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. 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.

  4. Geoarchaelogical documentation of a series of destructive events at Montegibbio Roman villa site

    NASA Astrophysics Data System (ADS)

    Borgatti, Lisa; Cervi, Federico; Corsini, Alessandro; Castagnetti, Cristina; Cremonini, Stefano; Guandalini, Francesca; Labate, Donato; Pellegrini, Maurizio; Ronchetti, Francesco

    2010-05-01

    The Italian territory is rich in archaeological heritage, located in hilly, plain or coastal areas. Frequently, it is possible to find only the remains of ancient cultures, villages and sparse houses dating back many centuries. Therefore, no other documentation but the remains themselves can give information about both the existence and the events that eventually determined the end of historical sites, caused either by abandonment or destruction. The causes that can determine the abandonment or the destruction can be various, and may be due to anthropic and/or natural causes, and only in very few cases documents or pictures of these events are preserved. Anthropic causes can be diverse: wrong design and/or building schemes of the structure or of the foundation, wars etc. Natural causes could be variuos as well, and can be related to the environmental context of the site. For example, in mountainous areas the main causes can be landslides, snow avalanches, soil creep affecting the foundations. In plain areas floods are the main process leading to the disruption of hamlets. Along the coast tsunamis are to be considered. Other natural causes could be earthquakes or climate changes. In the Emilian Apennines, near Sassuolo (Modena, Italy), a Roman villa dated from the I century B.C. to the VI century A.D. has been excavated along a gentle slope. The villa can be divided in four different buildings from successive periods. During the first period of life of the villa (I century B.C.-I century A.D.) a destructive event caused the abandonment of this building, whose walls and mosaic floors have been destroyed in a odd way. Which was the cause of this destruction? An earthquake, a human error in construction or a landslide? What makes this question even more interesting is the probable relation of this event with an ancient source (Pliny the Older, Naturalis Historia II, 199) who remembers how in the Modena area a "portentum terrarum" (earthquake) and the collision of two

  5. 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.

  6. Characterization of ignition overpressure using band limited temporal moments

    SciTech Connect

    Cap, J.S.

    1994-11-01

    The ignition overpressure event is a transient vibroacoustic environment which occurs when a missile is launched. The environment is often too short to obtain a good estimate of the event using Power Spectral Densities, and Shock Response Spectra are limited in their ability to fully describe the nature of the environment. Sandia National Laboratories has employed band limited temporal moments in an effort to characterize the acceleration response of the components and payloads to the ignition overpressure environment and the related laboratory test inputs. The purpose of this paper will be to show the results of that study.

  7. 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

  8. 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.

  9. 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.

  10. 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)

  11. 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.

  12. Geology and diagenetic history of overpressured sandstone reservoirs, Venture Gas field, offshore Nova Scotia, Canada

    SciTech Connect

    Jansa, L.F. Dalhousie Univ., Halifax, Nova Scotia ); Urrea V.H.N. )

    1990-10-01

    Deep exploratory wells in the Scotian Basin, offshore Nova Scotia, Canada, have encountered overpressured formations with pressures 1.9 {times} the normal hydrostatic gradient. The overpressures occur over an area of approximately 10,000 km{sup 2}. In the Venture field, the abnormal pressures are confined below a depth of 4,500 m and are associated with Upper Jurassic-Lower Cretaceous gas- and condensate-bearing sandstone reservoirs. The overpressures occur within normally compacted shales containing numerous overpressured sandstone reservoir beds. The development of overpressures, seals, and secondary reservoirs are all diagenetically driven. Three secondary porosity depth levels, which top at 2,500 m (65C), 3,700 m (95C), and 4,600 m (130C), correlate with major steps in the organic matter maturation in the basin. Secondary porosity is initially achieved by aluminosilicate dissolution, with ferroan sparry calcite cement dissolution dominating below 4,000 m. Porosity enhancement and preservation is not the result of a single diagenetic event but instead the result of a series of diagenetic events that overlapped in time. Formation of dynamic diagenetic barriers within the zone of peak gas generation helps retard the diffusive migration of hydrocarbons and other fluids expelled during shale diagenesis resulting in pressure build up. The preservation of up to 32% porosity under 500-1,000 atm of pressure could not be achieved without simultaneous pressuring of developing voids. Significant for hydrocarbon exploration is that Venture-type diagenetic overpressures are not associated with undercompacted sediments and, hence, they cannot be predicted from compaction trends during drilling. Petrographic diagenetic, and lithofacies studies can be instrumental in predicting potential areas of deep subsurface secondary reservoirs dependent.

  13. Data acquisition from blast overpressure trials

    NASA Astrophysics Data System (ADS)

    Kirk, D. R.

    1993-03-01

    A Macintosh computer has been used to acquire data from blast overpressure trials on various weapons. The computer is connected to a multiple channel FM data recorder via a MacSCS1488 bus controller, allowing the computer to control the recorder and to acquire data from it through an analog to digital converter. Detailed instructions are given for connecting the hardware and operating the software involved.

  14. 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.

  15. 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.

  16. Earthquake Rupturing in Fluid-Overpressured Crust: How Common?

    NASA Astrophysics Data System (ADS)

    Sibson, Richard H.

    2014-11-01

    Whether or not ruptures nucleate in fluid-overpressured crust ( λ v = P f/ σ v > 0.4) is important because pore-fluids overpressured above hydrostatic lower fault frictional strength and may also vary through the earthquake cycle, acting as an independent variable affecting fault failure. Containment of fluid overpressure is precarious because pressure-dependent activation of faults and fractures allows drainage from overpressured portions of the crust. Discharge of fluids through activated fault-fracture permeability (fault-valve action) decreases overpressure so that subsequent failure depends on the cycling of both overpressure and frictional strength as well as tectonic stress. Geometric and mechanical considerations suggest that fluid overpressures are more likely to develop and be sustained in compressional/transpressional regimes as opposed to extensional/transtensional tectonic settings. On the basis of geophysical observations and force-balance analyses, subduction interface shear zones appear to be strongly but variably overpressured to near-lithostatic levels ( λ v > 0.9) over the full depth range of seismogenic megathrusts. Strong overpressuring at seismogenic depths is also documented in active fold-thrust belts and in areas of ongoing compressional inversion (e.g., northern Honshu) where inherited normal faults are reactivated as steep reverse faults, requiring near-lithostatic overpressures ( λ v → 1.0) at depths of rupture initiation. Evidence for overpressuring around strike-slip faults is less clear but tends to be strongest in areas of transpression. In areas of extensional tectonics coincident with particularly high fluid discharge, there is some evidence of overpressuring concentrated towards the base of the seismogenic zone. In general, because of the limited resolution of geophysical techniques, it is easier to make the case for rupture propagation through overpressured crust than to make a definitive case for the direct involvement of

  17. 49 CFR 192.195 - Protection against accidental overpressuring.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. Fluid Overpressure and Connections to Seismicity, Cascadia Tertiary Accretionary Prism, Olympic Peninsula

    NASA Astrophysics Data System (ADS)

    Rotman, H.; Mattinson, C. G.

    2010-12-01

    Metamorphic dehydration reactions and fluid movement in accretionary prisms have been linked to the recently discovered episodic tremor and slip (ETS) earthquake events along subduction zones, but prior studies lack the detail to effectively test the hypothesis that fluid flow triggers ETS events. I conducted field work along a 52.5 km transect on the Olympic Peninsula metasedimentary accretionary prism of the Cascadia subduction zone, and collected approximately 40 representative samples of sandstone and mudrock that were buried to 6-15 km. This depth range intersects the 10-50 km depth range of ETS events. My objectives are to quantify the water flow recorded in rocks of the Olympic Peninsula via petrographic, whole rock, and isotopic analyses to test the prediction that water release increases at ~10 km depth, creating fluid overpressure needed to trigger seismicity. I calculated that on the Olympic Peninsula 1 km3 of 50% sandstone and 50% mudrock loses ~105 kg H2O/yr during burial from 6-14 km depth, comparable to the values expected from large-scale fluid budget models. Quartz veins that compose 0.5-1% of the Obstruction Peak site (~14 km burial depth) are important records of fluid flow quantity and origin. δ18O values of +11.8‰ to +15.2‰ indicate that vein H2O originated from metamorphic reactions. Flow recorded by 1 km3 of rock containing 0.5-1% quartz veins is >106 kg H2O/yr, comparable to the values 2 × 107 to 2 × 108 kg H2O/yr modeled at compositionally similar subduction zones to produce fluid overpressure conditions. I observed fibrous quartz veins, which also indicate fluid overpressure conditions were reached and support my H2O flow estimates. Therefore, Olympic Peninsula rocks at depths of ~10-14 km record dehydration and fluid overpressure large enough to trigger subduction zone seismicity.

  4. The October 15, 1997 Punitaqui earthquake (Mw=7.1): a destructive event within the subducting Nazca plate in central Chile

    NASA Astrophysics Data System (ADS)

    Pardo, Mario; Comte, Diana; Monfret, Tony; Boroschek, Rubén; Astroza, Maximiliano

    2002-02-01

    The 1943 Illapel seismic gap, central Chile (30-32°S), was partially reactivated in 1997-1998 by two distinct seismic clusters. On July 1997, a swarm of offshore earthquakes occurred on the northern part of the gap, along the coupled zone between Nazca and South American plates. Most of the focal mechanisms computed for these earthquakes show thrust faulting solutions. The July 1997 swarm was followed on October 15, 1997 by the Punitaqui main event (Mw=7.1), which destroyed the majority of adobe constructions in Punitaqui village and its environs. The main event focal mechanism indicates normal faulting with the more vertical plane considered as the active fault. This event is located inland at 68-km depth and it is assumed to be within the oceanic subducted plate, as are most of the more destructive Chilean seismic events. Aftershocks occurred mainly to the north of the Punitaqui mainshock location, in the central-eastern part of the Illapel seismic gap, but at shallower depths, with the two largest showing thrust focal mechanisms. The seismicity since 1964 has been relocated with a master event technique and a Joint Hypocenter Determination (JHD) algorithm, using teleseismic and regional data, along with aftershock data recorded by a temporary local seismic network and strong motion stations. These data show that the 1997 seismic clusters occurred at zones within the Illapel gap where low seismicity was observed during the considered time period. The analysis of P and T axis directions along the subduction zone, using the Harvard Centroid Moment Tensor solutions since 1977, shows that the oceanic slab is in a downdip extensional regime. In contrast, the Punitaqui mainshock is related to compression resulting from the flexure of the oceanic plate, which becomes subhorizontal at depths of about 100 km. Analog strong motion data of the Punitaqui main event show that the greatest accelerations are on the horizontal components. The highest amplitude spectra of the

  5. 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.

  6. Friction, overpressure and fault normal compression

    SciTech Connect

    Byerlee, J. )

    1990-11-01

    More than twenty-five years ago Miller and Low reported the existence of a threshold pore pressure gradient below which water would not flow through clay. Recent experimental observations of the shear strength of structured water on biotite surfaces have provided a physical basis for understanding this threshold gradient. The existence of this phenomenon has profound implications for the rheological properties of mature fault zones, such as the San Andreas, that contain large thickness of fault gouge. For example, a clay-filled fault zone about 1 km wide at the base of the surface could support core fluid pressure equal to the maximum principal stress over the entire seismogenic zone. As a result, the fault would have near-zero strength and the maximum principal stress measured on the flanks of the fault, would be oriented normal to the fault surface. Another consequence of the threshold gradient is that normal hydrostatic fluid pressures outside the fault zone could coexist with near-lithostatic fluid pressures in the interior of the fault zone without the need for continual replenishment of the overpressured fluid. In addition, the pore pressure at any point should never exceed the local minimum principal stress so that hydrofracture will not occur.

  7. 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.

  8. Manifestations of the 15.11.2006 Kuril Tsunami Consequences on the Central Kuril Islands: the Reconstruction Events of the Destruction of Soil and Coastal Vegetation.

    NASA Astrophysics Data System (ADS)

    Levin, B.; Kopanina, A.; Ivelskaya, T.; Sasorova, E.

    2007-12-01

    The investigation of the Central Kuril Islands (Simushir, Urup, Ketoy) coast was performance by the field survey for the Institute of Marine Geology and Geophysics FEB RAS (Yuzhno-Sakhalinsk) on the vessel "Iskatel-4" to be able find different deposits of the devastating tsunami waves influence on soil and vegetation. There were average run-up heights and inundation areas (tsunami flooding zones): h=6-9 m and 40-60 m (Ketoy); h=7-19 m and 80-300 m (Simushir). The field observation showed destruction of the soil layer. The estimation of water stream velocity for the hydraulic destruction of rocks enabled to receive velocity average mean for the water stream during tsunami dynamic inundation which may be in interval of velocities near 30 -50 m/sec. Field observations of coastal plants in tsunami inundation zones on Urup, Simushir and Ketoy Islands enabled us to recognize the character of destructive influence of tsunami waves to plant structure and essential signs of micro-phytocenoses for ecotopes at different distances from the coastline. Various plant species and vital morphes were found to indicate different reaction on sea waves. The investigation results showed that selected plant species demonstrate the strong response to tsunami wave inundation. We found that the most sensitive species to mechanical and physical- chemical tsunami impact are: Pinus pumila (Pall.) Regel and Phyllodoce aleutica (Spreng.) A. Heller. The character of plant damage shows in breaking of skeletal axes, infringement of root systems, and leaf dying. These findings allow us to use the species as effective indicators of tsunami flooding zone and estimation of tsunami run-up heights. Fulfilled analyzes let us to reconstruct possible events when tsunami hits to coast with specific shore morphology. The wave front at the slightly sloping coast (from coastline to first terrace) is characterized by uniform growth of water level when water moves away soil material (no more 2-3 cm) and micro

  9. Coupled Eulerian/Lagrangian Simulation for Overpressure Structural Response

    NASA Astrophysics Data System (ADS)

    Lloyd, Andrew; Pan, Hua; Miller, David; Cogar, John

    2011-06-01

    Accurately modeling blast dynamics is critical in the assessment of structures subjected to blast loading. The current industry standard for modeling blast effects in Lagrangian based Finite Element simulations is CONWEP; tabulated pressure data taken directly from blast events. CONWEP is limited, however, and may not always be physically representative of the blast/structural interaction that occurs in the field. Eulerian hydrocodes provide advantages over CONWEP in that they can capture shock front interaction and model blast surface interfaces with fidelity due to the presence of the working fluid. Eulerian codes, however, break down over larger time scales; whereas, Lagrangian modeling allows for discrete finite elements with definable boundary interfaces that can be tracked out to longer time scales. Hence, a hybrid approach that couples the Eulerian blast modeling with Lagrangian system dynamics is necessary. The objective of this paper is to demonstrate improvements in overpressure structural response modeling using a Coupled Eulerian/Lagrangian algorithm implemented in VelodyneTM. Velodyne results using the Coupled Eulerian/Lagrangian algorithm are compared to results from Eulerian hydrocode simulations and Velodyne simulations using the CONWEP algorithm.

  10. Coupled Euler-La Grange simulation for overpressure structural response

    NASA Astrophysics Data System (ADS)

    Lloyd, Andrew N.; Miller, David K.; Pan, Hua; Cogar, John

    2012-03-01

    Accurately modeling blast dynamics is critical in the assessment of structures subjected to blast loading. The current industry standard for modeling blast effects in La Grange based finite element simulations is CONWEP; tabulated pressure data taken directly from blast events. CONWEP is limited, however, and may not always be physically representative of the blast/structural interaction that occurs in the field. Euler hydrocodes provide advantages over CONWEP in that they can capture shock front interaction and model blast surface interfaces with fidelity due to the presence of the working fluid. Euler codes, however, break down over larger time scales due to advection; whereas, Lagrange modeling allows for discrete finite elements with definable boundary interfaces that can be tracked out to longer time scales. Hence, a hybrid approach that couples the Euler blast modeling with La Grange system dynamics is necessary. The objective of this paper is to demonstrate improvements for high explosive overpressure structural response modeling specifically with respect COMP-B high explosive acting upon blasted fragments using a Coupled Euler-La Grange algorithm implemented in VelodyneTM. Velodyne results using the Coupled Euler-La Grange algorithm are compared to results from an Euler hydrocode simulation (CTH) and Velodyne simulations using the CONWEP algorithm.

  11. An analytical model for gas overpressure in slug-driven explosions: Insights into Strombolian volcanic eruptions

    NASA Astrophysics Data System (ADS)

    Del Bello, Elisabetta; Llewellin, Edward W.; Taddeucci, Jacopo; Scarlato, Piergiorgio; Lane, Steve J.

    2012-02-01

    Strombolian eruptions, common at basaltic volcanoes, are mildly explosive events that are driven by a large bubble of magmatic gas (a slug) rising up the conduit and bursting at the surface. Gas overpressure within the bursting slug governs explosion dynamics and vigor and is the main factor controlling associated acoustic and seismic signals. We present a theoretical investigation of slug overpressure based on magma-static and geometric considerations and develop a set of equations that can be used to calculate the overpressure in a slug when it bursts, slug length at burst, and the depth at which the burst process begins. We find that burst overpressure is controlled by two dimensionless parameters: V', which represents the amount of gas in the slug, and A', which represents the thickness of the film of magma that falls around the rising slug. Burst overpressure increases nonlinearly as V' and A' increase. We consider two eruptive scenarios: (1) the "standard model," in which magma remains confined to the vent during slug expansion, and (2) the "overflow model," in which slug expansion is associated with lava effusion, as occasionally observed in the field. We find that slug overpressure is higher for the overflow model by a factor of 1.2-2.4. Applying our model to typical Strombolian eruptions at Stromboli, we find that the transition from passive degassing to explosive bursting occurs for slugs with volume >24-230 m3, depending on magma viscosity and conduit diameter, and that at burst, a typical Strombolian slug (with a volume of 100-1000 m3) has an internal gas pressure of 1-5 bars and a length of 13-120 m. We compare model predictions with field data from Stromboli for low-energy "puffers," mildly explosive Strombolian eruptions, and the violently explosive 5 April 2003 paroxysm. We find that model predictions are consistent with field observations across this broad spectrum of eruptive styles, suggesting a common slug-driven mechanism; we propose that

  12. Precarious Containment of Overpressured Fluids in Subduction Settings

    NASA Astrophysics Data System (ADS)

    Sibson, R. H.

    2014-12-01

    Subduction forearcs are critically organized systems whose metastable state is governed by the configuration of boundary stresses and the internal distribution of fluid-pressure in pore/fracture space. In particular, seismogenic megathrusts lying within subduction interface shear zones (SISZ) appear overpressured to near-lithostatic values (i.e. λv = Pf/σv → 1.0) with substantial fluid repositories (<4% porosity) likely in tabular zones of non-volcanic tremor (NVT) defining the base of some megathrusts. Containment of overpressure is precarious because activation of brittle fault-fracture systems allows escape of overpressured fluids. This leads to a critical interdependence of differential stress and fluid-overpressure with overpressures more easily sustained in compressional as opposed to extensional stress regimes. Overpressures within SISZ are thus susceptible to abrupt stress changes and subsidiary fracturing that may occur locally around rupture heterogeneities or, on a broader scale, when total shear stress relief and stress field switching occurs along a megathrust, as occurred during the 2011 Mw9.0 Tohoku-oki earthquake. Massive fluid loss from a SISZ following megathrust rupture has been inferred from observed changes in the velocity structure of a fore-arc hangingwall. Paleodischarge sites in subduction fore-arcs exists in the form of diapiric roots to mud volcanoes and hydrothermal vein swarms. In some exhumed forearcs, extensive belts of Au-Quartz mineralization (orogenic gold) are plausibly related to episodic fluid redistribution from the subduction interface. Fluid loss from SISZ locally raises frictional strength along the megathrust, forming strength asperities. Subsequent failure of such 'drainage asperities' is then governed by the reaccumulation of fluid overpressure as well as shear stress within the SISZ. Populations of drainage asperities at various stages of overpressure restoration are likely along subduction interfaces.

  13. Overpressure during indentation and the origin of ultra-high-pressure rocks in the Alps

    NASA Astrophysics Data System (ADS)

    Regenauer-Lieb, K.; Rosenbaum, G.; Weinberg, R. F.; Manatschal, G.

    2012-12-01

    Ultra-high-pressure (UHP) rocks in the European Alps, which record metamorphic pressures of >30 kbar, are commonly interpreted to indicate burial of crustal rocks to depths of >100 km. Tectonic models that explain such high pressures assume that rocks were taken to great depths by subduction of an oceanic Tethyan lithosphere and were subsequently decompressed during exhumation. The paradox of Alpine geodynamics is that plate reconstructions and geological data indicate that Alpine oceans were limited to narrow basins that never developed into true oceanic domains. Therefore, these basins would have been unable of generating mature subduction zones capable of driving events of deep burial and exhumation, which are used to explain the origin of the UHP rocks. Here we show an alternative model, whereby UHP metamorphism results from the build up of overpressure during indentation. We consider the concept of contained plasticity in contact mechanics (Johnson, K.L., Contact Mechanics. 2nd ed. 1989, Cambridge: Cambridge University Press. 452.), and demonstrate the possibility of significant overpressures during continental collision and associated vertical thickening. The highest overpressures are reached when the collisional orogeny shows significant strike-slip faulting (see Figure 1). Our results resolve the paradox of the origin of UHP rocks in the Alps, showing that their metamorphism could have occurred at considerably shallower depths (by more than a factor of 3-4) than previously suggested. Figure 1 shows over/underpressures calculated from Sibson's approach (Nature 249, 542-544,1974). Our new contribution is to show that tectonic overpressures can be boosted significantly in strike slip faultiing.

  14. Thrust wedges and fluid overpressures: Sandbox models involving pore fluids

    NASA Astrophysics Data System (ADS)

    Mourgues, R.; Cobbold, P. R.

    2006-05-01

    The well-known model for the critical taper of an accretionary wedge includes overpressure as a first-order parameter. Fluid overpressures reduce frictional resistance at the base of a wedge but they also act as body forces on all material particles of the wedge, in addition to that of gravity. By means of sandbox modeling, many workers have tried to verify the predictions of the critical taper model, but few of them have so far incorporated true fluid pressures. We have used scaled experiments, in which compressed air flows through sand packs, so as to model the deformation of overpressured wedges. A new apparatus provides for a horizontally varying fluid pressure, for example, a linear variation, as in the critical taper model. We have done three series of experiments, involving horizontal shortening of homogeneous or multilayered sand models for various gradients of fluid pressure. As predicted by the critical taper model, the apical angle of the resulting wedge depends on the overpressure gradient. In homogeneous sand at a high overpressure gradient, deformation becomes diffuse and looks ductile. In multilayered models, detachments form beneath layers of low permeability, so that thrusts propagate rapidly toward the undeformed foreland. The efficiency of a detachment and its ability to propagate depend not only on the fluid pressure but also on the permeability ratios between the various layers.

  15. 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.

  16. Does Earthquake Rupturing Initiate in Fluid-Overpressured Crust? - The Case for Scientific Drilling in NE Honshu

    NASA Astrophysics Data System (ADS)

    Sibson, R. H.

    2009-12-01

    Inland earthquakes in Japan arise from rupturing within an upper crustal seismogenic zone that is typically 10-20 km deep. Because such events may occur in close proximity to cities or critical facilities, giving rise to particularly intense ground motions, they contribute significantly to the aggregate seismic hazard. Since 2003, five strong crustal earthquakes (6.3 < M < 6.9) have ruptured steep reverse faults (dips > 45°) both west and east of the Ou Backbone Range hosting the volcanic front in NE Honshu. The earthquakes generally nucleated within the lower seismogenic zone at depths of 5 - 15 km. Several earlier events in the region (e.g. 1964 M7.5 Niigata earthquake) are of similar character. These steep reverse ruptures appear to be part of the ongoing compressional inversion of Miocene rift basins associated with arc-normal shortening that began at c. 3.5 Ma. Hazard from such compressional inversion earthquakes is difficult to assess because potential seismogenic faults (often with low net displacement) tend to be blanketed by post-rift deposition within sedimentary basins (e.g. the 2004 M6.6 Mid-Niigata and M6.6 Niigata-Chuetsu earthquake sequences). The compressional regime of NE Honshu is an optimal setting for ‘holding-in’ fluid overpressure. Frictional mechanics suggests that reactivation of inherited normal faults as steep reverse faults requires pore-fluid pressure elevated above hydrostatic to near-lithostatic pressures at the depth of rupture initiation. Oil-field drilling has shown that aqueous overpressures above hydrostatic exist at depths > 2-3 km in the Niigata sedimentary basin which has hosted several of the rupture sequences. In addition, local geophysical anomalies (high electrical conductivity, seismic low velocities, bright-spot S-wave reflectors, Vp/Vs) in NE Honshu point to heterogeneous fluid overpressuring in the vicinity of the active faults in the lower seismogenic zone. Whether or not earthquake ruptures initiate in fluid

  17. Overpressured fluid imaging from focal mechanisms during the 2003-2004 Ubaye seismic swarm (Southern-Alps, France)

    NASA Astrophysics Data System (ADS)

    Leclère, H.; Daniel, G.; Fabbri, O.; Cappa, F.

    2012-04-01

    The development of fluid pressure is thought to play a major role in earthquake triggering and in fault reactivation (Nur & Booker, 1972; Sibson, 1985; Miller et al., 2004; Hainzl et al., 2006; Cappa et al., 2009; Terakawa et al., 2010) In this study, we present an analysis of the potential key role of fluid pressure on the triggering of the 2003-2004 Ubaye (France) seismic swarm. Our aim is to provide a better understanding of fluid pressure build-up along fault zones and its influence on earthquake triggering. More than 16,000 microseismic events were detected during the Ubaye swarm. This swarm occurred over an area located between the Argentera-Mercantour and the Pelvoux crystalline massifs, below the Embrunais-Ubaye nappes (Jenatton et al., 2007). Hypocentral depths were comprised between 3 and 8 km and the spatial distribution of hypocenters was parallel to the azimuth of major regional NW-SE faults. This suggests that seismic ruptures reactivated a preexisting fault zone in the crystalline basement (Leclère et al., in press). Based on Mohr-Coulomb theory and a fault zone orientation of the seismic swarm computed by Daniel et al. (2011), we estimate the overpressured fluid required to reactivate this fault to be between 7 and 26 MPa (Leclère et al., in press). This result is in good agreement with a previous study by Daniel et al. (2011). We propose a mechanism for the development of overpressured fluid conditions that accounts for the presence of thermal springs, fault zone compaction processes and hydraulic barriers (Leclère et al., in press). In a further step, we analyze an extended focal mechanism dataset and we focus on overpressured fluid conditions required to reactivate individual fault planes related to each focal mechanism. We then investigate the correlation between changes in overpressured fluid conditions and changes in the seismicity rate. We also discuss the spatial heterogeneity of overpressured fluid conditions.

  18. Controls on maximum fluid overpressure defining conditions for mesozonal mineralisation

    NASA Astrophysics Data System (ADS)

    Sibson, Richard H.

    2004-06-01

    The mesozonal environment for mineralisation (˜10±5 km depth) occurs towards the base of the seismogenic zone in the upper continental crust which, in areas of strong fluid release, acts as a stressed elastic lid containing overpressured hydrothermal fluids derived from metamorphic dehydration at depth. Au-quartz lodes in this environment are hosted by fault-fracture meshes comprising dilatant extensional and extensional-shear fractures interlinked by low-displacement faults. They form in a range of tectonic regimes but are most extensively developed in compressional/transpressional settings. A brittle failure mode plot contrasting compressional and extensional stress regimes demonstrates that: (i) high fluid overpressures are easier to sustain in compressional regimes that also allow the highest amplitude fluid-pressure cycling; (ii) dilatant mesh structures serve as high-permeability conduits only under high fluid-pressure and low differential stress in the absence of through-going cohesionless faults that are well-oriented for reactivation; and, (iii) the critical interdependence of differential stress and sustainable overpressure ensures that changes in stress state are accompanied by fluid redistribution. The specialised circumstances allowing high-flux flow of overpressured fluids are generally short-lived and are terminated by the formation of through-going, favourably oriented faults.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. Methane generation in subduction zones: A cause for fluid overpressures?

    NASA Astrophysics Data System (ADS)

    Raimbourg, Hugues; Disnar, Jean-Robert; Thiery, Regis; Ramboz, Claire; Yamaguchi, Asuka; Kimura, Gaku

    2013-04-01

    The nature of the fluids involved in the deep plate interface in subduction zones is difficult to constrain, as it incorporates many potential sources (sea water trapped in pores, water from dehydration reactions, fluid from the depths of the subduction channel or from the slab). Using Raman analysis of fluid inclusions in quartz veins from the deep domains of the Shimanto paleo-accretionary complex, Japan, we first show that at temperatures of ~250°C, the fluid is a mixture of water and methane, in agreement with literature on similar terranes. In most of the studied area, we could observe only one, water-rich, kind of inclusion, while in a restricted region a second, methane-rich, kind of inclusion was also present, suggesting in the first case the circulation at depth of a single fluid and in the second case the coexistence of two fluid phases. We used then isochores of the methane-rich fluid inclusions to constrain the paleo- fluid pressure. In the present case, methane-rich inclusions are distributed as planes, i.e. along healed microcracks, hence they provide a record of the conditions that prevailed during a short period of time. Within a single plane of inclusions, homogeneization temperatures of the methane phase show large variations between inclusions, which we interpret as the record of large and rapid variations in fluid pressure. To account for this diversity in the fluid state (single- vs. two-phased) as well as for the rapid variations in pressure, we developed a model of methane generation by thermal cracking of organic matter during burial. In spite of the low average organic matter content of subducted sediments, the porosity, hence the water content of deep sediments is sufficiently low for the oversaturation of the water in methane, hence unmixing of a free, methane-rich phase, to be a realistic scenario. Predicted overpressures resulting from rapid unmixing of methane can be significant with respect to ambient fluid pressure and constitute

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. Witnessing Extrasolar Asteroid Destruction?

    NASA Astrophysics Data System (ADS)

    Xu, Siyi; Jura, Michael; Su, Kate; Meng, Huan

    2014-11-01

    40 white dwarfs with excess infrared radiation due to a circumstellar dust disk from tidally disrupted asteroids have been identified. Recently, we identified one dusty white dwarf whose infrared fluxes have been increasing since May 2014. Very likely, it is caused by a recent tidal disruption event of extrasolar asteroid. We propose DDT to follow it up in a timely manner because the flare could dissipate very soon. This proposal provides a unique opportunity to study the destruction of an extrasolar asteroid.

  9. Crustal Dehydration and Overpressure Development on the San Andreas Fault

    NASA Astrophysics Data System (ADS)

    Fulton, P. M.; Saffer, D. M.; Bekins, B. A.

    2005-12-01

    Previous authors have hypothesized that the apparent weakness of the San Andreas Fault may be explained by fluid overpressures resulting from the combination of crustal dehydration of the Franciscan mélange and the presence of a low-permeability serpentinite cap at its geologic contact with the Great Valley Sequence. We previously evaluated this hypothesis by calculating the spatial and temporal distribution of fluid sources and then incorporating these sources in 2-D models of fluid flow and heat transport perpendicular to the fault. We have refined our fluid source calculations using theoretical values of whole-rock H2O content and PT histories for the Franciscan crust in the wake of northward migration of the Mendocino Triple Junction (MTJ). The sources obtained reach peak values of 10-16 s-1. The coupled fluid flow and heat transport model now accommodates large-scale crustal deformation in a more rigorous manner by constructing new model grids after each change in crustal thickness. In the models, we assign permeability of the crust as a function of depth. A 500-m-thick, low-permeability serpentinite body (k=10-20 m-2) extends across the eastern half of the 50 km-wide model domain at a depth of 2 km. In addition, various model simulations include fault structures centered in the model domain such as: a 500 m wide low permeability fault barrier (kfault = kcrust/100), a fault conduit (kfault = kcrust x 100), a barrier within a 1.5 km wide conduit damage zone, and a conduit plugged by a 3 km-thick and 2 km-wide barrier simulating a broad, clay-rich, low-permeability zone, at shallow depth within the fault system, which is one possible interpretation of seismic and electromagnetic data. We also test additional scenarios to evaluate sensitivity to changes in model permeability. Model results show overpressures, as large as 162% of hydrostatic (62% of lithostatic) for the model with a serpentinite cap and fault barrier, develop within 4 Ma of Mendocino Triple

  10. Fluid Overpressuring in the Lower Seismogenic Zone - How Widespread?

    NASA Astrophysics Data System (ADS)

    Sibson, R.

    2008-12-01

    Microseismic activity typically occupies the top 10-20 km of actively deforming continental crust but shallows in areas of active plutonism and geothermal activity and deepens in areas of rapid crustal convergence. Depending on composition, the base of this crustal microseismic zone is defined by low- to mid-greenschist facies metamorphic conditions at temperatures between 350 and 450 degrees. Larger ruptures (M>6) tend to nucleate in the lower half of this microseismic zone, or at its base. Fault frictional strength within the seismogenic zone likely represents a significant component of integrated lithospheric strength but is critically affected by variations in the ratio of fluid to overburden pressure (λv = Pf/σv). If fracture permeability in seismogenic crust is too high to sustain fluid overpressures (λv > 0.4), bulk strength is determined by optimally oriented faults with 'Byerlee' friction under hydrostatic fluid-pressure (λv ~ 0.4). However, high solute levels in hydrothermal fluids may 'self-seal' fractures in active flow systems. In addition, tectonic stress exerts strong controls on structural permeability and the containment of fluid overpressure in the crust, overpressures being more easily generated and sustained in compressional as opposed to extensional settings. These concepts are explored by comparing inferred fluid-pressure states within the actively extending Taupo Rift system, New Zealand with the compressional regime hosting the volcanic arc in NE Honshu, Japan. Both regions are magmatically active and occupy the hangingwalls of active subduction zones where magmatic fluids are entering the crust. Convective circulation of predominantly meteoric water under hot/cold hydrostatic pressure appears to extend throughout the 7-8 km deep seismogenic layer within the Taupo Rift system. By contrast, in the compressional setting of NE Honshu where crustal shortening and thickening is likely accompanied by prograde metamorphism and dewatering, a

  11. Global variation of sonic boom overpressure due to seasonal changes in atmosphere

    NASA Astrophysics Data System (ADS)

    Yamashita, Hiroshi; Obayashi, Shigeru

    2012-09-01

    Global variation of sonic boom overpressures with the realistic atmospheric gradients was discussed. The atmospheric gradients were estimated by upper-air observational radiosonde data and a simple N-wave was extrapolated through all seasonal atmospheric gradients without winds around the world. Results demonstrated that sonic boom overpressure varies widely with season and geographic position compared to that of the standard atmospheric condition. The results also showed the tendencies of the global variation in overpressure.

  12. 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. PMID:25405432

  13. 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. PMID:25781067

  14. 46 CFR 39.20-11 - Vapor overpressure and vacuum protection-TB/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Vapor overpressure and vacuum protection-TB/ALL. 39.20... SYSTEMS Design and Equipment § 39.20-11 Vapor overpressure and vacuum protection—TB/ALL. (a) The cargo... psig; (3) Prevent a vacuum in the cargo tank vapor space, whether generated by withdrawal of cargo...

  15. 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. PMID:24247639

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. A self-destruction game.

    PubMed

    Raczynski, Stanislaw

    2006-10-01

    A simple model of a self-destructing society is presented. It can be interpreted as a game with two players: the society and its sub-set which tends to destroy the whole society, as well as itself. The main factor taken into account in the model is the progress of science and technology which provides the destruction tools (new weapons and killing techniques), as well as tools the society can use to defend itself. The modeling and simulation tool is discrete-event and can be treated as agent-oriented, though the agent capabilities are rather simple. The simulation experiments show that, in the near future, this progress will become extremely dangerous, and it may result in the total destruction of mankind. For the longer time period, however, the conclusion is not so pessimistic. If the society survives during a certain time interval, then the probability of survival becomes greater for a longer time span. PMID:16884653

  1. An investigation on cracking of glasspanes due to air overpressure

    SciTech Connect

    Prakash, A.J.; Nabiullah, M.; Dhar, B.B.

    1994-12-31

    The study is an approach made in simulating air overpressures induced by surface blasting from those produced during gallery blasting in the laboratory, and experiments conducted on a portable window with a view to establish the sound pressure level (SPL) for cracking of window glasspanes. Eight different strengths of commercial explosives normally being used in blasting practices, were fired in the cannon of explosive gallery. SPL recorded on the seventh channel of a digital seismograph (SINCO-6) provided with FFT facility, are compared with those produced from surface blastings conducted in different Indian geomining conditions. They are found to be similar in frequency characteristics. A model of portable window provided with two replaceable glass panes has been designed and fabricated for the experiment in the explosive gallery. Stresses developed on the glass panes and the SPL in different stages were monitored to study the threshold level of damage. The first crack has been observed in the glass panes at the SPL of 162.3 dB ({minus}3.97 Kpa) and in the 5--20 Hz frequency band.

  2. 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).

  3. The development of a cryogenic over-pressure pump

    SciTech Connect

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

    2014-01-29

    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)

  4. Nonintrusive FBG tube pressure transducers with high overpressure ability

    NASA Astrophysics Data System (ADS)

    Saxena, Indu F.; Hui, Kaleonui J.

    2010-04-01

    Fiber optic sensors offer several advantages over their electrical counterparts, especially for applications in hostile, spark-sensitive environments, because no electrical power is required at the sensors. In addition, the installation of fiber sensors external to fluid carrying conduits facilitates access for troubleshooting and replacement, unlike in-line diaphragm-based sensors. Furthermore, glass fiber pressure sensors have a much higher operating temperature range, which makes them more practical for flammability-prone environments. Multiple fiber Bragg grating (FBG) sensors can be multiplexed along a single fiber optic cable, as opposed to traditional resistive strain gauges, which require individual shielded metal cabling. Applications for such fiber-optic pressure detection systems include the pressure monitoring of flow in fuel lines and their pressure valves. This paper characterizes the application of FBG sensors, with remote access capability, for the nonintrusive pressure monitoring of different types of metallic pipes. We show that pressure changes smaller than one psi can be detected with a tunable diode laser-based detection system. Standard metal pipes of steel, inconel, copper-nickel alloy and titanium are characterized, and the resilience of FBG sensors to an overpressure of up to 1500 psi is demonstrated.

  5. 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.

  6. 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.

  7. 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.

  8. 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. PMID:11397534

  9. Modeling overpressures in sedimentary basins: Consequences for permeability and rheology of shales, and petroleum expulsion efficiency

    SciTech Connect

    Burrus, J.; Schneider, F.; Wolf, S. )

    1994-07-01

    The prediction of overpressures using Institut Francais du Petrole's 2-D numerical model TEMISPACK is applied to several provinces of the world. In the Paris basin, France, normally pressured Liassic shales are shown to have permeabilities around a microdarcy, independently confirmed by laboratory measurements. In contrast, in the Norway section of the North Sea, Williston Basin, Canada, Gulf Coast, and in the Mahakam delta, observed overpressures of 10-50 MPa are consistently modeled with shale permeabilities around 1-10 nanodarcys. This theoretical value fits well with the lowest permeability measured in compacted shales. For these basins, compaction disequilibrium was found to explain most (>85%) of the overpressures. The only exception was the Williston basin in which overpressures observed in the organic-rich Bakken shales are entirely due to hydrocarbon generation. In Mahakam delta, the rheology of shales is nonlinear, i.e., the strength of shales increases rapidly with death. Consequently, shale compaction cannot be described by the linear behavior often assumed in hydrology. In the absence of fault barriers, numerical simulations and geological evidence suggest that overpressured source rocks have low or very low expulsion efficiency, irrespective of their organic content. However, shales with a permeability on the order of a microdarcy do not hinder petroleum migration.

  10. 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.

  11. 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.

  12. Stress switching in subduction forearcs: Implications for overpressure containment and strength cycling on megathrusts

    NASA Astrophysics Data System (ADS)

    Sibson, Richard H.

    2013-07-01

    Seismogenic megathrusts contained within subduction interface shear zones (SISZ) appear generally to be overpressured to near-lithostatic values (λv > 0.9) below forearc hanging-walls. Solution transfer within fine-grained material along the deeper interface (150 < T < 350 °C) contributes to hydrothermal sealing of fractures lowering bulk permeability. Down-dip variations in overpressuring likely affect the depth of the peak in frictional shear resistance which may serve as the prime asperity affecting megathrust rupture. To account for postseismic changes in the velocity structure of the fore-arc hanging-wall following the 1995 Antofagasta, Chile, Mw8.0 megathrust rupture, Husen and Kissling (2001) proposed massive trans-megathrust discharge of fluids across the interface. Such discharges are a form of 'fault-valve' action where the megathrust itself acts as a seal to overpressured fluids derived from within the SISZ and from dehydration of the descending slab. Brittle failure or fault reactivation limits fluid overpressure which is highest at low differential stress under a compressional stress regime. Over much of the forearc hanging-wall of the 2011 Mw9.0 Tohoku-Oki megathrust rupture, focal mechanisms show that the stress-state switched from compressional reverse-slip faulting prefailure to extensional normal-slip faulting postfailure. Mean stress and fault-normal stress thus changed from being greater than vertical stress prefailure, to less than vertical stress postfailure. Reductions in overpressure are expected from a combination of poroelastic effects and fluid loss through fault-fracture networks enhancing postfailure permeability in the changing stress field. Local drainage across the subduction interface increases frictional strength significantly, giving rise to a postfailure distribution of strength asperities. The amplitude of strength variations from such fluid discharge is potentially large (< hundreds of MPa). Time to the next failure is then

  13. Charts for determining potential minimum sonic-boom overpressures for supersonic cruise aircraft

    NASA Technical Reports Server (NTRS)

    Darden, C. M.

    1981-01-01

    Charts which give an estimation of minimum achievable sonic-boom levels for supersonic cruise aircraft are presented. A minimization method based on modified linear theory was analyzed. Results show several combinations of Mach number, altitude, and aircraft length and weight. Overpressure and impulse values are given for two types of sonic boom signatures for each of these conditions: (1) a flat top or minimum overpressure signature which has a pressure plateau behind the initial shock, and (2) a minimum shock signature which allows a pressure rise after the initial shock. Results are given for the effects of nose shape.

  14. Rock magnetic and geochemical process modelling of overpressured sediments from the northwestern Gulf of Mexico (IODP Exp. 308)

    NASA Astrophysics Data System (ADS)

    Franke, C.; Fu, Y.; Riedinger, N.; Gilhooly, W. P.; Jiang, S.; Heslop, D.; von Dobeneck, T.

    2007-12-01

    Four late Quaternary sediment series were recovered from the Brazos-Trinity Minibasin IV and the Ursa Region in the northwestern Gulf of Mexico, offshore Texas and Louisiana (USA) to study in detail the sedimentation processes, slope stability, overpressure and fluid flow mechanisms of rapid sedimentation areas on this passive continental slope. Within the framework of this project, it is specifically important to understand the time frame of the studied processes. Due to a very high sedimentation rate under unconformable conditions (several m/kyr) the classical paleomagnetic approaches are not suitable for time constraints here. Magneto-mineralogic studies as well as electron microscopic analyses yield results on the highly complex magnetic assemblage, which includes various Fe-Ti mineral phases such as (titano-) magnetite, hemoilmenite, and hematite next to Fe-sulphides (mainly greigite and pyrite). The rock magnetic records also show a distinct pattern of either iron oxide or iron sulphide dominated sediment sections, thus it is possible to distinguish between the detrital/continental and postdepositional magnetic signal of the sediments. A conceptual model has been developed combining magnetic and geochemical methods. This enables us to identify various successive non-steady state sedimentation events and to understand the prevailing past ad present environmental conditions. Subsequently we develop a novel approach to further interpret this conceptual model and to constrain a detailed stratigraphic and environmental model for these low-permeability sediments by using multi-parameter correlations as well as non-steady state quantitative geochemical modelling. High resolution rock magnetic records are calibrated with geochemical data sets of acid volatile sulphur (AVS) and chromium reducible sulphur (CRS) estimations. Like that we aim to calculate ages for the distinct sediment packages. The model for the tectonically less complicated Brazos-Trinity drill sites

  15. 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.

  16. 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.

  17. 14 CFR 417.229 - Far-field overpressure blast effects analysis.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... analysis. 417.229 Section 417.229 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.229 Far-field overpressure blast effects analysis. (a) General. A flight safety analysis must establish flight...

  18. 14 CFR 417.229 - Far-field overpressure blast effects analysis.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... analysis. 417.229 Section 417.229 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.229 Far-field overpressure blast effects analysis. (a) General. A flight safety analysis must establish flight...

  19. 14 CFR 417.229 - Far-field overpressure blast effects analysis.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... analysis. 417.229 Section 417.229 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.229 Far-field overpressure blast effects analysis. (a) General. A flight safety analysis must establish flight...

  20. 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. PMID:11837961

  1. 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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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)...

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

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... analysis. 417.229 Section 417.229 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.229 Far-field overpressure blast effects analysis. (a) General. A flight safety analysis must establish flight...

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

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... analysis. 417.229 Section 417.229 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.229 Far-field overpressure blast effects analysis. (a) General. A flight safety analysis must establish flight...

  5. 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.

  6. 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...

  7. 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...

  8. 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...

  9. HAZARDOUS WASTE DESTRUCTION

    EPA Science Inventory

    The paper profiles the current status of hazardous waste thermal destruction in the United States, including facilities and wastes typically handled. The results of extensive EPA-sponsored performance tests are presented for incinerators, industrial boilers, and industrial proces...

  10. Waste destruction by plasma

    NASA Astrophysics Data System (ADS)

    Cretenot, Didier; Vanrenterghem, Jacques; Labrot, Maxime; Pineau, Didier

    The use of arc plasma for waste destruction is addressed. Types of treatable waste, processes for liquid and solid or pasty wastes, and the present state of these techniques in France are described. The efficiency of arc plasma technology in the destruction of liquid organochlorinated waste compounds in commercial size units, particularly mobile units, is demonstrated. Many trials with solid waste demonstrate that plasmas are a highly efficient solution.

  11. 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.

  12. 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.

  13. Sandbox experiments on gravitational spreading and gliding in the presence of fluid overpressures

    NASA Astrophysics Data System (ADS)

    Mourgues, R.; Cobbold, P. R.

    2006-05-01

    Whereas in previous analogue experiments on gravitational spreading and gliding, detachment occurred on a ductile layer, we have used a relatively new technique of injecting compressed air into sand packs so as to simulate the effects of fluid overpressures in sedimentary strata and to trigger slope instabilities. In our experiments, the governing equations yield scales for dimensions, stresses and fluid pressure. However, the more transitory phenomena of production and decrease of overpressure cannot be suitably scaled. By using layers of differing permeability, we are able to produce sharp detachments in models made of sand alone. The experiments involve gravity spreading or gravity gliding. In gravity spreading, propagation of the detachment and of extensional deformation depends on the fluid pressure. For medium values of fluid overpressure, normal faults are closely spaced, numerous and bound rotated blocks. They propagate progressively toward the back of the model. For the highest pressures, the deformation propagates very fast and faults bound non-rotated blocks, which slide on an efficient basal detachment. Fault dips are also controlled by fluid pressure and by frictional resistance at the base. To model gravitational gliding required an apparatus with a more complex system of air injection. We did a series of experiments using injection windows of various lengths and compared the results with predictions from a quasi-3D analytical model of sliding. In contrast with predictions for an infinite slope, sliding depends on (1) the fluid overpressure on the detachment, (2) the fluid overpressure in the body of the sliding sheet, and (3) the shape of the detachment surface. In particular, we show that frictional resistance at the lower edge is a primary control on the dynamics of gliding.

  14. 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

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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. PMID:21994064

  4. Love, psychoanalysis and destruction.

    PubMed

    Ovcharenko, V

    1999-07-01

    The author presents the available information concerning the eminent Russian psychoanalyst Sabina Spielrein, who originally developed the idea of destruction. A major part of the article, which concerns today's popular following of C. G. Jung and S. Freud, is based on documents in the Russian (Moscow) archives, and touches upon the least known periods and facts of her tragic life and of her creative activity. PMID:10424191

  5. 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. PMID:20189299

  6. 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.

  7. [A DESTRUCTIVE SHOULDER ARTHROPATHY].

    PubMed

    Ouhadi, L; Gaudreault, M; Mottard, S; Gillet, Ph

    2016-02-01

    Charcot arthropathy is a progressive, chronic and degenerative destruction of one or several joints caused by a central or peripheral neurological disorder. Approximately 25 % of the patients with syringomyelia develop this arthropathy located in the upper limb in 80 % of the cases. An early etiological diagnosis is essential to begin the treatment of the underlying neurological disorder. Afterwards, a conservative treatment of the arthropathy is preferred. We report the story of a patient with an arthropathy of the left shoulder due to Arnold-Chiari's malformation of type I with syringomyelia. PMID:27141649

  8. 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.

  9. Fluid overpressures on the San Andreas Fault following the passage of the Mendocino Triple Junction

    NASA Astrophysics Data System (ADS)

    Fulton, P. M.; Saffer, D. M.; Bekins, B. A.

    2004-12-01

    Fluid pressures significantly greater than hydrostatic have been hypothesized to account for the weak nature of many large plate-boundary faults. However, on the San Andreas Fault, the hypothesized subsurface processes which could create, sustain, and potentially localize such pressures over millions of years are not well understood. In this study, we use two-dimensional finite element models of coupled fluid flow and heat transport perpendicular to the fault to evaluate hypothesized mechanisms for generating elevated pore pressure. The models account for transient changes in crustal geotherm and thickness of the seismogenic crust in response to the passage of the Mendocino Triple Junction. Theoretical curves of whole-rock fluid content as functions of pressure and temperature allow us to calculate fluid sources due to metamorphic dehydration within the Franciscan mélange as a function of depth and thermal history. Average fluid sources in the seismogenic crust range from 10-18 to 10-16 s-1 over the 15 Myr spanned by our models. We consider a variety of permeability distributions within the models, including a range of homogenous permeability and depth-dependent permeability. We also consider heterogeneous permeability distributions reflecting fault properties and geologic features such as serpentine sills. Our results show that over 15 Myr, thermal expansion of pore fluids due to initial burial, followed by additional heating during exhumation, can create significant overpressures. In addition, models which include fluid sources from metamorphic dehydration of the Franciscan mélange result in pore pressures approaching a significant fraction of lithostatic. Generally, all model results show overpressures extending several kilometers to each side of the fault. Due to the continual nature of many of these processes, overpressures are sustained for millions of years without the need for complex and/or extremely low-permeability seals. Models which include geologic

  10. Microstructural characterization of silicon nitride ceramics processed by pressureless sintering, overpressure sintering, and sinter/HIP

    SciTech Connect

    Selkregg, K.R. ); More, K.L.; Seshadri, S.G.; McMurtry, C.H. )

    1990-01-01

    Silicon nitride ceramics of the same nominal sialon composition have been sintered under different conditions including atmospheric sintering, overpressure sintering, reaction bonded (nitrided pressureless sinter) and sinter/HIP cycles. The sintered ceramics, which exhibited dramatic differences in fracture toughness, have been characterized by x-ray diffraction, scanning electron microscopy, analytical transmission electron microscopy, and image analysis techniques. Fracture toughness data have been correlated to the microstructural and chemical analysis of the grain boundary phases. The microstructure was the strongest influencing factor on the observed fracture toughness difference. 5 refs., 5 tabs.

  11. 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

    2016-07-01

    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. PMID:26985871

  12. Effect of Ar Overpressure Ratio on the Growth of Graphene on Cu(111)

    NASA Astrophysics Data System (ADS)

    Geisler, Heike; Murray, Seamus; Ong, Eng Wen; Mowll, Tyler; Tyagi, Parul; Ventrice, Carl A., Jr.

    2015-03-01

    A graphene growth study was performed on Cu(111) in a UHV chamber by CVD using ethylene. The sample holder consisted of an oxygen series button heater with Ta heat shields to allow annealing the crystal to 900 °C at pressures as high as 100 mTorr. The crystal structure of the surface was determined using LEED. Growth attempts on the clean Cu(111) surface at ethylene pressures as high as 5 mTorr only resulted in trace amounts of graphene being grown on the surface. This is attributed to the low catalytic activity of the Cu(111) surface and the high vapor pressure of Cu at the growth temperature. To suppress the sublimation of Cu, an Ar overpressure was used. Ethylene partial pressures of 2, 5, 10, and 50 mTorr were used, keeping the total pressure at 50 mTorr. The films for 2 and 5 mTorr showed predominately single domain epitaxy. At 10 mTorr ethylene partial pressure, additional diffraction spots 30° out of phase with the Cu(111) substrate were observed. At 50 mTorr of ethylene and no Ar overpressure, broad diffraction arcs were observed in LEED that were +/-15° out of phase with the substrate. Therefore, the carbon deposition rate, which depends on the ethylene partial pressure, has a large effect on the quality of the graphene film. This research was supported by the NSF (DMR-1006411).

  13. Identifying potential gas accumulation sites from Oligocene overpressure data in the Qiongdongnan basin, offshore South China

    SciTech Connect

    Liu Funing )

    1993-05-01

    Overpressure in Oligocene formations in southern Qiongdongnan basin, offshore China, can be determined either by actual measurements in wells or by calculations using data derived from well logs and seismic surveys. The overpressure is mainly the result of undercompaction of Oligocene rocks during rapid loading by Pliocene and Quaternary sedimentation and of the subsequent thermal expansion of fluids in the Oligocene strata. Every formation possesses its own normal compaction trend (plot of shale-interval acoustic transit times vs. depth). The actual fluid pressures and potential pressures can be computed by the equilibrium-depth method. This method must be corrected for the thermal expansion of fluid. The pressure corrections are based on shale-interval transit times from well logs, interval velocities interpreted from vertical seismic profile (VSP) surveys, and stacking velocity from sonic log data of nearby wells. Gas generated from source rocks is assumed to have moved vertically from strata of higher hydraulic pressure potential to those of lower potentials and to have moved laterally and accumulated within areas where the contour closures of a gas equipotential hydraulic-pressure surface (U curves) have lower values. In the study area, the vicinity of the Yacheng gas field, the potential maps (U, gas, and V, water, maps) and hydraulic head profiles can be plotted from values derived either from actual pressure measurements or from calculations. These maps and profiles show prospective areas of gas accumulation. 5 refs., 10 figs., 1 tab.

  14. 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.

  15. 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.

  16. Non-destructive testing and fracture mechanics: A short discussion

    NASA Astrophysics Data System (ADS)

    Zerbst, Uwe; Heckel, Thomas; Carboni, Michele

    2016-02-01

    A short discussion is provided on the relationship between non-destructive testing and fracture mechanics. The basic tasks behind this are to guarantee the safety of a component at a potential hazard loading event, to specify inspection intervals or, alternatively, of demands on non-destructive testing for a fixed inspection regime, to plan accompanying actions for cases of temporary continued operation of structures in which cracks have been detected, and, finally, fatigue strength considerations which take into account initial defects.

  17. Applicability of preparative overpressured layer chromatography and direct bioautography in search of antibacterial chamomile compounds.

    PubMed

    Móricz, Agnes M; Ott, Péter G; Alberti, Agnes; Böszörményi, Andrea; Lemberkovics, Eva; Szoke, Eva; Kéry, Agnes; Mincsovics, Emil

    2013-01-01

    In situ sample preparation and preparative overpressured layer chromatography (OPLC) fractionation on a 0.5 mm thick adsorbent layer of chamomile flower methanol extract prepurified by conventional gravitation accelerated column chromatography were applied in searching for bioactive components. Sample cleanup in situ on the adsorbent layer subsequent to sample application was performed using mobile phase flow in the opposite direction (the input and output of the eluent was exchanged). The antibacterial effect of the fractions obtained from the stepwise gradient OPLC separation with the flow in the normal direction was evaluated by direct bioautography against two Gram-negative bacteria: the luminescence gene tagged plant pathogenic Pseudomonas syringae pv. maculicola, and the naturally luminescent marine bacterium Vibrio fischeri. The fractions having strong activity were analyzed by SPME-GC/MS and HPLC/MS/MS. Mainly essential oil components, coumarins, flavonoids, phenolic acids, and fatty acids were tentatively identified in the fractions. PMID:24645496

  18. Overpressure isoflurane at caesarean section: a study of arterial isoflurane concentrations.

    PubMed

    McCrirrick, A; Evans, G H; Thomas, T A

    1994-01-01

    In this study we have measured arterial concentrations of isoflurane obtained during Caesarean section in two groups of patients. Patients in group 1 received 1% isoflurane throughout operation, whilst those in group 2 received 2% isoflurane for the first 5 min, 1.5% for the next 5 min and 0.8% thereafter. We found that arterial isoflurane concentrations were significantly greater in group 2 than in group 1 (ANOVA, P < 0.05). Isoflurane concentrations greater than 30 micrograms ml-1 were achieved rapidly in most patients in both groups, but there was a large scatter of results. The isoflurane concentration at which awareness or recall may occur is not known, but an "overpressure" technique as described for patients in group 2 may result in fewer patients being at risk of awareness. PMID:8110537

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

    DOE PAGESBeta

    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 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

  20. Rupturing in overpressured crust during compressional inversion—the case from NE Honshu, Japan

    NASA Astrophysics Data System (ADS)

    Sibson, Richard H.

    2009-08-01

    Inboard from the subduction interface in NE Honshu, the crustal seismogenic zone which overlies the dehydrating subducting slab is generally from 10 to 20 km deep. Arc-normal shortening is manifested by patterns of geodetic strain accumulation and by a predominance of moderate-to-steep reverse faulting, reflecting compressional inversion which has been ongoing since the Late Pliocene. Several strong recent earthquakes have involved reverse-slip rupturing on inherited normal faults along the margins of Miocene extensional basins flanking the magmatic arc both to the east and to the west. From focal mechanism analyses and aftershock distributions, the mainshocks involved close-to-pure reverse slip on faults dipping at 40-60° along the basin margins. These earthquakes represent increments of the continuing compressional inversion which is not far advanced, however, because in several instances the fault hangingwalls are occupied by Neogene sedimentary basins which are still, locally, up to 6 km deep. On the assumption of horizontal maximum compressive stress, rupturing during these earthquakes took place on faults poorly oriented for frictional reactivation, often approaching the lock-up angle expected for standard rock friction. Continued reactivation of such structures, in preference to the formation of more favourably oriented low-dipping thrusts, requires near-lithostatic ( Pf → σ 3) but probably heterogeneous fluid-overpressuring within the lower half of the seismogenic zone. A range of geophysical evidence—local occurrence of bright-spot reflectors, low-velocity zones, anomalous Vp/Vs ratios, and high electrical conductivity—support the existence of a fluid-rich (H 2O ± CO 2), variably overpressured mid-crust which extends into the lower half of the upper crustal seismogenic zone, especially in the vicinity of the major fault systems. Subhorizontal magmatic sills and arrays of hydrothermally filled extension fractures formed by hydraulic fracturing when

  1. Simultaneous determination of water-soluble vitamins by over-pressure layer chromatography and photodensitometric detection.

    PubMed

    Postaire, E; Cisse, M; Le Hoang, M D; Pradeau, D

    1991-04-01

    An over-pressure layer chromatographic procedure with photodensitometric detection for the simultaneous determination of water-soluble vitamins in multivitamin pharmaceutical preparations was developed and evaluated. The method uses high-performance TLC (HPTLC) plates with silica gel as the thin-layer, and an n-butanol:pyridine:water mixture (50:35:15, v/v/v) as mobile phase at a rate of 0.25 mL/min for baseline separation. The quantitation was carried out without derivatization (vitamin B1, vitamin B2, vitamin B6, folic acid, nicotinamide, vitamin C) or after spraying ninhydrin reagent (calcium pantothenate) or 4-dimethylaminocinnamaldehyde (vitamin B12, biotin). This was applied to the analysis of multivitamin solutions. Satisfactory relative standard deviations and good recovery were obtained for all the vitamins examined. It was concluded that this method is fast, accurate, specific, and suitable for routine quality control use. PMID:1865338

  2. An analytical solution describing the shape of a yield stress material subjected to an overpressure

    NASA Astrophysics Data System (ADS)

    Hovad, E.; Spangenberg, J.; Larsen, P.; Thorborg, J.; Hattel, J. H.

    2016-06-01

    Many fluids and granular materials are able to withstand a limited shear stress without flowing. These materials are known as yields stress materials. Previously, an analytical solution was presented to quantify the yield stress for such materials. The yields stress is obtained based on the density as well as the spread length and height of the material when deformed in a box due to gravity. In the present work, the analytical solution is extended with the addition of an overpressure that acts over the entire body of the material. This extension enables finding the shape of a yield stress material with known density and yield stress when for instance deformed under water or subjected to a forced air pressure.

  3. 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). PMID:23315947

  4. 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.

  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. PMID:22698585

  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. 27 CFR 19.691 - Voluntary destruction.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., State, and local environmental laws and regulations. (e) Record of destruction. The proprietor shall... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Voluntary destruction. 19... Voluntary Destruction Voluntary Destruction § 19.691 Voluntary destruction. (a) General. Spirits,...

  8. 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.

  9. 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.

  10. 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

  11. Overpressure retardation of organic-matter maturation and petroleum generation: A case study from the Yinggehai and Qiongdongnan Basins, South China Sea

    SciTech Connect

    Hao Fang; Sun Yongchuan; Li Sitian; Zhang Qiming

    1995-04-01

    Three superimposed pressure systems developed in the Yinggehai Basin, South China Sea, as indicated by seismic data, well logs, and direct pressure measurements. The organic maturation profile is nonlinear, with three nonparallel segments that correspond to the shallow, normal-pressured system; the intermediate, overpressured system; and the deep, strongly overpressured system respectively. The intermediate and deep overpressured systems have abnormally low R{sub 0} gradients. The organic maturity of these overpressured rocks is significantly lower than the maturity of normal-pressured source rocks in nearby wells with similar thermal histories and does not math the thermal histories of the rocks. Such an organic maturity anomaly is distinctly different from those caused by variation in activation energies, conductivity contrasts, and hydrologic effects, and is confirmed to be the result of overpressure retardation. The degree to which the organi-matter maturation is retarded, expressed as the difference between predicted and measured vitrinite reflectance, increases exponentially with increasing fluid pressure, confirming that pressure increases the activation energies of organi-matter maturation reactions. Overpressure retardation has been proven to be conditional and quite important for clearly understanding petroleum generation, migration, and accumulation in overpressured sedimentary basins.

  12. 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

  13. 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

  14. 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

  15. Seismic chimneys in the Southern Viking Graben - Implications for palaeo fluid migration and overpressure evolution

    NASA Astrophysics Data System (ADS)

    Karstens, Jens; Berndt, Christian

    2015-02-01

    Detailed understanding of natural fluid migration systems is essential to minimize risks during hydrocarbon exploration and to evaluate the long-term efficiency of the subsurface storage of waste water and gas from hydrocarbon production as well as CO2. The Southern Viking Graben (SVG) hosts numerous focused fluid flow structures in the shallow (<1000 m) subsurface. The seismic expressions of vertical fluid conduits are variously known as seismic chimneys or pipes. Seismic pipes are known to form large clusters. Seismic chimneys have so far been described as solitary structures. Here, we show that the study area in the SVG hosts more than 46 large-scale vertical chimney structures, which can be divided in three categories implying different formation processes. Our analysis reveals that seal-weakening, formation-wide overpressure and the presence of free gas are required to initiate the formation of vertical fluid conduits in the SVG. The presence of numerous vertical fluid conduits implies inter-stratigraphic hydraulic connectivity, which significantly affects the migration of fluids in the subsurface. Chimney structures are important for understanding the transfer of pore pressure anomalies to the shallow parts of the basin.

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

    NASA Astrophysics Data System (ADS)

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

    2012-05-01

    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.

  17. 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.

  18. 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.

  19. 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. PMID:26433903

  20. 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)

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

    DOE PAGESBeta

    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 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

  2. 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.

  3. 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.

  4. 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

  5. Structural response of reactor-core hexcan subassemblies subjected to dynamic overpressurization under accident conditions

    SciTech Connect

    Pfeiffer, P.A.; Kulak, R.F.

    1993-01-01

    This paper presents a two-dimensional structural analysis for the evaluation of a single core subassembly due to internal overpressure associated with possible failure of fuel pins having high fission gas plenum pressure. Structural models are developed for the subassemblies and their surroundings with emphasis on the critical physical aspects of the problem. With these models the strains, deformations and the extent of permanent damage (plastic strain) to the subassemblies can be assessed. The nonlinear structural analyses was performed with a finite element program called STRAW (Structural Transient Response of Assembly Wrappers). This finite element program is applicable to nonlinear large displacement problems. The results of this study indicate that the permanent deformation (damage) is strongly influenced by the rise time (time to reach peak pressure) of the pressure pulse and the pressure in the fuel pin. The rise time is influenced by the opening time of the flow path for release of gas from the fuel pin plenum. Several examples are illustrated with various rise times and pressure magnitudes and the resulting permanent deformation of the hexcan wall.

  6. Structural response of reactor-core hexcan subassemblies subjected to dynamic overpressurization under accident conditions

    SciTech Connect

    Pfeiffer, P.A.; Kulak, R.F.

    1993-06-01

    This paper presents a two-dimensional structural analysis for the evaluation of a single core subassembly due to internal overpressure associated with possible failure of fuel pins having high fission gas plenum pressure. Structural models are developed for the subassemblies and their surroundings with emphasis on the critical physical aspects of the problem. With these models the strains, deformations and the extent of permanent damage (plastic strain) to the subassemblies can be assessed. The nonlinear structural analyses was performed with a finite element program called STRAW (Structural Transient Response of Assembly Wrappers). This finite element program is applicable to nonlinear large displacement problems. The results of this study indicate that the permanent deformation (damage) is strongly influenced by the rise time (time to reach peak pressure) of the pressure pulse and the pressure in the fuel pin. The rise time is influenced by the opening time of the flow path for release of gas from the fuel pin plenum. Several examples are illustrated with various rise times and pressure magnitudes and the resulting permanent deformation of the hexcan wall.

  7. The effects of As overpressure and diffusion source on the diffusion of Mn in GaAs

    NASA Astrophysics Data System (ADS)

    Wu, C. H.; Hsieh, K. C.

    1992-12-01

    Data are presented to show the effect of As overpressure on the diffusion of Mn in GaAs using four different Mn sources. These sources include solid Mn thin film deposited directly on the GaAs substrate and Mn vapors from pure Mn, MnAs, and Mn3As solids. In the circumstance for which a solid Mn film is used as the diffusion source, a nonuniform doping distribution and poor surface morphology is obtained due to a reaction between the Mn film and the GaAs matrix. The degraded surface consists of a layer of polycrystalline cubic alloy having a lattice constant of nearly 8.4 Å and a composition close to MnGa2 with a small amount of As. Of the remaining diffusion sources (Mn, MnAs, and Mn3As), only MnAs consistently produces a uniform doping distribution and smooth surface morphology. For diffusions at 800 °C, a uniform surface hole carrier concentration as high as 1020/cm3 can be obtained using MnAs as the source. The As overpressure is found to drastically alter the Mn diffusion profile, and Mn, like Zn, may diffuse in GaAs interstitial-substitutionally. Vapor from both the Mn and Mn3As solids degrade the GaAs surface. Mn3As, however, uncharacteristically degrades the surface more rapidly although the details of such are not well understood. With the presence of a high As overpressure, however, both surfaces of the Mn and Mn3As sources are converted to (Mn,As) compounds, the compositions being close to MnAs. High enough As overpressures are shown to completely suppress the GaAs surface degradation which is evident when Mn3As alone is used as the diffusion source.

  8. 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.

  9. Slow wavespeeds and fluid overpressure in a region of shallow geodetic locking and slow slip, Hikurangi subduction margin, New Zealand

    NASA Astrophysics Data System (ADS)

    Bassett, Dan; Sutherland, Rupert; Henrys, Stuart

    2014-03-01

    Travel times recorded onshore from active-source marine seismic surveys were used to determine Hikurangi forearc wavespeeds. Ray-path midpoints sample forearc crust above the shallow (<10-12 km) subduction thrust. The southern region is locked to c. 30 km depth, exhibits slow slip at 30-45 km depth, and is similar to other subduction zones. Our 1D southern model has a rapid increase in seismic velocity (Vp) from the seabed to 4 km depth, consistent with rapidly-deposited clastic sediments, and near-constant Vp=5.0±0.2 km/s at depths of 4-10 km within the forearc. The northern region has slow-slip events at shallow depths of c. 5-15 km, beneath the volume sampled by our analysis. Average travel times at offsets of 20-80 km are >1 s more than at equivalent offsets in the south, and Vp increases with depth within the forearc from 3.5±0.1 km/s at 4 km depth to 4.5±0.2 km/s at 10 km depth. We interpret the low wavespeeds in terms of compaction disequilibrium and compare seismic inferences of anomalously-high porosity (>10%) with hydrostatic reference compaction models to show effective stress is low in both the north (27±10 Mpa) and south (36±14 MPa). In the south, pore space and conduits have a high chance of being localized on faults or sand layers, the wedge is clearly compressionally critical, and we suggest the higher seismic velocities recorded primarily reflect higher effective stress levels transmitted through the rock framework. The observed wedge geometry and our estimate of fluid pressure within the wedge (λ=0.87±0.05) suggest a weak overpressured subduction thrust. In the north, we suggest high fluid pressure is maintained by a large fluid inventory from subducting sediment, a pore-space geometry characterized by pervasively-fractured rock and mudstone, and a lower mean stress due to its stable and non-critical wedge geometry. We consider both end-member assumptions of convergent and tensile failure, the latter of which reveals the possibility of near

  10. 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

  11. 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. PMID:26104291

  12. 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…

  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. NON-DESTRUCTIVE BEAM MEASUREMENTS.

    SciTech Connect

    BAI,M.

    2004-07-05

    In high energy accelerators, especially storage rings, non-destructive beam measurements are highly desirable to minimize the impact on the beam quality. In principle, the non-destructive tools can be either passive detectors like Schottky, or active devices which excite either longitudinal or transverse beam motions for the corresponding measurements. An example of such a device is an ac dipole, a magnet with oscillating field, which can be used to achieve large coherent betatron oscillations. It has been demonstrated in the Brookhaven AGS that by adiabatically exciting the beam, the beam emittance growth due to the filamentation in the phase space can be avoided. This paper overviews both techniques in general. In particular, this paper also presents the beam tune measurement with a Schottky detector, phase advance measurements as well as nonlinear resonance measurements with the ac dipoles in the Brookhaven RHIC.

  15. 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.

  16. 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.

  17. Quantitative assessment of magmatic refill and overpressure in crustal reservoirs by monitoring He isotope composition from volcanic gases: the case of Mt Etna (Italy)

    NASA Astrophysics Data System (ADS)

    Paonita, Antonio; Caracausi, Antonio; Martelli, Mauro; Rizzo, Andrea

    2016-04-01

    occurred at all the sampled emissions some months before the onset of eruptions, due to deep magma recharges. This behaviour has been systematic for all the main eruptive phases occurred at Mt Etna since 2001. For most of the events, we quantitatively estimated the rate of magmatic refill during the pre-eruptive recharges of the system, as well as the growth of the overpressure in the deep chamber. Failure of the wall rocks and dike opening is also explained in the case of 2001 eruption, because chamber overpressure overcame the yield strength of rocks. The results suggest that key parameters as the rate of magma inflow and the volume change in deep chamber can be estimated prior to impending eruptions and directly compared to inferences from geodetic signals.

  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...

  19. 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...

  20. 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...

  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...

  2. 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

  3. 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

  4. 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

  5. Evaluation and detection of overpressures in a Deltaic Basin: The Sisi Field case history, offshore Mahakam, Kutei Basin, Indonesia

    SciTech Connect

    Grosjean, Y. ); Bois, M.; De Pazzis, L. ); Burrus, J. )

    1994-07-01

    Widespread overpressure occurrences in the Mahakama delta area have caused a number of kicks and several blow-outs during earlier exploration. A review of pore pressure indications was conducted in conjunction with an extensive reinterpretation of seismic and well data basin wide. The iso-pressure lines were found to be broadly parallel to the facies change from sandy, delta-front deposits to outer shelf and slope shales, and are not associated with organic matter maturation or clay diagenesis. Overpressures are reached at depths ranging from 1000 m to more than 4000 m, depending on the facies. A 2-D numerical basin model calibrated on observed pressure profiles at wells indicated that the excess pressures were a direct function of the variable drainage efficiency of the formations by interbedded sands. The Sisi discovery located at the eastern, distal extremity of the upper Miocene deltaic sands provided a unique opportunity for a more detailed analysis. A hypothesis of widespread decoupling between reservoir and shale pore pressures was tested against well data during appraisal drilling. D-exponent plots and gas shows were carefully monitored to assess the excess pressures, and quantitative estimates of the shale pore pressures were computed from sonic logs. A regionally consistent calibration was achieved, which confirmed very large discrepancies compared to the pressures measured in interbedded permeable reservoirs. These conclusions have since been generalized to other areas of the basin, where they allowed safer drilling practices to be established as demonstrated by the observed reduction of lost time.

  6. 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.

  7. 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)

  8. Highly destructive perianal Crohn's disease.

    PubMed Central

    Shetty, A. K.; Udall, J.; Schmidt-Sommerfeld, E.

    1998-01-01

    This article reports a case of highly destructive perianal Crohn's disease in a 15-year-old boy who presented with fecal impaction and incontinence. Both upper and lower gastrointestinal tract endoscopy were unrevealing. Treatment with intravenous prednisolone and broad-spectrum antibiotics supplemented by enteral feeding with an elemental diet resulted in prompt recovery. However, healing of his perianal lesions began only after a diverting colostomy. Awareness of this uncommon entity is important because prompt recognition can lead to early institution of appropriate treatment and avoid further morbidity. PMID:9727293

  9. 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.

  10. [Destructive spondylarthropathy in dialysis patients].

    PubMed

    Stein, G; Schneider, A; Marzoll, I; Sperschneider, H; Ritz, E

    1991-01-01

    Back pain and a cervicobrachial syndrome, as well as progressive sensory and motor deficits as far as symptoms of paraplegia, developed in two dialysis patients two and five years after the start of dialysis. One was a 60-year-old woman with pyelonephritis, the other a 55-year-old man with glomerulonephritis. There were typical radiological signs of destructive spondylarthropathy (narrowed intervertebral spaces and slippage of the vertebral bodies). The female patient required several operations (spondylothesis and orthothesis) and both patients received daily 10,000 IU vitamin D and 3-4 g calcium carbonate. In the woman the destructive process no longer progressed one year after onset of symptoms, but she still required many analgesics. She died three months later of circulatory failure. The man died four weeks after the onset of symptoms from purulent meningitis. At autopsy only renal fibrous ostitis was still demonstrable. Amyloidosis resulting from an increase in beta 2-microglobulin level were excluded by both histological and immunohistochemical examinations. PMID:1985800

  11. 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.

  12. 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. PMID:25774952

  13. 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.

  14. 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. PMID:26164838

  15. 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

  16. 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.

  17. 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).

  18. Acoustic signal associated with the bursting of a soap film which initially closes an overpressurized cavity . Experiment and theory

    NASA Astrophysics Data System (ADS)

    Vidal, V.; Géminard, J.-C.; Divoux, T.; Melo, F.

    2006-12-01

    We report an experimental study of the sound produced by the bursting of a thin liquid film, which initially closes an overpressurized cylindrical cavity. There is a need for a deep understanding of the phenomenon, which can be very useful in numerous practical cases. For instance, in the nature, the volcanologists observe the bursting of large, elongated, gas-bubbles at the surface of lava lakes and record the associated sound emission. One can wonder which pieces of information they can get from such acoustic measurements. For a didactic purpose, we provide also the reader with all the theoretical background necessary for the understanding of the physical processes that govern the various characteristics of the acoustic signals: the cavity geometry governs the frequency; the viscous dissipation and the radiation are responsible for the damping; the acoustic energy informs about the characteristic time associated with the film-rupture more than about the energy initially loaded in the cavity.

  19. Creative Destruction: Singapore's Speak Good English.

    ERIC Educational Resources Information Center

    Rubdy, Rani

    2001-01-01

    Attempts to show that the move to stem the popularity of Singlish (Singapore English) is another manifestation of the notion of creative destruction, currently being proposed as a strategy to improve partial destruction of existing economic ideas and structures that rapidly obsolesce with the emergence of new ones. Argues that attempts to replace…

  20. 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...

  1. 10 CFR 1017.26 - Destruction.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Destruction. 1017.26 Section 1017.26 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) IDENTIFICATION AND PROTECTION OF UNCLASSIFIED CONTROLLED NUCLEAR INFORMATION Physical Protection Requirements § 1017.26 Destruction. A document marked as containing UCNI must...

  2. 10 CFR 1017.26 - Destruction.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Destruction. 1017.26 Section 1017.26 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) IDENTIFICATION AND PROTECTION OF UNCLASSIFIED CONTROLLED NUCLEAR INFORMATION Physical Protection Requirements § 1017.26 Destruction. A document marked as containing UCNI must...

  3. 27 CFR 40.253 - Destruction.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... OF THE TREASURY (CONTINUED) TOBACCO MANUFACTURE OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND... have been entered in the factory record as manufactured or received, without salvaging the tobacco, he... shall make an entry of such destruction in his factory record, and where destruction without...

  4. 27 CFR 40.253 - Destruction.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... OF THE TREASURY (CONTINUED) TOBACCO MANUFACTURE OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND... have been entered in the factory record as manufactured or received, without salvaging the tobacco, he... shall make an entry of such destruction in his factory record, and where destruction without...

  5. 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…

  6. 27 CFR 40.253 - Destruction.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2012-04-01 2011-04-01 true Destruction. 40.253 Section 40.253 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF... § 40.253 Destruction. When a manufacturer of tobacco products desires to destroy tobacco products...

  7. 27 CFR 40.253 - Destruction.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2014-04-01 2014-04-01 false Destruction. 40.253 Section 40.253 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT... § 40.253 Destruction. When a manufacturer of tobacco products desires to destroy tobacco products...

  8. Photocatalyzed destruction of water contaminants

    SciTech Connect

    Ollis, D.F. ); Pelizzetti, E. ); Serpone, N. )

    1991-09-01

    Heterogeneous photocatalysis is a process in which the illumination of an oxide semiconductor, usually the anatase form of titanium dioxide, produces photoexcited electrons (e{sup {minus}}) and holes (h{sup +}). These can migrate to the oxide surface and participate in half-cell reactions that are part of a closed, catalytic cycle. In the aqueous phase, the illuminated surface is widely regarded as a producer of hydroxyl radicals (e.g., h{sup +} + OH{sup {minus}} {yields} {center dot}OH), and these and other highly oxidizing initial products of this indirect photochemistry go on to attack oxidizable contaminants. This article highlights recent developments in photocatalysis that are applicable to water treatment. Topics discussed include the generality of photocatalysis for complete contaminant destruction (mineralization); some specific contaminant classes of interest (chlorinated aromatics, surfactants, herbicides, and pesticides); the use of solar versus artificial illumination; the influence of additional oxidants such as H{sub 2}O{sub 2}; catalyst forms (suspended vs. immobilized); and related potential applications of photocatalysis (metal recovery and total organic carbon (TOC) analyses).

  9. Self-destructiveness in adolescence.

    PubMed

    Noshpitz, J D

    1994-01-01

    This study is an attempt to formulate the dynamics of the group of adolescents involved in major drug use and other antisocial behavior. As consultant to a drug rehabilitation center for teenagers, the author has had occasion to interview and evaluate a large number of youths whose lives had taken such a turn. Certain aspects of the life style and behavior patterns of these young people show striking similarities. In particular, their behavior evidences the presence of a central self-destructive moiety which can be likened to a negative ego ideal; this acts to shape and to direct their lives. This element in the character structure of these patients is described in clinical and theoretical (developmental) terms, with special address to: a chronic low-grade sense of inner malaise, a tendency to self-blame for whatever goes wrong for family and close friends, feelings of alienation from the larger society around them, behavioral provocativeness in the service of seeking the relief that punishment brings, recurrent gestures of self-mutilation, frequent involvement with cults of devil worship, a record of multiple antisocial acts punctuated by numerous arrests, and repeated suicidal gestures and attempts. The origins of the negative regulatory superego elements which make for this type of psychopathology are explored. PMID:7992866

  10. 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.

  11. 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.

  12. 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

  13. Near-Sea Floor Compaction and Shallow Overpressures: Constrains From High Strain Consolidation Tests on ODP Sediments

    NASA Astrophysics Data System (ADS)

    Olgaard, D. L.; Dugan, B. E.; Gooch, M. J.

    2001-12-01

    Before launching into the title topic, I will share a few ``memories of torsion testing'' that exemplify one of the breakthrough contributions Mervyn Paterson has made to Geodynamics. Mervyn and his machines, the torsion apparatus in particular, have revolutionized structural geology by providing the means to quantify crustal and mantle deformation processes up to and beyond the high shear strains observed in the field. High strain is also important in basin evolution. High strain consolidation tests are used to help understand mechanical and fluid flow processes in deforming sediments on continental slopes. Clay-rich sediments compact from 70% to less than 40% porosity within 1000m below the sea floor [mbsf]. Clay-rich sediments have notoriously low permeabilities and, when combined with rapid deposition rates, can cause pore-fluid pressures greatly in excess of hydrostatic at shallow depths. Such high overpressures are particularly hazardous to slope stability and to deepwater drilling. Recently, Dugan and Flemings [Science, 289, 2000] used forward sedimentation models for the New Jersey continental slope calibrated with ODP data, to predict fluid pressures near lithostatic to depths of 640m. In the current study we use consolidation tests to verify these model predictions. Silty-clay cores were collected from depths of 60 to 650mbsf during ODP Leg 1073. Five samples were tested under drained, uniaxial strain conditions, i.e. zero radial displacement. Cylindrical samples were first subjected to a hydrostatic effective stress of ~0.2MPa, then axially loaded at a constant rate of 0.7kPa/min to maintain drained conditions. Pore pressure [brine] was held constant at 3.5MPa. Confining pressure was increased to maintain the uniaxial strain condition. P-wave velocities and permeabilities were measured at various stress conditions on two samples. The samples compacted rapidly at low stresses, then at decreasing rates as stress increased. A total compaction of 22

  14. 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

  15. 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

  16. 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.

  17. 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. PMID:27192290

  18. Coupled modelling of the effect of overpressure on water discharge in a tile drainage system

    NASA Astrophysics Data System (ADS)

    Henine, H.; Nédélec, Y.; Ribstein, P.

    2014-04-01

    The effect of subsurface drainage on agricultural catchment outflow has been debated for quite some time. Concerning downstream peak flow, it is a complex task to predict the impact of agricultural drainage because different flow media are involved: the soil, pipe drainage networks and open channel networks. In France, drain pipes are designed to operate under a free-surface flow condition. Nevertheless, during intense rainfall events, some pipe sections may flow under pressurised conditions, so that a complex interaction between pipe networks and groundwater flows appears in the vicinity of these sections. In this paper, an integrated modelling strategy is considered in order to analyse these flow interactions. A 1D Saint-Venant network model is combined with a 2D Boussinesq shallow groundwater flow model by means of special internal boundary conditions which take into account the flow interactions. This study follows field experiments conducted in a small subsurface drained catchment, where drainage discharge and pressure heads were monitored in a buried pipe collector and water table profiles were monitored in the field. The simulation results of the coupled model are in good agreement with experimental observations. Moreover, it satisfactorily simulates the behaviour of the drainage system during the pressurisation stages. The model is also applied to a scenario addressing the effect of pressurisation, as compared to non-pressurisation, at the outlet. The coupled model reveals the relation existing between pipe pressurisation and hydrograph timing. Pipe pressurisation results in temporary storage of discharging water, which is released later when pressurisation stops.

  19. 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.

  20. 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...

  1. What triggers large submarine landslides on <2° slopes? A study on overpressure generation in slow deposition environments

    NASA Astrophysics Data System (ADS)

    Urlaub, M.; Talling, P. J.; Zervos, A.; Masson, D. G.; Clayton, C. R.

    2012-12-01

    Large submarine landslides that exceed in size landslides on land by up to two orders of magnitude occur on slope angles of less than 2°. Mechanically, failure of soil on nearly flat slopes is only possible when high ratios of excess pore pressure to effective stress prevail which significantly reduce the shearing resistance of the sediment. It has been suggested that the combinations of rapid deposition of low permeability sediment with lateral fluid flow precondition the slope to a tipping point, and that earthquakes act as final trigger to cause failure of low gradient slopes. However, slope failure is also observed at continental margins that experience comparatively low rates of sediment deposition. We develop a fully coupled 2D stress-fluid flow finite element model of an entire continental slope in order to investigate excess pore pressure generation due to consolidation under slow sediment deposition. Different permeability-porosity relationships, permeability anisotropies, compressibility, sediment strengths or inclusion of aquifers are modelled, but resulting excess pore pressures are too low to significantly decrease effective stress anywhere along the slope. This result indicates that we may miss out a dominant pore pressure generating process in areas of slow deposition, or that factors other than overpressure drive slope failure.

  2. 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.

  3. 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

  4. 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. PMID:22719989

  5. 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

    2013-06-01

    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. PMID:23570732

  6. 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

  7. 39 CFR 762.41 - Advice of non-receipt or loss, destruction, or mutilation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... mutilation. 762.41 Section 762.41 Postal Service UNITED STATES POSTAL SERVICE POSTAL SERVICE DEBT OBLIGATIONS..., or mutilation. (a) In the event of the non-receipt, loss, or destruction of a Disbursement Postal Money Order, or the mutilation or defacement of a Disbursement Postal Money Order to an extent...

  8. 39 CFR 762.41 - Advice of non-receipt or loss, destruction, or mutilation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... mutilation. 762.41 Section 762.41 Postal Service UNITED STATES POSTAL SERVICE POSTAL SERVICE DEBT OBLIGATIONS..., or mutilation. (a) In the event of the non-receipt, loss, or destruction of a Disbursement Postal Money Order, or the mutilation or defacement of a Disbursement Postal Money Order to an extent...

  9. 39 CFR 762.41 - Advice of non-receipt or loss, destruction, or mutilation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... mutilation. 762.41 Section 762.41 Postal Service UNITED STATES POSTAL SERVICE POSTAL SERVICE DEBT OBLIGATIONS..., or mutilation. (a) In the event of the non-receipt, loss, or destruction of a Disbursement Postal Money Order, or the mutilation or defacement of a Disbursement Postal Money Order to an extent...

  10. 39 CFR 762.41 - Advice of non-receipt or loss, destruction, or mutilation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... mutilation. 762.41 Section 762.41 Postal Service UNITED STATES POSTAL SERVICE POSTAL SERVICE DEBT OBLIGATIONS..., or mutilation. (a) In the event of the non-receipt, loss, or destruction of a Disbursement Postal Money Order, or the mutilation or defacement of a Disbursement Postal Money Order to an extent...

  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. 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.

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

    PubMed

    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

  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. Boiling liquid expanding vapor explosion: experimental research in the evolution of the two-phase flow and over-pressure.

    PubMed

    Chen, Sining; Sun, Jinhua; Wan, Wei

    2008-08-15

    In a boiling liquid expanding vapor explosion (BLEVE), the superheating and boiling of the liquefied gas inside the vessel as it fails is important information necessary to understand the mechanism of this type of disaster. In this paper, a small-scale experiment was developed to investigate the possible processes that could lead to a BLEVE. Water was used as the test fluid. High-speed video was utilized to observe the two-phase flow swelling which occurred immediately following the partial loss of containment through a simulated crack. The velocity of the two-phase swelling was measured along with pressure and temperature. It was observed that initially a mist-like two-phase layer was rapidly formed on the liquid surface (~3-4 ms) after the vessel opened. The superheated liquid rapidly boiled and this accelerated upwards the two-phase layer, the whole liquid boiled after about 17 ms form opening. It was supposed that the swelling of the two-phase layer was the possible reason for the first over-pressure measured at the top and bottom of the vessel. From 38 ms to 168 ms, the boiling of the superheated liquid weakened. And from 170 ms, the original drop/mist-like two-phase flow turned into a churn-turbulent bubbly two-phase flow, rose quickly in the field of the camera and eventually impacted the vessel top wall. The force of its impact and "cavitation" and "choke" following with the two-phase ejection were maybe main reasons for the second obvious pressure increasing. PMID:18261848

  16. 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

  17. 9 CFR 51.6 - Destruction of animals; time limit for destruction of animals.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... ANIMALS DESTROYED BECAUSE OF BRUCELLOSIS Indemnity for Cattle, Bison, and Swine § 51.6 Destruction of... be deemed necessary to accomplish destruction of bison subject to this part. (c) Swine. The claimant shall be responsible for insuring that swine subject to this part shall be sold under permit to...

  18. 9 CFR 51.6 - Destruction of animals; time limit for destruction of animals.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... ANIMALS DESTROYED BECAUSE OF BRUCELLOSIS Indemnity for Cattle, Bison, and Swine § 51.6 Destruction of... be deemed necessary to accomplish destruction of bison subject to this part. (c) Swine. The claimant shall be responsible for insuring that swine subject to this part shall be sold under permit to...

  19. 9 CFR 51.6 - Destruction of animals; time limit for destruction of animals.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... ANIMALS DESTROYED BECAUSE OF BRUCELLOSIS Indemnity for Cattle, Bison, and Swine § 51.6 Destruction of... be deemed necessary to accomplish destruction of bison subject to this part. (c) Swine. The claimant shall be responsible for insuring that swine subject to this part shall be sold under permit to...

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

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... ANIMALS DESTROYED BECAUSE OF BRUCELLOSIS Indemnity for Cattle, Bison, and Swine § 51.6 Destruction of... be deemed necessary to accomplish destruction of bison subject to this part. (c) Swine. The claimant shall be responsible for insuring that swine subject to this part shall be sold under permit to...

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

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... ANIMALS DESTROYED BECAUSE OF BRUCELLOSIS Indemnity for Cattle, Bison, and Swine § 51.6 Destruction of... be deemed necessary to accomplish destruction of bison subject to this part. (c) Swine. The claimant shall be responsible for insuring that swine subject to this part shall be sold under permit to...

  2. 27 CFR 24.235 - Taxpayment or destruction of spirits.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Spirits § 24.235 Taxpayment or destruction of... of tax procedures of 27 CFR 19.522(c). (b) Destruction of spirits. The proprietor who wants to..., the proposed date and method of destruction, and the reason for destruction. Spirits may not...

  3. 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.

  4. Weapons of mass destruction. Research report

    SciTech Connect

    Ryan, M.W.

    1997-04-01

    The policy of mutual destruction limited the use of weapons of mass destruction (WMD) during the Cold War but has much less significance in today`s global environment not only because of multiple regional instability and motivation to acquire, but also increased availability of resources and technologies to build WMD. Proliferation of weapons of mass destruction is a preeminent security threat in the 1990`s. The US has policies and strategies to stem WMD proliferation and to counter the effects of their use. This paper will identify ways to deter threats of WMD against the United States through counterproliferation strategies of counterforce, active defense, and passive defense. Discussion includes aspects which challenge US interests and place greater burden on policymakers. These include politics, economics, technology and the global mindset.

  5. Altering the timing of academic prompts to treat destructive behavior maintained by escape.

    PubMed Central

    Ebanks, Mercedes E; Fisher, Wayne W

    2003-01-01

    Following a functional analysis showing that destructive behavior was reinforced by escape, we altered the aversiveness of task demands by interspersing easy and difficult tasks and by presenting a corrective prompt as an antecedent event the next time a previously failed item was presented; this procedure was compared with one in which the corrective prompt was provided as an immediate consequence. Results of a reversal design showed that the antecedent prompt acted as an establishing operation and reduced destructive behavior to zero. PMID:14596576

  6. Method for non-destructive testing

    DOEpatents

    Akers, Douglas W.

    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.

  7. 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 Defense Other Regulations Relating to National Defense INFORMATION SECURITY OVERSIGHT OFFICE, NATIONAL ARCHIVES AND RECORDS ADMINISTRATION CLASSIFIED NATIONAL SECURITY INFORMATION Safeguarding §...

  8. 27 CFR 40.253 - Destruction.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2011-04-01 2011-04-01 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, AND PROCESSED TOBACCO Operations by Manufacturers...

  9. The β-catenin destruction complex.

    PubMed

    Stamos, Jennifer L; Weis, William I

    2013-01-01

    The Wnt/β-catenin pathway is highly regulated to insure the correct temporal and spatial activation of its target genes. In the absence of a Wnt stimulus, the transcriptional coactivator β-catenin is degraded by a multiprotein "destruction complex" that includes the tumor suppressors Axin and adenomatous polyposis coli (APC), the Ser/Thr kinases GSK-3 and CK1, protein phosphatase 2A (PP2A), and the E3-ubiquitin ligase β-TrCP. The complex generates a β-TrCP recognition site by phosphorylation of a conserved Ser/Thr-rich sequence near the β-catenin amino terminus, a process that requires scaffolding of the kinases and β-catenin by Axin. Ubiquitinated β-catenin is degraded by the proteasome. The molecular mechanisms that underlie several aspects of destruction complex function are poorly understood, particularly the role of APC. Here we review the molecular mechanisms of destruction complex function and discuss several potential roles of APC in β-catenin destruction. PMID:23169527

  10. 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.

  11. 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

  12. 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.

  13. Predicting the velocity and azimuth of fragments generated by the range destruction or random failure of rocket casings and tankage

    NASA Technical Reports Server (NTRS)

    Eck, Marshall; Mukunda, Meera

    1988-01-01

    A calculational method is described which provides a powerful tool for predicting solid rocket motor (SRM) casing and liquid rocket tankage fragmentation response. The approach properly partitions the available impulse to each major system-mass component. It uses the Pisces code developed by Physics International to couple the forces generated by an Eulerian-modeled gas flow field to a Lagrangian-modeled fuel and casing system. The details of the predictive analytical modeling process and the development of normalized relations for momentum partition as a function of SRM burn time and initial geometry are discussed. Methods for applying similar modeling techniques to liquid-tankage-overpressure failures are also discussed. Good agreement between predictions and observations are obtained for five specific events.

  14. Are Zebra Carbonates Formed During Seismic Events?

    NASA Astrophysics Data System (ADS)

    Urai, J. L.; Holland, M.; Schoenherr, J.; Miller, S.

    2006-12-01

    Zebra carbonates are characterized by subparallel, rhythmic, mm-scale banding of host rock and vein. Their genesis has been interpreted by different authors as primary sedimentary structure, metasomatic infiltration or mechanical fragmentation followed by deposition of vein minerals. We studied zebra carbonates in the damage zones of normal faults formed during the drainage of an overpressure cell at about 7 km depth, in outcrops on Jebel Shams, Oman Mountains. They show a distinct pattern of mm-scale regularly spaced calcite veins in the dark grey, fine-grained carbonate host rocks, often connected laterally to a wide mode I fracture filled by a single calcite vein several cm thick. Veins in the zebra carbonates are filled with blocky crystals, indicating that the fractures remained open after their formation to allow crystal growth from a supersaturated fluid. Microstructures show no evidence of repeated crack-seal events and we conclude that all the veins in one zebra were formed simultaneously. The very high density of closely-spaced and simultaneously formed fractures indicates that they were formed very rapid loading, producing fracture densities much higher than expected during slow deformation. On the other hand, the high- density fracture systems formed during explosive fracturing in dry rocks are much less regularly spaced. We hypothesize that the zebra carbonates were formed by rapid loading during faulting in highly overpressured carbonates, in places where coseismic rupture leads to a significant fluid pressure drop in dilatant jogs. The permeability of the matrix carbonate leads to drop in pore-fluid pressure close to the crack walls. This makes the host rock stronger close to the crack wall, so that the next fracture will preferentially propagate into the matrix away from the walls of the existing fracture. This process can lead to a more regularly spaced pattern of veins. Further work on zebra carbonates could provide a new tool to distinguish

  15. 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.

  16. Evaluation of Damage in Steels Subjected to Exploitation Loading - Destructive and Non-Destructive Methods

    NASA Astrophysics Data System (ADS)

    Kowalewski, Zbigniew L.; Mackiewicz, Sławomir; Szelążek, Jacek; Pietrzak, Krystyna; Augustyniak, Bolesław

    Damage due to creep and plastic flow is assessed using destructive and non-destructive methods in steels (40HNMA and P91). In the destructive methods the standard tension tests were carried out after prestraining and variations of the selected tension parameters were taken into account for damage identification. In order to assess a damage development during the creep and plastic deformation the tests for both steels were interrupted for a range of the selected strain magnitudes. The ultrasonic and magnetic techniques were used as the non-destructive methods for damage evaluation. The last step of the experimental programme contained microscopic observations. A very promising correlation between parameters of methods for damage development evaluation was achieved. It is well proved for the ultimate tensile stress and birefringence coefficient.

  17. 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.

  18. Energetics of mechanical destruction of middle radicals

    NASA Astrophysics Data System (ADS)

    Kvachadze, N. G.; Tomashevskii, E. E.; Zhizhenkov, V. V.

    2015-11-01

    The breaking strain of a model fragment of a middle radical in a rigid polymer matrix has been calculated. The force and energy characteristics of the destruction of the radical and the formation of double bonds have been estimated. The dissociation energy and the strength of Cβ-Cγ bonds for trans- and gaucheconformers of radicals have been determined. It has been established that the probability of breaking of the β bonds essentially depends of the conformation structure of the macroradicals.

  19. 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.

  20. Detailed seal analysis, Lower Cretaceous rocks of the North Sinai basin, Egypt: Effects on hydrocarbon migration and accumulation in overpressured regimes

    SciTech Connect

    Nashaat, M. )

    1991-03-01

    The filling mechanism of petroleum traps in the North Sinai basin has been studied, taking into account the area's maturation history, the hydrodynamic parameters, and the seal efficiencies. The purpose of this study was to ascertain whether or not sizeable accumulations of hydrocarbons could be expected and to investigate the origin of the oil discovered to date. Formation pressure regimes in the North Sinai basin include highly overpressured reservoirs with undercompacted shale, starting at relatively shallow depths. In particular, the deeper closed hydraulic systems usually exhibit abnormally pressured regimes in individual fluid compartments. The pressure regimes are separated from each other by seals that are of particular interest to explorationists, as they frequently support oil and gas pools. The fracture pressures as well as the formation pore pressures were used together in some wells to evaluate seal quality. This detailed seal analysis has identified many regional seals and pressure compartments and their lateral and areal extent. These seals seem to control the hydrodynamic regime in the underlying permeable Lower Cretaceous reservoirs, and along with source maturation strongly affect the migration of hydrocarbons from source rocks and their accumulation in reservoirs. The water chemistry of the undercompacted sediments and overpressured reservoirs agrees with the different hydrodynamic systems mapped. Water chemistry zones clearly define different hydraulic systems. Originally, they are the freshwater aquifer of Lower Cretaceous overlain by higher salinity formations.

  1. DESTRUCTION OF CYANIDE IN WASTEWATERS: REVIEW AND EVALUATION

    EPA Science Inventory

    The report presents a review of known cyanide destruction technologies with respect to applicability, feasibility, effectiveness and cost. Particular emphasis was placed on the destruction of complex cyanides. Laboratory studies were conducted to evaluate a photocatalytic process...

  2. 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

  3. Tobacco smoking and chronic destructive periodontal disease.

    PubMed

    Bergström, Jan

    2004-09-01

    Tobacco smoking is the main risk factor associated with chronic destructive periodontal disease. No other known factor can match the strength of smoking in causing harm to the periodontium. The harmful effects manifest themselves by interfering with vascular and immunologic reactions, as well as by undermining the supportive functions of the periodontal tissues. The typical characteristic of smoking-associated periodontal disease is the destruction of the supporting tissues of the teeth, with the ensuing clinical symptoms of bone loss, attachment loss, pocket formation, and eventually tooth loss. A review of the international literature that has accumulated over the past 20 years offers convincing evidence that smokers exhibit greater bone loss and attachment loss, as well as more pronounced frequencies of periodontal pockets, than non-smokers do. In addition, tooth loss is more extensive in smokers. Smoking, thus, considerably increases the risk for destructive periodontal disease. Depending on the definition of disease and the exposure to smoking, the risk is 5- to 20-fold elevated for a smoker compared to a never-smoker. For a smoker exposed to heavy long-life smoking, the risk of attracting destructive periodontal disease is equivalent to that of attracting lung cancer. The outcome of periodontal treatment is less favorable or even unfavorable in smokers. Although long-term studies are rare, available studies unanimously agree that treatment failures and relapse of disease are predominantly seen in smokers. This contention is valid irrespective of treatment modality, suggesting that smoking will interfere with an expected normal outcome following commonplace periodontal therapies. The majority of available studies agree that the subgingival microflora of smokers and non-smokers are no different given other conditions. As a consequence, the elevated morbidity in smokers does not depend on particular microflora. The mechanisms behind the destructive effects of

  4. 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…

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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.``