next-following armor plate.

  12. Internal triggering of volcanic eruptions: tracking overpressure regimes for giant magma bodies

    NASA Astrophysics Data System (ADS)

    Tramontano, Samantha; Gualda, Guilherme A. R.; Ghiorso, Mark S.

    2017-08-01

    Understanding silicic eruption triggers is paramount for deciphering explosive volcanism and its potential societal hazards. Here, we use phase equilibria modeling to determine the potential role of internal triggering - wherein magmas naturally evolve to a state in which eruption is inevitable - in rhyolitic magma bodies. Whole-rock compositions from five large to super-sized rhyolitic deposits are modeled using rhyolite-MELTS. By running simulations with varying water contents, we can track crystallization and bubble exsolution during magma solidification. We use simulations with variable enthalpy and fixed pressure for the five compositions. The interplay between bubble exsolution and crystallization can lead to an increase in the system volume, which can lead to magma overpressurization. We find that internal triggering is possible for high-silica rhyolite magmas crystallizing at pressures below 300 MPa (<11 km depth in the crust), revealing a window of eruptibility within the upper crust from which high-silica eruptions emanate. At higher pressures, the critical overpressure threshold for eruption is only reached once crystallinities are high, >50 wt.%, which makes magma immobile - high-silica rhyolite eruptions from such depths would require external triggering, but examples are scarce or entirely absent. Calculated crystallinities at which the critical overpressure threshold is reached compare favorably with observed crystal contents in natural samples for many systems, suggesting that internal evolution plays a critical role in triggering eruptions. Systems in which fluid saturation happens late relative to crystallization or in which degassing is effective can delay or avoid internal triggering. We argue that priming by crystallization and bubble exsolution is critical for magma eruption, and external triggering serves simply as the final blow - rather than being the driving force - of explosive rhyolitic eruptions.

  13. Characterization of the Scale Model Acoustic Test Overpressure Environment using Computational Fluid Dynamics

    NASA Technical Reports Server (NTRS)

    Nielsen, Tanner; West, Jeff

    2015-01-01

    The Scale Model Acoustic Test (SMAT) is a 5% scale test of the Space Launch System (SLS), which is currently being designed at Marshall Space Flight Center (MSFC). The purpose of this test is to characterize and understand a variety of acoustic phenomena that occur during the early portions of lift off, one being the overpressure environment that develops shortly after booster ignition. The pressure waves that propagate from the mobile launcher (ML) exhaust hole are defined as the ignition overpressure (IOP), while the portion of the pressure waves that exit the duct or trench are the duct overpressure (DOP). Distinguishing the IOP and DOP in scale model test data has been difficult in past experiences and in early SMAT results, due to the effects of scaling the geometry. The speed of sound of the air and combustion gas constituents is not scaled, and therefore the SMAT pressure waves propagate at approximately the same speed as occurs in full scale. However, the SMAT geometry is twenty times smaller, allowing the pressure waves to move down the exhaust hole, through the trench and duct, and impact the vehicle model much faster than occurs at full scale. The DOP waves impact portions of the vehicle at the same time as the IOP waves, making it difficult to distinguish the different waves and fully understand the data. To better understand the SMAT data, a computational fluid dynamics (CFD) analysis was performed with a fictitious geometry that isolates the IOP and DOP. The upper and lower portions of the domain were segregated to accomplish the isolation in such a way that the flow physics were not significantly altered. The Loci/CHEM CFD software program was used to perform this analysis.

  14. An improved probit method for assessment of domino effect to chemical process equipment caused by overpressure.

    PubMed

    Mingguang, Zhang; Juncheng, Jiang

    2008-10-30

    Overpressure is one important cause of domino effect in accidents of chemical process equipments. Damage probability and relative threshold value are two necessary parameters in QRA of this phenomenon. Some simple models had been proposed based on scarce data or oversimplified assumption. Hence, more data about damage to chemical process equipments were gathered and analyzed, a quantitative relationship between damage probability and damage degrees of equipment was built, and reliable probit models were developed associated to specific category of chemical process equipments. Finally, the improvements of present models were evidenced through comparison with other models in literatures, taking into account such parameters: consistency between models and data, depth of quantitativeness in QRA.

  15. Effect of fluid overpressure on thrust wedges deformation - insight from sandbox models

    NASA Astrophysics Data System (ADS)

    Pons, A.; Mourgues, R.

    2012-04-01

    Elevated pore pressures are commonly invoked as a key factor for thrust wedges deformation. Even in the well-known and widely used critical taper model of an accretionary wedge, they are introduced as a first-order parameter. This parameter is the Hubbert-Rubey pore pressure ratio λ. Despite the fact that the importance of fluid overpressure is not discussed and that more and more field measurements focus on quantifying pressure distributions, either numerical or analogue modelers are a few to take into account fluid pressure in their modeling. In the critical taper model, fluid overpressure reduces frictional resistance at the base and many experimenters used low frictional materials to create basal detachments. But fluid overpressures also act as body forces on the whole wedge in addition to that of gravity and this second effect was never experimentally confirmed. In this work, we performed scaled experiments in which compressed air is used as the pore fluid, to understand how fluid pressure controls the first stages of thrusting. The models were built with non-cohesive sand in their upper part and glass microbeads for the décollement to insure the weakness of the detachment. Both materials have similar permeabilities and as we applied horizontally varying fluid pressureat the base of the model, the pore pressure ratio λ was almost constant in the whole wedge. We found a good match with the critical taper model predictions. Combining these experiments with an optical image correlation technique (particle imaging velocimetry - PIV), we were able to follow the strain in the model during the entire duration of the shortening. In particular, we studied the propagation of the décollement and highlighted a strong influence of the pressure ratio, λ, on the activation rate of the décollement. Indeed, higher the overpressure is, faster the propagation of the décollement is. Moreover, we found that the distance to the critical taper condition, which depends on both

  16. Far Field Overpressure from TNT Explosions: A Survey of Available Models.

    DTIC Science & Technology

    1981-04-01

    distances from TNT explosions are surveyed. Analytical and empirical models are discussed. DD , iOR,, 1473 ITIO OF INOVS S IS 0SSOLErTE UNCLASSIFIED S/N...34’\\(1) F 1/3 a / where P overpressure P a absolute atmospheric pressure R =distance W = energy released by detonation of the explosive charge, usually...is typical of the analytically based models. Calculations were carried out for three cases: a nuclear blast wave in ideal air, a nuclear blast wave

  17. Blast Overpressure Studies with Animals and Man: Biological Response to Complex Blast Waves

    DTIC Science & Technology

    1993-10-31

    enclosure produce lung injury in rabbits at one -fifth the peak overpressure required for a simple wave. 2 It was suggested that the frequency content of the...Whereas i the lung hemorrhage was confined to the right lung exclusively in the sheep exposed right-side- on to the explosion outdoors in the 3 4I U...to 4.88 x 3.05 x 2.44 m (36.3 m^3), and for D it was 3.05 x 1.52 x 2.44 m (11.3 m^3). A turbine ventilator was mounted on one of I the roof sections

  18. Component Overpressure Growth and Characterization of High Resistivity CdTe Crystals for Radiation Detectors

    SciTech Connect

    Mandal, Krishna; Kang, Sung Hoon; Choi, Michael; Wei, Jiuan; Zheng, Lili; Zhang, Hui; Jellison Jr, Gerald Earle; Groza, Michael; Burger, Arnold

    2007-01-01

    Spectrometer-grade CdTe single crystals with resistivities higher than 10{sup 9} {Omega} cm have been grown by the modified Bridgman method using zone-refined precursor materials (Cd and Te) under a Cd overpressure. The grown CdTe crystals had good charge-transport properties ({mu}{tau}{sub e} = 2 x 10{sup -3} cm{sup 2} V{sup -1}, {mu}{tau}{sub h} = 8 x 10{sup -5} cm{sup 2} V{sup -1}) and significantly reduced Te precipitates compared with crystals grown without Cd overpressure. The crystal growth conditions for the Bridgman system were optimized by computer modeling and simulation, using modified MASTRAPP program, and applied to crystal diameters of 14 mm (0.55'), 38 mm (1.5'), and 76 mm (3'). Details of the CdTe crystal growth operation, structural, electrical, and optical characterization measurements, detector fabrication, and testing using {sup 241}Am (60 keV) and {sup 137}Cs (662 keV) sources are presented.

  19. The roles of foam ceramics in suppression of gas explosion overpressure and quenching of flame propagation.

    PubMed

    Nie, Baisheng; He, Xueqiu; Zhang, Ruming; Chen, Wenxue; Zhang, Jinfeng

    2011-08-30

    In order to substantially suppress the shock waves resulting from gas explosions in coal mines as well as to reveal the mechanism of explosion flame quenching by foam ceramics, a rectangular explosion test pipe was designed, which has a 200mm × 200mm cross-section and is similar in shape to the roadways in coal mines. Explosion flame propagation characteristics in empty pipe and in the presence of Al(2)O(3) and SiC foam ceramics were experimentally investigated. To obtain direct observations, the flame propagation was photographed by a high-speed camera. Furthermore, the mechanism of foam ceramics affecting gas explosion propagation was analyzed. The results demonstrate that the foam ceramics attenuate drastically the maximal explosion overpressure by up to fifty percent; the interconnected micro-network structure of the foam ceramics contribute to quenching gas explosion flame and suppressing shock wave overpressure. These important findings hint that, if properly designed and deployed, this material is expected to be developed into a new suppression and isolation technique against multiple and continuous gas explosions that are presently a grave threat to production safety of coal mines across China and the rest of the world. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Nozzle Exit Over-Pressure and Vortex Ring Interaction in a Fully-Pulsed Jet

    NASA Astrophysics Data System (ADS)

    Krueger, Paul S.; Gharib, Morteza

    2002-11-01

    Vortex rings formed by a starting jets will stop entraining circulation and pinch off from their generating or "trailing" jet for sufficiently large piston stroke length to jet diameter ratios (L/D) [Gharib et. al., JFM, 1998]. Recent work by the authors has demonstrated that the leading vortex ring contributes more impulse per unit L/D than does the trailing jet, highlighting the significance of vortex ring pinch off for propulsive applications. The impulse advantage of the leading vortex ring is provided by nozzle exit over-pressure resulting from the acceleration of ambient fluid during ring formation. The present work extends these single-pulse results to a periodic series of starting jets, i.e., a fully-pulsed jet. Measurements were made of the time-averaged thrust of fully-pulsed jets generated using a piston-cylinder mechanism for 2 < L/D < 6 and a range of pulsing frequencies. The results indicate that vortex ring formation provides substantial nozzle exit over-pressure (and hence, thrust benefit) in the pulsed case as well, but the benefit tends to diminish with increasing frequency. Various vortex ring interactions contribute to this trend.

  1. Evaluation of overpressure prediction models for air blast above the triple point.

    PubMed

    Ehrhardt, L; Boutillier, J; Magnan, P; Deck, C; De Mezzo, S; Willinger, R; Cheinet, S

    2016-07-05

    The increase of blast exposures leads to the need for better assessment of the blast threat. Empirical models describing the blast propagation in ideal conditions as free-field or surface detonations are commonly employed, but in some configurations the ground-reflected shock should be treated explicitly. Empirical models permit the prediction of the blast characteristics with the ground-reflected shock. The present study uses some original experimental data to evaluate the accuracy of the predicted overpressure with time regarding the reflected shock characteristics. Three methods are tested. The first method, called method of images (MOI) and linearly adding a virtual ground-symmetrical source blast to the free-field blast, is quick but lacks accuracy regarding the reflected shock characteristics. The second method, based on the LOAD_BLAST_ENHANCED function of the commercial LS-DYNA framework, better captures the reflected shock compared to the MOI, but the overall differences with experimental data are of the same order of magnitude as for the MOI. An original fit is introduced, based on standard physical parameters. The accuracy of this fit on the reflected shock characteristics, and the better match with the overall overpressure time series, shows its potential as a new empirical blast predicting tool. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Role of fluid overpressures in controlling the form of crustal strength-depth profiles

    NASA Astrophysics Data System (ADS)

    Suppe, John

    2015-04-01

    The classic crustal strength-depth model of Brace and Kolhstedt (1980) based on experimental rock mechanics depends in the brittle regime on the assumption of linearly increasing hydrostatic pore-fluid pressures. This leads to a predicted linearly increasing brittle strength that is well established based on deep borehole stress measurements in crystalline crust. In contrast, fluid overpressures are widely documented in orogenic belts based on borehole data, seismic velocity analysis, modeling of seismic tremors, and analysis of veins, which in some cases show complex fault-valve pressure fluctuations between lithostatic and hydrostatic. Typical observed overpressure-depth relationships show approximately constant effective stress and therefore a pressure-dependent crustal strength that is approximately constant with depth in contrast with the classic model. This constant-strength behavior below the fluid-retention depth ZFRDhas been confirmed using deep borehole stress and fluid-pressure measurements (Suppe, 2014). The pressure-dependent strength magnitude is the strength at the fluid-retention depth, which is commonly ~50MPa or less because ZFRD is typically

  3. Flameless thermal destruction of VOCs

    SciTech Connect

    Hohl, H.M.

    1997-04-01

    A new technology controls volatile organic compounds (VOCs) emissions with high destruction efficiencies. This article describes the technology developed by Thermatrix, Inc. of San Jose, CA. The field proven flameless thermal oxidation (FTO) is capable of destroying over 99.99 percent of a wide range of organic air pollution. Topics covered include FTO technology, high destruction efficiencies, VOCs in wastewater from chemical manufacturing; refinery fugitive emissions.

  4. Pressure Effects Analysis of National Ignition Facility Capacitor Module Events

    SciTech Connect

    Brereton, S; Ma, C; Newton, M; Pastrnak, J; Price, D; Prokosch, D

    1999-11-22

    Capacitors and power conditioning systems required for the National Ignition Facility (NIF) have experienced several catastrophic failures during prototype demonstration. These events generally resulted in explosion, generating a dramatic fireball and energetic shrapnel, and thus may present a threat to the walls of the capacitor bay that houses the capacitor modules. The purpose of this paper is to evaluate the ability of the capacitor bay walls to withstand the overpressure generated by the aforementioned events. Two calculations are described in this paper. The first one was used to estimate the energy release during a fireball event and the second one was used to estimate the pressure in a capacitor module during a capacitor explosion event. Both results were then used to estimate the subsequent overpressure in the capacitor bay where these events occurred. The analysis showed that the expected capacitor bay overpressure was less than the pressure tolerance of the walls. To understand the risk of the above events in NIF, capacitor module failure probabilities were also calculated. This paper concludes with estimates of the probability of single module failure and multi-module failures based on the number of catastrophic failures in the prototype demonstration facility.

  5. Altered gene expression in cultured microglia in response to simulated blast overpressure: possible role of pulse duration.

    PubMed

    Kane, Michael J; Angoa-Pérez, Mariana; Francescutti, Dina M; Sykes, Catherine E; Briggs, Denise I; Leung, Lai Yee; VandeVord, Pamela J; Kuhn, Donald M

    2012-07-26

    Blast overpressure has long been known to cause barotrauma to air-filled organs such as lung and middle ear. However, experience in Iraq and Afghanistan is revealing that individuals exposed to explosive munitions can also suffer traumatic brain injury (TBI) even in the absence of obvious external injury. The interaction of a blast shock wave with the brain in the intact cranial vault is extremely complex making it difficult to conclude that a blast wave interacts in a direct manner with the brain to cause injury. In an attempt to "isolate" the shock wave and test its primary effects on cells, we exposed cultured microglia to simulated blast overpressure in a barochamber. Overpressures ranging from 15 to 45 psi did not change microglial Cox-2 levels or TNF-α secretion nor did they cause cell damage. Microarray analysis revealed increases in expression of a number of microglial genes relating to immune function and inflammatory responses to include Saa3, Irg1, Fas and CxCl10. All changes in gene expression were dependent on pulse duration and were independent of pressure. These results indicate that microglia are mildly activated by blast overpressure and uncover a heretofore undocumented role for pulse duration in this process.

  6. Altered Gene Expression in Cultured Microglia in Response to Simulated Blast Overpressure: Possible Role of Pulse Duration

    PubMed Central

    Kane, Michael J.; Angoa-Pérez, Mariana; Francescutti, Dina M.; Sykes, Catherine E.; Briggs, Denise I.; Leung, Lai Yee; VandeVord, Pamela J.; Kuhn, Donald M.

    2012-01-01

    Blast overpressure has long been known to cause barotrauma to air-filled organs such as lung and middle ear. However, experience in Iraq and Afghanistan is revealing that individuals exposed to explosive munitions can also suffer traumatic brain injury (TBI) even in the absence of obvious external injury. The interaction of a blast shock wave with the brain in the intact cranial vault is extremely complex making it difficult to conclude that a blast wave interacts in a direct manner with the brain to cause injury. In an attempt to “isolate” the shock wave and test its primary effects on cells, we exposed cultured microglia to simulated blast overpressure in a barochamber. Overpressures ranging from 15–45 psi did not change microglial Cox-2 levels or TNF-α secretion nor did they cause cell damage. Microarray analysis revealed increases in expression of a number of microglial genes relating to immune function and inflammatory responses to include Saa3, Irg1, Fas and CxCl10. All changes in gene expression were dependent on pulse duration and were independent of pressure. These results indicate that microglia are mildly activated by blast overpressure and uncover a heretofore undocumented role for pulse duration in this process. PMID:22698585

  7. Suppressed vitrinite reflectance in the Ferron coalbed gas fairway, central Utah: Possible influence of overpressure

    USGS Publications Warehouse

    Quick, J.C.; Tabet, D.E.

    2003-01-01

    Chemical and thermoplastic properties of coals in the Ferron coalbed methane fairway indicate that coals in the north are of higher rank than coals in the south. Measured vitrinite reflectance does not accurately show this variation of coal rank. Although vitrinite reflectance in the southern and central part of the fairway is consistent with other measures of coal rank, suppressed vitrinite reflectance is observed in the north where methane contents are relatively high. This coincidence of suppressed reflectance and relatively high coalbed methane yields may be significant. We speculate that the suppressed reflectance values result from a burial history where overpressure developed during the early stages of coalification and persisted until recent uplift and cooling; such instances may be diagnostic of prospective coalbed methane targets elsewhere. ?? 2003 Published by Elsevier B.V.

  8. Short-range, overpressure-driven methane migration in coarse-grained gas hydrate reservoirs

    SciTech Connect

    Nole, Michael; Daigle, Hugh; Cook, Ann E.; Malinverno, Alberto

    2016-08-31

    Two methane migration mechanisms have been proposed for coarse-grained gas hydrate reservoirs: short-range diffusive gas migration and long-range advective fluid transport from depth. Herein we demonstrate that short-range fluid flow due to overpressure in marine sediments is a significant additional methane transport mechanism that allows hydrate to precipitate in large quantities in thick, coarse-grained hydrate reservoirs. Two-dimensional simulations demonstrate that this migration mechanism, short-range advective transport, can supply significant amounts of dissolved gas and is unencumbered by limitations of the other two end-member mechanisms. Here, short-range advective migration can increase the amount of methane delivered to sands as compared to the slow process of diffusion, yet it is not necessarily limited by effective porosity reduction as is typical of updip advection from a deep source.

  9. Tectonic overpressure may reconcile the structural and petrological records of the Adula nappe (Central Alps)

    NASA Astrophysics Data System (ADS)

    Pleuger, Jan; Podladchikov, Yuri

    2014-05-01

    accordance with the structural record, the Adula nappe can be restored to maximum depths of up to ca. 60 km. For individual points of the Adula nappe in the restored cross section, corresponding to the sporadic occurences of (ultra)high-pressure rocks, lithostatic pressures are exceeded by petrological peak-pressure data by about 40% to 80%. Such amounts of tectonic overpressure are within the limits of theoretical considerations and numerical modelling results. For the other units comprised in the cross section, and for subsequent tectono-metamorphic stages of the Adula nappe, negligible amounts of overpressure (around 10%) are determined from the restoration. We conclude that (1) the NFP20-East cross section can be kinematically restored by using only structural data, (2) the dilemma mentioned above can be solved by admitting realisting amounts of tectonic overpressure, and (3) significant amounts of overpressure were established only locally and episodically.

  10. Blast traumatic brain injury in the rat using a blast overpressure model.

    PubMed

    Yarnell, Angela M; Shaughness, Michael C; Barry, Erin S; Ahlers, Stephen T; McCarron, Richard M; Grunberg, Neil E

    2013-01-01

    Traumatic brain injury (TBI) is a serious health concern for civilians and military populations, and blast-induced TBI (bTBI) has become an increasing problem for military personnel over the past 10 years. To understand the biological and psychological effects of blast-induced injuries and to examine potential interventions that may help to prevent, attenuate, and treat effects of bTBI, it is valuable to conduct controlled animal experiments. This unit discusses available paradigms to model traumatic brain injury in animals, with an emphasis on the relevance of these various models to study blast-induced traumatic brain injury (bTBI). This paper describes the detailed methods of a blast overpressure (BOP) paradigm that has been used to conduct experiments with rats to model blast exposure. This particular paradigm models the pressure wave created by explosions, including improvised explosive devices (IEDs).

  11. Short-range, overpressure-driven methane migration in coarse-grained gas hydrate reservoirs

    DOE PAGES

    Nole, Michael; Daigle, Hugh; Cook, Ann E.; ...

    2016-08-31

    Two methane migration mechanisms have been proposed for coarse-grained gas hydrate reservoirs: short-range diffusive gas migration and long-range advective fluid transport from depth. Herein we demonstrate that short-range fluid flow due to overpressure in marine sediments is a significant additional methane transport mechanism that allows hydrate to precipitate in large quantities in thick, coarse-grained hydrate reservoirs. Two-dimensional simulations demonstrate that this migration mechanism, short-range advective transport, can supply significant amounts of dissolved gas and is unencumbered by limitations of the other two end-member mechanisms. Here, short-range advective migration can increase the amount of methane delivered to sands as compared tomore » the slow process of diffusion, yet it is not necessarily limited by effective porosity reduction as is typical of updip advection from a deep source.« less

  12. Short-range, overpressure-driven methane migration in coarse-grained gas hydrate reservoirs

    SciTech Connect

    Nole, Michael; Daigle, Hugh; Cook, Ann E.; Malinverno, Alberto

    2016-08-31

    Two methane migration mechanisms have been proposed for coarse-grained gas hydrate reservoirs: short-range diffusive gas migration and long-range advective fluid transport from depth. Herein we demonstrate that short-range fluid flow due to overpressure in marine sediments is a significant additional methane transport mechanism that allows hydrate to precipitate in large quantities in thick, coarse-grained hydrate reservoirs. Two-dimensional simulations demonstrate that this migration mechanism, short-range advective transport, can supply significant amounts of dissolved gas and is unencumbered by limitations of the other two end-member mechanisms. Here, short-range advective migration can increase the amount of methane delivered to sands as compared to the slow process of diffusion, yet it is not necessarily limited by effective porosity reduction as is typical of updip advection from a deep source.

  13. Short-range, overpressure-driven methane migration in coarse-grained gas hydrate reservoirs

    NASA Astrophysics Data System (ADS)

    Nole, Michael; Daigle, Hugh; Cook, Ann E.; Malinverno, Alberto

    2016-09-01

    Two methane migration mechanisms have been proposed for coarse-grained gas hydrate reservoirs: short-range diffusive gas migration and long-range advective fluid transport from depth. Herein, we demonstrate that short-range fluid flow due to overpressure in marine sediments is a significant additional methane transport mechanism that allows hydrate to precipitate in large quantities in thick, coarse-grained hydrate reservoirs. Two-dimensional simulations demonstrate that this migration mechanism, short-range advective transport, can supply significant amounts of dissolved gas and is unencumbered by limitations of the other two end-member mechanisms. Short-range advective migration can increase the amount of methane delivered to sands as compared to the slow process of diffusion, yet it is not necessarily limited by effective porosity reduction as is typical of updip advection from a deep source.

  14. A study of the safety of the ASTM D5304 oxygen overpressure stability test

    SciTech Connect

    White, E.W.; Flohr, K.W.

    1995-04-01

    While the test method for assessing distillate fuel storage stability by oxygen overpressure was being evaluated as a potential ASTM standard, a question of its safety was raised, specifically whether the juxta-position of liquid fuel and oxygen at elevated pressure could lead to explosive self ignition. As a consequence, the authors conducted a literature search followed by a small experimental program. The results of those studies show that the temperature and pressure used in Test Method D5304 are probably safely below the conditions that would lead to autoignition of normal middle distillate fuels. However, middle distillate fuels of unknown or unusual sources, or containing additives, e.g. ignition improvers, should be screened before evaluating their stability by Test Method D5304.

  15. Impact of the AD 79 explosive eruption on Pompeii, I. Relations amongst the depositional mechanisms of the pyroclastic products, the framework of the buildings and the associated destructive events

    NASA Astrophysics Data System (ADS)

    Luongo, Giuseppe; Perrotta, Annamaria; Scarpati, Claudio

    2003-08-01

    A quantitative and qualitative evaluation of the damage caused by the products of explosive eruptions to buildings provides an excellent contribution to the understanding of the various eruptive processes during such dramatic events. To this end, the impact of the products of the two main phases (pumice fallout and pyroclastic density currents) of the Vesuvius AD 79 explosive eruption onto the Pompeii buildings has been evaluated. Based on different sources of data, such as photographs and documents referring to the archaeological excavations of Pompeii, the stratigraphy of the pyroclastic deposits, and in situ inspection of the damage suffered by the buildings, the present study has enabled the reconstruction of the events that occurred inside the city when the eruption was in progress. In particular, we present new data related to the C.J. Polibius' house, a large building located inside Pompeii. From a comparison of all of the above data sets, it has been possible to reconstruct, in considerable detail, the stratigraphy of the pyroclastic deposits accumulated in the city, to understand the direction of collapse of the destroyed walls, and to evaluate the stratigraphic level at which the walls collapsed. Finally, the distribution and style of the damage allow us to discuss how the emplacement mechanisms of the pyroclastic currents are influenced by their interaction with the urban centre. All the data suggest that both structure and shape of the town buildings affected the transport and deposition of the erupted products. For instance, sloping roofs 'drained' a huge amount of fall pumice into the 'impluvia' (a rectangular basin in the centre of the hall with the function to collect the rain water coming from a hole in the centre of the roof), thus producing anomalous deposit thicknesses. On the other hand, flat and low-sloping roofs collapsed under the weight of the pyroclastic material produced during the first phase of the eruption (pumice fall). In addition

  16. Overpressure and hydrocarbon accumulations in Tertiary strata, Gulf Coast of Louisiana

    USGS Publications Warehouse

    Nelson, Philip H.

    2012-01-01

    Many oil and gas reservoirs in Tertiary strata of southern Louisiana are located close to the interface between a sand-rich, normally pressured sequence and an underlying sand-poor, overpressured sequence. This association, recognized for many years by Gulf Coast explorationists, is revisited here because of its relevance to an assessment of undiscovered oil and gas potential in the Gulf Coast of Louisiana. The transition from normally pressured to highly overpressured sediments is documented by converting mud weights to pressure, plotting all pressure data from an individual field as a function of depth, and selecting a top and base of the pressure transition zone. Vertical extents of pressure transition zones in 34 fields across southern onshore Louisiana range from 300 to 9000 ft and are greatest in younger strata and in the larger fields. Display of pressure transition zones on geologic cross sections illustrates the relative independence of the depth of the pressure transition zone and geologic age. Comparison of the depth distribution of pressure transition zones with production intervals confirms previous findings that production intervals generally overlap the pressure transition zone in depth and that the median production depth lies above the base of the pressure transition zone in most fields. However, in 11 of 55 fields with deep drilling, substantial amounts of oil and gas have been produced from depths deeper than 2000 ft below the base of the pressure transition zone. Mud-weight data in 7 fields show that "local" pressure gradients range from 0.91 to 1.26 psi/ft below the base of the pressure transition zone. Pressure gradients are higher and computed effective stress gradients are negative in younger strata in coastal areas, indicating that a greater potential for fluid and sediment movement exists there than in older Tertiary strata.

  17. Blast induced neurotrauma causes overpressure dependent changes to the DNA methylation equilibrium.

    PubMed

    Bailey, Zachary S; Grinter, Michael B; De La Torre Campos, Diego; VandeVord, Pamela J

    2015-09-14

    Traumatic brain injury (TBI) has a high prevalence in our society and often leads to morbidity and mortality. TBI also occurs frequently in a military setting where exposure to blast waves is common. Abnormal gene expression involved with oxidative stress, inflammation and neuronal apoptosis has been well documented following blast induced neurotrauma (BINT). Altered epigenetic transcriptional regulation through DNA methylation has been implicated in the pathology of the injury. Imbalance between DNA methylation and DNA demethylation may lead to altered methylation patterns and subsequent changes in gene transcription. DNA methyltransferase enzymes (DNMT1, DNMT3a, and DNMT3b) are responsible for the addition of methyl groups to DNA, DNA methylation. Whereas the combined function of ten-eleven translocation enzymes (TET1, TET2, and TET3) and thymine-DNA glycosylase (TDG) result in the removal of methyl groups from DNA, DNA demethylation. We used an established rodent model of BINT to assess changes in DNA methylation and demethylation enzymes following injury. Three different blast overpressures were investigated (10, 17 and 23psi). Gene expression was investigated in the prefrontal cortex and hippocampus two weeks following injury. We observed DNMT, TET and TDG expression changes between pressure groups and brain regions. The hippocampus was more vulnerable to enzyme expression changes than the prefrontal cortex, which correlated with aberrant DNA methylation. A significant negative correlation was found between global DNA methylation and the magnitude of blast overpressure exposure. Through transcriptional regulation, altered DNA methylation patterns may offer insight into the characteristic outcomes associated with the injury pathology including inflammation, oxidative stress and apoptosis. As such, these enzymes may be important targets to future therapeutic intervention strategies. Published by Elsevier Ireland Ltd.

  18. Textbook Coverage of the Destruction of the Armenians

    ERIC Educational Resources Information Center

    Lindquist, David H.

    2012-01-01

    Despite its importance as the event establishing that the 20th century would be known as "the age of genocide," the destruction of the Armenians that occurred between the mid-1890s and 1923 is given marginal coverage in contemporary U. S. high school history textbooks. This article critiques that coverage and identifies the overall flow…

  19. The role of overpressure and seismic activity for the generation of the Tampen Slide, North Sea Trough Mouth Fan

    NASA Astrophysics Data System (ADS)

    Bellwald, Benjamin; Urlaub, Morelia; Oline Hjelstuen, Berit; Petter Sejrup, Hans; Sørensen, Mathilde; Forsberg, Carl Fredrik; Vanneste, Maarten

    2017-04-01

    Trough mouth fans (TMFs) are environments characterized by high sediment supply during glacial stages and repeated slope failure. The Tampen Slide, which removed 1800 km3 of sediment at 130 ka BP, is one of several paleo-slides at the North Sea TMF deposited at the outlet of the Norwegian Channel, SE Nordic Sea margin. Here we use 2D Finite Element Modeling to evaluate the effects of variations in sedimentation rates and sediment properties on overpressure generation and slope stability of this TMF system. The model domain, 40 km in length and 2 km in height, is dominated by deposits of glacigenic debris flows and glacimarine processes. We use geotechnical values measured on samples of glacial debris and (glaci)marine deposits from over the Ormen Lange gas field area. Slope stability has been modeled for constant temporal sediment loading, episodic changes in sedimentation rates and abrupt pulses in sediment delivery for the 61 ka of marine isotope stage 6. The models show that increased sedimentation rates during glacial stages generate insufficient overpressure to trigger the Tampen Slide. Furthermore, the simulated overpressures do not significantly differ at the end of the model runs characterized by different sedimentation patterns. The results also highlight the importance of a basal glacimarine layer underneath the rapidly-deposited sediments for the build-up of overpressure. Consequently, this glacimarine layer has the inherited potential to act as a weak layer facilitating instability. However, as overpressure due to sediment deposition alone does not result in slope failure, we couple the preconditioned slope with earthquake ground shaking. Based on attenuation models, an earthquake of M6.9 or larger at a short distance from the Tampen Slide headwall could have triggered the Tampen Slide. Therefore we suggest glacial sedimentation and a glacimarine layer to represent preconditioning factors, and seismic shaking as the controlling factor for the Tampen

  20. Nonlinear coherent destruction of tunneling

    SciTech Connect

    Luo Xiaobing; Xie Qiongtao; Wu Biao

    2007-11-15

    We study theoretically two coupled periodically curved optical waveguides with Kerr nonlinearity. We find that the tunneling between the waveguides can be suppressed in a wide range of parameters. This suppression of tunneling is found to be related to the coherent destruction of tunneling in a linear medium, which in contrast occurs only at isolated parameter points. Therefore, we call this suppression nonlinear coherent destruction of tunneling. This localization phenomenon can be observed readily with current experimental capability; it may also be observable in a different physical system, the Bose-Einstein condensate.

  1. Polymer mechanochemistry: from destructive to productive.

    PubMed

    Li, Jun; Nagamani, Chikkannagari; Moore, Jeffrey S

    2015-08-18

    When one brings "polymeric materials" and "mechanical action" into the same conversation, the topic of this discussion might naturally focus on everyday circumstances such as failure of fibers, fatigue of composites, abrasion of coatings, etc. This intuitive viewpoint reflects the historic consensus in both academia and industry that mechanically induced chemical changes are destructive, leading to polymer degradation that limits materials lifetime on both macroscopic and molecular levels. In the 1930s, Staudinger observed mechanical degradation of polymers, and Melville later discovered that polymer chain scission caused the degradation. Inspired by these historical observations, we sought to redirect the destructive mechanical energy to a productive form that enables mechanoresponsive functions. In this Account, we provide a personal perspective on the origin, barriers, developments, and key advancements of polymer mechanochemistry. We revisit the seminal events that offered molecular-level insights into the mechanochemical behavior of polymers and influenced our thinking. We also highlight the milestones achieved by our group along with the contributions from key comrades at the frontier of this field. We present a workflow for the design, evaluation, and development of new "mechanophores", a term that has come to mean a molecular unit that chemically responds in a selective manner to a mechanical perturbation. We discuss the significance of computation in identifying pairs of points on the mechanophore that promote stretch-induced activation. Attaching polymer chains to the mechanophore at the most sensitive pair and locating the mechanophore near the center of a linear polymer are thought to maximize the efficiency of mechanical-to-chemical energy transduction. We also emphasize the importance of control experiments to validate mechanochemical transformations, both in solution and in the solid state, to differentiate "mechanical" from "thermal" activation

  2. Atlantis Non-destructive Testing

    NASA Image and Video Library

    2003-10-29

    In the Orbiter Processing Facility, the nose cap (foreground) removed from Atlantis (behind) waits to be shipped to the original manufacturing company, Vought in Ft. Worth, Texas, a subsidiary of Lockheed Martin, to undergo non-destructive testing such as CAT scan and thermography.

  3. THE SITE OF ANGIOTONIN DESTRUCTION

    PubMed Central

    Sapirstein, Leo A.; Reed, Racheal K.; Page, Ernest W.

    1946-01-01

    1. Theoretical considerations render it unlikely that the greatest part of the angiotonase found in the organism is available for the destruction of angiotonia. A priori considerations support the view that only plasma angiotonase is involved in angiotonin destruction in vivo. 2. We have utilized the magnitude and duration of the presser response to angiotonin as an index of available angiotonase, and we have found that: (a) Nephrectomy and evisceration are without marked effect on angiotonin response. (b) Hemorrhage and hemodilution without shock cause a striking increase in the response to angiotonin and this appears to be due to removal of the plasma rather than the cells. Shock developing after hemorrhage results in a state of refractoriness to angiotonin. (c) Intact red cells in vitro have no destructive action on angiotonin, but after hemolysis they have several hundred times the activity of plasma, (d) Intravascular hemolysis, whether produced in vitro or in vivo, decreases the response to angiotonin to a degree which is consistent with the hypothesis that the normal animal destroys angiotonin entirely in its plasma. The active principle in hemolyzed blood is destroyed by heating to 65–70°C. for 15 minutes. 3. These findings support the hypothesis that all or at least the greatest part of angiotonin destruction under physiological circumstances occurs in the plasma, and the significance of this hypothesis is discussed. PMID:19871540

  4. Destructive wrist arthropathy of pseudogout

    SciTech Connect

    Smathers, R.L.; Keats, T.E.; Stelling, C.B.

    1982-01-01

    The wrist is a frequent site of arthropathy in the pseudogout syndrome (calcium pyrophosphate dihydrate crystal deposition disease). Three cases of severe wrist arthropathy are presented to emphasize the destructive changes which may occur, including necrosis or collapse of the lunate and navicular bones. The roentgenographic findings characteristic of pseudogout in the wrist are discussed.

  5. Conceptualizing Chronic Self-Destructiveness.

    ERIC Educational Resources Information Center

    Kelley, Kathryn

    Self-destructiveness can be viewed in two ways: as performing an act which one knows cognitively is not conducive to one's welfare but nonetheless leads to some pleasurable affect (e.g., overeating, smoking); or not performing an act one knows one should perform but which has some negative affective consequences (e.g., dental checkups, saving…

  6. Switches in the Stress Field Induced by Fluid Overpressures Below a Low-Permeability Fault Zone

    NASA Astrophysics Data System (ADS)

    Collettini, C.; de Paola, N.; Goulty, N. R.

    2005-12-01

    The geological structure of Elba comprises thrust sheets stacked during the Apennine orogeny that are cross-cut by later Neogene extensional faults. The Zuccale fault is a gently east-dipping normal fault that offsets part of the thrust stack eastwards. Stratigraphic separations imply an offset of 7-8 km and exhumation of 3-6 km. A complex hydrofracture system exposed in the footwall of Palaeozoic schists and Triassic sediments at Punta di Zuccale consists of three vein sets: two vertical sets trending N-S and E-W and one sub-horizontal. The veins show a crack-and-seal texture and are characterized by mutual crosscutting relationships. The regional stress field throughout the period when the Zuccale fault was active, evidenced by numerous kinematic indicators, was extensional with the minimum principal stress oriented E-W, consistent with the N-S trending set of vertical hydrofractures. We interpret the vertical E-W trending and sub-horizontal hydrofractures as the result of overpressure development, due to exhumation, below the low-permeability, phyllosilicate-rich fault core. In our proposed mechanical model, exhumation reduced the vertical stress and also the horizontal stresses which responded poroelastically. The N-S trending vertical hydrofractures formed when the pore pressure exceeded the minimum principal stress by the tensile strength of the rock. Continued exhumation further reduced the vertical and N-S principal stresses, whilst the E-W principal stress remained equal to the pore pressure, until the pore pressure exceeded the N-S principal stress by the tensile strength of the rock, causing the E-W hydrofractures to form. Yet more exhumation further reduced the vertical stress, while the horizontal stresses remained equal to the pore pressure, until the pore pressure exceeded the vertical stress by the tensile strength of the rock, causing the sub-horizontal hydrofractures to form. The reduced normal effective stress across the fault encouraged fault

  7. Prevention of Over-Pressurization During Combustion in a Sealed Chamber

    NASA Technical Reports Server (NTRS)

    Gokoglu, Suleyman A.; Niehaus, Justin E.; Olson, Sandra L.; Dietrich, Daniel L.; Ruff, Gary A.; Johnston, Michael C.

    2012-01-01

    The combustion of flammable material in a sealed chamber invariably leads to an initial pressure rise in the volume. The pressure rise is due to the increase in the total number of gaseous moles (condensed fuel plus chamber oxygen combining to form gaseous carbon dioxide and water vapor) and, most importantly, the temperature rise of the gas in the chamber. Though the rise in temperature and pressure would reduce with time after flame extinguishment due to the absorption of heat by the walls and contents of the sealed spacecraft, the initial pressure rise from a fire, if large enough, could lead to a vehicle over-pressure and the release of gas through the pressure relief valve. This paper presents a simple lumped-parameter model of the pressure rise in a sealed chamber resulting from the heat release during combustion. The transient model considers the increase in gaseous moles due to combustion, and heat transfer to the chamber walls by convection and radiation and to the fuel-sample holder by conduction, as a function of the burning rate of the material. The results of the model are compared to the pressure rise in an experimental chamber during flame spread tests as well as to the pressure falloff after flame extinguishment. The experiments involve flame spread over thin solid fuel samples. Estimates of the heat release rate profiles for input to the model come from the assumed stoichiometric burning of the fuel along with the observed flame spread behavior. The sensitivity of the model to predict maximum chamber pressure is determined with respect to the uncertainties in input parameters. Model predictions are also presented for the pressure profile anticipated in the Fire Safety-1 experiment, a material flammability and fire safety experiment proposed for the European Space Agency (ESA) Automated Transfer Vehicle (ATV). Computations are done for a range of scenarios including various initial pressures and sample sizes. Based on these results, various

  8. Design and fabrication of a 30 T superconducting solenoid using overpressure processed Bi2212 round wire

    SciTech Connect

    Flanagan, Gene; Johnson, Rolland

    2016-02-18

    High field superconducting magnets are used in particle colliders, fusion energy devices, and spectrometers for medical imaging and advanced materials research. Magnets capable of generating fields of 20-30 T are needed by future accelerator facilities. A 20-30 T magnet will require the use of high-temperature superconductors (HTS) and therefore the challenges of high field HTS magnet development need to be addressed. Superconducting Bi2Sr2CaCu2Ox (Bi2212) conductors fabricated by the oxide-powder-in-tube (OPIT) technique have demonstrated the capability to carry large critical current density of 105 A/cm2 at 4.2 K and in magnetic fields up to 45 T. Available in round wire multi-filamentary form, Bi2212 may allow fabrication of 20-50 T superconducting magnets. Until recently the performance of Bi2212 has been limited by challenges in realizing high current densities (Jc ) in long lengths. This problem now is solved by the National High Magnetic Field Lab using an overpressure (OP) processing technique, which uses external pressure to process the conductor. OP processing also helps remove the ceramic leakage that results when Bi-2212 liquid leaks out from the sheath material and reacts with insulation, coil forms, and flanges. Significant advances have also been achieved in developing novel insulation materials (TiO2 coating) and Ag-Al sheath materials that have higher mechanical strengths than Ag-0.2wt.% Mg, developing heat treatment approaches to broadening the maximum process temperature window, and developing high-strength, mechanical reinforced Bi-2212 cables. In the Phase I work, we leveraged these new opportunities to prototype overpressure processed solenoids and test them in background fields of up to 14 T. Additionally a design of a fully superconducting 30 T solenoid was produced. This work in conjunction with the future path outlined in the Phase II proposal would

  9. Attenuation of pulmonary inflammation after exposure to blast overpressure by N-acetylcysteine amide.

    PubMed

    Chavko, Mikulas; Adeeb, Saleena; Ahlers, Stephen T; McCarron, Richard M

    2009-09-01

    Lung contusion is a common problem from blunt chest trauma caused by mechanical forces and by exposure to blast overpressure, often with fatal consequences. Lung contusion is also a risk factor for the development of pneumonia, severe clinical acute lung injury (ALI), and acute respiratory distress syndrome (ARDS). Infiltrating neutrophils are considered to be central mediators of lung injuries after blunt trauma. Recent studies have demonstrated that antioxidants reduced pulmonary inflammation in different models of lung damage. This study examined the effect of antioxidant N-acetylcysteine amide (NACA) on the progression of lung inflammation after exposure to a moderate level of blast overpressure (140 kPa). Rats were administered with NACA (i.p. 100 mg/kg) or placebo (PBS) 30, 60 min and 24 h after exposure. Nonblasted sham-injected animals served as controls. Neutrophil infiltration measured by myeloperoxidase (MPO) activity in the lung was significantly increased at 2 days after blast and returned to controls at 8 days. This increase corresponded with activation of integrin CD11b mRNA and lung inflammatory chemokine mRNA expression; macrophage inflammatory protein-1 (MIP-1), monocyte chemotactic peptide-1 (MCP-1), and cytokine-induced neutrophil chemoattractant-1 (CINC-1). At 8 days, all inflammatory mediators returned to control levels. In addition, expression of heme oxygenase-1 (HO-1) mRNA increased at 2 days after exposure. No changes were detected in the lung manganase superoxide dismutase (MnSOD) or glutathione reductase (GR) mRNA expression after blast. N-Acetylcysteine amide significantly reduced infiltration of neutrophils and CD11b mRNA activation in lungs, and completely blocked activation of MIP-1, MCP-1 and CINC-1 mRNA. The relatively higher inhibition of chemokine mRNAs compared with reduction in MPO activity and CD11b is in accordance with an antioxidant effect of NACA on reactive oxygen species (ROS) accumulation, rather than by an effect on

  10. The significance of vortex ring formation and nozzle exit over-pressure to pulsatile jet propulsion

    NASA Astrophysics Data System (ADS)

    Krueger, Paul Samuel

    Pulsatile jet propulsion can be accomplished using a fully-pulsed jet (i.e., a periodic series of starting jets or pulses), the unsteady nature of which engenders vortex ring formation. The propulsive significance of vortex ring formation in this setting is studied experimentally using a piston-cylinder mechanism to generate starting and fully-pulsed, round jets of water into water. Starting jets are considered separately since they are the limiting case of a fully-pulsed jet at zero pulsing frequency. Measurements of the total impulse per pulse (starting jets) and time-averaged thrust (fully-pulsed jets) are made using a force balance. Digital particle image velocimetry (DPIV) measurements provide information about the resulting jet flow. Piston stroke to diameter ratios (L/D) between 2 and 8 are used to generate the pulses for both types of jets. This range brackets the transition between pulses that generate isolated vortex rings (small L/D) and pulses that yield a leading vortex ring that has pinched off from the generating jet, producing a trailing jet (large L/D). Impulse measurements for the starting jets as a function of L/D indicate the leading vortex ring adds proportionately more impulse per pulse than a trailing jet. This leads to a maximum in the average thrust during a pulse at an L/D just before vortex ring pinch off is observed. The propulsive advantage of vortex ring formation over trailing-jet ejection is due to nozzle exit over-pressure. This over-pressure can be related to the acceleration of ambient fluid in the form of added and entrained mass during ring formation. A simple model is proposed to describe these effects at the initiation of an impulsive pulse. The thrust measurements for fully-pulsed jets show a propulsive benefit from vortex ring formation (i.e., non-dimensional thrust, FIJ , > 1) for all non-dimensional pulsing frequencies, StL, accessible by a fully-pulsed jet. As with starting jets (StL = 0), vortex ring pinch off reduces

  11. Modelling shear bands in a volcanic conduit: Implications for over-pressures and extrusion-rates

    NASA Astrophysics Data System (ADS)

    Hale, Alina J.; Mühlhaus, Hans-B.

    2007-11-01

    Shear bands in a volcanic conduit are modelled for crystal-rich magma flow using simplified conditions to capture the fundamental behaviour of a natural system. Our simulations begin with magma crystallinity in equilibrium with an applied pressure field and isothermal conditions. The viscosity of the magma is derived using existing empirical equations and is dependent upon temperature, water content and crystallinity. From these initial conduit conditions we utilize the Finite Element Method, using axi-symmetric coordinates, to simulate shear bands via shear localisation. We use the von Mises visco-plasticity model with constant magma shear strength for a first look into the effects of plasticity. The extent of shear bands in the conduit is explored with a numerical model parameterized with values appropriate for Soufrière Hills Volcano, Montserrat, although the model is generic in nature. Our model simulates shallow (up to approximately 700 m) shear bands that occur within the upper conduit and probably govern the lava extrusion style due to shear boundaries. We also model the change in the over-pressure field within the conduit for flow with and without shear bands. The pressure change can be as large as several MPa at shallow depths in the conduit, which generates a maximum change in the pressure gradient of 10's of kPa/m. The formation of shear bands could therefore provide an alternative or additional mechanism for the inflation/deflation of the volcano flanks as measured by tilt-metres. Shear bands are found to have a significant effect upon the magma ascent rate due to shear-induced flow reducing conduit friction and altering the over-pressure in the upper conduit. Since we do not model frictional controlled slip, only plastic flow, our model calculates the minimum change in extrusion rate due to shear bands. However, extrusion rates can almost double due to the formation of shear bands, which may help suppress volatile loss. Due to the paucity of data and

  12. Developmentally programmed nuclear destruction during yeast gametogenesis.

    PubMed

    Eastwood, Michael D; Cheung, Sally W T; Lee, Kwan Yin; Moffat, Jason; Meneghini, Marc D

    2012-07-17

    Autophagy controls cellular catabolism in diverse eukaryotes and modulates programmed cell death in plants and animals. While studies of the unicellular yeast Saccharomyces cerevisiae have provided fundamental insights into the mechanisms of autophagy, the roles of cell death pathways in yeast are less well understood. Here, we describe widespread developmentally programmed nuclear destruction (PND) events that occur during yeast gametogenesis. PND is executed through apoptotic-like DNA fragmentation in coordination with an unusual form of autophagy that is most similar to mammalian lysosomal membrane permeabilization and mega-autophagy, a form of plant autophagic cell death. Undomesticated strains execute gametogenic PND broadly in maturing colonies to the apparent benefit of sibling cells, confirming its prominence during the yeast life cycle. Our results reveal that diverse cell-death-related processes converge during gametogenesis in a microbe distantly related to plants or animals, highlighting gametogenesis as a process during which programmed cell death mechanisms may have evolved.

  13. Community Destruction and Traumatic Stress in Post-Tsunami Indonesia

    PubMed Central

    Frankenberg, Elizabeth; Nobles, Jenna; Sumantri, Cecep

    2013-01-01

    How are individuals affected when the communities they live in change for the worse? This question is central to understanding neighborhood effects, but few study designs generate estimates that can be interpreted causally. We address issues of inference through a natural experiment, examining post-traumatic stress at multiple time points in a population differentially exposed to the 2004 Indian Ocean tsunami. The data, from the Study of the Tsunami Aftermath and Recovery, include interviews with over 16,000 Indonesian adults before and after the event. These data are combined with satellite imagery, direct observation, and informant interviews to examine the consequences of community destruction for post-traumatic stress. Using multilevel linear mixed models, we show that community destruction worsens post-traumatic stress, net of rigorous controls for individual experiences of trauma and loss. Furthermore, the effect of community destruction persists over time and extends across a wide range of community types. PMID:22940603

  14. Community destruction and traumatic stress in post-tsunami Indonesia.

    PubMed

    Frankenberg, Elizabeth; Nobles, Jenna; Sumantri, Cecep

    2012-01-01

    How are individuals affected when the communities they live in change for the worse? This question is central to understanding neighborhood effects, but few study designs generate estimates that can be interpreted causally. We address issues of inference through a natural experiment, examining post-traumatic stress at multiple time points in a population differentially exposed to the 2004 Indian Ocean tsunami. The data, from the Study of the Tsunami Aftermath and Recovery, include interviews with over 16,000 Indonesian adults before and after the event. These data are combined with satellite imagery, direct observation, and informant interviews to examine the consequences of community destruction for post-traumatic stress. Using multilevel linear mixed models, we show that community destruction worsens post-traumatic stress, net of rigorous controls for individual experiences of trauma and loss. Furthermore, the effect of community destruction persists over time and extends across a wide range of community types.

  15. Destruction of a Magnetized Star

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2017-01-01

    completely.Amplifying EncountersFor stars that survive their encounter with the black hole, Guillochon and McCourt find that the process of partial disruption and re-accretion can amplify the magnetic field of the star by up to a factor of 20. Repeated encounters of the star with the black hole could amplify the field even more.The authors suggest an interesting implication of this idea: a population of highly magnetized stars may have formed in our own galactic center, resulting from their encounters with the supermassive black hole Sgr A*.A turbulent magnetic field forms after a partial stellar disruption and re-accretion of the tidal tails. [Adapted from Guillochon McCourt 2017]Effects in DestructionFor stars that are completely shredded and form a tidal stream after their encounter with the black hole, the authors find that the magnetic field geometry straightens within the stream of debris. There, the pressure of the magnetic field eventually dominates over the gas pressure and self-gravity.Guillochon and McCourt find that the fields new configuration isnt ideal for powering jets from the black hole but it is strong enough to influence how the stream interacts with itself and its surrounding environment, likely affecting what we can expect to see from these short-lived events.These simulations have clearly demonstrated the need to further explore the role of magnetic fields in the disruptions of stars by black holes.BonusCheck out the full (brief) video from one of the simulations by Guillochon and McCourt (be sure to watch it in high-res!). It reveals the evolution of a stars magnetic field configuration as the star is partially disrupted by the forces of a supermassive black hole and then re-accretes.CitationJames Guillochon and Michael McCourt 2017 ApJL 834 L19. doi:10.3847/2041-8213/834/2/L19

  16. New-construction techniques and HVAC (heating, venting and air conditioning) overpressurization for radon reduction in schools

    SciTech Connect

    Witter, K.A.; Craig, A.B.; Saum, D.

    1988-04-01

    Construction of a school in Fairfax County, Virginia, is being carefully monitored since elevated indoor radon levels have been identified in many existing houses near the site. Soil-gas radon concentrations measured prior to pouring of the slabs were also indicative of a potential radon problem should the soil gas enter the school; however, subslab radon measurements collected thus far are lower than anticipated. In addition, the school's heating, ventilating, and air-conditioning (HVAC) system has been designed to operate continously in overpressurization to help reduce pressure-driven entry of radon-containing soil gas into the building. Following completion, indoor radon levels in the school will be monitored to determine the effectiveness of these radon-resistant new-construction techniques and HVAC overpressurization in limiting radon entry into the school.

  17. Chondrule Destruction in Nebular Shocks

    NASA Astrophysics Data System (ADS)

    Jacquet, Emmanuel; Thompson, Christopher

    2014-12-01

    Chondrules are millimeter-sized silicate spherules ubiquitous in primitive meteorites, but whose origin remains mysterious. One of the main proposed mechanisms for producing them is melting of solids in shock waves in the gaseous protoplanetary disk. However, evidence is mounting that chondrule-forming regions were enriched in solids well above solar abundances. Given the high velocities involved in shock models, destructive collisions would be expected between differently sized grains after passage of the shock front as a result of differential drag. We investigate the probability and outcome of collisions of particles behind a one-dimensional shock using analytic methods as well as a full integration of the coupled mass, momentum, energy, and radiation equations. Destruction of protochondrules seems unavoidable for solid/gas ratios epsilon >~ 0.1, and possibly even for solar abundances because of "sandblasting" by finer dust. A flow with epsilon >~ 10 requires much smaller shock velocities (~2 versus 8 km s-1) in order to achieve chondrule-melting temperatures, and radiation trapping allows slow cooling of the shocked fragments. Initial destruction would still be extensive; although re-assembly of millimeter-sized particles would naturally occur by grain sticking afterward, the compositional heterogeneity of chondrules may be difficult to reproduce. We finally note that solids passing through small-scale bow shocks around few kilometer-sized planetesimals might experience partial melting and yet escape fragmentation.

  18. Chondrule destruction in nebular shocks

    SciTech Connect

    Jacquet, Emmanuel; Thompson, Christopher

    2014-12-10

    Chondrules are millimeter-sized silicate spherules ubiquitous in primitive meteorites, but whose origin remains mysterious. One of the main proposed mechanisms for producing them is melting of solids in shock waves in the gaseous protoplanetary disk. However, evidence is mounting that chondrule-forming regions were enriched in solids well above solar abundances. Given the high velocities involved in shock models, destructive collisions would be expected between differently sized grains after passage of the shock front as a result of differential drag. We investigate the probability and outcome of collisions of particles behind a one-dimensional shock using analytic methods as well as a full integration of the coupled mass, momentum, energy, and radiation equations. Destruction of protochondrules seems unavoidable for solid/gas ratios ε ≳ 0.1, and possibly even for solar abundances because of 'sandblasting' by finer dust. A flow with ε ≳ 10 requires much smaller shock velocities (∼2 versus 8 km s{sup –1}) in order to achieve chondrule-melting temperatures, and radiation trapping allows slow cooling of the shocked fragments. Initial destruction would still be extensive; although re-assembly of millimeter-sized particles would naturally occur by grain sticking afterward, the compositional heterogeneity of chondrules may be difficult to reproduce. We finally note that solids passing through small-scale bow shocks around few kilometer-sized planetesimals might experience partial melting and yet escape fragmentation.

  19. Overpressure generation by load transfer following shale framework weakening due to smectite diagenesis

    USGS Publications Warehouse

    Lahann, R.W.; Swarbrick, R.E.

    2011-01-01

    Basin model studies which have addressed the importance of smectite conversion to illite as a source of overpressure in the Gulf of Mexico have principally relied on a single-shale compaction model and treated the smectite reaction as only a fluid-source term. Recent fluid pressure interpretation and shale petrology studies indicate that conversion of bound water to mobile water, dissolution of load-bearing grains, and increased preferred orientation change the compaction properties of the shale. This results in substantial changes in effective stress and fluid pressure. The resulting fluid pressure can be 1500-3000psi higher than pressures interpreted from models based on shallow compaction trends. Shale diagenesis changes the mineralogy, volume, and orientation of the load-bearing grains in the shale as well as the volume of bound water. This process creates a weaker (more compactable) grain framework. When these changes occur without fluid export from the shale, some of the stress is transferred from the grains onto the fluid. Observed relationships between shale density and calculated effective stress in Gulf of Mexico shelf wells confirm these changes in shale properties with depth. Further, the density-effective stress changes cannot be explained by fluid-expansion or fluid-source processes or by prediagenesis compaction, but are consistent with a dynamic diagenetic modification of the shale mineralogy, texture, and compaction properties during burial. These findings support the incorporation of diagenetic modification of compaction properties as part of the fluid pressure interpretation process. ?? 2011 Blackwell Publishing Ltd.

  20. Delineating Area of Review in a System with Pre-injection Relative Overpressure

    SciTech Connect

    Oldenburg, Curtis M.; Cihan, Abdullah; Zhou, Quanlin; Fairweather, Stacey; Spangler, Lee H.

    2014-12-31

    The Class VI permit application for geologic carbon sequestration (GCS) requires delineation of an area of review (AoR), defined as the region surrounding the (GCS) project where underground sources of drinking water (USDWs) may be endangered. The methods for estimating AoR under the Class VI regulation were developed assuming that GCS reservoirs would be in hydrostatic equilibrium with overlying aquifers. Here we develop and apply an approach to estimating AoR for sites with preinjection relative overpressure for which standard AoR estimation methods produces an infinite AoR. The approach we take is to compare brine leakage through a hypothetical open flow path in the base-case scenario (no-injection) to the incrementally larger leakage that would occur in the CO2-injection case. To estimate AoR by this method, we used semi-analytical solutions to single-phase flow equations to model reservoir pressurization and flow up (single) leaky wells located at progressively greater distances from the injection well. We found that the incrementally larger flow rates for hypothetical leaky wells located 6 km and 4 km from the injection well are ~20% and 30% greater, respectively, than hypothetical baseline leakage rates. If total brine leakage is considered, the results depend strongly on how the incremental increase in total leakage is calculated, varying from a few percent to up to 40% greater (at most at early time) than base-case total leakage.

  1. Experiments on Dynamic Overpressure Stabilization of Ablative Richtmyer--Meshkov Growth in ICF Targets on OMEGA

    NASA Astrophysics Data System (ADS)

    Gotchev, O. V.; Goncharov, V. N.; Jaanimagi, P. A.; Knauer, J. P.; Meyerhofer, D. D.

    2002-11-01

    Dynamic overpressure sets the growth rate of the ablative Richtmyer--Meshkov (RM) instability and the late-time imprint levels in directly driven ICF targets. It leads to temporal oscillations of the perturbed ablation front, which have been predicted analytically and observed experimentally,(Y. Aglitskiy et al.), Phys. Plasmas 9, 2264 (2002). and in 2-D ORCHID simulations. These predictions were verified on OMEGA by measuring the perturbation amplitudes and frequencies directly with an x-ray framing camera through face-on x-ray radiography. Planar plastic targets with variable thickness (20 to 60 μm) and single-mode (λ = 10 to 30 μm) ripples on the front surface were irradiated with 1.5-ns square UV laser pulses at maximum energy. Results clearly indicate a phase reversal in the evolution of the target areal density perturbations, in good agreement with theory and simulation. Nonlinearity in the evolution of the preimposed mode, resulting in an enriched spectrum, was observed for initial amplitudes previously believed to develop linearly with time. Upcoming experiments with a high-resolution, streaked imager, will allow for the detailed recording of the evolution of the RM instability and the competing stabilization effect. This work was supported by the U.S. DOE Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC03-92SF19460.

  2. Results of Overpressurization Test of a 1:4-Scale Prestressed Concrete Containment Vessel Model

    SciTech Connect

    Hessheimer, Michael F.; Shibata, Satoru; Costello, James F.

    2002-07-01

    The Nuclear Power Engineering Corporation (NUPEC) of Japan and the U.S. Nuclear Regulatory Commission (NRC) have been co-sponsoring and jointly funding a Cooperative Containment Research Program at Sandia National Laboratories. The purpose of the program is to investigate the response of representative models of nuclear containment structures to pressure loading beyond the design basis accident and to compare analytical predictions with measured behavior. This is accomplished by conducting static, pneumatic overpressurization tests of scale models at ambient temperature. The first project in this program was a test of a mixed scale steel containment vessel (SCV). Next, a 1:4-scale model of a prestressed concrete containment vessel (PCCV), representative of a pressurized water reactor (PWR) plant in Japan, was constructed by NUPEC at Sandia National Laboratories from January 1997 through June, 2000. Concurrently, Sandia instrumented the model with over 1500 transducers to measure strain, displacement and forces in the model from prestressing through the pressure testing. The limit state test of the PCCV model was conducted in September, 2000 at Sandia National Laboratories. This paper describes the conduct and some of the results of this test. (authors)

  3. Petroleum and aqueous inclusions from deeply buried reservoirs: Experimental simulations and consequences for overpressure estimates

    NASA Astrophysics Data System (ADS)

    Pironon, Jacques; Bourdet, Julien

    2008-10-01

    Synthetic hydrocarbon and aqueous inclusions have been created in the laboratory batch reactors in order to mimic inclusion formation or re-equilibration in deeply buried reservoirs. Inclusions were synthesized in quartz and calcite using pure water and Mexican dead oil, or n-tetradecane (C 14H 30), at a temperature and pressure of 150 °C and 1 kbar. One-phase hydrocarbon inclusions are frequently observed at standard laboratory conditions leading to homogenization temperatures between 0 and 60 °C. UV epifluorescence of Mexican oil inclusions is not uniform; blue and green-yellow colored inclusions coexist; however, no clear evidence of variations in fluid chemistry were observed. Homogenization temperatures were recorded and the maxima of Th plotted on histograms are in good agreement with expected Th in a range of 6 °C. Broad histograms were reconstructed showing non-symmetrical Th distributions over a 20 °C temperature range centered on the expected Th. This histogram broadening is due to the fragility of the fluid inclusions that were created by re-filling of pre-existing microcavities. Such Th histograms are similar to Th histograms recorded on natural samples from deeply buried carbonate reservoirs. Th values lower than those expected were measured for hydrocarbon inclusions in quartz and calcite, and for aqueous inclusions in calcite. However, the results confirm the ability of fluid inclusions containing two immiscible fluids to lead to PT reconstructions, even in overpressured environments.

  4. Impact of reduced near-field entrainment of overpressured volcanic jets on plume development

    USGS Publications Warehouse

    Saffaraval, Farhad; Solovitz, Stephen A.; Ogden, Darcy E.; Mastin, Larry G.

    2012-01-01

    Volcanic plumes are often studied using one-dimensional analytical models, which use an empirical entrainment ratio to close the equations. Although this ratio is typically treated as constant, its value near the vent is significantly reduced due to flow development and overpressured conditions. To improve the accuracy of these models, a series of experiments was performed using particle image velocimetry, a high-accuracy, full-field velocity measurement technique. Experiments considered a high-speed jet with Reynolds numbers up to 467,000 and exit pressures up to 2.93 times atmospheric. Exit gas densities were also varied from 0.18 to 1.4 times that of air. The measured velocity was integrated to determine entrainment directly. For jets with exit pressures near atmospheric, entrainment was approximately 30% less than the fully developed level at 20 diameters from the exit. At pressures nearly three times that of the atmosphere, entrainment was 60% less. These results were introduced into Plumeria, a one-dimensional plume model, to examine the impact of reduced entrainment. The maximum column height was only slightly modified, but the critical radius for collapse was significantly reduced, decreasing by nearly a factor of two at moderate eruptive pressures.

  5. Blast overpressure induced axonal injury changes in rat brainstem and spinal cord.

    PubMed

    Kallakuri, Srinivasu; Purkait, Heena S; Dalavayi, Satya; VandeVord, Pamela; Cavanaugh, John M

    2015-01-01

    Blast induced neurotrauma has been the signature wound in returning soldiers from the ongoing wars in Iraq and Afghanistan. Of importance is understanding the pathomechansim(s) of blast overpressure (OP) induced axonal injury. Although several recent animal models of blast injury indicate the neuronal and axonal injury in various brain regions, animal studies related to axonal injury in the white matter (WM) tracts of cervical spinal cord are limited. The purpose of this study was to assess the extent of axonal injury in WM tracts of cervical spinal cord in male Sprague Dawley rats subjected to a single insult of blast OP. Sagittal brainstem sections and horizontal cervical spinal cord sections from blast and sham animals were stained by neurofilament light (NF-L) chain and beta amyloid precursor protein immunocytochemistry and observed for axonal injury changes. Observations from this preliminary study demonstrate axonal injury changes in the form of prominent swellings, retraction bulbs, and putative signs of membrane disruptions in the brainstem and cervical spinal cord WM tracts of rats subjected to blast OP. Prominent axonal injury changes following the blast OP exposure in brainstem and cervical spinal WM tracts underscores the need for careful evaluation of blast induced injury changes and associated symptoms. NF-L immunocytochemistry can be considered as an additional tool to assess the blast OP induced axonal injury.

  6. The effect of blast overpressure on the mechanical properties of a chinchilla tympanic membrane.

    PubMed

    Liang, Junfeng; Yokell, Zachery A; Nakmaili, Don U; Gan, Rong Z; Lu, Hongbing

    2017-08-18

    The rupture of tympanic membrane (TM) has long been viewed as an indicator of blast injury, especially for hearing loss. However, little is known about damage to the TM caused by blast with pressure lower than the rupture threshold. In this paper, we present our study on the effect of blast overpressure on the static mechanical properties of TM. Chinchilla was used as the animal model and exposed to multiple blasts with pressures lower than the rupture threshold of the TM. Using a micro-fringe projection method, we observed the alteration of the static mechanical properties of post-blast chinchilla's TMs as compared to those of control TMs. Specifically, after exposing to multiple blasts, the Young's modulus of chinchilla TM decreased by ∼53% while the ultimate failure pressure decreased by ∼33%. Scanning Electron Microscope (SEM) images show the damage formation in the post-blast TM as compared with its control counterpart. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Effects of filament size on critical current density in overpressure processed Bi-2212 round wire.

    PubMed

    Jiang, Jianyi; Francis, Ashleigh; Alicea, Ryan; Matras, Maxime; Kametani, Fumitake; Trociewitz, Ulf P; Hellstrom, Eric E; Larbalestier, David C

    2017-06-01

    Bi2Sr2CaCu2Ox (Bi-2212) conductor is the only high temperature superconductor manufactured as a round wire and is a very promising conductor for very high field applications. One of the key design parameters of Bi-2212 wire is its filament size, which has been previously reported to affect the critical current density (Jc ) and ac losses. Work with 1 bar heat treatment showed that the optimal filament diameter was about 15 μm but it was not well understood at that time that gas bubbles were the main current limiting mechanism. Here we investigated a recent Bi-2212 wire with a 121×18 filament architecture with varying wire diameter (1.0 to 1.5 mm) using 50 bar overpressure processing. This wire is part of a 1.2 km piece length of 1.0 mm diameter made by Oxford Superconducting Technology. We found that Jc is independent of the filament size in the range from 9 to 14 μm, although the n value increased with increasing filament size. A new record Jc (4.2 K, 15 T) of 4200 A/mm(2) and JE (4.2 K, 15 T) of 830 A/mm(2) were achieved.

  8. On-line overpressure thin-layer chromatographic separation and electrospray mass spectrometric detection of glycolipids.

    PubMed

    Chai, Wengang; Leteux, Christine; Lawson, Alexander M; Stoll, Mark S

    2003-01-01

    On-line thin-layer chromatographic separation and electrospray mass spectrometry (TLC/ESI-MS) has been accomplished by direct linking of a commercial overpressure TLC instrument, OPLC 50, and a Q-TOF mass spectrometer. Mass spectrometric detection sensitivity and chromatographic resolution achieved by this configuration were assessed using acidic glycolipids as examples. Under the optimized conditions, a sensitivity of 5 pmol of glycosphingolipid was readily demonstrated for TLC/ESI-MS and 20 pmol for TLC/ESI-MS/MS production scanning to derive the saccharide sequence and long chain base/fatty acid composition of the ceramide. Initial preconditioning of TLC plates is necessary to achieve high sensitivity detection by reducing chemical background noise. Plates can be used repeatedly (at least 10 times) for analysis, although this may result in a minor reduction in TLC resolution. Following solvent development, separated components on the TLC plates can be detected in the conventional way by nondestructive staining or UV absorption or fluorescence and can be stored for on-line TLC/ESI-MS analysis at a later stage without reduction in mass spectrometric detection sensitivity and chromatographic resolution. Aspects for further improvement of OPLC instrumentation include use of narrower TLC plate dimensions and refined design of the eluate exit system.

  9. A proposed biochemical mechanism involving hemoglobin for blast overpressure-induced injury.

    PubMed

    Elsayed, N M; Gorbunov, N V; Kagan, V E

    1997-07-25

    Blast overpressure (BOP) is the abrupt, rapid, rise in atmospheric pressure resulting from explosive detonation, firing of large-caliber weapons, and accidental occupational explosions. Exposure to incident BOP waves causes internal injuries, mostly to the hollow organs, particularly the ears, lungs and gastrointestinal tract. BOP-induced injury used to be considered of military concern because it occurred mostly in military environments during military actions or training, and to a lesser extent during civilian occupational accidents. However, in recent years with the proliferation of indiscriminate terrorist bombings worldwide involving civilians, blast injury has become a societal concern, and the need to understand the biochemical and molecular mechanism(s) of injury, and to find new and effective methods for treatment gained importance. In general, past BOP research has focused on the physiological and pathological manifestations of incapacitation, thresholds of safety, and on predictive modeling. However, we have been studying the molecular mechanism of BOP-induced injury, and recently began to have an insight into that mechanism, and recognize the role of hemoglobin released during hemorrhage in catalyzing free radical reactions leading to oxidative stress. In this report we discuss the biochemical changes observed after BOP exposure in rat blood and lung tissue, and propose a biochemical mechanism for free radical-induced oxidative stress that can potentially complicate the injury. Moreover, we observed that some antioxidants can interact with Hb oxidation products (oxy-, met- and oxoferrylHb) and act as prooxidants that can increase the damage rather than decrease it.

  10. Growth of CdZnTe Crystals the Bridgman Technique with Controlled Overpressures of Cd

    NASA Technical Reports Server (NTRS)

    Su, Ching-Hu; Lehoczky, S. L.

    2008-01-01

    Cd(1-x)Zn(x)Te crystals with x = 0.15 and 0.20, were grown in this study by closed-ampoule directional solidification (Bridgman) technique with a controlled Cd overpressure. The growth ampoule was made of quartz with inner diameter from 20 to 40 mm and a tapered length of 2.5 cm at the growth tip. Both unseeded and seeded growths were performed with total material charges up to 400 g. After the loading of starting CdZnTe material, a typical amount of 2 g of Cd was also loaded inside a Cd reservoir basket, which was attached beneath the seal-off cup. The ampoule was sealed off under a vacuum below lxl0(exp -5) Torr. The sealed ampoule was placed inside a 4-zone Bridgman furnace - a Cd reservoir zone with a heat-pipe furnace liner on the top, followed by a hot zone, a booster heating zone and a cold zone at the bottom. The Cd zone was typically 300 to 400 C below the hot zone setting. High resistivity material has been obtained without any intentional dopants but has been reproducibly obtained with In doping. The crystalline and the electrical properties of the crystals will be reported.

  11. Antifungal metabolites from the roots of Diospyros virginiana by overpressure layer chromatography.

    PubMed

    Wang, Xiaoning; Habib, Eman; León, Francisco; Radwan, Mohamed M; Tabanca, Nurhayat; Gao, Jiangtao; Wedge, David E; Cutler, Stephen J

    2011-12-01

    A preparative overpressure layer chromatography (OPLC) method was successfully used for the separation of two new natural compounds, 4-hydroxy-5,6-dimethoxynaphthalene-2-carbaldehyde (1) and 12,13-didehydro-20,29-dihydrobetulin (2) together with nine known compounds, including 7-methyljuglone (3), diospyrin (4), isodiospyrin (5), shinanolone (6), lupeol (7), betulin (8), betulinic acid (9), betulinaldehyde (10), and ursolic acid (11) from the acetone extract of the roots of Diospyros virginiana. Their identification was accomplished by 1D- and 2D-NMR spectroscopy and HR-ESI-MS methods. All the isolated compounds were evaluated for their antifungal activities against Colletotrichum fragariae, C. gloeosporioides, C. acutatum, Botrytis cinerea, Fusarium oxysporum, Phomopsis obscurans, and P. viticola using in vitro micro-dilution broth assay. The results indicated that compounds 3 and 5 showed high antifungal activity against P. obscurans at 30 μM with 97.0 and 81.4% growth inhibition, and moderate activity against P. viticola (54.3 and 36.6%). It appears that an optimized OPLC system offers a rapid and efficient method of exploiting bioactive natural products. Copyright © 2011 Verlag Helvetica Chimica Acta AG, Zürich.

  12. No neurochemical evidence of brain injury after blast overpressure by repeated explosions or firing heavy weapons.

    PubMed

    Blennow, K; Jonsson, M; Andreasen, N; Rosengren, L; Wallin, A; Hellström, P A; Zetterberg, H

    2011-04-01

    Psychiatric and neurological symptoms are common among soldiers exposed to blast without suffering a direct head injury. It is not known whether such symptoms are direct consequences of blast overpressure. To examine if repeated detonating explosions or firing if of heavy weapons is associated with neurochemical evidence of brain damage. Three controlled experimental studies. In the first, army officers were exposed to repeated firing of a FH77B howitzer or a bazooka. Cerebrospinal fluid (CSF) was taken post-exposure to measure biomarkers for brain damage. In the second, officers were exposed for up to 150 blasts by firing a bazooka, and in the third to 100 charges of detonating explosives of 180 dB. Serial serum samples were taken after exposure. Results were compared with a control group consisting of 19 unexposed age-matched healthy volunteers. The CSF biomarkers for neuronal/axonal damage (tau and neurofilament protein), glial cell injury (GFAP and S-100b), blood-brain barrier damage (CSF/serum albumin ratio) and hemorrhages (hemoglobin and bilirubin) and the serum GFAP and S-100b showed normal and stable levels in all exposed officers. Repeated exposure to high-impact blast does not result in any neurochemical evidence of brain damage. These findings are of importance for soldiers regularly exposed to high-impact blast when firing artillery shells or other types of heavy weapons. © 2010 John Wiley & Sons A/S.

  13. Antifungal Metabolites from the Roots of Diospyros virginiana by Overpressure Layer Chromatography

    PubMed Central

    Wang, Xiaoning; Habib, Eman; León, Francisco; Radwan, Mohamed M.; Tabanca, Nurhayat; Gao, Jiangtao

    2011-01-01

    A preparative overpressure layer chromatography (OPLC) method was successfully used for the separation of two new natural compounds, 4-hydroxy-5,6-dimethoxy-2-naphthaldehyde (1) and Δ12,13-20,29-dihydrobetulin (2) together with nine known compounds including 7-methyl-juglone (3), diospyrin (4), isodiospyrin (5), shinanolone (6), lupeol (7), betulin (8), betulinic acid (9), betulinaldehyde (10), and ursolic acid (11) from the acetone extract of the roots of Diospyros virginiana. Their identification was performed with mono and bidimensional NMR spectroscopy and HR-ESI-MS methods. All the isolated compounds were evaluated for their antifungal activity against Colletotrichum fragariae, C. gloeosporioides, C. acutatum, Botrytis cinerea, Fusarium oxysporum, Phomopsis obscurans, and P. viticola using in vitro micro-dilution broth assay. The results indicated that compounds 3 and 5 showed high antifungal activity against P. obscurans at 30 μM with 97.0 % and 81.4 % growth inhibition and moderate activity against P. viticola (54.3 % and 36.6 %). It appears that an optimized OPLC system offers a rapid and efficient method of exploiting bioactive natural products. PMID:22162171

  14. Blast overpressure induced axonal injury changes in rat brainstem and spinal cord

    PubMed Central

    Kallakuri, Srinivasu; Purkait, Heena S.; Dalavayi, Satya; VandeVord, Pamela; Cavanaugh, John M.

    2015-01-01

    Introduction: Blast induced neurotrauma has been the signature wound in returning soldiers from the ongoing wars in Iraq and Afghanistan. Of importance is understanding the pathomechansim(s) of blast overpressure (OP) induced axonal injury. Although several recent animal models of blast injury indicate the neuronal and axonal injury in various brain regions, animal studies related to axonal injury in the white matter (WM) tracts of cervical spinal cord are limited. Objective: The purpose of this study was to assess the extent of axonal injury in WM tracts of cervical spinal cord in male Sprague Dawley rats subjected to a single insult of blast OP. Materials and Methods: Sagittal brainstem sections and horizontal cervical spinal cord sections from blast and sham animals were stained by neurofilament light (NF-L) chain and beta amyloid precursor protein immunocytochemistry and observed for axonal injury changes. Results: Observations from this preliminary study demonstrate axonal injury changes in the form of prominent swellings, retraction bulbs, and putative signs of membrane disruptions in the brainstem and cervical spinal cord WM tracts of rats subjected to blast OP. Conclusions: Prominent axonal injury changes following the blast OP exposure in brainstem and cervical spinal WM tracts underscores the need for careful evaluation of blast induced injury changes and associated symptoms. NF-L immunocytochemistry can be considered as an additional tool to assess the blast OP induced axonal injury. PMID:26752889

  15. Delineating Area of Review in a System with Pre-injection Relative Overpressure

    DOE PAGES

    Oldenburg, Curtis M.; Cihan, Abdullah; Zhou, Quanlin; ...

    2014-12-31

    The Class VI permit application for geologic carbon sequestration (GCS) requires delineation of an area of review (AoR), defined as the region surrounding the (GCS) project where underground sources of drinking water (USDWs) may be endangered. The methods for estimating AoR under the Class VI regulation were developed assuming that GCS reservoirs would be in hydrostatic equilibrium with overlying aquifers. Here we develop and apply an approach to estimating AoR for sites with preinjection relative overpressure for which standard AoR estimation methods produces an infinite AoR. The approach we take is to compare brine leakage through a hypothetical open flowmore » path in the base-case scenario (no-injection) to the incrementally larger leakage that would occur in the CO2-injection case. To estimate AoR by this method, we used semi-analytical solutions to single-phase flow equations to model reservoir pressurization and flow up (single) leaky wells located at progressively greater distances from the injection well. We found that the incrementally larger flow rates for hypothetical leaky wells located 6 km and 4 km from the injection well are ~20% and 30% greater, respectively, than hypothetical baseline leakage rates. If total brine leakage is considered, the results depend strongly on how the incremental increase in total leakage is calculated, varying from a few percent to up to 40% greater (at most at early time) than base-case total leakage.« less

  16. Prediction of blast-induced air overpressure: a hybrid AI-based predictive model.

    PubMed

    Jahed Armaghani, Danial; Hajihassani, Mohsen; Marto, Aminaton; Shirani Faradonbeh, Roohollah; Mohamad, Edy Tonnizam

    2015-11-01

    Blast operations in the vicinity of residential areas usually produce significant environmental problems which may cause severe damage to the nearby areas. Blast-induced air overpressure (AOp) is one of the most important environmental impacts of blast operations which needs to be predicted to minimize the potential risk of damage. This paper presents an artificial neural network (ANN) optimized by the imperialist competitive algorithm (ICA) for the prediction of AOp induced by quarry blasting. For this purpose, 95 blasting operations were precisely monitored in a granite quarry site in Malaysia and AOp values were recorded in each operation. Furthermore, the most influential parameters on AOp, including the maximum charge per delay and the distance between the blast-face and monitoring point, were measured and used to train the ICA-ANN model. Based on the generalized predictor equation and considering the measured data from the granite quarry site, a new empirical equation was developed to predict AOp. For comparison purposes, conventional ANN models were developed and compared with the ICA-ANN results. The results demonstrated that the proposed ICA-ANN model is able to predict blast-induced AOp more accurately than other presented techniques.

  17. CFD Assessment of Forward Booster Separation Motor Ignition Overpressure on ET XT 718 Ice/Frost Ramp

    NASA Technical Reports Server (NTRS)

    Tejnil, Edward; Rogers, Stuart E.

    2012-01-01

    Computational fluid dynamics assessment of the forward booster separation motor ignition over-pressure was performed on the space shuttle external tank X(sub T) 718 ice/frost ramp using the flow solver OVERFLOW. The main objective of this study was the investigation of the over-pressure during solid rocket booster separation and its affect on the local pressure and air-load environments. Delta pressure and plume impingement were investigated as a possible contributing factor to the cause of the debris loss on shuttle missions STS-125 and STS-127. A simplified computational model of the Space Shuttle Launch Vehicle was developed consisting of just the external tank and the solid rocket boosters with separation motor nozzles and plumes. The simplified model was validated by comparison to full fidelity computational model of the Space Shuttle without the separation motors. Quasi steady-state plume solutions were used to calibrate the thrust of the separation motors. Time-accurate simulations of the firing of the booster-separation motors were performed. Parametric studies of the time-step size and the number of sub-iterations were used to find the best converged solution. The computed solutions were compared to previous OVERFLOW steady-state runs of the separation motors with reaction control system jets and to ground test data. The results indicated that delta pressure from the overpressure was small and within design limits, and thus was unlikely to have contributed to the foam losses.

  18. 43 CFR 4730.1 - Destruction.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... HORSES AND BURROS Destruction of Wild Horses or Burros and Disposal of Remains § 4730.1 Destruction. Except as an act of mercy, no wild horse or burro shall be destroyed without the authorization of the...

  19. 43 CFR 4730.1 - Destruction.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... HORSES AND BURROS Destruction of Wild Horses or Burros and Disposal of Remains § 4730.1 Destruction. Except as an act of mercy, no wild horse or burro shall be destroyed without the authorization of the...

  20. 43 CFR 4730.1 - Destruction.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... HORSES AND BURROS Destruction of Wild Horses or Burros and Disposal of Remains § 4730.1 Destruction. Except as an act of mercy, no wild horse or burro shall be destroyed without the authorization of the...

  1. 43 CFR 4730.1 - Destruction.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... HORSES AND BURROS Destruction of Wild Horses or Burros and Disposal of Remains § 4730.1 Destruction. Except as an act of mercy, no wild horse or burro shall be destroyed without the authorization of the...

  2. Emergency Metacarpophalangeal Arthroplastywith Bone Grafting for Traumatic Joint Destruction.

    PubMed

    Pomares, G; Calafat, V; Montoya-Faivre, D; Dap, F; Dautel, G

    2017-08-05

    Emergency arthroplasty of the metacarpophalangeal joint (MCPJ) remains a valuable treatment option in patients with MCPJ destruction but may raise challenges in the event of substantial metacarpal and/or phalangeal bone defects. We report three cases ofMCPJdestruction with bone defects at the proximal first phalanx treated with emergency silicone implant arthroplasty combined with bone grafting. Copyright © 2017. Published by Elsevier Masson SAS.

  3. How to overpressurize a magmatic chamber: the thermodynamic constraints of crystallization-gas exsolution processes

    NASA Astrophysics Data System (ADS)

    Cichy, S.; Thiéry, R.

    2012-12-01

    The pressure evolution of magmatic chambers is a key question in order to understand the triggering mechanisms and conditions of volcanic eruptions. While this subject is undoubtedly complex, a first answer was provided by the seminal model of Tait et al. (1989), which addresses the pressurization produced by simultaneous crystallization-gas exsolution. Through a set of simple equations, they succeed to tackle this problem by using salient physico-chemical parameters of interest, i.e. magma nature (mafic or felsic), bulk volatile content (H2O and CO2), crystallization variation, initial magma pressure, Henry solubility coefficients, elasticity of the magmatic chamber, melt and crystal densities. Thus, Tait et al. (1989) were able to show that coeval crystallization-gas exsolution is, indeed, an efficient process: a partial crystallization of a few percent in water-saturated magmas is sufficient to generate overpressures exceeding twice the tensile strength of the magmatic chamber. However, in other cases (CO2 or some H2O-CO2 saturated magmas), this model predicts underpressures of the magma chambers, and such a result is counterintuitive and problematic from what is known in volcanology. In fact, to our knowledge, one feature of the theory of Tait et al. has never been clearly stated in the literature: this model applies only in the case of disequilibrium growth of crystals in the magma, as no provision is made to take into account the chemical equilibrium of silicate components between solids and melt. While this simplification hypothesis is certainly valid in fast-evolving magmas (kinetic effects) it may be questioned in the case of slow crystallization at equilibrium with the melt. Thus, we have extended the algorithm of Tait et al. (1989) to deal with this new aspect. The main result is that, in all cases, significant overpressures will be generated in cooling magmas (even CO2-saturated magmas). This can be explained as follows: under the equilibrium assumption

  4. Maximal exercise performance-impairing effects of simulated blast overpressure in sheep.

    PubMed

    Januszkiewicz, A J; Mundie, T G; Dodd, K T

    1997-07-25

    Lung contusion has been identified as a primary blast injury. These experiments addressed a fundamental and overt endpoint of primary blast injury, incapacitation (performance decrement). Respiration, hemodynamics, and blood gases were measured in sheep undergoing incremental exercise challenge before and 1 h after simulated blast exposure of the thorax. Pathologic examination of lung tissue was performed after exposure and exercise testing. Blast overpressure was simulated in the laboratory using a compressed air-driven shock tube. Three levels of lung injury (Levels 1-3, 'Trivial', 'Slight', and 'Moderate' injury, respectively) were examined for effects on maximal oxygen consumption (VO[2max]), an index of cardiorespiratory fitness. Resting hemodynamics and blood gases were relatively normal an hour after exposure, immediately before exercise. However, Levels 1-3 lung injury were associated with average 4.8, 29.9 and 49.3% VO(2max). decreases, respectively. These performance decrements for Levels 2 and 3 were significantly different from respective controls (non-exposed). Exercise caused significant hemoconcentration in sheep under control conditions, before exposure (resting 9.5 +/- 0.9, end-exercise 11.8 +/- 0.9 g/100 ml). Blast exposure resulted in average decreases of 4.9 +/- 3.4, 12.8 +/- 4.0, and 12.6 +/- 3.3% in exercise-induced hemoconcentration for Levels 1-3 injury, respectively. Normal exercise-induced hemodynamic increases were also attenuated after exposure. Levels 2 and 3 injury resulted in average 22.6 +/- 2.9 and 18.5 +/- 11.2% stroke volume decreases, and also 22.3 +/- 8.4 and 29.0 +/- 14.2% cardiac output decreases, respectively, during exercise. While blast lung pathology and pulmonary function changes could account for post-blast performance decrements, these experiments suggest that in sheep, early after exposure, diminished hemoconcentration and cardiac disfunction may also contribute to decreased exercise performance.

  5. The functional and structural changes in the basilar artery due to overpressure blast injury

    PubMed Central

    Toklu, Hale Z; Muller-Delp, Judy; Yang, Zhihui; Oktay, Şehkar; Sakarya, Yasemin; Strang, Kevin; Ghosh, Payal; Delp, Michael D; Scarpace, Philip J; Wang, Kevin KW; Tümer, Nihal

    2015-01-01

    Overpressure blast-wave induced brain injury (OBI) leads to progressive pathophysiologic changes resulting in a reduction in brain blood flow, blood brain barrier breakdown, edema, and cerebral ischemia. The aim of this study was to evaluate cerebral vascular function after single and repeated OBI. Male Sprague-Dawley rats were divided into three groups: Control (Naive), single OBI (30 psi peak pressure, 1 to 2 msec duration), and repeated (days 1, 4, and 7) OBI (r-OBI). Rats were killed 24 hours after injury and the basilar artery was isolated, cannulated, and pressurized (90 cm H2O). Vascular responses to potassium chloride (KCl) (30 to 100 mmol/L), endothelin-1 (10−12 to 10−7 mol/L), acetylcholine (ACh) (10−10 to 10−4 mol/L) and diethylamine-NONO-ate (DEA-NONO-ate) (10−10 to 10−4 mol/L) were evaluated. The OBI resulted in an increase in the contractile responses to endothelin and a decrease in the relaxant responses to ACh in both single and r-OBI groups. However, impaired DEA-NONO-ate-induced vasodilation and increased wall thickness to lumen ratio were observed only in the r-OBI group. The endothelin-1 type A (ETA) receptor and endothelial nitric oxide synthase (eNOS) immunoreactivity were significantly enhanced by OBI. These findings indicate that both single and r-OBI impairs cerebral vascular endothelium-dependent dilation, potentially a consequence of endothelial dysfunction and/or vascular remodelling in basilar arteries after OBI. PMID:26104291

  6. Morphologic and biochemical characterization of brain injury in a model of controlled blast overpressure exposure.

    PubMed

    Svetlov, Stanislav I; Prima, Victor; Kirk, Daniel R; Gutierrez, Hector; Curley, Kenneth C; Hayes, Ronald L; Wang, Kevin K W

    2010-10-01

    Existing experimental approaches for studies of blast impact in small animals are insufficient and lacking consistency. Here, we present a comprehensive model, with repeatable blast signatures of controlled duration, peak pressure, and transmitted impulse, accurately reproducing blast impact in laboratory animals. Rat survival, brain pathomorphology, and levels of putative biomarkers of brain injury glial fibrillary acid protein (GFAP), neuron-specific enolase, and ubiquitin C-terminal hydrolase (UCH)-L1 were examined in brain, cerebrospinal fluid (CSF), and blood after 10 msec of 358 kPa peak overpressure blast exposure. The high-speed imaging demonstrated a strong head acceleration/jolting accompanied by typical intracranial hematomas and brain swelling. Microscopic injury was revealed by prominent silver staining in deep brain areas, including the nucleus subthalamicus zone, suggesting both diffused and focal neurodegeneration. GFAP and 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase), markers of astroglia and oligodendroglia, accumulated substantially in the hippocampus 24 hours after blast and persisted for 30 days postblast. However, GFAP content in the blood significantly increased 24 hours after injury, followed by a decline and subsequent accumulation in CSF in a time-dependent fashion. A similar profile is shown for UCH-L1 increase in blood, whereas increased CSF levels of UCH-L1 persisted throughout 14 days after blast and varied significantly in individual rats. Neuron-specific enolase levels in blood were significantly elevated within 24 hours and 48 hours postblast. The proposed model of controlled nonpenetrating blast in rats demonstrates the critical pathologic and biochemical signatures of blast brain injury that may be triggered by cerebrovascular responses, including blood-brain barrier disruption, glia responses, and neuroglial alterations.

  7. The functional and structural changes in the basilar artery due to overpressure blast injury.

    PubMed

    Toklu, Hale Z; Muller-Delp, Judy; Yang, Zhihui; Oktay, Şehkar; Sakarya, Yasemin; Strang, Kevin; Ghosh, Payal; Delp, Michael D; Scarpace, Philip J; Wang, Kevin K W; Tümer, Nihal

    2015-12-01

    Overpressure blast-wave induced brain injury (OBI) leads to progressive pathophysiologic changes resulting in a reduction in brain blood flow, blood brain barrier breakdown, edema, and cerebral ischemia. The aim of this study was to evaluate cerebral vascular function after single and repeated OBI. Male Sprague-Dawley rats were divided into three groups: Control (Naive), single OBI (30 psi peak pressure, 1 to 2 msec duration), and repeated (days 1, 4, and 7) OBI (r-OBI). Rats were killed 24 hours after injury and the basilar artery was isolated, cannulated, and pressurized (90 cm H2O). Vascular responses to potassium chloride (KCl) (30 to 100 mmol/L), endothelin-1 (10(-12) to 10(-7) mol/L), acetylcholine (ACh) (10(-10) to 10(-4) mol/L) and diethylamine-NONO-ate (DEA-NONO-ate) (10(-10) to 10(-4) mol/L) were evaluated. The OBI resulted in an increase in the contractile responses to endothelin and a decrease in the relaxant responses to ACh in both single and r-OBI groups. However, impaired DEA-NONO-ate-induced vasodilation and increased wall thickness to lumen ratio were observed only in the r-OBI group. The endothelin-1 type A (ET(A)) receptor and endothelial nitric oxide synthase (eNOS) immunoreactivity were significantly enhanced by OBI. These findings indicate that both single and r-OBI impairs cerebral vascular endothelium-dependent dilation, potentially a consequence of endothelial dysfunction and/or vascular remodelling in basilar arteries after OBI.

  8. Pulmonary biochemical and histological alterations after repeated low-level blast overpressure exposures.

    PubMed

    Elsayed, Nabil M; Gorbunov, Nikolai V

    2007-01-01

    Blast overpressure (BOP), also known as high energy impulse noise, is a damaging outcome of explosive detonations and firing of weapons. Exposure to BOP shock waves alone results in injury predominantly to the hollow organ systems such as auditory, respiratory, and gastrointestinal systems. In recent years, the hazards of BOP that once were confined to military and professional settings have become a global societal problem as terrorist bombings and armed conflicts involving both military and civilian populations increased significantly. We have previously investigated the effects of single BOP exposures at different peak pressures. In this study, we examined the effects of repeated exposure to a low-level BOP and whether the number of exposures or time after exposure would alter the injury outcome. We exposed deeply anesthetized rats to simulated BOP at 62 +/- 2 kPa peak pressure. The lungs were examined immediately after one exposure (1 + 0), or 1 h after one (1 + 1), two (2 + 1), or three (3 + 1) consecutive exposures at 3-min interval. In one group of animals, we examined the effects of repeated exposure on lung weight, methemoglobin, transferrin, antioxidants, and lipid peroxidation. In a second group, the lungs were fixed inflated at 25 cm water, sectioned, and examined histologically after one to three repeated exposures, or after one exposure at 1, 6, and 24 h. We found that single BOP exposure causes notable changes after 1 h, and that repeating BOP exposure did not add markedly to the effect of the first one. However, the effects increased significantly with time from 1 to 24 h. These observations have biological and occupational implications, and emphasize the need for protection from low-level BOP, and for prompt treatment within the first hour following BOP exposure.

  9. Longitudinal variations of laryngeal overpressure and voice-related quality of life in spasmodic dysphonia.

    PubMed

    Yeung, Jeffrey C; Fung, Kevin; Davis, Eric; Rai, Sunita K; Day, Adam M B; Dzioba, Agnieszka; Bornbaum, Catherine; Doyle, Philip C

    2015-03-01

    Adductor spasmodic dysphonia (AdSD) is a voice disorder characterized by variable symptom severity and voice disability. Those with the disorder experience a wide spectrum of symptom severity over time, resulting in varied degrees of perceived voice disability. This study investigated the longitudinal variability of AdSD, with a focus on auditory-perceptual judgments of a dimension termed laryngeal overpressure (LO) and patient self-assessments of voice-related quality of life (V-RQOL). Longitudinal, correlational study. Ten adults with AdSD were followed over three time periods. At each, both voice samples and self-ratings of V-RQOL were gathered prior to their scheduled Botox injection. Voice recordings subsequently were perceptually evaluated by eight listeners for LO using a visual analog scale. LO ratings for all-voiced and Rainbow Passage sentence stimuli were found to be highly correlated. However, only the LO ratings obtained from judgments of AV stimuli were found to correlate moderately with self-ratings of voice disability for both the physical functioning and social-emotional subscores, as well as the total V-RQOL score. Based on perceptual judgments, LO appears to provide a reliable means of quantifying the severity of voice abnormalities in AdSD. Variability in self-ratings of the V-RQOL suggest that perceived disability related to AdSD should be actively monitored. Further, auditory-perceptual judgments may provide an accurate index of the potential impact of the disorder on the speaker. Similarly, LO was supported as a simple clinical measure that serves as a reliable index of voice change over time. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

  10. Enhancing Biopolymer Dynamics through Destruction

    NASA Astrophysics Data System (ADS)

    Ross, Jennifer

    2012-02-01

    Microtubules are cytoskeletal filaments that organize intracellular space structurally and through active transport along their lengths. They need to be organized and remodeled quickly during development of differentiated cells or in mitosis. Much work has focused on remodeling from the ends because these long polymers can stochastically disassemble through dynamic instability or be actively disassembled. Microtubule-severing enzymes are a novel class of microtubule regulators that create new ends by cutting the filament. Thus, these proteins add a new dimension to microtubule regulation by their ability to create new microtubule ends. Interestingly, despite their destructive capabilities, severing has the ability to create new microtubule networks in cells. We are interested in the inherent biophysical activities of these proteins and their ability to remodel cellular microtubule networks. Interestingly, despite their destructive capabilities, severing has the ability to create new microtubule networks in cells. We use two-color single molecule total internal reflection fluorescence imaging to visualize purified severing enzymes and microtubules in vitro. We have examined two families of severing enzymes to find that their biophysical activities are distinct giving them different network-regulating abilities.

  11. Indirect Self-Destructiveness and Emotional Intelligence.

    PubMed

    Tsirigotis, Konstantinos

    2016-06-01

    While emotional intelligence may have a favourable influence on the life and psychological and social functioning of the individual, indirect self-destructiveness exerts a rather negative influence. The aim of this study has been to explore possible relations between indirect self-destructiveness and emotional intelligence. A population of 260 individuals (130 females and 130 males) aged 20-30 (mean age of 24.5) was studied by using the Polish version of the chronic self-destructiveness scale and INTE, i.e., the Polish version of the assessing emotions scale. Indirect self-destructiveness has significant correlations with all variables of INTE (overall score, factor I, factor II), and these correlations are negative. The intensity of indirect self-destructiveness differentiates significantly the height of the emotional intelligence and vice versa: the height of the emotional intelligence differentiates significantly the intensity of indirect self-destructiveness. Indirect self-destructiveness has negative correlations with emotional intelligence as well as its components: the ability to recognize emotions and the ability to utilize emotions. The height of emotional intelligence differentiates the intensity of indirect self-destructiveness, and vice versa: the intensity of indirect self-destructiveness differentiates the height of emotional intelligence. It seems advisable to use emotional intelligence in the prophylactic and therapeutic work with persons with various types of disorders, especially with the syndrome of indirect self-destructiveness.

  12. Destruction of chemical warfare agents using metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Mondloch, Joseph E.; Katz, Michael J.; Isley, William C., III; Ghosh, Pritha; Liao, Peilin; Bury, Wojciech; Wagner, George W.; Hall, Morgan G.; Decoste, Jared B.; Peterson, Gregory W.; Snurr, Randall Q.; Cramer, Christopher J.; Hupp, Joseph T.; Farha, Omar K.

    2015-05-01

    Chemical warfare agents containing phosphonate ester bonds are among the most toxic chemicals known to mankind. Recent global military events, such as the conflict and disarmament in Syria, have brought into focus the need to find effective strategies for the rapid destruction of these banned chemicals. Solutions are needed for immediate personal protection (for example, the filtration and catalytic destruction of airborne versions of agents), bulk destruction of chemical weapon stockpiles, protection (via coating) of clothing, equipment and buildings, and containment of agent spills. Solid heterogeneous materials such as modified activated carbon or metal oxides exhibit many desirable characteristics for the destruction of chemical warfare agents. However, low sorptive capacities, low effective active site loadings, deactivation of the active site, slow degradation kinetics, and/or a lack of tailorability offer significant room for improvement in these materials. Here, we report a carefully chosen metal-organic framework (MOF) material featuring high porosity and exceptional chemical stability that is extraordinarily effective for the degradation of nerve agents and their simulants. Experimental and computational evidence points to Lewis-acidic ZrIV ions as the active sites and to their superb accessibility as a defining element of their efficacy.

  13. Destruction of chemical warfare agents using metal-organic frameworks.

    PubMed

    Mondloch, Joseph E; Katz, Michael J; Isley, William C; Ghosh, Pritha; Liao, Peilin; Bury, Wojciech; Wagner, George W; Hall, Morgan G; DeCoste, Jared B; Peterson, Gregory W; Snurr, Randall Q; Cramer, Christopher J; Hupp, Joseph T; Farha, Omar K

    2015-05-01

    Chemical warfare agents containing phosphonate ester bonds are among the most toxic chemicals known to mankind. Recent global military events, such as the conflict and disarmament in Syria, have brought into focus the need to find effective strategies for the rapid destruction of these banned chemicals. Solutions are needed for immediate personal protection (for example, the filtration and catalytic destruction of airborne versions of agents), bulk destruction of chemical weapon stockpiles, protection (via coating) of clothing, equipment and buildings, and containment of agent spills. Solid heterogeneous materials such as modified activated carbon or metal oxides exhibit many desirable characteristics for the destruction of chemical warfare agents. However, low sorptive capacities, low effective active site loadings, deactivation of the active site, slow degradation kinetics, and/or a lack of tailorability offer significant room for improvement in these materials. Here, we report a carefully chosen metal-organic framework (MOF) material featuring high porosity and exceptional chemical stability that is extraordinarily effective for the degradation of nerve agents and their simulants. Experimental and computational evidence points to Lewis-acidic Zr(IV) ions as the active sites and to their superb accessibility as a defining element of their efficacy.

  14. Evaluation of brain tissue responses because of the underwash overpressure of helmet and faceshield under blast loading.

    PubMed

    Sarvghad-Moghaddam, Hesam; Rezaei, Asghar; Ziejewski, Mariusz; Karami, Ghodrat

    2017-01-01

    Head protective tools such as helmets and faceshields can induce a localized high pressure region on the skull because of the underwash of the blast waves. Whether this underwash overpressure can affect the brain tissue response is still unknown. Accordingly, a computational approach was taken to confirm the incidence of underwash with regards to blast direction, as well as examine the influence of this effect on the mechanical responses of the brain. The variation of intracranial pressure (ICP) as one of the major injury predictors, as well as the maximum shear stress were mainly addressed in this study. Using a nonlinear finite element (FE) approach, generation and interaction of blast waves with the unprotected, helmeted, and fully protected (helmet and faceshield protected) FE head models were modeled using a multi-material arbitrary Lagrangian-Eulerian (ALE) method and a fluid-structure interaction (FSI) coupling algorithm. The underwash incidence overpressure was found to greatly change with the blast direction. Moreover, while underwash induced ICP (U-ICP) did not exceed the peak ICP of the unprotected head, it was comparable and even more than the peak ICP imposed on the protected heads by the primary shockwaves (Coup-ICP). It was concluded that while both helmet and faceshield protected the head against blast waves, the underwash overpressure affected the brain tissue response and altered the dynamic load experienced by the brain as it led to increased ICP levels at the countercoup site, imparted elevated skull flexure, and induced high negative pressure regions. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  15. Pathophysiology of blast-induced ocular trauma in rats after repeated exposure to low-level blast overpressure.

    PubMed

    Choi, Jae Hyek; Greene, Whitney A; Johnson, Anthony J; Chavko, Mikulas; Cleland, Jeffery M; McCarron, Richard M; Wang, Heuy-Ching

    2015-04-01

    The incidence of blast-induced ocular injury has dramatically increased due to advances in weaponry and military tactics. A single exposure to blast overpressure (BOP) has been shown to cause damage to the eye in animal models; however, on the battlefield, military personnel are exposed to BOP multiple times. The effects of repeated exposures to BOP on ocular tissues have not been investigated. The purpose of this study is to characterize the effects of single or repeated exposure on ocular tissues. A compressed air shock tube was used to deliver 70 ± 7 KPa BOP to rats, once (single blast overpressure [SBOP]) or once daily for 5 days (repeated blast overpressure [RBOP]). Immunohistochemistry was performed to characterize the pathophysiology of ocular injuries induced by SBOP and RBOP. Apoptosis was determined by quantification activated caspase 3. Gliosis was examined by detection of glial fibrillary acidic protein (GFAP). Inflammation was examined by detection of CD68. Activated caspase 3 was detected in ocular tissues from all animals subjected to BOP, while those exposed to RBOP had more activated caspase 3 in the optic nerve than those exposed to SBOP. GFAP was detected in the retinas from all animals subjected to BOP. CD68 was detected in optic nerves from all animals exposed to BOP. SBOP and RBOP induced retinal damage. RBOP caused more apoptosis in the optic nerve than SBOP, suggesting that RBOP causes more severe optic neuropathy than SBOP. SBOP and RBOP caused gliosis in the retina and increased inflammation in the optic nerve. © 2014 Royal Australian and New Zealand College of Ophthalmologists.

  16. Mechanisms of contrast agent destruction.

    PubMed

    Chomas, J E; Dayton, P; Allen, J; Morgan, K; Ferrara, K W

    2001-01-01

    Various applications of contrast-assisted ultrasound, including blood vessel detection, perfusion estimation, and drug delivery, require controlled destruction of contrast agent microbubbles. The lifetime of a bubble depends on properties of the bubble shell, the gas core, and the acoustic waveform impinging on the bubble. Three mechanisms of microbubble destruction are considered: fragmentation, acoustically driven diffusion, and static diffusion. Fragmentation is responsible for rapid destruction of contrast agents on a time scale of microseconds. The primary characteristics of fragmentation are a very large expansion and subsequent contraction, resulting in instability of the bubble. Optical studies using a novel pulsed-laser optical system show the expansion and contraction of ultrasound contrast agent microbubbles with the ratio of maximum diameter to minimum diameter greater than 10. Fragmentation is dependent on the transmission pressure, occurring in over 55% of bubbles insonified with a peak negative transmission pressure of 2.4 MPa and in less than 10% of bubbles insonified with a peak negative transmission pressure of 0.8 MPa. The echo received from a bubble decorrelates significantly within two pulses when the bubble is fragmented, creating an opportunity for rapid detection of bubbles via a decorrelation-based analysis. Preliminary findings with a mouse tumor model verify the occurrence of fragmentation in vivo. A much slower mechanism of bubble destruction is diffusion, which is driven by both a concentration gradient between the concentration of gas in the bubble compared with the concentration of gas in the liquid, as well as convective effects of motion of the gas-liquid interface. The rate of diffusion increases during insonation, because of acoustically driven diffusion, producing changes in diameter on the time scale of the acoustic pulse length, thus, on the order of microseconds. Gas bubbles diffuse while they are not being insonified, termed

  17. Tank 48 Chemical Destruction - 13237

    SciTech Connect

    Simner, Steven P.; Aponte, Celia I.; Brass, Earl A.

    2013-07-01

    Small tank copper-catalyzed peroxide oxidation (CCPO) is a potentially viable technology to facilitate the destruction of tetraphenylborate (TPB) organic solids contained within the Tank 48H waste at the Savannah River Site (SRS). A maturation strategy was created that identified a number of near-term development activities required to determine the viability of the CCPO process, and subsequent disposition of the CCPO effluent. Critical activities included laboratory scale validation of the process and identification of forward transfer paths for the CCPO effluent. The technical documentation and the successful application of the CCPO process on simulated Tank 48 waste confirm that the CCPO process is a viable process for the disposition of the Tank 48 contents. (authors)

  18. Non-Destructive Testing Scanner

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Bio-Imaging Research's technology that originated in an aerospace program has come full circle with a new aerospace adaptation called the Advanced Computed Tomography Inspection System, or ACTIS. The medical version of CT scans the human body for tumors or other abnormalities, the ACTIS system finds imperfections in aerospace structures and components, such as castings, assemblies, rocket motors and nozzles. ACTIS is described by its developer as the most versatile CT scanner available for non-destructive testing applications. ACTIS is a variable geometry system. ACTIS source and detectors can be moved closer together or farther apart to optimize the geometry for different sizes of test objects. The combination of variable geometry, three sources, and focusing detectors makes ACTIS cost effective for a broad range of applications. System can scan anything from very small turbine blades to large rocket assemblies.

  19. Mediated electrochemical hazardous waste destruction

    SciTech Connect

    Hickman, R.G.; Farmer, J.C.; Wang, F.T.

    1991-08-01

    There are few permitted processes for mixed waste (radioactive plus chemically hazardous) treatment. We are developing electrochemical processes that convert the toxic organic components of mixed waste to water, carbon dioxide, an innocuous anions such as chloride. Aggressive oxidizer ions such as Ag{sup 2+} or Ce{sup +4} are produced at an anode. These can attack the organic molecules directly. They can also attack water which yields hydroxyl free radicals that in turn attack the organic molecules. The condensed (i.e., solid and/or liquid) effluent streams contain the inorganic radionuclide forms. These may be treated with existing technology and prepared for final disposal. Kinetics and the extent of destruction of some toxic organics have been measured. Depending on how the process is operated, coulombic efficiency can be nearly 100%. In addition, hazardous organic materials are becoming very expensive to dispose of and when they are combined with transuranic radioactive elements no processes are presently permitted. Mediated electrochemical oxidation is an ambient-temperature aqueous-phase process that can be used to oxidize organic components of mixed wastes. Problems associated with incineration, such as high-temperature volatilization of radionuclides, are avoided. Historically, Ag (2) has been used as a mediator in this process. Fe(6) and Co(3) are attractive alternatives to Ag(2) since they form soluble chlorides during the destruction of chlorinated solvents. Furthermore, silver itself is a toxic heavy metal. Quantitative data has been obtained for the complete oxidation of ethylene glycol by Fe(6) and Co(3). Though ethylene glycol is a nonhalogenated organic, this data has enabled us to make direct comparisons of activities of Fe(6) and Co(3) with Ag(2). Very good quantitative data for the oxidation of ethylene glycol by Ag(2) had already been collected. 4 refs., 6 figs.

  20. Antioxidant depletion, lipid peroxidation, and impairment of calcium transport induced by air-blast overpressure in rat lungs.

    PubMed

    Elsayed, N M; Tyurina, Y Y; Tyurin, V A; Menshikova, E V; Kisin, E R; Kagan, V E

    1996-01-01

    Exposure to blast overpressure, or the sudden rise in atmospheric pressure after explosive detonation, results in damage mainly of the gas-filled organs. In addition to the physical damage, in the lung, injury may proceed via a hemorrhage-dependent mechanism initiating oxidative stress and accumulation of lipid peroxidation products. Massive rupture of capillaries and red blood cells, release of hemoglobin, its oxidation to met-hemoglobin and degradation sets the stage for heme-catalyzed oxidations. The authors hypothesized that lipid hydroperoxides interact with met-hemoglobin in the lungs of exposed animals to produce ferryl-hemoglobin, an extremely potent oxidant that induces oxidative damage by depleting antioxidants and initiating peroxidation reactions. Oxidation-induced disturbance of Ca2+ homeostasis facilitates further amplification of the damage. To test this hypothesis, groups of anesthetized rats (6 rats/group) were exposed to blast at 3 peak pressures: low (61.2 kPa), medium (95.2 kPa), high (136 kPa). One group served as an unexposed control. Immediately after exposure, the rats were euthanized and the lungs were analyzed for biochemical parameters. Blast overpressure caused: (1) depletion of total and water-soluble pulmonary antioxidant reserves and individual antioxidants (ascorbate, vitamin E, GSH), (2) accumulation of lipid peroxidation products (conjugated dienes, TBARS), and (3) inhibition of ATP-dependent Ca2+ transport. The magnitude of these changes in the lungs was proportional to the peak blast overpressure. Inhibition of Ca2+ transport strongly correlated with both depletion of antioxidants and enhancement of lipid peroxidation. In model experiments, met-hemoglobin/H2O2 produced damage to Ca2+ transport in the lungs from control animals similar to that observed in the lungs from blast overpressure-exposed animals. Ascorbate, which is known to reduce ferryl-hemoglobin, protected against met-hemoglobin/H2O2-induced damage of Ca2+ transport

  1. Maintaining sevoflurane anesthesia during low-flow anesthesia using a single vaporizer setting change after overpressure induction.

    PubMed

    Hendrickx, J F; Vandeput, D M; De Geyndt, A M; De Ridder, K P; Haenen, J S; Deloof, T; De Wolf, A M

    2000-06-01

    A sevoflurane vaporizer dial setting of 1.9% was previously found to maintain the end-expired sevoflurane concentration (Et(sevo)) at 1.3% during maintenance of anesthesia for procedures up to one hour with an O(2) FGF of 1 L/min. We examined whether applying these parameters could simplify low-flow sevoflurane anesthesia after overpressure induction using two slightly different techniques. Prospective clinical study. Large teaching hospital. Sixteen patients receiving general anesthesia for a variety of peripheral procedures. Anesthesia was induced with overpressure with sevoflurane (8%) in an 8 L. min(-1) O(2)/N(2)O mixture (30%/70%). After a laryngeal mask airway (LMA) was placed, fresh gas flow (FGF) was lowered to 1 L. min(-1) using O(2) and N(2)O (FiO(2) 30%) with patients breathing spontaneously. In group I patients (n = 8), the vaporizer dial was set at 1.9% at the same time the FGF was lowered. In group II patients (n = 8), the vaporizer was turned off until Et(sevo) had decreased to 1.3%, after which the dial was set at 1.9%. The course of Et(sevo) in the two groups was examined. In group I, Et(sevo) after 3 min was 4.88 +/- 1. 12%. Et(sevo) decreased slowly after reduction of FGF to 1.83 +/- 0. 19%, 1.59 +/- 0.18%, and 1.52 +/- 0.19% at 10, 20, and 30 min, respectively. In group II, Et(sevo) after 3 min was 4.34 +/- 0.84%, and decreased more rapidly after reduction of FGF to 1 L. min(-1) than in group I. Et(sevo) was 1.40 +/- 0.09%, 1.40 +/- 0.11%, and 1. 38 +/- 0.13% at 10, 20, and 30 min, respectively. After high-flow overpressure induction with sevoflurane, a single change in vaporizer setting (to 1.9%) and FGF (to 1 L. min(-1)) suffices for the Et(sevo) to approach the predicted Et(sevo) (1.3%) within 10-15 min; thereafter the Et(sevo) remains nearly constant. As expected, the predicted Et(sevo) is attained slightly faster when the vaporizer is temporarily turned off. Clinically applying previously derived pharmacokinetic parameters simplifies low

  2. Rat Injury Model under Controlled Field-Relevant Primary Blast Conditions: Acute Response to a Wide Range of Peak Overpressures

    PubMed Central

    Skotak, Maciej; Wang, Fang; Alai, Aaron; Holmberg, Aaron; Harris, Seth; Switzer, Robert C.

    2013-01-01

    Abstract We evaluated the acute (up to 24 h) pathophysiological response to primary blast using a rat model and helium driven shock tube. The shock tube generates animal loadings with controlled pure primary blast parameters over a wide range and field-relevant conditions. We studied the biomechanical loading with a set of pressure gauges mounted on the surface of the nose, in the cranial space, and in the thoracic cavity of cadaver rats. Anesthetized rats were exposed to a single blast at precisely controlled five peak overpressures over a wide range (130, 190, 230, 250, and 290 kPa). We observed 0% mortality rates in 130 and 230 kPa groups, and 30%, 24%, and 100% mortality rates in 190, 250, and 290 kPa groups, respectively. The body weight loss was statistically significant in 190 and 250 kPa groups 24 h after exposure. The data analysis showed the magnitude of peak-to-peak amplitude of intracranial pressure (ICP) fluctuations correlates well with mortality rates. The ICP oscillations recorded for 190, 250, and 290 kPa are characterized by higher frequency (10–20 kHz) than in other two groups (7–8 kHz). We noted acute bradycardia and lung hemorrhage in all groups of rats subjected to the blast. We established the onset of both corresponds to 110 kPa peak overpressure. The immunostaining against immunoglobulin G (IgG) of brain sections of rats sacrificed 24-h post-exposure indicated the diffuse blood-brain barrier breakdown in the brain parenchyma. At high blast intensities (peak overpressure of 190 kPa or more), the IgG uptake by neurons was evident, but there was no evidence of neurodegeneration after 24 h post-exposure, as indicated by cupric silver staining. We observed that the acute response as well as mortality is a non-linear function over the peak overpressure and impulse ranges explored in this work. PMID:23362798

  3. Analogue modelling of caprock failure and sediment mobilisation due to pore fluid overpressure in shallow reservoirs

    NASA Astrophysics Data System (ADS)

    Warsitzka, Michael; Kukowski, Nina; May, Franz

    2017-04-01

    Injection of CO2 in geological formations may cause excess pore fluid pressure by enhancing the fluid volume in the reservoir rock and by buoyancy-driven flow. If sediments in the reservoir and the caprock are undercompacted, pore fluid overpressure can lead to hydro-fractures in the caprock and fluidisation of sediments. Eventually, these processes trigger the formation of pipe structures, gas chimneys, gas domes or sand injections. Generally, such structures serve as high permeable pathways for fluid migration through a low-permeable seal layer and have to be considered in risk assessment or modelling of caprock integrity of CO2 storage sites. We applied scaled analogue experiments to characterise and quantify mechanisms determining the onset and migration of hydro-fractures in a low-permeable, cohesive caprock and fluidisation of unconsolidated sediments of the reservoir layer. The caprock is simulated by different types of cohesive powder. The reservoir layer consists of granulates with small particle density. Air injected through the base of the experiment and additionally through a single needle valve reaching into the analogue material is applied to generate fluid pressure within the materials. With this procedure, regional fluid pressure increase or a point-like local fluid pressure increase (e.g. injection well), respectively, can be simulated. The deformation in the analogue materials is analysed with a particle tracking imaging velocimetry technique. Pressure sensors at the base of the experiment and in the needle valve record the air pressure during an experimental run. The structural evolution observed in the experiments reveal that the cohesive cap rock first forms a dome-like anticline. Extensional fractures occur at the hinges of the anticline. A further increase of fluid pressure causes a migration of this fractures towards the surface, which is followed by intrusion of reservoir material into the fractures and the collapse of the anticline. The

  4. Destruction of polyvinyl chloride under extrusion

    NASA Astrophysics Data System (ADS)

    Dmitriev, M. T.; Serebriakova, R. V.; Serebriakov, V. N.; Zimin, P. N.; Nastenko, A. V.; Derevianchenko, L. G.; Antsifirova, N. P.; Visloukh, V. V.

    1982-08-01

    An common industrial application of polyvinyl chloride (PVC) is the extrusive insulation of electric wires and cables. Experimental results are presented on the thermal and mechanical destruction of PVC under extrusion. Under extrusion conditions (at temperatures higher than 150 C), the evolution of hydrogen chloride determines practically the entire process of PVC destruction. The use of the present data to establish hygienic standards regarding safe concentrations of PVC destruction products in the work environment is discussed.

  5. Meteorology: are there trends in hurricane destruction?

    PubMed

    Pielke, Roger A

    2005-12-22

    Since the record impact of Hurricane Katrina, attention has focused on understanding trends in hurricanes and their destructive potential. Emanuel reports a marked increase in the potential destructiveness of hurricanes based on identification of a trend in an accumulated annual index of power dissipation in the North Atlantic and western North Pacific since the 1970s. If hurricanes are indeed becoming more destructive over time, then this trend should manifest itself in more destruction. However, my analysis of a long-term data set of hurricane losses in the United States shows no upward trend once the data are normalized to remove the effects of societal changes.

  6. Photocatalytic destruction of trichloroethylene in air

    SciTech Connect

    Jacoby, W.A.; Nimlos, M.R.; Blake, D.M.

    1993-12-31

    Trichlorethylene (TCE) in air reacts in contact with irradiated TiO{sub 2} to form carbon dioxide and hydrogen chloride as well as the following products: dichloroacethylchloride, phosgene, carbon dioxide, and molecular chlorine. The stoichiometry of the reaction will be discussed and a Langmuir-Hinshelwood rate expression relating the TCE destruction rate to the partial pressures of TCE and oxygen will be presented. The reaction has been studied in both the differential and integral modes. The reaction rate and product distribution have been investigated as a function of water vapor partial pressure as well as the intensity and wavelength of the UV light. The apparatus employs annular and flat photoreactors with thin films of TiO{sub 2}. All effluent from the photoreactors flows directly into a 10 meter path length cell in an Fourier Transform Infra-Red spectrometer. This allows accurate and precise determination of reaction products (except chlorine) as evidenced by excellent carbon balances, event at very high conversions.

  7. Research on the water hammer protection of the long distance water supply project with the combined action of the air vessel and over-pressure relief valve

    NASA Astrophysics Data System (ADS)

    Li, D. D.; Jiang, J.; Zhao, Z.; Yi, W. S.; Lan, G.

    2013-12-01

    We take a concrete pumping station as an example in this paper. Through the calculation of water hammer protection with a specific pumping station water supply project, and the analysis of the principle, mathematical models and boundary conditions of air vessel and over-pressure relief valve we show that the air vessel can protect the water conveyance system and reduce the transient pressure damage due to various causes. Over-pressure relief valve can effectively reduce the water hammer because the water column re-bridge suddenly stops the pump and prevents pipeline burst. The paper indicates that the combination set of air vessel and over-pressure relief valve can greatly reduce the quantity of the air valve and can eliminate the water hammer phenomenon in the pipeline system due to the vaporization and water column separation and re-bridge. The conclusion could provide a reference for the water hammer protection of long-distance water supply system.

  8. Laser-induced propagation and destruction of amyloid beta fibrils.

    PubMed

    Yagi, Hisashi; Ozawa, Daisaku; Sakurai, Kazumasa; Kawakami, Toru; Kuyama, Hiroki; Nishimura, Osamu; Shimanouchi, Toshinori; Kuboi, Ryoichi; Naiki, Hironobu; Goto, Yuji

    2010-06-18

    The amyloid deposition of amyloid beta (Abeta) peptides is a critical pathological event in Alzheimer disease (AD). Preventing the formation of amyloid deposits and removing preformed fibrils in tissues are important therapeutic strategies against AD. Previously, we reported the destruction of amyloid fibrils of beta(2)-microglobulin K3 fragments by laser irradiation coupled with the binding of amyloid-specific thioflavin T. Here, we studied the effects of a laser beam on Abeta fibrils. As was the case for K3 fibrils, extensive irradiation destroyed the preformed Abeta fibrils. However, irradiation during spontaneous fibril formation resulted in only the partial destruction of growing fibrils and a subsequent explosive propagation of fibrils. The explosive propagation was caused by an increase in the number of active ends due to breakage. The results not only reveal a case of fragmentation-induced propagation of fibrils but also provide insights into therapeutic strategies for AD.

  9. Optimal control of fuel overpressure in a polymer electrolyte membrane fuel cell with hydrogen transfer leak during load change

    NASA Astrophysics Data System (ADS)

    Ebadighajari, Alireza; DeVaal, Jake; Golnaraghi, Farid

    2017-02-01

    Formation of membrane pinholes is a common defect in fuel cells, inflicting more cost and making less durable cells. This work focuses on mitigating this issue, and offers a continuous online treatment instead of attempting to dynamically model the hydrogen transfer leak rate. This is achieved by controlling the differential pressure between the anode and cathode compartments at the inlet side of the fuel cell stack, known as the fuel overpressure. The model predictive control approach is used to attain the objectives in a Ballard 9-cell Mk1100 polymer electrolyte membrane fuel cell (PEMFC) with inclusion of hydrogen transfer leak. Furthermore, the pneumatic modeling technique is used to model the entire anode side of a fuel cell station. The hydrogen transfer leak is embedded in the model in a novel way, and is considered as a disturbance during the controller design. Experimental results for different sizes of hydrogen transfer leaks are provided to show the benefits of fuel overpressure control system in alleviating the effects of membrane pinholes, which in turn increases membrane longevity, and reduces hydrogen emissions in the eventual presence of transfer leaks. Moreover, the model predictive controller provides an optimal control input while satisfying the problem constraints.

  10. Jonah field, sublette county, Wyoming: Gas production from overpressured Upper Cretaceous Lance sandstones of the Green River basin

    USGS Publications Warehouse

    Montgomery, S.L.; Robinson, J.W.

    1997-01-01

    Jonah field, located in the northwestern Green River basin, Wyoming, produces gas from overpressured fluvial channel sandstones of the Upper Cretaceous Lance Formation. Reservoirs exist in isolated and amalgamated channel facies 10-100 ft (3-30 m) thick and 150-4000 ft (45-1210 m) wide, deposited by meandering and braided streams. Compositional and paleocurrent studies indicate these streams flowed eastward and had their source area in highlands associated with the Wyoming-Idaho thrust belt to the west. Productive sandstones at Jonah have been divided into five pay intervals, only one of which (Jonah interval) displays continuity across most of the field. Porosities in clean, productive sandstones range from 8 to 12%, with core permeabilities of .01-0.9 md (millidarcys) and in-situ permeabilities as low as 3-20 ??d (microdarcys), as determined by pressure buildup analyses. Structurally, the field is bounded by faults that have partly controlled the level of overpressuring. This level is 2500 ft (758 m) higher at Jonah field than in surrounding parts of the basin, extending to the top part of the Lance Formation. The field was discovered in 1975, but only in the 1990s did the area become fully commercial, due to improvements in fracture stimulation techniques. Recent advances in this area have further increased recoverable reserves and serve as a potential example for future development of tight gas sands elsewhere in the Rocky Mountain region.

  11. Impact of blast induced transitory vibration and air-overpressure/noise on human brain--an experimental study.

    PubMed

    Raina, A K; Baheti, M; Haldar, A; Ramulu, M; Chakraborty, A K; Sahu, P B; Bandopadhayay, C

    2004-04-01

    Human response to blast induced ground vibration and air-overpressure/noise is a major concern of current mining activity. This is because the fact that mines are fast transgressing the habitats and people are getting educated. Consequently the response of humans is changing and expectedly will increase in days to come with no viable and economic alternative to blasting--an essential component of mining. The response of humans can be purely physiological or psychological in nature or combination of both depending upon the situation and conditions of mining. Where physiological response is documented in terms of effects on ears and lungs there is a meager amount or no literature available regarding effects of blasting on the brain. Moreover, the studies on transitory phenomenon like the effects of blasting on humans are rare in comparison to the whole body vibration studies. This study was designed to address the issues as a precursor to a major initiative. The preliminary investigations conducted with the monitoring of EEG responses of humans to vibration and air-overpressure/noise due to blasting revealed that there is no major response of the brain to transitory vibrations and noise.

  12. Alteration Behavior of High Burnup Spent Fuel in Salt Brine Under Hydrogen Overpressure and in Presence of Bromide

    SciTech Connect

    Loida, Andreas; Metz, Volker; Kienzler, Bernhard

    2007-07-01

    Recent studies have shown that in the presence of H2 overpressure, which forms due to the corrosion of the Fe based container, the dissolution rate of the spent fuel matrix is slowed down by a factor of about 10, associated with a distinct decrease of concentrations of important radionuclides. However, in a natural salt environment as well as in geological formations with chloride rich groundwater the presence of radiation chemically active impurities such as bromide must be taken in consideration. Bromide is known to react with {beta}/{gamma} radiolysis products, thus counteracting the protective H{sub 2} effect. In the present experiments using high burnup spent fuel, it is observed that during 212 days the matrix dissolution rate was enhanced by a factor of about 10 in the presence of up to 10{sup -3} M bromide and 3.2 bar H{sub 2} overpressure. However, concentrations of matrix bound actinides were found at the same level or below as found under identical conditions, but in the absence of bromide. In the long-term it is expected that the effect of bromide becomes less important, because the decrease of {beta}/{gamma}-activity results in a decrease of oxidative radicals, which react with bromide, while a-activity will dominate the radiation field. (authors)

  13. 3D integrated geophysical modeling for the 2008 magma intrusion at Etna: Constraints on rheology and dike overpressure

    NASA Astrophysics Data System (ADS)

    Currenti, Gilda; Napoli, Rosalba; Di Stefano, Agnese; Greco, Filippo; Del Negro, Ciro

    2011-03-01

    We present a 3D numerical model based on Finite Element Method (FEM) to jointly evaluate geophysical changes caused by dislocation and overpressure sources in volcanic areas. A coupled numerical problem was solved to estimate ground deformation, gravity and magnetic changes produced by stress redistribution accompanying magma migration within the volcano edifice. We successfully applied the integrated numerical procedure to image the magmatic intrusion occurring in the northern flank of Etna during the onset of the 2008 eruption. A multi-layered crustal structure of the volcano constrained by geological models and geophysical data was considered. Geodetic and gravity data provide information on the strain field, while piezomagnetic changes give constraints on the stress field. Therefore, the integrated modeling gives insights on Mt Etna rheology and dike overpressure involved in the magma propagation and improves understanding of dike emplacement in the northern sector of the volcano. Our FEM-based approach improves the reliability of model-based inference of geophysical parameters obtained during monitoring of the onset of Etna lateral intrusions that can prelude to an impending eruption.

  14. Optimal Control of Shock Tube Flow via Water Addition with Application to Ignition Overpressure Mitigation in Launch Vehicles

    NASA Astrophysics Data System (ADS)

    Moshman, Nathan

    2009-11-01

    Ignition Overpressure (IOP) in launch vehicles occurs at the start of ignition when a steep rise in pressure propagates outward from the rocket nozzle. It is crucial to minimize the overpressure so as to decrease risk of damage to the rocket body. Currently, CFD studies exist on this situation but there are no optimization studies of the water addition as a means to suppress the IOP. The proposed dissertation will use a numerical method to compute an approximate solution for an optimal control problem constrained by the one-dimensional Euler PDEs of fluid dynamics as well as volume fraction conservation. A model for inter-phase transport of mass momentum and energy and fluid interface quantities will be given. The control will be water addition from external nozzles. The adjoint system of equations will be derived and discretized. Necessary optimal conditions will be derived. An SQP method will solve an optimal situation. Predictions will be validated against shock tube experiments at the NPS rocket lab.

  15. Extinction events can accelerate evolution.

    PubMed

    Lehman, Joel; Miikkulainen, Risto

    2015-01-01

    Extinction events impact the trajectory of biological evolution significantly. They are often viewed as upheavals to the evolutionary process. In contrast, this paper supports the hypothesis that although they are unpredictably destructive, extinction events may in the long term accelerate evolution by increasing evolvability. In particular, if extinction events extinguish indiscriminately many ways of life, indirectly they may select for the ability to expand rapidly through vacated niches. Lineages with such an ability are more likely to persist through multiple extinctions. Lending computational support for this hypothesis, this paper shows how increased evolvability will result from simulated extinction events in two computational models of evolved behavior. The conclusion is that although they are destructive in the short term, extinction events may make evolution more prolific in the long term.

  16. Extinction Events Can Accelerate Evolution

    PubMed Central

    Lehman, Joel; Miikkulainen, Risto

    2015-01-01

    Extinction events impact the trajectory of biological evolution significantly. They are often viewed as upheavals to the evolutionary process. In contrast, this paper supports the hypothesis that although they are unpredictably destructive, extinction events may in the long term accelerate evolution by increasing evolvability. In particular, if extinction events extinguish indiscriminately many ways of life, indirectly they may select for the ability to expand rapidly through vacated niches. Lineages with such an ability are more likely to persist through multiple extinctions. Lending computational support for this hypothesis, this paper shows how increased evolvability will result from simulated extinction events in two computational models of evolved behavior. The conclusion is that although they are destructive in the short term, extinction events may make evolution more prolific in the long term. PMID:26266804

  17. Destruction of chlorofluorocarbons and halons

    SciTech Connect

    Matchett, J.M.; Miller, K.B.; Purcell, C.W.

    1995-06-01

    The Montreal Protocol on Substances that Deplete the Ozone Layer requires the phaseout of ozone-depleting substances in most developed countries by January 1, 1996. Developing, or Article 5, countries have been allowed additional time in which to produce these chemicals. Contrary to the Protocol`s intent, current estimates indicate that production of these chemicals by Article 5 countries could easily equal that of the developed world before their production is required to be eliminated. The Montreal Protocol also requires that used chlorofluorcarbons (CFCs) and halons are disposed of in an environmentally acceptable manner. One mechanism devised by the Montreal Protocol to reduce the amount of ozone-depleting substances that may need to be destroyed is to transfer those chemicals to Article 5 countries. Theoretically, this has the added benefit of also eliminating the need for additional production by those countries. This paper discusses the major issues associated with the disposal/destruction of ozone-depleting substances, including the transfer of these chemicals to Article 5 countries. Potential implications of the barriers to ozone-depleting substance transfer on the viability of the Montreal Protocol will also be discussed.

  18. Weapons of mass destruction, WMD.

    PubMed

    Vogel, H

    2007-08-01

    Since the invasion into Iraq in 2003, weapons of mass destruction (WMD), have come to general notice; they include today chemical, biological, and atomic/nuclear weapons, (CW, BW, and AW). Radiological findings shall be described. X-ray findings of victims of WMD are described. From CW, own observations are reported. Examples of (possible) X-ray findings of victims of BW are described. AW may induce radiation disease. Exposure to sulfur-lost induces severe bronchitis; if the radiograph shows pulmonary infiltrations, the prognosis is bad; a late consequence maybe bronchiectasis. BW can be based on bacteria, virus or toxins. An approach of the X-ray findings for BW victims is based on the assumption that the disease induced by BW has the same (or a similar) clinic and radiology as that induced by the original microorganism or by the unchanged toxism. This approximation may have its limits, if the germ or toxin has been modified. In survivors of AW, the radiology is probably that of victims of thermal radiation and blast. WMD seem to be a real or a possible threat. They can be used in war, in terrorist attacks, in crime, and in action of secret services. In case that WMD are employed, X-ray diagnostic will be used to evaluate the prognosis (triage) and the risk of infection.

  19. Explosive destruction of 26Al

    NASA Astrophysics Data System (ADS)

    Kahl, D.; Yamaguchi, H.; Shimizu, H.; Abe, K.; Beliuskina, O.; Cha, S. M.; Chae, K. Y.; Ge, Z.; Hayakawa, S.; Kwag, M. S.; Kim, D. H.; Moon, J. Y.; Park, S. Y.; Yang, L.

    2017-09-01

    The γ -ray emission associated with the radioactive decay of 26Al is one of the key pieces of observational evidence indicating stellar nucleosynthesis is an ongoing process in our Galaxy, and it was the first such radioactivity to be detected. Despite numerous efforts in stellar modeling, observation, nuclear theory, and nuclear experiment over the past four decades, the precise sites and origin of Galactic ^{26} Al remain elusive. We explore the present experimental knowledge concerning the destruction of ^{26} Al in massive stars. The precise stellar rates of neutron-induced reactions on ^{26} Al, such as (n,p) and (n, α , have among the largest impacts on the total ^{26} Al yield. Meanwhile, reactions involving the short-lived isomeric state of ^{26} Al such as radiative proton capture are highly-uncertain at present. Although we presented on-going experimental work from n_TOF at CERN with an ^{26} Al target, the present proceeding focuses only on the ^{26} Al isomeric radioactive beam production aspect and the first experimental results at CRIB.

  20. 9 CFR 51.6 - Destruction of animals; time limit for destruction of animals.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Destruction of animals; time limit for destruction of animals. 51.6 Section 51.6 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION... ANIMALS DESTROYED BECAUSE OF BRUCELLOSIS Indemnity for Cattle, Bison, and Swine § 51.6 Destruction of...

  1. 9 CFR 51.6 - Destruction of animals; time limit for destruction of animals.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Destruction of animals; time limit for destruction of animals. 51.6 Section 51.6 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION... ANIMALS DESTROYED BECAUSE OF BRUCELLOSIS Indemnity for Cattle, Bison, and Swine § 51.6 Destruction of...

  2. 9 CFR 51.6 - Destruction of animals; time limit for destruction of animals.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Destruction of animals; time limit for destruction of animals. 51.6 Section 51.6 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION... ANIMALS DESTROYED BECAUSE OF BRUCELLOSIS Indemnity for Cattle, Bison, and Swine § 51.6 Destruction of...

  3. 9 CFR 51.6 - Destruction of animals; time limit for destruction of animals.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Destruction of animals; time limit for destruction of animals. 51.6 Section 51.6 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION... ANIMALS DESTROYED BECAUSE OF BRUCELLOSIS Indemnity for Cattle, Bison, and Swine § 51.6 Destruction of...

  4. 9 CFR 51.6 - Destruction of animals; time limit for destruction of animals.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Destruction of animals; time limit for destruction of animals. 51.6 Section 51.6 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION... ANIMALS DESTROYED BECAUSE OF BRUCELLOSIS Indemnity for Cattle, Bison, and Swine § 51.6 Destruction of...

  5. 32 CFR 2001.47 - Destruction.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Destruction. 2001.47 Section 2001.47 National... ARCHIVES AND RECORDS ADMINISTRATION CLASSIFIED NATIONAL SECURITY INFORMATION Safeguarding § 2001.47... pulverizing. Agencies shall comply with the destruction equipment standard stated in § 2001.42(b) of...

  6. 32 CFR 2001.47 - Destruction.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Destruction. 2001.47 Section 2001.47 National... ARCHIVES AND RECORDS ADMINISTRATION CLASSIFIED NATIONAL SECURITY INFORMATION Safeguarding § 2001.47... pulverizing. Agencies shall comply with the destruction equipment standard stated in § 2001.42(b) of...

  7. 32 CFR 2001.47 - Destruction.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Destruction. 2001.47 Section 2001.47 National... ARCHIVES AND RECORDS ADMINISTRATION CLASSIFIED NATIONAL SECURITY INFORMATION Safeguarding § 2001.47... pulverizing. Agencies shall comply with the destruction equipment standard stated in § 2001.42(b) of...

  8. 32 CFR 2001.47 - Destruction.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Destruction. 2001.47 Section 2001.47 National... ARCHIVES AND RECORDS ADMINISTRATION CLASSIFIED NATIONAL SECURITY INFORMATION Safeguarding § 2001.47... pulverizing. Agencies shall comply with the destruction equipment standard stated in § 2001.42(b) of...

  9. 32 CFR 2001.47 - Destruction.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Destruction. 2001.47 Section 2001.47 National... ARCHIVES AND RECORDS ADMINISTRATION CLASSIFIED NATIONAL SECURITY INFORMATION Safeguarding § 2001.47... pulverizing. Agencies shall comply with the destruction equipment standard stated in § 2001.42(b) of...

  10. 27 CFR 20.222 - Destruction.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Destruction. 20.222 Section 20.222 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS DISTRIBUTION AND USE OF DENATURED ALCOHOL AND RUM Destruction §...

  11. 27 CFR 20.222 - Destruction.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Destruction. 20.222 Section 20.222 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL DISTRIBUTION AND USE OF DENATURED ALCOHOL AND RUM Destruction §...

  12. 27 CFR 19.617 - Destruction records.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Destruction records. 19.617 Section 19.617 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU....617 Destruction records. Each time that a proprietor voluntarily destroys spirits, denatured...

  13. 27 CFR 20.222 - Destruction.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Destruction. 20.222 Section 20.222 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS DISTRIBUTION AND USE OF DENATURED ALCOHOL AND RUM Destruction §...

  14. 5 CFR 1312.29 - Destruction.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Information § 1312.29 Destruction. The destruction of classified material will be accomplished under the.... Classified official record material will be processed to the Information Systems and Technology, Records.... Classified nonrecord material will be destroyed as soon as it becomes excess to the needs of the office....

  15. Self-Destructive Behavior in Women.

    ERIC Educational Resources Information Center

    Kessel, Greer; Chrisler, Joan C.

    Trichotillomania (hair-pulling) and delicate self-cutting are self-destructive behaviors which utilize the body as a vehicle for self-expression. Like anorexia and bulimia, these behaviors occur primarily in young women. This study compared groups of women college students who engage in these self-destructive behaviors with those who do not. It…

  16. 27 CFR 20.222 - Destruction.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Destruction. 20.222 Section 20.222 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS DISTRIBUTION AND USE OF DENATURED ALCOHOL AND RUM Destruction §...

  17. 27 CFR 20.222 - Destruction.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Destruction. 20.222 Section 20.222 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL DISTRIBUTION AND USE OF DENATURED ALCOHOL AND RUM Destruction §...

  18. Energetic materials destruction using molten salt

    SciTech Connect

    Upadhye, R.S.; Watkins, B.E.; Pruneda, C.O.; Brummond, W.A.

    1994-04-29

    The Lawrence Livermore National Laboratory in conjunction with the Energetic Materials Center is developing methods for the safe and environmentally sound destruction of explosives and propellants as a part of the Laboratory`s ancillary demilitarization mission. LLNL has built a small-scale unit to test the destruction of HE using the Molten Salt Destruction (MSD) Process. In addition to the high explosive HMX, destruction has been carried out on RDX, PETN, ammonium picrate, TNT, nitroguanadine, and TATB. Also destroyed was a liquid gun propellant comprising hydroxyammonium nitrate, triethanolammonium nitrate and water. In addition to these pure components, destruction has been carried out on a number of commonly used formulations, such as LX-10, LX-16, LX-17, and PBX-9404.

  19. A new restoration of the NFP20-East cross section and possible tectonic overpressure in the Penninic Adula Nappe (Central Alps)

    NASA Astrophysics Data System (ADS)

    Pleuger, J.; Podladchikov, Y.

    2012-04-01

    The Adula Nappe in the eastern Central Alps is one of the four units in the Alps from which ultrahigh-pressure rocks have been reported. Several very different models for its tectonic history have been published but none of these models is fully satisfactory. In the models of Schmid et al. (1996) and Engi et al. (2001), the main mechanism of exhumation is assumed to be extrusion. The extrusion models require top-to-the-hinterland, i.e. top-to-the-south faulting in the hanging wall of the exhuming nappe for which there is no evidence. Froitzheim et al. (2003) proposed a scenario with two different subduction zones, an internal one in which the South Penninic and Briançonnais domains were subducted, and an external one in which the North Penninc domain and the European margin, including the Adula nappe, were subducted. In this model, the exhumation of the Adula nappe results from the subduction of the overlying sub-Briançonnais and sub-South-Penninic mantle in the internal subduction zone. The Adula nappe would then have been exhumed from below into a top-to-the-north shear zone also affecting the overriding Briançonnais units. The main shortcoming of this model is that otherwise there is little evidence for two Alpine subduction zones. All the models cited above are based on the conversion of peak pressures obtained from geobarometry to depth by assuming lithostatic pressures. This results in a much greater burial depth of the Adula Nappe with respect to the surrounding units which poses major problems when trying to reconcile maximum burial depths of the Penninic nappes with their structural record. We performed a new restoration of the NFP20-East cross section (Schmid et al. 1996) without applying a lithostatic pressure-to-depth conversion but a purely geometrical restoration of deformation events in the Penninic nappe stack. The major constraints on these reconstructions are given by strain estimates for the major deformation phases in the units overlying the

  20. The relationship between attributional style and destructive responses to job dissatisfaction: an exploratory study of internal migrant workers in China

    PubMed Central

    Kwan, Siu-On; Wong, Fu-Keung Daniel

    2014-01-01

    This study examines the relationship between attributional style and destructive responses to job dissatisfaction among internal migrant workers in mainland China. Contrary to previous studies conducted in the West, we found that internality of bad events was negatively related to destructive responses to job dissatisfaction. Stability and globality were positively related to destructive responses to job dissatisfaction. We suggest that the concept of interdependent self-construal may explain the unique positive meaning of internality of bad events among Chinese migrant workers. The practical significance of the findings is discussed. PMID:25750811

  1. Rubidium dimer destruction by a diode laser

    SciTech Connect

    Ban, T.; Aumiler, D.; Pichler, G.

    2005-02-01

    We observed rubidium dimer destruction by excitation of rubidium vapor with diode laser light tuned across the Rb D{sub 2} resonance line in a 2400 GHz tuning interval. The destruction was measured for rubidium atom concentrations in the (1-9)x10{sup 16} cm{sup -3} range, pump beam power up to 43 mW, and with a 5 Torr of the helium buffer gas. We discuss the physical mechanisms involved and specify the molecular pathways which may effectively lead to the observed dimer destruction.

  2. Non-destructive identification of twisted light.

    PubMed

    Li, Pengyun; Wang, Bo; Song, Xinbing; Zhang, Xiangdong

    2016-04-01

    The non-destructive identification of the orbital angular momentum (OAM) is essential to various applications in the optical information processing. Here, we propose and demonstrate experimentally an efficient method to identify non-destructively the OAM by using a modified Mach-Zehnder interferometer. Our schemes are applicable not only to the case with integer charges, but also to optical vortices with noninteger charges. Our Letter presents the first experimental demonstration of the non-destructive identification of twisted light with integer or noninteger topological charges, which has potential applications in the OAM-based data transmission for optical communications.

  3. Current state of knowledge on the behavior of steel liners in concrete containments subjected to overpressurization loads

    SciTech Connect

    von Riesemann, W.A.; Parks, M.B.

    1993-11-01

    In the United States, concrete containment buildings for commercial nuclear power plants have steel liners that act as the intemal pressure boundary. The liner abuts the concrete, acting as the interior concrete form. The liner is attached to the concrete by either studs or by a continuous structural shape (such as a T-section or channel) that is either continuously or intermittently welded to the liner. Studs are commonly used in reinforced concrete containments, while prestressed containments utilize a structural element as the anchorage. The practice in some countries follows the US practice, while in other countries the containment does not have a steel liner. In this latter case, there is a true double containment, and the annular region between the two containments is vented. This paper will review the practice of design of the liner system prior to the consideration of severe accident loads (overpressurization loads beyond the design conditions).

  4. Distribution and generation of the overpressure system, Eastern Delaware Basin, Western Texas and Southern New Mexico: Discussion

    SciTech Connect

    Cox, D.L.

    1995-12-01

    Interest in the paper by Luo et al. (1994) on Delaware basin overpressure was probably as great among drilling and completion engineers as the geologic community because of the obvious implications on drilling mud and well tubular programs. However, there are some inaccuracies in the paper`s comments relating to drill-stem test (DST) interpretation, which Luo et al. used to predict formation pressures in the study area. Referring to figure 3 in the paper, the authors identify points a and e as initial and final hydrostatic pressures (IHP and FP, respectively). Luo et al. state, `...the IHP and FHP represent the true fluid pressure of the formation at the depth of the testing tool.` The IHP and FP values actually represent the pressure exerted by the column of mud of a given weight in the well bore at the depth of the gauge, rather than the true fluid pressure of the formation.

  5. TECHNOLOGIES FOR CFC/HALON DESTRUCTION

    EPA Science Inventory

    The report presents an overview of the current status of possible technologies used to destroy chlorofluorocarbons (CFCs) and halons chemicals implicated in the destruction of the stratospheric ozone layer. The Montreal Protocol an international treaty to control the production a...

  6. TECHNOLOGIES FOR CFC/HALON DESTRUCTION

    EPA Science Inventory

    The report presents an overview of the current status of possible technologies used to destroy chlorofluorocarbons (CFCs) and halons chemicals implicated in the destruction of the stratospheric ozone layer. The Montreal Protocol an international treaty to control the production a...

  7. 32 CFR 644.497 - Destruction.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Destruction. Disposal by the Corps of Engineers, as authorized in AR 405-90, does not contemplate expenditure... appropriate Army of Air Force command for disposal action under AR 405-90 or AFR 87-4 as appropriate. However...

  8. Detection of Secondary Phases in UNS S32760 Superduplex Stainless Steel by Destructive and Non-destructive Techniques

    NASA Astrophysics Data System (ADS)

    Argandona, G.; Biezma, M. V.; Berrueta, J. M.; Berlanga, C.; Ruiz, A.

    2016-12-01

    Duplex stainless steels (DSS), with a microstructure of an approximately equal mixture of ferrite ( α) and austenite ( γ) phases, are susceptible to the formation of undesirable phases if manufacturing processes are not carefully controlled. In particular, sigma phase (σ) is a Cr- and Mo-rich intermetallic phase, formed generally when DSS are by the temperature range from 600 to 900 °C, even for very short time periods. The precipitation of this phase induces detrimental effects in mechanical and corrosion resistance properties in the material, and even a low volume percentage of σ phase can significantly affect these properties. The current paper presents the effect of thermal treatments on UNS S32760 superduplex stainless steel seamless tubes, applied in order to promote the precipitation of different σ phase percentages in a ferrite/austenite microstructure. The detection and quantification of the σ phase using non-destructive ultrasounds testing has been one of the most relevant events of this study that contributes to improving the correlation of the results obtained using destructive and non-destructive techniques for the quantification of undesirable phases in superduplex seamless tubes during the manufacturing process.

  9. Benefiting from a trail of destruction.

    PubMed

    Pickersgill, Julie

    2013-09-01

    Data destruction and IT asset disposal are heavily regulated and complex areas, especially within the NHS, which is responsible for the safekeeping of extremely personal data on millions of UK citizens. In the light of escalating efforts by the Information Commissioner's Office (ICO) to ensure compliance with the Data Protection Act 1998, data destruction specialist, Julie Pickersgill, of Advanced Digital Dynamics, outlines the requirements on estates departments for the secure disposal of IT equipment - and how to avoid falling foul of the law.

  10. A Novel Chemical Nitrate Destruction Process

    SciTech Connect

    Dziewinski, J.; Marczak, S.

    1999-03-01

    Nitrates represent one of the most significant pollutant discharged to the Baltic Sea by the Sliiamae hydrometallurgical plant. This article contains a brief overview of the existing nitrate destruction technologies followed by the description of a new process developed by the authors. The new chemical process for nitrate destruction is cost effective and simple to operate. It converts the nitrate to nitrogen gas which goes to the atmosphere.

  11. Prediction of Eggshell Ultrastructure via Some Non-destructive and Destructive Measurements in Fayoumi Breed

    PubMed Central

    Radwan, Lamiaa M.; Galal, A.; Shemeis, A. R.

    2015-01-01

    Possibilities of predicting eggshell ultrastructure from direct non-destructive and destructive measurements were examined using 120 Fayoumi eggs collected from the flock at 45 weeks of age. The non-destructive measurements included weight, length and width of the egg. The destructive measurements were breaking strength and shell thickness. The eggshell ultrastructure traits involved the total thickness of eggshell layer, thickness of palisade layer, cone layer and total score. Prediction of total thickness of eggshell layer based on non-destructive measurements individually or simultaneously was not possible (R2 = 0.01 to 0.16). The destructive measurements were far more accurate than the non-destructive in predicting total thickness of eggshell layer. Prediction based on breaking strength alone was more accurate (R2 = 0.85) than that based on shell thickness alone (R2 = 0.72). Adding shell thickness to breaking strength (the best predictor) increased the accuracy of prediction by 5%. The results obtained indicated that both non-destructive and destructive measurements were not useful in predicting the cone layer (R2 not exceeded 18%). The maximum accuracy of prediction of total score (R2 = 0.48) was obtained from prediction based on breaking strength alone. Combining shell thicknesses and breaking strength into one equation was no help in improving the accuracy of prediction. PMID:26104404

  12. Prediction of Eggshell Ultrastructure via Some Non-destructive and Destructive Measurements in Fayoumi Breed.

    PubMed

    Radwan, Lamiaa M; Galal, A; Shemeis, A R

    2015-07-01

    Possibilities of predicting eggshell ultrastructure from direct non-destructive and destructive measurements were examined using 120 Fayoumi eggs collected from the flock at 45 weeks of age. The non-destructive measurements included weight, length and width of the egg. The destructive measurements were breaking strength and shell thickness. The eggshell ultrastructure traits involved the total thickness of eggshell layer, thickness of palisade layer, cone layer and total score. Prediction of total thickness of eggshell layer based on non-destructive measurements individually or simultaneously was not possible (R(2) = 0.01 to 0.16). The destructive measurements were far more accurate than the non-destructive in predicting total thickness of eggshell layer. Prediction based on breaking strength alone was more accurate (R(2) = 0.85) than that based on shell thickness alone (R(2) = 0.72). Adding shell thickness to breaking strength (the best predictor) increased the accuracy of prediction by 5%. The results obtained indicated that both non-destructive and destructive measurements were not useful in predicting the cone layer (R(2) not exceeded 18%). The maximum accuracy of prediction of total score (R(2) = 0.48) was obtained from prediction based on breaking strength alone. Combining shell thicknesses and breaking strength into one equation was no help in improving the accuracy of prediction.

  13. Empirical confirmation of creative destruction from world trade data.

    PubMed

    Klimek, Peter; Hausmann, Ricardo; Thurner, Stefan

    2012-01-01

    We show that world trade network datasets contain empirical evidence that the dynamics of innovation in the world economy indeed follows the concept of creative destruction, as proposed by J.A. Schumpeter more than half a century ago. National economies can be viewed as complex, evolving systems, driven by a stream of appearance and disappearance of goods and services. Products appear in bursts of creative cascades. We find that products systematically tend to co-appear, and that product appearances lead to massive disappearance events of existing products in the following years. The opposite-disappearances followed by periods of appearances-is not observed. This is an empirical validation of the dominance of cascading competitive replacement events on the scale of national economies, i.e., creative destruction. We find a tendency that more complex products drive out less complex ones, i.e., progress has a direction. Finally we show that the growth trajectory of a country's product output diversity can be understood by a recently proposed evolutionary model of Schumpeterian economic dynamics.

  14. Empirical Confirmation of Creative Destruction from World Trade Data

    PubMed Central

    Klimek, Peter; Hausmann, Ricardo; Thurner, Stefan

    2012-01-01

    We show that world trade network datasets contain empirical evidence that the dynamics of innovation in the world economy indeed follows the concept of creative destruction, as proposed by J.A. Schumpeter more than half a century ago. National economies can be viewed as complex, evolving systems, driven by a stream of appearance and disappearance of goods and services. Products appear in bursts of creative cascades. We find that products systematically tend to co-appear, and that product appearances lead to massive disappearance events of existing products in the following years. The opposite–disappearances followed by periods of appearances–is not observed. This is an empirical validation of the dominance of cascading competitive replacement events on the scale of national economies, i.e., creative destruction. We find a tendency that more complex products drive out less complex ones, i.e., progress has a direction. Finally we show that the growth trajectory of a country’s product output diversity can be understood by a recently proposed evolutionary model of Schumpeterian economic dynamics. PMID:22719989

  15. Matching Analysis of Socially Appropriate and Destructive Behavior in Developmental Disabilities

    ERIC Educational Resources Information Center

    Hoch, John; Symons, Frank J.

    2007-01-01

    This study examined socially appropriate and destructive behavior in unconstrained natural environments using a matching law analysis (MLA) of real time observational data. The participants were two school-age children and one adult with mild to moderate cognitive disabilities. Event lagged sequential analysis (SQA) provided the obtained rates of…

  16. Can we infer the magma overpressure threshold before an eruption? Insights from ground deformation time series and numerical modeling of reservoir failure.

    NASA Astrophysics Data System (ADS)

    Albino, F.; Gregg, P. M.; Amelug, F.

    2015-12-01

    Overpressure within a magma chamber is a key parameter to understanding the onset of an eruption. Recent investigations indicate that surface inflation at a volcanic edifice does not always precede eruption (Chaussard and Amelung, 2012; Biggs et al., 2014), suggesting that the overpressure threshold may differ between volcanoes. To understand the failure conditions of a magma reservoir, mechanical models were developed to quantify the range of overpressure affordable in a reservoir for a given situation. Even if the choice of the failure criterion is still debated, most investigators agree that the overpressure required to fail the magma reservoir is at first order a function of the crustal stress field and the shape of the magma reservoir. Radar interferometry (InSAR) provides a large dataset of ground deformation worldwide, but many of these InSAR studies continue to use point or dislocation sources (Mogi, Okada) to explain deformation on volcanoes. Even if these simple solutions often fit the data and estimate the depth and the volume change of the source of deformation, key parameters such as the magma overpressure or the mechanical properties of the rocks cannot be derived. We use mechanical numerical models of reservoir failure combined with ground deformation data. It has been observed that volume change before an eruption can easily range one or two order of magnitude from 1-100x106 m3. The first goal of this study is to understand which parameter(s) control the critical volume changes just before the failure of the reservoir. First, a parametric study is performed to quantify the effect of the geometry of the reservoir (radius, depth), the local stress (compressive/extensive) and even the crust rheology (elastic/viscoelastic). We then compare modeling results with several active volcanoes where long time series of volume change are available: Okmok and Westdahl in Alaska, Sinabung and Agung in Indonesia and Galapagos. For each case, the maximum

  17. Evolution of pore-fluid pressure during folding and basin contraction in overpressured reservoirs assessed by combined fracture analysis and calcite twinning paleopiezometry

    NASA Astrophysics Data System (ADS)

    Beaudoin, Nicolas; Lacombe, Olivier; Bellahsen, Nicolas; Amrouch, Khalid; Daniel, Jean-Marc

    2014-05-01

    Reconstructing the evolution of paleofluid (over)pressure in sedimentary basins during deformation is a challenging problem, especially when no hydrocarbon-bearing fluid inclusions are available to provide barometric constraints on the fluid system. This contribution reports the application to a natural case (the Bighorn Basin) of recent methodological advance to access fluid (over)pressure level prevailing in strata during sub-seismic fracture development. The fluid pressure evolution in the Mississippian-Permian Madison-Phosphoria carbonate reservoir is tentatively reconstructed from the early Sevier Layer Parallel Shortening to the Laramide folding in two basement-cored folds: the Sheep Mountain Anticline and the Rattlesnake Mountain Anticline, located on both edges of the Bighorn Basin. This reconstruction is based on a combination of stress inversion of fault slip data, calcite twins paleopiezometry and rock mechanics. Results point out that supra-hydrostatic pressure values prevail in the carbonate reservoir during most of its whole Sevier-Laramide history, and a coeval evolution between fluid overpressure and differential stress build-up is also emphasized. In each fold, a maximum value of 30-35 MPa for overpressure (i.e. above hydrostatic value) is recorded, just before Laramide folding, while minimum values of 0 MPa or 7 MPa are recorded during Sevier foreland flexure/forebulge and Laramide folding, respectively. After normalization to the same depth for both folds of differential stress magnitudes obtained from calcite twins paleopiezometry, the reconstructed values for the two folds can be compared and this comparison provides an image of the evolution fluid pressure levels at the basin scale. Until folding, the evolution of the fluid overpressure during deformation can be interpreted as reflecting large-scale fluid migrations in a laterally connected reservoir. The drop of fluid overpressure recorded in both folds during folding illustrates the

  18. Entropic destruction of a moving heavy quarkonium

    NASA Astrophysics Data System (ADS)

    Fadafan, Kazem Bitaghsir; Tabatabaei, Seyed Kamal

    2016-07-01

    Recently it has been shown that the peak of the quarkonium entropy at the deconfinement transition is related to the emergent entropic force which destructs the quarkonium. Using the AdS/CFT correspondence, we consider dissociation of a moving heavy quarkonium by entropic force. For larger distance of quark and antiquark, the entropy of moving quarkonium increases, monotonically. We find that the entropic force destructs the moving quarkonium easier than the static case. By considering the Maxwell charge, we study the effect of the medium on the destruction of heavy quarkonium. It is shown that the quarkonium dissociates easier in the medium. Our results imply that the quarkonium dissociates easier when it moves orthogonal to the plasma wind rather than parallel.

  19. [Comparative toxicity of photosensitizers in varying destruction].

    PubMed

    Sinitsina, O O; Zholdakova, Z I; Poliakova, E E; Golovach, E N; Sycheva, L P; Beliaeva, N N; Kuznetsova, N A

    2007-01-01

    The toxicity of the photosensitizers proflavine acetate (PA) versus methylene blue (MB) was evaluated during their varying destruction. Under the influence of visible light, a partial (25%) transformation of the photosensitizers was shown to be attended by their enhanced toxicity and 100% destruction of the parent substances caused a reduction in their hazard. PA and its phototransformation products mainly affect the antiperoxide protection system and the structural and functional states of the liver, kidney, and duodenum. The maximum noneffective dose is 0.002 mg/kg. The possibility of using PA for water disinfection depends on the ratio of safe and effective concentrations. A partial (25%) MB destruction products cause mutagenic effects; the permissible dose of the mutagen is 0.00025 mg/kg. MB is not recommended for disinfection of all types of waters.

  20. Creative Destruction and Subjective Well-Being.

    PubMed

    Aghion, Philippe; Akcigit, Ufuk; Deaton, Angus; Roulet, Alexandra

    2016-12-01

    In this paper we analyze the relationship between turnover-driven growth and subjective wellbeing. Our model of innovation-led growth and unemployment predicts that: (i) the effect of creative destruction on expected individual welfare should be unambiguously positive if we control for unemployment, less so if we do not; (ii) job creation has a positive and job destruction has a negative impact on wellbeing; (iii) job destruction has a less negative impact in US Metropolitan Statistical Areas (MSA) within states with more generous unemployment insurance policies; (iv) job creation has a more positive effect on individuals that are more forward-looking. The empirical analysis using cross-sectional MSA-level and individual-level data provide empirical support to these predictions.

  1. Non-Destructive State Machine Reverse Engineering

    SciTech Connect

    Smith, Jessica L.

    2013-10-10

    Most of the integrated circuits (ICs) that are in electronic systems today are based on state machines. We are taking advantage of this to develop a hardware reverse engineering method that discovers the IC’s underlying state machine, rather than its transistors and gates. While there are other methods for destructively reverse engineering ICs or for non-destructively characterizing ICs, our method offers a fast and accurate analysis while remaining non-destructive. To do this, we present an intelligent brute-force method of exploring the logic of the IC using only the input and outputs designed into the IC - the I/O pins. From this exploration, we can apply a folding algorithm to discover the designed state machine.

  2. Influence of fluid overpressure on sliding with or without frontal buttress. Insights from analytical and experimental modeling

    NASA Astrophysics Data System (ADS)

    Lacoste, A.; Vendeville, B.; Mourgues, R.; Loncke, L.

    2009-12-01

    Hydrocarbon cracking can generate gases that migrate upward and may be trapped beneath low-permeability strata. The resulting fluid overpressure reduces shear strength, allowing gravitational sliding of the overlying cover. The driving force is the slope-parallel component of the weight of the cover, whereas the resisting forces are the friction at the base of the cover and the buttressing resistance to shortening downslope. Typically, a slide is bounded by normal faults upslope and thrusts downslope. But, sometimes, the slide is bounded downslope by a creek incision, and no compressional structures are found. We show how these two types of slides markedly differ in terms of mechanics, geometry, and kinematics using both analytical and experimental models. Mourgues et al. (2009) proposed an analytical model for gravity sliding of a laterally continuous sedimentary pile overlying an overpressured horizon. There, sliding can occur only if the driving force can overcome the buttressing resistance downslope, i.e., if the slide has a minimum required length, which depends on the thickness and rheological properties of the cover, and fluid pressure. The predicted length of the slide decreases with increasing pore pressure and decreasing cover thickness (Fig.1A). We ran the same calculation for a set up in which the base of the slope is incised, hence there is no downslope buttress. Unlike the first set up, the sliding sheet length increases with increasing fluid pressure (Fig.1B). We also tested the influence of varying slope angles, cover thicknesses and permeabilities of the décollement layer. The fluid pressure required to trigger sliding decreases where the basal slope and the cover thickness increase. Changes in décollement permeability have only a minor influence. We undertook a series of analogue experiments to check the evolution predicted by the analytical models. Fluids were simulated by compressed air applied at the base of models made of sand and low

  3. Matrix metalloproteinases in destructive lung disease.

    PubMed

    Houghton, A McGarry

    2015-01-01

    Matrix metalloproteinases (MMPs) play essential physiologic roles in numerous processes ranging from development to wound repair. Unfortunately, given the broad substrate specificity of the MMP family as a whole, aberrant degradation of extracellular matrix proteins can result in destructive disease. Emphysema, the result of destroyed lung elastin and collagen matrix, is the prototypical example of such a destructive process. More recent data has highlighted that MMPs play much more elaborate physiologic and pathophysiologic roles than simple matrix protein cleavage. Key pathophysiological roles for MMPs in emphysema will be discussed herein.

  4. Test of Thermal Transport Models through Dynamic Overpressure Stabilization of Ablation-Front Perturbation Growth in Laser-Driven CH Foils

    SciTech Connect

    Gotchev, O.V.; Goncharov, V.N.; Knauer, J.P.; Boehly, T.R.; Collins, T.J.B.; Epstein, R.; Jaanimagi, P.A.; Meyerhofer, D.D.

    2006-03-24

    Heat-flow-induced dynamic overpressure at the perturbed ablation front of an inertial confinement fusion target can stabilize the ablative Richtmyer-Meshkov-like instability and mitigate the subsequent ablative Rayleigh-Taylor (RT) instability. A series of experiments was performed on the OMEGA laser to quantify the dynamic overpressure stabilization during the shock transit. Analysis of the experimental data using hydrocode simulations shows that the observed oscillatory evolution of the ablation-front perturbations depends on D{sub c}, the size of the thermal conduction zone, and the fluid velocity in the blowoff region V{sub bl} that are sensitive to the thermal transport model used. We show that the simulations match the experiment well when the time dependence of the heat-flux inhibition is taken into account using a recently developed nonlocal heat-transport model [V. N. Goncharov et al., Phys. Plasmas 13, 012702 (2006)].

  5. Test of Thermal Transport Models through Dynamic Overpressure Stabilization of Ablation-Front Perturbation Growth in Laser-Driven CH Foils

    SciTech Connect

    Gotchev, O.V.; Goncharov, V.N.; Knauer, J.P.; Boehly, T.R.; Collins, T.J.B.; Epstein, R.; Jaanimagi, P.A.; Meyerhofer, D.D.

    2006-03-24

    Heat-flow-induced dynamic overpressure at the perturbed ablation front of an ICF target can stabilize the ablative Richtmyer/Meshkov-like instability and mitigate the subsequent ablative Rayleigh/Taylor (RT) instability. A series of experiments was performed on the OMEGA laser to quantify the dynamic overpressure stabilization during the shock transit. Analysis of the experimental data using hydrocode simulations shows that the observed oscillatory evolution of the ablation-front perturbations depends on Dc, the size of the thermal conduction zone, and the fluid velocity in the blowoff region Vbl that are sensitive to the thermal transport model used. We show that the simulations match the experiment well when the time dependence of the heat-flux inhibition is taken into account using a recently developed nonlocal heat transport model.

  6. Test of thermal transport models through dynamic overpressure stabilization of ablation-front perturbation growth in laser-driven CH foils.

    PubMed

    Gotchev, O V; Goncharov, V N; Knauer, J P; Boehly, T R; Collins, T J B; Epstein, R; Jaanimagi, P A; Meyerhofer, D D

    2006-03-24

    Heat-flow-induced dynamic overpressure at the perturbed ablation front of an inertial confinement fusion target can stabilize the ablative Richtmyer-Meshkov-like instability and mitigate the subsequent ablative Rayleigh-Taylor (RT) instability. A series of experiments was performed on the OMEGA laser to quantify the dynamic overpressure stabilization during the shock transit. Analysis of the experimental data using hydrocode simulations shows that the observed oscillatory evolution of the ablation-front perturbations depends on Dc, the size of the thermal conduction zone, and the fluid velocity in the blowoff region Vb1 that are sensitive to the thermal transport model used. We show that the simulations match the experiment well when the time dependence of the heat-flux inhibition is taken into account using a recently developed nonlocal heat-transport model [V. N. Goncharov et al., Phys. Plasmas 13, 012702 (2006)].

  7. Overpressure blast-wave induced brain injury elevates oxidative stress in the hypothalamus and catecholamine biosynthesis in the rat adrenal medulla.

    PubMed

    Tümer, Nihal; Svetlov, Stanislav; Whidden, Melissa; Kirichenko, Nataliya; Prima, Victor; Erdos, Benedek; Sherman, Alexandra; Kobeissy, Firas; Yezierski, Robert; Scarpace, Philip J; Vierck, Charles; Wang, Kevin K W

    2013-06-07

    Explosive overpressure brain injury (OBI) impacts the lives of both military and civilian population. We hypothesize that a single exposure to OBI results in increased hypothalamic expression of oxidative stress and activation of the sympatho-adrenal medullary axis. Since a key component of blast-induced organ injury is the primary overpressure wave, we assessed selective biochemical markers of autonomic function and oxidative stress in male Sprague Dawley rats subjected to head-directed overpressure insult. Rats were subjected to single head-directed OBI with a 358kPa peak overpressure at the target. Control rats were exposed to just noise signal being placed at ~2m distance from the shock tube nozzle. Sympathetic nervous system activation of the adrenal medullae (AM) was evaluated at 6h following blast injury by assessing the expression of catecholamine biosynthesizing enzymes, tyrosine hydroxylase (TH), dopamine-β hydroxylase (DβH), neuropeptide Y (NPY) along with plasma norepinephrine (NE). TH, DβH and NPY expression increased 20%, 25%, and 91% respectively, following OBI (P<0.05). Plasma NE was also significantly elevated by 23% (P<0.05) following OBI. OBI significantly elevated TH (49%, P<0.05) in the nucleus tractus solitarius (NTS) of the brain stem while AT1 receptor expression and NADPH oxidase activity, a marker of oxidative stress, was elevated in the hypothalamus following OBI. Collectively, the increased levels of TH, DβH and NPY expression in the rat AM, elevated TH in NTS along with increased plasma NE suggest that single OBI exposure results in increased sympathoexcitation. The mechanism may involve the elevated AT1 receptor expression and NADPH oxidase levels in the hypothalamus. Taken together, such effects may be important factors contributing to pathology of brain injury and autonomic dysfunction associated with the clinical profile of patients following OBI. Published by Elsevier Ireland Ltd.

  8. Response of Basic Structural Elements and B-52 Structural Components to Simulated Nuclear Overpressure. Volume I-Program Description and Results (Basic Structural Elements)

    DTIC Science & Technology

    1979-09-30

    overpressure pulse, were generated by ignit- iog PETN primacord and composition 4 explosive charges. The explosive was positioned in the centerline of the...L r- r-t(HONIfS NH3 I-O NI ) NI~flhJS 107 0( V)- 1 T-4 < > ui CY) < r C)- uj (D 0 ~u J4I C)i C)C CDD LOO0C 1i ( HN /MN-OO IU 1081 TABLE 11 STATIC LOAD

  9. The use of loop-seals for the control of the overpressures in hydraulic transients evolving in a sea service water system

    NASA Astrophysics Data System (ADS)

    Canetta, D.; Capozza, A.; Iovino, G.

    The transient response following pump trip-offs and start-ups was investigated in the sea water system of a nuclear power plant. Specific care was devoted to water column separation and cavity collapse phenomena. A computer program designed for analysis of complex hydraulic networks was used. It is found that dangerous overpressures can be avoided by the use of loop seals. The design of the vacuum breaker valves of the loop seals and the optimization of overall transient behavior is discussed.

  10. Black Swan Event Assessment for Fort Leonard Wood, Missouri

    DTIC Science & Technology

    2016-03-01

    training days. ............................................ 40 Figure 27. Projected ecosystem shifts...Table 6. Missouri precipitation extremes. (Source: Missouri Climate Center.) .................... 24 Table 7. Richter scale destruction level...probable to cause a negative impact on the installation. Examples of threat agents are destructive natural events, disaffected employees

  11. Effects of Exposure to Blast Overpressure on Intracranial Pressure and Blood-Brain Barrier Permeability in a Rat Model.

    PubMed

    Kawoos, Usmah; Gu, Ming; Lankasky, Jason; McCarron, Richard M; Chavko, Mikulas

    2016-01-01

    Exposure to blast overpressure (BOP) activates a cascade of pathological processes including changes in intracranial pressure (ICP) and blood-brain barrier (BBB) permeability resulting in traumatic brain injury (TBI). In this study the effect of single and multiple exposures at two intensities of BOP on changes in ICP and BBB permeability in Sprague-Dawley rats was evaluated. Animals were exposed to a single or three repetitive (separated by 0.5 h) BOPs at 72 kPa or 110 kPa. ICP was monitored continuously via telemetry for 6 days after exposure to BOP. The alteration in the permeability of BBB was determined by extravasation of Evans Blue (EB) into brain parenchyma. A significant increase in ICP was observed in all groups except the single 72 kPa BOP group. At the same time a marked increase in BBB permeability was also seen in various parts of the brain. The extent of ICP increase as well as BBB permeability change was dependent on intensity and frequency of blast.

  12. Effects of Exposure to Blast Overpressure on Intracranial Pressure and Blood-Brain Barrier Permeability in a Rat Model

    PubMed Central

    Kawoos, Usmah; Gu, Ming; Lankasky, Jason; McCarron, Richard M.; Chavko, Mikulas

    2016-01-01

    Exposure to blast overpressure (BOP) activates a cascade of pathological processes including changes in intracranial pressure (ICP) and blood-brain barrier (BBB) permeability resulting in traumatic brain injury (TBI). In this study the effect of single and multiple exposures at two intensities of BOP on changes in ICP and BBB permeability in Sprague-Dawley rats was evaluated. Animals were exposed to a single or three repetitive (separated by 0.5 h) BOPs at 72 kPa or 110 kPa. ICP was monitored continuously via telemetry for 6 days after exposure to BOP. The alteration in the permeability of BBB was determined by extravasation of Evans Blue (EB) into brain parenchyma. A significant increase in ICP was observed in all groups except the single 72 kPa BOP group. At the same time a marked increase in BBB permeability was also seen in various parts of the brain. The extent of ICP increase as well as BBB permeability change was dependent on intensity and frequency of blast. PMID:27907158

  13. Operation Hardtack. Project 3. 2. Response of earth-confined flexible-arch structures in high-overpressure regions

    SciTech Connect

    LeDoux, J.C.; Rush, P.J.

    1985-09-01

    The purpose of this project was to determine structural responses and failure criteria of earth-confined corrugated-steel flexible arches subjected to high overpressure blast loading from nuclear detonations. A flexible arch is considered as an arch structure whose ultimate supporting capacity is dependent upon confinement within a surrounding earth configuration. A collateral objective was to determine the radiation-shielding effectiveness of such structures with a minimum cover of five feet of coral sand. Because the soil and ground-water conditions at Eniwetok did not permit the placing of the steel arches below natural-grade level, the structures were confined within massive non-drag sensitive earthwork configurations of coral sand. Empirical determinations were made of the responses of (1) three earth-confined prefabricated corrugated-steel flexible arches when subjected to relatively long-duration blast loadings from a megaton range detonation; and (2) one similar earth-confined flexible-arch when subjected to relatively short-duration blast loadings from a kiloton-range detonation.

  14. Possible mechanism of horizontal overpressure generation of the Khibiny, Lovozero, and Kovdor ore clusters on the Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Rebetsky, Yu. L.; Sim, L. A.; Kozyrev, A. A.

    2017-07-01

    The paper discusses questions related to the generation of increasing crustal horizontal compressive stresses compared to the idea of the standard gravitational state at the elastic stage or even from the prevalence of horizontal compression over vertical stress equal to the lithostatic pressure. We consider a variant of superfluous horizontal compression related to internal lithospheric processes occurrin in the crust of orogens, shields, and plates. The vertical ascending movements caused by these motions at the sole of the crust or the lithosphere pertain to these and the concomitant exogenic processes giving rise to denudation and, in particular, to erosion of the surfaces of forming rises. The residual stresses of the gravitational stressed state at the upper crust of the Kola Peninsula have been estimated for the first time. These calculations are based on the volume of sediments that have been deposited in Arctic seas beginning from the Mesozoic. The data speak to the possible level of residual horizontal compressive stresses up to 90 MPa in near-surface crustal units. This estimate is consistent with the results of in situ measurements that have been carried out at the Mining Institute of the Kola Science Center, Russian Academy of Sciences (RAS), for over 40 years. It is possible to forecast the horizontal stress gradient based on depth using our concept on the genesis of horizontal overpressure, and this forecasting is important for studying the formation of endogenic deposits.

  15. Method for non-destructive testing

    DOEpatents

    Akers, Douglas W [Idaho Falls, ID

    2011-08-30

    Non-destructive testing method may include providing a source material that emits positrons in response to bombardment of the source material with photons. The source material is exposed to photons. The source material is positioned adjacent the specimen, the specimen being exposed to at least some of the positrons emitted by the source material. Annihilation gamma rays emitted by the specimen are detected.

  16. 27 CFR 40.253 - Destruction.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Destruction. 40.253 Section 40.253 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY (CONTINUED) TOBACCO MANUFACTURE OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES,...

  17. Destruction of dirty ice mantles by sputtering

    NASA Technical Reports Server (NTRS)

    Aannestad, P. A.

    1973-01-01

    Dirty ice mantles are destroyed efficiently by sputtering of He atoms when clouds encounter shock velocities greater than 13-15 km/sec. Destruction due to grain-grain collisions is found to be about .001 times less efficient. Sputtering in the hot intercloud medium should make intercloud grains smaller than cloud grains.

  18. Home destruction within the Hayman Fire perimeter

    Treesearch

    Jack Cohen; Rick Stratton

    2003-01-01

    The Hayman Fire report on home destruction examines the following four questions: 1. How many homes were destroyed out of the total number of homes within the Hayman Fire perimeter? 2. What was the relative wildland fire intensity associated with the destroyed homes? 3. What was the categorical cause of home ignition suggested by the associated wildland fire intensity...

  19. Development and analysis of a leak-based blast attenuator and scaling laws for primary blast peak overpressure for a large caliber muzzleloaded cannon

    NASA Astrophysics Data System (ADS)

    Carson, Robert Andrew

    One of the primary aspects of the research and development work carried out at Benet Laboratories is the Soldier. Maintenance of their health in the field is the first priority while the second priority is the enhancement of their performance. Therefore, a new concept for a weapon system that targets these two priorities is highly desirable. This is the case with a new concept that can reduce the peak overpressure without the use of a muzzle device for a muzzle loaded cannon system. Such a novel concept was developed in this thesis through the application of propellant leak into the precursor region, i.e., when the projectile is still in the bore. A 3D hydrocode (ALE3D) was employed to predict the blast overpressure for the baseline and propellant leak configurations. However, a 3D hydrocode is computationally very expensive to predict peak overpressure in the far-field and an efficient method to predict peak overpressure in the far-field is of significance. Therefore, scaling laws for primary blast peak overpressure were also developed in this thesis. Initially, two propellant leak concepts were examined. A bulge leak method and a channel leak method, which were compared to the baseline configuration. The initial channel leak configuration (referred to as CLM-1) significantly reduced the exit pressure ratio during projectile ejection, and thereby, resulted in a weaker blast. This in-turn substantially attenuated the peak overpressure to the rear of the muzzle without the aid of a muzzle device while having a marginal loss in the projectile exit velocity. For CLM-1, at one monitored location with the largest peak overpressure, a reduction of about 38% in peak overpressure was observed as compared to the baseline case. In order to compare different leak configurations, a performance metric was defined by comparing the ratio of peak overpressure and projectile exit velocity for a leak configuration to that for the baseline configuration. This metric was referred to

  20. Analysis of ex-vessel debris/water interaction and a potential overpressurization of containment

    SciTech Connect

    Yang, J.W.

    1980-01-01

    In the event of a meltdown in a PWR in which the disrupted core materials breach the primary vessel, the hot debris will interact with water in the containment cavity. The debris-water interaction provides a rapid generation of steam, which could build up pressure beyond the containment building limit. Previous analysis of the debris-water interactions was based on the single-sphere model, in which the internal and surface heat transfer are the control mechanism. In this study, the debris-water interaction is analyzed in terms of a porous debris bed model. The debris cooling and steam generation are controlled by the hydrodynamics of the two-phase flow. Different porous models developed by Dhir-Catton and Lipinski were examined and used to test their impact on containment dynamics. The results show that the magnitude of the predicted pressure rises is not affected by the different models. The occurence of the peak pressure, however, is considerably delayed by using the porous bed model.

  1. Destructive and Non-Destructive Analysis Techniques for Failure Detection of QFN Packages

    NASA Astrophysics Data System (ADS)

    Adhila, M. N.; Wedianti, S.; Suhaimi, W. S. W. M.; Aishah, I.

    2010-03-01

    One of the latest developments in packaging technology is the QFN (Quad Flat Non-Lead) packages, which is both a chip scale package and plastic encapsulated package with lead pad at the bottom. In this paper, different type of commercial QFN single die packages were characterized by using destructive and non-destructive techniques. Non-destructive techniques such as Scanning Acoustic Microscope (SAM) and X-Ray analysis were used to observe package cracking, delamination and other failure mode. Application of SAM include detection of delaminations between lead frame, die face, paddle, heat sink, cracks and plastic encapsulant. In comparison to other techniques, SAM is sensitive to detect beneath the surface of devices which would be inaccessible otherwise by both conventional optical and electron microscopy inspection methods. Destructive technique such as Field Emission Electron Microscopy (FESEM) was implemented to address the failures of the QFN single die packages such as die cracking, lifted ball bonds and other failure mode.

  2. Archaeological evidence for a destructive earthquake in Patras, Greece

    NASA Astrophysics Data System (ADS)

    Stiros, S. C.; Pytharouli, S. I.

    2014-07-01

    Oriented collapse of columns, large-scale destruction debris and temporary abandonment of the area deduced from an archaeological excavation provide evidence for a major (intensity IX) earthquake in Patras, Greece. This, and possibly a cluster of other earthquakes, can be derived from archaeological data. These earthquakes are not included in the historical seismicity catalogues, but can be used to put constraints to the seismic risk of this city. Patras was affected by a cluster of poorly documented earthquakes between 1714 and 1806. The city seems to be exposed to risks of progressive reactivation of a major strike-slip fault. A magnitude 6.4 earthquake in 2008 has been related to it. This fault has also been associated with a total of four events in the last 20 years, a situation reminiscent of the seismic hazard at the western edge of the North Anatolian Fault.

  3. Hybrid holographic non-destructive test system

    NASA Technical Reports Server (NTRS)

    Kurtz, R. L. (Inventor)

    1978-01-01

    An automatic hybrid holographic non-destructive testing (HNDT) method and system capable of detecting flaws or debonds contained within certain materials are described. This system incorporates the techniques of optical holography, acoustical/optical holography and holographic correlation in determining the structural integrity of a test object. An automatic processing system including a detector and automatic data processor is used in conjunction with the three holographic techniques for correlating and interpreting the information supplied by the non-destructive systems. The automatic system also includes a sensor which directly translates an optical data format produced by the holographic techniques into electrical signals and then transmits this information to a digital computer for indicating the structural properties of the test object. The computer interprets the data gathered and determines whether further testing is necessary as well as the format of this new testing procedure.

  4. Radiation-thermal destruction of cellulose

    SciTech Connect

    Ershov, B.G.; Samuilova, S.D.; Petropavlovskii, G.A.; Vasil'eva, G.G.

    1984-01-01

    A method of reducing the degree of polymerization of cellulose is explored. The cellulose is irradiated with gamma radiation from a /sup 60/Co source. The temperature is controlled between 303-433/sup 0/K. The temperature dependence of the depolymerization is described graphically. The radiation destruction of cellulose is accompanied by the formation of carboxyl and carbonyl groups. The carbonyl concentration is considerably higher than carboxyl at all temperatures. The concentrations of these groups increases with increasing temperature.

  5. Molten salt destruction of base hydrolysate

    SciTech Connect

    Watkins, B.E.; Kanna, R.L.; Chambers, R.D.; Upadhye, R.S.; Promeda, C.O.

    1996-10-01

    There is a great need for alternatives to open burn/open detonation of explosives and propellants from dismantled munitions. LANL has investigated the use of base hydrolysis for the demilitarization of explosives. Hydrolysates of Comp B, Octol, Tritonal, and PBXN-109 were processed in the pilot molten salt unit (in building 191). NOx and CO emissions were found to be low, except for CO from PBXN-109 processing. This report describes experimental results of the destruction of the base hydrolysates.

  6. Freon destruction in a nanosecond corona discharge

    SciTech Connect

    Akhmedzhanov, R.A.; Vikharev, A.L.; Gorbachev, A.M.

    1995-12-31

    One of the main reasons for destruction of the ozone layer is high content of freon in the Earth atmosphere. The life time of chlorofluorocarbons (CFC) in the stratosphere is tens of years, therefore, along with abandonment of the use of CFC compositions. of importance is the search for efficient ways to purify both industrial gaseous wastes and the atmosphere proper from pollution. Among various purification methods the most promising seems to be the method based on freon destruction during processes of dissociative electron attachment. Freon molecules in this case are destroyed selectively mainly at the stage of plasma decay by cold electrons, for which the constant of dissociative attachment is especially high (k{sub a} = 10{sup -7} - 10{sup -9}cm{sup 3}/s). By that, as the source of electrons we propose using nanosecond discharges with a high level of the reduced electric field, E/N, when the main share of the pulse energy goes into ionization, and gas heating is insignificant. These requirements are best met by the use of barrier and pulse corona discharge, which are widely employed for ozone generation and purification of gaseous wastes. Plasma of such discharges is composed of chaotically arising nanosecond microdischarges. The possibility to purify atmosphere from freons directly by means of a nanosecond microwave discharge produced the troposphere by ground-based sources is also studied. An important problem for the said applications, along with estimation of efficiency of freon destruction is determination of chemical composition of the products that appear at the post-discharge stage as the result of plasma chemical reaction. This presentation gives results of experimental studies of freon destruction in a pulse-periodic nanosecond corona discharge.

  7. Technologies Underlying Weapons of Mass Destruction

    DTIC Science & Technology

    1993-12-01

    Safeguards and the Civilian Nuclear Fuel Cycle 181 Appendix 4-D: Dual -Use Export Controls 191 5 The Proliferation of Delivery Systems summary 198...to which ‘‘ dual -use’ technologies or products—those also having legitimate applications-are involved in the devel- opment of weapons of mass...destruction is important, since both the feasibility of controlling dual -use items and the implications of doing so depend on the extent of their other

  8. Non-Destructive Evaluation of Aerospace Composites

    DTIC Science & Technology

    2009-03-01

    Master of Science in Materials Science Jeremy D. Johnson, BS Captain, USAF March 2009 APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED...non-destructive material evaluation (NDE) were used to inspect various forms of damage commonly found in aerospace fiberglass composites: voids...ultrasound, and flash IR thermography were analyzed for the detection of defects. Test results and analysis of each NDE method’s capabilities

  9. Emergency Destruction of Information Storing Media

    DTIC Science & Technology

    1987-12-01

    Section G HEAT and INCINERATION APPENDIX H- DESTRUCT TECHNOLOGY COMlPENDIM Section A SHREDDERS Section B PULVERIZERS Section C HAMMERMILLS Section D...Mechanical mutilation devices that are based on cutting can be grouped into three cate- gories: shredders, rotary knife mills, and hammermills . The...by the rotating blades and passed through the cutting stage again. c. Hammermiils A hammermill is a device that destroys material by pounding it

  10. Microfractures due to overpressures caused by thermal cracking in well-sealed upper Devonian reservoirs, deep Alberta basin

    SciTech Connect

    Marquez, X.M.; Mountjoy, E.W.

    1996-04-01

    Microfractures (<1 mm in width) filled with reservoir bitumen occur and crosscut all sedimentary and diagenetic phases in the upper 200 m of the partially to completely dolomitized Upper Devonian (Leduc Formation) Strachan buildup and other buildups in the deep Alberta basin. They display three patterns: (1) subhorizontal, extending from intraskeletal pores and subvertical fractures, (2) radial around vugs and molds, and (3) random in the matrix. Subhorizontal microfracturing is the most common, and radial is the least common. Overpressuring by thermal cracking of crude oil to gas during burial can produce most of the characteristics exhibited by these microfractures: their association with all pore types, bitumen fillings, and relatively late diagenetic timing. Microfractures are restricted to isolated buildups below depths of about 3800 m in the Alberta basin. The lack of microfractures in adjacent gas-bearing and updip buildups along the Rimbey-Meadowbrook reef trend is likely because of the connection of these buildups to a regional conduit system in the underlying Cooking Lake platform, preventing them from developing sufficient pressures. Thermal cracking of crude oil to gas during burial is also indicated by finely and coarsely deformed lamellar textures of the reservoir bitumen that fills the microfractures in the Strachan buildup. This thermal cracking took place during the Late Cretaceous when the buildup was buried deeper than about 3500 m; however, tectonic compression occurred immediately west of these areas during the Late Cretaceous and early Tertiary Laramide orogeny, modifying the stress field. Suprahydrostatic (abnormal) pressures generated during thermal cracking of oil in conjunction with Laramide tectonic compression probably created the microfractures in isolated and effectively scaled reservoirs.

  11. Primary blast causes mild, moderate, severe and lethal TBI with increasing blast overpressures: Experimental rat injury model

    NASA Astrophysics Data System (ADS)

    Mishra, Vikas; Skotak, Maciej; Schuetz, Heather; Heller, Abi; Haorah, James; Chandra, Namas

    2016-06-01

    Injury severity in blast induced Traumatic Brain Injury (bTBI) increases with blast overpressure (BOP) and impulse in dose-dependent manner. Pure primary blast waves were simulated in compressed gas shock-tubes in discrete increments. Present work demonstrates 24 hour survival of rats in 0–450 kPa (0–800 Pa•s impulse) range at 10 discrete levels (60, 100, 130, 160, 190, 230, 250, 290, 350 and 420 kPa) and determines the mortality rate as a non-linear function of BOP. Using logistic regression model, predicted mortality rate (PMR) function was calculated, and used to establish TBI severities. We determined a BOP of 145 kPa as upper mild TBI threshold (5% PMR). Also we determined 146–220 kPa and 221–290 kPa levels as moderate and severe TBI based on 35%, and 70% PMR, respectively, while BOP above 290 kPa is lethal. Since there are no standards for animal bTBI injury severity, these thresholds need further refinements using histopathology, immunohistochemistry and behavior. Further, we specifically investigated mild TBI range (0–145 kPa) using physiological (heart rate), pathological (lung injury), immuno-histochemical (oxidative/nitrosative and blood-brain barrier markers) as well as blood borne biomarkers. With these additional data, we conclude that mild bTBI occurs in rats when the BOP is in the range of 85–145 kPa.

  12. Primary blast causes mild, moderate, severe and lethal TBI with increasing blast overpressures: Experimental rat injury model

    PubMed Central

    Mishra, Vikas; Skotak, Maciej; Schuetz, Heather; Heller, Abi; Haorah, James; Chandra, Namas

    2016-01-01

    Injury severity in blast induced Traumatic Brain Injury (bTBI) increases with blast overpressure (BOP) and impulse in dose-dependent manner. Pure primary blast waves were simulated in compressed gas shock-tubes in discrete increments. Present work demonstrates 24 hour survival of rats in 0–450 kPa (0–800 Pa∙s impulse) range at 10 discrete levels (60, 100, 130, 160, 190, 230, 250, 290, 350 and 420 kPa) and determines the mortality rate as a non-linear function of BOP. Using logistic regression model, predicted mortality rate (PMR) function was calculated, and used to establish TBI severities. We determined a BOP of 145 kPa as upper mild TBI threshold (5% PMR). Also we determined 146–220 kPa and 221–290 kPa levels as moderate and severe TBI based on 35%, and 70% PMR, respectively, while BOP above 290 kPa is lethal. Since there are no standards for animal bTBI injury severity, these thresholds need further refinements using histopathology, immunohistochemistry and behavior. Further, we specifically investigated mild TBI range (0–145 kPa) using physiological (heart rate), pathological (lung injury), immuno-histochemical (oxidative/nitrosative and blood-brain barrier markers) as well as blood borne biomarkers. With these additional data, we conclude that mild bTBI occurs in rats when the BOP is in the range of 85–145 kPa. PMID:27270403

  13. Performance of an over-pressure processed Bi-2223/Ag/SUS tape and a small layer-winding coil

    NASA Astrophysics Data System (ADS)

    Kitaguchi, Hitoshi; Takahashi, Ken-ichiro; Kumakura, Hiroaki; Hayashi, Toshihiro; Fujino, Kousou; Ayai, Naoki; Sato, Ken-ichi

    2009-04-01

    We have successfully demonstrated the utility and potential of Bi-2223/Ag tapes fabricated by a CT-OP (controlled-overpressure) process. In this paper, we report the Ic-B-T performance of a short tape with stainless steel lamination and energizing-test results of a small layer-winding coil in an external magnetic field ranging from 0 to 12 T and at temperatures ranging from 4.2 to 90 K. The coil is a solenoid layer-winding of a 135 m piece of Bi-2223/Ag tape with stainless steel lamination on both sides. The dimensions of the conductor are 2.7 mm in width and 0.25 mm in thickness, including a 0.02 mm thick stainless steel lamination on both sides. A short sample cut from the same tape has critical currents exceeding 76 A, 307 A and 438 A at 77 K, 30 K and 4.2 K, respectively, in self-field. The winding was performed using a 'react & wind' technique and the resultant coil had 597 turns and dimensions of 65 mm (inner diameter), 83 mm (outer diameter) and 60 mm (winding height). In 12 T, 4.2 K, the coil-Ic is 191 A, which adds 1.42 T to the external field. In the present coil, the coil-Ic is controlled by the field component in the coil's radial direction generated by the coil itself. The Ic values of the coil agree very well with those estimated from the short sample's performance and field distribution. The results indicate that the homogeneity of the Bi-2223 conductor is very good throughout its whole 135 m length.

  14. Neuro-glial and systemic mechanisms of pathological responses in rat models of primary blast overpressure compared to "composite" blast.

    PubMed

    Svetlov, Stanislav I; Prima, Victor; Glushakova, Olena; Svetlov, Artem; Kirk, Daniel R; Gutierrez, Hector; Serebruany, Victor L; Curley, Kenneth C; Wang, Kevin K W; Hayes, Ronald L

    2012-01-01

    A number of experimental models of blast brain injury have been implemented in rodents and larger animals. However, the variety of blast sources and the complexity of blast wave biophysics have made data on injury mechanisms and biomarkers difficult to analyze and compare. Recently, we showed the importance of rat position toward blast generated by an external shock tube. In this study, we further characterized blast producing moderate traumatic brain injury and defined "composite" blast and primary blast exposure set-ups. Schlieren optics visualized interaction between the head and a shock wave generated by external shock tube, revealing strong head acceleration upon positioning the rat on-axis with the shock tube (composite blast), but negligible skull movement upon peak overpressure exposure off-axis (primary blast). Brain injury signatures of a primary blast hitting the frontal head were assessed and compared to damage produced by composite blast. Low to negligible levels of neurodegeneration were found following primary blast compared to composite blast by silver staining. However, persistent gliosis in hippocampus and accumulation of GFAP/CNPase in circulation was detected after both primary and composite blast. Also, markers of vascular/endothelial inflammation integrin alpha/beta, soluble intercellular adhesion molecule-1, and L-selectin along with neurotrophic factor nerve growth factor-beta were increased in serum within 6 h post-blasts and persisted for 7 days thereafter. In contrast, systemic IL-1, IL-10, fractalkine, neuroendocrine peptide Orexin A, and VEGF receptor Neuropilin-2 (NRP-2) were raised predominantly after primary blast exposure. In conclusion, biomarkers of major pathological pathways were elevated at all blast set-ups. The most significant and persistent changes in neuro-glial markers were found after composite blast, while primary blast instigated prominent systemic cytokine/chemokine, Orexin A, and Neuropilin-2 release

  15. 9 CFR 51.25 - Proof of destruction.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Indemnity for Sheep, Goats, and Horses § 51.25 Proof of destruction. The Veterinarian in Charge will accept... accredited veterinarian attesting to the destruction of the animals; (d) A written, sworn statement by the...

  16. 7 CFR 160.9 - Destructively distilled wood turpentine.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Destructively distilled wood turpentine. 160.9 Section... REGULATIONS AND STANDARDS FOR NAVAL STORES General § 160.9 Destructively distilled wood turpentine. The designation “destructively distilled wood turpentine” shall refer to the kind of spirits of...

  17. 7 CFR 160.9 - Destructively distilled wood turpentine.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Destructively distilled wood turpentine. 160.9 Section... REGULATIONS AND STANDARDS FOR NAVAL STORES General § 160.9 Destructively distilled wood turpentine. The designation “destructively distilled wood turpentine” shall refer to the kind of spirits of...

  18. 7 CFR 160.9 - Destructively distilled wood turpentine.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Destructively distilled wood turpentine. 160.9 Section... REGULATIONS AND STANDARDS FOR NAVAL STORES General § 160.9 Destructively distilled wood turpentine. The designation “destructively distilled wood turpentine” shall refer to the kind of spirits of...

  19. Facing towards or Turning away from Destructive Narcissism

    ERIC Educational Resources Information Center

    Flynn, Denis; Skogstad, Helga

    2006-01-01

    This paper presents a detailed theoretical discussion of destructive narcissism in relation to Freud and Rosenfeld and later theorists. In destructive narcissism, the destructiveness is itself idealised and overrides "the vital functions which serve the purpose of self-preservation" (Freud, S., 1914, "On narcissism" S.E. 14: 87)--a feature which…

  20. Facing towards or Turning away from Destructive Narcissism

    ERIC Educational Resources Information Center

    Flynn, Denis; Skogstad, Helga

    2006-01-01

    This paper presents a detailed theoretical discussion of destructive narcissism in relation to Freud and Rosenfeld and later theorists. In destructive narcissism, the destructiveness is itself idealised and overrides "the vital functions which serve the purpose of self-preservation" (Freud, S., 1914, "On narcissism" S.E. 14: 87)--a feature which…

  1. 7 CFR 160.9 - Destructively distilled wood turpentine.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Destructively distilled wood turpentine. 160.9 Section... REGULATIONS AND STANDARDS FOR NAVAL STORES General § 160.9 Destructively distilled wood turpentine. The designation “destructively distilled wood turpentine” shall refer to the kind of spirits of turpentine...

  2. 7 CFR 160.9 - Destructively distilled wood turpentine.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Destructively distilled wood turpentine. 160.9 Section... REGULATIONS AND STANDARDS FOR NAVAL STORES General § 160.9 Destructively distilled wood turpentine. The designation “destructively distilled wood turpentine” shall refer to the kind of spirits of turpentine...

  3. Non-destructive evaluation of containment walls in nuclear power plants

    NASA Astrophysics Data System (ADS)

    Garnier, V.; Payan, C.; Lott, M.; Ranaivomanana, N.; Balayssac, J. P.; Verdier, J.; Larose, E.; Zhang, Y.; Saliba, J.; Boniface, A.; Sbartai, Z. M.; Piwakowski, B.; Ciccarone, C.; Hafid, H.; Henault, J. M.; Buffet, F. Ouvrier

    2017-02-01

    Two functions are regularly tested on containment walls in order to anticipate a possible accident. The first is mechanical to resist a possible internal over-pressure and the second is to prevent leakage. The AAPR reference accident is the rupture of a pipe in the primary circuit of a nuclear plant. In this case, the pressure and temperature can reach 5 bar and 180°C in 20 seconds. The national project `Non-destructive testing of the containment structures of nuclear plants' aims at studying the non-destructive techniques capable to evaluate the concrete properties and its damaging and cracks. This 4-year-project is segmented into two parts. The first consists in developing and selecting the most relevant NDEs in the laboratory to reach these goals. These evaluations are developed in conditions representing the real conditions of the stresses generated during ten-yearly visits of the plants or those related to an accident. The second part consists in applying the selected techniques to two containment structures under pressure. The first structure is proposed by ONERA and the second is a mockup of a containment wall on a 1/3 scale made by EDF within the VeRCoRs project. Communication is focused on the part of the project that concerns the damage and crack process characterization by means of NDT. The tests are done in 3 or 4 points bending in order to study the cracks' generation, their propagation, as well as their opening and closing. The main ultrasonic techniques developed concern linear or non-linear acoustic: acoustic emission [1], Locadiff [2], energy diffusion, surface wave's velocity and attenuation, DAET [3]. The recorded data contribute to providing the mapping of the investigated parameters, either in volume, in surface or globally. Digital image correlation is an important additional asset to validate the coherence of the data. The spatial normalization of the data in the specimen space allows proposing algorithms on the combination of the

  4. PANDA—A novel instrument for non-destructive sample analysis

    NASA Astrophysics Data System (ADS)

    Turunen, Jani; Peräjärvi, Kari; Pöllänen, Roy; Toivonen, Harri

    2010-01-01

    An instrument known as PANDA (Particles And Non-Destructive Analysis) for non-destructive sample analysis has been designed and built at the Finnish Radiation and Nuclear Safety Authority (STUK). In PANDA the measurement techniques and instruments designed for the basic research are applied to the analysis of environmental samples. PANDA has two vacuum chambers, one for loading samples and the other for measurements. In the measurement chamber there are two individual measurement positions. Currently the first one hosts an HPGe gamma detector and a position-sensitive alpha detector. The second measurement position is intended for precise characterization of found particles. PANDA's data are recorded in event mode and events are timestamped. In the present article the technical design of PANDA is presented in detail. In addition, its performance using depleted uranium particles and an air filter is demonstrated.

  5. Petroleum potential and over-pressuring in the molassic deposits of the south-eastern part of the South Adriatic Basin

    SciTech Connect

    Gjoka, M.; Dulaj, A.

    1995-08-01

    The southeastern portion of the South Adriatic basin extends onshore in Albania and is filled with a sequence of interbedded clays, sandstones and siltstones of Cenozoic age accumulated under turbiditic, slope, shelf, deltaic and, rarely, continental depositional conditions. Geochemical data suggest a fairly uniform vertical and lateral distribution of organic matter, with TOC values ranging from 0.1 to 0.4 wt%. Average organic matter content is 0.28 wt%. Kerogen is predominantly gas-prone, Type IIIa (Huminite-Inertinite) and IIIb (Inertinite-Huminite), and is thermally immature to marginally mature, even at depths of 6000 m. Vitrinite reflectance (Ro) values range from 0.3 to 0.5; the average geothermal gradient of the region is about 16{degrees}C/100 m. Three main gas zones can be recognized in the Pliocene to Middle Miocene (Serravallian) sequence: (1) a biogenic gas zone at depths of 1200-1500 m; (2) a mixed biogenic-thermogenic zone between 1500 and 4500-W m, and, (3) a thermogenic gas zone below 4500-5000 m. Gas is indigenous and has migrated into the sandstone reservoirs from adjacent shales (syngenetic) or deeper sources (syngenetic-long migration). Gas fields discovered to date are associated with crestal culminations and with the eastern flank of structures. The normal hydrostatic gradient for the Neogene sediments is 0.437 Psi/ft, but overpressures have been encountered in numerous wells and are considered a regional phenomenon. The top of the overpressures crosses stratigraphic boundaries. The gradient is gradual and seem to increase in sequences with sandstone content of 15 to 20%. Steep pressure gradients are found on flanks and plunges of structures. Overpressuring is attributed to the very high sedimentation rate (760 m per million year) during the Neogene and resulting undercompacted shales.

  6. The use of HANDIDET{reg_sign} non-electric detonator assemblies to reduce blast-induced overpressure at AECL`s Underground Research Laboratory

    SciTech Connect

    Onagi, D.P.; Keith, S.G.; Kuzyk, G.W.; Proudfoot, D.F.

    1996-12-01

    A number of aspects of the Canadian concept for nuclear fuel waste disposal are being assessed by Atomic Energy of Canada Limited (AECL) in a series of experiments at its Underground Research Laboratory (URL) near Lac du Bonnet, Manitoba, Canada. One of the major objectives of the work being carried out at the URL is to develop and evaluate the methods and technology to ensure safe, permanent disposal of Canada`s nuclear fuel waste. In 1994, AECL excavated access tunnels and a laboratory room for the Quarried Block Fracture Migration Experiment (QBFME) at the 240 Level of the URL. This facility will be used to study the transport of radionuclides in natural fractures in quarried blocks of granite under in-situ groundwater conditions. The experiment is being carried out under a cooperative agreement with the Japan Atomic Energy Research Institute. The excavation of the QBFME access tunnels and laboratory was carried out using controlled blasting techniques that minimized blast-induced overpressure which could have damaged or interrupted other ongoing experiments in the vicinity. The majority of the blasts used conventional long delay non-electric detonators but a number of blasts were carried out using HANDIDET 250/6000 non-electric long delay detonator assemblies and HTD{reg_sign} non-electric short delay trunkline detonator assemblies. The tunnel and laboratory excavation was monitored to determine the levels of blast-induced overpressure. This paper describes the blasting and monitoring results of the blasts using HANDIDET non-electric detonator assemblies and the effectiveness of these detonators in reducing blast-induced overpressure.

  7. Destruction of Refractory Carbon in Protoplanetary Disks

    NASA Astrophysics Data System (ADS)

    Anderson, Dana E.; Bergin, Edwin A.; Blake, Geoffrey A.; Ciesla, Fred J.; Visser, Ruud; Lee, Jeong-Eun

    2017-08-01

    The Earth and other rocky bodies in the inner solar system contain significantly less carbon than the primordial materials that seeded their formation. These carbon-poor objects include the parent bodies of primitive meteorites, suggesting that at least one process responsible for solid-phase carbon depletion was active prior to the early stages of planet formation. Potential mechanisms include the erosion of carbonaceous materials by photons or atomic oxygen in the surface layers of the protoplanetary disk. Under photochemically generated favorable conditions, these reactions can deplete the near-surface abundance of carbon grains and polycyclic aromatic hydrocarbons by several orders of magnitude on short timescales relative to the lifetime of the disk out to radii of ˜20-100+ au from the central star depending on the form of refractory carbon present. Due to the reliance of destruction mechanisms on a high influx of photons, the extent of refractory carbon depletion is quite sensitive to the disk’s internal radiation field. Dust transport within the disk is required to affect the composition of the midplane. In our current model of a passive, constant-α disk, where α = 0.01, carbon grains can be turbulently lofted into the destructive surface layers and depleted out to radii of ˜3-10 au for 0.1-1 μm grains. Smaller grains can be cleared out of the planet-forming region completely. Destruction may be more effective in an actively accreting disk or when considering individual grain trajectories in non-idealized disks.

  8. FIRST 100 T NON-DESTRUCTIVE MAGNET

    SciTech Connect

    J. R. SIMS; ET AL

    1999-10-01

    The first 100 T non-destructive (100 T ND) magnet and power supplies as currently designed are described. This magnet will be installed as part of the user facility research equipment at the National High Magnetic Field Laboratory (NHMFL) Pulsed Field Facility at Los Alamos National Laboratory. The 100 T ND magnet will provide a 100 T pulsed field of 5 ms duration (above 90% of full field) in a 15 mm diameter bore once per hour. Magnet operation will be non-destructive. The magnet will consist of a controlled power outer coil set which produces a 47 T platform field in a 225 mm diameter bore. Located within the outer coil set will be a 220 mm outer diameter capacitor powered insert coil. Using inertial energy storage a synchronous motor/generator will provide ac power to a set of seven ac-dc converters rated at 64 MW/80 MVA each. These converters will energize three independent coil circuits to create 170 MJ of field energy in the outer coil set at the platform field of 47 T. The insert will then be energized to produce the balance of the 100 T peak field using a 2.3 MJ, 18 kV (charged to 15 kV), 14.4 mF capacitor bank controlled with solid-state switches. The magnet will be the first of its kind and the first non-destructive, reusable 100 T pulsed magnet. The operation of the magnet will be described along with special features of its design and construction.

  9. Biologic and chemical weapons of mass destruction.

    PubMed

    Bozeman, William P; Dilbero, Deanna; Schauben, Jay L

    2002-11-01

    Weapons of mass destruction (WMDs) are capable of producing massive casualties and are typically grouped into nuclear, biologic, and chemical weapons. In the wake of the September 11th disasters, attention to terrorist groups and the potential for use of WMDs has increased. Biologic and chemical weapons are relatively accessible and inexpensive to develop, and are thought to be the most available to foreign states and subnational terrorist groups. This article reviews various biologic and chemical weapons, including emergency diagnosis and management of selected agents.

  10. Anode materials for electrochemical waste destruction

    NASA Technical Reports Server (NTRS)

    Molton, Peter M.; Clarke, Clayton

    1990-01-01

    Electrochemical Oxidation (ECO) offers promise as a low-temperature, atmospheric pressure method for safe destruction of hazardous organic chemical wastes in water. Anode materials tend to suffer corrosion in the intensely oxidizing environment of the ECO cell. There is a need for cheaper, more resistant materials. In this experiment, a system is described for testing anode materials, with examples of several common anodes such as stainless steel, graphite, and platinized titanium. The ECO system is simple and safe to operate and the experiment can easily be expanded in scope to study the effects of different solutions, temperatures, and organic materials.

  11. Solar power satellite system definition study. Part 2, volume 8: SPS launch vehicle ascent and entry sonic overpressure and noise effects

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Recoverable launch vehicle concepts for the Solar Power Satellite program were identified. These large launch vehicles are powered by proposed engines in the F-1 thrust level class. A description of the candidate launch vehicles and their operating mode was provided. Predictions of the sonic over pressures during ascent and entry for both types of vehicles, and prediction of launch noise levels in the vicinity of the launch site were included. An overall assessment and criteria for sonic overpressure and noise levels was examined.

  12. Effects of mild TBI from repeated blast overpressure on the expression and extinction of conditioned fear in rats.

    PubMed

    Genovese, R F; Simmons, L P; Ahlers, S T; Maudlin-Jeronimo, E; Dave, J R; Boutte, A M

    2013-12-19

    Mild traumatic brain injury (mTBI) and post-traumatic stress disorder (PTSD) are pressing medical issues for the Warfighter. Symptoms of mTBI can overlap with those of PTSD, suggesting the possibility of a causal or mediating role of mTBI in PTSD. To address whether mTBI can exacerbate the neurobiological processes associated with traumatic stress, we evaluated the impact of mTBI from a blast overpressure (BOP) on the expression of a conditioned fear. In the rat, conditioned fear models are used to evaluate the emotional conditioning processes that are known to become dysfunctional in PTSD. Rats were first trained on a variable interval (VI), food maintained, operant conditioning task that established a general measure of performance. Inescapable electric shock (IES) was paired with an audio-visual conditioned stimulus (CS) and followed 1day later by three daily exposures to BOP (75kPa). Subsequently, the CS alone was presented once every 7days for 2months, beginning 4days following the last BOP. The CS was presented during the VI sessions allowing a concurrent measure of performance. Treatment groups (n=10, each group) received IES+BOP, IES+sham-BOP, sham-IES+BOP or sham-IES+sham-BOP. As expected, pairing the CS with IES produced a robust conditioned fear that was quantified by a suppression of responding on the VI. BOP significantly decreased the expression of the conditioned fear. No systematic short- or long-term performance deficits were observed on the VI from BOP. These results show that mTBI from BOP can affect the expression of a conditioned fear and suggests that BOP caused a decrease in inhibitory behavioral control. Continued presentation of the CS produced progressively less response suppression in both fear conditioned treatments, consistent with extinction of the conditioned fear. Taken together, these results show that mTBI from BOP can affect the expression of a conditioned fear but not necessarily in a manner that increases the conditioned fear or

  13. Non-destructive diffraction enhanced imaging of seeds.

    PubMed

    Young, Lester W; Parham, Christopher; Zhong, Zhong; Chapman, Dean; Reaney, Martin J T

    2007-01-01

    Techniques that make possible the non-destructive continuous observation of plant anatomy and developmental processes provide novel insights into these phenomena. Non-destructive imaging of seeds was demonstrated using the synchrotron-based X-ray imaging technique, diffraction enhanced imaging (DEI). The seed images obtained had good contrast and definition, allowing anatomical structures and physiological events to be observed. Structures such as hypocotyl-root axes, cotyledons, seed coats, air cavities, and embryo-less Brassica napus L. seeds were readily observed using DEI. Embryo axes, scutella, pericarp furrows, coleoptiles, and roots were observable over a time-course in individual germinating Triticum aestivum L. caryopses. Novel anatomical and physiological observations were also made that would have been difficult to make continuously using other techniques. The physical principles behind DEI make it a unique imaging technique. Contrast in DEI is the result of X-ray refraction at the density differences occurring at tissue boundaries, scatter caused by regions containing ordered molecules such as cellulose fibres, and attenuation. Sectioning of samples and the infusion of stains or other contrast agents are not necessary. Furthermore, as high-energy X-rays are used (30-40 keV), little X-ray absorption occurs, resulting in low levels of radiation damage. Consequently, studies of developmental processes may be performed on individuals. Individual germinating B. napus and T. aestivum seeds were imaged at several time points without incurring any apparent radiation damage. DEI offers a unique way of examining plant anatomy, development, and physiology, and provides images that are complementary to those obtained through other techniques.

  14. Controlling weapons of mass destruction through the rule of law

    SciTech Connect

    Tanzman, E.A.

    1995-08-08

    Many who speak of the end of the Cold War emphasize the improvement in international relations when they speak of the momentous consequences of this event. According to this image, the half century since Trinity has been a period of sparse international communication during which the Eastern and Western blocs hibernated in their isolated dens of security alliances. The emphasis in the phrase ``Cold War`` was on the word ``cold,`` and relations with the former Communist regimes are now ``warm`` by comparison. It is equally valid to consider what has happened to the word ``was` in this highly descriptive phrase. While meaningful international dialogue was in a state of relative lethargy during much of the last fifty years, the military establishments of the Great Powers were actively engaged in using as much force as possible in their efforts to control world affairs, short of triggering a nuclear holocaust. Out of these military postures a tense peace ironically emerged, but the terms by which decisions were made about controlling weapons of mass destruction (i.e., nuclear, chemical, and biological weapons) were the terms of war. The thesis of this paper is that the end of the Cold War marks a shift away from reliance on military might toward an international commitment to controlling weapons,of mass destruction through the ``rule of law.`` Rawls wrote that ``legal system is a coercive order of public rules addressed to rational persons for the purpose of regulating their conduct and providing the framework for social cooperation. The regular and impartial administration of public rules, becomes the rule of law when applied to the legal system.`` Inparticular, Rawls identifies as part of this system of public rules those laws that aim to prevent free riders on the economic system and those that aim to correct such externalities as environmental pollution.``

  15. The Overpressured Student

    ERIC Educational Resources Information Center

    Weissbourd, Richard

    2011-01-01

    When it comes to academic achievement, many parents in upper- and middle-class communities have gone overboard, hiring tutors for their preschool children and going to enormous lengths to secure a spot for their child in a prestigious college. Even though poor children face many hardships, teenagers in affluent families suffer emotional and moral…

  16. Overpressure Contact Printing

    SciTech Connect

    Guo,Q.; Teng,X.; Yang,H.

    2004-09-15

    This paper describes a new method of using elastometric stamps in the fabrication of patterned self-assembled monolayers and nanoparticles. By applying load on top of poly(dimethylsiloxane) (PDMS) stamps, we showed that new structure arrays of various materials could be generated on silicon wafer and metal substrates through the controlled deformation of elastometric stamps. The feature sizes of the patterns generated by this technique have been shown to be up to an order of a magnitude smaller than those on the stamps. The created patterns also may not exist on the original masters; thus, this approah can be unique in making patterns at a reduced size that can sometimes be hard to fabricate otherwise.

  17. Blast Overpressure Studies.

    DTIC Science & Technology

    1998-05-01

    17. COSATI CODES FIELD GROUP SUB-GROUP 18. SUBJECTTERMS (Continue on reverse if necessary and identify by block number) impulse noise, hearing... block number) To satisfy the Army’s need for realistic safe limits for heavy weapons noise while wearing hearing protection, a 2-1/2 year study was...that Blocked the Hole in the Stem of the Plug IV-5 XI I. INTRODUCTION The objective of this study was to determine the safe limits of occupational

  18. The Overpressured Student

    ERIC Educational Resources Information Center

    Weissbourd, Richard

    2011-01-01

    When it comes to academic achievement, many parents in upper- and middle-class communities have gone overboard, hiring tutors for their preschool children and going to enormous lengths to secure a spot for their child in a prestigious college. Even though poor children face many hardships, teenagers in affluent families suffer emotional and moral…

  19. Longitudinal confocal microscopy imaging of solid tumor destruction following adoptive T cell transfer

    PubMed Central

    Schietinger, Andrea; Arina, Ainhoa; Liu, Rebecca B; Wells, Sam; Huang, Jianhua; Engels, Boris; Bindokas, Vytas; Bartkowiak, Todd; Lee, David; Herrmann, Andreas; Piston, David W; Pittet, Mikael J; Lin, P Charles; Zal, Tomasz; Schreiber, Hans

    2013-01-01

    A fluorescence-based, high-resolution imaging approach was used to visualize longitudinally the cellular events unfolding during T cell-mediated tumor destruction. The dynamic interplay of T cells, cancer cells, cancer antigen loss variants, and stromal cells—all color-coded in vivo—was analyzed in established, solid tumors that had developed behind windows implanted on the backs of mice. Events could be followed repeatedly within precisely the same tumor region—before, during and after adoptive T cell therapy—thereby enabling for the first time a longitudinal in vivo evaluation of protracted events, an analysis not possible with terminal imaging of surgically exposed tumors. T cell infiltration, stromal interactions, and vessel destruction, as well as the functional consequences thereof, including the elimination of cancer cells and cancer cell variants were studied. Minimal perivascular T cell infiltrates initiated vascular destruction inside the tumor mass eventually leading to macroscopic central tumor necrosis. Prolonged engagement of T cells with tumor antigen-crosspresenting stromal cells correlated with high IFNγ cytokine release and bystander elimination of antigen-negative cancer cells. The high-resolution, longitudinal, in vivo imaging approach described here will help to further a better mechanistic understanding of tumor eradication by T cells and other anti-cancer therapies. PMID:24482750

  20. EFFLUENT TREATMENT FACILITY PEROXIDE DESTRUCTION CATALYST TESTING

    SciTech Connect

    HALGREN DL

    2008-07-30

    The 200 Area Effluent Treatment Facility (ETF) main treatment train includes the peroxide destruction module (PDM) where the hydrogen peroxide residual from the upstream ultraviolet light/hydrogen peroxide oxidation unit is destroyed. Removal of the residual peroxide is necessary to protect downstream membranes from the strong oxidizer. The main component of the PDM is two reaction vessels utilizing granular activated carbon (GAC) as the reaction media. The PDM experienced a number of operability problems, including frequent plugging, and has not been utilized since the ETF changed to groundwater as the predominant feed. The unit seemed to be underperforming in regards to peroxide removal during the early periods of operation as well. It is anticipated that a functional PDM will be required for wastewater from the vitrification plant and other future streams. An alternate media or methodology needs to be identified to replace the GAC in the PDMs. This series of bench scale tests is to develop information to support an engineering study on the options for replacement of the existing GAC method for peroxide destruction at the ETF. A number of different catalysts will be compared as well as other potential methods such as strong reducing agents. The testing should lead to general conclusions on the viability of different catalysts and identify candidates for further study and evaluation.

  1. Non-Inflammatory Destructive Periodontal Disease

    PubMed Central

    José Ricardo Kina; Yumi Umeda Suzuki, Thaís; Fumico Umeda Kina, Eunice; Kina, Juliana; Kina, Mônica

    2016-01-01

    Background: Non-Inflammatory Destructive Periodontal Disease (NIDPD), is a severe destructive periodontal disease, that is characterized by the attachment loss and alveolar bone loss, without signs of the gingival inflammation, and the periodontal pocket development. Objective: Despite the fact that various cases of NIDPD have been reported; their etiology and disease evolution is still indefinite, and therefore, are open for discussion. Method: An NIDPD case was studied in order to demonstrate features of the disease, and discuss the possible etiology and treatment. Results: In this clinical case, the etiology of NIDPD seems to be an association of endogenous opportunist bacteria with anatomical aspects, occlusion pattern, emotional stress and mouth breathing condition. Conclusion: In spite of all cases described in the literature are comparable and may have similar etiology as related in this clinical case, additional research is needed to identify and clarify the role of the etiologic factors which determine the disease. PMID:27053968

  2. Brittle Destruction of Carbon Based Materials

    NASA Astrophysics Data System (ADS)

    Koza, Y.; Amouroux, S.; Bazylev, B. N.; Berthe, E.; Kuehnlein, W.; Linke, J.; Penkalla, H. J.; Singheiser, L.

    Erosion mechanisms for different carbon based materials (graphite, carbon fiber composites (CFCs), Si-doped CFC) have been studied under brittle destruction under intense transient thermal loads (ELMs, plasma disruptions, VDEs) with respect to material erosion in different particle emission regimes, characterization of emitted particles, and behavior of preheated samples. Furthermore, the experimental data were compared with 3-D numerical simulation on the onset of brittle destruction. From a morphological point of view, the resulting erosion patterns on the test samples and ejected particles differ significantly for the three materials. The isotropic graphite shows a homogeneous erosion profile with flat craters, while the CFC forms no crater and only preferential erosion in localized spots in the PAN fiber area while the pitch fiber strands remain almost undamaged. The particles originating from graphite samples which have been collected on TEM grids are composed of nano sized amorphous carbon. CFCs have been the source for sub Î 1/4 m sized agglomerated fragments of crystalline carbon or silicon particles with âe 1/4 50 nm diameter. Preheating of the test samples to 500 or 800°C results in a remarkable increase of the erosion depth and weight loss compared to the samples loaded at room temperature and identical heat fluxes. In particular, melting phenomena in the Si-doped CFC materials became essential at elevated temperatures.

  3. Complementary Electromagnetic Non-Destructive Evaluation

    NASA Astrophysics Data System (ADS)

    Tian, Gui Yun; Wilson, John; Morozov, Maxim

    2011-06-01

    The use of non-destructive evaluation (NDE) for defect detection and failure prediction in structures and specimens is widespread in energy industries, aimed at ageing power plants and pipelines, material degradation, fatigue and radiation damage, etc. At present there are no suitable electromagnetic NDE methods for the measurement and characterization of material degradation, in irradiated samples in particular, which is very important and timely for the nuclear power industry in the UK. This paper reports recent developments in the field of electromagnetic (EM) NDE at Newcastle University, including pulsed eddy current (PEC), pulsed magnetic flux leakage (PMFL), magnetic Barkhausen emission (MBE) and magneto-acoustic emission (MAE). As different EM methods have different strengths, an integrative EM framework is introduced. Case studies through the second round robin tests organized by the Universal Network for Magnetic Non-Destructive Evaluation (UNMNDE), representing eighteen leading research groups worldwide in the area of electromagnetic NDE, are reported. Twelve samples with different ageing times and rolling reduction ratios were tested using different magnetic methods among the UNMNDE members. Based on the studies, the complementary characteristics of electromagnetic techniques for NDE are discussed.

  4. Event Perception.

    PubMed

    Radvansky, Gabriel; Zacks, Jeffrey M

    2011-11-01

    Events are central elements of human experience. Formally, they can be individuated in terms of the entities that compose them, the features of those entities, and the relations amongst entities. Psychologically, representations of events capture their spatiotemporal location, the people and objects involved, and the relations between these elements. Here, we present an account of the nature of psychological representations of events and how they are constructed and updated. Event representations are like images in that they are isomorphic to the situations they represent. However, they are like models or language in that they are constructed of components rather than being holistic. Also, they are partial representations that leave out some elements and abstract others. Representations of individual events are informed by schematic knowledge about general classes of events. Event representations are constructed in a process that segments continuous activity into discrete events. The construction of a series of event representations forms a basis for predicting the future, planning for that future, and imagining alternatives.

  5. Event Perception

    PubMed Central

    Radvansky, Gabriel; Zacks, Jeffrey M.

    2012-01-01

    Events are central elements of human experience. Formally, they can be individuated in terms of the entities that compose them, the features of those entities, and the relations amongst entities. Psychologically, representations of events capture their spatiotemporal location, the people and objects involved, and the relations between these elements. Here, we present an account of the nature of psychological representations of events and how they are constructed and updated. Event representations are like images in that they are isomorphic to the situations they represent. However, they are like models or language in that they are constructed of components rather than being holistic. Also, they are partial representations that leave out some elements and abstract others. Representations of individual events are informed by schematic knowledge about general classes of events. Event representations are constructed in a process that segments continuous activity into discrete events. The construction of a series of event representations forms a basis for predicting the future, planning for that future, and imagining alternatives. PMID:23082236

  6. Eye-Directed Overpressure Airwave-Induced Trauma Causes Lasting Damage to the Anterior and Posterior Globe: A Model for Testing Cell-Based Therapies

    PubMed Central

    Bricker-Anthony, Courtney; Hines-Beard, Jessica

    2016-01-01

    Abstract Purpose: Characterization of the response of the Balb/c mouse to an eye-directed overpressure airwave, with the hypothesis that this mouse strain and model is useful for testing potential therapeutics for the treatment of traumatic eye injury. Methods: The left eyes of adult Balb/c mice were exposed to an eye-directed overpressure airwave. Intraocular pressure (IOP) was measured and eyes were inspected for gross pathology changes. Optical coherence tomography and histology were used to examine the structural integrity of the retina and optic nerve. Immunohistochemistry, in vivo molecular fluorophores, and a multiplex enzyme-linked immunosorbent assay were utilized to identify changes in cell death, neuroinflammation, and oxidative stress. Results: This model induced a transient increase in IOP, corneal injuries, infrequent large retinal detachments, retinal pigment epithelium (RPE) vacuolization, glial reactivity, and retinal cell death. Both the corneal damage and RPE vacuolization persisted with time. Optic nerve degeneration occurred as early as 7 days postinjury and persisted out to 60 days. Retinal cell death, increased levels of reactive oxygen species, and neuroinflammation were detected at 7 days postinjury. Conclusions: The injury profile of the Balb/c mouse is consistent with commonly observed pathologies in blast-exposed patients. The damage is throughout the eye and persistent, making this mouse model useful for testing cell-based therapies. PMID:26982447

  7. Eye-Directed Overpressure Airwave-Induced Trauma Causes Lasting Damage to the Anterior and Posterior Globe: A Model for Testing Cell-Based Therapies.

    PubMed

    Bricker-Anthony, Courtney; Hines-Beard, Jessica; Rex, Tonia S

    2016-06-01

    Characterization of the response of the Balb/c mouse to an eye-directed overpressure airwave, with the hypothesis that this mouse strain and model is useful for testing potential therapeutics for the treatment of traumatic eye injury. The left eyes of adult Balb/c mice were exposed to an eye-directed overpressure airwave. Intraocular pressure (IOP) was measured and eyes were inspected for gross pathology changes. Optical coherence tomography and histology were used to examine the structural integrity of the retina and optic nerve. Immunohistochemistry, in vivo molecular fluorophores, and a multiplex enzyme-linked immunosorbent assay were utilized to identify changes in cell death, neuroinflammation, and oxidative stress. This model induced a transient increase in IOP, corneal injuries, infrequent large retinal detachments, retinal pigment epithelium (RPE) vacuolization, glial reactivity, and retinal cell death. Both the corneal damage and RPE vacuolization persisted with time. Optic nerve degeneration occurred as early as 7 days postinjury and persisted out to 60 days. Retinal cell death, increased levels of reactive oxygen species, and neuroinflammation were detected at 7 days postinjury. The injury profile of the Balb/c mouse is consistent with commonly observed pathologies in blast-exposed patients. The damage is throughout the eye and persistent, making this mouse model useful for testing cell-based therapies.

  8. Sonic-boom measurements in the focus region during the ascent of Apollo 17. [maximum positive overpressure, positive impulse, signature duration, and bow-shock rise time

    NASA Technical Reports Server (NTRS)

    Henderson, H. R.; Hilton, D. A.

    1974-01-01

    Sonic-boom pressure signatures recorded during the ascent phase of Apollo 17 are presented. The measurements were obtained onboard six U.S. Navy ships positioned along the ground track of the spacecraft vehicle in the area of expected focus resulting from the flight path and acceleration of the vehicle. Tracings of the measured signatures are presented along with values of the maximum positive overpressure, positive impulse, signature duration, and bowshock rise time. Also included are brief descriptions of the ships and their location, the deployment of the sonic-boom instrumentation, flight profiles and operating conditions for the launch vehicle and spacecraft, surface-weather and sea-state information at the measuring sites, and high-altitude weather information for the general measurement areas. Comparisons of the measured and predicted sonic-boom overpressures for the Apollo 17 mission are presented. The measured data are also compared with data from the Apollo 15 and 16 missions and data from flight test programs of various aircraft.

  9. Hypergolic Propellant Destruction Evaluation Cost Benefit Analysis

    NASA Technical Reports Server (NTRS)

    Kessel, Kurt

    2010-01-01

    At space vehicle launch sites such as Vandenberg Air Force Base (VAFB), Cape Canaveral Air Force Station (CCAFS) and Kennedy Space Center (KSC), toxic vapors and hazardous liquid wastes result from the handling of commodities (hypergolic fuels and oxidizers), most notably from transfer operations where fuel and oxidizer are transferred from bulk storage tanks or transfer tankers to space launch vehicles. During commodity transfer at CCAFS and KSC, wet chemical scrubbers (typically containing four scrubbing towers) are used to neutralize fuel saturated vapors from vent systems on tanks and tanker trailers. For fuel vapors, a citric acid solution is used to scrub out most of the hydrazine. Operation of both the hypergolic fuel and oxidizer vapor scrubbers generates waste scrubber liquor. Currently, scrubber liquor from the fuel vapor scrubber is considered non-hazardous. The scrubber liquor is defined as spent citric acid scrubber solution; the solution contains complexed hydrazine I methylhydrazine and is used to neutralize nonspecification hypergolic fuel generated by CCAFS and KSC. This project is a collaborative effort between Air Force Space Command (AFSPC), Space and Missile Center (SMC), the CCAFS, and National Aeronautics and Space Administration (NASA) to evaluate microwave destruction technology for the treatment of non-specification hypergolic fuel generated at CCAFS and KSC. The project will capitalize on knowledge gained from microwave treatment work being accomplished by AFSPC and SMC at V AFB. This report focuses on the costs associated with the current non-specification hypergolic fuel neutralization process (Section 2.0) as well as the estimated costs of operating a mobile microwave unit to treat non-specification hypergolic fuel (Section 3.0), and compares the costs for each (Section 4.0).The purpose of this document is to assess the costs associated with waste hypergolic fuel. This document will report the costs associated with the current fuel

  10. Mechanical study of the Chartreuse Fold-and-Thrust Belt: relationships between fluids overpressure and decollement within the Toarcian source-rock

    NASA Astrophysics Data System (ADS)

    Berthelon, Josselin; Sassi, William; Burov, Evgueni

    2016-04-01

    Many source-rocks are shale and constitute potential detachment levels in Fold-and-Thrust Belts (FTB): the toarcian Schistes-Cartons in the French Chartreuse FTB for example. Their mechanical properties can change during their burial and thermal maturation, as for example when large amount of hydrocarbon fluids are generated. A structural reconstruction of the Chartreuse FTB geo-history places the Toarcian Formation as the major decollement horizon. In this work, a mechanical analysis integrating the fluids overpressuring development is proposed to discuss on the validity of the structural interpretation. At first, an analogue of the Chartreuse Toarcian Fm, the albanian Posidonia Schist, is documented as it can provide insights on its initial properties and composition of its kerogen content. Laboratory characterisation documents the vertical evolution of the mineralogical, geochemical and mechanical parameters of this potential decollement layer. These physical parameters (i.e. Total Organic Carbon (TOC), porosity/permeability relationship, friction coefficient) are used to address overpressure buildup in the frontal part of the Chartreuse FTB with TEMISFlow Arctem Basin modelling approach (Faille et al, 2014) and the structural emplacement of the Chartreuse thrust units using the FLAMAR thermo-mechanical model (Burov et al, 2014). The hydro-mechanical modeling results highlight the calendar, distribution and magnitude of the overpressure that developed within the source-rock in the footwall of a simple fault-bend fold structure localized in the frontal part of the Chartreuse FTB. Several key geological conditions are required to create an overpressure able to fracture the shale-rocks and induce a significant change in the rheological behaviour: high TOC, low permeability, favourable structural evolution. These models highlight the importance of modeling the impact of a diffuse natural hydraulic fracturing to explain fluids propagation toward the foreland within

  11. The ongoing dome emplacement and destruction cyclic process at Popocatépetl volcano, Central Mexico

    NASA Astrophysics Data System (ADS)

    Gómez-Vazquez, Angel; De la Cruz-Reyna, Servando; Mendoza-Rosas, Ana Teresa

    2016-09-01

    The ongoing eruptive activity of Popocatépetl volcano has been characterized by emplacement and subsequent destruction of a succession of lava domes. Between the onset of the current eruption in 1994 and the time of this submission, 38 episodes of lava dome formation and removal have been identified. Each dome has showed particular features related to the magma extrusion process. Among other manifestations, dome-emplacement events have been usually accompanied by relatively low-intensity, protracted explosions referred to as exhalations. After variable times of residence, emplacements have ended in partial or total destruction of the domes by strong vulcanian explosions that produced sizeable ash plumes, with most of them also ejecting incandescent debris onto the volcano flanks. Here, we present a detailed account for the observed activity related to the domes' growth and destruction, related seismic monitoring signals, and morphological features of the domes based on 19 years of visual observations and image analysis. We then discuss a model for the process of dome growth and destruction and its hazard implications.

  12. Organic waste destruction by indirect electrooxidation

    SciTech Connect

    Leffrang, U.; Ebert, K.; Flory, K.

    1995-04-01

    The destruction of organic model substances by indirect electrooxidation was investigated. The oxidation agent Co(III) was used because of the high redox potential of the Co(III)/Co(II) redox couple (E{sub O}=1.808 V). Experiments were performed in a batch and in a continuous electrolytic cell by using various model substances (especially phenol and different chlorophenols). Intermediate and final products of the oxidation were identified and quantified. Organic carbon is ultimately transformed to CO{sub 2} and to small amounts of CO. The residual carbon in the process solution was determined by TOC measurement to be about 20 ppm. Organic chlorine is oxidized via chlorate to perchlorate. The remaining amount of adsorbable organic halogens (AOX) was less than 3 ppm. Based on these results, a pilot plant was constructed and is presently in operation.

  13. Molten salt destruction of energetic waste materials

    DOEpatents

    Brummond, William A.; Upadhye, Ravindra S.; Pruneda, Cesar O.

    1995-01-01

    A molten salt destruction process is used to treat and destroy energetic waste materials such as high explosives, propellants, and rocket fuels. The energetic material is pre-blended with a solid or fluid diluent in safe proportions to form a fluid fuel mixture. The fuel mixture is rapidly introduced into a high temperature molten salt bath. A stream of molten salt is removed from the vessel and may be recycled as diluent. Additionally, the molten salt stream may be pumped from the reactor, circulated outside the reactor for further processing, and delivered back into the reactor or cooled and circulated to the feed delivery system to further dilute the fuel mixture entering the reactor.

  14. Molten salt destruction of energetic waste materials

    DOEpatents

    Brummond, W.A.; Upadhye, R.S.; Pruneda, C.O.

    1995-07-18

    A molten salt destruction process is used to treat and destroy energetic waste materials such as high explosives, propellants, and rocket fuels. The energetic material is pre-blended with a solid or fluid diluent in safe proportions to form a fluid fuel mixture. The fuel mixture is rapidly introduced into a high temperature molten salt bath. A stream of molten salt is removed from the vessel and may be recycled as diluent. Additionally, the molten salt stream may be pumped from the reactor, circulated outside the reactor for further processing, and delivered back into the reactor or cooled and circulated to the feed delivery system to further dilute the fuel mixture entering the reactor. 4 figs.

  15. Non-destructive testing method and apparatus

    DOEpatents

    Akers, Douglas W [Idaho Falls, ID

    2011-10-04

    Non-destructive testing apparatus may comprise a photon source and a source material that emits positrons in response to bombardment of the source material with photons. The source material is positionable adjacent the photon source and a specimen so that when the source material is positioned adjacent the photon source it is exposed to photons produced thereby. When the source material is positioned adjacent the specimen, the specimen is exposed to at least some of the positrons emitted by the source material. A detector system positioned adjacent the specimen detects annihilation gamma rays emitted by the specimen. Another embodiment comprises a neutron source and a source material that emits positrons in response to neutron bombardment.

  16. Is work conducive to self-destruction?

    PubMed

    Karcher, C J; Linden, L L

    1982-01-01

    While the current literature contains numerous studies and even more numerous assumptions linking aspects of the work setting, stress, and mortality; no systematic investigation has been made of possible patterns of stress-induced self-destructive behaviors among the work settings per se. This research paper attempts to help fill that gap by reporting on an analysis of data on industry, age and mortality rates for seven stress-related causes of death (suicide, homocide, hypertensive heart disease, cirrhosis of the liver, arteriosclerotic heart disease, ulcer of the stomach, and hypertension). Using available United States' mortality statistics, a consistent pattern is found for all of the stress-related types of deaths by industry and age. A suggested explanation of this pattern is based on status integration theory.

  17. NON-DESTRUCTIVE FLAW DETECTION APPARATUS

    DOEpatents

    Stateman, M.J.; Holloway, H.R.

    1957-12-17

    An apparatus is described for the non-destructive detection of flaws in electrical conducting articles. The particular feature of the detection apparatus is that a flaw in the front or back of the test article will not be masked by signals caused by the passage of the end and front of the article through the detection apparatus. The present invention alleviates the above problem by mounting detection coils on directly opposite sides of the test passageway so that the axes of the pickup coils are perpendicular to the axis of an energizing coil through which the article is passed. A flaw in the article will cause a change in the voltage induced in one pickup coil, but passage of the end or front of the article will not produce unequal signals. The signals are compared in appropriate electrical circuitry to actuate a recorder only when unequal signals are present, indicating the presence of a flaw.

  18. Non-destructive evaluation of composites

    NASA Technical Reports Server (NTRS)

    Chu, Tsuchin Philip

    1996-01-01

    The composite materials have been used in aerospace industries for quite some time. Several non-destructive evaluation (NDE) methods have been developed to inspect composites in order to detect flaws, matrix cracking, and delamination. These methods include ultrasonics, acoustic emission, shearography, thermography, X-ray, and digital image correlation. The NDE Branch of Marshall Space Flight Center has recently acquired a thermal imaging NDE system. The same system has been used at NASA Langley Research Center for detecting disbonds. In order to compare different NDE methods, three carbon/carbon composite panels were used for experiment using ultrasonic C-scan, shearography, and thermography methods. These panels have teflon inserts to simulate the delamination between plies in a composite panel. All three methods have successfully located the insert. The experiment and results are presented in the following sections.

  19. Worse than enemies. The CEO's destructive confidant.

    PubMed

    Sulkowicz, Kerry J

    2004-02-01

    The CEO is often the most isolated and protected employee in the organization. Few leaders, even veteran CEOs, can do the job without talking to someone about their experiences, which is why most develop a close relationship with a trusted colleague, a confidant to whom they can tell their thoughts and fears. In his work with leaders, the author has found that many CEO-confidant relationships function very well. The confidants keep their leaders' best interests at heart. They derive their gratification vicariously, through the help they provide rather than through any personal gain, and they are usually quite aware that a person in their position can potentially abuse access to the CEO's innermost secrets. Unfortunately, almost as many confidants will end up hurting, undermining, or otherwise exploiting CEOs when the executives are at their most vulnerable. These confidants rarely make the headlines, but behind the scenes they do enormous damage to the CEO and to the organization as a whole. What's more, the leader is often the last one to know when or how the confidant relationship became toxic. The author has identified three types of destructive confidants. The reflector mirrors the CEO, constantly reassuring him that he is the "fairest CEO of them all." The insulator buffers the CEO from the organization, preventing critical information from getting in or out. And the usurper cunningly ingratiates himself with the CEO in a desperate bid for power. This article explores how the CEO-confidant relationship plays out with each type of adviser and suggests ways CEOs can avoid these destructive relationships.

  20. Galaxy simulation with dust formation and destruction

    NASA Astrophysics Data System (ADS)

    Aoyama, Shohei; Hou, Kuan-Chou; Shimizu, Ikkoh; Hirashita, Hiroyuki; Todoroki, Keita; Choi, Jun-Hwan; Nagamine, Kentaro

    2017-04-01

    We perform smoothed particle hydrodynamics (SPH) simulations of an isolated galaxy with a new treatment for dust formation and destruction. To this aim, we treat dust and metal production self-consistently with star formation and supernova (SN) feedback. For dust, we consider a simplified model of grain size distribution by representing the entire range of grain sizes with large and small grains. We include dust production in stellar ejecta, dust destruction by SN shocks, grain growth by accretion and coagulation and grain disruption by shattering. We find that the assumption of fixed dust-to-metal mass ratio becomes no longer valid when the galaxy is older than 0.2 Gyr, at which point the grain growth by accretion starts to contribute to the non-linear rise of dust-to-gas ratio. As expected in our previous one-zone model, shattering triggers grain growth by accretion since it increases the total surface area of grains. Coagulation becomes significant when the galaxy age is greater than ∼ 1 Gyr; at this epoch, the abundance of small grains becomes high enough to raise the coagulation rate of small grains. We further compare the radial profiles of dust-to-gas ratio (D) and dust-to-metal ratio (D/Z, i.e. depletion) at various ages with observational data. We find that our simulations broadly reproduce the radial gradients of dust-to-gas ratio and depletion. In the early epoch (≲ 0.3 Gyr), the radial gradient of D follows the metallicity gradient with D/Z determined by the dust condensation efficiency in stellar ejecta, while the D gradient is steeper than the Z gradient at the later epochs because of grain growth by accretion. The framework developed in this paper is applicable to any SPH-based galaxy evolution simulations including cosmological ones.

  1. Hypoxia and tissue destruction in pulmonary TB

    PubMed Central

    Belton, Moerida; Brilha, Sara; Manavaki, Roido; Mauri, Francesco; Nijran, Kuldip; Hong, Young T; Patel, Neva H; Dembek, Marcin; Tezera, Liku; Green, Justin; Moores, Rachel; Aigbirhio, Franklin; Al-Nahhas, Adil; Fryer, Tim D; Elkington, Paul T; Friedland, Jon S

    2016-01-01

    Background It is unknown whether lesions in human TB are hypoxic or whether this influences disease pathology. Human TB is characterised by extensive lung destruction driven by host matrix metalloproteinases (MMPs), particularly collagenases such as matrix metalloproteinase-1 (MMP-1). Methods We investigated tissue hypoxia in five patients with PET imaging using the tracer [18F]-fluoromisonidazole ([18F]FMISO) and by immunohistochemistry. We studied the regulation of MMP secretion in primary human cell culture model systems in normoxia, hypoxia, chemical hypoxia and by small interfering RNA (siRNA) inhibition. Results [18F]FMISO accumulated in regions of TB consolidation and around pulmonary cavities, demonstrating for the first time severe tissue hypoxia in man. Patlak analysis of dynamic PET data showed heterogeneous levels of hypoxia within and between patients. In Mycobacterium tuberculosis (M.tb)-infected human macrophages, hypoxia (1% pO2) upregulated MMP-1 gene expression 170-fold, driving secretion and caseinolytic activity. Dimethyloxalyl glycine (DMOG), a small molecule inhibitor which stabilises the transcription factor hypoxia-inducible factor (HIF)-1α, similarly upregulated MMP-1. Hypoxia did not affect mycobacterial replication. Hypoxia increased MMP-1 expression in primary respiratory epithelial cells via intercellular networks regulated by TB. HIF-1α and NF-κB regulated increased MMP-1 activity in hypoxia. Furthermore, M.tb infection drove HIF-1α accumulation even in normoxia. In human TB lung biopsies, epithelioid macrophages and multinucleate giant cells express HIF-1α. HIF-1α blockade, including by targeted siRNA, inhibited TB-driven MMP-1 gene expression and secretion. Conclusions Human TB lesions are severely hypoxic and M.tb drives HIF-1α accumulation, synergistically increasing collagenase activity which will lead to lung destruction and cavitation. PMID:27245780

  2. Habitat destruction and the extinction debt revisited: the Allee effect.

    PubMed

    Chen, Ling-ling; Hui, Cang; Lin, Z S

    2009-09-01

    Habitat destruction, often caused by anthropogenic disturbance, can lead to the extinction of species at an unprecedented rate. It is important, therefore, to consider habitat destruction when assessing population viability. Another factor often ignored in population viability analysis, is the Allee effect that adds to the risk of populations already on the verge of extinction. Understanding the Allee effect on species dynamics and response to habitat destruction has intrinsic value in conservation prioritization. Here, the Allee effect was considered in a multi-species hierarchical competition model. Results showed that species persistence declines dramatically due to the Allee effect, and certain species become more susceptible to habitat destruction than others. Two extinction orders emerged under habitat destruction: either the best competitor becomes extinct first or the best colonizer first. The extinction debt and order, as well as the time lag between habitat destruction and species extinction, were found to be determined by species abundance and the intensity of the Allee effect.

  3. Orthogonal fracture formation in the South Wales coalfield: implications from a field study and fluid overpressure of quartz veins

    NASA Astrophysics Data System (ADS)

    Fukunari, Tetsuzo; Gudmundsson, Agust

    2014-05-01

    Orthogonal fractures can easily make networks in geological formations and are of great importance for permeability and fluid transport in subsurface reservoirs. Despite many studies focusing on the formation of orthogonal fractures, no clear and generally accepted model has been established as yet although their formation is widely believed to occur during crustal uplift or exhumation. Here we provide new insights into their mechanism of formation based on the results of a fieldwork and analytical study of orthogonal fractures and quartz veins in alternating sand-shale layers in the South Wales coalfield, which is one of foreland basins developed in relation with north-south compression of the Variscan Orogeny. More than 3,000 fractures were measured at various localities extending from southern end to northern end of the basin. Most of the fractures in the sandstone layers, are extension fractures (mode I cracks), and become arrested at contacts with shale layers. The fractures strike north-south and east-west. Some fractures are filled with shale, probably supplied from adjacent shale layers, suggesting the shale behaved as semi-ductile material at the time of fracture formation. A remarkable observation is that most of the fractures are perpendicular to bedding planes throughout the basin. This is despite the fact that the beds are strongly folded as a result of the Variscan Orogeny. The perpendicular attitude suggests that the fracture formation somewhat predates or coincides with that of folding. This implies that the orthogonal fractures in this area did not form during crustal uplift/exhumation but rather during basin growth at the time of regional north-south convergence and associated compression of the Variscan Orogeny. By using aspect (length/thickness) ratios of quartz veins of the same geometry as the orthogonal fractures, fluid overpressure (driving pressure) at the time of fracture formation is estimated at around 33 MPa for fractures striking north

  4. Destruction of Interstellar Dust in Evolving Supernova Remnant Shock Waves

    NASA Technical Reports Server (NTRS)

    Slavin, Jonathan D.; Dwek, Eli; Jones, Anthony P.

    2015-01-01

    Supernova generated shock waves are responsible for most of the destruction of dust grains in the interstellar medium (ISM). Calculations of the dust destruction timescale have so far been carried out using plane parallel steady shocks, however that approximation breaks down when the destruction timescale becomes longer than that for the evolution of the supernova remnant (SNR) shock. In this paper we present new calculations of grain destruction in evolving, radiative SNRs. To facilitate comparison with the previous study by Jones et al. (1996), we adopt the same dust properties as in that paper. We find that the efficiencies of grain destruction are most divergent from those for a steady shock when the thermal history of a shocked gas parcel in the SNR differs significantly from that behind a steady shock. This occurs in shocks with velocities 200 km s(exp -1) for which the remnant is just beginning to go radiative. Assuming SNRs evolve in a warm phase dominated ISM, we find dust destruction timescales are increased by a factor of approximately 2 compared to those of Jones et al. (1996), who assumed a hot gas dominated ISM. Recent estimates of supernova rates and ISM mass lead to another factor of approximately 3 increase in the destruction timescales, resulting in a silicate grain destruction timescale of approximately 2-3 Gyr. These increases, while not able resolve the problem of the discrepant timescales for silicate grain destruction and creation, are an important step towards understanding the origin, and evolution of dust in the ISM.

  5. Radiocarbon dating of the Late Cycladic building and destruction phases at Akrotiri, Thera: New evidence

    NASA Astrophysics Data System (ADS)

    Maniatis, Yannis

    2012-01-01

    Akrotiri was a flourishing prehistoric settlement on the Cycladic island of Santorini (Thera) until its life was ended by a huge volcanic eruption in the LCI period. There is much debate as to when this final destruction occurred. Based on the Egyptian historical dating this happened around 1540-1530 BC, while, based on radiocarbon and other scientific data, around 1640-1600 BC. This work is an attempt to date with radiocarbon the whole settlement's life starting from the earlier phases of occupation but focusing in the sequence of the latest events. The samples, coming from the deep shafts dug in the site for the pillars of the new shelter, are pieces of wood and charcoal from house architectural elements and other constructions, including the final earthquake victims temporary camps. Therefore, the dates obtained represent the beginning of the different cultural phases plus the latest events. The results provide novel absolute dates for the commencement of the LMC and LCI Phases at Akrotiri, giving mean ranges around 1820-1790 BC and 1775-1722 BC, respectively, while the final destruction is dated around 1622-1548 BC. These results show that the LCI phase started about 100 years earlier than estimated with the Egyptian Historical chronology while the final destruction around 60 years or less earlier.

  6. Families at risk for destructive parent-child relations in adolescence.

    PubMed

    Garbarino, J; Sebes, J; Schellenbach, C

    1984-02-01

    This paper examines the parental, adolescent, and family system characteristics that place a family at risk for destructive parent-child relations in adolescence. It is based on a study of 62 families, all of which contained a youth (age 10-16) and 2 parents and were referred because of the adjustment problems of the adolescent. A 3-member team visited the family at home to administer a 3 1/2-hour battery of questionnaire, interview, and observation instruments. These included a measure of risk for destructive parent-child relations (the Adolescent-Abuse Inventory); the Achenbach Child Behavior Checklist; a measure of the family as an interactional system (FACES); the Cornell Parent Behavior Description; and assessments of adolescent physical maturation, interparental conflict, cognitive functioning, life events (A-FILE), and demographic and socioeconomic factors. The results permit identification of families as high risk for destructive parent-child relations using the parental scores on the Adolescent-Abuse Inventory. The high-risk group tends to be "chaotic" and "enmeshed" (FACES), to include more stepparents, to be more punishing and less supportive (Cornell Parent Behavior Description), and to be more stressed by life changes (A-FILE). Adolescents in the high-risk families are characterized by significantly more developmental problems (both internalizing and externalizing), and the number of such problems correlates significantly with the risk for destructive parent-child relations. The development of adolescent psychopathology appears to interact with the evolution of a high-risk family system to produce destructive relationships between parents and their adolescent offspring. Stepfamilies appear especially vulnerable to this dysfunctional evolution.

  7. NON-DESTRUCTIVE SOIL CARBON ANALYZER.

    SciTech Connect

    Wielopolski, Lucian; Hendrey, G.; Orion, I.; Prior, S.; Rogers, H.; Runion, B.; Torbert, A.

    2004-02-01

    This report describes the feasibility, calibration, and safety considerations of a non-destructive, in situ, quantitative, volumetric soil carbon analytical method based on inelastic neutron scattering (INS). The method can quantify values as low as 0.018 gC/cc, or about 1.2% carbon by weight with high precision under the instrument's configuration and operating conditions reported here. INS is safe and easy to use, residual soil activation declines to background values in under an hour, and no radiological requirements are needed for transporting the instrument. The labor required to obtain soil-carbon data is about 10-fold less than with other methods, and the instrument offers a nearly instantaneous rate of output of carbon-content values. Furthermore, it has the potential to quantify other elements, particularly nitrogen. New instrumentation was developed in response to a research solicitation from the U.S. Department of Energy (DOE LAB 00-09 Carbon Sequestration Research Program) supporting the Terrestrial Carbon Processes (TCP) program of the Office of Science, Biological and Environmental Research (BER). The solicitation called for developing and demonstrating novel techniques for quantitatively measuring changes in soil carbon. The report includes raw data and analyses of a set of proof-of-concept, double-blind studies to evaluate the INS approach in the first phase of developing the instrument. Managing soils so that they sequester massive amounts of carbon was suggested as a means to mitigate the atmospheric buildup of anthropogenic CO{sub 2}. Quantifying changes in the soils' carbon stocks will be essential to evaluating such schemes and documenting their performance. Current methods for quantifying carbon in soil by excavation and core sampling are invasive, slow, labor-intensive and locally destroy the system being observed. Newly emerging technologies, such as Laser Induced Breakdown Spectroscopy and Near-Infrared Spectroscopy, offer soil

  8. Using an infrasonic method to monitor the destruction of glaciers in Arctic conditions

    NASA Astrophysics Data System (ADS)

    Asming, V. E.; Baranov, S. V.; Vinogradov, A. N.; Vinogradov, Yu. A.; Fedorov, A. V.

    2016-09-01

    We study the application of an infrasonic method to detect infrasonic acoustic emission caused by the destruction of glaciers in the Arctic. We consider the main approaches and methods for automatic signal detection from the data of infrasonic microarrays from the viewpoint of their practical use in conditions of frequent and significant variations in the noise level characteristics of the Arctic coast. We propose a novel method for the automatic detection of infrasonic events based on representation of a plane wave signal and adaptive estimation of the noise level. The method makes it possible to detect signals with a small number of sensors (up to three) in the specific conditions of the Arctic coast. We present the results of infrasonic monitoring of the destruction of Icefjord outlet glaciers (Spitsbergen archipelago) carried out by the Kola Branch of the RAS Geophysical Survey in 2011-2012.

  9. Amplifying elements of arthritis and joint destruction.

    PubMed

    van den Berg, Wim B; van Lent, Peter L; Joosten, Leo A B; Abdollahi-Roodsaz, Shahla; Koenders, Marije I

    2007-11-01

    Rheumatoid arthritis (RA) is a systemic autoimmune disease characterised by chronic joint inflammation and variable degrees of bone and cartilage erosion. Studies in animal models of arthritis provide insight into elements which can amplify destructive features. The presence of immune complexes in the joint makes arthritis more erosive. Although considerable bone erosion still occurs in the absence of FcgammaR triggering by immune complexes, through cytokine-induced RANKL and direct osteoclast activation, cartilage erosion is heavily dependent on the FcgammaR pathway. T cell factors such as IFNgamma and IL17 further amplify erosion through upregulation of the damaging FcgammaRI and stimulation of the influx of granulocytes, respectively. Apart from immune elements, environmental pressure and components of tissue damage contribute through innate pathways. Spontaneous T cell-dependent arthritis in IL1Ra-/- mice is absent under germ-free conditions, and markedly suppressed in TLR4-deficient mice. Moreover, TLR4 blocking with a receptor antagonist suppresses erosive arthritis.

  10. Detection of weapons of mass destruction

    NASA Astrophysics Data System (ADS)

    Bjorkholm, Paul J.

    2003-07-01

    High Energy X-ray cargo screening is a mature technology that has proven its value in the detection of contraband material hidden within cargo including fully loaded sea containers. To date high energy screening has been largely applied to manifest verification and to drug detection. However, the dramatic change in world terrorism has altered the application. Now it is essential that weapons of mass destruction (WMD"s) be interdicted with incredibly high accuracy. The implication of a missed detection has gone from loss of revenue or the lowering of the street price of drugs to potentially stopping, at least for some significant time, most world commerce. Screening containers with high energy x-rays (~250+ mm of steel penetration) is capable of detecting all nuclear threats at a fraction of the strategically important mass. The screening operation can be automated so that no human decisions are required with very low false alarms. Finally, the goal of 100% inspection of cargo inbound to the United States from the twenty largest international ports is an achievable goal with hardware costs in the area of that already spent on airport security.

  11. Hodoscope Cineradiography Of Nuclear Fuel Destruction Experiments

    NASA Astrophysics Data System (ADS)

    De Volpi, A.

    1983-08-01

    Nuclear reactor safety studies have applied cineradiographic techniques to achieve key information regarding the durability of fuel elements that are subjected to destructive transients in test reactors. Beginning with its development in 1963, the fast-neutron hodoscope has recorded data at the TREAT reactor in the United States of America. Consisting of a collimator instrumented with several hundred parallel channels of detectors and associated instrumentation, the hodoscope measures fuel motion that takes place within thick-walled steel test containers. Fuel movement is determined by detecting the emission of fast neutrons induced in the test capsule by bursts of the test reactor that last from 0.3 to 30 s. The system has been designed so as to achieve under certain typical conditions( horizontal) spatial resolution less than lmm, time resolution close to lms, mass resolution below 0.1 g, with adequate dynamic range and recording duration. A variety of imaging forms have been developed to display the results of processing and analyzing recorded data.*

  12. Amplifying elements of arthritis and joint destruction

    PubMed Central

    van den Berg, Wim B; van Lent, Peter L; Joosten, Leo A B; Abdollahi‐Roodsaz, Shahla; Koenders, Marije I

    2007-01-01

    Rheumatoid arthritis (RA) is a systemic autoimmune disease characterised by chronic joint inflammation and variable degrees of bone and cartilage erosion. Studies in animal models of arthritis provide insight into elements which can amplify destructive features. The presence of immune complexes in the joint makes arthritis more erosive. Although considerable bone erosion still occurs in the absence of FcγR triggering by immune complexes, through cytokine‐induced RANKL and direct osteoclast activation, cartilage erosion is heavily dependent on the FcγR pathway. T cell factors such as IFNγ and IL17 further amplify erosion through upregulation of the damaging FcγRI and stimulation of the influx of granulocytes, respectively. Apart from immune elements, environmental pressure and components of tissue damage contribute through innate pathways. Spontaneous T cell‐dependent arthritis in IL1Ra–/– mice is absent under germ‐free conditions, and markedly suppressed in TLR4‐deficient mice. Moreover, TLR4 blocking with a receptor antagonist suppresses erosive arthritis. PMID:17934095

  13. Photocatalytic destruction of automobile exhaust emissions

    SciTech Connect

    Kaviranta, P.D.; Peden, C.H.F.

    1996-10-01

    Hydrocarbons, carbon monoxide, and nitrogen oxides contained in automobile exhaust emissions are among the major atmospheric air pollutants. During the first few minutes of a cold start of the engine, the emission levels of unburned hydrocarbon and CO pollutants are very high due to the inefficiency of the cold engine and the poor activity of the catalysts lower temperatures. Therefore, it is necessary to provide an alternative approach to deal with this specific problem in order to meet near-term regulatory requirements. Our approach has been to use known photocatalytic reactions obtainable on semiconducting powders such as titanium dioxide. In this presentation we describe our recent studies aimed at the photocatalytic reduction of unburned hydrocarbons and carbon monoxide in automobile exhaust emissions. Our results demonstrate the effective destruction of propylene into water and carbon dioxide. The conversion was found to be dependent on the propylene flow rate. The reaction rate was studied as a function of time, humidity and temperature. The effect of the power of the UV source on conversion will also be presented.

  14. The preventive destruction of a hazardous asteroid

    NASA Astrophysics Data System (ADS)

    Aleksandrova, A. G.; Galushina, T. Yu.; Prishchepenko, A. B.; Kholshevnikov, K. V.; Chechetkin, V. M.

    2016-06-01

    One means of countering a hazardous asteroid is discussed: destruction of the object using a nuclear charge. Explosion of such an asteroid shortly before its predicted collision would have catastrophic consequences, with numerous highly radioactive fragments falling onto the Earth. The possibility of exploding the asteroid several years before its impact is also considered. Such an approach is made feasible because the vast majority of hazardous objects pass by the Earth several times before colliding with it. Computations show that, in the 10 years following the explosion, only a negligible number of fragments fall onto the Earth, whose radioactivity has substantially reduced during this time. In most cases, none of these fragments collides with the Earth. Thus, this proposed method for eliminating a threat from space is reasonable in at least two cases: when it is not possible to undergo a soft removal of the object from the collisional path, and to destroy objects that are continually returning to near-Earth space and require multiple removals from hazardous orbits.

  15. Aseismic blocks and destructive earthquakes in the Aegean

    NASA Astrophysics Data System (ADS)

    Stiros, Stathis

    2017-04-01

    Aseismic areas are not identified only in vast, geologically stable regions, but also within regions of active, intense, distributed deformation such as the Aegean. In the latter, "aseismic blocks" about 200m wide were recognized in the 1990's on the basis of the absence of instrumentally-derived earthquake foci, in contrast to surrounding areas. This pattern was supported by the available historical seismicity data, as well as by geologic evidence. Interestingly, GPS evidence indicates that such blocks are among the areas characterized by small deformation rates relatively to surrounding areas of higher deformation. Still, the largest and most destructive earthquake of the 1990's, the 1995 M6.6 earthquake occurred at the center of one of these "aseismic" zones at the northern part of Greece, found unprotected against seismic hazard. This case was indeed a repeat of the case of the tsunami-associated 1956 Amorgos Island M7.4 earthquake, the largest 20th century event in the Aegean back-arc region: the 1956 earthquake occurred at the center of a geologically distinct region (Cyclades Massif in Central Aegean), till then assumed aseismic. Interestingly, after 1956, the overall idea of aseismic regions remained valid, though a "promontory" of earthquake prone-areas intruding into the aseismic central Aegean was assumed. Exploitation of the archaeological excavation evidence and careful, combined analysis of historical and archaeological data and other palaeoseismic, mostly coastal data, indicated that destructive and major earthquakes have left their traces in previously assumed aseismic blocks. In the latter earthquakes typically occur with relatively low recurrence intervals, >200-300 years, much smaller than in adjacent active areas. Interestingly, areas assumed a-seismic in antiquity are among the most active in the last centuries, while areas hit by major earthquakes in the past are usually classified as areas of low seismic risk in official maps. Some reasons

  16. The most destructive effusive eruption in modern history: Nyiragongo (RD. Congo), January 2002.

    NASA Astrophysics Data System (ADS)

    Allard, P.; Baxter, P.; Halbwachs, M.; Kasareka, M.; Komorowski, J. C.; Joron, J. L.

    2003-04-01

    Nyiragongo volcano (3470 m a.s.l.), built on the western branch of the East African Rift, has long contained in its summit crater a highly fluid, actively degassing lava lake of nephelinite composition that was studied on several occasions since the mid XXth century [1]. In 1977, for the first time in recent history, this lava lake suddenly drained out through flank fractures, causing some 60 casualties [2]. A new lava lake gradually refilled the crater from 1982 to 1994 [3] but, subsequently, its surface solidification evidenced a drop in the magma supply rate. On 17 January 2002, after several months of increased seismicity and fumarolic activity, a second drainage of the lava lake occurred through a 18 km long N-S fracture system that propagated in a few hours from 2800 m down to 1550 m elevation along the southern volcano flank. Voluminous flows of fluid pahoehoe and aa lavas ran across villages, banana fields and crops and, finally, through the city of Goma from which 350,000 inhabitants fled in a hurry. About 15% of the city, including its main centre and the housing of 120,000 people, were engulfed by flows which ultimately poured into the nearby gas-charged Lake Kivu, raising concern about a possible Nyos-type lethal gas burst [4]. Despite its limited death toll (about 45), this eruption had the most destructive impact ever recorded in history for an effusive eruption. Understanding its triggering mechanism is fundamental since a new lava lake may reform soon in Nyiragongo crater, further threatening the Goma region. Different field observations and measurements carried out soon after the eruption allowed us [4] and UN-OCHA colleagues [5] to recognize that the 2002 eruption had likely been triggered by tectonic spreading of the Kivu Rift, manifested in the occurrence of intense post-eruptive seismicity, regional ground subsidence, fracturing and minor CO2-CH4-rich gas explosions, rather than by simple magma overpressure and intrusion. This interpretation is

  17. 50 CFR 28.43 - Destruction of dogs and cats.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 9 2014-10-01 2014-10-01 false Destruction of dogs and cats. 28.43 Section 28.43 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR... VIOLATIONS OF PARTS 25, 26, AND 27 Impoundment Procedures § 28.43 Destruction of dogs and cats. Dogs and cats...

  18. 50 CFR 28.43 - Destruction of dogs and cats.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 9 2012-10-01 2012-10-01 false Destruction of dogs and cats. 28.43 Section 28.43 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR... VIOLATIONS OF PARTS 25, 26, AND 27 Impoundment Procedures § 28.43 Destruction of dogs and cats. Dogs and cats...

  19. 50 CFR 28.43 - Destruction of dogs and cats.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 9 2013-10-01 2013-10-01 false Destruction of dogs and cats. 28.43 Section 28.43 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR... VIOLATIONS OF PARTS 25, 26, AND 27 Impoundment Procedures § 28.43 Destruction of dogs and cats. Dogs and cats...

  20. 50 CFR 28.43 - Destruction of dogs and cats.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Destruction of dogs and cats. 28.43 Section 28.43 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR... VIOLATIONS OF PARTS 25, 26, AND 27 Impoundment Procedures § 28.43 Destruction of dogs and cats. Dogs and cats...

  1. 50 CFR 28.43 - Destruction of dogs and cats.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Destruction of dogs and cats. 28.43 Section 28.43 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR... VIOLATIONS OF PARTS 25, 26, AND 27 Impoundment Procedures § 28.43 Destruction of dogs and cats. Dogs and cats...

  2. Self-Destructive Behavior in People with Dissociative Disorders.

    ERIC Educational Resources Information Center

    Saxe, Glenn N.; Chawla, Neharika; Van der Kolk, Bessel

    2002-01-01

    Study assesses self-destructive behavior in a group of inpatients who have dissociative disorders compared to those who report few dissociative symptoms. Results reveal that these patients more frequently engage in self-destructive behaviors, use more methods of self-injury, and begin to injure themselves at an earlier age then patients who do not…

  3. 19 CFR 191.44 - Destruction under Customs supervision.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Destruction under Customs supervision. 191.44 Section 191.44 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) DRAWBACK Rejected Merchandise § 191.44 Destruction under...

  4. 19 CFR 191.25 - Destruction under Customs supervision.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Destruction under Customs supervision. 191.25 Section 191.25 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) DRAWBACK Manufacturing Drawback § 191.25 Destruction under...

  5. 27 CFR 479.24 - Destructive device determination.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2012-04-01 2010-04-01 true Destructive device determination. 479.24 Section 479.24 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS, DESTRUCTIVE DEVICES...

  6. 27 CFR 479.24 - Destructive device determination.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Destructive device determination. 479.24 Section 479.24 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS, DESTRUCTIVE DEVICES...

  7. 27 CFR 479.24 - Destructive device determination.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2011-04-01 2010-04-01 true Destructive device determination. 479.24 Section 479.24 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS, DESTRUCTIVE DEVICES...

  8. 27 CFR 479.24 - Destructive device determination.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2014-04-01 2014-04-01 false Destructive device determination. 479.24 Section 479.24 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS, DESTRUCTIVE DEVICES...

  9. 27 CFR 479.24 - Destructive device determination.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2013-04-01 2013-04-01 false Destructive device determination. 479.24 Section 479.24 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS, DESTRUCTIVE DEVICES...

  10. 27 CFR 25.221 - Voluntary destruction of beer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... beer. 25.221 Section 25.221 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS BEER Voluntary Destruction § 25.221 Voluntary destruction of beer. (a) On brewery premises. (1) A brewer may destroy, at the brewery, beer on which the tax has...

  11. 32 CFR 644.494 - Donation, abandonment or destruction.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Donation, abandonment or destruction. 644.494 Section 644.494 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL... Land) § 644.494 Donation, abandonment or destruction. (a) General. Improvements may be...

  12. 21 CFR 884.4500 - Obstetric fetal destructive instrument.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Obstetric fetal destructive instrument. 884.4500 Section 884.4500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... destructive instrument is a device designed to crush or pull the fetal body to facilitate the delivery of...

  13. Self-Destructive Behavior in People with Dissociative Disorders.

    ERIC Educational Resources Information Center

    Saxe, Glenn N.; Chawla, Neharika; Van der Kolk, Bessel

    2002-01-01

    Study assesses self-destructive behavior in a group of inpatients who have dissociative disorders compared to those who report few dissociative symptoms. Results reveal that these patients more frequently engage in self-destructive behaviors, use more methods of self-injury, and begin to injure themselves at an earlier age then patients who do not…

  14. 49 CFR 15.19 - Destruction of SSI.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Destruction of SSI. 15.19 Section 15.19... Destruction of SSI. (a) DOT. Subject to the requirements of the Federal Records Act (5 U.S.C. 105), including... essential transactions, DOT destroys SSI when no longer needed to carry out the agency's function. (b) Other...

  15. 9 CFR 54.7 - Procedures for destruction of animals.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Procedures for destruction of animals. 54.7 Section 54.7 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT... SCRAPIE Scrapie Indemnification Program § 54.7 Procedures for destruction of animals. (a) Scrapie-positive...

  16. 9 CFR 2.129 - Confiscation and destruction of animals.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Confiscation and destruction of animals. 2.129 Section 2.129 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Miscellaneous § 2.129 Confiscation and destruction of...

  17. 9 CFR 2.129 - Confiscation and destruction of animals.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Confiscation and destruction of animals. 2.129 Section 2.129 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Miscellaneous § 2.129 Confiscation and destruction of...

  18. 9 CFR 2.129 - Confiscation and destruction of animals.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Confiscation and destruction of animals. 2.129 Section 2.129 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Miscellaneous § 2.129 Confiscation and destruction of...

  19. 9 CFR 54.7 - Procedures for destruction of animals.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Procedures for destruction of animals. 54.7 Section 54.7 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT... SCRAPIE Scrapie Indemnification Program § 54.7 Procedures for destruction of animals. (a) Scrapie-positive...

  20. 9 CFR 54.7 - Procedures for destruction of animals.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Procedures for destruction of animals. 54.7 Section 54.7 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT... SCRAPIE Scrapie Indemnification Program § 54.7 Procedures for destruction of animals. (a) Scrapie-positive...

  1. 9 CFR 2.129 - Confiscation and destruction of animals.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Confiscation and destruction of animals. 2.129 Section 2.129 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Miscellaneous § 2.129 Confiscation and destruction of...

  2. 9 CFR 2.129 - Confiscation and destruction of animals.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Confiscation and destruction of animals. 2.129 Section 2.129 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Miscellaneous § 2.129 Confiscation and destruction of...

  3. 9 CFR 54.7 - Procedures for destruction of animals.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Procedures for destruction of animals. 54.7 Section 54.7 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT... SCRAPIE Scrapie Indemnification Program § 54.7 Procedures for destruction of animals. (a) Scrapie-positive...

  4. 9 CFR 54.7 - Procedures for destruction of animals.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Procedures for destruction of animals. 54.7 Section 54.7 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT... SCRAPIE Scrapie Indemnification Program § 54.7 Procedures for destruction of animals. (a) Scrapie-positive...

  5. 27 CFR 25.221 - Voluntary destruction of beer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... beer. 25.221 Section 25.221 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS BEER Voluntary Destruction § 25.221 Voluntary destruction of beer. (a) On brewery premises. (1) A brewer may destroy, at the brewery, beer on which the tax has...

  6. 27 CFR 25.221 - Voluntary destruction of beer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... beer. 25.221 Section 25.221 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL BEER Voluntary Destruction § 25.221 Voluntary destruction of beer. (a) On brewery premises. (1) A brewer may destroy, at the brewery, beer on which the tax has...

  7. 27 CFR 25.221 - Voluntary destruction of beer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... beer. 25.221 Section 25.221 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL BEER Voluntary Destruction § 25.221 Voluntary destruction of beer. (a) On brewery premises. (1) A brewer may destroy, at the brewery, beer on which the tax has...

  8. 27 CFR 25.221 - Voluntary destruction of beer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... beer. 25.221 Section 25.221 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS BEER Voluntary Destruction § 25.221 Voluntary destruction of beer. (a) On brewery premises. (1) A brewer may destroy, at the brewery, beer on which the tax has...

  9. 27 CFR 24.294 - Destruction of wine.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Destruction of wine. 24..., DEPARTMENT OF THE TREASURY ALCOHOL WINE Removal, Return and Receipt of Wine Removals Without Payment of Tax § 24.294 Destruction of wine. (a) General. Wine on bonded wine premises may be destroyed on or off wine...

  10. 27 CFR 24.294 - Destruction of wine.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Destruction of wine. 24..., DEPARTMENT OF THE TREASURY LIQUORS WINE Removal, Return and Receipt of Wine Removals Without Payment of Tax § 24.294 Destruction of wine. (a) General. Wine on bonded wine premises may be destroyed on or off wine...

  11. 27 CFR 24.294 - Destruction of wine.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Destruction of wine. 24..., DEPARTMENT OF THE TREASURY LIQUORS WINE Removal, Return and Receipt of Wine Removals Without Payment of Tax § 24.294 Destruction of wine. (a) General. Wine on bonded wine premises may be destroyed on or off wine...

  12. 27 CFR 24.294 - Destruction of wine.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Destruction of wine. 24..., DEPARTMENT OF THE TREASURY LIQUORS WINE Removal, Return and Receipt of Wine Removals Without Payment of Tax § 24.294 Destruction of wine. (a) General. Wine on bonded wine premises may be destroyed on or off wine...

  13. 27 CFR 24.294 - Destruction of wine.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Destruction of wine. 24..., DEPARTMENT OF THE TREASURY ALCOHOL WINE Removal, Return and Receipt of Wine Removals Without Payment of Tax § 24.294 Destruction of wine. (a) General. Wine on bonded wine premises may be destroyed on or off wine...

  14. Principles in the Psychotherapy of Self-Destructive Borderline Patients

    PubMed Central

    PLAKUN, ERIC M.

    1994-01-01

    Patients with borderline personality disorder often exhibit lethal or nonlethal self-destructive behavior. The author offers seven principles for establishing and maintaining a therapeutic alliance in the insight-oriented psychodynamic psychotherapy of borderline personality disorder patients with self-destructive behavior serious enough to threaten the continuity of the therapy. PMID:22700187

  15. 10 CFR 52.10 - Attacks and destructive acts.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 2 2012-01-01 2012-01-01 false Attacks and destructive acts. 52.10 Section 52.10 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS General Provisions § 52.10 Attacks and destructive acts. Neither an applicant for a license to manufacture...

  16. 10 CFR 52.10 - Attacks and destructive acts.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Attacks and destructive acts. 52.10 Section 52.10 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS General Provisions § 52.10 Attacks and destructive acts. Neither an applicant for a license to manufacture...

  17. 10 CFR 52.10 - Attacks and destructive acts.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 2 2014-01-01 2014-01-01 false Attacks and destructive acts. 52.10 Section 52.10 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS General Provisions § 52.10 Attacks and destructive acts. Neither an applicant for a license to manufacture...

  18. 10 CFR 52.10 - Attacks and destructive acts.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false Attacks and destructive acts. 52.10 Section 52.10 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS General Provisions § 52.10 Attacks and destructive acts. Neither an applicant for a license to manufacture...

  19. 10 CFR 52.10 - Attacks and destructive acts.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 2 2013-01-01 2013-01-01 false Attacks and destructive acts. 52.10 Section 52.10 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS General Provisions § 52.10 Attacks and destructive acts. Neither an applicant for a license to manufacture...

  20. Willingness to pay for defense against weapons of mass destruction.

    PubMed

    Mulvaney, J M; LaBarre, D; Pastel, R; Landauer, M

    2001-12-01

    A survey assessed the willingness to pay for defense against weapons of mass destruction. The results were evaluated according to the benefit to society. The results indicated preferences for increased spending on intelligence gathering, training, and equipment. We concluded that the United States is spending less for weapons of mass destruction defense than the sample population was willing to pay.

  1. 9 CFR 51.25 - Proof of destruction.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Proof of destruction. 51.25 Section 51.25 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... Indemnity for Sheep, Goats, and Horses § 51.25 Proof of destruction. The Veterinarian in Charge will...

  2. 9 CFR 51.25 - Proof of destruction.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Proof of destruction. 51.25 Section 51.25 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... Indemnity for Sheep, Goats, and Horses § 51.25 Proof of destruction. The Veterinarian in Charge will...

  3. Destructive Leadership: The Hatfield and McCoy Feud

    ERIC Educational Resources Information Center

    Sparks, George; Wolf, Patricia; Zurick, Andryce M.

    2015-01-01

    This paper explores the phenomenon of destructive leadership using the historical case study of the feud between the Hatfields and McCoys. The characteristics of destructive leadership as well as the consequences of this leadership style are reviewed, examined and analyzed. Utilizing a case from history to shine light on a contemporary problem,…

  4. EVENT SEGMENTATION

    PubMed Central

    Zacks, Jeffrey M.; Swallow, Khena M.

    2012-01-01

    One way to understand something is to break it up into parts. New research indicates that segmenting ongoing activity into meaningful events is a core component of ongoing perception, with consequences for memory and learning. Behavioral and neuroimaging data suggest that event segmentation is automatic and that people spontaneously segment activity into hierarchically organized parts and sub-parts. This segmentation depends on the bottom-up processing of sensory features such as movement, and on the top-down processing of conceptual features such as actors’ goals. How people segment activity affects what they remember later; as a result, those who identify appropriate event boundaries during perception tend to remember more and learn more proficiently. PMID:22468032

  5. Abnormal organic-matter maturation in the Yinggehai Basin, South China Sea: Implications for hydrocarbon expulsion and fluid migration from overpressured systems

    USGS Publications Warehouse

    Hao, F.; Li, S.; Dong, W.; Hu, Z.; Huang, B.

    1998-01-01

    Three superimposed pressure systems are present in the Yinggehai Basin, South China Sea. A number of commercial, thermogenic gas accumulations have been found in an area in which shale diapirs occur. Because the reservoir intervals are shallow and very young, they must have filled with gas rapidly. The thick (up to 17 km) Tertiary and Quaternary sedimentary succession is dominated by shales, and is not disrupted by major faulting in the study area, a factor which seems to have had an important effect on both hydrocarbon generation and fluid migration. Organic-matter maturation in the deepest, most overpressured compartment has been significantly retarded as a result of the combined effects of excess pressure, the presence of large volumes of water, and the retention of generated hydrocarbons. This retardation is indicated by both kerogen-related parameters (vitrinite reflectance and Rock-Eval T(max)); and also by parameters based on the analysis of soluble organic matter (such as the C15+ hydrocarbon content, and the concentration of isoprenoid hydrocarbons relative to adjacent normal alkanes). In contrast to this, organic-matter maturation in shallow, normally-pressured strata in the diapiric area has been enhanced by hydrothermal fluid flow, which is clearly not topography-driven in origin. As a result, the hydrocarbon generation 'window' in the basin is considerably wider than could be expected from traditional geochemical modelling. These two unusual and contrasting anomalies in organic-matter maturation, together with other lines of evidence, suggest that there was a closed fluid system in the overpressured compartment until shale diapirs developed. The diapirs developed as a result of the intense overpressuring, and their growth was triggered by regional extensional stresses. They served as conduits through which fluids (both water and hydrocarbons) retained in the closed system could rapidly migrate. Fluid migration led to the modification of the thermal

  6. [Middle ear overpressure with Meniett in Menière disease: indications, results at short and middle terms in 53 cases].

    PubMed

    Faict, H; Bouccara, D

    2007-01-01

    To expose the results obtained at short and middle terms and the tolerance of over pressure treatment with Meniett in Menière disease. A pressure treatment using Meniett device was initiated for 53 patients suffering of unilateral or bilateral active Menière's disease, despite medical treatment and physiotherapy. Retrospective analysis of the data demonstrate i) no complications due to the tympanostomy tube, ii) with a 4 months follow up after the treatment, a total control or reduction of vertigo in respectively 65% and 24.5% of the initially treated patients. The overpressure treatment with Meniett has been well tolerated. It can be repeated in case of recurrence of the symptoms. It is an interesting alternative for the treatment of Menière disease.

  7. Ecology: death and destruction determine diversity.

    PubMed

    Brockhurst, Michael A

    2007-07-03

    Death can be good, bad or indifferent for biodiversity. New work confirms that predators can drive diversification of prey even in homogeneous environments, but suggests that this effect is crucially dependent upon the frequency and intensity of other mass-mortality events.

  8. Horseradish Peroxidase Inactivation: Heme Destruction and Influence of Polyethylene Glycol

    PubMed Central

    Mao, Liang; Luo, Siqiang; Huang, Qingguo; Lu, Junhe

    2013-01-01

    Horseradish peroxidase (HRP) mediates efficient conversion of many phenolic contaminants and thus has potential applications for pollution control. Such potentially important applications suffer however from the fact that the enzyme becomes quickly inactivated during phenol oxidation and polymerization. The work here provides the first experimental data of heme consumption and iron releases to support the hypothesis that HRP is inactivated by heme destruction. Product of heme destruction is identified using liquid chromatography with mass spectrometry. The heme macrocycle destruction involving deprivation of the heme iron and oxidation of the 4-vinyl group in heme occurs as a result of the reaction. We also demonstrated that heme consumption and iron releases resulting from HRP destruction are largely reduced in the presence of polyethylene glycol (PEG), providing the first evidence to indicate that heme destruction is effectively suppressed by co-dissolved PEG. These findings advance a better understanding of the mechanisms of HRP inactivation. PMID:24185130

  9. Horseradish peroxidase inactivation: heme destruction and influence of polyethylene glycol.

    PubMed

    Mao, Liang; Luo, Siqiang; Huang, Qingguo; Lu, Junhe

    2013-11-04

    Horseradish peroxidase (HRP) mediates efficient conversion of many phenolic contaminants and thus has potential applications for pollution control. Such potentially important applications suffer however from the fact that the enzyme becomes quickly inactivated during phenol oxidation and polymerization. The work here provides the first experimental data of heme consumption and iron releases to support the hypothesis that HRP is inactivated by heme destruction. Product of heme destruction is identified using liquid chromatography with mass spectrometry. The heme macrocycle destruction involving deprivation of the heme iron and oxidation of the 4-vinyl group in heme occurs as a result of the reaction. We also demonstrated that heme consumption and iron releases resulting from HRP destruction are largely reduced in the presence of polyethylene glycol (PEG), providing the first evidence to indicate that heme destruction is effectively suppressed by co-dissolved PEG. These findings advance a better understanding of the mechanisms of HRP inactivation.

  10. Cerebrospinal Fluid Chemokine (C-C Motif) Ligand 2 Is an Early-Response Biomarker for Blast-Overpressure-Wave-Induced Neurotrauma in Rats.

    PubMed

    Wang, Ying; Wei, Yanling; Oguntayo, Samuel; Wilder, Donna; Tong, Lawrence; Su, Yan; Gist, Irene; Arun, Peethambaran; Long, Joseph B

    2017-02-15

    Chemokines and their receptors are of great interest within the milieu of immune responses elicited in the central nervous system in response to trauma. Chemokine (C-C motif)) ligand 2 (CCL2), which is also known as monocyte chemotactic protein-1, has been implicated in the pathogenesis of traumatic brain injury (TBI), brain ischemia, Alzheimer's disease, and other neurodegenerative diseases. In this study, we investigated the time course of CCL2 accumulation in cerebrospinal fluid (CSF) after exposures to single and repeated blast overpressures of varied intensities along with the neuropathological changes and motor deficits resulting from these blast conditions. Significantly increased concentrations of CCL2 in CSF were evident by 1 h of blast exposure and persisted over 24 h with peak levels measured at 6 h post-injury. The increased levels of CCL2 in CSF corresponded with both the number and intensities of blast overpressure and were also commensurate with the extent of neuromotor impairment and neuropathological abnormalities resulting from these exposures. CCL2 levels in CSF and plasma were tightly correlated with levels of CCL2 messenger RNA in cerebellum, the brain region most consistently neuropathologically disrupted by blast. In view of the roles of CCL2 that have been implicated in multiple neurodegenerative disorders, it is likely that the sustained high levels of CCL2 and the increased expression of its main receptor, CCR2, in the brain after blast may similarly contribute to neurodegenerative processes after blast exposure. In addition, the markedly elevated concentration of CCL2 in CSF might be a candidate early-response biomarker for diagnosis and prognosis of blast-induced TBI.

  11. Transformational Events

    ERIC Educational Resources Information Center

    Denning, Peter J.; Hiles, John E.

    2006-01-01

    Transformational Events is a new pedagogic pattern that explains how innovations (and other transformations) happened. The pattern is three temporal stages: an interval of increasingly unsatisfactory ad hoc solutions to a persistent problem (the "mess"), an offer of an invention or of a new way of thinking, and a period of widespread adoption and…

  12. Transformational Events

    ERIC Educational Resources Information Center

    Denning, Peter J.; Hiles, John E.

    2006-01-01

    Transformational Events is a new pedagogic pattern that explains how innovations (and other transformations) happened. The pattern is three temporal stages: an interval of increasingly unsatisfactory ad hoc solutions to a persistent problem (the "mess"), an offer of an invention or of a new way of thinking, and a period of widespread adoption and…

  13. Non destructive testing of soft body armor

    NASA Astrophysics Data System (ADS)

    Bhise, Karan

    Pristine bullet proof vests are extremely effective at halting pre-determined projectile threats and have saved over 3000 lives. However, the effectiveness of these vests to halt a bullet is seen to decrease over time.Owing to the importance of bullet proof vests over a period of time, tests to determine their effectiveness have been carried out on every batch of vests at the time of inception and at certain time intervals by shooting a bullet through them. A few vests from every batch are picked up and shot at to check for bullet penetration during this process while these results are extrapolated onto the other vests from the batch.One of the main issues with this method is the fact that testing a few jackets among a large set of jackets does not guarantee the safety of every jacket in the entire batch.Further the jackets that are shot-at have the possibility of undergoing substantial damage during the process thus compromising its safety rendering them unsafe for future use.As the vest penetration phenomenon is extremely complex too, there arose a need for a better testing procedure that could not only help ensure more safety, but also save time and money.The new testing procedure proposed a non-destructive evaluation of the jackets that would solve the issues previous faced in testing the vests. This would lead to the building of a portable set up which could be carried to any location to test jackets in a matter of minutes thus saving time and money.

  14. Cryogenic Storage Tank Non-Destructive Evaluation

    NASA Technical Reports Server (NTRS)

    Arens, Ellen

    2010-01-01

    This slide presentation reviews the work in non-destructive evaluation (NDE) of cryogenic storage tanks. Four large cryogenic tanks, constructed in 1965 with perlite insulation in the annular regions, are of concern. The construction of the tanks, two Liquid Oxygen (LOX) and two Liquid Hydrogen (LH2), are described. The loss rate for the LOX tank at Pad A is slightly higher than that for the one at Pad B. The concerns for the LH2 tank at Pad B are that there is a significantly higher boil-off rate than that at Pad A, that there is mold growth, indicative of increased heat flow, that there is a long down-time needed for repairs, and that 3 of 5 full thermal cycles have been used on the Pad B LH2 tank. The advantages and disadvantages of thermal imaging are given. A detailed description of what is visible of the structures in the infra-red is given and views of the thermal images are included. Missing Perlite is given as the probable cause of the cold spot on the Pad B LH2 tank. There is no indications of problematic cold regions on the Pad A LH2 tank, as shown by the thermal images given in the presentation. There is definite indication of a cold region on the Pad A LOX tank. There is however concerns with thermal imaging, as thermal images can be significantly effected by environmental conditions, image differences on similar days but with different wind speeds. Other effects that must be considered include ambient temperature, humidity levels/dew, and cloud reflections

  15. PROCESSING ALTERNATIVES FOR DESTRUCTION OF TETRAPHENYLBORATE

    SciTech Connect

    Lambert, D; Thomas Peters, T; Samuel Fink, S

    2007-02-27

    Two processes were chosen in the 1980's at the Savannah River Site (SRS) to decontaminate the soluble High Level Waste (HLW). The In Tank Precipitation (ITP) process (1,2) was developed at SRS for the removal of radioactive cesium and actinides from the soluble HLW. Sodium tetraphenylborate was added to the waste to precipitate cesium and monosodium titanate (MST) was added to adsorb actinides, primarily uranium and plutonium. Two products of this process were a low activity waste stream and a concentrated organic stream containing cesium tetraphenylborate and actinides adsorbed on monosodium titanate (MST). A copper catalyzed acid hydrolysis process was built to process (3, 4) the Tank 48H cesium tetraphenylborate waste in the SRS's Defense Waste Processing Facility (DWPF). Operation of the DWPF would have resulted in the production of benzene for incineration in SRS's Consolidated Incineration Facility. This process was abandoned together with the ITP process in 1998 due to high benzene in ITP caused by decomposition of excess sodium tetraphenylborate. Processing in ITP resulted in the production of approximately 1.0 million liters of HLW. SRS has chosen a solvent extraction process combined with adsorption of the actinides to decontaminate the soluble HLW stream (5). However, the waste in Tank 48H is incompatible with existing waste processing facilities. As a result, a processing facility is needed to disposition the HLW in Tank 48H. This paper will describe the process for searching for processing options by SRS task teams for the disposition of the waste in Tank 48H. In addition, attempts to develop a caustic hydrolysis process for in tank destruction of tetraphenylborate will be presented. Lastly, the development of both a caustic and acidic copper catalyzed peroxide oxidation process will be discussed.

  16. VOC Destruction by Catalytic Combustion Microturbine

    SciTech Connect

    Tom Barton

    2009-03-10

    This project concerned the application of a catalytic combustion system that has been married to a micro-turbine device. The catalytic combustion system decomposes the VOC's and transmits these gases to the gas turbine. The turbine has been altered to operate on very low-level BTU fuels equivalent to 1.5% methane in air. The performance of the micro-turbine for VOC elimination has some flexibility with respect to operating conditions, and the system is adaptable to multiple industrial applications. The VOC source that was been chosen for examination was the emissions from coal upgrading operations. The overall goal of the project was to examine the effectiveness of a catalytic combustion based system for elimination of VOCs while simultaneously producing electrical power for local consumption. Project specific objectives included assessment of the feasibility for using a Flex-Microturbine that generates power from natural gas while it consumes VOCs generated from site operations; development of an engineering plan for installation of the Flex-Microturbine system; operation of the micro-turbine through various changes in site and operation conditions; measurement of the VOC destruction quantitatively; and determination of the required improvements for further studies. The micro-turbine with the catalytic bed worked effectively to produce power on levels of fuel much lower than the original turbine design. The ability of the device to add or subtract supplemental fuel to augment the amount of VOC's in the inlet air flow made the device an effective replacement for a traditional flare. Concerns about particulates in the inlet flow and the presence of high sulfur concentrations with the VOC mixtures was identified as a drawback with the current catalytic design. A new microturbine design was developed based on this research that incorporates a thermal oxidizer in place of the catalytic bed for applications where particulates or contamination would limit the lifetime of

  17. NITRATE DESTRUCTION LITERATURE SURVEY AND EVALUATION CRITERIA

    SciTech Connect

    Steimke, J.

    2011-02-01

    This report satisfies the initial phase of Task WP-2.3.4 Alternative Sodium Recovery Technology, Subtask 1; Develop Near-Tank Nitrate/Nitrite Destruction Technology. Some of the more common anions in carbon steel waste tanks at SRS and Hanford Site are nitrate which is corrosive, and nitrite and hydroxide which are corrosion inhibitors. At present it is necessary to periodically add large quantities of 50 wt% caustic to waste tanks. There are three primary reasons for this addition. First, when the contents of salt tanks are dissolved, sodium hydroxide preferentially dissolves and is removed. During the dissolution process the concentration of free hydroxide in the tank liquid can decrease from 9 M to less than 0.2 M. As a result, roughly half way through the dissolution process large quantities of sodium hydroxide must be added to the tank to comply with requirements for corrosion control. Second, hydroxide is continuously consumed by reaction with carbon dioxide which occurs naturally in purge air used to prevent buildup of hydrogen gas inside the tanks. The hydrogen is generated by radiolysis of water. Third, increasing the concentration of hydroxide increases solubility of some aluminum compounds, which is desirable in processing waste. A process that converts nitrate and nitrite to hydroxide would reduce certain costs. (1) Less caustic would be purchased. (2) Some of the aluminum solid compounds in the waste tanks would become more soluble so less mass of solids would be sent to High Level Vitrification and therefore it would be not be necessary to make as much expensive high level vitrified product. (3) Less mass of sodium would be fed to Saltstone at SRS or Low Level Vitrification at Hanford Site so it would not be necessary to make as much low level product. (4) At SRS less nitrite and nitrate would be sent to Defense Waste Processing Facility (DWPF) so less formic acid would be consumed there and less hydrogen gas would be generated. This task involves

  18. Thermal Destruction of TETS: Experiments and Modeling ...

    EPA Pesticide Factsheets

    Symposium Paper In the event of a contamination event involving chemical warfare agents (CWAs) or toxic industrial chemicals (TICs), large quantities of potentially contaminated materials, both indoor and outdoor, may be treated with thermal incineration during the site remediation process. Even if the CWAs or TICs of interest are not particularly thermally stable and might be expected to decompose readily in a high temperature combustion environment, the refractory nature of many materials found inside and outside buildings may present heat transfer challenges in an incineration system depending on how the materials are packaged and fed into the incinerator. This paper reports on a study to examine the thermal decomposition of a banned rodenticide, tetramethylene disulfotetramine (TETS) in a laboratory reactor, analysis of the results using classical reactor design theory, and subsequent scale-up of the results to a computer-simulation of a full-scale commercial hazardous waste incinerator processing ceiling tile contaminated with residual TETS.

  19. Thermal Destruction of TETS: Experiments and Modeling ...

    EPA Pesticide Factsheets

    Symposium Paper In the event of a contamination event involving chemical warfare agents (CWAs) or toxic industrial chemicals (TICs), large quantities of potentially contaminated materials, both indoor and outdoor, may be treated with thermal incineration during the site remediation process. Even if the CWAs or TICs of interest are not particularly thermally stable and might be expected to decompose readily in a high temperature combustion environment, the refractory nature of many materials found inside and outside buildings may present heat transfer challenges in an incineration system depending on how the materials are packaged and fed into the incinerator. This paper reports on a study to examine the thermal decomposition of a banned rodenticide, tetramethylene disulfotetramine (TETS) in a laboratory reactor, analysis of the results using classical reactor design theory, and subsequent scale-up of the results to a computer-simulation of a full-scale commercial hazardous waste incinerator processing ceiling tile contaminated with residual TETS.

  20. Seismic monitoring of precursory fracture signals from a destructive rockfall in the Vorarlberg Alps, Austria

    NASA Astrophysics Data System (ADS)

    Walter, M.; Schwaderer, U.; Joswig, M.

    2012-11-01

    In this study we describe the seismic analysis of precursory patterns of a rockfall in the "Rappenlochschlucht", a gorge located in the Vorarlberg Alps, Austria. The rockfall with an estimated volume of 15 000 m3 occurred on 10 May 2011 (10:48:43 UTC) and destroyed a massive bridge construction. Fortunately, the rockfall did not cause any casualties. A permanent seismic network consisting of three seismic small arrays was installed in July 2009 in 5 km distance to the gorge, at the Heumoes slope, in order to detect and locate slope-related fracture processes within a radius of a few hundred meters. By chance, the rockfall with an estimated equivalent local magnitude of ML,eq = 2.3 was recorded by the seismic network. We observed several smaller rockfall events up to three hours, and 12 fracture signals up to five hours prior to the rockfall. The smaller rockfalls and the fractures were both located in the vicinity of the source area where the main event emerged, applying absolute and relative localization methods. These specific types of fracture signals located near by the gorge "Rappenlochschlucht" have never been observed in almost two years of permanent seismic monitoring. We interpret these fractures with magnitudes between ML = 0.4 and -0.5 as precursory signals of the main rockfall event. The observed fractures and the weaker rockfalls are sequences of initial stress relief within the rock mass and mass transferring processes, respectively, finally causing the destructive main rockfall event. To investigate possible triggers of the destructive rockfall event, several meteorological and hydrological data as well as the local seismicity during that period of time were analyzed and discussed in detail in this study. Unfortunately, no triggering factor of the rockfall event was identified, and remains therefore unknown.

  1. Modeling the Thermal Destruction of Chemical Warfare ...

    EPA Pesticide Factsheets

    Symposium Paper In the event of a terrorist attack with chemical warfare agents (CWAs), large quantities of materials, both indoor and outdoor, may be treated with thermal incineration during the site remediation process. This paper reports on a study to examine the thermal decomposition of surrogate CWAs and formation of decomposition by-products bound in model building materials (in this case, ceiling tile) in a pilot-scale rotary kiln incinerator simulator.

  2. Annual cycle and destruction of Eighteen Degree Water

    NASA Astrophysics Data System (ADS)

    Billheimer, Sam; Talley, Lynne D.

    2016-09-01

    Eighteen Degree Water (EDW), the subtropical mode water of the western North Atlantic, is a voluminous, weakly stratified upper ocean water mass that acts as a subsurface reservoir of heat, nutrients, and CO2. This thick layer persists throughout the year, but nearly half of its volume is dispersed or mixed away, diffusing its properties into the thermocline, from the time it outcrops in winter until it is renewed the following year. CTD observations from Argo profiling floats and acoustically tracked, isothermally bound profiling floats are used to quantify EDW destruction rates and investigate the relevant processes responsible for the large annual cycle of EDW. EDW destruction occurs primarily at the top of the EDW layer, with the highest EDW destruction rates occurring during early summer. Slower, steadier EDW destruction is observed in early winter. EDW destruction is dominated by 1-D vertical diffusion, while mesoscale, along-isopycnal stirring is also significant, explaining approximately 1/3 of the total annual EDW destruction. Destruction via along-isopycnal processes is more prevalent near the Gulf Stream than in the southern Sargasso Sea, due to higher potential vorticity gradients and enhanced mesoscale activity.

  3. Chlorophyll Destruction by the Bisulfite-Oxygen System 1

    PubMed Central

    Peiser, Galen D.; Yang, Shang Fa

    1977-01-01

    Destruction of chlorophyll, as determined by the loss in absorbance at 665 nm, occurred in two in vitro systems in the presence of bisulfite in 76% ethanol. The first system required light and O2 in addition to bisulfite and exhibited an optimum pH of 4. Chlorophyll functioned as a photosensitizer and there was little chlorophyll destruction occurring above pH 5. With 286 μeinsteins m−2 irradiation, approximately 80% of the chlorophyll was destroyed in three minutes. In the second system, chlorophyll destruction in the presence of bisulfite occurred in the dark and required Mn2+, O2, and glycine. Destruction of chlorophyll in this system was much more rapid than in the light system with approximately 70% destruction occurring in two seconds. In both systems, chlorophyll destruction was linked to bisulfite oxidation. The free radical scavengers hydroquinone, butylated hydroxytoluene, 1,2-dihydroxybenzene-3,5-disulfonic acid, and α-tocopherol were effective in inhibiting the destruction of chlorophyll in both systems. The singlet O2 scavengers, 2,5-dimethylfuran and 1,3-diphenylisobenzofuran, were ineffective inhibitors and β-carotene only slightly effective when tested in the light system. The evidence suggests that in these two systems chlorophyll was destroyed by free radicals, probably superoxide radical, which was produced during the aerobic oxidation of bisulfite. PMID:16660075

  4. Rare Events

    DTIC Science & Technology

    2009-10-01

    terrorists are likely to acquire and use WMDs over the next ten years. • Provide means to target areas, entities and persons facilitating adver - sary WMD...complicated and unpredictable to begin with, but also that human adver - saries (unlike physical disasters) will react and adapt to our planning to try to make...virulent vaccine strain (Keim et al., 2001). The latter might not be regarded as a bioterrorism event, even though it caused seven deaths and incited

  5. DESTRUCTION OF INTERSTELLAR DUST IN EVOLVING SUPERNOVA REMNANT SHOCK WAVES

    SciTech Connect

    Slavin, Jonathan D.; Dwek, Eli; Jones, Anthony P.

    2015-04-10

    Supernova generated shock waves are responsible for most of the destruction of dust grains in the interstellar medium (ISM). Calculations of the dust destruction timescale have so far been carried out using plane parallel steady shocks, however, that approximation breaks down when the destruction timescale becomes longer than that for the evolution of the supernova remnant (SNR) shock. In this paper we present new calculations of grain destruction in evolving, radiative SNRs. To facilitate comparison with the previous study by Jones et al., we adopt the same dust properties as in that paper. We find that the efficiencies of grain destruction are most divergent from those for a steady shock when the thermal history of a shocked gas parcel in the SNR differs significantly from that behind a steady shock. This occurs in shocks with velocities ≳200 km s{sup −1} for which the remnant is just beginning to go radiative. Assuming SNRs evolve in a warm phase dominated ISM, we find dust destruction timescales are increased by a factor of ∼2 compared to those of Jones et al., who assumed a hot gas dominated ISM. Recent estimates of supernova rates and ISM mass lead to another factor of ∼3 increase in the destruction timescales, resulting in a silicate grain destruction timescale of ∼2–3 Gyr. These increases, while not able to resolve the problem of the discrepant timescales for silicate grain destruction and creation, are an important step toward understanding the origin and evolution of dust in the ISM.

  6. Coral reef destruction of Small island in 44 years and destructive fishing in Spermonde Archipelago, Indonesia

    NASA Astrophysics Data System (ADS)

    Nurdin, Nurjannah; Komatsu, Teruhisa; Rani, Chair; Supriadi; Fakhriyyah, Sitti; Agus

    2016-11-01

    Coral reefs are among the most diverse and threatened ecosystems on the planet. The most commonly stated for developing coral reef remote sensing techniques is to asses and or to monitor the status of these ecosystems. The study site was selected one of small island in inner zone Spermonde archipelago, Indonesia. We used Landsat MSS, Landsat TM, Landsat ETM, and Landsat OLI data to examine changes in the coral reefs of inner zone island in the Spermonde Archipelago from 1972 to 2016. The image processing are gap fills, atmospheric correction, geometric corrections, image composites, water column corrections, unsupervised classifications, and reclassification. Some of component change detection procedure was applied to define change. The results showed significant changes in 44 years. Disturbed coral reefs are typically characterized by loss of coral cover by increase in the abundance of dead corals and rubble. Local factors such as destructive fishing is direct destruction of inner zone island. While the impact of local threats may be reduced through management action, global threats to coral reefs are likely to increase in severity in the coming years.

  7. [Rapidly destructive hip disease with resultant iliopectineal bursitis].

    PubMed

    Luning, H A; Koster, M N; Coene, L N

    2003-06-28

    A man aged 72 years developed complete destruction of his right hip joint within 12 weeks: 'rapidly destructive hip disease' (RDHD). Analysis of weight loss also revealed iliopectineal bursitis. Nine months after total hip arthroplasty, the patient was free of complaints and the bursitis had disappeared. The cause of RDHD is unclear. Associations have been made with osteonecrosis, chondrocalcinosis and arthropathies of other joints. The destruction of the acetabulum and the femoral head can lead to hydrops in the hip joint and, via a communication between the joint and the iliopectineal bursa, to inflammation of the bursa. This combination of diagnoses has not been described before.

  8. Destructive spondylarthropathy in hemodialyzed patients. A new syndrome.

    PubMed

    Kuntz, D; Naveau, B; Bardin, T; Drueke, T; Treves, R; Dryll, A

    1984-04-01

    Spinal radiologic lesions suggestive of destructive spondylarthropathy were found in 10 patients on long-term hemodialysis. These lesions were characterized by severe narrowing of the intervertebral disc, associated with erosions and geodes of the adjacent vertebral plates without osteophytosis. In 9 of the 10 patients the lesions were located in the cervical spine, and in 1 patient, in the lumbar spine. Microbial spondylitis, degenerative disc disease, and destructive spondylarthropathy of calcium pyrophosphate dihydrate deposition disease were each, in turn, ruled out. The finding of apatite crystals by transmission electron microscopy in 1 disc specimen suggests that these crystals may be associated with destructive vertebral disc lesions in dialysis patients.

  9. Tank 50H Tetraphenylborate Destruction Results

    SciTech Connect

    Peters, T.B.

    2003-10-03

    We conducted several scoping tests with both Tank 50H surrogate materials (KTPB and phenol) as well as with actual Tank 50H solids. These tests examined whether we could destroy the tetraphenylborate in the surrogates or actual Tank 50H material either by use of Fenton's Reagent or by hydrolysis (in Tank 50H conditions at a maximum temperature of 50 degrees C) under a range of conditions. The results of these tests showed that destruction of the solids occurred only under a minority of conditions. (1)Using Fenton's Reagent and KTPB as the Tank 50H surrogate, no reaction occurred at pH ranges greater than 9. (2)Using Fenton's Reagent and phenol as the Tank 50H surrogate, no reaction occurred at a pH of 14. (3)Using Fenton's Reagent and actual Tank 50H slurry, a reaction occurred at a pH of 9.5 in the presence of ECC additives. (4)Using Fenton's Reagent and actual Tank 50H slurry, after a thirty three day period, all attempts at hydrolysis (at pH 14) were too slow to be viable. This happened even in the case of higher temperature (50 degrees C) and added (100 ppm) copper. Tank 50H is scheduled to return to HLW Tank Farm service with capabilities of transferring and receiving salt supernate solutions to and from the Tank Farms and staging feed for the Saltstone Facility. Before returning Tank 50H to Tank Farm service as a non-organic tank, less than 5 kg of TPB must remain in Tank 50H. Recently, camera inspections in Tank 50H revealed two large mounds of solid material, one in the vicinity of the B5 Riser Transfer Pump and the other on the opposite side of the tank. Personnel sampled and analyzed this material to determine its composition. The sample analysis indicated presence of a significant quantity of organics in the solid material. This quantity of organic material exceeds the 5 kg limit for declaring only trace amounts of organic material remain in Tank 50H. Additionally, these large volumes of solids, calculated as approximately 61K gallons, present other

  10. Axon self destruction: new links among SARM1, MAPKs, and NAD+ metabolism

    PubMed Central

    Gerdts, Josiah; Summers, Daniel W.; Milbrandt, Jeffrey; DiAntonio, Aaron

    2015-01-01

    Wallerian axon degeneration is a form of programmed subcellular death that promotes axon breakdown in disease and injury. Active degeneration requires SARM1 and MAP kinases including DLK, while the NAD+ synthetic enzyme NMNAT2 prevents degeneration. New studies reveal that these pathways cooperate in a locally-mediated axon destruction program with NAD+ metabolism playing a central role. Here, we review the biology of Wallerian type axon degeneration and discuss the most recent findings with special emphasis on critical signaling events and their potential as therapeutic targets for axonopathy. PMID:26844829

  11. A ``saddle-node'' bifurcation scenario for birth or destruction of a Smale-Williams solenoid

    NASA Astrophysics Data System (ADS)

    Isaeva, Olga B.; Kuznetsov, Sergey P.; Sataev, Igor R.

    2012-12-01

    Formation or destruction of hyperbolic chaotic attractor under parameter variation is considered with an example represented by Smale-Williams solenoid in stroboscopic Poincaré map of two alternately excited non-autonomous van der Pol oscillators. The transition occupies a narrow but finite parameter interval and progresses in such way that periodic orbits constituting a "skeleton" of the attractor undergo saddle-node bifurcation events involving partner orbits from the attractor and from a non-attracting invariant set, which forms together with its stable manifold a basin boundary of the attractor.

  12. Weapons of Mass Destruction Technology Evaluation and Training Range

    SciTech Connect

    Kevin Larry Young

    2009-05-01

    The Idaho National Laboratory (INL) has a long history for providing technology evaluation and training for military and other federal level Weapons of Mass Destruction (WMD) response agencies. Currently there are many federal organizations and commercial companies developing technologies related to detecting, assessing, mitigating and protecting against hazards associated with a WMD event. Unfortunately, very few locations exist within the United States where WMD response technologies are realistically field tested and evaluated using real chemical, biological, radiological, nuclear and explosive materials. This is particularly true with biological and radiological hazards. Related to this lack of adequate WMD, multi-hazard technology testing capability is the shortage of locations where WMD response teams can train using actual chemical, biological, and radiological material or highly realistic simulates. In response to these technology evaluation and training needs, the INL has assembled a consortium of subject matter experts from existing programs and identified dedicated resources for the purpose of establishing an all-hazards, WMD technology evaluation and training range. The author describes the challenges associated with creating the all-hazards WMD technology evaluation and training range and lists the technical, logistical and financial benefits of an all-hazards technology evaluation and training range. Current resources and capabilities for conducting all-hazard technology evaluation and training at the INL are identified. Existing technology evaluation and training programs at the INL related to radiological, biological and chemical hazards are highlighted, including successes and lessons learned. Finally, remaining gaps in WMD technology evaluation and training capabilities are identified along with recommendations for closing those gaps.

  13. Construction and destruction of some North American cratons

    NASA Astrophysics Data System (ADS)

    Snyder, David B.; Humphreys, Eugene; Pearson, D. Graham

    2017-01-01

    Construction histories of Archean cratons remain poorly understood; their destruction is even less clear because of its rarity, but metasomatic weakening is an essential precursor. By assembling geophysical and geochemical data in 3-D lithosphere models, a clearer understanding of the geometry of major structures within the Rae, Slave and Wyoming cratons of central North America is now possible. Little evidence exists of subducted slab-like geometries similar to modern oceanic lithosphere in these construction histories. Underthrusting and wedging of proto-continental lithosphere is inferred from multiple dipping discontinuities, emphasizing the role of lateral accretion. Archean continental building blocks may resemble the modern lithosphere of oceanic plateau, but they better match the sort of refractory crust expected to have formed at Archean ocean spreading centres. Radiometric dating of mantle xenoliths provides estimates of rock types and ages at depth beneath sparse kimberlite occurrences, and these ages can be correlated to surface rocks. The 3.6-2.6 Ga Rae, Slave and Wyoming cratons stabilized during a granitic bloom at 2.61-2.55 Ga. This stabilization probably represents the final differentiation of early crust into a relatively homogeneous, uniformly thin (35-42 km), tonalite-trondhjemite-granodiorite crust with pyroxenite layers near the Moho atop depleted lithospheric mantle. Peak thermo-tectonic events at 1.86-1.7 Ga broadly metasomatized, mineralized and recrystallized mantle and lower crustal rocks, apparently making mantle peridotite more 'fertile' and more conductive by introducing or concentrating sulfides or graphite at 80-120 km depths. This metasomatism may have also weakened the lithosphere or made it more susceptible to tectonic or chemical erosion. Late Cretaceous flattening of Farallon lithosphere that included the Shatsky Rise conjugate appears to have weakened, eroded and displaced the base of the Wyoming craton below 140-160 km. This

  14. Construction and destruction of some North American cratons

    NASA Astrophysics Data System (ADS)

    Snyder, D. B.; Humphreys, G.

    2015-12-01

    Construction histories of Archean cratons remain poorly understood; their destruction is even less clear because of, by definition, its rarity. By assembling geophysical and geochemical data in 3-D lithosphere models, a clearer understanding of the geometry of major structures within the Rae, Slave and Wyoming cratons of central North America is now possible. Little evidence exists of subducted slabs similar to modern oceanic lithosphere in these construction histories whereas underthrusting and wedging of proto-continental lithosphere is inferred from multiple dipping discontinuities. Archean continental building blocks may resemble the modern lithosphere of Ontong-Java-Hikurangi oceanic plateau. Radiometric dating of xenoliths provides estimates of rock types and ages at depth beneath sparse kimberlite occurrences. These ages can be correlated to surface rocks. The 3.6-2.6 Ga Rae, Slave and Wyoming cratons comprise smaller continental terranes that 'cratonized' during a granitic bloom at 2.61-2.55 ga. Cratonization probably represents the final differentiation of early crust into a relatively homogeneous, uniformly thin (35-42 km), tonalite-trondhjemite-granodiorite crust with pyroxenite layers near the Moho atop depleted lithospheric mantle. Peak thermo-tectonic events at 1.86-1.7 Ga broadly metasomatized, mineralized and recrystallized mantle and lower crustal rocks, apparently making mantle peridotite more 'fertile' and conductive by introducing or concentrating sulfides or graphite throughout the lithosphere at 80-120 km depths. This metasomatism may have also weakened the lithosphere or made it more susceptible to tectonic or chemical erosion. The arrival of the subducted Shatsky Rise conjugate at the Wyoming craton at 65-75 Ma appears to have eroded and displaced the thus weakened base of the craton below 140-160 km. This replaced old refertilized continental mantle with new depleted oceanic mantle. Is this the same craton?

  15. Thermodynamic Profiles of the Destructive June 2012 Derecho

    NASA Astrophysics Data System (ADS)

    Liu, C.; Novakovskaia, E.; Bosse, J.; Ware, R.; Stillman, D.; Sloop, C.; Blanchette, L.; Demoz, B.; Nelson, M.; Cooper, L.; Czarnetzki, A.; Reehorst, A.

    2012-12-01

    The June 2012 mid-Atlantic and Midwest Derecho was one of the most destructive and deadly fast-moving severe thunderstorm events in North American history. The derecho produced wind gusts approaching 100 miles per hour as it traveled more than 600 miles across large sections of the Midwestern United States, the central Appalachians and the Mid-Atlantic States on the afternoon and evening of June 29, 2012 and into the early morning of June 30, 2012. It produced hurricane-like impacts with little warning, resulting in more than 20 deaths, widespread damage and millions of power outages across the entire affected region. We present continuous temperature and moisture profiles observed by microwave radiometers, and derived forecast indices, along the storm path at locations in Iowa, Ohio and Maryland, providing unique perspective on the evolution of this historic storm. For example, an extreme CAPE value of 5,000 J/kg was derived from radiometer observations at Germantown, Maryland ten hours before storm passage, and 80 knot Wind Index (WINDEX) was derived seven hours before passage. The Germantown radiometer is operated as part of the Earth Networks Boundary Layer Network (BLN) for continuous thermodynamic monitoring of the planetary boundary layer up to 30,000 feet. The BLN uses Radiometrics microwave profilers providing continuous temperature and humidity soundings with radiosonde-equivalent observation accuracy, and unique liquid soundings. This case study illustrates the promise for severe storm forecast improvement based on continuous monitoring of temperature and moisture in the boundary layer and above.

  16. Frequency of egg and nestling destruction by female brown-headed cowbirds at grassland nests

    USGS Publications Warehouse

    Granfors, Diane A.; Pietz, Pamela J.; Joyal, Lisa A.

    2001-01-01

    Researchers have suggested that Brown-headed Cowbirds (Molothrus ater) destroy nest contents of potential hosts to induce renesting and thus enhance future opportunities for parasitism. Although cowbird destruction of passerine nests has been witnessed and surmised, few data are available on frequency of those events. We used miniature video-cameras at nests of grassland passerines and documented partial or complete destruction of eggs or nestlings by cowbirds at 7 of 132 nests monitored with cameras. At least three of the seven cases appeared to be attempts to totally destroy the nest contents; those cowbirds did not appear to be motivated by food or an intent to parasitize the nest. Three cases probably were associated with parasitism, but two involved egg removal late in incubation and the third was unusually destructive. Cowbirds were responsible for 24% of egg losses and 5% of nestling losses caused by predators. The importance of cowbirds as an agent of egg and nestling loss undoubtedly varies among sites and years, but it should not be overlooked.

  17. Petrogenesis of Early Cretaceous basaltic lavas from the North China Craton: Implications for cratonic destruction

    NASA Astrophysics Data System (ADS)

    Qian, Sheng-Ping; Ren, Zhong-Yuan; Richard, Wysoczanski; Zhang, Le; Zhang, Yin-Hui; Hong, Lu-Bing; Ding, Xiang-Li; Wu, Ya-Dong

    2017-03-01

    The North China Craton (NCC) is believed to be the best example of cratonic destruction. However, the processes leading to cratonic destruction remain unclear, largely due to a lack of knowledge of the nature of the Mesozoic NCC lithospheric mantle. Here we report new petrological and geochemical data for Early Cretaceous NCC basalts, which provide insights into the nature of the underlying lithospheric mantle. The Early Cretaceous basalts (all tholeiites) show a limited variation in geochemical composition. In contrast, olivine-hosted melt inclusions from these basalts display a wide range in compositional variation and include both alkalic and tholeiitic basaltic compositions. This result provides the direct evidence of the contribution of silica-undersaturated alkali basaltic melts in the petrogenesis of the Early Cretaceous NCC basalts. In addition, the compositions of olivine phenocrysts and reconstructed primary melts indicate that the Early Cretaceous basalts are derived from a mixed peridotite and refertilized peridotite source. The Pb isotopic compositions of melt inclusions in high fugacity of oxygen (fo) olivines combined with trace element characteristics of these basalts reveal that heterogeneous lithospheric mantle sources for Early Cretaceous basalts were metasomatized by carbonate-bearing eclogite-derived melts. The Pb isotopic variations of the melt inclusions and clinopyroxene and plagioclase phenocrysts demonstrate that the mantle-derived magmas were variably contaminated by lower continental crust. We propose that multiple subduction events during the Phanerozoic, combined with mantle-plume activity, likely play a vital role in the generation of the Early Cretaceous voluminous magmatism and cratonic destruction.

  18. Cascades of multisite phosphorylation control Sic1 destruction at the onset of S phase.

    PubMed

    Kõivomägi, Mardo; Valk, Ervin; Venta, Rainis; Iofik, Anna; Lepiku, Martin; Balog, Eva Rose M; Rubin, Seth M; Morgan, David O; Loog, Mart

    2011-10-12

    Multisite phosphorylation of proteins has been proposed to transform a graded protein kinase signal into an ultrasensitive switch-like response. Although many multiphosphorylated targets have been identified, the dynamics and sequence of individual phosphorylation events within the multisite phosphorylation process have never been thoroughly studied. In Saccharomyces cerevisiae, the initiation of S phase is thought to be governed by complexes of Cdk1 and Cln cyclins that phosphorylate six or more sites on the Clb5-Cdk1 inhibitor Sic1, directing it to SCF-mediated destruction. The resulting Sic1-free Clb5-Cdk1 complex triggers S phase. Here, we demonstrate that Sic1 destruction depends on a more complex process in which both Cln2-Cdk1 and Clb5-Cdk1 act in processive multiphosphorylation cascades leading to the phosphorylation of a small number of specific phosphodegrons. The routes of these phosphorylation cascades are shaped by precisely oriented docking interactions mediated by cyclin-specific docking motifs in Sic1 and by Cks1, the phospho-adaptor subunit of Cdk1. Our results indicate that Clb5-Cdk1-dependent phosphorylation generates positive feedback that is required for switch-like Sic1 destruction. Our evidence for a docking network within clusters of phosphorylation sites uncovers a new level of complexity in Cdk1-dependent regulation of cell cycle transitions, and has general implications for the regulation of cellular processes by multisite phosphorylation.

  19. Craton destruction by subduction, collision or plume impingement? Comparisons of some representative cratons in the world

    NASA Astrophysics Data System (ADS)

    Wang, Zhensheng; Kusky, Timothy; Li, Xiaoyong; Wang, Xu; Fu, Jianmin; Yuan, Yuefeng; Zhu, Peimin

    2015-04-01

    The fact that cratonic lithosphere can be destructed has been demonstrated by numerous studies. However, the driving force of craton destruction and its mechanism are still unclear1,2. Subduction, collision and mantle plumes, the most important driving forces for most geological events, may also be responsible for craton destruction. However, their relationship in the destruction process including which of them is the major driving force and how they interact with each other is not understood sufficiently1,2. In this article, the North China Craton, North Atlantic Craton, Tanzania Craton, Wyoming Craton, Kaapvaal Craton, Yangtze Craton, Yilgarn Craton and Superior Craton are used as examples to study their difference and similarities during subduction, collision, or mantle plume impingement. The work is mainly based on comparison of their tectonic history, geophysical data, as well as xenolith chronology. It is suggested that large-scale craton destruction can be influenced by the interaction of subduction, collision and mantle plumes, acting to different degrees in different examples. Mantle plume related thermal action enhances the chemical stratification or layering of subcontinental lithospheric mantle (SCLM), which can form a weak-coupling mid lithosphere discontinuity (MLD) 3,4,5 and a lower denser SCLM below the MLD. Convergence (subduction and collision), especially when associated with slab rollback 6, leads to the regional thinning of the cratonic margin, which is subsequently linked by extension (mantle plume or slab rollback) related discontinuities. Continuous extension-related discontinuities extend upward to the MLD depth and cut off the shearing resistance from adjacent blocks. Next, the lower part of the chemically stratified SCLM in the cratonic interior is decoupled along the weakly coupled MLD and founders into the deep asthenosphere 7. Then the destruction of the rest of the lithosphere can be affected by upwelling related decompression melting

  20. Destructive and non-destructive determination of the transport current density radial distribution: Application to Bi-2212 textured rods

    NASA Astrophysics Data System (ADS)

    Martínez, E.; Natividad, E.; Angurel, L. A.; Navarro, R.; Yang, Y.; Beduz, C.

    2003-03-01

    Destructive and non-destructive methods to estimate the radial distribution of the transport critical current, Jc( r), of long cylindrical superconductors are presented. The non-destructive method is based on the measurement of self-field AC losses as a function of the current amplitude, Q( I0) and takes into account the E- J characteristics of the material. Both methods have been used to derive the Jc( r) profiles of long and thin Bi-2212 rods textured by laser-induced zone melting techniques. The obtained results have been correlated with the microstructure of the samples and their critical temperature.