WorldWideScience

Sample records for blowouts

  1. Offshore Blowouts, Causes and Trends

    Energy Technology Data Exchange (ETDEWEB)

    Holand, P.

    1996-02-01

    The main objective of this doctoral thesis was to establish an improved design basis for offshore installations with respect to blowout risk analyses. The following sub objectives are defined: (1) Establish an offshore blowout database suitable for risk analyses, (2) Compare the blowout risk related to loss of lives with the total offshore risk and risk in other industries, (3) Analyse blowouts with respect to parameters that are important to describe and quantify blowout risk that has been experienced to be able to answer several questions such as under what operations have blowouts occurred, direct causes, frequency of occurrence etc., (4) Analyse blowouts with respect to trends. The research strategy applied includes elements from both survey strategy and case study strategy. The data are systematized in the form of a new database developed from the MARINTEK database. Most blowouts in the analysed period occurred during drilling operations. Shallow gas blowouts were more frequent than deep blowouts and workover blowouts occurred more often than deep development drilling blowouts. Relatively few blowouts occurred during completion, wireline and normal production activities. No significant trend in blowout occurrences as a function of time could be observed, except for completion blowouts that showed a significantly decreasing trend. But there were trends regarding some important parameters for risk analyses, e.g. the ignition probability has decreased and diverter systems have improved. Only 3.5% of the fatalities occurred because of blowouts. 106 refs., 51 figs., 55 tabs.

  2. Blowout preventer; Utblaasningssikring

    Energy Technology Data Exchange (ETDEWEB)

    Askeland, R.; Larsen, V.

    1997-06-16

    the invention relates to a blowout preventer particularly for use in drilling bore hole sections near the sea bed. It is adapted to prevent blowout of shallow gas in the bore hole. It consists of one annular flexibly expansible and contractible packing element, which by radially directed expansion is adapted to rest in a sealed condition against the wall of the bore hole and close the passage through the annular space of the same. The preventer comprises an inner sleeve element being limited telescopic displaceable in relation to the outer housing of the preventer and being spring loaded towards extended telescopic position when it is subjected to extra weight loading, and means which in the relative contracted telescopic position of the sleeve element and outer housing is adapted to close the passage through the inner cavity of the blowout preventer and established liquid connection to the packing element or elements for inflation thereof. 13 figs.

  3. Blowouts are key to the survival of blowout penstemon

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This newspaper article summarizes ongoing conservation and management of blowout penstemon on federal land. The occurrence of this unique plant has never been...

  4. A blowout preventer

    Energy Technology Data Exchange (ETDEWEB)

    Grigor' yev, N.I.; Khayrullin, B.Yu.; Nomin, V.I.; Ukdov, I.A.

    1983-01-01

    A blowout preventer is proposed which contains a body, blocks with rods, tops, hydraulic cylinders, spindles linked with the rods of the hydraulic cylinders and with the blocks which are installed in spindle stops and locking devices. To ensure the capability of backing up the hydraulic drive with a manual drive when using the preventer with traverse linked hydraulic cylinders installed on the body parallel to the axis of movement of the blocks, the spindles are linked with the rods of the blocks by a telescopic helical connection, are connected with the traverses with the capability of turning and are made with beads for interacting with the traverses when the preventer is closed. The stops are equal in length to the travel of the block for locking the spindles during opening of the preventer.

  5. Blowout bifurcation of chaotic saddles

    Directory of Open Access Journals (Sweden)

    Tomasz Kapitaniak

    1999-01-01

    Full Text Available Chaotic saddles are nonattracting dynamical invariant sets that can lead to a variety of physical phenomena. We describe the blowout bifurcation of chaotic saddles located in the symmetric invariant manifold of coupled systems and discuss dynamical phenomena associated with this bifurcation.

  6. 16 CFR 1507.6 - Burnout and blowout.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Burnout and blowout. 1507.6 Section 1507.6... FIREWORKS DEVICES § 1507.6 Burnout and blowout. The pyrotechnic chamber in fireworks devices shall be constructed in a manner to allow functioning in a normal manner without burnout or blowout....

  7. Surgical Timing of the Orbital "Blowout" Fracture

    DEFF Research Database (Denmark)

    Damgaard, Olaf Ehlers; Larsen, Christian Grønhøj; Felding, Ulrik Ascanius;

    2016-01-01

    OBJECTIVE: The orbital blowout fracture is a common facial injury, carrying with it a risk of visual impairment and undesirable cosmetic results unless treated properly. Optimal timing of the surgical treatment is still a matter of debate. We set out to determine whether a meta-analysis would bring...... us closer to an answer to this question. DATA SOURCES: PubMed, EMBASE, Web of Science, and the Cochrane Library were searched from January 1980 to August 2014. We applied the following inclusion criteria: isolated blowout fractures, presenting early and late surgery groups (14 days...

  8. Gas Well Blowout Kills 243 People

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    @@ At least 243 people have been killed and scores of others poisoned in a devastating blowout at a natural gas field in Southwest China's Chongqing municipality on December 24. The accident happened at the Chuandongbei gas field in Kaixian county of Chongqing municipality.

  9. 30 CFR 250.515 - Blowout prevention equipment.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Blowout prevention equipment. 250.515 Section 250.515 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS... Blowout prevention equipment. (a) The BOP system and system components and related well-control...

  10. Gastric blow-out: komplikation efter fedmekirurgi

    DEFF Research Database (Denmark)

    Torrens, Ayoe Sabrina; Born, Pernille Wolder; Naver, Lars

    2009-01-01

    Laparoscopic gastric bypass is the most common type of surgery for morbid obesity in Denmark. The most frequent late complications after gastric bypass are ulcer, internal hernia and stenosis. Two cases of stenosis of the bileopancreatic limb with gastric blow-out are described. Urgent diagnosis...... with computed tomography and acute surgical treatment is vital as the complication can lead to gastric necrosis, pancreatitis, biliary stasis, sepsis and multi-organ failure within a very short time. Prompt contact to specialized surgeons is advocated. Udgivelsesdato: 2009-Nov...

  11. CT findings of orbital blow-out fracture

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jeong Yeol; Park, Jun Kyun; Lim, Woo Young; Rho, Kwang Suk; Ko, Yong Suk; Kim, Young Chul; Oh, Jae Hee [Chosun Univ., Kwangju (Korea, Republic of). Coll. of Medicine

    1998-02-01

    To evaluate the usefulness and radiologic findings of CT in the diagnosis of orbital blow-out fracture. Forty-four patients with orbital blow-out fractures diagnosed by clinical findings and CT were evaluated retrospectively. On CT images, we evaluated the site and frequency of fracture, herniation of orbital fat, extraocular muscle abnormality, intraorbital hematoma, and intrasinus hemorrhage. CT is a useful diagnostic modality for the evaluation of orbital blow-out fracture and associated soft tissue abnormalities. (author). 16 refs., 1 tab., 2 figs.

  12. Determination of blowout pressures during electron beam welding

    Energy Technology Data Exchange (ETDEWEB)

    Sunwoo, A

    1999-04-01

    During electron beam (EB) welding of developmental units, weld blowouts occurred. It is well documented that the presence of moisture causes the weld blowout. The detrimental effects of water vapor on the weld are experimentally proven [l]. The availability of water vapor in the melt increases the onset and severity of blowout and porosity. Because water vapor is insoluble in the molten metal, it will consequently form either bubbles or boil. On the other hand, hydrogen will react with other impurities present in the melt to form insoluble gas bubbles, which most likely will be entrapped in the fusion zone as porosity. This study attempts to answer the question of what is the critical weld blowout pressure, and to compare the experimental results to the estimated pressure values, so that validated calculations could be extended to other weld configurations.

  13. Impending Carotid Blowout Stabilization Using an LT-D Tube

    Directory of Open Access Journals (Sweden)

    G. Desuter

    2014-01-01

    Full Text Available Adequate stabilization of a patient presenting with a carotid blowout is one of the most challenging issues an on-call ENT surgeon can be confronted with. Reducing the bleeding and securing the airway are essential before more definitive management. We present the case of a 72-year-old patient with head and neck cancer who arrived at the emergency room with a carotid blowout and who was successfully stabilized using a King LT-D ventilation tube.

  14. Natural marine seepage blowout: Contribution to atmospheric methane

    OpenAIRE

    2006-01-01

    The release of methane sequestered within deep-sea methane hydrates is postulated as a mechanism for abrupt climate change; however, whether emitted seabed methane reaches the atmosphere is debatable. We observed methane emissions for a blowout from a shallow (22 m) hydrocarbon seep. The emission from the blowout was determined from atmospheric plume measurements. Simulations suggest a 1.1% gas loss to dissolution compared to ∼ 10% loss for a typical low-flux bubble plume. Transfer to the atm...

  15. Emergency operation of a subsea drilling blowout preventer

    OpenAIRE

    Kozel, Kiryl

    2015-01-01

    The world-scale disaster in the Gulf of Mexico on 20 April 2011 drew the attention of the authorities and oil and gas companies to the reliability of the blowout preventer systems. The efficiency of emergency preparedness to operate such systems was also in the spotlight due to several unsuccessful attempts to operate during the accident. Generally, there are three main methods and five sub-methods, which allow controlling the blowout preventer systems when the primary control system is not a...

  16. Dichotomy of Solar Coronal Jets: Standard Jets and Blowout Jets

    Science.gov (United States)

    Moore, R. L.; Cirtain, J. W.; Sterling, A. C.; Falconer, D. A.

    2010-01-01

    By examining many X-ray jets in Hinode/XRT coronal X-ray movies of the polar coronal holes, we found that there is a dichotomy of polar X-ray jets. About two thirds fit the standard reconnection picture for coronal jets, and about one third are another type. We present observations indicating that the non-standard jets are counterparts of erupting-loop H alpha macrospicules, jets in which the jet-base magnetic arch undergoes a miniature version of the blowout eruptions that produce major CMEs. From the coronal X-ray movies we present in detail two typical standard X-ray jets and two typical blowout X-ray jets that were also caught in He II 304 Angstrom snapshots from STEREO/EUVI. The distinguishing features of blowout X-ray jets are (1) X-ray brightening inside the base arch in addition to the outside bright point that standard jets have, (2) blowout eruption of the base arch's core field, often carrying a filament of cool (T 10(exp 4) - 10(exp 5) K) plasma, and (3) an extra jet-spire strand rooted close to the bright point. We present cartoons showing how reconnection during blowout eruption of the base arch could produce the observed features of blowout X-ray jets. We infer that (1) the standard-jet/blowout-jet dichotomy of coronal jets results from the dichotomy of base arches that do not have and base arches that do have enough shear and twist to erupt open, and (2) there is a large class of spicules that are standard jets and a comparably large class of spicules that are blowout jets.

  17. Stability Control of Vehicle Emergency Braking with Tire Blowout

    Directory of Open Access Journals (Sweden)

    Qingzhang Chen

    2014-01-01

    Full Text Available For the stability control and slowing down the vehicle to a safe speed after tire failure, an emergency automatic braking system with independent intellectual property is developed. After the system has received a signal of tire blowout, the automatic braking mode of the vehicle is determined according to the position of the failure tire and the motion state of vehicle, and a control strategy for resisting tire blowout additional yaw torque and deceleration is designed to slow down vehicle to a safe speed in an expected trajectory. The simulating test system is also designed, and the testing results show that the vehicle can be quickly stabilized and kept in the original track after tire blowout with the emergency braking system described in the paper.

  18. 30 CFR 250.1624 - Blowout prevention equipment.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Blowout prevention equipment. 250.1624 Section 250.1624 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND... prevention equipment. (a) The BOP system and system components and related well-control equipment shall...

  19. On the ongoing multiple blowout in NGC 604

    CERN Document Server

    Tenorio-Tagle, G; Pérez, E; Maíz-Appelániz, J; Medina-Tanco, G A

    2000-01-01

    Several facts regarding the structure of NGC 604 are examined here. The three main cavities, produced by the mechanical energy from massive stars which in NGC 604 are spread over a volume of 10$^6$ pc$^3$, are shown here to be undergoing blowout into the halo of M33. High resolution long slit spectroscopy is used to track the impact from massive stars while HST archive data is used to display the asymmetry of the nebula. NGC 604 is found to be a collection of photoionized filaments and sections of shells in direct contact with the thermalized matter ejected by massive stars. The multiple blowout events presently drain the energy injected by massive stars and thus the densest photoionized gas is found almost at rest and is expected to suffer a slow evolution.

  20. Sandy grassland blowouts in Hulunbuir,northeast China:geomorphology,distribution,and causes

    Institute of Scientific and Technical Information of China (English)

    ZHANG Altan MunkhDalai; FENG Zongwei; WANG Xiaoke; SUN Hongwei; ZHAO Jiaming; U Hurlee

    2007-01-01

    A sandy grassland blowout consists of an aeolian depression formed in top soil and the underlying sand deposit underlie,and the adjoining redeposit of sand derived from the depression. Research based on field survey and topographic mapping combined with aerophotograph interpretation reveals that: (1) All the three sand land tracts in Hulunbuir Grasslands are composed of blowout depressions and adjoining dunes, with interlaying remnants of sandy grasslands as background; (2) blowout depressions and their adjoining dunes can be classified according to their morphometric characteristics, development stages, and initiating factors; (3) blowouts develop mostly in the upper parts of sidelong aweather and sunward slopes inclining southwestward when west wind prevails; (4) initiation of blowouts is closely related with the coupling of extreme droughts and wide spread intense human disturbance to the fragile topsoil layer. The investigations indicate that key factors to prevent desertification are to protect grassland vegetation and topsoil.

  1. Carotid artery blowout producing massive hematemesis in the emergency department

    Institute of Scientific and Technical Information of China (English)

    Harrison K Borno; Richard J Menendez; John C Chaloupka; Michael T Dalley; David A Farcy

    2016-01-01

    Carotid blowout syndrome (CBS) is a rare and fatal complication which arises from patients who have been treated for head and neck cancer. The incidence of CBS is rare and not commonly seen by emergency physicians. We review a case of a 68-year-old woman with a history of laryngectomy and chemo-radiation therapy presenting with massive oral bleeding and hypotension. Her course and treatments are highlighted, literature referring to CBS are described and we reintroduce the approach of managing such a patient in the emergency department.

  2. Retrobulbar Hematoma in Blow-Out Fracture after Open Reduction

    Directory of Open Access Journals (Sweden)

    Ji Seon Cheon

    2013-07-01

    Full Text Available Retrobulbar hemorrhage, especially when associated with visual loss, is a rare but significant complication after facial bone reconstruction. In this article, two cases of retrobulbar hematoma after surgical repair of blow-out fracture are reported. In one patient, permanent loss of vision was involved, but with the other patient, we were able to prevent this by performing immediate decompression after definite diagnosis. We present our clinical experience with regard to the treatment process and method for prevention of retrobulbar hematoma using a scalp vein set tube and a negative pressure drainage system.

  3. Carotid artery blowout producing massive hematemesis in the emergency department

    Directory of Open Access Journals (Sweden)

    Harrison K. Borno

    2016-03-01

    Full Text Available Carotid blowout syndrome (CBS is a rare and fatal complication which arises from patients who have been treated for head and neck cancer. The incidence of CBS is rare and not commonly seen by emergency physicians. We review a case of a 68-year-old woman with a history of laryngectomy and chemo-radiation therapy presenting with massive oral bleeding and hypotension. Her course and treatments are highlighted, literature referring to CBS are described and we reintroduce the approach of managing such a patient in the emergency department.

  4. Considerations for the Management of Medial Orbital Wall Blowout Fracture

    Science.gov (United States)

    Park, Youngsoo; Chung, Kyu Jin

    2016-01-01

    Recently, diagnoses of and operations for medial orbital blowout fracture have increased because of the development of imaging technology. In this article, the authors review the literature, and overview the accumulated knowledge about the orbital anatomy, fracture mechanisms, surgical approaches, reconstruction materials, and surgical methods. In terms of surgical approaches, transcaruncular, transcutaneous, and transnasal endoscopic approaches are discussed. Reconstruction methods including onlay covering, inlay implantation, and repositioning methods are also discussed. Consideration and understanding of these should lead to more optimal outcomes. PMID:27218019

  5. Interaction of hydraulic and buckling mechanisms in blowout fractures.

    Science.gov (United States)

    Nagasao, Tomohisa; Miyamoto, Junpei; Jiang, Hua; Tamaki, Tamotsu; Kaneko, Tsuyoshi

    2010-04-01

    The etiology of blowout fractures is generally attributed to 2 mechanisms--increase in the pressure of the orbital contents (the hydraulic mechanism) and direct transmission of impacts on the orbital walls (the buckling mechanism). The present study aims to elucidate whether or not an interaction exists between these 2 mechanisms. We performed a simulation experiment using 10 Computer-Aided-Design skull models. We applied destructive energy to the orbits of the 10 models in 3 different ways. First, to simulate pure hydraulic mechanism, energy was applied solely on the internal walls of the orbit. Second, to simulate pure buckling mechanism, energy was applied solely on the inferior rim of the orbit. Third, to simulate the combined effect of the hydraulic and buckling mechanisms, energy was applied both on the internal wall of the orbit and inferior rim of the orbit. After applying the energy, we calculated the areas of the regions where fracture occurred in the models. Thereafter, we compared the areas among the 3 energy application patterns. When the hydraulic and buckling mechanisms work simultaneously, fracture occurs on wider areas of the orbital walls than when each of these mechanisms works separately. The hydraulic and buckling mechanisms interact, enhancing each other's effect. This information should be taken into consideration when we examine patients in whom blowout fracture is suspected.

  6. Meso-scale aeolian transport of beach sediment via dune blowout pathways within a linear foredune

    Science.gov (United States)

    O'Keeffe, Nicholas; Delgado-Fernandez, Irene; Jackson, Derek; Aplin, Paul; Marston, Christopher

    2016-04-01

    The evolution of coastal foredunes is largely controlled by sediment exchanges between the geomorphic sub-units of the nearshore, beach, foredune and dune field. Although blowouts are widely recognised as efficient sediment transport pathways, both event-scale and meso-scale quantification of their utility in transferring beach sediments landwards is limited. Foredunes characterised by multiple blowouts may be more susceptible to coastline retreat through the enhanced landwards transport of beach or foredune sediments. To date, a key constraint for investigations of such scenarios has been the absence of accurate blowout sediment transport records. Here we use the Sefton coast in north-west England as a study area where an unprecedented temporal coverage of LIDAR data is available between 1999 and 2015. Additionally, an extensive set of aerial photography also exists, dating back to 1945 allowing comparison of blowout frequency and magnitude together with the alongshore limits of coastline retreat. Digital terrain models are derived for each year that LIDAR data is available. Informed by LIDAR based topography and areas of bare sand (aerial photos) terrain models have been created containing individual blowouts. Differentials in 'z' values between each terrain model of each available year has identified topographic change and total levels of transport. Preliminary results have confirmed the importance of blowouts in transporting beach or foredune sediment landwards and thus potentially promoting coastline retreat. Repetition of processes across a larger number of blowout topographies will allow better identification of individual blowouts for 'event' scale field investigations to examine spatial and temporal variability of beach sediment transport via blowouts routes.

  7. Ethmoid sinus osteoma associated with blow-out fracture.

    Science.gov (United States)

    Kim, Young-Jin; Kim, Dong-Yeon; Jun, Young-Joon; Seo, Byung-Chul

    2012-03-01

    Osteoma is a benign tumor that is composed of compact or cancellous bone. It is the most common benign neoplasm of the paranasal sinus, and ethmoid sinuses are the second most common sites of paranasal sinus osteoma. The symptoms of ethmoid sinus osteoma can give rise to various kinds and extent of symptoms. In symptomatic cases, surgical management is necessary, but appropriate surgical approach to the ethmoid sinus is not clearly established. We describe 2 male patients with a diagnosis of blow-out fractures after trauma; ethmoid sinus osteoma on preoperative computed tomography scans was coincidentally found, and the surgical correction was done simultaneously. The purpose of this article was to present the successful surgical removal of ethmoid osteoma through lamina papyracea and transcaruncular approach, resulting in both successful surgical correction and good cosmetic outcome.

  8. The short bunch blow-out regime in RF photoinjectors

    Energy Technology Data Exchange (ETDEWEB)

    Serafini, L. [INFN and Universita di Milano, Via Celoria 16, 20133Milano (Italy)

    1997-06-01

    A new beam dynamics regime of RF Photoinjectors is presented here, dealing with a violent bunch elongation under the action of longitudinal space charge forces. It is shown that such a blow-out expansion of the electron bunch can lead to highly linear behaviors of both the longitudinal and the transverse space charge field, a well known prerequisite to achieve minimum emittance dilution in photoinjectors. If operated in the ultra-short pancake-like bunch regime, such an effect can be very beneficial to the emittance correction mechanism, making it effective also for ultra-short pancake like bunches. The anticipated performances are presented: kA peak current beams can be generated directly out of the photoinjector (10 to 20 MeV exit energy) with rms normalized emittances below 1mm{center_dot}mrad. {copyright} {ital 1997 American Institute of Physics.}

  9. Morphology and Sediment Transport Dynamics of a Trough-Blowout Dune, Bodega Marine Reserve, Northern California

    Science.gov (United States)

    Jorgenson, D.; Dunleavy, C. J.; Smith, M. E.

    2014-12-01

    Blowout dunes are a primary mechanism for transporting sand within vegetated coastal dune systems. Understanding the fine-scale variation in sediment transport within these systems is critical to predicting their formation and migration. Previous investigations of a coastal dune system located at the Bodega Marine Reserve, on the Sonoma Coast of Northern California have indicated that aeolian sand flux in unvegetated sand is ~450x greater than in vegetated areas. To better understand sand flux and its relationship with wind speed, direction and precipitation, we deployed an array of 12 sand traps within a single blowout area adjacent to the BOON marine climatology station. The blowout is trough- shaped, approximately 50 meters long and 15 meters wide. Its main 'fairway' is 5-10 meters below the surrounding beach grass (Ammophila)-covered land surface. Surface sediment within the blowout is fine-grained to granule-sized lithic to sub-lithic sand, and is coarsest in the center. Dune sediment in the Bodega Marine Reserve has been transported by aeolian processes from Salmon Creek Beach to the NW. Within the blowout, typical bedforms include 15-25 cm-wavelength, ~10 cm high sinuous to lingoid ripples arranged perpendicularly to the dominant wind direction (~280 degrees). An 8-10 meter-high mound at the downwind end has accumulated due to the trapping of sand flux by vegetation. Sediment flux across the studied blowout was sampled monthly over a 10-month period of 2013-2014. Sand traps were constructed using modified PVC cylinders, and are 0.5 meter high and 0.3 meter in diameter, with a 0.74-micron mesh screen. Based on measured sand flux, the sites can be categorized into three groups-axial, medial, and peripheral. Rates increase downwind within the blowout. Inter-site sand flux variability within unvegetated locations of the blowout is greater than two orders of magnitude. Axial sites, which experience the greatest sand flux, occur on the edge of the blowout adjacent

  10. Three-dimensional æolian dynamics within a bowl blowout during offshore winds: Greenwich Dunes, Prince Edward Island, Canada

    Science.gov (United States)

    Hesp, Patrick A.; Walker, Ian J.

    2012-01-01

    This paper examines the æolian dynamics of a deep bowl blowout within the foredune of the Greenwich Dunes, on the northeastern shore or Prince Edward Island, Canada. Masts of cup anemometers and sonic anemometers were utilized to measure flow velocities and directions during a strong regional ESE (offshore) wind event. The flow across the blowout immediately separated at the upwind rim crest, and within the blowout was strongly reversed. High, negative vertical flows occurred down the downwind (but seaward) vertical scarp which projected into the separation envelope and topographically forced flow back into the blowout. A pronounced, accelerated jet flow existed near the surface across the blowout basin, and the flow exhibited a complex, anti-clockwise structure with the near-surface flow following the contours around the blowout basin and lower slopes. Significant æolian sediment transport occurred across the whole bowl basin and sediment was delivered by saltation and suspension out the blowout to the east. This study demonstrates that strong offshore winds produce pronounced topographically forced flow steering, separation, reversal, and more complex three-dimensional motions within a bowl blowout, and that such winds within a bowl blowout play a notable role in transporting sediment within and beyond deep topographic hollows in the foredune.

  11. Development of an automatic subsea blowout preventer stack control system using PLC based SCADA.

    Science.gov (United States)

    Cai, Baoping; Liu, Yonghong; Liu, Zengkai; Wang, Fei; Tian, Xiaojie; Zhang, Yanzhen

    2012-01-01

    An extremely reliable remote control system for subsea blowout preventer stack is developed based on the off-the-shelf triple modular redundancy system. To meet a high reliability requirement, various redundancy techniques such as controller redundancy, bus redundancy and network redundancy are used to design the system hardware architecture. The control logic, human-machine interface graphical design and redundant databases are developed by using the off-the-shelf software. A series of experiments were performed in laboratory to test the subsea blowout preventer stack control system. The results showed that the tested subsea blowout preventer functions could be executed successfully. For the faults of programmable logic controllers, discrete input groups and analog input groups, the control system could give correct alarms in the human-machine interface.

  12. Global properties of symmetric competition models with riddling and blowout phenomena

    Directory of Open Access Journals (Sweden)

    Giant-italo Bischi

    2000-01-01

    Full Text Available In this paper the problem of chaos synchronization, and the related phenomena of riddling, blowout and on–off intermittency, are considered for discrete time competition models with identical competitors. The global properties which determine the different effects of riddling and blowout bifurcations are studied by the method of critical curves, a tool for the study of the global dynamical properties of two-dimensional noninvertible maps. These techniques are applied to the study of a dynamic market-share competition model.

  13. 30 CFR 250.516 - Blowout preventer system tests, inspections, and maintenance.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Blowout preventer system tests, inspections, and maintenance. 250.516 Section 250.516 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and...

  14. 30 CFR 250.616 - Blowout preventer system testing, records, and drills.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Blowout preventer system testing, records, and drills. 250.616 Section 250.616 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas...

  15. Blow-out of nonpremixed turbulent jet flames at sub-atmospheric pressures

    KAUST Repository

    Wang, Qiang

    2016-12-09

    Blow-out limits of nonpremixed turbulent jet flames in quiescent air at sub-atmospheric pressures (50–100 kPa) were studied experimentally using propane fuel with nozzle diameters ranging 0.8–4 mm. Results showed that the fuel jet velocity at blow-out limit increased with increasing ambient pressure and nozzle diameter. A Damköhler (Da) number based model was adopted, defined as the ratio of characteristic mixing time and characteristic reaction time, to include the effect of pressure considering the variations in laminar burning velocity and thermal diffusivity with pressure. The critical lift-off height at blow-out, representing a characteristic length scale for mixing, had a linear relationship with the theoretically predicted stoichiometric location along the jet axis, which had a weak dependence on ambient pressure. The characteristic mixing time (critical lift-off height divided by jet velocity) adjusted to the characteristic reaction time such that the critical Damköhler at blow-out conditions maintained a constant value when varying the ambient pressure.

  16. Straightforward factors for predicting the prognosis of blow-out fractures.

    Science.gov (United States)

    Higashino, Takuya; Hirabayashi, Shinichi; Eguchi, Tomoaki; Kato, Yuki

    2011-07-01

    In blow-out fractures, some nonoperative cases have a poor outcome, and a method for accurate prognosis is required. To address this need, we retrospectively reviewed blow-out fractures presenting at Teikyo University Hospital between July 2004 and May 2007 and conducted a survey regarding diplopia and enophthalmos for nonoperative cases. Computed tomographic scan findings were divided according to fracture width and the degree of protrusion of the inferior rectus muscle into the maxillary sinus. We had 106 patients presenting with blow-out fractures, and 89 patients had been treated nonoperatively. In medial orbital wall fractures, no patient had diplopia, and 1 patient had enophthalmos after nonoperative treatment. In punched-out orbital floor fractures, all cases had diplopia when the fracture width was less than half the diameter of the globe, and the protrusion of the inferior rectus muscle into the maxillary sinus was half or more of its section. Even if the fracture width was less than half the diameter of the globe, 2 of 3 patients had enophthalmos when the protrusion of the inferior rectus muscle into the maxillary sinus was half or more of its section. Among the linear orbital floor fractures, 1 case required an emergency operation. We suggest a new algorithm for treatment of blow-out fractures based on computed tomographic scan findings that can also contribute to making a prognosis.

  17. X-rays from superbubbles in the large magellanic cloud; 4, the blowout structure of N44

    CERN Document Server

    Magnier, E A; Hwang, U; Smith, R C; Magnier, Eugene A; Chu, You Hua; Hwang, Una; Smith, R Chris

    1996-01-01

    We have used optical echelle spectra along with ROSAT and ASCA X-ray spectra to test the hypothesis that the southern portion of the N44 X-ray bright region is the result of a blowout structure. Three pieces of evidence now support this conclusion. First, the filamentary optical morphology corresponding with the location of the X-ray bright South Bar suggests the blowout description (Chu et al 1993). Second, optical echelle spectra show evidence of high velocity (~90 km/sec) gas in the region of the blowout. Third, X-ray spectral fits show a lower temperature for the South Bar than the main superbubble region of Shell 1. Such a blowout can affect the evolution of the superbubble and explain some of the discrepancy discussed by Oey & Massey (1995) between the observed shell diameter and the diameter predicted on the basis of the stellar content and Weaver et al.'s (1977) pressure-driven bubble model.

  18. Helical Blowout Jets in the Sun: Untwisting and Propagation of Waves

    CERN Document Server

    Lee, E J; Hood, A W

    2014-01-01

    We report on numerical experiment of the recurrent onset of helical "blowout" jets in an emerging flux region (EFR). We find that these jets are running with velocities of $\\sim 100-250\\,\\mathrm{kms^{-1}}$ and they transfer a vast amount of heavy plasma into the outer solar atmosphere. During their emission, they undergo an untwisting motion as a result of reconnection between the twisted emerging and the non-twisted pre-existing magnetic field in the solar atmosphere. For the first time in the context of blowout jets, we provide a direct evidence that their untwisting motion is associated with the propagation of torsional Alfv\\'en waves in the corona.

  19. Airflow and sediment movement within an inland blowout in Hulun Buir sandy grassland, Inner Mongolia, China

    Science.gov (United States)

    Sun, Yu; Hasi, Eerdun; Liu, Meiping; Du, Huishi; Guan, Chao; Tao, Binbin

    2016-09-01

    We measured wind flows and sediment transport rates through a blowout in Hulun Buir grassland, Inner Mongolia. Topography and the angle of incidence between the approaching wind and the blowout long-axis significantly affected the air flow. Flow separated and decelerated at the western wall and accelerated towards the east, until maximum wind speed occurred at the top of the depositional lobe, and then decelerated on the lee side. When airflow emerged on the eastern wall, resultant directions were always NW. When winds approached from directions within 17.5° of the blowout axis, both the northwestern and southwestern walls developed turbulent flow, and significant topographic steering occurred. The deceleration zone expanded eastwards from 10.3 to 12.8 m from the western rim. When the wind direction was more oblique than 17.5°, turbulent flow at the southwestern wall disappeared. 'S-shaped' flow intensified, causing more pronounced steering at the bottom, but topographic steering elsewhere was reduced, and the boundary of the deceleration moved to 10 m from the western rim. Minor sediment deposition occurred on the western wall, while other parts were eroded; maximum sediment transport occurred at the top of the depositional lobe. The approaching wind speed affected the sediment transport rate more than the direction; and spatial variability in sediment transport reflected differences in compaction, vegetation coverage, slope, aspect, and upwind sediment availability, resulting in asymmetrical development. Overall, flow-form interactions governed the flow structures and controlled the evolution of the blowout via sediment transport.

  20. Blowout Jets: Hinode X-Ray Jets that Don't Fit the Standard Model

    Science.gov (United States)

    Moore, Ronald L.; Cirtain, Jonathan W.; Sterling, Alphonse C.; Falconer, David A.

    2010-01-01

    Nearly half of all H-alpha macrospicules in polar coronal holes appear to be miniature filament eruptions. This suggests that there is a large class of X-ray jets in which the jet-base magnetic arcade undergoes a blowout eruption as in a CME, instead of remaining static as in most solar X-ray jets, the standard jets that fit the model advocated by Shibata. Along with a cartoon depicting the standard model, we present a cartoon depicting the signatures expected of blowout jets in coronal X-ray images. From Hinode/XRT movies and STEREO/EUVI snapshots in polar coronal holes, we present examples of (1) X-ray jets that fit the standard model, and (2) X-ray jets that do not fit the standard model but do have features appropriate for blowout jets. These features are (1) a flare arcade inside the jet-base arcade in addition to the small flare arcade (bright point) outside that standard jets have, (2) a filament of cool (T is approximately 80,000K) plasma that erupts from the core of the jetbase arcade, and (3) an extra jet strand that should not be made by the reconnection for standard jets but could be made by reconnection between the ambient unipolar open field and the opposite-polarity leg of the filament-carrying flux-rope core field of the erupting jet-base arcade. We therefore infer that these non-standard jets are blowout jets, jets made by miniature versions of the sheared-core-arcade eruptions that make CMEs

  1. Tracking the Hercules 265 marine gas well blowout in the Gulf of Mexico

    Science.gov (United States)

    Romero, Isabel C.; Özgökmen, Tamay; Snyder, Susan; Schwing, Patrick; O'Malley, Bryan J.; Beron-Vera, Francisco J.; Olascoaga, Maria J.; Zhu, Ping; Ryan, Edward; Chen, Shuyi S.; Wetzel, Dana L.; Hollander, David; Murawski, Steven A.

    2016-01-01

    On 23 July 2013, a marine gas rig (Hercules 265) ignited in the northern Gulf of Mexico. The rig burned out of control for 2 days before being extinguished. We conducted a rapid-response sampling campaign near Hercules 265 after the fire to ascertain if sediments and fishes were polluted above earlier baseline levels. A surface drifter study confirmed that surface ocean water flowed to the southeast of the Hercules site, while the atmospheric plume generated by the blowout was in eastward direction. Sediment cores were collected to the SE of the rig at a distance of ˜0.2, 8, and 18 km using a multicorer, and demersal fishes were collected from ˜0.2 to 8 km SE of the rig using a longline (508 hooks). Recently deposited sediments document that only high molecular weight (HMW) polycyclic aromatic hydrocarbon (PAH) concentrations decreased with increasing distance from the rig suggesting higher pyrogenic inputs associated with the blowout. A similar trend was observed in the foraminifera Haynesina germanica, an indicator species of pollution. In red snapper bile, only HMW PAH metabolites increased in 2013 nearly double those from 2012. Both surface sediments and fish bile analyses suggest that, in the aftermath of the blowout, increased concentration of pyrogenically derived hydrocarbons was transported and deposited in the environment. This study further emphasizes the need for an ocean observing system and coordinated rapid-response efforts from an array of scientific disciplines to effectively assess environmental impacts resulting from accidental releases of oil contaminants.

  2. Stability and Blowout Behavior of Jet Flames in Oblique Air Flows

    Directory of Open Access Journals (Sweden)

    Jonathan N. Gomes

    2012-01-01

    Full Text Available The stability limits of a jet flame can play an important role in the design of burners and combustors. This study details an experiment conducted to determine the liftoff and blowout velocities of oblique-angle methane jet flames under various air coflow velocities. A nozzle was mounted on a telescoping boom to allow for an adjustable burner angle relative to a vertical coflow. Twenty-four flow configurations were established using six burner nozzle angles and four coflow velocities. Measurements of the fuel supply velocity during liftoff and blowout were compared against two parameters: nozzle angle and coflow velocity. The resulting correlations indicated that flames at more oblique angles have a greater upper stability limit and were more resistant to changes in coflow velocity. This behavior occurs due to a lower effective coflow velocity at angles more oblique to the coflow direction. Additionally, stability limits were determined for flames in crossflow and mild counterflow configurations, and a relationship between the liftoff and blowout velocities was observed. For flames in crossflow and counterflow, the stability limits are higher. Further studies may include more angle and coflow combinations, as well as the effect of diluents or different fuel types.

  3. 风蚀坑形态-动力学研究进展%A Review on Morphodynamic Processes of Blowouts

    Institute of Scientific and Technical Information of China (English)

    孙禹; 杜会石; 刘美萍; 哈斯

    2015-01-01

    Blowouts are depressions produced by wind erosion, which occur on sandy coasts or lake shores and sandy grasslands in arid and semi-arid rergions. Topographic steering changes the velocity and direction of air-flow within the blowout. Then a local difference in sediment transport exists, which changes the pattern of ero-sion and accumulation and reforms the morphology of the blowout. Topographic changing reacts on the near-surface airflow and forms the feedback and response mechanism between morphology and dynamics. This article briefly reviews the processes of morphodynamic and evolvement of blowouts, and analyzes its study trends, hoping to provide some reference for similar researches in the future. Although lots of progresses have been made in study of dynamic and evolvement of blowout, there are still many aspects need to be im-proved. First of all, airflow patterns in blowout are complicated, because of the limited field data, we often get an unreal construction and a poor understanding of airflow patterns. In order to aquire more sufficient field da-ta and precise analysis, more intense observation sites and continuous observations are needed. Secondly, tem-poral and spatial scales of previous researches in blowout are relatively small. Most of the research just fo-cused on the dynamics and evolvement of individual blowout, but ignored the others’in the same region;and limited observations to the current developmental situation, but ignored the processes or morphology in the past and future. In order to summarize a relatively complete evolutionary pattern of blowouts tentatively, the large-scale and long-term monitorings to the blowouts, which in variety of developmental phases are requisite. At last, compared with foreign researches which made certain achievements in coastal blowouts, domestic re-searches in evolutionary processes of inland blowouts which developed in different conditions and different genesises are deficient. Many blowouts which in

  4. From Blowout to Stalemate——China's Housing Market in 2007

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ As 2007 comes to an end, China's housing market is preparing for another controversial year.Increasingly restrictive macro-control policies and growing public concern have pushed China's housing market through the initial rise in price over the last couple years, a price blowout at the middle of this year, and finally the current stalemate between sellers and buyers. The end of 2007 has witnessed falling house prices in major cities,like Beijing, Shanghai, Guangzhou and Shenzhen. It seems that the inflexion of housing prices is right in front of us.Now, let's review some big events from 2007's housing market.

  5. Blowout jets and impulsive eruptive flares in a bald-patch topology

    Science.gov (United States)

    Chandra, R.; Mandrini, C. H.; Schmieder, B.; Joshi, B.; Cristiani, G. D.; Cremades, H.; Pariat, E.; Nuevo, F. A.; Srivastava, A. K.; Uddin, W.

    2017-01-01

    Context. A subclass of broad extreme ultraviolet (EUV) and X-ray jets, called blowout jets, have become a topic of research since they could be the link between standard collimated jets and coronal mass ejections (CMEs). Aims: Our aim is to understand the origin of a series of broad jets, some of which are accompanied by flares and associated with narrow and jet-like CMEs. Methods: We analyze observations of a series of recurrent broad jets observed in AR 10484 on 21-24 October 2003. In particular, one of them occurred simultaneously with an M2.4 flare on 23 October at 02:41 UT (SOLA2003-10-23). Both events were observed by the ARIES Hα Solar Tower-Telescope, TRACE, SOHO, and RHESSI instruments. The flare was very impulsive and followed by a narrow CME. A local force-free model of AR 10484 is the basis to compute its topology. We find bald patches (BPs) at the flare site. This BP topology is present for at least two days before to events. Large-scale field lines, associated with the BPs, represent open loops. This is confirmed by a global potential free source surface (PFSS) model. Following the brightest leading edge of the Hα and EUV jet emission, we can temporarily associate these emissions with a narrow CME. Results: Considering their characteristics, the observed broad jets appear to be of the blowout class. As the most plausible scenario, we propose that magnetic reconnection could occur at the BP separatrices forced by the destabilization of a continuously reformed flux rope underlying them. The reconnection process could bring the cool flux-rope material into the reconnected open field lines driving the series of recurrent blowout jets and accompanying CMEs. Conclusions: Based on a model of the coronal field, we compute the AR 10484 topology at the location where flaring and blowout jets occurred from 21 to 24 October 2003. This topology can consistently explain the origin of these events. The movie associated to Fig. 1 is available at http://www.aanda.org

  6. Surgical Treatment of Orbital Blowout Fractures: Complications and Postoperative Care Patterns.

    Science.gov (United States)

    Shew, Matthew; Carlisle, Michael P; Lu, Guanning Nina; Humphrey, Clinton; Kriet, J David

    2016-11-01

    Orbital fractures are a common result of facial trauma. Sequelae and indications for repair include enophthalmos and/or diplopia from extraocular muscle entrapment. Alloplastic implant placement with careful release of periorbital fat and extraocular muscles can effectively restore extraocular movements, orbital integrity, and anatomic volume. However, rare but devastating complications such as retrobulbar hematoma (RBH) can occur after repair, which pose a risk of permanent vision loss if not addressed emergently. For this reason, some surgeons take the precaution of admitting patients for 24-hour postoperative vision checks, while others do not. The incidence of postoperative RBH has not been previously reported and existing data are limited to case reports. Our aim was to examine national trends in postoperative management and to report the incidence of immediate postoperative complications at our institution following orbital repair. A retrospective assessment of orbital blowout fractures was undertaken to assess immediate postoperative complications including RBH. Only patients treated by a senior surgeon in the Department of Otolaryngology were included in the review. In addition, we surveyed AO North America (AONA) Craniomaxillofacial faculty to assess current trends in postoperative management. There were 80 patients treated surgically for orbital blowout fractures over a 9.5-year period. Nearly all patients were observed overnight (74%) or longer (25%) due to other trauma. Average length of stay was 17 hours for those observed overnight. There was one (1.3%) patient with RBH, who was treated and recovered without sequelae. Results of the survey indicated that a majority (64%) of responders observe postoperative patients overnight. Twenty-nine percent of responders indicated that they send patients home the same day of surgery. Performance of more than 20 orbital repairs annually significantly increased the likelihood that faculty would manage patients on

  7. Lean blowout limits of a gas turbine combustor operated with aviation fuel and methane

    Science.gov (United States)

    Xiao, Wei; Huang, Yong

    2016-05-01

    Lean blowout (LBO) limits is critical to the operational performance of combustion systems in propulsion and power generation. The swirl cup plays an important role in flame stability and has been widely used in aviation engines. Therefore, the effects of swirl cup geometry and flow dynamics on LBO limits are significant. An experiment was conducted for studying the lean blowout limits of a single dome rectangular model combustor with swirl cups. Three types of swirl cup (dual-axial swirl cup, axial-radial swirl cup, dual-radial swirl cup) were employed in the experiment which was operated with aviation fuel (Jet A-1) and methane under the idle condition. Experimental results showed that, with using both Jet A-1 and methane, the LBO limits increase with the air flow of primary swirler for dual-radial swirl cup, while LBO limits decrease with the air flow of primary swirler for dual-axial swirl cup. In addition, LBO limits increase with the swirl intensity for three swirl cups. The experimental results also showed that the flow dynamics instead of atomization poses a significant influence on LBO limits. An improved semi-empirical correlation of experimental data was derived to predict the LBO limits for gas turbine combustors.

  8. The persistence of large-scale blowouts in largely vegetated coastal dune fields

    Science.gov (United States)

    Delgado-Fernandez, Irene; Smyth, Thomas; Jackson, Derek; Davidson-Arnott, Robin; Smith, Alexander

    2016-04-01

    Coastal dunes move through natural phases of stability and instability during their evolution, displaying various temporal and spatial patterns across the dune field. Recent observations, however, have shown exceptionally rapid rates of stability through increased vegetative growth. This progressive vegetation colonisation and consequent loss of bare sand on coastal dune systems has been noted worldwide. Percentage reductions in bare sand of as much as 80% within just a few decades can been seen in examples from South Africa, Canada and Brazil as well as coastal dune sites across NW Europe. Despite these dramatic trends towards dune stabilisation, it is not uncommon to find particular examples of large-scale active blowouts and parabolic dunes within largely vegetated coastal dunes. While turbulence and airflow dynamics within features such as blowouts and other dune forms has been studied in detail within recent years, there is a lack of knowledge about what maintains dune mobility at these specific points in otherwise largely stabilized dune fields. This work explores the particular example of the 'Devil's Hole' blowout, Sefton Dunes, NW England. Approximately 300 m long by 100 m wide, its basin is below the water-table which leads to frequent flooding. Sefton Dunes in general have seen a dramatic loss of bare sand since the 1940s. However, and coinciding with this period of dune stabilisation, the 'Devil's Hole' has not only remained active but also grown in size at a rate of 4.5 m year-1 along its main axis. An exploration of factors controlling the maintenance of open bare sand areas at this particular location is examined using a variety of techniques including Computational Fluid Dynamics (CFD) airflow modelling and in situ empirical measurements of (short-term experiments) of wind turbulence and sand transport. Field measurements of wind parameters and transport processes were collected over a 2 week period during October 2015. Twenty three 3D ultrasonic

  9. Effects of Various Blowout Panel Configurations on the Structural Response of LANL Building 16-340 to Internal Explosions

    Energy Technology Data Exchange (ETDEWEB)

    Wilke, Jason P. [New Mexico Inst. of Mining and Technology, Socorro, NM (United States)

    2005-09-01

    The risk of accidental detonation is present whenever any type of high explosives processing activity is performed. These activities are typically carried out indoors to protect processing equipment from the weather and to hide possibly secret processes from view. Often, highly strengthened reinforced concrete buildings are employed to house these activities. These buildings may incorporate several design features, including the use of lightweight frangible blowout panels, to help mitigate blast effects. These panels are used to construct walls that are durable enough to withstand the weather, but are of minimal weight to provide overpressure relief by quickly moving outwards and creating a vent area during an accidental explosion. In this study the behavior of blowout panels under various blast loading conditions was examined. External loadings from explosions occurring in nearby rooms were of primary interest. Several reinforcement systems were designed to help blowout panels resist failure from external blast loads while still allowing them to function as vents when subjected to internal explosions. The reinforcements were studied using two analytical techniques, yield-line analysis and modal analysis, and the hydrocode AUTODYN. A blowout panel reinforcement design was created that could prevent panels from being blown inward by external explosions. This design was found to increase the internal loading of the building by 20%, as compared with nonreinforced panels. Nonreinforced panels were found to increase the structural loads by 80% when compared to an open wall at the panel location.

  10. Blow-out limits of nonpremixed turbulent jet flames in a cross flow at atmospheric and sub-atmospheric pressures

    KAUST Repository

    Wang, Qiang

    2015-07-22

    The blow-out limits of nonpremixed turbulent jet flames in cross flows were studied, especially concerning the effect of ambient pressure, by conducting experiments at atmospheric and sub-atmospheric pressures. The combined effects of air flow and pressure were investigated by a series of experiments conducted in an especially built wind tunnel in Lhasa, a city on the Tibetan plateau where the altitude is 3650 m and the atmospheric pressure condition is naturally low (64 kPa). These results were compared with results obtained from a wind tunnel at standard atmospheric pressure (100 kPa) in Hefei city (altitude 50 m). The size of the fuel nozzles used in the experiments ranged from 3 to 8 mm in diameter and propane was used as the fuel. It was found that the blow-out limit of the air speed of the cross flow first increased (“cross flow dominant” regime) and then decreased (“fuel jet dominant” regime) as the fuel jet velocity increased in both pressures; however, the blow-out limit of the air speed of the cross flow was much lower at sub-atmospheric pressure than that at standard atmospheric pressure whereas the domain of the blow-out limit curve (in a plot of the air speed of the cross flow versus the fuel jet velocity) shrank as the pressure decreased. A theoretical model was developed to characterize the blow-out limit of nonpremixed jet flames in a cross flow based on a Damköhler number, defined as the ratio between the mixing time and the characteristic reaction time. A satisfactory correlation was obtained at relative strong cross flow conditions (“cross flow dominant” regime) that included the effects of the air speed of the cross flow, fuel jet velocity, nozzle diameter and pressure.

  11. Large-Scale Elongated Gas Blowouts, Offshore Virginia/North Carolina: Process and Product

    Science.gov (United States)

    Hill, J. C.; Driscoll, N. W.; Weissel, J. K.; Goff, J. A.

    2002-12-01

    A shipboard program conducted in May 2000 onboard the R/V Hatteras provided major new insight into the origin of the enigmatic "crack"-like features arranged in en-echelon fashion along a 40 km-long stretch of the outermost shelf off Virginia and North Carolina. High-resolution side-scan backscatter and chirp subbottom reflection data show the features are not simple normal faults, but appear to be large-scale excavations or craters resulting from massive expulsion of gas through the seafloor. Visualization of the dip- and strike-line sonar mosaics in three dimensions, along with co-registered seismic data, has improved the spatial resolution of the features and reveals a strong correlation between trapped gas and internally deformed, deltaic strata that drape the shelf edge. The geometry of the blowouts and their location along the outer shelf suggests a composite formation of the pockmark features, combining gas accumulation, down-slope creep of the deltaic strata and fluid expulsion. Shallow gas accumulation is seen clearly in the chirp profiles as bright, high amplitude reflections, obscuring any deeper reflectors. The gas is trapped beneath a thin veneer (few tens of meters) of stratified sediment draped across the outermost shelf/upper slope, which is interpreted as a shelf-edge delta, probably deposited since the last glacial maximum (LGM). The chirp data show clear evidence of internal deformation of the shelf-edge delta, including thickening and thinning of chaotic or transparent layers, segmentation and rotation of superjacent sections, and homoclinal contacts that emphasize contrasts between transparent and reflective intervals. The observed stratigraphic disturbance, most likely a result of downslope creep processes, is interpreted to create permeable pathways for upslope/updip gas migration and eventual expulsion. In summary, the new data 1) show that gas expulsion occurred after the deposition of a seaward-dipping wedge of sediments, which we suggest

  12. Formation dynamics of subsurface hydrocarbon intrusions following the Deepwater Horizon blowout

    Science.gov (United States)

    Socolofsky, Scott A.; Adams, E. Eric; Sherwood, Christopher R.

    2011-01-01

    Hydrocarbons released following the Deepwater Horizon (DH) blowout were found in deep, subsurface horizontal intrusions, yet there has been little discussion about how these intrusions formed. We have combined measured (or estimated) observations from the DH release with empirical relationships developed from previous lab experiments to identify the mechanisms responsible for intrusion formation and to characterize the DH plume. Results indicate that the intrusions originate from a stratification-dominated multiphase plume characterized by multiple subsurface intrusions containing dissolved gas and oil along with small droplets of liquid oil. Unlike earlier lab measurements, where the potential density in ambient water decreased linearly with elevation, at the DH site it varied quadratically. We have modified our method for estimating intrusion elevation under these conditions and the resulting estimates agree with observations that the majority of the hydrocarbons were found between 800 and 1200 m.

  13. Computationally efficient methods for modelling laser wakefield acceleration in the blowout regime

    CERN Document Server

    Cowan, B M; Beck, A; Davoine, X; Bunkers, K; Lifschitz, A F; Lefebvre, E; Bruhwiler, D L; Shadwick, B A; Umstadter, D P

    2012-01-01

    Electron self-injection and acceleration until dephasing in the blowout regime is studied for a set of initial conditions typical of recent experiments with 100 terawatt-class lasers. Two different approaches to computationally efficient, fully explicit, three-dimensional particle-in-cell modelling are examined. First, the Cartesian code VORPAL using a perfect-dispersion electromagnetic solver precisely describes the laser pulse and bubble dynamics, taking advantage of coarser resolution in the propagation direction, with a proportionally larger time step. Using third-order splines for macroparticles helps suppress the sampling noise while keeping the usage of computational resources modest. The second way to reduce the simulation load is using reduced-geometry codes. In our case, the quasi-cylindrical code CALDER-CIRC uses decomposition of fields and currents into a set of poloidal modes, while the macroparticles move in the Cartesian 3D space. Cylindrical symmetry of the interaction allows using just two mo...

  14. Guidelines for estimating blowout rates and duration for environmental risk analysis purposes; Retningslinjer for beregning av utblaasningsrater og -varighet til bruk ved analyse av miljoerisiko

    Energy Technology Data Exchange (ETDEWEB)

    Nilsen, Thomas

    2007-01-15

    Risk assessment in relation to possible blowouts of oil and condensate is the main topic in this analysis. The estimated risk is evaluated against criteria for acceptable risk and is part of the foundation for dimensioning in oil spill preparedness. The report aims to contribute to the standardisation of the terminology, methodology and documentation for estimations of blowout rates, and thus to simplify communication of the analysis results and strengthen the decision makers' trust in these (ml)

  15. Computer simulation of reservoir depletion and oil flow from the Macondo well following the Deepwater Horizon blowout

    Science.gov (United States)

    Hsieh, Paul

    2010-01-01

    This report describes the application of a computer model to simulate reservoir depletion and oil flow from the Macondo well following the Deepwater Horizon blowout. Reservoir and fluid data used for model development are based on (1) information released in BP's investigation report of the incident, (2) information provided by BP personnel during meetings in Houston, Texas, and (3) calibration by history matching to shut-in pressures measured in the capping stack during the Well Integrity Test. The model is able to closely match the measured shut-in pressures. In the simulation of the 86-day period from the blowout to shut in, the simulated reservoir pressure at the well face declines from the initial reservoir pressure of 11,850 pounds per square inch (psi) to 9,400 psi. After shut in, the simulated reservoir pressure recovers to a final value of 10,300 psi. The pressure does not recover back to the initial pressure owing to reservoir depletion caused by 86 days of oil discharge. The simulated oil flow rate declines from 63,600 stock tank barrels per day just after the Deepwater Horizon blowout to 52,600 stock tank barrels per day just prior to shut in. The simulated total volume of oil discharged is 4.92 million stock tank barrels. The overall uncertainty in the simulated flow rates and total volume of oil discharged is estimated to be + or - 10 percent.

  16. Minifilament Eruption as the Source of a Blowout Jet, C-class Flare, and Type-III Radio Burst

    Science.gov (United States)

    Hong, Junchao; Jiang, Yunchun; Yang, Jiayan; Li, Haidong; Xu, Zhe

    2017-01-01

    We report a strong minifilament eruption associated with Geostationary Operational Environmental Satellite C1.6 flare and WIND type-III radio burst. The minifilament, which lies at the periphery of active region 12259, is detected by Hα images from the New Vacuum Solar Telescope. The minifilament undergoes a partial and then a full eruption. Simultaneously, two co-spatial jets are successively observed in extreme ultraviolet images from the Solar Dynamic Observatory. The first jet exhibits a typical fan-spine geometry, suggesting that the co-spatial minifilament is possibly embedded in magnetic fields with a fan-spine structure. However, the second jet displays blowout morphology when the entire minifilament erupts upward, leaving behind a hard X-ray emission source in the base. Differential emission measure analyses show that the eruptive region is heated up to about 4 MK during the fan-spine jet, while up to about 7 MK during the blowout jet. In particular, the blowout jet is accompanied by an interplanetary type-III radio burst observed by WIND/WAVES in the frequency range from above 10 to 0.1 MHz. Hence, the minifilament eruption is correlated with the interplanetary type-III radio burst for the first time. These results not only suggest that coronal jets can result from magnetic reconnection initiated by erupting minifilaments with open fields, but also shed light on the potential influence of minifilament eruption on interplanetary space.

  17. Self-Sealing Shells: Blowouts and Blisters on the Surfaces of Leaky Wind-Blown-Bubbles and Supernova Remnants

    CERN Document Server

    Pittard, Julian

    2013-01-01

    Blowouts can occur when a dense shell confining hot, high pressure, gas ruptures. The venting gas inflates a blister on the surface of the shell. Here we examine the growth of such blisters on the surfaces of wind-blown-bubbles (WBBs) and supernova remnants (SNRs) due to shell rupture caused by the Vishniac instability. On WBBs the maximum relative size of the blister (R_bstall/R) is found to grow linearly with time, but in many cases the blister radius will not exceed 20 per cent of the bubble radius. Thus blowouts initiated by the Vishniac instability are unlikely to have a major effect on the global dynamics and properties of the bubble. The relative size of blisters on SNRs is even smaller than on WBBs, with blisters only growing to a radius comparable to the thickness of the cold shell of SNRs. The small size of the SNR blowouts is, however, in good agreement with observations of blisters in the Vela SNR. The difference in relative size between WBB and SNR blisters is due to the much higher speed at whic...

  18. Flame blowout and pollutant emissions in vitiated combustion of conventional and bio-derived fuels

    Science.gov (United States)

    Singh, Bhupinder

    The widening gap between the demand and supply of fossil fuels has catalyzed the exploration of alternative sources of energy. Interest in the power, water extraction and refrigeration (PoWER) cycle, proposed by the University of Florida, as well as the desirability of using biofuels in distributed generation systems, has motivated the exploration of biofuel vitiated combustion. The PoWER cycle is a novel engine cycle concept that utilizes vitiation of the air stream with externally-cooled recirculated exhaust gases at an intermediate pressure in a semi-closed cycle (SCC) loop, lowering the overall temperature of combustion. It has several advantages including fuel flexibility, reduced air flow, lower flame temperature, compactness, high efficiency at full and part load, and low emissions. Since the core engine air stream is vitiated with the externally cooled exhaust gas recirculation (EGR) stream, there is an inherent reduction in the combustion stability for a PoWER engine. The effect of EGR flow and temperature on combustion blowout stability and emissions during vitiated biofuel combustion has been characterized. The vitiated combustion performance of biofuels methyl butanoate, dimethyl ether, and ethanol have been compared with n-heptane, and varying compositions of syngas with methane fuel. In addition, at high levels of EGR a sharp reduction in the flame luminosity has been observed in our experimental tests, indicating the onset of flameless combustion. This drop in luminosity may be a result of inhibition of processes leading to the formation of radiative soot particles. One of the objectives of this study is finding the effect of EGR on soot formation, with the ultimate objective of being able to predict the boundaries of flameless combustion. Detailed chemical kinetic simulations were performed using a constant-pressure continuously stirred tank reactor (CSTR) network model developed using the Cantera combustion code, implemented in C++. Results have

  19. Availability analysis of subsea blowout preventer using Markov model considering demand rate

    Science.gov (United States)

    Kim, Sunghee; Chung, Soyeon; Yang, Youngsoon

    2014-12-01

    Availabilities of subsea Blowout Preventers (BOP) in the Gulf of Mexico Outer Continental Shelf (GoM OCS) is investigated using a Markov method. An updated β factor model by SINTEF is used for common-cause failures in multiple redundant systems. Coefficient values of failure rates for the Markov model are derived using the β factor model of the PDS (reliability of computer-based safety systems, Norwegian acronym) method. The blind shear ram preventer system of the subsea BOP components considers a demand rate to reflect reality more. Markov models considering the demand rate for one or two components are introduced. Two data sets are compared at the GoM OCS. The results show that three or four pipe ram preventers give similar availabilities, but redundant blind shear ram preventers or annular preventers enhance the availability of the subsea BOP. Also control systems (PODs) and connectors are contributable components to improve the availability of the subsea BOPs based on sensitivity analysis.

  20. Trace element distributions in the water column near the Deepwater Horizon well blowout.

    Science.gov (United States)

    Joung, DongJoo; Shiller, Alan M

    2013-03-05

    To understand the impact of the Deepwater Horizon well blowout on dissolved trace element concentrations, samples were collected from areas around the oil rig explosion site during four cruises in early and late May 2010, October 2010, and October 2011. In surface waters, Ba, Fe, Cu, Ni, Mn, and Co were relatively well correlated with salinity during all cruises, suggesting mixing with river water was the main influence on metal distributions in these waters. However, in deep oil/gas plumes (1000-1400 m depth), modestly elevated concentrations of Co and Ba were observed in late May, compared with postblowout conditions. Analysis of the oil itself along with leaching experiments confirm the oil as the source of the Co, whereas increased Ba was likely due to drilling mud used in the top kill attempt. Deep plume dissolved Mn largely reflected natural benthic input, though some samples showed slight elevation probably associated with the top kill. Dissolved Fe concentrations were low and also appeared largely topographically controlled and reflective of benthic input. Estimates suggest that microbial Fe demand may have affected the Fe distribution but probably not to the extent of Fe becoming a growth-limiting factor. Experiments showed that the dispersant can have some limited impact on dissolved-particulate metal partitioning.

  1. Application of Bayesian networks in quantitative risk assessment of subsea blowout preventer operations.

    Science.gov (United States)

    Cai, Baoping; Liu, Yonghong; Liu, Zengkai; Tian, Xiaojie; Zhang, Yanzhen; Ji, Renjie

    2013-07-01

    This article proposes a methodology for the application of Bayesian networks in conducting quantitative risk assessment of operations in offshore oil and gas industry. The method involves translating a flow chart of operations into the Bayesian network directly. The proposed methodology consists of five steps. First, the flow chart is translated into a Bayesian network. Second, the influencing factors of the network nodes are classified. Third, the Bayesian network for each factor is established. Fourth, the entire Bayesian network model is established. Lastly, the Bayesian network model is analyzed. Subsequently, five categories of influencing factors, namely, human, hardware, software, mechanical, and hydraulic, are modeled and then added to the main Bayesian network. The methodology is demonstrated through the evaluation of a case study that shows the probability of failure on demand in closing subsea ram blowout preventer operations. The results show that mechanical and hydraulic factors have the most important effects on operation safety. Software and hardware factors have almost no influence, whereas human factors are in between. The results of the sensitivity analysis agree with the findings of the quantitative analysis. The three-axiom-based analysis partially validates the correctness and rationality of the proposed Bayesian network model.

  2. Blowout win : advances in BOP technology cut waste and make work safer for drilling crews

    Energy Technology Data Exchange (ETDEWEB)

    Budd, G.

    2008-03-15

    With the advent of programmable logic controllers (PLCs), there has been significant improvement in the way that blowout prevention (BOP) equipment can be controlled and operated. The accumulator, which provides the energy to operate the BOP, usually includes compressed gas bottles, regulator valves, pumps, a hydraulic reservoir, a manifold, and control valves. PLCs have made the accumulator easier to operate since they have eliminated much of the cable that spans from the control panel to the rig control shack. The control unit currently consists of some computer chips and a printed circuit instead of miles of wires and cables. In addition to providing efficient BOP control, PLCs have enabled rig managers to readily identify and fix problems. Some manufacturers have included remote troubleshooting capability for the accumulator. Advances in BOP technology and controls have been driven by the challenges of drilling in harsh offshore environments. However, some operators in the Western Canadian Sedimentary Basin continue to use BOP systems that have been around for decades because of their reputation for reliability and low-maintenance requirements. 1 fig.

  3. Blowout Jets and Impulsive Eruptive Flare in a Bald-Patch Topology

    CERN Document Server

    Chandra, R; Schmieder, B; Joshi, B; Cristiani, G D; Cremades, H; Pariat, E; Nuevo, F A; Srivastava, A K; Uddin, W

    2016-01-01

    Context: A subclass of broad EUV and X-ray jets, called blowout jets, have become a topic of research since they could be the link between standard collimated jets and CMEs.} Aim: Our aim is to understand the origin of a series of broad jets, some accompanied by flares and associated with narrow and jet-like CMEs. Methods: We analyze observations of a series of recurrent broad jets observed in AR 10484 on 21-24 October 2003. In particular, one of them occurred simultaneously with an M2.4 flare on 23 October at 02:41 UT (SOLA2003-10-23). Both events were observed by ARIES H-alpha Solar Tower-Telescope, TRACE, SOHO, and RHESSI instruments. The flare was very impulsive and followed by a narrow CME. A local force-free model of AR 10484 is the basis to compute its topology. We find bald patches (BPs) at the flare site. This BP topology is present for at least two days before. Large-scale field lines, associated with the BPs, represent open loops. This is confirmed by a global PFSS model. Following the brightest le...

  4. Pure orbital blowout fractures reconstructed with autogenous bone grafts: functional and aesthetic outcomes.

    Science.gov (United States)

    Kronig, S A J; van der Mooren, R J G; Strabbing, E M; Stam, L H M; Tan, J A S L; de Jongh, E; van der Wal, K G H; Paridaens, D; Koudstaal, M J

    2016-04-01

    The purpose of this study was to investigate the ophthalmic clinical findings following surgical reconstruction with autogenous bone grafts of pure blowout fractures. A retrospective review of 211 patients who underwent surgical repair of an orbital fracture between October 1996 and December 2013 was performed. Following data analysis, 60 patients who were followed up over a period of 1 year were included. A solitary floor fracture was present in 38 patients and a floor and a medial wall fracture in 22 patients. Comparing preoperative findings between these two groups, preoperative diplopia and enophthalmos were almost twice as frequent in the group with additional medial wall fractures: diplopia 8% and 14% and enophthalmos 18% and 55%, respectively. One year following surgery there was no diplopia present in either group. In the solitary floor fracture group, 3% still had enophthalmos. It can be concluded that at 1 year following the repair of pure orbital floor fractures using autogenous bone, good functional and aesthetic results can be obtained. In the group with both floor and medial wall fractures, no enophthalmos was found when both walls were reconstructed. When the medial wall was left unoperated, 29% of patients still suffered from enophthalmos after 1 year.

  5. Availability analysis of subsea blowout preventer using Markov model considering demand rate

    Directory of Open Access Journals (Sweden)

    Kim Sunghee

    2014-12-01

    Full Text Available Availabilities of subsea Blowout Preventers (BOP in the Gulf of Mexico Outer Continental Shelf (GoM OCS is investigated using a Markov method. An updated β factor model by SINTEF is used for common-cause failures in multiple redundant systems. Coefficient values of failure rates for the Markov model are derived using the β factor model of the PDS (reliability of computer-based safety systems, Norwegian acronym method. The blind shear ram preventer system of the subsea BOP components considers a demand rate to reflect reality more. Markov models considering the demand rate for one or two components are introduced. Two data sets are compared at the GoM OCS. The results show that three or four pipe ram preventers give similar availabilities, but redundant blind shear ram preventers or annular preventers enhance the availability of the subsea BOP. Also control systems (PODs and connectors are contributable components to improve the availability of the subsea BOPs based on sensitivity analysis.

  6. Endovascular treatment paradigm of carotid blowout syndrome: Review of 8-years experience

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Wing Suet, E-mail: wws351@ha.org.hk [Department of Radiology, Tuen Mun Hospital, Tuen Mun (Hong Kong); Lai, Vincent, E-mail: vincentlai@hkcr.org [Department of Radiology, Tuen Mun Hospital, Tuen Mun (Hong Kong); Lau, Hin Yue, E-mail: lhy460@ha.org.hk [Department of Radiology, Tuen Mun Hospital, Tuen Mun (Hong Kong); Wong, Yiu Chung, E-mail: wongyc6@ha.org.hk [Department of Radiology, Tuen Mun Hospital, Tuen Mun (Hong Kong); Poon, Wai Lun, E-mail: poonwl@ha.org.hk [Department of Radiology, Tuen Mun Hospital, Tuen Mun (Hong Kong); Tan, Chong Boon, E-mail: tancb@ha.org.hk [Department of Radiology, Tuen Mun Hospital, Tuen Mun (Hong Kong)

    2013-01-15

    Objectives: Endovascular treatment is effective in treating carotid blowout syndrome (CBS). We reviewed our experience in addressing CBS over eight years and presented an account of the treatment paradigm and management algorithm. Method: All cases of CBS from 2003 to 2010 with endovascular treatment performed in our center were reviewed. 15 CBS in 14 patients were recruited. Based on our management algorithm, treatment regimen was stratified into deconstructive or constructive methods. Their clinical presentations, angiographic features, angiographic and clinical outcomes were reviewed. Results: 10 patients were treated with deconstructive method by means of permanent vessel occlusion (PVO) and 4 patients were treated with constructive method by means of placement of covered stent (n = 3) or flow diverting device (n = 1). Immediate hemostasis was achieved in all cases. 7 (50%) patients, in whom 5 treated with PVO and 2 with covered stent, had favorable outcomes and survived at a median follow-up period of 4 months (range: 1–84 months). Conclusion: Permanent vessel occlusion remains the gold standard of treatment and tends to show a favorable long-term outcome. Off-label use of covered stent and flow-diverting device can produce satisfactory results should balloon occlusion test fail, but long-term follow up would be required for definitive assessment.

  7. Periodic orbit analysis at the onset of the unstable dimension variability and at the blowout bifurcation.

    Science.gov (United States)

    Pereira, R F; de S Pinto, S E; Viana, R L; Lopes, S R; Grebogi, C

    2007-06-01

    Many chaotic dynamical systems of physical interest present a strong form of nonhyperbolicity called unstable dimension variability (UDV), for which the chaotic invariant set contains periodic orbits possessing different numbers of unstable eigendirections. The onset of UDV is usually related to the loss of transversal stability of an unstable fixed point embedded in the chaotic set. In this paper, we present a new mechanism for the onset of UDV, whereby the period of the unstable orbits losing transversal stability tends to infinity as we approach the onset of UDV. This mechanism is unveiled by means of a periodic orbit analysis of the invariant chaotic attractor for two model dynamical systems with phase spaces of low dimensionality, and seems to depend heavily on the chaotic dynamics in the invariant set. We also described, for these systems, the blowout bifurcation (for which the chaotic set as a whole loses transversal stability) and its relation with the situation where the effects of UDV are the most intense. For the latter point, we found that chaotic trajectories off, but very close to, the invariant set exhibit the same scaling characteristic of the so-called on-off intermittency.

  8. SDO and Hinode observations of a blowout jet in a coronal hole

    CERN Document Server

    Young, Peter

    2013-01-01

    A blowout jet occurred within the south coronal hole on 2011 February 9 at 09:00 UT and was observed by the Atmospheric Imaging Assembly (AIA) and Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory, and the EUV Imaging Spectrometer (EIS) and X-Ray Telescope (XRT) on board the Hinode satellite during coronal hole monitoring performed as part of Hinode Operations Program No. 177. Images from AIA show expanding, hot and cold loops from a small bright point with plasma ejected in a curtain up to 30 Mm wide. The initial intensity front of the jet has a projected velocity of 200 km/s, and line-of-sight velocities measured by EIS are between 100 and 250 km/s. The jet plasma has a density of 2.7 x 10^8 cm^-3, and a temperature of 1.4 MK. During the event a number of bright kernels are seen at the base of the bright point. The kernels have sizes of 1000 km, are variable in brightness, and have lifetimes of 1-15 mins. A XRT filter ratio yields temperatures of 1.5-3.0 MK for the kernels. The ...

  9. Observations of quasi-periodic phenomena associated with a large blowout solar jet

    CERN Document Server

    Morton, R J; Erdélyi, R

    2012-01-01

    A variety of periodic phenomena have been observed in conjunction with large solar jets. We aim to find further evidence for {(quasi-)}periodic behaviour in solar jets and determine what the periodic behaviour can tell us about the excitation mechanism and formation process of the large solar jet. Using the 304 {\\AA} (He-II), 171 {\\AA} (Fe IX), 193 {\\AA} (Fe XII/XXIV) and 131 {\\AA} (Fe VIII/XXI) filters on-board the Solar Dynamic Observatory (SDO) Atmospheric Imaging Assembly (AIA), we investigate the intensity oscillations associated with a solar jet. Evidence is provided for multiple magnetic reconnection events occurring between a pre-twisted, closed field and open field lines. Components of the jet are seen in multiple SDO/AIA filters covering a wide range of temperatures, suggesting the jet can be classified as a blowout jet. Two bright, elongated features are observed to be co-spatial with the large jet, appearing at the jet's footpoints. Investigation of these features reveal they are defined by multip...

  10. Intrusion dynamics of particle plumes in stratified water with weak crossflow: Application to deep ocean blowouts

    Science.gov (United States)

    Wang, Dayang; Adams, E. Eric

    2016-06-01

    We present an experimental study of particle plumes in ambient stratification and a mild current. In an inverted framework, the results describe the fate of oil droplets released from a deep ocean blowout. A continuous stream of dense glass beads was released from a carriage towed in a salt-stratified tank. Nondimensional particle slip velocity UN ranged from 0.1 to 1.9, and particles with UN ≤ 0.5 were observed to enter the intrusion layer. The spatial distributions of beads, collected on a bottom sled towed with the source, present a Gaussian distribution in the transverse direction and a skewed distribution in the along-current direction. Dimensions of the distributions increase with decreasing UN. The spreading relations can be used as input to far-field models describing subsequent transport of particles or, in an inverted framework, oil droplets. The average particle settling velocity, Uave, was found to exceed the individual particle slip velocity, Us, which is attributed to the initial plume velocity near the point of release. Additionally, smaller particles exhibit a "group" or "secondary plume" effect as they exit the intrusion as a swarm. The secondary effect becomes more prominent as UN decreases, and might help explain observations from the 2000 Deep Spill field experiment where oil was found to surface more rapidly than predicted based on Us. An analytical model predicting the particle deposition patterns was validated against experimental measurements, and used to estimate near-field oil transport under the Deepwater Horizon spill conditions, with/without chemical dispersants.

  11. Bow-tie model for offshore drilling blowout accident%海上钻井井喷事故的蝴蝶结模型

    Institute of Scientific and Technical Information of China (English)

    薛鲁宁; 樊建春; 张来斌

    2013-01-01

    海上钻井是一个复杂的动态系统,同时又与一般的过程工业一样,可以划分为清晰的操作步骤和流程,因此安全屏障理论的过程模型非常适合分析海上钻井作业的安全.井喷是海上钻井作业的重要威胁,井喷事故模型对于指导海上钻井安全有重要意义.以安全屏障为基础,利用事故树和事件树分析方法,建立了海上钻井井喷事故的蝴蝶结模型.利用事故树方法分析了井喷事件的原因,通过事件树方法分析了井喷发生后火灾爆炸事故的发展过程.通过将事件原因及事故后果综合为一个模型,操作者可以很直观地了解井喷事故的发生发展过程,进而为其寻找相应的预防及控制措施提供指导.最后将“深水地平线”事故应用于该模型,验证了该模型分析海上钻井井喷事故的有效性.%Offshore drilling is a complex and dynamic system. Meanwhile, like any other process industry, it can also be divided into several independent operating steps and procedures. Therefore, the process model of safety barrier is very suitable to analyze safety of offshore drilling operations. Blowout was an important threat to offshore drilling. A blowout accident model is very meaningful to instruct offshore drilling safety. Based on safety barrier theory, a bow-tie model for offshore drilling blowout was established by utilizing fault tree and event tree methods. Causes of an offshore drilling blowout event were analyzed by fault tree, while development processes of fire & explosion accident after a blowout event were analyzed by event tree. Causes of an offshore drilling blowout event and consequences of fire & explosion accident after the blowout were combined into a single model. This model is very convenient for operators to understand the whole generating and developing process of an offshore drilling blowout accident. Therefore, it can be used as a guide for offshore drilling operators to find relevant

  12. Effects of Laser Pulse Heating of Copper Photocathodes on High-brightness Electron Beam Production at Blowout Regime

    CERN Document Server

    Zheng, Lianmin; Tang, Chuanxiang; Gai, Wei

    2016-01-01

    Producing high-brightness and high-charge (>100 pC) electron bunches at blowout regime requires ultrashort laser pulse with high fluence. The effects of laser pulse heating of the copper photocathode are analyzed in this paper. The electron and lattice temperature is calculated using an improved two-temperature model, and an extended Dowell-Schmerge model is employed to calculate the thermal emittance and quantum efficiency. A time-dependent growth of the thermal emittance and the quantum efficiency is observed. For a fixed amount of charge, the projected thermal emittance increases with the decreasing laser radius, and this effect should be taken into account in the laser optimization at blowout regime. Moreover, laser damage threshold fluence is simulated, showing that the maximum local fluence should be less than 40 mJ/cm^2 to prevent damage to the cathode. The cryogenic effect on the laser pulse heating is studied, showing that the hazards caused by the laser pulse heating will be significantly mitigated ...

  13. Multiscale plume modeling of the Deepwater Horizon oil-well blowout for environmental impact assessment and mitigation

    Science.gov (United States)

    Socolofsky, S. A.; Rezvani, M.

    2010-12-01

    The accidental blowout plume of the Deepwater Horizon (DH) oil well is an unprecedented event that will have far-reaching environmental, economic, and societal impact. The subsurface structure of the blowout plume, including its layered system of intrusions, conforms qualitatively to that predicted in the literature; however, new modeling tools are currently needed to produce highly-resolved predictions of such a complex plume in the stratified and flowing ocean. We present laboratory experiments of multiphase plumes in stratification and crossflow to understand the physical mechanisms that lead to separation among the buoyant dispersed phases (oil and gas) and the entrained and dissolved constituents in the continuous phase. Scale analysis indicates that the DH plume is stratification dominated, and observed locations of hydrocarbon intrusion layers agree well with the experimentally derived empirical scaling laws. New flow visualization measurements in gas plumes in stratification demonstrate that unsteady plume oscillation and detrainment events result from regular shedding of coherent structures on the order of the plume width and are not directly related to the stratification frequency. Similar particle image velocimetry (PIV) measurements in weak crossflows characterize the transport mechanisms in the plume wake. The results of these experiments will be used in the context of a National Science Foundation RAPID grant to validate a nested large eddy simulations (LES) / Reynolds averaged Navier-Stokes (RANS) model of the DH plume, and early results from this model demonstrate its feasibility to capture the unsteady and complex structure of the plume evolution.

  14. Well blowout rates and consequences in California Oil and Gas District 4 from 1991 to 2005: Implications for geological storage of carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, Preston; Jordan, Preston D.; Benson, Sally M.

    2008-05-15

    Well blowout rates in oil fields undergoing thermally enhanced recovery (via steam injection) in California Oil and Gas District 4 from 1991 to 2005 were on the order of 1 per 1,000 well construction operations, 1 per 10,000 active wells per year, and 1 per 100,000 shut-in/idle and plugged/abandoned wells per year. This allows some initial inferences about leakage of CO2 via wells, which is considered perhaps the greatest leakage risk for geological storage of CO2. During the study period, 9% of the oil produced in the United States was from District 4, and 59% of this production was via thermally enhanced recovery. There was only one possible blowout from an unknown or poorly located well, despite over a century of well drilling and production activities in the district. The blowout rate declined dramatically during the study period, most likely as a result of increasing experience, improved technology, and/or changes in safety culture. If so, this decline indicates the blowout rate in CO2-storage fields can be significantly minimized both initially and with increasing experience over time. Comparable studies should be conducted in other areas. These studies would be particularly valuable in regions with CO2-enhanced oil recovery (EOR) and natural gas storage.

  15. Effects of Various Blowout Panel Configurations on the Structural Response of Los Alamos National Laboratory Building 16-340 to Internal Explosions

    Energy Technology Data Exchange (ETDEWEB)

    Wilke, Jason P. [New Mexico Inst. of Mining and Technology, Socorro, NM (United States)

    2005-09-01

    The risk of accidental detonation is present whenever any type of high explosives processing activity is performed. These activities are typically carried out indoors to protect processing equipment from the weather and to hide possibly secret processes from view. Often, highly strengthened reinforced concrete buildings are employed to house these activities. These buildings may incorporate several design features, including the use of lightweight frangible blowout panels, to help mitigate blast effects. These panels are used to construct walls that are durable enough to withstand the weather, but are of minimal weight to provide overpressure relief by quickly moving outwards and creating a vent area during an accidental explosion. In this study the behavior of blowout panels under various blast loading conditions was examined. External loadings from explosions occurring in nearby rooms were of primary interest. Several reinforcement systems were designed to help blowout panels resist failure from external blast loads while still allowing them to function as vents when subjected to internal explosions. The reinforcements were studied using two analytical techniques, yield-line analysis and modal analysis, and the hydrocode AUTODYN. A blowout panel reinforcement design was created that could prevent panels from being blown inward by external explosions. This design was found to increase the internal loading of the building by 20%, as compared with nonreinforced panels. Nonreinforced panels were found to increase the structural loads by 80% when compared to an open wall at the panel location.

  16. Was the extreme and widespread marine oil-snow sedimentation and flocculent accumulation (MOSSFA) event during the Deepwater Horizon blow-out unique?

    NARCIS (Netherlands)

    Vonk, S.M.; Hollander, D.J.; Murk, A.J.

    2015-01-01

    During the Deepwater Horizon blowout, thick layers of oiled material were deposited on the deep seafloor. This large scale benthic concentration of oil is suggested to have occurred via the process of Marine Oil Snow Sedimentation and Flocculent Accumulation (MOSSFA). This meta-analysis investigates

  17. 基于系统动力学的井喷事故仿真研究%Study on Simulation of Blowout Accidents Based on System Dynamics

    Institute of Scientific and Technical Information of China (English)

    吉安民; 何沙

    2011-01-01

    In order to forecast the development process of blowout accident dynamically, a system simulation flow chart for blowout accident was built combined with the relevant principles of System Dynamic and based on the analysis of blowout accident main influential factors. The System Dynamic simulation software Vensim was used to simulate the overall process of blowout accident. Monitoring and early warning of oil and gas wells dynamically were achieved. The research results indicate that the blowout accident is caused by the cross-coupling functions of human factors, management factors, environmental factors, equipment factors, and laws and regulations factors.%为动态预测井喷事故发展过程,在分析导致井喷事故主要因素的基础上,结合系统动力学的相关原理,构建井喷事故系统仿真流图,并运用系统动力学仿真软件Vensim对井喷事故的整体流程进行仿真,实现了对油气井安全水平的动态监测和预警.结果表明:井喷事故的发生是由人为因素、管理因素、环境因素、设备因素和法律法规因素四大子系统的交叉耦合作用而导致整个油气井系统的安全水平低于井喷事故的安全临界点所造成的.

  18. Lateral cortex blowout during PFNA blade insertion in a subtrochanteric fracture -Should bone quality determine the type of nail used?

    Institute of Scientific and Technical Information of China (English)

    Sunil Gurpur Kini; Lai Choon Hin; Jikku Haniball

    2015-01-01

    Subtrochanteric fractures pose a therapeutic challenge to the surgeons.With the advent of proximal femoral nails, most of the cases are treated with nailing.Newer nails like proximal femoral nail ant-rotation (PFNA) require the blade to be directly hammered into the bone compared to older nails where the screws are drilled and tapped before insertion.We report one such case in a middle aged female that had intraoperative lateral cortex blowout during PFNA blade insertion in a sclerotic bone.This occurrence to the best of our knowledge is unreported in literature.It is therefore imperative to consider the quality of bone before a decision is made on the implant chosen.

  19. Control of an innovative super-capacitor-powered shape-memory-alloy actuated accumulator for blowout preventer

    Science.gov (United States)

    Chen, Jian; Li, Peng; Song, Gangbing; Ren, Zhang

    2017-01-01

    The design of a super-capacitor-powered shape-memory-alloy (SMA) actuated accumulator for blowout preventer (BOP) presented in this paper featured several advantages over conventional hydraulic accumulators including instant large current drive, quick system response and elimination of need for the pressure conduits. However, the mechanical design introduced two challenges, the nonlinear nature of SMA actuators and the varying voltage provided by a super capacitor, for control system design. A cerebellar model articulation controller (CMAC) feedforward plus PID controller was developed with the aim of compensation for these adverse effects. Experiments were conducted on a scaled down model and experimental results show that precision control can be achieved with the proposed configurations and algorithms.

  20. Driver model used in vehicle tire blow-out simulation%用于爆胎车辆仿真的驾驶员模型

    Institute of Scientific and Technical Information of China (English)

    刘涛; 郭孔辉

    2012-01-01

    分析了驾驶员模型在汽车爆胎仿真应用中存在的问题及爆胎后车辆响应特性的变化,指出爆胎后车辆响应特性发生改变是导致驾驶员模型不能控制爆胎后汽车回到原路径的根本原因。建立了考虑爆胎后车辆左、右转向特性不对称的驾驶员模型,并进行了仿真。最后在原驾驶员模型中加入状态参考器,并对不同车速下的状态参考器参数进行辨识。解决了驾驶员模型在汽车爆胎仿真中的应用问题,为进一步研究汽车爆胎后驾驶员的操作规律及爆胎后汽车的稳定性控制提供了参考。%The problem of application of the driver model in the vehicle tire blow-out simulation and the changes of the vehicle response behavior after the tire blow-out were analyzed,and it was found that vehicle response changes after the tire blow-out are the main cause leading to the problem that the driver model can not drive the vehicle back to the original trajectory.A new driver model considering the fact that the vehicle is characterized by unsymmetric leftward and rightward turning after the tire blow-out was built and its simulation was performed.A vehicle state reference module was embedded in the original driver model and its parameters were identified under different driving speeds.Thus the problem of application of the driver model in the vehicle tire blow-out was solved,providing a reference for the study of driver operation behavior and stability control of the vehicle after tire blow-out.

  1. Modeling the key factors that could influence the diffusion of CO2 from a wellbore blowout in the Ordos Basin, China.

    Science.gov (United States)

    Li, Qi; Shi, Hui; Yang, Duoxing; Wei, Xiaochen

    2016-11-26

    Carbon dioxide (CO2) blowout from a wellbore is regarded as a potential environment risk of a CO2 capture and storage (CCS) project. In this paper, an assumed blowout of a wellbore was examined for China's Shenhua CCS demonstration project. The significant factors that influenced the diffusion of CO2 were identified by using a response surface method with the Box-Behnken experiment design. The numerical simulations showed that the mass emission rate of CO2 from the source and the ambient wind speed have significant influence on the area of interest (the area of high CO2 concentration above 30,000 ppm). There is a strong positive correlation between the mass emission rate and the area of interest, but there is a strong negative correlation between the ambient wind speed and the area of interest. Several other variables have very little influence on the area of interest, e.g., the temperature of CO2, ambient temperature, relative humidity, and stability class values. Due to the weather conditions at the Shenhua CCS demonstration site at the time of the modeled CO2 blowout, the largest diffusion distance of CO2 in the downwind direction did not exceed 200 m along the centerline. When the ambient wind speed is in the range of 0.1-2.0 m/s and the mass emission rate is in the range of 60-120 kg/s, the range of the diffusion of CO2 is at the most dangerous level (i.e., almost all Grade Four marks in the risk matrix). Therefore, if the injection of CO2 takes place in a region that has relatively low perennial wind speed, special attention should be paid to the formulation of pre-planned, emergency measures in case there is a leakage accident. The proposed risk matrix that classifies and grades blowout risks can be used as a reference for the development of appropriate regulations. This work may offer some indicators in developing risk profiles and emergency responses for CO2 blowouts.

  2. Scientific basis for safely shutting in the Macondo Well after the April 20, 2010 Deepwater Horizon blowout.

    Science.gov (United States)

    Hickman, Stephen H; Hsieh, Paul A; Mooney, Walter D; Enomoto, Catherine B; Nelson, Philip H; Mayer, Larry A; Weber, Thomas C; Moran, Kathryn; Flemings, Peter B; McNutt, Marcia K

    2012-12-11

    As part of the government response to the Deepwater Horizon blowout, a Well Integrity Team evaluated the geologic hazards of shutting in the Macondo Well at the seafloor and determined the conditions under which it could safely be undertaken. Of particular concern was the possibility that, under the anticipated high shut-in pressures, oil could leak out of the well casing below the seafloor. Such a leak could lead to new geologic pathways for hydrocarbon release to the Gulf of Mexico. Evaluating this hazard required analyses of 2D and 3D seismic surveys, seafloor bathymetry, sediment properties, geophysical well logs, and drilling data to assess the geological, hydrological, and geomechanical conditions around the Macondo Well. After the well was successfully capped and shut in on July 15, 2010, a variety of monitoring activities were used to assess subsurface well integrity. These activities included acquisition of wellhead pressure data, marine multichannel seismic profiles, seafloor and water-column sonar surveys, and wellhead visual/acoustic monitoring. These data showed that the Macondo Well was not leaking after shut in, and therefore, it could remain safely shut until reservoir pressures were suppressed (killed) with heavy drilling mud and the well was sealed with cement.

  3. Simulation of hydraulic control system of deepwater subsea blowout preventer stacks%深水防喷器组液压控制系统仿真

    Institute of Scientific and Technical Information of China (English)

    葛斐; 郭宏; 李博; 许征

    2014-01-01

    井喷是海洋石油安全钻探生产的重要威胁,人为操作失误或元器件失效都可能导致井喷。防喷器组(BOP)安装在水下井口头,是控制井喷的核心部件,一旦发生井喷,BOP控制系统驱动阀门关闭井口,保证油井的安全。研究了深水防喷器组包括其液压控制系统的功能,在系统仿真软件SimulationX中建立防喷器组的详细模型,包括环形防喷器和闸板防喷器及防喷器组的液压控制系统。仿真分析了1524 m水深下防喷器在不同操作顺序下的封井过程,验证了BOP阀门关闭所用时间符合API规范要求,仿真结果与平台实测数据基本吻合。%The oil and gas industry has been constantly affected by numerous blowouts since it was evolved.Blowout which is caused mainly by kick,leads to loss of valuable reserves and also causes property damage along with loss of life.Subsea blowout preventer (BOP)stack is the key equipment which ensures the safety of wel bore operation.Once the blowout occurs,the control system of BOP wil actuate the corresponding valve and close the preventer within a spec-ified time.This paper investigated the dynamic behavior of hydraulic control system of deepwater subsea BOP stacks.Mathematic simulation models of the ram and annular preventers are estab-lished by using SimulationX software.Different cases are studied to verify whether it is appropri-ate to be operated according to API requirements at the water depth of 1 524 m.

  4. Evaluation of the Biodegradable Plates (PG910/PDO) for Reconstruction of Various Sizes of Orbital Floor Defects in the Blow-Out Fractures.

    Science.gov (United States)

    Tabrizi, Reza; Langner, Nicole J; Pouzesh, Ayatollah; Arabion, Hamidreza

    2013-09-01

    The aim of our study was to evaluate the biodegradable plates (PG910/PDO) for reconstruction of various sizes of the orbital floor defects in the blow-out fractures. We included patients who had an impure blow-out fracture. All patients had a recent trauma and also the surgical intervention was done between 1 and 10 days after trauma. The amount of the orbital floor defect was measured in each case through computed tomography scan. In the surgical intervention, a biodegradable plate was used for the reconstruction of the orbital floor defect along with titanium miniplates used for bone fixation in orbital rim. Due to aesthetic reasons, all patients underwent secondary surgery including removal of titanium miniplates after 18 months. The orbital floor was reevaluated during the removal of the miniplates. The clinical evaluation of remnant defects and biodegradable plates (presence of complete or partial resorption) were documented for each patient. In our study a total of 15 patients (10 males and 5 females) underwent the orbital floor reconstruction using biodegradable miniplates. The size of the orbital floor defects was meanly 3.51 ± 1.29 cm(2). Results demonstrated that 4 out of 15 patients had a remnant defect after resorption of the biodegradable plate. In 10 out of 15 patients, the biodegradable plates completely replaced with fibrous tissues after 18 months. Remaining five patients had partial resorption of plates. There was not any relationship between the defect size and the remnant defects (p > 0.05). A significant relationship was seen between the defect size and the plates' resorption rate (p biodegradable plates is an appropriate option for reconstruction of the orbital floor defects. The defect size does not have any effect on the stability of the plate. However, incomplete plate resorption increases the risk of remnant defects in the orbital floor. The larger defects lead to slow degradation of biodegradable plates.

  5. Application of Fracture Operation MEDPORE Implant in Orbital Blowout%眼眶爆裂性骨折手术MEDPORE植入材料的应用

    Institute of Scientific and Technical Information of China (English)

    邬丹

    2015-01-01

    Objective To investigate the MEDPORE surgery implant material application in the operation of orbital blowout fracture.Methods Retrospective analysis of January 2010 - December 2013 during the application of MEDPORE surgical implant the body material of clinical data of 48 cases of patients with ocular trauma fracture of the orbit.Results All the patients satisfaction after surgery, enophthalmos was corrected, different degrees of diplopia, eye movement to restore normal operation, does not affect vision, follow-up period did not appear the implant or rejection.Conclusion MEDPORE surgical implant material fracture operation is safe and effective in the application of orbital blowout, can effectively prevent postoperative enophthalmos, back and other complications, is the reconstruction of orbital wall ideal biological material.%目的 探讨MEDPORE外科植入体材料在眼眶爆裂性骨折手术中的应用.方法 回顾性分析2010年1月至2013年12月在本院应用MEDPORE外科植入体材料48例眼外伤眶骨骨折患者的临床资料.结果 全部患者术后效果满意,眼球内陷得到不同程度的矫正,复视消失,眼球运动恢复正常,手术不影响视力,出院随访期间未出现植入物脱出或排斥反应.结论 MEDPORE外科植入体材料在眼眶爆裂性骨折手术中的应用安全有效,可以有效防止术后发生眼球下陷、回退等并发症,是重建眶壁理想的生物材料.

  6. Blue foot: a second case of "tattoo blow-out" pigment spread successfully treated with the QS-Nd:YAG laser.

    Science.gov (United States)

    Khetarpal, Shilpi; Molenda, Matthew; Seiger, Eric; Pui, John; Obagi, Suzan

    2010-11-01

    The "tattoo blow-out" phenomenon occurs when tattoo pigments spread outside the border of a tattoo. It is thought to occur when ink is injected too deeply. A healthy 36-year-old female presented to a dermatologist with diffuse spread of tattoo pigment outside the original tattoo that occurred within one day of the placement of a professional tattoo on the dorsum of her foot. The patient was seeking treatment six weeks after the tattoo was placed because she thought the discoloration would improve or resolve on its own, but it worsened. Two punch biopsies were obtained for histology. The biopsy results confirmed granular black pigment consistent with a tattoo in the dermis and subcutaneous fat. The location of pigment was deeper than expected. Due to the success of the QS-Nd:YAG laser in a prior patient, the same treatment was recommended for this patient. The patient received nine laser sessions using the Q-switched laser at 1064 nm, 4 mm, 10 Hz, with gradually increasing energy from 4.5 to 6.0 J/cm2. The pigment outside of the original tattoo borders faded and is barely perceptible. It is important that physicians be made aware of tattoo complications so they can advise patients in regards to the associated risks.

  7. High quality electron bunch generation using a longitudinal density-tailored plasma-based accelerator in the three-dimensional blowout regime

    CERN Document Server

    Xu, X L; An, W; Yu, P; Lu, W; Joshi, C; Mori, W B

    2016-01-01

    The generation of very high quality electron bunches (high brightness and low energy spread) from a plasma-based accelerator in the three-dimensional blowout regime using self-injection in tailored plasma density profiles is analyzed theoretically and with particle-in-cell simulations. The underlying physical mechanism that leads to the generation of high quality electrons is uncovered by tracking the trajectories of the electrons as they cross the sheath and are trapped by the wake. Details on how the intensity of the driver and the density scale-length of the plasma control the ultimate beam quality are described. Three-dimensional particle-in-cell simulations indicate that this concept has the potential to produce beams with peak brightnesses between $10^{20}$ and $10^{21}$ $\\mathrm{A}/\\mathrm{m}^2/\\mathrm{rad}^2$and with absolute projected energy spreads of $\\sim 0.3~\\mathrm{MeV}$ using existing lasers or electron beams to drive nonlinear wakefields.

  8. Successful rescue from cardiac arrest in a patient with postinfarction left ventricular blow-out rupture: "extra-pericardial aortic cannulation" for establishment total cardiopulmonary bypass.

    Science.gov (United States)

    Ohira, Suguru; Yaku, Hitoshi; Nakajima, Shunsuke; Takahashi, Akihiko

    2014-08-01

    We report a quick and simple technique to establish cardiopulmonary bypass (CPB) in a left ventricular (LV) blow-out rupture. A 74-year-old woman with a diagnosis of acute myocardial infarction suddenly collapsed and lost consciousness. A venous-arterial extracorporeal membrane oxygenation (ECMO) device was inserted by femoral cannulation. Emergent median sternotomy was performed. The pericardium was not opened first, and the thymus was divided to expose the ascending aorta just above the pericardial reflection. After placing two purse-string sutures on the distal ascending aorta, a 7-mm aortic cannula (Terumo, Tokyo, Japan) was inserted. The pericardium was then incised. A large volume of blood was expelled from the pericardial space, and CPB was initiated with suction drainage. A two-stage venous drainage cannula was then inserted from the right atrial appendage without hemodynamic collapse. After cardiac arrest, closure of ruptured LV wall and concomitant coronary artery bypass grafting were performed. The patient was weaned from CPB with an intra-aortic balloon pump (IABP) and the previously inserted venous-arterial ECMO. Extra-pericardial aortic cannulation is an effective and reproducible method to prepare for CPB in emergent cases of LV rupture.

  9. 眼眶爆裂性骨折早期立体视觉改变的观察%The stereoscopic vision change in patients with orbital blowout fracture at early stage

    Institute of Scientific and Technical Information of China (English)

    冯洁; 吕学森; 王志安; 胡伟; 王月训; 王盟; 叶青

    2013-01-01

    目的 观察眼眶爆裂性骨折患者早期立体视觉状况.方法 应用计算机断层扫描(CT)测量和计算机软件,对28例眼眶爆裂性骨折进行眼眶扫描,并测量眼眶容积及眼球突出度,采用颜少明《立体视觉检查图》检测其立体视锐度以及同视机三级功能的检测.结果 患眼眼眶容积比对侧健眼眼眶容积增加,其增加量与眼球内陷度呈正相关.早期眼眶爆裂性骨折患者立体视觉有不同程度的下降.结论 眼眶骨折的手术适应证除了考虑眼球内陷、复视等因素之外,立体视锐度的损伤也是手术考量的因素之一.%Objective To observe the stereoscopic vision changes in patients with orbital blowout fracture at early stage.Methods The orbital volume and enophthalmos were measured and calculated with CT measurements and computer software in 28 patients of orbital blowout fracture.The stereoscopic vision of them were examined with stereogram designed by YAN Shao-ming and synoptophone Ⅲ.Results The orbital volume on the damaged side was bigger than the undamaged side.The increase in the amount of orbital volume was positively correlated with amount of eyeball wall invagination.The stereoscopic vision of patients of orbital blowout fracture at early stage would decline at different degrees.Conclusion The extra attention should be paid to the changes of stereopsis during the treatment of orbital blowout fracture.Besides endophthalmos and diplopia,the changes of stereopsis should be one of the indicators for surgeries.

  10. 多级旋流燃烧室贫油熄火特性的实验研究和数值分析%Numerical Analysis and Experimental Investigation of Lean Blowout Performance in A Multi-Swirled Gas Turbine Combustor

    Institute of Scientific and Technical Information of China (English)

    张楷雨; 杨金虎; 刘富强; 刘存喜; 穆勇; 徐纲

    2015-01-01

    Lean blowout is one of the most important parameter to evaluate the performance of the gas turbine combustor.This paper fo-cusing on a multi-swirled gas turbine combustor, verify and improve the classical lean blowout model advanced by A.H.Lefebrve.The influence of swirled atomization on the lean blowout is taken into account to make the improved model more exact and pertinent.A tri-ple-swirled single-sector test combustor is designed for the lean blowout test at atmospheric pressure.The test verifies the improved lean blowout model.Then the character of near lean blowout in the recirculation zone is studied numerically.The study sums up the variety of the character to assist analysis of the lean blowout.%贫油熄火极限是衡量航空发动机燃烧室性能的重要参数之一. 针对多级旋流燃烧室,对经典的Lefebrve熄火模型进行了验证,加入旋流雾化对熄火的影响,结合旋流雾化的燃油平均滴径公式使得计算熄火极限更简便. 设计了一套三级旋流燃烧室单头部实验件,搭建实验台并进行常压熄火实验,结合实验结果对改进的熄火模型进行了验证. 同时对临近熄火过程中燃烧室流场进行了数值模拟,重点对熄火过程中回流区核心内关键特征参数进行了研究,总结了这些特征参数的变化规律,辅助分析燃烧室的贫油熄火极限.

  11. 深水钻井井喷事故情景构建及应急能力评估%Scenario design of blowout accidents in deepwater drilling and emergency capacity assessment

    Institute of Scientific and Technical Information of China (English)

    殷志明; 张红生; 周建良; 李迅科

    2015-01-01

    Deepwater oil and gas development faces enormous risks and challenges. Especially when blowout out of control ac-cident occurs in the development process, the emergency rescue will be very dififcult. Scenario design approach for major accidents is used to build blowout scenarios in the drilling of a deepwater exploratory well in the South China Sea, covering the whole process from overlfow to blowout out of control, ifre and explosion of platform, platform overturn and sinking, underwater emergency well shut-in and relief well digging, spilled oil recycling and ecological restoration. The demands for engineering technology, equipment and staff for the emergency rescue are analyzed and evaluated and suggestions on the research of emergency rescue technology in the next stage in China are provided. The research results can be a reference for the independent building of emergency rescue engineering technique system in well control of deepwater drilling in China.%深水油气开发面临着巨大的风险和挑战,尤其是在油气开发过程中如果发生井喷失控事故,应急救援将十分困难。采用重大事故情景构建方法,建立南中国海某深水探井在钻井期间发生井喷失控事故情景,包括从溢流发生到井喷失控、平台发生火灾爆炸、平台倾覆沉没、水下应急封井及打救援井、溢油回收处理及生态恢复,并对应急救援必须的工程技术、设备、人员等需求进行分析和评估,对我国下一阶段开展应急救援技术研究提出建议。研究结果对我国自主建立深水钻井井控应急救援工程技术体系有一定参考意义。

  12. Research on reliability of subsea blowout preventer based on Markov method%基于马尔可夫方法的水下防喷器可靠性研究

    Institute of Scientific and Technical Information of China (English)

    薛鲁宁; 樊建春; 张来斌

    2012-01-01

    水下防喷器是保障海上钻井安全的关键设备,对其可靠性进行定量评价对井控作业有重要的指导意义.为了弥补现有水下防喷器可靠性评价方法的不足,将水下防喷器的工作状态分为四种,包括无故障可用、关井、井控关键失效及关井时失效.利用Markov方法建立了水下防喷器的Markov模型.通过水下防喷器系统的状态转换图找出了各工作状态的转换关系.通过分析墨西哥湾83口深水井水下防喷器的失效数据,定义了影响水下防喷器可靠性的井控关键失效,并对深水钻井水下防喷器防喷功能的可靠性进行了定量计算.将计算结果与不考虑关井期间的井控关键失效相比较发现,防喷器的防喷失效概率增加了65%.因此传统的定量评价方法可能会得出相对乐观的结论,应在实际生产中给予重视.%Subsea blowout preventer (BOP) is the crucial equipment to ensure offshore drilling safety. Quantitative assessment for its reliability is very meaningful to instruct field well control practice. To cover the limitations of existing reliability assessment methods for subsea BOP system, working states of subsea BOP system were divided into four, which included available with no failure, closed with no failure, failed with no demand, and failed when demanded. Markov model of subsea BOP was built based on Markov method. Markov transition program was presented to find out the transition relationships of the four working states. After analyzing failure statistics of subsea drilling BOP systems installed on 83 deepwater wells in Gulf of Mexico, the definition of well control critical failure for subsea BOP system was defined. Based on the statistics of well control critical failures, reliability of deepwater drilling BOP to prevent blowout was assessed quantitatively. Compared to the result which ignores failures after BOP closed, blowout prevention failure occurrence of subsea BOP system increased

  13. Hess area ratio and the postoperative diplopia in patients undergoing surgery for orbital floor blowout fracture%Hess屏面积比与眶底爆裂性骨折患者术后复视的预后评估

    Institute of Scientific and Technical Information of China (English)

    苏庆; 周军; 傅涛; 卢炜; 王京辉

    2013-01-01

    Objective To investigate the value of the Hess area ratio (HAR%) in predicting postoperative diplopia in patients undergoing surgery for orbital floor blowout fracture.Methods A retrospective analysis was performed on 19 patients with orbital floor blow-out fractures.All patients had diplopia and underwent surgical reconstruction with incision under the eyelashes which was performed by one surgeon within 1 month after injury except 1 case within 2 month.Manual Hess screen test was measured before and 3 months after surgery.Diplopia was checked and the severity was recorded accordingly.Results The postoperative HAR% was significantly improved compared with preoperative HAR% in patients who underwent repair surgery (P < 0.05).All patients with preoperative HAR% > 85% had no postoperative diplopia.Five of 6 (83.33%) patients having a preoperative HAR% < 65% had postoperative diplopia,including 3 patients of Grade Ⅲ diplopia.For the patients with HAR% between 65% and 85%,6 of 8 (75%) had postoperative diplopia,with one of them having Grade Ⅲ diplopia.Conclusions It is effective using the HAR% to convert Hess graphic representation to a numerical value,and feasible to predict surgical outcomes of diplopia in patients undergoing surgery for orbital floor blowout fractures.%目的 探讨Hess屏面积比(HAR%)在评估眶底爆裂性骨折患者术后复视的预后价值.方法 眶底爆裂性骨折19例,手术前均有复视,18例于外伤后1个月内行眶底骨折整复手术,手术由同一术者施行,采用经下睑睫毛下切口.于手术前和手术后3个月分别进行Hess屏检查计算HAR%,并记录复视的程度.结果 各组患者的手术前和手术后的HAR%差异具有统计学意义(P<0.05).在手术后3个月,术前HAR%>85%的患者在眶壁骨折整复术后没有复视;术前HAR%<65%的患者5例(83.33%)术后有复视,其中3例(50%)是Ⅲ级复视;HAR%介于65%和85

  14. Experimental Research of the Acoustic Emission(AE) Characteristics during the Tensile Process of the Shell Material of Blowout Preventer%防喷器壳体材料拉伸过程的声发射特性试验

    Institute of Scientific and Technical Information of China (English)

    赵俊茹; 戴光; 姚鸿滨

    2011-01-01

    In this paper, the tensile damage process of the shell material ZG25GrNiMo of blowout preventer were researched using acoustic emission technique. Analyzed the acoustic emission characteristics in different damage phases of this material were analyzed using parameter analysis and waveform analysis. The result indicated that the acoustic emission characteristics were different in yielding, plastic distortion and rupture process. The differences of frequency spectrums of different damage modes were evident.%采用声发射技术研究了防喷器主壳体材料ZG25GrNiMo的拉伸破坏过程。运用声发射参数分析方法分析了该材料在不同破坏阶段的声发射特性。分析结果表明,在材料屈服、塑性变形及断裂过程中的声发射特性具有明显的不同,且不同损伤模式的信号频谱存在明显的差异。

  15. Development of Deep-water Simulation Experimental Device for Subsea Blowout Preventer Stack Control System%水下防喷器组控制系统深水模拟试验装置研制

    Institute of Scientific and Technical Information of China (English)

    顾和元; 侯国庆; 郭雪; 刘立兵

    2013-01-01

    Reliability of blowout preventer stack control system is highly concerned in subsea oil drilling industry all the time.The subsea stimulation test device for BOP control system and its valves function and reliability was designed and developed,which covers big high pressure cabin used in 3 000 meters deep water for original prototype,and small high pressure cabin used in 4 200 meters deep water for solenoid and deep water function and life test.The design principle of hydraulic system,electricity control system,subsea monitor system is introduced.The test result shows that the test device can meet the requirement for the subsea BOP stack in deep water.%防喷器组控制系统在深水环境的工作可靠性一直是海洋钻井业高度关注的问题.研制了用于水下防喷器组控制系统及其阀件功能测试和可靠性研究的深水模拟试验装置,包括模拟3 000m水深的大型高压舱,用于控制系统原理样机的深水模拟试验;模拟4 200 m水深的小型高压舱,用于深水电磁阀和深水液压阀的深水功能试验和寿命试验.介绍了该试验装置的液控系统、电控系统、水下监控系统的设计原理.试验结果表明:该试验装置能够满足深水防喷器组控制系统的测试要求.

  16. Evaluation of the Customer Satisfaction Index for Wellhead Blowout Preventers of China's Petroleum Industry--A new method based on PLS%中国石油井口防喷器用户满意指数测评 --基于偏最小二乘法

    Institute of Scientific and Technical Information of China (English)

    张鹏; 胡启国; 韩侠; 张斌

    2005-01-01

    This paper establishes an evaluation model of the customer satisfaction index for the wellhead blowout preventers of China's petroleum industry based on evaluation models of the customer satisfaction index at home and aboard, and by considering the consuming situation in China and the features of the China's petroleum industry. For the existence of: (1) multiple correlations among the factors in the model; (2) the variables need to be explained, but that are hard to observe; (3) the customer satisfaction degree of observation variables appears the shape of skewness or two or three peaks, the correlations between the satisfaction index and its factors cannot be described by common multiple regression. This paper uses a partial least squares (PLS) method based on principal components and typical correlative analysis to solve the problem. When PLS is used in the model of the customer satisfaction index of the wellhead blowout preventers, the latent variables and the explanation degree coefficient of the manifest variable to the corresponding latent variables are estimated by PLS path analysis, and the influencing coefficient among the latent variables in the model is estimated by PLS regression analysis. PLS is also be used to calculate and analyze the model and disclose the correlations among the structural variables as well as the correlation between structural variables and its corresponding observation variables, evaluating results of which provide useful information for petroleum industry to improve the product quality and to the enhancement of the customer satisfaction to the product.

  17. Use of SLAB View for simulation of natural gas diffusion in blowouts of sour gas well%SLAB View 软件在含硫天然气井井喷泄漏扩散模拟中的应用

    Institute of Scientific and Technical Information of China (English)

    罗钦; 赵煜晖; 廖柯熹; 向方倩; 周东

    2015-01-01

    This paper describes the SLAB heavy gas dispersion modeling and uses SLAB View to simulate the H2 S diffusion process and hazardous areas in a sour gas well blowouts .It identifies the influence range of H2 S cloud cluster at specified concentration averaging time ,the time w hen the H2 S cloud cluster of specified concentration reaches the furthest distance ,and the furthest diffuse distance in wind direction .The comparison shows that SLAB View offers an easier and faster option to simu‐late leakage and diffusion process during sour gas well blowouts on flat terrains ,and therefore it is a useful tool for the prediction of the diffusion consequence and influence range .%介绍了SLAB重气泄漏扩散模型,并运用SLAB View 软件模拟了某含硫气井发生井喷事故 H2 S云团的扩散过程和危害区域,得出了H2 S云团在指定浓度平均时间下的影响范围,以及指定浓度 H2 S云团出现在最远距离的时间和最远下风向扩散距离。结果表明,SLAB View 软件能方便、快速地模拟平坦地形下含硫天然气井喷泄漏扩散过程,预测事故泄漏扩散后果和影响范围。

  18. 钛网植入治疗眼眶内下壁爆裂性骨折眼球内陷%Titanium mesh implantation for the treatment of enophthalmos caused by blow-out fractures of orbital medial and inferior walls

    Institute of Scientific and Technical Information of China (English)

    于金国; 张静楷; 陈松; 韩琪; 颜华

    2015-01-01

    目的 探讨钛网植入治疗眼眶内下壁爆裂性骨折后眼球内陷的效果.方法 回顾性分析11例(11只眼)眼眶内下壁爆裂性骨折行钛网植入手术的临床资料.术前眼球内陷4.0 ~6.5mm,伴双眼复视者2例,眼球下移位者4例.手术入路为下睑缘切口联合鼻侧皮肤切口,分别于骨膜下植入钛网覆盖眶内壁及下壁骨折缺损区.结果 术后随访7~11个月,眼球内陷均矫正至1 mm以内,2例复视完全消失,4例眼球移位均完全矫正.术后无感染、植人物脱出、排斥或移位等并发症.结论 单纯应用钛网治疗眼眶内下壁爆裂性骨折引起的眼球内陷安全有效,重建眶腔特殊解剖形态、完全还纳脱出的眶内容物是治疗的关键.%Objective To evaluate the effect of titanium mesh implantation for enophthalmos secondary to blow-out fractures of orbital medial and inferior walls.Methods The surgical effects of 11 cases (11 eyes) of blow-out fractures of orbital medial and inferior walls who received titanium mesh implantation for orbital reconstruction were analyzed retrospectively.Preoperatively,all cases showed 4.0 to 6.5mm enophthalmos among whom 2 cases had diplopia and 4 cases had apparent vertical globe dystopia.For all the cases,inferior subciliary approach combined with nasal lateral approach were performed,and 2 titanium mesh plates were implanted under the periosteum to cover the area of the inferior and medial orbital wall fracture respectively in order to reconstruct the normal orbital cavity.Results Postoperatively,after a followed up period of 7-11 months,the enophthalmos of all cases was corrected to less than l mm successfully,the preoperative diplopia disappeared in all the 2 cases,the vertical globe dystopia of 4 cases disappeared totally,and no complication such as infection,extrusion,rejection or migration of the implants occurred.Conclusion Titanium mesh plates implantation only is safe and effective to correct the enophthalmos

  19. Clinical Observation on Vertebrae Implantation via Vertebral Arch Combined with Xugu Huoxue Decation in Treating Thoracolumbar blow-out Fracture%经椎弓根植骨椎体成形内服续骨活血汤治疗胸腰椎爆裂性骨折22例

    Institute of Scientific and Technical Information of China (English)

    林志宏; 洪启东

    2013-01-01

    目的:观察经椎弓根椎体成形内服续骨活血汤治疗胸腰椎爆裂性骨折的临床疗效.方法:自2006年7月至2010年3月期间采用后路椎弓根螺钉固定加经椎弓根植骨椎体成形内服续骨活血汤治疗胸腰椎爆裂性骨折共22例,随访时间为3~20个月,平均12个月,观察术前术后椎体高度、Cobb角及椎管矢状径变化情况.结果:22例患者术后随访未见内固定物失败,椎体矫正度丢失经分析无统计学意义.结论:经椎弓根植骨椎体成形配合续骨活血汤内服能在椎管减压和恢复椎体高度的同时重建了椎体的前中柱,使椎体重获生物学稳定,有效减少内固定应力,降低内固定的松动、断裂和远期椎体高度的丢失,促进骨折的愈合.%Objective: To observe the effects of vertebrae implantation through vertebral arch and Xugu Huoxue Decoction for treatment of thoracolumbar blow-out fracture. Methods: From the July of 2006 to the March of 2009, 22 patients with thoracolumbar blow-out fracture, underwent fixation of posterior vertebral arch by pedicle screw and implantation vertebrae through vertebral arch and took Xugu Huoxue Decoction. They were followed up time between 3 to 20 months, with an average of 12months. The vertebral height before and after the operation, the angle of Cobb, and the changing of the sagittal diameter of vertebral canal were observed. Results: No fixture failure is seen in the 22 patients after operation during the follow-up time. There was no statistical significance in terms of the loss of the vertebral correction. Conclusion: Implantation vertebrae through vertebral arch and Xugu Huoxue Decoction can reconstruct the anterior and middle column, and decompress the vertebral canal and rebuild the vertebral height. As a result, the vertebrae regains its biological stability. Moreover, this treatment has efficiently reduced the internal fixation stress, the risk of the looseness and break of internal fixture and

  20. 计算机辅助快速成型钛网在眼眶爆裂骨折整复中的应用%Orbital blowout fracture reconstruction using titanium mesh pre-bent with computer-aided rapid prototy-ping technology

    Institute of Scientific and Technical Information of China (English)

    张翔; 陈伟; 曹罡; 董震; 徐金科; 刘秉尧; 罗婷苑; 马娟; 张森林

    2016-01-01

    Objective This study was to evaluate the clinical outcomes of orbital blowout fracture repair using the individual titanium mesh bent by computer-aided rapid prototyping . Methods The CT imaging data of 11 cases of orbital blowout fracture were analyzed.The subciliary approach was used for the exposure of the fractures .An appropriate 3D-printed titanium mesh pre-bent by computer-aided rapid prototyping was selected and implanted according to the characteristics of a given defect .The surgical results were analyzed by evaluating diplopia , eyeball movement , enophthalmos , and the position of the titanium mesh and comparing the orbital vol-ume before and after surgery . Results All the operations were successfully accomplished .No remolding or trimming was needed for the pre-bent titanium mesh and implanted titanium mesh was tightly fixed to the orbital wall .The patients were followed up for 3 -12 months, which revealed no symptoms of diplopia in any of the patients . Volumetric analysis showed a significantly reduced orbital volume difference from (2.60 ±0.43) mL preoperatively to (-0.07 ±0.62) mL postoperatively (P<0.01).Enophthalmos was desirably correc-ted, with the enophthalmos difference decreased from (2.35 ±0.81)mm preoperatively to (-0.10 ±0.52) mm postoperatively (P<0.01).No extra-ocular muscle limitation was observed . Conclusion The individual titanium mesh bent with computer-aided rapid prototyping technology can be applied to orbital blowout fracture repair , which may achieve a high success rate of anatomic restoration of the orbital volume and effective prevention of enophthalmos .%目的:由于眶下壁和眶内侧壁的形态不规则,且衬垫的钛网通常是在术中由医师根据经验手工弯制和塑形,难以精确恢复眶壁的原有形态,故整复效果难以得到保障。本研究分析应用计算机辅助快速成型技术预弯的钛网修复眼眶爆裂骨折的临床疗效。方法根据11例眼眶爆裂骨折患

  1. Safety and efficacy analysis of the treatment of orbital blowout fracture with eye movement disorders by Acupuncture%爆裂性眶壁骨折伴眼球运动障碍经针刺治疗的安全性及疗效分析

    Institute of Scientific and Technical Information of China (English)

    赵嫦莹; 黄春荣; 朱彬彬

    2016-01-01

    Objective To explore the clinical effect of eye-acupuncture on eye movement disorders caused by orbital blowout fracture and its security. Methods 70 eyes movement disorder patients with burst orbital wall fracture treated in our hospital from October 201 3 to September of 201 5 were selected and divided into two groups,each group contains 35 cases.The routine group was given routine drug treatment,beside this,we gave the therapy of eye-acupuncture for 30 minutes to the acu-puncture group according to the type to select the corresponding extraocular muscle holes.Both with 1 5 days was for a course of treatment.After two courses,compared the eye movement disorder level changes and the limbus range of movement of the two groups before and after treatment,we evaluated the efficacy based on efficacy standard. Results After treatment,the corneal limbus range of movement were significantly improved of both groups,and the acupuncture group were better than that of the rou-tine group (P <0.05);after treatment,the eye movement disorder rating of the acupuncture group was as follows:the number of level 0,1 ,2,3 was 1 4,1 5,3,3,respectively,among which the number of level 0 was significantly higher than that of the routine group (P <0.05);The total effective rate of the acupuncture group was 91 .43 %,which was significantly higher than that of the control group,the difference was statistically significant (P <0.05). Conclusion Eye-acupuncture may im-prove the corneal limbus range of movement in patients with eye movement disorders caused by orbital blowout fracture.It could promote the recovery of extraocular muscles function and thus lower the level of eye movement disorders.It significantly improves the total efficiency and is worthy of popularization and application clinically.%目的:探讨经针刺治疗爆裂性眶壁骨折伴眼球运动障碍的临床疗效及安全性。方法选取2013年10月—2015年9月在我院接受治疗的70例(70只眼)爆裂性眶

  2. 30 CFR 250.615 - Blowout prevention equipment.

    Science.gov (United States)

    2010-07-01

    ... secondary source of pneumatic supply, must be equipped with manual overrides, or alternately, other devices... first full-opening valve on the choke line and the kill line. (f) The minimum BOP-system components...

  3. Deep-sea benthic footprint of the deepwater horizon blowout.

    Directory of Open Access Journals (Sweden)

    Paul A Montagna

    Full Text Available The Deepwater Horizon (DWH accident in the northern Gulf of Mexico occurred on April 20, 2010 at a water depth of 1525 meters, and a deep-sea plume was detected within one month. Oil contacted and persisted in parts of the bottom of the deep-sea in the Gulf of Mexico. As part of the response to the accident, monitoring cruises were deployed in fall 2010 to measure potential impacts on the two main soft-bottom benthic invertebrate groups: macrofauna and meiofauna. Sediment was collected using a multicorer so that samples for chemical, physical and biological analyses could be taken simultaneously and analyzed using multivariate methods. The footprint of the oil spill was identified by creating a new variable with principal components analysis where the first factor was indicative of the oil spill impacts and this new variable mapped in a geographic information system to identify the area of the oil spill footprint. The most severe relative reduction of faunal abundance and diversity extended to 3 km from the wellhead in all directions covering an area about 24 km(2. Moderate impacts were observed up to 17 km towards the southwest and 8.5 km towards the northeast of the wellhead, covering an area 148 km(2. Benthic effects were correlated to total petroleum hydrocarbon, polycyclic aromatic hydrocarbons and barium concentrations, and distance to the wellhead; but not distance to hydrocarbon seeps. Thus, benthic effects are more likely due to the oil spill, and not natural hydrocarbon seepage. Recovery rates in the deep sea are likely to be slow, on the order of decades or longer.

  4. Sedimentation Pulse in the NE Gulf of Mexico following the 2010 DWH Blowout

    NARCIS (Netherlands)

    Brooks, G.R.; Larson, R.A.; Schwing, P.T.; Romero, I.; Moore, C.; Reichart, G.-J.; Jilbert, T.; Chanton, J.P.; Hastings, D.W.; Overholt, W.A.; Marks, K.P.; Kostka, J.E.; Holmes, C.W.; Hollander, D.

    2015-01-01

    The objective of this study was to investigate the impacts of the Deepwater Horizon (DWH) oil discharge at the seafloor as recorded in bottom sediments of the DeSoto Canyon region in the northeastern Gulf of Mexico. Through a close coupling of sedimentological, geochemical, and biological approaches

  5. Sedimentation Pulse in the NE Gulf of Mexico following the 2010 DWH Blowout.

    Directory of Open Access Journals (Sweden)

    Gregg R Brooks

    Full Text Available The objective of this study was to investigate the impacts of the Deepwater Horizon (DWH oil discharge at the seafloor as recorded in bottom sediments of the DeSoto Canyon region in the northeastern Gulf of Mexico. Through a close coupling of sedimentological, geochemical, and biological approaches, multiple independent lines of evidence from 11 sites sampled in November/December 2010 revealed that the upper ~1 cm depth interval is distinct from underlying sediments and results indicate that particles originated at the sea surface. Consistent dissimilarities in grain size over the surficial ~1 cm of sediments correspond to excess (234Th depths, which indicates a lack of vertical mixing (bioturbation, suggesting the entire layer was deposited within a 4-5 month period. Further, a time series from four deep-sea sites sampled up to three additional times over the following two years revealed that excess (234Th depths, accumulation rates, and (234Th inventories decreased rapidly, within a few to several months after initial coring. The interpretation of a rapid sedimentation pulse is corroborated by stratification in solid phase Mn, which is linked to diagenesis and redox change, and the dramatic decrease in benthic formanifera density that was recorded in surficial sediments. Results are consistent with a brief depositional pulse that was also reported in previous studies of sediments, and marine snow formation in surface waters closer to the wellhead during the summer and fall of 2010. Although sediment input from the Mississippi River and advective transport may influence sedimentation on the seafloor in the DeSoto Canyon region, we conclude based on multidisciplinary evidence that the sedimentation pulse in late 2010 is the product of marine snow formation and is likely linked to the DWH discharge.

  6. ROV: improving remotely operated vehicle (ROV) intervention capabilities for blowout preventer override systems

    Energy Technology Data Exchange (ETDEWEB)

    Lazar, Stephen [Christopher S. Mancini, Tomball, TX (United States)

    2012-07-01

    Events during 2010 have focused attention on increased ROV/BOP Intervention capabilities and standardization of BOP/ROV interfaces in the oil and gas offshore industry. Currently no enforced set standards for ROV intervention panels or manifold types for use on BOP Override systems are specified. The industry offers multiple configurations at present. This abstract will discuss the advantages and disadvantages of the various configurations in existence, trending toward suggested industry standards taking shape as requirements in the near term. Standards for the offshore industry or a set specification must be made to increase safety and functionality of BOP control systems. To date, ROV override capabilities have been added to existing engineered BOP systems. BOP designed closing times were not a critical consideration, only that the access was there to allow for ROV override. Increased ROV flow and pressure capabilities: no current minimum flow requirements for Emergency BOP Override pumps are established. Based on stack valving and configuration, a minimum, 7 gpm may be required to shift valving fully to allow BOP operator function. IADC/API minimum requirements may be proposed at 10 gpm at 3000psi. Based on shear pressures exceeding 3000psi, pressures of 5000psi should be considered. Current intervention skids/pump capabilities will be required if ROVs must achieve API 16D BOP minimum closing times. Remote or isolated accumulation for increased intervention capabilities offers possibilities when ANY ROV of opportunity can trigger a function (such as small inspection type ROVs). Increased volumes will be required. This is critical in functioning stack rams with an ROV of opportunity to achieve API 16D closing times. We now understand that higher flows and pressures are required along with standardization of stab types. Current recommendations: API 17H Hi-Flow manifolds should be added to essential ROV overrides. ROV skids will have a minimum requirement of 10gpm at 3000psi, but should have capabilities to achieve 5000psi and carry enough fluid volume to perform sub sea BOP ram function. Also, any additional isolated accumulator volume would be tied to ANY ROV of opportunity to override the BOP in an emergency situation. (author)

  7. Improved Correlation for Blowout of Bluff-body Stabilized Flames (Preprint)

    Science.gov (United States)

    2012-04-01

    time scale is defined as an ignition delay: ign ign U DDa τ = , (3) Ozawa (1971) authored an excellent review of the early work in lean...struts with direct injection into the wake zone. They also identified a Damköhler number that is different from those proposed by Zukoski and Ozawa

  8. Close games versus blowouts: Optimal challenge reinforces one's intrinsic motivation to win.

    Science.gov (United States)

    Meng, Liang; Pei, Guanxiong; Zheng, Jiehui; Ma, Qingguo

    2016-12-01

    When immersed in intrinsically motivating activities, individuals actively seek optimal challenge, which generally brings the most satisfaction as they play hard and finally win. To better simulate real-life scenarios in the controlled laboratory setting, a two-player online StopWatch (SW) game was developed, whose format is similar to that of a badminton tournament. During the game, a male opponent played by a confederate ensured that the same-sex participant paired with him won both matches, one with a wide margin (the lack of challenge condition) and another with a narrow one (the optimal challenge condition). Electrophysiological data were recorded during the entire experiment. An enlarged Stimulus-preceding negativity (SPN) was observed in the optimal challenge condition, indicating a more concentrated anticipatory attention toward the feedback and a stronger intrinsic motivation during close games. Thus, this study provided original neural evidence for predictions of Self-determination theory (SDT) and Flow theory, and confirmed and emphasized the significant role of optimal challenge in promoting one's intrinsic motivation to win.

  9. Changes in the redox state of sediments following the 2010 BP blowout

    Science.gov (United States)

    Hastings, D. W.; Brooks, G.; Hollander, D. J.; Larson, R. A.; Morford, J. L.; Romero, I.; Hammaker, S.; Hogan, A.; Roeder, T. K.

    2012-12-01

    We have collected multi-core sediment cores from over 40 sites along the NE Gulf of Mexico continental slope following the 2010 Deepwater Horizon oil spill. We present the geochemical results from four select sites collected on August 2010, December 2010, February 2011, September 2011, and August 2012. Cores were extruded at 2 mm intervals, and sediments were analyzed for TOC, 13C, carbonate, short-lived radioisotopes (Pb-210, Cs-137, Be-7, Th-234) and grain size. Cores reveal a well-defined, internally stratified dark brown layer in the top 1-6 cm, with finer grain size than underlying sediments. Samples were digested at high temperature and pressure in concentrated nitric acid to dissolve both the oil and authigenic fractions, but not the detrital component. Samples were subsequently analyzed by ICP-MS. Although the Macondo crude oil is slightly enriched in Ni, V, and Co, with concentrations of 2.8, 0.9, and 0.08ppm, respectively, no significant enrichment of these metals is observed in Gulf of Mexico sediments. Sediment mass accumulation rates following the event range from 0.6 - 20 g/cm2/yr, which are one to two orders of magnitude higher than pre-spill rates. Organic and inorganic carbon deposition rates from the 2010 and February 2011 cores are also elevated one to two orders of magnitude. 13C signatures of this recent deposited material are slightly depleted relative to pre-oil event material. Large sedimentation rates, depleted 13C values and lack of bioturbation on the surface of the deep sediments studied supports the hypothesis of a large sea-snow-like blizzard event during the oil-spill in 2010. Bacterially mediated oxidation of organic matter is reflected in a well-established sequence of oxidation-reduction reactions. We exploit redox sensitive trace elements including Mn, Fe, Re, U, Mo, and V to infer changes in the redox state of sediments following this large pulse of organic matter to the seafloor.

  10. Vulnerability and imagination in the Snorre A gas blowout and recovery

    NARCIS (Netherlands)

    Wackers, G.; Coeckelbergh, M.

    2008-01-01

    In 2004, Statoil lost control of a well on the Snorre A TLP on the Norwegian Continental Shelf (NCS) during a slot recovery operation. The platform was engulfed in a cloud of gas, which fortunately did not ignite. Following safety procedures, oil production was shut down and main power was cut. Most

  11. Sedimentation pulse in the NE Gulf of Mexico following the 2010 DWH blowout

    NARCIS (Netherlands)

    Brooks, Gregg R.; Larson, Rebekka A.; Schwing, Patrick T.; Romero, Isabel; Moore, Christopher; Reichart, Gert Jan; Jilbert, Tom; Chanton, Jeff P.; Hastings, David W.; Overholt, Will A.; Marks, Kala P.; Kostka, Joel E.; Holmes, Charles W.; Hollander, David

    2015-01-01

    The objective of this study was to investigate the impacts of the Deepwater Horizon (DWH) oil discharge at the seafloor as recorded in bottom sediments of the DeSoto Canyon region in the northeastern Gulf of Mexico. Through a close coupling of sedimentological, geochemical, and biological approaches

  12. THE USE OF CAD METHODS FOR DESIGNING BLOWOUT PREVENTERS BOP IN OIL INDUSTRY

    Directory of Open Access Journals (Sweden)

    Marius STAN

    2014-05-01

    Full Text Available Best practice design and analysis of operational safety requires CAD modeling of these BOP.The primary objective for this paper was to design and select a suitable BOP system to meet the applications and proposing CAD solutions to improve the operation of the entire safe system. This paper presents and modes of BOP accident with investigation methods CAD

  13. Distinct Bacterial Communities in Surficial Seafloor Sediments Following the 2010 Deepwater Horizon Blowout

    DEFF Research Database (Denmark)

    Yang, Tingting; Speare, Kelly; McKay, Luke

    2016-01-01

    A major fraction of the petroleum hydrocarbons discharged during the 2010 Macondo oil spill became associated with and sank to the seafloor as marine snow flocs. This sedimentation pulse induced the development of distinct bacterial communities. Between May 2010 and July 2011, full-length 16S rRN...

  14. Distinct bacterial communities in surficial seafloor sediments following the 2010 Deepwater Horizon blowout

    Directory of Open Access Journals (Sweden)

    Tingting Yang

    2016-09-01

    Full Text Available A major fraction of the petroleum hydrocarbons discharged during the 2010 Macondo oil spill became associated with and sank to the seafloor as marine snow flocs. This sedimentation pulse induced the development of distinct bacterial communities. Between May 2010 and July 2011, full-length 16S rRNA gene clone libraries demonstrated bacterial community succession in oil-polluted sediment samples near the wellhead area. Libraries from early May 2010, before the sedimentation event, served as the baseline control. Freshly deposited oil-derived marine snow was collected on the surface of sediment cores in September 2010, and was characterized by abundantly detected members of the marine Roseobacter cluster within the Alphaproteobacteria. Samples collected in mid-October 2010 closest to the wellhead contained members of the sulfate-reducing, anaerobic bacterial families Desulfobacteraceae and Desulfobulbaceae within the Deltaproteobacteria, suggesting that the oil-derived sedimentation pulse triggered bacterial oxygen consumption and created patchy anaerobic microniches that favored sulfate-reducing bacteria. Phylotypes of the polycyclic aromatic hydrocarbon-degrading genus Cycloclasticus, previously found both in surface oil slicks and the deep hydrocarbon plume, were also found in oil-derived marine snow flocs sedimenting on the seafloor in September 2010, and in surficial sediments collected in October and November 2010, but not in any of the control samples. Due to the relative recalcitrance and stability of polycyclic aromatic compounds, Cycloclasticus represents the most persistent microbial marker of seafloor hydrocarbon deposition that we could identify in this dataset. The bacterial imprint of the DWH oil spill had diminished in late November 2010, when the bacterial communities in oil-impacted sediment samples collected near the Macondo wellhead began to resemble their pre-spill counterparts and spatial controls. Samples collected in summer of 2011 did not show a consistent bacterial community signature, suggesting that the bacterial community was no longer shaped by the DWH fallout of oil-derived marine snow, but instead by location-specific and seasonal factors.

  15. Three-dimensional oil spill transport and dispersion at sea by an event of blowout

    Directory of Open Access Journals (Sweden)

    Luis Otero-Díaz

    2014-01-01

    Full Text Available Las trayectorias de las gotas simuladas con el modelo 3-D de dispersión de petróleo en la plataforma del mar Caribe colombiano mostraron que las gotas con diámetro de 50 μ m , forman una pluma subsuperficial, la cual es transportada horizontalmente y puede permanecer debajo de la superficie por largo tiempo. Esta pluma podría tener un impacto muy restringido, porque la dispersión es controlada solamente por las corrientes oceánicas, las cuales a 1000 metros de profundidad, tienen baja intensidad y son poco turbulentas. En este caso, la pluma formada permanece atrapada a 1000 metros de profundidad, no poniendo en riesgo la costa Caribe. En contraste, las gotas con diámetros de 250 μ m , 1mm y 10 mm, se elevaron rápidamente a la superficie, aun con diferentes velocidades (6, 10, 20 ms-1.

  16. Observations of quasi-periodic phenomena associated with a large blowout solar jet

    OpenAIRE

    Morton, Richard; Srivastava, Abhishek; Erdélyi, Robert

    2012-01-01

    Aims: A variety of periodic phenomena have been observed in conjunction with large solar jets. We aim to find further evidence for (quasi-)periodic behaviour in solar jets and determine what the periodic behaviour can tell us about the excitation mechanism and formation process of the large solar jet. \\ud \\ud Methods: Using the 304 Å (He-II), 171 Å (Fe IX), 193 Å (Fe XII/XXIV) and 131 Å (Fe VIII/XXI) filters onboard the Solar Dynamic Observatory (SDO) Atmospheric Imaging Assembly (AIA), we in...

  17. Multidimensional Plasma Wake Excitation in the Non-linear Blowout Regime

    CERN Document Server

    Vieira, J; Silva, L O

    2016-01-01

    Plasma accelerators can sustain very high acceleration gradients. They are promising candidates for future generations of particle accelerators for sev- eral scientific, medical and technological applications. Current plasma based acceleration experiments operate in the relativistic regime, where the plasma response is strongly non-linear. We outline some of the key properties of wake- field excitation in these regimes. We outline a multidimensional theory for the excitation of plasma wakefields in connection with current experiments. We then use these results and provide design guidelines for the choice of laser and plasma parameters ensuring a stable laser wakefield accelerator that maximizes the quality of the accelerated electrons. We also mention some of the future challenges associated with this technology.

  18. Evidence for Blow-out in the Low-mass Dwarf Galaxy Holmberg I

    CERN Document Server

    Ott, J; Brinks, E; Van Dyk, S D; Dirsch, B; Klein, U; Ott, Juergen; Walter, Fabian; Brinks, Elias; Dyk, Schuyler D. Van; Dirsch, Boris; Klein, Ulrich

    2001-01-01

    We present radio and optical observations of Holmberg I (HoI), a member of the M81 group of galaxies (distance 3.6Mpc). HoI is a low-mass, low surface- brightness dwarf galaxy. High-resolution multi-array VLA HI observations reveal a supergiant shell (diameter: 1.7 kpc) which covers about half the optical extent of HoI and which comprises 75% of the total HI content (total HI mass: 1.1 10^8 M_o). We set a tentative upper limit to the dark matter content of < 3.1 10^8 M_o. The HI data are complemented by deep, optical UBV(RI)_c and Halpha observations obtained at the Calar Alto 2.2m telescope. We find M_HI/L_B = 1.1 M_o/L_B_o. The total visible (stars plus gas) mass of HoI adds up to 2.4 10^8 M_o. This leads to a total mass of < 5.5 10^8 M_o. The origin of HoI's peculiar HI morphology is discussed in terms of a supergiant shell created by strong stellar winds and supernova explosions (energy: equiv. 20-260 type II SN; age: 80+-20 Myr). The morphological center of HoI is offset by 0.75 kpc with respect to...

  19. Hydrocarbons in Deep-Sea Sediments following the 2010 Deepwater Horizon Blowout in the Northeast Gulf of Mexico.

    Directory of Open Access Journals (Sweden)

    Isabel C Romero

    Full Text Available The Deepwater Horizon (DWH spill released 4.9 million barrels of oil into the Gulf of Mexico (GoM over 87 days. Sediment and water sampling efforts were concentrated SW of the DWH and in coastal areas. Here we present geochemistry data from sediment cores collected in the aftermath of the DWH event from 1000-1500 m water depth in the DeSoto Canyon, NE of the DWH wellhead. Cores were analyzed at high-resolution (at 2 mm and 5 mm intervals in order to evaluate the concentration, composition and input of hydrocarbons to the seafloor. Specifically, we analyzed total organic carbon (TOC, aliphatic, polycyclic aromatic hydrocarbon (PAHs, and biomarker (hopanes, steranes, diasteranes compounds to elucidate possible sources and transport pathways for deposition of hydrocarbons. Results showed higher hydrocarbon concentrations during 2010-2011 compared to years prior to 2010. Hydrocarbon inputs in 2010-2011 were composed of a mixture of sources including terrestrial, planktonic, and weathered oil. Our results suggest that after the DWH event, both soluble and highly insoluble hydrocarbons were deposited at enhanced rates in the deep-sea. We proposed two distinct transport pathways of hydrocarbon deposition: 1 sinking of oil-particle aggregates (hydrocarbon-contaminated marine snow and/or suspended particulate material, and 2 advective transport and direct contact of the deep plume with the continental slope surface sediments between 1000-1200 m. Our findings underline the complexity of the depositional event observed in the aftermath of the DWH event in terms of multiple sources, variable concentrations, and spatial (depth-related variability in the DeSoto Canyon, NE of the DWH wellhead.

  20. Hydrocarbons in Deep-Sea Sediments following the 2010 Deepwater Horizon Blowout in the Northeast Gulf of Mexico

    Science.gov (United States)

    Romero, Isabel C.; Schwing, Patrick T.; Brooks, Gregg R.; Larson, Rebekka A.; Hastings, David W.; Ellis, Greg; Goddard, Ethan A.; Hollander, David J.

    2015-01-01

    The Deepwater Horizon (DWH) spill released 4.9 million barrels of oil into the Gulf of Mexico (GoM) over 87 days. Sediment and water sampling efforts were concentrated SW of the DWH and in coastal areas. Here we present geochemistry data from sediment cores collected in the aftermath of the DWH event from 1000 – 1500 m water depth in the DeSoto Canyon, NE of the DWH wellhead. Cores were analyzed at high-resolution (at 2 mm and 5 mm intervals) in order to evaluate the concentration, composition and input of hydrocarbons to the seafloor. Specifically, we analyzed total organic carbon (TOC), aliphatic, polycyclic aromatic hydrocarbon (PAHs), and biomarker (hopanes, steranes, diasteranes) compounds to elucidate possible sources and transport pathways for deposition of hydrocarbons. Results showed higher hydrocarbon concentrations during 2010-2011 compared to years prior to 2010. Hydrocarbon inputs in 2010-2011 were composed of a mixture of sources including terrestrial, planktonic, and weathered oil. Our results suggest that after the DWH event, both soluble and highly insoluble hydrocarbons were deposited at enhanced rates in the deep-sea. We proposed two distinct transport pathways of hydrocarbon deposition: 1) sinking of oil-particle aggregates (hydrocarbon-contaminated marine snow and/or suspended particulate material), and 2) advective transport and direct contact of the deep plume with the continental slope surface sediments between 1000-1200 m. Our findings underline the complexity of the depositional event observed in the aftermath of the DWH event in terms of multiple sources, variable concentrations, and spatial (depth-related) variability in the DeSoto Canyon, NE of the DWH wellhead. PMID:26020923

  1. Simulating Gas-Liquid-Water Partitioning and Fluid Properties of Petroleum under Pressure: Implications for Deep-Sea Blowouts.

    Science.gov (United States)

    Gros, Jonas; Reddy, Christopher M; Nelson, Robert K; Socolofsky, Scott A; Arey, J Samuel

    2016-07-19

    With the expansion of offshore petroleum extraction, validated models are needed to simulate the behaviors of petroleum compounds released in deep (>100 m) waters. We present a thermodynamic model of the densities, viscosities, and gas-liquid-water partitioning of petroleum mixtures with varying pressure, temperature, and composition based on the Peng-Robinson equation-of-state and the modified Henry's law (Krychevsky-Kasarnovsky equation). The model is applied to Macondo reservoir fluid released during the Deepwater Horizon disaster, represented with 279-280 pseudocomponents, including 131-132 individual compounds. We define >n-C8 pseudocomponents based on comprehensive two-dimensional gas chromatography (GC × GC) measurements, which enable the modeling of aqueous partitioning for n-C8 to n-C26 fractions not quantified individually. Thermodynamic model predictions are tested against available laboratory data on petroleum liquid densities, gas/liquid volume fractions, and liquid viscosities. We find that the emitted petroleum mixture was ∼29-44% gas and ∼56-71% liquid, after cooling to local conditions near the broken Macondo riser stub (∼153 atm and 4.3 °C). High pressure conditions dramatically favor the aqueous dissolution of C1-C4 hydrocarbons and also influence the buoyancies of bubbles and droplets. Additionally, the simulated densities of emitted petroleum fluids affect previous estimates of the volumetric flow rate of dead oil from the emission source.

  2. Hydrocarbons in Deep-Sea Sediments following the 2010 Deepwater Horizon Blowout in the Northeast Gulf of Mexico

    OpenAIRE

    Romero, Isabel C.; Patrick T Schwing; Gregg R Brooks; Larson, Rebekka A.; Hastings, David W.; Greg Ellis; Goddard, Ethan A.; David J Hollander

    2015-01-01

    The Deepwater Horizon (DWH) spill released 4.9 million barrels of oil into the Gulf of Mexico (GoM) over 87 days. Sediment and water sampling efforts were concentrated SW of the DWH and in coastal areas. Here we present geochemistry data from sediment cores collected in the aftermath of the DWH event from 1000 – 1500 m water depth in the DeSoto Canyon, NE of the DWH wellhead. Cores were analyzed at high-resolution (at 2 mm and 5 mm intervals) in order to evaluate the concentration, compositio...

  3. Hydrocarbons in Deep-Sea Sediments following the 2010 Deepwater Horizon Blowout in the Northeast Gulf of Mexico.

    Science.gov (United States)

    Romero, Isabel C; Schwing, Patrick T; Brooks, Gregg R; Larson, Rebekka A; Hastings, David W; Ellis, Greg; Goddard, Ethan A; Hollander, David J

    2015-01-01

    The Deepwater Horizon (DWH) spill released 4.9 million barrels of oil into the Gulf of Mexico (GoM) over 87 days. Sediment and water sampling efforts were concentrated SW of the DWH and in coastal areas. Here we present geochemistry data from sediment cores collected in the aftermath of the DWH event from 1000-1500 m water depth in the DeSoto Canyon, NE of the DWH wellhead. Cores were analyzed at high-resolution (at 2 mm and 5 mm intervals) in order to evaluate the concentration, composition and input of hydrocarbons to the seafloor. Specifically, we analyzed total organic carbon (TOC), aliphatic, polycyclic aromatic hydrocarbon (PAHs), and biomarker (hopanes, steranes, diasteranes) compounds to elucidate possible sources and transport pathways for deposition of hydrocarbons. Results showed higher hydrocarbon concentrations during 2010-2011 compared to years prior to 2010. Hydrocarbon inputs in 2010-2011 were composed of a mixture of sources including terrestrial, planktonic, and weathered oil. Our results suggest that after the DWH event, both soluble and highly insoluble hydrocarbons were deposited at enhanced rates in the deep-sea. We proposed two distinct transport pathways of hydrocarbon deposition: 1) sinking of oil-particle aggregates (hydrocarbon-contaminated marine snow and/or suspended particulate material), and 2) advective transport and direct contact of the deep plume with the continental slope surface sediments between 1000-1200 m. Our findings underline the complexity of the depositional event observed in the aftermath of the DWH event in terms of multiple sources, variable concentrations, and spatial (depth-related) variability in the DeSoto Canyon, NE of the DWH wellhead.

  4. Analysis on dispersion of H2S during well blowout%井喷硫化氢扩散分析

    Institute of Scientific and Technical Information of China (English)

    席学军; 邓云峰

    2007-01-01

    井喷有毒气体扩散对周围居民的危害很大[1],由于井场所位于的山区地形下垫面特殊,气体扩散的过程比较复杂,无法用普通的烟羽模式进行模拟,本文采用大涡模型以及贴体网格技术、卫星遥感技术,对某地区发生泄漏进行研究并进行三维数值模拟,模拟结果显示了气体扩散的时空分布以及对人员的危害,通过模拟结果,可以对井场地区的安全情况作出评价,能够对应急人员疏散策略及安全区域规划的制定提供帮助.

  5. The composite form of the supernova remnant 3C 400.2: two interacting supernova remnants or a single supernova remnant with a blow-out?

    Directory of Open Access Journals (Sweden)

    Patricia Ambrocio-Cruz

    2006-01-01

    Full Text Available 3C 400.2 es un remanente de supernova galáctico que presenta una morfología que asemeja dos cascarones de diámetros diferentes que se traslapan. Estudiamos la cinemática de ambos cascarones para saber si esta morfología especial es debida al resultado de dos explosiones de supernova diferentes, o bien, a la explosión de una única supernova en un medio que tenga un gradiente de densidad abrupto. Los datos cinemáticos concuerdan mejor con la segunda hipótesis.

  6. The composite form of the supernova remnant 3C 400.2: two interacting supernova remnants or a single supernova remnant with a blow-out?

    OpenAIRE

    Patricia Ambrocio-Cruz; Margarita Rosado; Eduardo de la Fuente

    2006-01-01

    3C 400.2 es un remanente de supernova galáctico que presenta una morfología que asemeja dos cascarones de diámetros diferentes que se traslapan. Estudiamos la cinemática de ambos cascarones para saber si esta morfología especial es debida al resultado de dos explosiones de supernova diferentes, o bien, a la explosión de una única supernova en un medio que tenga un gradiente de densidad abrupto. Los datos cinemáticos concuerdan mejor con la segunda hipótesis.

  7. 井喷后含硫气体的扩散模拟分析%Dispersion Simulation Analysis of Sulfur Gases Content in Blowout Accident

    Institute of Scientific and Technical Information of China (English)

    朱红钧; 林元华; 王怡; 鲜奇彪; 严仁田; 李强

    2010-01-01

    含硫气井井喷后,H2S气体在空间的迁移扩散受井口压强、地形、气象等多因素影响,准确预测其在空间中的浓度分布,是制定安全应急措施的关键.为此,采用CFD方法对不同井口压强和不同风速条件下井喷后含硫气体的扩散情况进行模拟,获得了H2S气体在计算区域内的浓度分布以及危险区域范围.静风时,在喷口附近及垂直上方H2S浓度很高,安全区域位于井口两侧,占整个计算空间的比例较小;有风时,H2S危险区域明显右倾,井口压强越大,气体扩散高度越高.模拟计算结果可为气井风险评估、应急处理、事故分析提供一定的参考.

  8. Assessment of impacts and evaluation of restoration methods on areas affected by a well blowout, Naval Petroleum Reserve No. 1, California

    Energy Technology Data Exchange (ETDEWEB)

    Warrick, G.D.; Kato, T.T.; Phillips, M.V. [and others

    1996-12-01

    In June 1994, an oil well on Naval Petroleum Reserve No. 1 blew-out and crude oil was deposited downwind. After the well was capped, information was collected to characterize the release and to assess effects to wildlife and plants. Oil residue was found up to 13.7 km from the well site, but deposition was relatively light and the oil quickly dried to form a thin crust on the soil surface. Elevated levels of hydrocarbons were found in livers collected from Heermann`s kangaroo rats (Dipodomys heermanni) from the oiled area but polycyclic aromatic hydrocarbons (known carcinogens or mutagens) were not detected in the livers. Restoration techniques (surface modification and bioremediation) and natural recovery were evaluated within three portions of the oiled area. Herbaceous cover and production, and survival and vigor of desert saltbush (Atriplex polycarpa) were also monitored within each trapping grid.

  9. Numerical Simulation Preview on Release Dispersion of the H2S Blowout%关于井喷H2S扩散数值模拟初步研究

    Institute of Scientific and Technical Information of China (English)

    席学军

    2005-01-01

    井喷发生时,在复杂地形和气象条件下,用普通方法很难精确计算出场的时空分布.CFD(Computational Fluid Dynamics)方法虽然理论上能够计算,但是受限于目前的数学基础以及计算机计算能力的限制,CFD方法还很难在大范围地域条件下得到推广和应用.本文的目标就是如何在这些条件下采用合理的假设改进CFD算法,计算出井喷发生后的场的时空分布.在算例中,本文计算维多辛斯基曲线喷嘴射流的流场分布,并与实验值比较.结果证明,所采用的模型和计算方法的计算结果与实际情况基本相符,模型和计算方法可以适用井喷的数值模拟.

  10. 海洋钻井平台井喷硫化氢扩散规律研究%Study on H2S dispersion from well blowout in offshore drilling platform

    Institute of Scientific and Technical Information of China (English)

    邓海发; 陈国明; 朱渊; 宋林松

    2010-01-01

    针对海洋酸性气田开发过程中的井喷硫化氢扩散问题,以计算流体力学(CFD)为理论基础,建立一套数值模拟方案和毒害评价模型.选取静风、平均风速和季风风速3种典型环境风速条件,对左舷、右舷、船艏、船艉4个来风方向的硫化氢扩散过程进行模拟,分析了硫化氢扩散的时空分布以及风速对硫化氢扩散的影响作用.结果表明,静风条件下,硫化氢对平台空间危害最为严重;有风条件下,船艏和船艉来风,平台空间危害较为严重;其他方向来风时,硫化氢对平台空间区域危害较小.风速越大,硫化氢对平台空间的危害程度越小.最后,据此提出了相应的应对措施.

  11. Dispersant Effectiveness, In-Situ Droplet Size Distribution and Numerical Modeling to Assess Subsurface Dispersant Injection as a Deepwater Blowout Oil Spill Response Option and Evaluation of Oil Fluorescence Characteristics to Improve Forensic Response Tools

    Science.gov (United States)

    This report summarizes two projects covered under an Interagency Agreement between the Bureau of Safety and Environmental Enforcement (BSEE) and the U.S. Environmental Protection Agency (EPA) in collaboration with the Bedford Institute of Oceanography, Department of Fisheries and...

  12. The 2010 Oil Spill: MMS/BOEMRE and NEPA

    Science.gov (United States)

    2010-08-19

    of information if it does not display a currently valid OMB control number. 1. REPORT DATE 19 AUG 2010 2. REPORT TYPE 3. DATES COVERED 00-00-2010...Research Service 8 The Multisale EIS includes a discussion of blowouts as a Loss of Well Control (LWC), of which a blowout is the most severe form...the project involves a subsea blowout preventer. Congressional Attention to Categorical Exclusions Congress has also focused on the use of CEs for

  13. 75 FR 54370 - BOEMRE Information Collection Activity: 1010-0183, Information Requirements for Exploration Plans...

    Science.gov (United States)

    2010-09-07

    ... techniques sufficient to prevent or minimize the likelihood of blowouts, loss of well control, fires... review the data submitted to analyze future activities under Exploration Plans (EPs), Development...

  14. Short-term effects of oil ingestion on American kestrels (Falco sparverius)

    Science.gov (United States)

    Pattee, O.H.; Franson, J.C.

    1982-01-01

    The Mexican Ixtoc oil well blowout resulted in extensive oil contamination along the Texas Gulf coast. This oil posed a potential hazard to migrating birds including the endangered peregrine falcon (Falco peregrinus). Laboratory tests with the American kestrel (Falco sparverius) indicated that the oil: water mixture gathered at the surface of the blowout site posed little acute hazard to falcons.

  15. 76 FR 14980 - BOEMRE Information Collection Activity: 1010-0185, Increased Safety Measures for Oil and Gas...

    Science.gov (United States)

    2011-03-18

    ... Measures for Oil and Gas Drilling, Well-Completion, and Well-Workover Operations. OMB Control Number: 1010... sufficient to prevent or minimize the likelihood of blowouts, loss of well control, fires, spillages... certain drilling requirements. This includes requirements related to subsea and surface blowout...

  16. 78 FR 10685 - Reports, Forms, and Recordkeeping Requirements: Agency Information Collection Activity Under OMB...

    Science.gov (United States)

    2013-02-14

    ... with a 60-day comment period was published on December 11, 2012 [FR Doc. 2012-29844, Vol. 77, No. 238... skidding, hydroplaning, longer stopping distances, and crashes due to flat tires and blowouts. In an...

  17. 75 FR 54363 - BOEMRE Information Collection Activity: 1010-0142, Decommissioning Activities, Extension of a...

    Science.gov (United States)

    2010-09-07

    ... information. SUPPLEMENTARY INFORMATION: Title: 30 CFR 250, subpart Q, Decommissioning Activities. OMB Control... prevent or minimize the likelihood of blowouts, loss of well control, fires, spillages, physical... equipment and subsea protective covering; or other departures. Subtotal 50 responses 150...

  18. Final Report: Experimental Investigation of Nonlinear Plasma Wake-Fields

    Energy Technology Data Exchange (ETDEWEB)

    Rosenzweig, J.

    1997-10-31

    We discuss the exploration of the newly proposed blowout regime of the plasma wakefield accelerator and advanced photoinjector technology for linear collider applications. The plasma wakefield experiment at ANL produced several ground-breaking results in the physics of the blowout regime. The photoinjector R and D effort produced breakthroughs in theoretical, computational, and experimental methods in high brightness beam physics. Results have been published.

  19. The surge-like eruption of a miniature filament

    Institute of Scientific and Technical Information of China (English)

    Jia-Yan Yang; Yun-Chun Jiang; Dan yang; Yi Bi; Bo Yang; Rui-Sheng Zheng; Jun-Chao Hong

    2012-01-01

    We report on the rare eruption of a miniature Hα filament that took the form of a surge.The filament first underwent a full development within 46 min and then began to erupt 9 min later,followed by a compact,impulsive X-ray class M2.2 flare with a two-ribbon nature only at the early eruption phase.During the eruption,its top rose,whereas the two legs remained rooted in the chromosphere and showed little swelling perpendicular to the rising direction.This led to a surge-like eruption with a narrow angular extent.Similar to the recent observations for standard and blowout X-ray jets by Moore et al.,we thus define it as a "blowout Hα surge." Furthermore,our observations showed that the eruption was associated with (1) a coronal mass ejection guided by a pre-existing streamer,(2) abrupt,significant,and persistent changes in the photospheric magnetic field around the filament,and (3) a sudden disappearance of a small pore.These observations thus provide evidence that a blowout surge is a small-scale version of a large-scale filament eruption in many aspects.Our observations further suggest that at least part of the Hα surges belong to blowout-type cases,and the exact distinction between the standard and blowout Hα surges is important in understanding their different origins and associated eruptive phenomena.

  20. Hyperchaos-chaos-Hyperchaos Transition in a Class of On-Off Intermittent Systems Driven by a Family of Generalized Lorenz Systems

    Institute of Scientific and Technical Information of China (English)

    ZHOU Qian; CHEN Zeng-Qiang; YUAN Zhu-Zhi

    2008-01-01

    Blowout bifurcation in nonlinear systems occurs when a chaotic attractor lying in some symmetric subspace becomes transversely unstable. A class of five-dimensional continuous autonomous systems is considered, in which a two-dimensional subsystem is driven by a family of generalized Lorenz systems. The systems have some common dynamical characters. As the coupling parameter changes, blowout bifurcations occur in these systems and brings on change of the systems' dynamics. After the bifurcation the phenomenon of on-ff intermittency appears. It is observed that the systems undergo a symmetric hyperchaos-chaos hyperchaos transition via or after blowout bifurcations. An example of the systems is given, in which the drive system is the Chen system. We investigate the dynamical behaviour before and after the blowout bifurcation in the systems and make an analysis of the transition process. It is shown that in such coupled chaotic continuous systems, blowout bifurcation leads to a transition from chaos to hyperchaos for the whole systems, which provides a route to hyperchaos.

  1. The influence of dust grain porosity on the analysis of debris disc observations

    CERN Document Server

    Brunngräber, Robert; Kirchschlager, Florian; Ertel, Steve

    2016-01-01

    Debris discs are often modelled assuming compact dust grains, but more and more evidence for the presence of porous grains is found. We aim at quantifying the systematic errors introduced when modelling debris discs composed of porous dust with a disc model assuming spherical, compact grains. We calculate the optical dust properties derived via the fast, but simple effective medium theory. The theoretical lower boundary of the size distribution -- the so-called 'blowout size' -- is compared in the cases of compact and porous grains. Finally, we simulate observations of hypothetical debris discs with different porosities and feed them into a fitting procedure using only compact grains. The deviations of the results for compact grains from the original model based on porous grains are analysed. We find that the blowout size increases with increasing grain porosity up to a factor of two. An analytical approximation function for the blowout size as a function of porosity and stellar luminosity is derived. The ana...

  2. 混沌同步稳定性分析及在一个二维广告竞争模型中的应用%Analysis of Chaotic Synchronization Stability and Its Application to a Two-dimensional Advertising Competing Model

    Institute of Scientific and Technical Information of China (English)

    齐洁; 汪定伟

    2005-01-01

    A class of map in which chaotic synchronization can occur is defined. The transverse Lyapunov exponents are used to determine the stability of synchronized trajectories. Some complex phenomena closely related to chaotic synchronization, namely riddled basin, riddling bifurcation and blowout bifurcation are theoretically analyzed. Riddling bifurcation and blowout bifurcation may change the synchronization stability of the system. And two types of riddled basins, i.e., global riddled basin and local riddled basin, may come into being after riddling bifurcation. An advertising competing model based on Vidale-Wolfe model is proposed and analyzed by the above theories at the end of the paper.

  3. Capping stack: An industry in the making

    Institute of Scientific and Technical Information of China (English)

    Jack Chen; Li Xunke; Xie Wenhui; Kang Yongtian

    2013-01-01

    This paper gives an overview of recent development of the marine well containment system (MWCS)after BP Macondo subsea well blowout occurred on April 20,2010 in the Gulf of Mexico.Capping stack,a hardware utilized to contain blowout well at or near the wellhead is the center piece of MWCS.Accessibility to the dedicated capping stacks is gradually becoming a pre-requirement to obtain the permit for offshore drilling/workover,and the industry for manufacturing,maintenance,transportation and operation of the capping stack is in the making.

  4. Characterization of complexities in combustion instability in a lean premixed gas-turbine model combustor.

    Science.gov (United States)

    Gotoda, Hiroshi; Amano, Masahito; Miyano, Takaya; Ikawa, Takuya; Maki, Koshiro; Tachibana, Shigeru

    2012-12-01

    We characterize complexities in combustion instability in a lean premixed gas-turbine model combustor by nonlinear time series analysis to evaluate permutation entropy, fractal dimensions, and short-term predictability. The dynamic behavior in combustion instability near lean blowout exhibits a self-affine structure and is ascribed to fractional Brownian motion. It undergoes chaos by the onset of combustion oscillations with slow amplitude modulation. Our results indicate that nonlinear time series analysis is capable of characterizing complexities in combustion instability close to lean blowout.

  5. El Movimiento Estudiantil--from the Sixties to the Seventies

    Science.gov (United States)

    Martinez, Douglas R.

    1978-01-01

    It was a history which saw "blowouts" at East Los Angeles high schools in 1968 over the lack of Chicano faculty and Chicano Studies Programs and the emergence of student strikes to press for more educational programs for Hispanics. And a decade later, Hispanic students are peacefully, but by no means passively, pressing their petition…

  6. 30 CFR 250.444 - What are the choke manifold requirements?

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What are the choke manifold requirements? 250.444 Section 250.444 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE... Blowout Preventer (bop) System Requirements § 250.444 What are the choke manifold requirements? (a)...

  7. Small Scale Burner Review

    Science.gov (United States)

    2009-07-01

    3 2.3 Flame Ignition, Flame Stability, and Extinction Characteristics in Microchannel ........3...3. Approaches to Achieve Combustion in Microscale 4 3.1 Heat Recirculation in Microchannels and Swiss Roll Combustors...19, 20). Blowout occurs when a flame gets swept out of the reactor at low residence time (i.e., high flow rates). In radical quenching, the free

  8. 30 CFR 57.2 - Definitions.

    Science.gov (United States)

    2010-07-01

    ... material, or gases from an explosion may cause injury to persons. In determining the blast area, the... areas at, in, or around a mine or plant where men work or travel. American Table of Distances means the... blasting circuit. Blowout means a sudden, violent, release of gas or liquid due to the reservoir...

  9. 78 FR 72688 - Information Collection Activities: Application for Permit To Drill; Proposed Collection; Comment...

    Science.gov (United States)

    2013-12-03

    ..., casing setting depths, drilling fluid (mud) programs, cementing programs and blowout preventer (BOP...; 134E1700D2 EEEE500000 ET1SF0000.DAQ000] Information Collection Activities: Application for Permit To Drill... data and information that is submitted with an Application for Permit to Drill (APD), a Revised...

  10. 30 CFR 250.445 - What are the requirements for kelly valves, inside BOPs, and drill-string safety valves?

    Science.gov (United States)

    2010-07-01

    ...). You must be able to strip the lower kelly valve through the BOP stack; (c) If you drill with a mud..., inside BOPs, and drill-string safety valves? 250.445 Section 250.445 Mineral Resources MINERALS... CONTINENTAL SHELF Oil and Gas Drilling Operations Blowout Preventer (bop) System Requirements § 250.445...

  11. A two-fluid model for vertical flow applied to CO2 injection wells

    DEFF Research Database (Denmark)

    Linga, Gaute; Lund, Halvor

    2016-01-01

    the well, including tubing, packer fluid, casing, cement or drilling mud, and rock formation. This enables prediction of the temperature in the well fluid and in each layer of the well. The model is applied to sudden shut-in and blowout cases of a CO2 injection well, where we employ the highly accurate...

  12. Modeling contractor and company employee behavior in high hazard operation

    NARCIS (Netherlands)

    Lin, P.H.; Hanea, D.; Ale, B.J.M.

    2013-01-01

    The recent blow-out and subsequent environmental disaster in the Gulf of Mexico have highlighted a number of serious problems in scientific thinking about safety. Risk models have generally concentrated on technical failures, which are easier to model and for which there are more concrete data. Howe

  13. Diplopia and orbital wall fractures

    NARCIS (Netherlands)

    Boffano, P.; Roccia, F.; Gallesio, C.; Karagozoglu, K.H.; Forouzanfar, T.

    2014-01-01

    Diplopia is a symptom that is frequently associated with orbital wall fractures. The aim of this article was to present the incidence and patterns of diplopia after orbital wall blow-out fractures in 2 European centers, Turin and Amsterdam, and to identify any correlation between this symptom and su

  14. The Proceedings of the Conference on Assessment of Ecological Impacts of Oil Spills Held 14-17 Jun 1978, Keystone, Colorado.

    Science.gov (United States)

    1978-01-01

    contributor to the Ekofisk blowout raise intriguing questions concerning the means and ethics of inducing behavioral changes in a guest for zero—error...stirring for 48 hr at 20 C in a closed conta iner . Toxicity Exper irnents A- simple embryological bioassay , using the oo on Pacific subtidal starfish

  15. 75 FR 13568 - MMS Information Collection Activity: 1010-0142, Decommissioning Activities, Extension of a...

    Science.gov (United States)

    2010-03-22

    ..., Decommissioning Activities. OMB Control Number: 1010-0142. Abstract: The Outer Continental Shelf (OCS) Lands Act... prevent or minimize the likelihood of blowouts, loss of well control, fires, spillages, physical... cleared of obstructions; remove casing stub or mud line suspension equipment and subsea...

  16. High-voltage safety fuses for the transition-radiation tracking detector in the ATLAS experiment

    NARCIS (Netherlands)

    Voronov, SA; Voronov, YA; Onishchenko, EM; Simakov, AB; Sosnovtsev, VV; Suchkov, SI; Sugrobova, TA

    2004-01-01

    A safety fuse has been designed for the electrical protection of gas-filled detectors in the ATLAS experiment at CERN (Geneva, Switzerland). The fuse is a polished lithium niobate plate with a titanium strip of 91-kOmega resistance deposited by the photolithographic technique. The forced blow-out ti

  17. Instability of a witness bunch in a plasma bubble

    Energy Technology Data Exchange (ETDEWEB)

    Burov, A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Lebedev, V. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Nagaitsev, S. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2016-02-16

    The stability of a trailing witness bunch, accelerated by a plasma wake accelerator (PWA) in a blow-out regime, is discussed. The instability growth rate as well as the energy spread, required for BNS damping, are obtained. A relationship between the PWA power efficiency and the BNS energy spread is derived.

  18. Rapid Growth of China Petroleum Machinery Manufacturing (continued)

    Institute of Scientific and Technical Information of China (English)

    Huang Zhiqian; Sun Zuchen; Wang Keyu

    1996-01-01

    @@ Technology for petroleum machinery design and manufacturing upgraded remarkably The basic research on rock bit. drilling pump. pump valve, piston, flooding pumps, derrick, shale shaker.hydraulic blowout preventer, torque converter, pumping unit. sucker rod. submersible pump. fracturing pump centrifugal pump. pneumatic parts, geophone and acquisition station has reached the advanced international level.

  19. A Golden Week to Spend

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The weeklong National Day holiday sees a record spending blowout, displaying the huge potential of the Chinese consumption market Rong Xinchun, 38, works at a research institute in Beijing. Recently married,he chose to have his wedding during the National Day holiday because both his family and guests had enough time to enjoy the festivities.

  20. A Puzzled DME Industry In China

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Over the recent years,the DME industry in China has gained higher speed,something like a blowout.However,it needs time to foster the market and there are some problems with the industry itself. These were among the topics at the Third International Conference on DME & Fifth Asian DME Conference held recently in Shanghai.

  1. Deep impact : destruction and sinking of Deepwater Horizon a blow to offshore industry

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2010-06-15

    In the weeks following the blowout in British Petroleum's (BP) Macondo well in the Gulf of Mexico on April 20, 2010, the implications for the industry spread quickly, impacting operations around the world. When the Deepwater Horizon exploded, killing 11 crew members, the immediate impact of the blowout resulted in at least 5,000 barrels per day of oil leaking out of the wellbore. This article discussed the impacts of the oil blowout from the well and the response from BP, rig owner Transocean Ltd., and Haliburton. As of mid-May, 2010, several attempts to plug the well were unsuccessful. Solutions that attempted to block the well from leaking were presented, including several low-tech solutions to attack the two main sources of oil which were the failed blowout preventer and the crumpled up riser resting on the sea floor. The article noted that as a last solution the well could be intersected with a relief well that could block the flow at depth. This option could take two or three months to reach the required depth. The article then discussed the costs of the oil spill to BP, fisheries, the tourism industry, and other hard-hit sectors. It was concluded that similar to the spill caused by the Exxon Valdez in Alaska 21 years ago, the Gulf disaster will affect the image of the industry for years to come. 5 figs.

  2. How toxic is oil? Investigating specific receptor-mediated toxic effects of crude and refined oils

    NARCIS (Netherlands)

    Vrabie, C.M.

    2011-01-01

    Crude oils and refined oil products are major pollutants of the environment. Large oil spills, such as the recent blowout of the Deepwater Horizon in the Gulf of Mexico, raise concerns about the long term health effects of petroleum hydrocarbon exposure on wildlife and humans. In the environmental r

  3. The influence of dust grain porosity on the analysis of debris disc observations

    Science.gov (United States)

    Brunngräber, Robert; Wolf, Sebastian; Kirchschlager, Florian; Ertel, Steve

    2017-02-01

    Debris discs are often modelled assuming compact dust grains, but more and more evidence for the presence of porous grains is found. We aim at quantifying the systematic errors introduced when modelling debris discs composed of porous dust with a disc model assuming spherical, compact grains. We calculate the optical dust properties derived via the fast, but simple effective medium theory. The theoretical lower boundary of the size distribution - the so-called `blowout size' - is compared in the cases of compact and porous grains. Finally, we simulate observations of hypothetical debris discs with different porosities and feed them into a fitting procedure using only compact grains. The deviations of the results for compact grains from the original model based on porous grains are analysed. We find that the blowout size increases with increasing grain porosity up to a factor of 2. An analytical approximation function for the blowout size as a function of porosity and stellar luminosity is derived. The analysis of the geometrical disc set-up, when constrained by radial profiles, is barely affected by the porosity. However, the determined minimum grain size and the slope of the grain size distribution derived using compact grains are significantly overestimated. Thus, the unexpectedly high ratio of minimum grain size to blowout size found by previous studies using compact grains can be partially described by dust grain porosity, although the effect is not strong enough to completely explain the trend.

  4. First field example of remediation of unwanted migration from a natural CO2 reservoir: The Bečej Field, Serbia

    NARCIS (Netherlands)

    Karas, D.; Demić, I.; Kultysheva, K.; Antropov, A.; Blagojević, M.; Neele, F.; Pluymaekers, M.; Orlić, B.

    2016-01-01

    The Bečej field, discovered in 1951 by the Petroleum Industry of Serbia (NIS), is one of the largest natural CO2 fields in Europe. Uncontrolled migration of CO2 out of the main reservoir, leading to subsurface seepage and surface leakage, was caused by the Bč-5 well blowout in 1968. Remediation meas

  5. Wellbore enlargement investigation: Potential analogs to the Waste Isolation Pilot Plant during inadvertent intrusion of the repository

    Energy Technology Data Exchange (ETDEWEB)

    Boak, D.M.; Dotson, L.; Aguilar, R. [and others

    1997-01-01

    This study involved the evaluation and documentation of cases in which petroleum wellbores were enlarged beyond the nominal hole diameter as a consequence of erosion during exploratory drilling, particularly as a function of gas flow into the wellbore during blowout conditions. A primary objective was to identify analogs to potential wellbore enlargement at the Waste Isolation Pilot Plant (WIPP) during inadvertent human intrusion. Secondary objectives were to identify drilling scenarios associated with enlargement, determine the physical extent of enlargement, and establish the physical properties of the formation in which the enlargement occurred. No analogs of sufficient quality to establish quantitative limits on wellbore enlargement at the WIPP disposal system were identified. However, some information was obtained regarding the frequency of petroleum well blowouts and the likelihood that such blowouts would bridge downhole, self-limiting the surface release of disposal-system material. Further work would be necessary, however, to determine the conditions under which bridging could occur and the extent to which the bridging might be applicable to WIPP. In addition, data on casing sizes of petroleum boreholes in the WIPP vicinity support the use of a 12-{1/4} inch borehole size in WIPP performance assessment calculations. Finally, although data are limited, there was no evidence of significant wellbore enlargement in any of three blowouts that occur-red in wellbores in the Delaware Basin (South Culebra Bluff Unit No. 1, Energy Research and Development Administration (ERDA) 6, and WIPP 12).

  6. Magnetic Untwisting in Most Solar X-Ray Jets

    Science.gov (United States)

    Moore, Ronald; Sterling, Alphonse; Falconer, David; Robe, Dominic

    2013-01-01

    From 54 X-ray jets observed in the polar coronal holes by Hinode's X-Ray Telescope (XRT) during coverage in movies from Solar Dynamic Observatory's Atmospheric Imaging Assembly (AIA) taken in its He II 304 Å band at a cadence of 12 s, we have established a basic characteristic of solar X-ray jets: untwisting motion in the spire. In this presentation, we show the progression of few of these X-ray jets in XRT images and track their untwisting in AIA He II images. From their structure displayed in their XRT movies, 19 jets were evidently standard jets made by interchange reconnection of the magnetic-arcade base with ambient open field, 32 were evidently blowout jets made by blowout eruption of the base arcade, and 3 were of ambiguous form. As was anticipated from the >10,000 km span of the base arcade in most polar X-ray jets and from the disparity of standard jets and blowout jets in their magnetic production, few of the standard X-ray jets (3 of 19) but nearly all of the blowout X-ray jets (29 of 32) carried enough cool (T is approximately 105 K) plasma to be seen in their He II movies. In the 32 X-ray jets that showed a cool component, the He II movies show 10-100 km/s untwisting motions about the axis of the spire in all 3 standard jets and in 26 of the 29 blowout jets. Evidently, the open magnetic field in nearly all blowout X-ray jets and probably in most standard X-ray jets carries transient twist. This twist apparently relaxes by propagating out along the open field as a torsional wave. High-resolution spectrograms and Dopplergrams have shown that most Type-II spicules have torsional motions of 10-30 km/s. Our observation of similar torsional motion in X-ray jets strengthens the case for Type-II spicules being made in the same way as X-ray jets, by blowout eruption of a twisted magnetic arcade in the spicule base and/or by interchange reconnection of the twisted base arcade with the ambient open field. This work was funded by NASA's Heliophysics Division

  7. Optimal stretching of fluid for enhancing reaction growth

    Science.gov (United States)

    Nevins, Thomas; Kelley, Douglas

    2016-11-01

    When a biological or chemical scalar grows in flowing fluid, the resulting reacted region is dependent on both the details of the flow, and the reaction kinetics. We simultaneously film reaction state and flow in a laboratory model of reactive mixing in order to examine reactive mixing in physical, time-dependent flows. Using the excitable Belousov-Zhabotinsky (BZ) reaction, we find an optimal stretching range in which the flow enhances reaction, but larger stretching causes reaction blowout. We observe the transition from flow mostly helping to mostly blowout is not associated with the transition to turbulence, and that stretching fields (closely related to finite-time Lyapunov exponents) inside the optimal range appear to have a large effect on reaction growth rate locally. We also present estimates of the optimal stretching for BZ, and hypothesize that it is a feature exclusive to excitable reactions.

  8. Contributions of La Niña and El Niño to middle Holocene drought and late Holocene moisture in the American Southwest

    Science.gov (United States)

    Menking, Kirsten M.; Anderson, Roger Y.

    2003-11-01

    Eolian landforms in Estancia basin, central New Mexico, record two episodes of extreme drought and low groundwater levels during the middle Holocene (7000 5400 14C yr B.P.), followed by a rise in the water table through the late Holocene. Blowouts and associated lunettes formed when water levels fell below the desiccated floor of pluvial Lake Estancia, allowing widespread deflation. Elevation of the water table in the basin is regulated by a balance between evaporation from playas that occupy the blowouts and recharge of aquifers in the adjacent Manzano Mountains. Isotopic analyses of modern precipitation and groundwater reveal that recharge originates primarily as winter moisture, which is amplified during El Niños and diminished during La Niñas. Thus, changes in the elevation of a reconstructed Holocene water table may reflect systematic changes in El Niño Southern Oscillation (ENSO) circulation.

  9. Gas production and storage - gas transport and supply. Colloquium 7th conference proceedings; Gasfoerderung und Gasspeicherung - Gastransport und Gasversorgung. Kolloquium 7. Tagungsband

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, S. [ed.] [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Bohrtechnik und Fluidbergbau; Koeckritz, V. [comp.

    1999-07-01

    The colloquium papers discuss trends in gas supply engineering, automtion of gas storages, liberalisation of the gas market, and gas management systems in integrated supply systems. Rock-mechanical problems of natural gas storage caverns are mentioned. Further subjects are gas extraction rom coal seams, power generation from gas in fuel cells, a model for blowout calculation of real gases, and vortex tubes in gas pressure reduction systems. 19 contributions have been recorded separately in this database. [German] Die einzelnen Beitraege des Kolloquiums befassen sich mit den Entwicklungen in der Gasversorgungstechnik, mit der Automatisierung von Gasspeichern, mit der Liberalisierung des Gasmarktes sowie mit Gasmanagementsystemen in Verbundnetzen. Neben der Gasspeicherung in Porenspeichern und Salzkavernen, deren Sicherheit und der Soleversenkung, sind Betraege zu gebirgsmechanischen Problemen in Erdgasspeicherkavernen enthalten. Weitere Themen sind die Gasfoerderung aus Steinkohlefloezen, die Energieerzeugung aus Gas in Brennstoffzellen, ein Modell zur Blowout-Berechnung realer Gase sowie Wirbelrohre in Anlagen zur Gasdruckminderung. Fuer die Datenbank Energy wurden 19 Beitraege separat aufgenommen.

  10. The value of offshore field experiments in oil spill technology development for Norwegian waters.

    Science.gov (United States)

    Faksness, Liv-Guri; Brandvik, Per Johan; Daling, Per S; Singsaas, Ivar; Sørstrøm, Stein Erik

    2016-10-15

    The blowout on the Ekofisk field in the North Sea in 1977 initiated R&D efforts in Norway focusing on improving oil spill contingency in general and more specifically on weathering processes and modeling drift and spreading of oil spills. Since 1978, approximately 40 experimental oil spills have been performed under controlled conditions in open and ice covered waters in Norway. The importance of these experimental oil spills for understanding oil spill behavior, development of oil spill and response models, and response technologies are discussed here. The large progress within oil spill R&D in Norway since the Ekofisk blowout has been possible through a combination of laboratory testing, basin studies, and experimental oil spills. However, it is the authors' recommendation that experimental oil spills still play an important role as a final validation for the extensive R&D presently going on in Norway, e.g. deep-water releases of oil and gas.

  11. Aviation fuel property effects on altitude relight

    Science.gov (United States)

    Venkataramani, K.

    1987-01-01

    The major objective of this experimental program was to investigate the effects of fuel property variation on altitude relight characteristics. Four fuels with widely varying volatility properties (JP-4, Jet A, a blend of Jet A and 2040 Solvent, and Diesel 2) were tested in a five-swirl-cup-sector combustor at inlet temperatures and flows representative of windmilling conditions of turbofan engines. The effects of fuel physical properties on atomization were eliminated by using four sets of pressure-atomizing nozzles designed to give the same spray Sauter mean diameter (50 + or - 10 micron) for each fuel at the same design fuel flow. A second series of tests was run with a set of air-blast nozzles. With comparable atomization levels, fuel volatility assumes only a secondary role for first-swirl-cup lightoff and complete blowout. Full propagation first-cup blowout were independent of fuel volatility and depended only on the combustor operating conditions.

  12. Transverse self-modulation of ultra-relativistic lepton beams in the plasma wakefield accelerator

    CERN Document Server

    Vieira, J; Mori, W B; Silva, L O; Muggli, P

    2015-01-01

    The transverse self-modulation of ultra-relativistic, long lepton bunches in high-density plasmas is explored through full-scale particle-in-cell simulations. We demonstrate that long SLAC-type electron and positron bunches can become strongly self-modulated over centimeter distances, leading to wake excitation in the blowout regime with accelerating fields in excess of 20 GV/m. We show that particles energy variations exceeding 10 GeV can occur in meter-long plasmas. We find that the self-modulation of positively and negatively charged bunches differ when the blowout is reached. Seeding the self-modulation instability suppresses the competing hosing instability. This work reveals that a proof-of-principle experiment to test the physics of bunch self-modulation can be performed with available lepton bunches and with existing experimental apparatus and diagnostics.

  13. Hydrogen in natural gases. [In natural gas, in methane in coal deposits and in petroleum deposits

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, A.K.

    1983-01-01

    Extensive factual material regarding hydrogen in the most diverse gases is generalized. Especial attention is focused on hydrogen contained in gases of carboniferous basins. Results are presented of studies of hydrogen content of coal gases of the Donets and L'vov-Volynskiy carboniferous basins, and also in gases of the fields of the Dnieper-Donets Basin. Differences were established in gases of the petroleum and coal series according to their content of hydrogen, and also coal beds and surrounding rocks which are dangerous and not dangerous for sudden blowout. Questions are examined of the genesis of hydrogen. Results are presented of experimental studies to reveal the secondary hydrogen in gases. It is indicated that hydrogen can serve as an important criterion in prospecting for a number of minerals and an indicator in predicting sudden blowouts of coal, rock and gas in mines.

  14. RECURRENT SOLAR JETS INDUCED BY A SATELLITE SPOT AND MOVING MAGNETIC FEATURES

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jie; Su, Jiangtao; Yin, Zhiqiang; Priya, T. G.; Zhang, Hongqi; Xu, Haiqing; Yu, Sijie [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Liu, Jihong, E-mail: chenjie@bao.ac.cn [Shi Jiazhuang University, Shi Jiazhuang, 050035 (China)

    2015-12-10

    Recurrent and homologous jets were observed to the west edge of active region NOAA 11513 at the boundary of a coronal hole. We find two kinds of cancellations between opposite polarity magnetic fluxes, inducing the generation of recurrent jets. First, a satellite spot continuously collides with a pre-existing opposite polarity magnetic field and causes recurrent solar jets. Second, moving magnetic features, which emerge near the sunspot penumbra, pass through the ambient plasma and eventually collide with the opposite polarity magnetic field. Among these recurrent jets, a blowout jet that occurred around 21:10 UT is investigated. The rotation of the pre-existing magnetic field and the shear motion of the satellite spot accumulate magnetic energy, which creates the possibility for the jet to experience blowout right from the standard.

  15. A case of isolated abducens nerve paralysis in maxillofacial trauma

    Science.gov (United States)

    Keskin, Elif Seda; Keskin, Ekrem; Atik, Bekir; Koçer, Abdülkadir

    2015-01-01

    Nervus abducens is a pure motor nerve located in the pons. It retracts the eyeball laterally by stimulating rectus lateralis muscle. In case of their paralysis, diplopia and restriction in the eye movements while looking sideways, are seen. Since the same signs are seen due to the muscle entrapment in blowout fractures, its differential diagnosis has importance in terms of the treatment protocol and avoiding unnecessary operations. In this article, we present a 22-year-old male patient who was referred to our department due to the prediagnosis of blowout fracture following maxillofacial trauma. However, he was diagnosed with abducens nerve paralysis after the consultations and analysis and his restriction of movement was resolved via systemic steroid treatment instead of unnecessary operation. PMID:26981484

  16. Maritime Security: Progress Made, but Further Actions Needed to Secure the Maritime Energy Supply

    Science.gov (United States)

    2011-08-24

    technologies to control and contain blowouts occurring in subsea environments. We are conducting this work at the request of the Ranking Member of the House...currently valid OMB control number. 1. REPORT DATE 24 AUG 2011 2. REPORT TYPE 3. DATES COVERED 00-00-2011 to 00-00-2011 4. TITLE AND SUBTITLE...risk model and relevant laws, regulations, policies, and procedures; and interviewed Coast Guard officials. What GAO Recommends GAO is recommending

  17. Geopressures

    Energy Technology Data Exchange (ETDEWEB)

    Stuart, Charles A.

    1970-01-30

    Geopressures play a dominant role in the oil and gas industry. These pore-fluid pressures have been the source of such well problems as blowouts, stuck pipe, no drilling progress, lost circulation, saltwater flows, etc. At one time, offshore drilling did not appear profitable because of high drilling costs. Deep target objectives were rarely attained. The concept of impenetrable rocks was accepted as fact in the Gulf Coast.

  18. QRA techniques on dynamic positioning systems during drilling operations in the Arctic: With emphasis on the dynamic positioning operator

    OpenAIRE

    2015-01-01

    With the Norwegian government moving the ice edge farther north than ever before, opening for new areas for petroleum exploration, it will need research on how these areas can affect oil and gas operations. A sensitive environment along with the harsh Arctic climate and remote distances means that severe accidents, like blowouts, will have serious impacts and make cleanup and rescue actions to challenging operations. Additionally, humans working under these conditions are prone to be affected...

  19. A Crashworthiness Analysis with Emphasis on the Fire Hazard: U.S. and Selected Foreign Turbine Aircraft Accidents, 1964-1974

    Science.gov (United States)

    1976-07-01

    concentration of hydrogen fluoride resulting from the pyrolysis of Halon 1301 suppressing agent was measured in these tests to establish whether human...1965 Summary, Pg. 11 21. 6/14/65, DC-8, , Santiago, Chile Left main landing gear brakes were locked on touchdown causing tire blowouts and a small fire...Damage was confined to the tires , wheels, and related components of the left main gear. Passengers were evacuated via two galley doors and main

  20. Inductive shearing of drilling pipe

    Energy Technology Data Exchange (ETDEWEB)

    Ludtka, Gerard M.; Wilgen, John; Kisner, Roger; Mcintyre, Timothy

    2016-04-19

    Induction shearing may be used to cut a drillpipe at an undersea well. Electromagnetic rings may be built into a blow-out preventer (BOP) at the seafloor. The electromagnetic rings create a magnetic field through the drillpipe and may transfer sufficient energy to change the state of the metal drillpipe to shear the drillpipe. After shearing the drillpipe, the drillpipe may be sealed to prevent further leakage of well contents.

  1. High Impact Technology Compact Combustion (HITCC) Compact Core Technologies

    Science.gov (United States)

    2016-01-01

    correlation as the chemical “timescale.” The resulting correlation equation is Eq 22. Including laminar flame speed improved the R-squared value from...including: 1) ultra-compact combustors, 2) inter-turbine burner concepts, 3) bluff-body stabilized turbulent flames, 4) well-stirred reactors for... chemical kinetics, and 5) detonation-stabilized turbulent flames. Lean blowout data was collected on propane and jet fuel bluff-body stabilized flames

  2. Behavior of cooling jet in the lateral injection in film cooling. 1st Report. ; Time-averaged velocity and temperature field. Span hoko ni fukidasu makureikyaku ni okeru reikyaku kuki no kyodo. 1. ; Jikan heikin sokudoba to ondoba

    Energy Technology Data Exchange (ETDEWEB)

    Uchiyama, A. (Mitsubishi Heavy Industries, Ltd., Tokyo (Japan)); Yamamoto, M. (Toyota Motor Corp., Aichi (Japan)); Shizawa, T.; Honami, S. (Science University of Tokyo, Tokyo (Japan). Faculty of Engineering)

    1994-02-25

    In order to improve the gas turbine blade film cooling technology, this paper elucidates flow field and temperature field of secondary air blown out into a span direction; derives the temperature distribution on the wall face; and describes cooling air behavior in film cooling. The wall face temperature distribution measured with a temperature measuring system using liquid crystal has shown relatively good correspondence with the temperature distribution in the vicinity of the wall face as measured by a two-wire probe. Film cooling by blowing air into the span direction has shown good attachment of the secondary air onto the wall face in the secondary air blowing direction. However, in the opposite direction to the air blowing direction, air has attached to the wall face only poorly because of vortex movements of the primary air due to being dragged in. The secondary air has departed from the wall face as the blow-out ratio has been increased, resulting in drop in the cooling efficiency. A 'Z' direction position that the temperature of the secondary air shows a maximum value differs from a 'Z' direction position having a peak in the wall face cooling efficiency, the difference having become more noticeable with increasing blow-out ratio. A region with lower cooling efficiency due to rolling-in of the primary air exists near the blow-out hole, where rolling-in of the primary air is recognized prominently as the blow-out ratio has been increased. 8 refs., 6 figs.

  3. Pelagic tar off Georgia and Florida in relation to physical processes

    Energy Technology Data Exchange (ETDEWEB)

    Cordes, C.; Atkinson, L.; Lee, R.; Blanton, J.

    1980-11-01

    It was hypothesized, following the Ixtoc oil rig blowout in Campeche Bay in August 1979, that resultant tarballs should eventually appear in the Gulf stream off Georgia and that little would reach nearshore areas. Surface tows to collect floating tar were conducted off the coasts of Georgia and Florida to test this hypothesis. No tar was found within 40 km of shore. All samples more than 40 km from shore contained some tar.

  4. Analysis on the nitrogen drilling accident of Well Qionglai 1 (I: Major inducement events of the accident

    Directory of Open Access Journals (Sweden)

    Yingfeng Meng

    2015-12-01

    Full Text Available Nitrogen drilling in poor tight gas sandstone should be safe because of very low gas production. But a serious accident of fire blowout occurred during nitrogen drilling of Well Qionglai 1. This is the first nitrogen drilling accident in China, which was beyond people's knowledge about the safety of nitrogen drilling and brought negative effects on the development of gas drilling technology still in start-up phase and resulted in dramatic reduction in application of gas drilling. In order to form a correct understanding, the accident was systematically analyzed, the major events resulting in this accident were inferred. It is discovered for the first time that violent ejection of rock clasts and natural gas occurred due to the sudden burst of downhole rock when the fractured tight gas zone was penetrated during nitrogen drilling, which has been named as “rock burst and blowout by gas bomb”, short for “rock burst”. Then all the induced events related to the rock burst are as following: upthrust force on drilling string from rock burst, bridging-off formed and destructed repeatedly at bit and centralizer, and so on. However, the most direct important event of the accident turns out to be the blockage in the blooie pipe from rock burst clasts and the resulted high pressure at the wellhead. The high pressure at the wellhead causes the blooie pipe to crack and trigged blowout and deflagration of natural gas, which is the direct presentation of the accident.

  5. Effect of hypercholesterolemia on experimental colonic anastomotic wound healing in rats

    Institute of Scientific and Technical Information of China (English)

    Meral (S)en; A Ziya Anadol; Mehmet O(g)uz

    2006-01-01

    AIM: To evaluate the mechanical and biochemicalparameters of colonic anastomotic healing inhypercholesterolemic rats.METHODS: Sixty rats were divided into two groups of 30each according to their dietary regimens. The test groupwas fed with a high cholesterol-containing diet for twomonths while the control group had standard diet. Thesetwo groups were further divided into three subgroupsconsisting of ten rats each. After hypercholesterolemiawas established, left colon resection and anastomosiswere performed in both groups and samples from liverand abdominal aorta were taken to evaluate the systemiceffects of hypercholesterolemia. Anastomotic woundhealing, blow-out pressures and tissue hydroxyprolinelevels were evaluated.RESULTS: The test group had a significant weight gainin two months. Microscopic examination of the abdominalaorta revealed no atherosclerotic change in none of thegroups, but liver tissue specimens showed significantsteatosis in the testgroup. Tissue hydroxyproline levelsand anastomotic blow-out pressures were significantlylower in the test group than in the controls.CONCLUSION: Hypercholesterolemia not only increaseshydroxyproline levels and blow-out pressures but alsoworsens anastomotic wound healing.

  6. 深水防喷器组及控制系统实验教学平台研制%Development of experimental teaching platform of subsea blow out preventer stacks and control systems

    Institute of Scientific and Technical Information of China (English)

    蔡宝平; 刘永红; 艾白布·阿不力米提; 于示林; 王龙庭; 董欣

    2014-01-01

    针对深水防喷器组系统实验教学的需要,研制了一套深水防喷器组及控制系统实验教学平台。该教学平台由深水防喷器组模拟样机、深水防喷器液控系统模拟样机和深水防喷器电控系统模拟样机等三部分组成。采用该平台进行综合实验,学生可掌握深水闸板防喷器的工作原理和结构组成、双冗余液控系统的工作原理和液压流程、双两模冗余电控系统的工作原理及实现方式,加深学生对海洋石油装备高可靠性控制方式的认识和理解,有效提高了学生机电液结合的动手与工程应用能力。%Aiming-at-the-need-of-the-experimental-teaching-of-subsea-blowout-preventer-stacks-system-,a-set-of-experimental-teaching-platform-of-subsea-blowout-preventer-stacks-and-control-systems-is-developed-.The-teaching-platform-consists-of-the-subsea-blowout-preventer-stacks-simulation-prototype-,-subsea-blowout-preventer-hydraulic-control-system-simulation-prototype-and-subsea-blowout-preventer-electric-control-system-simulation-prototype-.Using-the-platform-for-comprehensive-experiments-,students-can-grasp-the-working-principle-and-structure-of-the-subsea-blowout-preventer-,the-working-principle-and-hydraulic-pressure-process-of-the-dual-redundant-hydraulic-control-system-,the-working-principle-and-implementation-approach-of-double-dual-modular-electric-control-system-.The-students-can-deepen-the-understanding-of-ocean-oil-equipment’s-reliability-control-mode-and-improve-the-engineering-application-and-operational-ability-of-mechanical-electrical-hydraulic-integration-effectively-.

  7. Filament Eruptions, Jets, and Space Weather

    Science.gov (United States)

    Moore, Ronald; Sterling, Alphonse; Robe, Nick; Falconer, David; Cirtain, Jonathan

    2013-01-01

    Previously, from chromospheric H alpha and coronal X-ray movies of the Sun's polar coronal holes, it was found that nearly all coronal jets (greater than 90%) are one or the other of two roughly equally common different kinds, different in how they erupt: standard jets and blowout jets (Yamauchi et al 2004, Apl, 605, 5ll: Moore et all 2010, Apj, 720, 757). Here, from inspection of SDO/AIA He II 304 A movies of 54 polar x-ray jets observed in Hinode/XRT movies, we report, as Moore et al (2010) anticipated, that (1) most standard x-ray jets (greater than 80%) show no ejected plasma that is cool enough (T is less than or approximately 10(exp 5K) to be seen in the He II 304 A movies; (2) nearly all blownout X-ray jets (greater than 90%) show obvious ejection of such cool plasma; (3) whereas when cool plasma is ejected in standard X-ray jets, it shows no lateral expansion, the cool plasma ejected in blowout X-ray jets shows strong lateral expansion; and (4) in many blowout X-ray jets, the cool plasma ejection displays the erupting-magnetic-rope form of clasic filament eruptions and is thereby seen to be a miniature filament eruption. The XRT movies also showed most blowout X-ray jets to be larger and brighter, and hence to apparently have more energy, than most standard X-ray jets. These observations (1) confirm the dichotomy of coronal jets, (2) agree with the Shibata model for standard jets, and (3) support the conclusion of Moore et al (2010) that in blowout jets the magnetic-arch base of the jet erupts in the manner of the much larger magnetic arcades in which the core field, the field rooted along the arcade's polarity inversion line, is sheared and twisted (sigmoid), often carries a cool-plasma filament, and erupts to blowout the arcade, producing a CME. From Hinode/SOT Ca II movies of the polar limb, Sterling et al (2010, ApJ, 714, L1) found that chromospheric Type-II spicules show a dichotomy of eruption dynamics similar to that found here for the cool

  8. Upper Eyelid Retraction After Periorbital Trauma

    OpenAIRE

    2008-01-01

    We report four unusual cases of upper eyelid retraction following periorbital trauma. Four previously healthy patients were evaluated for unilateral upper eyelid retraction following periorbital trauma. A 31-year-old man (Case 1) and a 24-year-old man (Case 2) presented with left upper eyelid retraction which developed after blow-out fractures, a 44-year-old woman (Case 3) presented with left upper eyelid retraction secondary to a periorbital contusion that occurred one week prior, and a 56-y...

  9. Hose Instability and Wake Generation By An Intense Electron Beam in a Self-Ionized Gas

    Energy Technology Data Exchange (ETDEWEB)

    Deng, S.; Barnes, C.D.; Clayton, C.E.; O' Connell, C.; Decker, F.J.; Fonseca, R.A.; Huang, C.; Hogan, M.J.; Iverson, R.; Johnson, D.K.; Joshi, C.; Katsouleas, T.; Krejcik,; Lu, W.; Mori, W.B.; Muggli, P.; Oz, E.; Tsung, F.; Walz, D.; Zhou, M.; /Southern California U. /UCLA /SLAC

    2006-04-12

    The propagation of an intense relativistic electron beam through a gas that is self-ionized by the beam's space charge and wakefields is examined analytically and with 3D particle-in-cell simulations. Instability arises from the coupling between a beam and the offset plasma channel it creates when it is perturbed. The traditional electron hose instability in a preformed plasma is replaced with this slower growth instability depending on the radius of the ionization channel compared to the electron blowout radius. A new regime for hose stable plasma wakefield acceleration is suggested.

  10. An Exploratory Study of Crises in Product Development

    DEFF Research Database (Denmark)

    Muenzberg, Christopher; Gericke, K.; Oehmen, Josef

    2016-01-01

    In April 2010, the Deepwater Horizon oil rig exploded in the Gulf of Mexico. The explosion killed 11workers. In order to stop the oil outflow, the workers attempted to activate the blowout preventer, which failed. As a consequence, more than 779 million litres of oil streamed into the Gulf...... of Mexico during the following 4 months, causing the biggest oil spill in history. Besides the enormous environmental destruction and the death of 11 men, the Deepwater Horizon crisis accrued a high image loss for the oilrig operator. The direct cost of the crisis summed up to 35.6 billion € [The Economist...

  11. Efficiency Versus Instability in Plasma Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Lebedev, Valeri [Fermilab; Burov, Alexey [Fermilab; Nagaitsev, Sergei [Fermilab

    2017-01-05

    Plasma wake-field acceleration in a strongly nonlinear (a.k.a. the blowout) regime is one of the main candidates for future high-energy colliders. For this case, we derive a universal efficiency-instability relation, between the power efficiency and the key instability parameter of the witness bunch. We also show that in order to stabilize the witness bunch in a regime with high power efficiency, the bunch needs to have high energy spread, which is not presently compatible with collider-quality beam properties. It is unclear how such limitations could be overcome for high-luminosity linear colliders.

  12. Penetrating injury of orbital roof and brain sparing the eye ball in a pediatric patient: A rare occurrence

    OpenAIRE

    Vikul Kumar; Atul Kumar Singh; Kulwant Singh Bhaikhel

    2016-01-01

    Blowout fractures are a common occurrence in traumatic brain injury patients. In pediatric age group, orbital floor fracture is a common occurrence. We report a case of 2-year-old male admitted to trauma center, with penetrating injury to the left eye by the clutch of motorbike which fell on the child. Noncontrast computed tomography scan revealed fracture of the roof of left orbit with left frontal contusion sparing the left eyeball. There was also the continuous leak of brain matter from th...

  13. Penetrating injury of orbital roof and brain sparing the eye ball in a pediatric patient: A rare occurrence.

    Science.gov (United States)

    Kumar, Vikul; Singh, Atul Kumar; Bhaikhel, Kulwant Singh

    2016-01-01

    Blowout fractures are a common occurrence in traumatic brain injury patients. In pediatric age group, orbital floor fracture is a common occurrence. We report a case of 2-year-old male admitted to trauma center, with penetrating injury to the left eye by the clutch of motorbike which fell on the child. Noncontrast computed tomography scan revealed fracture of the roof of left orbit with left frontal contusion sparing the left eyeball. There was also the continuous leak of brain matter from the left eye which suggested tear of dura mater. Urgent left frontal craniotomy was done with the evacuation of contusion, reconstruction of orbital roof, and duroplasty under general anesthesia.

  14. Measuring service life and evaluating the quality of solid tires

    Directory of Open Access Journals (Sweden)

    Charoenyut Dechwayukul

    2010-08-01

    Full Text Available The objective of this research is to propose procedures for measuring service life and evaluating the quality of locallymade and used solid tires in Thailand. The solid tires were stressed and rotated until blowout on a drum-like test apparatuswhich is designed, constructed by the authors and equipped with laboratory instrumentation. Solid tires from five differentmanufacturers were selected for testing. We measured service life, length of time to tire failure, at three different loadingamplitudes and three different speeds on the testing drum. The service life of all specimens was studied and compared todetermine the possibility of using service life to evaluate the quality of a solid tire.

  15. On the Deepwater Horizon drop size distributions

    Science.gov (United States)

    Ryerson, T. B.; Atlas, E. L.; Blake, D. R.; De Gouw, J. A.; Warneke, C.; Peischl, J.; Brock, C. A.; McKeen, S. A.

    2014-12-01

    Model simulations of the fate of gas and oil released following the Deepwater Horizon blowout in 2012 depend critically on the assumed drop size distributions. We use direct observations of surfacing time, surfacing location, and atmospheric chemical composition to infer an average drop size distribution for June 10, 2012, providing robust first-order constraints on parameterizations in models. We compare the inferred drop size distribution to published work on Deepwater Horizon and discuss the ability of this approach to determine the efficacy of subsurface dispersant injection.

  16. Characterization of degeneration process in thermo-acoustic combustion instability using dynamical systems theory

    Science.gov (United States)

    Hayashi, Kenta; Gotoda, Hiroshi; Okuno, Yuta; Tachibana, Shigeru; Tokyo University of Science Collaboration; Japan Aerospace Exploration Agency Collaboration

    2015-11-01

    We have experimentally investigated the degeneration process of combustion instability in a lean premixed gas-turbine model combustor on the basis of dynamical systems theory. Our previous study reported that with increasing the equivalence ratio, the dynamical behavior of combustion state close to lean blowout transits from stochastic fluctuations to periodic thermoacoustic combustion oscillations via low-dimensional chaotic oscillations. The further increase in the equivalence ratio gives rise to the quasi-periodic oscillations and the subsequent chaotic oscillations with small amplitudes. The route to chaotic oscillations is quantitatively shown by the use of nonlinear time series analysis involving the color recurrence plots, permutation entropy and local predictor.

  17. Amelioration de la procedure d'essai d'eclatement de joints d'etancheite a base de teflon

    Science.gov (United States)

    Benabdallah, Samir

    The objective of this work is to improve a HOt Blow-out Test procedure to determine the maximum operating temperature of Teflon-based gaskets. In parallel, an experimental fixture is developed to measure the thermal expansion coefficient of such material. This study aims to analyze the relaxation of PTFE gasketed joints due to creep at high temperature. The determination of the safe operating temperature limit of PTFE-based gaskets requires a good knowledge of its capacity to resist creep-relaxation due to temperature exposure in the short and long term. The aim of this work is to improve the HOBT standard procedure « Standard Test Method for Hot Blowout and Thermal Cycling Performance for Polytetrafluoroethylene (PTFE) Sheet or Sheet-Like Gaskets» which is under adoption by the ASTM F03 gasket committee. Based on a previous work, the introduction of a fixed number of cycles of heating and cooling in the HOBT test procedure has shown that the cumulative permanent deformation (ratcheting damage) which has impact on reduction of the gasket stress can be taken into account. The effect of holding temperature for a short period of time will be investigated. The modified HOBT rig allows measurement of the gasket compression during the test in order to accurately quantify the cumulative permanent deformation. Several types of PTFE-based gaskets will be tested in order to cover a wide range of gaskets to justify the generalization of the modified procedure. The different steps to achieve this project are listed below: 1. Improve the HOBT test rig by implementing a device to measure gasket compression and it variation with the thermal cycles. 2. Study the effects of the number of thermal cycling and the holding temperature on the gasket stress and the cumulative permanent deformation and the short term creep on the hot blowout characteristics of PTFE-based gaskets. 3. Development of a small fixture to measure the coefficient of thermal expansion of gasketing materials

  18. A rare case of 'blow-up' fracture of the orbit in a child

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Preena N.; Kenney, Ian J. [Royal Alexandra Hospital for Sick Children, Radiology Department, Brighton (United Kingdom)

    2009-08-15

    We present a case of blow-out fracture of the superomedial orbital wall in a 6-year-old boy. The initial plain radiograph showed an intact orbital margin and opacification of the ethmoid sinus. A fine-cut CT scan of the facial bones revealed a complex fracture of the medial orbital wall extending into the orbital roof, with migration of fracture fragments into the anterior cranial fossa. Suspicion for unusual orbital fractures is crucial when assessing a child for orbital trauma, especially when plain radiographs do not display the typical signs. (orig.)

  19. Analysis of ecological effects of geopressured-geothermal resource development. Geopressured-geothermal technical paper No. 4

    Energy Technology Data Exchange (ETDEWEB)

    1979-07-01

    The activities involved in geopressured-geothermal resource production are identified and their ecological impacts are discussed. The analysis separates those activites that are unique to geopressured-geothermal development from those that also occur in oil and gas and other resource developments. Of the unique activities, those with the greatest potential for serious ecological effect are: (1) accidental brine discharge as a result of a blowout during well drilling; (2) subsidence; (3) fault activation and enhanced seismicity; and (4) subsurface contamination of water, hydrocarbon, and mineral reservoirs. Available methods to predict and control these effects are discussed.

  20. Effect of forced ventilation on the dust concentration of partially ventilated mine worksites

    Energy Technology Data Exchange (ETDEWEB)

    Vekeny, H.

    1985-01-01

    The stone drifts and about two-thirds of the roadways in coal seams of the Mecsek Coal Mines, Hungary, are driven by forced ventilation which, in addition to its numerous merits, causes also air velocities significantly higher than optimum resulting in delivering dust particles and rock material produced by breaking of mineral and rock material into the atmosphere of worksites. This also increases the risk of silicosis of miners. A new device called a wind rose was developed and applied to the blow-out end of the ventilation duct leading to a better distribution of the discharged air stream in the drift.

  1. Investigation of a nozzle instability on an F100 engine equipped with a digital electronic engine control

    Science.gov (United States)

    Burcham, F. W., Jr.; Zeller, J. R.

    1984-01-01

    An instability in the nozzle of the F100 engine, equipped with a digital electronic engine control (DEEC), was observed during a flight evaluation on an F-15 aircraft. The instability occurred in the upper left hand corner (ULMC) of the flight envelope during augmentation. The instability was not predicted by stability analysis, closed-loop simulations of the the engine, or altitude testing of the engine. The instability caused stalls and augmentor blowouts. The nozzle instability and the altitude testing are described. Linear analysis and nonlinear digital simulation test results are presented. Software modifications on further flight test are discussed.

  2. High-voltage safety fuses for the transition-radiation tracking detector in the ATLAS experiment

    CERN Document Server

    Voronov, S A; Onishchenko, E M; Simakov, A B; Sosnovtsev, V V; Suchkov, S; Sugrobova, T A

    2004-01-01

    A safety fuse has been designed for the electrical protection of gas- filled detectors in the ATLAS experiment at CERN (Geneva, Switzerland). The fuse is a polished lithium niobate plate with a titanium strip of 91-kOmega resistance deposited by the photolithographic technique. The forced blowout time of the fuse is 10-50 ms; whereupon the leakage current through it is less than 1 nA at a 2-kV voltage. The resistance of the fuse case is greater than or equivalent equal' greater than 10**1**2 Omega. Its overall dimensions are 5.8 multiplied by 3.8 multiplied by 2 mm.

  3. Phenomenology of surface arcs on spacecraft dielectric materials

    Science.gov (United States)

    Balmain, K. G.; Gossland, M.; Reeves, R. D.; Kuller, W. G.

    1982-01-01

    For electron beam incidence on large specimens of Kapton thermal blanket material, surface arc discharges are shown to cause damage consisting of punchthrough holes which act as focal points for other types of damage, including subsurface tunnels, blowout holes and surface breakup. Under electron bombardment, dielectric sheet specimens separated by a gap are shown to discharge simultaneously. Teflon specimens which have been brushed or rubbed are shown to exhibit directional guidance of discharge arcs, and this phenomenon has been used to generate straight arcs whose velocities have been measured optically.

  4. On-Off Intermittency and Riddled Basins of Attraction in a Coupled Map System

    DEFF Research Database (Denmark)

    Laugesen, J.; Mosekilde, Erik; Maistrenko, Yu.L.

    1998-01-01

    The paper examines the appearance of on-off intermitting and riddled basins of attaction in a system of two coupled one-dimensional maps, each displaying type-III intermittency. The bifurcation curves for the transverse destabilization of low periodic orbits embedded in the synchronized chaotic...... state are obtained. Different types of riddling bifurcation are described, and we show how the existence of an absorbing area inside the basin of attraction can account for the distinction between local and global riddling as well as for the distinction between hysteric and non-hysteric blowout....

  5. Efficient numerical modelling of the emittance evolution of beams with finite energy spread in plasma wakefield accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Mehrling, T.J., E-mail: timon.mehrling@desy.de [Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg (Germany); Robson, R.E. [Centre for Quantum Dynamics, School of Natural Sciences, Griffith University, Brisbane (Australia); Erbe, J-H.; Osterhoff, J. [Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg (Germany)

    2016-09-01

    This paper introduces a semi-analytic numerical approach (SANA) for the rapid computation of the transverse emittance of beams with finite energy spread in plasma wakefield accelerators in the blowout regime. The SANA method is used to model the beam emittance evolution when injected into and extracted from realistic plasma profiles. Results are compared to particle-in-cell simulations, establishing the accuracy and efficiency of the procedure. In addition, it is demonstrated that the tapering of vacuum-to-plasma and plasma-to-vacuum transitions is a viable method for the mitigation of emittance growth of beams during their injection and extraction from and into plasma cells.

  6. What if Things Get Worse? Really Grand Challenges for Modeling and Simulation in a Risky and Complex World or Modeling and Simulation for the "Greater Good"?

    Science.gov (United States)

    Fifrey, Priscilla

    2010-01-01

    Today Modeling and Simulation-- ---as an important practice or industry or area of expertise ----- is at a complex crossroad - a sort of cyber-highway--where these complexities meet-technical, economic, environmental, geopolitical and cultural. They may converge or collide. Let's not kid ourselves. It is all too much for anyone person or organization Malcolm Gladwell said it. "We have constructed a world in which the potential for high tech catastrophe is embedded in the fabric of everyday life." We are surrounded by problems that scream at us from our television, Internet and social networks along with billboards and protest signs. We face not just high tech catastrophes but, also, landslides, earthquakes, tornados, floods and hurricanes and large-scale criminality. Evil, war, famine and pestilence have not gone away. It is all too much to think about. My friend, George Peabody, who taught me everything I know about power said that addressing such issues requires that we constantly build our network, information resources and the credibility and visibility of our work. That is how we will build the power of simulation so it can change the world --even maybe, save it. We need all the help we can get and give one another because our human early warning systems appear to be out of kilter. We seem to have trouble imagining how small failings can continue to lead to catastrophic disaster. Think about O-rings and blowout preventers. One is reminded of the old nursery rhyme, "For want of a nail, a shoe was lost! for want of a shoe the horse was lost! for want of a rider the battle was lost and so the kingdom fell." Although the investigation will take more time for real answers, it is worrisome that a rig worker reported to the BBC that-- weeks before the explosion of Deep Ocean Horizon. -he identified a leak in the oil rig's safety equipment -the Control Pod of the blowout preventer which has giant shears designed to cut and seal off the well's main pipe. With both

  7. THE UNITED METHOD FOR THE CALCULATION OF SEEPAGE CONTROL BY ADOPTING WEIGHTING SOIL LAYER ON THE BACK SIDE OF DIKE

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Constructing a weighting soil layer at the downstream toe of dike on layered ground is an effective measure to prevent the foundation from blowout failures. In this paper, a series of differential equations describing the seepage flow in layered dike foundation were established, and a united method combining analytic method with one-dimensional finite difference method was proposed for solving the equations. The case study shows that the results calculated by the united method are considerably identical to the computational results of Finite Element Method (FEM), and the united method is very simple and easy compared to the FEM.

  8. Communications systems and methods for subsea processors

    Science.gov (United States)

    Gutierrez, Jose; Pereira, Luis

    2016-04-26

    A subsea processor may be located near the seabed of a drilling site and used to coordinate operations of underwater drilling components. The subsea processor may be enclosed in a single interchangeable unit that fits a receptor on an underwater drilling component, such as a blow-out preventer (BOP). The subsea processor may issue commands to control the BOP and receive measurements from sensors located throughout the BOP. A shared communications bus may interconnect the subsea processor and underwater components and the subsea processor and a surface or onshore network. The shared communications bus may be operated according to a time division multiple access (TDMA) scheme.

  9. Reconnection and Spire Drift in Coronal Jets

    Science.gov (United States)

    Moore, Ronald; Sterling, Alphonse; Falconer, David

    2015-04-01

    It is observed that there are two morphologically-different kinds of X-ray/EUV jets in coronal holes: standard jets and blowout jets. In both kinds: (1) in the base of the jet there is closed magnetic field that has one foot in flux of polarity opposite that of the ambient open field of the coronal hole, and (2) in coronal X-ray/EUV images of the jet there is typically a bright nodule at the edge of the base. In the conventional scenario for jets of either kind, the bright nodule is a compact flare arcade, the downward product of interchange reconnection of closed field in the base with impacted ambient open field, and the upper product of this reconnection is the jet-outflow spire. It is also observed that in most jets of either kind the spire drifts sideways away from the bright nodule. We present the observed bright nodule and spire drift in an example standard jet and in two example blowout jets. With cartoons of the magnetic field and its reconnection in jets, we point out: (1) if the bright nodule is a compact flare arcade made by interchange reconnection, then the spire should drift toward the bright nodule, and (2) if the bright nodule is instead a compact flare arcade made, as in a filament-eruption flare, by internal reconnection of the legs of the erupting sheared-field core of a lobe of the closed field in the base, then the spire, made by the interchange reconnection that is driven on the outside of that lobe by the lobe’s internal convulsion, should drift away from the bright nodule. Therefore, from the observation that the spire usually drifts away from the bright nodule, we infer: (1) in X-ray/EUV jets of either kind in coronal holes the interchange reconnection that generates the jet-outflow spire usually does not make the bright nodule; instead, the bright nodule is made by reconnection inside erupting closed field in the base, as in a filament eruption, the eruption being either a confined eruption for a standard jet or a blowout eruption (as

  10. How Ixtoc 1 was killed

    Energy Technology Data Exchange (ETDEWEB)

    1980-04-01

    More than nine months after it erupted 6/3/79, Petroleos Mexicanos' Ixtoc 1 blowout in Campeche Bay was killed with three cement plugs having a total length of 2885 ft. After drilling of relief wells, 200 sacks of cement were used to form the 685 ft. long bottom plug. After inserting an interval of mud, an additional 200 sacks of cement were pumped down to form a 550 ft. plug. The final up-hole plug was formed by 500 sacks of quick-setting cement, which formed a 1650 ft. long plug.

  11. Electron self-injection during interaction of tightly focused few-cycle laser pulses with underdense plasma

    Science.gov (United States)

    Zhidkov, Alexei; Fujii, Takashi; Nemoto, Koshichi

    2008-09-01

    We study the interaction of short laser pulses tightly focused in a tiny volume proportional to the cube of the pulse wavelength (λ3) with underdense plasma by means of real-geometry particle-in-cell simulations. Underdense plasma irradiated by relatively low-energy λ3 (and λ2 ) laser pulses is shown to be an efficient source of multi-MeV electrons, ˜50nC/J , and coherent hard x rays, despite a strong pulse diffraction. Transverse wave breaking in the vicinity of the laser focus is found to give rise to an immense electron charge loading to the acceleration phase of a laser wake field. A strong blowout regime provoked by the injected electrons resulting in the distribution of accelerated electrons is found for λ3 pulses (further electron acceleration driving by λ2 pulses runs in the usual way). With an increase of pulse energy, wiggling and electron-hose instabilities in the λ3 pulse wake are recognized in the blowout regime. For higher-energy λ3 pulses, the injected beams are well modulated and may serve as a good source of coherent x rays.

  12. The Escape of Ionizing Photons from OB Associations in Disk Galaxies Radiation Transfer Through Superbubbles

    CERN Document Server

    Dove, J B; Ferrara, A; Dove, James B.; Ferrara, Andrea

    1999-01-01

    By solving the time-dependent radiation transfer problem of stellar radiation through evolving superbubbles within a smoothly varying H I distribution, we have estimated the fraction of ionizing photons emitted by OB associations that escapes the H I disk of our Galaxy. We considered a coeval star-formation history and a Gaussian star-formation history with a time spread sigma_t = 2 Myr. We find that the shells of the expanding superbubbles quickly trap or attenuate the ionizing flux, such that most of the escaping radiation escapes shortly after the formation of the superbubble. Superbubbles of large associations can blowout of the H I disk and form dynamic chimneys, which allow the ionizing radiation directly to escape the H I disk. However, blowout occurs when the ionizing photon luminosity has dropped well below the association's maximum luminosity. For the coeval star-formation history, the fraction of photons that escape each side of the disk in the solar vicinity is f_esc approx 6% (the total fraction ...

  13. OBSERVATIONS OF A SERIES OF FLARES AND ASSOCIATED JET-LIKE ERUPTIONS DRIVEN BY THE EMERGENCE OF TWISTED MAGNETIC FIELDS

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Eun-Kyung; Yurchyshyn, Vasyl; Kim, Sujin; Cho, Kyung-Suk; Kumar, Pankaj; Kim, Yeon-Han [Korea Astronomy and Space Science Institute, 776 Daedeokdae-ro, Yuseong-gu, Daejeon 305-348 (Korea, Republic of); Park, Sung-Hong [Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing (IAASARS), National Observatory of Athens, Penteli 15236 (Greece); Chae, Jongchul; Yang, Heesu; Cho, Kyuhyoun; Song, Donguk, E-mail: eklim@kasi.re.kr [Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of)

    2016-01-20

    We studied temporal changes of morphological and magnetic properties of a succession of four confined flares followed by an eruptive flare using the high-resolution New Solar Telescope (NST) operating at the Big Bear Solar Observatory (BBSO) and Helioseismic and Magnetic Imager (HMI) magnetograms and Atmospheric Image Assembly (AIA) EUV images provided by the Solar Dynamics Observatory (SDO). From the NST/Hα and the SDO/AIA 304 Å observations we found that each flare developed a jet structure that evolved in a manner similar to evolution of the blowout jet: (1) an inverted-Y-shaped jet appeared and drifted away from its initial position; (2) jets formed a curtain-like structure that consisted of many fine threads accompanied by subsequent brightenings near the footpoints of the fine threads; and finally, (3) the jet showed a twisted structure visible near the flare maximum. Analysis of the HMI data showed that both the negative magnetic flux and the magnetic helicity have been gradually increasing in the positive-polarity region, indicating the continuous injection of magnetic twist before and during the series of flares. Based on these results, we suggest that the continuous emergence of twisted magnetic flux played an important role in producing successive flares and developing a series of blowout jets.

  14. Wakefield-Induced Ionization injection in beam-driven plasma accelerators

    CERN Document Server

    de la Ossa, A Martinez; Streeter, M J V; Osterhoff, J

    2015-01-01

    We present a detailed analysis of the features and capabilities of Wakefield-Induced Ionization (WII) injection in the blowout regime of beam driven plasma accelerators. This mechanism exploits the electric wakefields to ionize electrons from a dopant gas and trap them in a well-defined region of the accelerating and focusing wake phase, leading to the formation of high-quality witness-bunches. The electron-beam drivers must feature high-peak currents ($I_b^0\\gtrsim 8.5~\\mathrm{kA}$) and a duration comparable to the plasma wavelength to excite plasma waves in the blowout regime and enable WII injection. In this regime, the disparity of the magnitude of the electric field in the driver region and the electric field in the rear of the ion cavity allows for the selective ionization and subsequent trapping from a narrow phase interval. The witness bunches generated in this manner feature a short duration and small values of the normalized transverse emittance ($k_p\\sigma_z \\sim k_p\\epsilon_n \\sim 0.1$). In additi...

  15. Applications to marine disaster prevention spilled oil and gas tracking buoy system

    CERN Document Server

    2017-01-01

    This book focuses on the recent results of the research project funded by a Grant-in-Aid for Scientific Research (S) of the Japan Society for the Promotion of Science (No. 23226017) from FY 2011 to FY 2015 on an autonomous spilled oil and gas tracking buoy system and its applications to marine disaster prevention systems from a scientific point of view. This book spotlights research on marine disaster prevention systems related to incidents involving oil tankers and offshore platforms, approaching these problems from new scientific and technological perspectives. The most essential aspect of this book is the development of a deep-sea underwater robot for real-time monitoring of blowout behavior of oil and gas from the seabed and of a new type of autonomous surface vehicle for real-time tracking and monitoring of oil spill spread and drift on the sea surface using an oil sensor. The mission of these robots is to provide the simulation models for gas and oil blowouts or spilled oil drifting on the sea surface w...

  16. Method for solving an inverse problem of wing type by using a simple panel method; Kanbenna panel ho ni yoru yokugata gyaku mondai no ichikaiho

    Energy Technology Data Exchange (ETDEWEB)

    Ando, J.; Matsumoto, D.; Maita, S.; Nakatake, K. [Kyushu University, Fukuoka (Japan). Faculty of Engineering

    1997-10-01

    This paper describes one method for solving an inverse problem of wing type based on the source and quasi continuous vortex lattice method (SQCM) in designing marine propellers and underwater wings. With the SQCM, vortices and control points are distributed on wing camber according to the QCM, and wing surface is divided into certain number of panels. This is the method to decide vortex intensity and blow-out intensity simultaneously from the condition that vertical speed on the camber and the wing surface is zero, upon having distributed blow-out with certain intensity inside the panel. The method solves the inverse problem with the following process: specific point distribution is so determined that the targeted velocity on the wing surface is satisfied when wing surface pressure distribution and uniform flow velocity are given; and then the panels are so rearranged as in parallel with direction of the flow on the surface of the wing calculated by using these specific points to derive the targeted wing shape. This paper describes the problem solving procedure in great detail. It also introduces examples of numerical calculations. It shows one method for solving the inverse problem in wing type using the SQCM as a simple panel method, whereas its good convergence and stability were verified. Considerations on effects of free surface and expansion of the method into three-dimensional problems will be implemented in the future. 11 refs., 8 figs.

  17. Unexpected Sink for Deepwater Horizon Oil May Influence Future Spill Response

    Science.gov (United States)

    Kinner, Nancy E.; Belden, Laura; Kinner, Peter

    2014-05-01

    A town hall meeting was organized by the Marine Oil Snow Sedimentation and Flocculent Accumulation (MOSSFA) inter-consortia Gulf of Mexico Research Initiative (GoMRI) working group and the Center for Spills in the Environment in conjunction with the Gulf of Mexico Oil Spill and Ecosystem Science Conference. The meeting had the goal of evaluating sedimentation to the seafloor as a significant pathway and fate of oil after the Deepwater Horizon (DwH) well blowout in 2010. About 78,000 cubic meters of crude oil were released into the Gulf of Mexico from a depth of 1500 meters for 86 days, spreading over a large area. Natural and chemically enhanced dispersion, evaporation, dissolution, burning, surface skimming, and direct capture at the wellhead accounted for a significant proportion of the released oil, but the fate of at least 30% of the oil remains unknown. Scientists from different research consortia studying sediments and marine snow in the Gulf began to observe signs of increased sedimentation and hydrocarbon deposition. Sediment mass accumulation rates for the northern Gulf of Mexico increased sixfold to eightfold in 2010, directly following the DwH blowout.

  18. The Complex Neutral Gas Dynamics Of The Dwarf Starburst Galaxy NGC 625

    CERN Document Server

    Cannon, J M; Skillman, E D; Côté, S; Cannon, John M.; Skillman, Evan D.; Cote, Stephanie

    2004-01-01

    We present new multi-configuration HI aperture synthesis imaging of the nearby dwarf starburst galaxy NGC 625 obtained with the Australia Telescope Compact Array. Total HI column density images show gas well-aligned with the optical major axis, and low-column density HI extending to > 6 optical scale lengths. The HI velocity field, on the other hand, is highly disturbed, with neutral gas at nearly all detected velocities within the central region. After considering various interpretations, we find that a blowout scenario most accurately describes the data. Since at our resolution we do not detect any large evacuated holes in the HI disk, we interpret this blowout to be the result of the extended (both spatially and temporally) star formation event which NGC 625 has undergone in the last 100 Myr. This is one of the clearest examples of HI outflow detected in a dwarf galaxy. We find no obvious external trigger for this extended star formation event. We detect strong radio continuum emission from the largest HII...

  19. 8. report of the Standing Senate Committee on energy, the environment and natural resources : facts do not justify banning Canada's current offshore drilling operations : a Senate review in the wake of BP's Deepwater Horizon incident

    Energy Technology Data Exchange (ETDEWEB)

    Angus, W.D.; Mitchell, G. (comps.)

    2010-08-15

    The blowout of BP's Macondo well in the Gulf of Mexico has prompted many drilling practice reviews worldwide. This review by Canada's Senate Committee on Energy, the Environment and Natural Resources investigated Canadian offshore drilling practices. It showed that the risk of an offshore accident is quite low, partly because of the small amount of drilling currently underway in Canada. As a result, the committee recommended against a moratorium on offshore drilling. The study found that Canada's regulations for safety are more stringent than regulations in the United States. This report has elicited further reviews of liability and responsibility issues regarding offshore drilling. The Canadian legislation specifies that oil and gas companies are responsible for all spill clean-up costs and damage compensation. A $30 million absolute liability fund covers blowout costs for drilling in Canada's east offshore coast. A second civil liability fund requires drilling companies to provide Canadian regulators access to $70 million to cover damages from fault or negligence in offshore drilling. In addition, well operators may be required to provide evidence that they have a minimum of $250 million to fund well control, well safety and spill cleanup expenses. This report recommended a comprehensive review of liability, including whether thresholds should be adjusted to reflect current economic realities. refs., tabs., figs.

  20. On the Observation and Simulation of Solar Coronal Twin Jets

    CERN Document Server

    Liu, Jiajia; Wang, Yuming; McIntosh, Scott W; Fan, Yuhong; Zhang, Quanhao

    2016-01-01

    We present the first observation, analysis and modeling of solar coronal twin jets, which occurred after a preceding jet. Detailed analysis on the kinetics of the preceding jet reveals its blowout-jet nature, which resembles the one studied in Liu et al. 2014. However the erupting process and kinetics of the twin jets appear to be different from the preceding one. In lack of the detailed information on the magnetic fields in the twin jet region, we instead use a numerical simulation using a three-dimensional (3D) MHD model as described in Fang et al. 2014, and find that in the simulation a pair of twin jets form due to reconnection between the ambient open fields and a highly twisted sigmoidal magnetic flux which is the outcome of the further evolution of the magnetic fields following the preceding blowout jet. Based on the similarity between the synthesized and observed emission we propose this mechanism as a possible explanation for the observed twin jets. Combining our observation and simulation, we sugges...

  1. Reproducibility of Neonate Ocular Circulation Measurements Using Laser Speckle Flowgraphy

    Directory of Open Access Journals (Sweden)

    Tadashi Matsumoto

    2015-01-01

    Full Text Available Measuring the ocular blood flow in neonates may clarify the relationships between eye diseases and ocular circulation abnormalities. However, no method for noninvasively measuring ocular circulation in neonates is established. We used laser speckle flowgraphy (LSFG modified for neonates to measure their ocular circulation and investigated whether this method is reproducible. During their normal sleep, we studied 16 subjects (adjusted age of 34–48 weeks whose blood flow could be measured three consecutive times. While the subjects slept in the supine position, three mean blur rate (MBR values of the optic nerve head (ONH were obtained: the MBR-A (mean of all values, MBR-V (vessel mean, and MBR-T (tissue mean, and nine blood flow pulse waveform parameters in the ONH were examined. We analyzed the coefficient of variation (COV and the intraclass correlation coefficient (ICC for each parameter. The COVs of the MBR values were all ≤10%. The ICCs of the MBR values were all >0.8. Good COVs were observed for the blowout score, blowout time, rising rate, falling rate, and acceleration time index. Although the measurement of ocular circulation in the neonates was difficult, our results exhibited reproducibility, suggesting that this method could be used in clinical research.

  2. Optimal positron-beam excited plasma wakefields in Hollow and Ion-Wake channels

    CERN Document Server

    Sahai, Aakash A

    2015-01-01

    A positron-beam interacting with the plasma electrons drives radial suck-in, in contrast to an electron-beam driven blow-out in the over-dense regime, $n_b>n_0$. In a homogeneous plasma, the electrons are radially sucked-in from all the different radii. The electrons collapsing from different radii do not simultaneously compress on-axis driving weak fields. A hollow-channel allows electrons from its channel-radius to collapse simultaneously exciting coherent fields. We analyze the optimal channel radius. Additionally, the low ion density in the hollow allows a larger region with focusing phase which we show is linearly focusing. We have shown the formation of an ion-wake channel behind a blow-out electron bubble-wake. Here we explore positron acceleration in the over-dense regime comparing an optimal hollow-plasma channel to the ion-wake channel. The condition for optimal hollow-channel radius is also compared. We also address the effects of a non-ideal ion-wake channel on positron-beam excited fields.

  3. ON THE OBSERVATION AND SIMULATION OF SOLAR CORONAL TWIN JETS

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jiajia; Wang, Yuming; Zhang, Quanhao [CAS Key Laboratory of Geospace Environment, School of Earth and Space Sciences, University of Science and Technology of China, NO. 96, Jinzhai Road, Hefei, Anhui 230026 (China); Fang, Fang [Laboratory for Atmospheric and Space Physics, University of Colorado at Boulder, 1234 Innovation Drive, Boulder, CO 80303 (United States); McIntosh, Scott W.; Fan, Yuhong [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307 (United States)

    2016-02-01

    We present the first observation, analysis, and modeling of solar coronal twin jets, which occurred after a preceding jet. Detailed analysis on the kinetics of the preceding jet reveals its blowout-jet nature, which resembles the one studied in Liu et al. However, the erupting process and kinetics of the twin jets appear to be different from the preceding one. Lacking detailed information on the magnetic fields in the twin jet region, we instead use a numerical simulation using a three-dimensional (3D) MHD model as described in Fang et al., and find that in the simulation a pair of twin jets form due to reconnection between the ambient open fields and a highly twisted sigmoidal magnetic flux, which is the outcome of the further evolution of the magnetic fields following the preceding blowout jet. Based on the similarity between the synthesized and observed emission, we propose this mechanism as a possible explanation for the observed twin jets. Combining our observation and simulation, we suggest that with continuous energy transport from the subsurface convection zone into the corona, solar coronal twin jets could be generated in the same fashion addressed above.

  4. Short-Circuit Making Phase Angle and Tri-Pole Circuit-Breaker Each Pole Breaking Performance%短路合闸相角与三极断路器各极的分断性能

    Institute of Scientific and Technical Information of China (English)

    汤金华

    2012-01-01

    Starting from making phase angle of three-phase short-circuit test, this paper analyzed the different impact of making phase angle on tri-pole circuit-breaker each pole. Comparison of three-phase different rigorous degree was made from recovery voltage, let-through energy, arc energy and peak current after breaking. Due to the difference of the circuit-breaker arc blowout system, the uncertain rule existed, but the system was universally adaptable to the circuit breaker of fine arc blowout performance.%从三相短路试验的合闸相角出发,分析合闸相角对三极断路器各极不同的影响,从分断后的恢复电压、允通能量、电弧能量、峰值电流四个方面比较三相的不同严酷程度,虽然由于断路器灭弧系统性能的差异,该规律存在着不确定性,但普遍适用于灭弧性能良好的断路器。

  5. Predicting The Intrusion Layer From Deep Ocean Oil Spills

    Science.gov (United States)

    Wang, Dayang; Chow, Aaron; Adams, E. Eric

    2015-11-01

    Oil spills from deep ocean blowout events motivate our study of multiphase plumes in a water column. Key to understanding the long-term fate of these plumes is the ability to predict the depth and persistence of intrusion layers. While intrusion layers from multiphase plumes have been studied under stagnant conditions, their behavior in the presence of crossflow, especially in mild crossflow, remains poorly understood. The classical classification of plume behavior identifies two regimes: crossflow-dominant and stratification-dominant--but it does not account for the interplay between the two effects, leaving the transition region unexplored. We conduct laboratory tank experiments to investigate the behavior of intrusion layers under the simultaneous action of crossflow and stratification. Our experiments use an inverted frame of reference, using glass beads with a range of sizes to simulate oil droplets. We find that crossflow creates enhanced mixing, which in turn leads to a shallower intrusion layer of the released fluid (correspondingly, a deeper layer in the case of a deep ocean blowout). We develop a mathematical formulation that extends previous models to account for crossflow effects, and use field observations to validate the analytical and experimental findings.

  6. Experimental and numerical studies of a lean-burn internally-staged combustor

    Institute of Scientific and Technical Information of China (English)

    Fu Zhenbo; Lin Yuzhen; Li Lin; Zhang Chi

    2014-01-01

    A lean-burn internally-staged combustor for low emissions that can be used in civil avi-ation gas turbines is introduced in this paper. The main stage is designed and optimized in terms of fuel evaporation ratio, fuel/air pre-mixture uniformity, and particle residence time using commer-cial computational fluid dynamics (CFD) software. A single-module rectangular combustor is adopted in performance tests including lean ignition, lean blowout, combustion efficiency, emis-sions, and combustion oscillation using aviation kerosene. Furthermore, nitrogen oxides (NOx) emission is also predicted using CFD simulation to compare with test results. Under normal inlet temperature, this combustor can be ignited easily with normal and negative inlet pressures. The lean blowout fuel/air ratio (LBO FAR) at the idle condition is 0.0049. The fuel split proportions between the pilot and main stages are determined through balancing emissions, combustion efficiency, and combustion oscillation. Within the landing and take-off (LTO) cycle, this combustor enables 42%NOx reduction of the standard set by the 6th Committee on Aviation Environmental Protection (CAEP/6) with high combustion efficiency. The maximum board-band pressure oscillations of inlet air and fuel are below 1%of total pressure during steady-state operations at the LTO cycle specific conditions.

  7. Experimental and numerical studies of a lean-burn internally-staged combustor

    Directory of Open Access Journals (Sweden)

    Fu Zhenbo

    2014-06-01

    Full Text Available A lean-burn internally-staged combustor for low emissions that can be used in civil aviation gas turbines is introduced in this paper. The main stage is designed and optimized in terms of fuel evaporation ratio, fuel/air pre-mixture uniformity, and particle residence time using commercial computational fluid dynamics (CFD software. A single-module rectangular combustor is adopted in performance tests including lean ignition, lean blowout, combustion efficiency, emissions, and combustion oscillation using aviation kerosene. Furthermore, nitrogen oxides (NOx emission is also predicted using CFD simulation to compare with test results. Under normal inlet temperature, this combustor can be ignited easily with normal and negative inlet pressures. The lean blowout fuel/air ratio (LBO FAR at the idle condition is 0.0049. The fuel split proportions between the pilot and main stages are determined through balancing emissions, combustion efficiency, and combustion oscillation. Within the landing and take-off (LTO cycle, this combustor enables 42% NOx reduction of the standard set by the 6th Committee on Aviation Environmental Protection (CAEP/6 with high combustion efficiency. The maximum board-band pressure oscillations of inlet air and fuel are below 1% of total pressure during steady-state operations at the LTO cycle specific conditions.

  8. An experimental study on turbulent lifted flames of methane in coflow jets at elevated temperatures

    KAUST Repository

    Choi, Byungchul

    2013-01-01

    An experimental study was conducted on the effects of initial temperature variation on the stabilization characteristics of turbulent nonpremixed flames in coflow jets of methane fuel diluted by nitrogen. The typical behavior seen in the study showed that the liftoff height increased linearly with the jet velocity regardless of the initial temperature in the turbulent regime. Two models were investigated for predicting liftoff heights in the methane jets: the premixed flame model and the large-scale mixing model. For the premixed flame model, the liftoff heights in the methane jets were accurately predicted using the thermal diffusivity of the unburned gas temperature αst,0, instead of that of the burned gas temperature αst,b. For the large-scale mixing model, however, the prediction of liftoff heights differed slightly for the various fuel mole fractions. However, when considering the initial fuel mass fraction YF,0, the liftoff heights were successfully predicted. This result implies that the characteristics of the unburned fuel-air mixture play a crucial role for flame stabilization in coflow jets for a variety of initial conditions. In the turbulent regime, the blowout velocity and the liftoff height at blowout could be accurately predicted by the two models based on a consideration of the physical properties and the buoyancy effect of the initial temperature variation. © 2012 Elsevier Ltd. All rights reserved.

  9. Effect of Spray Cone Angle on Flame Stability in an Annular Gas Turbine Combustor

    Science.gov (United States)

    Mishra, R. K.; Kumar, S. Kishore; Chandel, Sunil

    2016-04-01

    Effect of fuel spray cone angle in an aerogas turbine combustor has been studied using computational fluid dynamics (CFD) and full-scale combustor testing. For CFD analysis, a 22.5° sector of an annular combustor is modeled and the governing equations are solved using the eddy dissipation combustion model in ANSYS CFX computational package. The analysis has been carried out at 125 kPa and 303 K inlet conditions for spray cone angles from 60° to 140°. The lean blowout limits are established by studying the behavior of combustion zone during transient engine operation from an initial steady-state condition. The computational study has been followed by testing the practical full-scale annular combustor in an aerothermal test facility. The experimental result is in a good agreement with the computational predictions. The lean blowout fuel-air ratio increases as the spray cone angle is decreased at constant operating pressure and temperature. At higher spray cone angle, the flame and high-temperature zone moves upstream close to atomizer face and a uniform flame is sustained over a wide region causing better flame stability.

  10. Study on wave power generation of electricity using torsion arc blade type horizontal axis wind turbine; Nejire enko yokugata suihei jiku fusha wo mochiita haryoku hatsuden ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Kojima, N.; Kishimura, K. [Meiji University, Tokyo (Japan)

    1996-10-27

    Windmilling characteristics of a combination of a torsion arc blade type (TABT) horizontal axis wind turbine and a reverse torsion arc blade type (RTABT) horizontal axis wind turbine were evaluated in a wave activated power generation experiment. The TABT wind turbine had six blades, and the front and rear parts of the blade were twisted in the same direction, which caused the direction of rotor rotation to change as the direction of wind along the shaft changed. The RTABT wind turbine had twelve blades, and the front and rear parts of the blade were twisted reverse to each other, which allowed the direction of rotor rotation to stay constant even in the presence of wind direction reversal. To keep the direction of rotor rotation unchanged in the presence of flow direction reversal along the power generating turbine shaft, a single-stage type RTABT wind turbine and a double-stage type were used, the double-stage type being a series connection of a first-stage RTABT (for blowout and suction) and second-stage TABT (for blowout only). Both single-type and double-type rotated in the same direction irrespective of the direction of air flow. The output of the double type was obtained by adding up the values obtained from the individual turbines. The double type was two to three times higher in efficiency than the single type in turbine revolution and power output. 2 refs., 13 figs.

  11. On the Magnetic and Energy Characteristics of Recurrent Homologous Jets from An Emerging Flux

    Science.gov (United States)

    Liu, Jiajia; Wang, Yuming; Erdélyi, Robertus; Liu, Rui; McIntosh, Scott W.; Gou, Tingyu; Chen, Jun; Liu, Kai; Liu, Lijuan; Pan, Zonghao

    2016-12-01

    In this paper, we present the detailed analysis of recurrent homologous jets originating from an emerging negative magnetic flux at the edge of an active region. The observed jets show multithermal features. Their evolution shows high consistence with the characteristic parameters of the emerging flux, suggesting that with more free magnetic energy, the eruptions tend to be more violent, frequent, and blowout-like. The average temperature, average electron number density, and axial speed are found to be similar for different jets, indicating that they should have been formed by plasmas from similar origins. Statistical analysis of the jets and their footpoint region conditions reveals a strong positive relationship between the footpoint region total 131 Å intensity enhancement and jets’ length/width. Stronger linearly positive relationships also exist between the total intensity enhancement/thermal energy of the footpoint regions and jets’ mass/kinetic/thermal energy, with higher cross-correlation coefficients. All the above results together confirm the direct relationship between the magnetic reconnection and the jets and validate the important role of magnetic reconnection in transporting large amounts of free magnetic energy into jets. It is also suggested that there should be more free energy released during the magnetic reconnection of blowout than of standard jet events.

  12. Precision Dual-Aquifer Dewatering at a Low Level Radiological Cleanup in New Jersey

    Energy Technology Data Exchange (ETDEWEB)

    Gosnell, A. S.; Langman, J. W. Jr.; Zahl, H. A.; Miller, D. M.

    2002-02-27

    Cleanup of low-level radioactive wastes at the Wayne Interim Storage Site (WISS), Wayne, New Jersey during the period October, 2000 through November, 2001 required the design, installation and operation of a dual-aquifer dewatering system to support excavation of contaminated soils. Waste disposal pits from a former rare-earth processing facility at the WISS had been in contact with the water table aquifer, resulting in moderate levels of radionuclides being present in the upper aquifer groundwater. An uncontaminated artesian aquifer underlies the water table aquifer, and is a localized drinking water supply source. The lower aquifer, confined by a silty clay unit, is flowing artesian and exhibits potentiometric heads of up to 4.5 meters above grade. This high potentiometric head presented a strong possibility that unloading due to excavation would result in a ''blowout'', particularly in areas where the confining unit was < 1 meter thick. Excavation of contaminated materials w as required down to the surface of the confining unit, potentially resulting in an artesian aquifer head of greater than 8 meters above the excavation surface. Consequently, it was determined that a dual-aquifer dewatering system would be required to permit excavation of contaminated material, with the water table aquifer dewatered to facilitate excavation, and the deep aquifer depressurized to prevent a ''blowout''. An additional concern was the potential for vertical migration of contamination present in the water table aquifer that could result from a vertical gradient reversal caused by excessive pumping in the confined system. With these considerations in mind, a conceptual dewatering plan was developed with three major goals: (1) dewater the water table aquifer to control radionuclide migration and allow excavation to proceed; (2) depressurize the lower, artesian aquifer to reduce the potential for a ''blowout''; and (3

  13. A BOP Control System with Pneumatic Pressure Test Function%一种带气动试压功能的防喷器控制装置

    Institute of Scientific and Technical Information of China (English)

    孟少辉; 陈慧慧; 蒋楠; 何伟红; 段马利; 黄建生

    2015-01-01

    For oilfield connected components need to be installed before and after the demand pressure and tightness testing, developed a wellhead blowout preventer both control groups (and the hydraulic valve) can facilitate the blowout preventer on the wellhead equipment and connecting tube sinks and valves be pressure and tightness testing of the new BOP control device that achieved in the fields of drilling, work over process of the blowout preventer, the throttle control manifold, riser, casing, flange, sealed containers and other components for on-site testing capabilities to solve the removed parts sent to the repair shop test on a dedicated test equipment for the duration of the prob-lem caused. At present, the device has completed the trial, and has been successfully applied in the oil field.%针对油田对连接部件在安装前后需进行耐压及密封性测试的需求,研制了一种既能控制井口防喷器组(和液动阀)又能方便地对井口防喷设备及其连接管汇和阀件进行耐压和密封性测试的新型防喷器控制装置,该装置实现了在油田的钻井、修井作业过程中对防喷器、节流控制管汇、立管、套管、法兰、密封容器等部件进行现场测试的功能,解决了拆下试验部件送往修理厂在专用设备上进行测试造成的工期问题。目前该装置已完成试制,并已在油田现场成功应用。

  14. 油田生产设施环境安全距离理论与案例分析%The Theory and Case Analysis of Environmentally Safe Distance for Oilfield Production Facilities

    Institute of Scientific and Technical Information of China (English)

    李娜; 张震; 冷飞

    2012-01-01

    In order to protect the environment as well as the personal and property security of residents surrounding the oilfield,it is an economic and effective way of environmental protection and safety management to set a scientific environmentally safe distance between the oilfield facilities and the different function districts around.This article presents the concept of environmentally safe distance for oilfield facilities,the estimation model for the environmentally safe distance for toxic blowout,noise pollution,pipeline leak,and fire explosion,and the estimation method of three types of oilfield facility: well site,terminal station,and pipeline.In the last part,this article conducts the estimation of environmentally safe distance for toxic hydrogen sulfide blowout with the example of the catastrophic "12.23" Kai Town blowout accident in Chongqing,the conclusion of which is proved to be accurate and reliable after compared to the actual situation.%为保护油田生产设施周围环境及居民人身财产安全,在油田设施和周围不同环境功能区之间设置科学的环境安全距离,是一种经济、有效的环境保护与安全管理措施.文章提出油田生产设施环境安全距离的概念,以及有毒气体井喷泄漏、噪声污染、管线泄漏和火灾爆炸的环境安全距离估算模式,将油田生产设施分为井场、站库和管线三类,提出环境安全距离估算方法.最后以重庆开县“12·23”特大井喷事故为例,对硫化氢毒气井喷泄漏的环境安全距离进行估算,与实际情况相对比后证明估算结果可靠.

  15. Effects of fuel structure on emissions and stability in the well-stirred reactor

    Science.gov (United States)

    Blust, James W.

    The design and development of low-emissions aero and industrial gas turbine combustors is challenging because it entails satisfying emissions regulations without conflicting with performance improvements. Efforts to reduce emissions have typically ignored the variability in emissions that can result from change in fuel type. Consequently, it is desirable to investigate fuel effects on emissions and performance characteristics of the combustor under realistic operating conditions. The well stirred reactor (WSR) is a laboratory combustor with two uses: (a) it provides a laboratory idealization of a highly mixed gas turbine combustor; (b) it emulates the perfectly stirred reactor condition for use in measuring kinetics parameters and data to compare to kinetics models of gas turbine fuels. The WSR was used to study lean blow-out limits and emissions from a variety of fuels. In particular, effects of residence time and flame temperature on lean blow-out limits, NOsbx, CO, and unburned hydrocarbon (UHC) emissions were measured from normal and cyclic alkanes, aromatics and hydrocarbon mixes. It was found that CO and UHC emissions increase with increasing carbon number of the fuel, with methane being an exception. NOsbx emissions increase with increasing carbon to hydrogen ratio of the fuel. Results showed that hydrocarbon structure plays a significant role in determining lean blow-out limits, combustion efficiency, and pollutant emissions. From this study, the global activation energies of methane and ethane were measured during lean combustion. Also, empirical formulae to predict NOsbx formation and minimal production of CO as a function of fuel characteristics are given. Emissions data from the WSR were compared to simulations by detailed kinetic modeling of the combustion of methane, ethane, n-heptane, toluene, ethylbenzene, Jet A and cracked fuel simulant. Computations are generally in excellent qualitative agreement with experimental observation for all fuels

  16. On the unusual gas composition in the Beta Pictoris debris disk

    CERN Document Server

    Xie, Ji-Wei; Wu, Yanqin

    2012-01-01

    The metallic gas associated with the Beta Pic debris disk is believed to not be primordial, but arise during the destruction of dust grains. Recent observations have shown that carbon and oxygen in this gas are exceptionally overabundant compared to other elements, by some 400 times. We study the origin of this enrichment under two opposing hypothesis, preferential production, where the gas is produced with the observed unusual abundance, and preferential depletion, where the gas evolves to the observed state from an original solar abundance under a number of dynamical processes. We include in our study the following processes: radiative blow-out of metallic elements, dynamical coupling between different species, and viscous accretion onto the star. We find that, if gas viscosity is sufficiently low (the conventional alpha parameter 1e-1, as expected for this largely ionized disk), gas is continuously produced and viscously accreted toward the star. This removal process does not discriminate between elements ...

  17. Propagation of λ3 Laser Pulses in Underdense Plasma

    Science.gov (United States)

    Zhidkov, Alexei; Nemoto, Koshichi; Nayuki, Takuya; Oishi, Yuji; Fujii, Takashi

    2008-06-01

    We study the interaction of λ3 laser pulses with underdense plasma by means of real geometry particle-in-cell simulation. Underdense plasma irradiated by even low energy λ3 laser pulses can be an efficient source of multi-MeV electrons, ˜50 nC/J. The electron acceleration driven by low energy λ3 and λ2 laser pulses is monitored by means of fully relativistic 3D particle-in- cell simulation. Strong transverse wave-breaking in the vicinity of the laser focus is found to give rise to an immense electron charge injected to the acceleration phase of laser wake field. While the acceleration by λ2 pulses runs in usual way, strong blowout regime is found for λ3 pulses. Details of laser pulse self-guiding are discussed.

  18. Fallacies of composition in nonlinear marketing models

    Science.gov (United States)

    Bischi, Gian Italo; Cerboni Baiardi, Lorenzo

    2015-01-01

    In this paper we consider some nonlinear discrete-time dynamic models proposed in the literature to represent marketing competition, and we use these models to critically discuss the statement, often made in economic literature, that identical agents behave identically and quasi-identical ones behave in a similar way. We show, through examples and some general mathematical statements, that the one-dimensional model of a representative agent, whose dynamics summarize the common behavior of identical interacting agents, may be misleading. In order to discuss these topics some simple methods for the study of local stability and bifurcations are employed, as well as numerical examples where some results taken from the literature on chaos synchronization are applied to two-dimensional marketing models that exhibit riddling, blowout and other global phenomena related to the existence of measure-theoretic attractors.

  19. AGN-starburst evolutionary connection : a physical interpretation based on radiative feedback

    CERN Document Server

    Ishibashi, W

    2016-01-01

    Observations point towards a close connection between nuclear starbursts, active galactic nuclei (AGN), and outflow phenomena. An evolutionary sequence, starting from a dust-obscured ultra-luminous infrared galaxy and eventually leading to an unobscured optical quasar, has been proposed and discussed in the literature. AGN feedback is usually invoked to expel the obscuring gas and dust in a blow-out event, but the underlying physical mechanism remains unclear. We consider AGN feedback driven by radiation pressure on dust, which directly acts on the obscuring dusty gas. We obtain that radiative feedback can potentially disrupt dense gas in the infrared-optically thick regime, and that an increase in the dust-to-gas fraction leads to an increase in the effective Eddington ratio. Thus the more dusty gas is preferentially expelled by radiative feedback, and the central AGN is prone to efficiently remove its own obscuring dust cocoon. Large amounts of dust imply heavy obscuration but also powerful feedback, sugges...

  20. Macondo-1 well oil-derived polycyclic aromatic hydrocarbons in mesozooplankton from the northern Gulf of Mexico

    Science.gov (United States)

    Mitra, Siddhartha; Kimmel, David G.; Snyder, Jessica; Scalise, Kimberly; McGlaughon, Benjamin D.; Roman, Michael R.; Jahn, Ginger L.; Pierson, James J.; Brandt, Stephen B.; Montoya, Joseph P.; Rosenbauer, Robert J.; Lorenson, T.D.; Wong, Florence L.; Campbell, Pamela L.

    2012-01-01

    Mesozooplankton (>200 μm) collected in August and September of 2010 from the northern Gulf of Mexico show evidence of exposure to polycyclic aromatic hydrocarbons (PAHs). Multivariate statistical analysis revealed that distributions of PAHs extracted from mesozooplankton were related to the oil released from the ruptured British Petroleum Macondo-1 (M-1) well associated with the R/VDeepwater Horizon blowout. Mesozooplankton contained 0.03–97.9 ng g−1 of total PAHs and ratios of fluoranthene to fluoranthene + pyrene less than 0.44, indicating a liquid fossil fuel source. The distribution of PAHs isolated from mesozooplankton extracted in this study shows that the 2010 Deepwater Horizon spill may have contributed to contamination in the northern Gulf of Mexico ecosystem.

  1. Time varying voltage combustion control and diagnostics sensor

    Science.gov (United States)

    Chorpening, Benjamin T.; Thornton, Jimmy D.; Huckaby, E. David; Fincham, William

    2011-04-19

    A time-varying voltage is applied to an electrode, or a pair of electrodes, of a sensor installed in a fuel nozzle disposed adjacent the combustion zone of a continuous combustion system, such as of the gas turbine engine type. The time-varying voltage induces a time-varying current in the flame which is measured and used to determine flame capacitance using AC electrical circuit analysis. Flame capacitance is used to accurately determine the position of the flame from the sensor and the fuel/air ratio. The fuel and/or air flow rate (s) is/are then adjusted to provide reduced flame instability problems such as flashback, combustion dynamics and lean blowout, as well as reduced emissions. The time-varying voltage may be an alternating voltage and the time-varying current may be an alternating current.

  2. Leak in spiral weld in a 16 inches gas pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Fazzini, Pablo G.; Bona, Jeremias de [GIE S.A., Mar del Plata (Argentina); Otegui, Jose L. [University of Mar del Plata (Argentina)

    2009-07-01

    This paper discusses a failure analysis after a leak in the spiral weld of a 16 inches natural gas pipeline, in service since 1974. The leak was the result of the coalescence of two different defects, on each surface of the pipe wall, located in the center of the inner cord of the helical DSAW weld. Fractographic and metallographic studies revealed that the leak was a combination of three conditions. During fabrication of the pipe, segregation in grain boundary grouped in mid weld. During service, these segregations underwent a process of selective galvanic corrosion. One of these volumetric defects coincided with a tubular pore in the outer weld. Pigging of the pipeline in 2005 for cleaning likely contributed to the increase of the leak flow, when eliminating corrosion product plugs. Although these defects are likely to repeat, fracture mechanics shows that a defect of this type is unlikely to cause a blowout. (author)

  3. Multispot fiber laser welding

    DEFF Research Database (Denmark)

    Schutt Hansen, Klaus

    This dissertation presents work and results achieved in the field of multi beam fiber laser welding. The project has had a practical approach, in which simulations and modelling have been kept at a minimum. Different methods to produce spot patterns with high power single mode fiber lasers have...... been possible to control the welding width in incremental steps by adding more beams in a row. The laser power was used to independently control the keyhole and consequently the depth of fusion. An example of inline repair of a laser weld in butt joint configuration was examined. Zinc powder was placed...... in the weld causing expulsion of the melt pool. Trailing beams were applied to melt additional material and ensure a melt pool. The method showed good results for increasing tolerances to impurities and reduction of scrapped parts from blowouts during laser welding....

  4. Supernovae and their expanding blast waves during the early evolution of Galactic globular clusters

    CERN Document Server

    Tenorio-Tagle, Guillermo; Silich, Sergiy; Cassisi, Santi

    2015-01-01

    Our arguments deal with the early evolution of Galactic globular clusters and show why only a few of the supernovae products were retained within globular clusters and only in the most massive cases ($M \\ge 10^6$ Msol), while less massive clusters were not contaminated at all by supernovae. Here we show that supernova blast waves evolving in a steep density gradient undergo blowout and end up discharging their energy and metals into the medium surrounding the clusters. This inhibits the dispersal and the contamination of the gas left over from a first stellar generation. Only the ejecta from well centered supernovae, that evolve into a high density medium available for a second stellar generation in the most massive clusters would be retained. These are likely to mix their products with the remaining gas, leading in these cases eventually to an Fe contaminated second stellar generation.

  5. Electron beam manipulation, injection and acceleration in plasma wakefield accelerators by optically generated plasma density spikes

    Science.gov (United States)

    Wittig, Georg; Karger, Oliver S.; Knetsch, Alexander; Xi, Yunfeng; Deng, Aihua; Rosenzweig, James B.; Bruhwiler, David L.; Smith, Jonathan; Sheng, Zheng-Ming; Jaroszynski, Dino A.; Manahan, Grace G.; Hidding, Bernhard

    2016-09-01

    We discuss considerations regarding a novel and robust scheme for optically triggered electron bunch generation in plasma wakefield accelerators [1]. In this technique, a transversely propagating focused laser pulse ignites a quasi-stationary plasma column before the arrival of the plasma wake. This localized plasma density enhancement or optical "plasma torch" distorts the blowout during the arrival of the electron drive bunch and modifies the electron trajectories, resulting in controlled injection. By changing the gas density, and the laser pulse parameters such as beam waist and intensity, and by moving the focal point of the laser pulse, the shape of the plasma torch, and therefore the generated trailing beam, can be tuned easily. The proposed method is much more flexible and faster in generating gas density transitions when compared to hydrodynamics-based methods, and it accommodates experimentalists needs as it is a purely optical process and straightforward to implement.

  6. Game story space of professional sports: Australian rules football.

    Science.gov (United States)

    Kiley, Dilan Patrick; Reagan, Andrew J; Mitchell, Lewis; Danforth, Christopher M; Dodds, Peter Sheridan

    2016-05-01

    Sports are spontaneous generators of stories. Through skill and chance, the script of each game is dynamically written in real time by players acting out possible trajectories allowed by a sport's rules. By properly characterizing a given sport's ecology of "game stories," we are able to capture the sport's capacity for unfolding interesting narratives, in part by contrasting them with random walks. Here we explore the game story space afforded by a data set of 1310 Australian Football League (AFL) score lines. We find that AFL games exhibit a continuous spectrum of stories rather than distinct clusters. We show how coarse graining reveals identifiable motifs ranging from last-minute comeback wins to one-sided blowouts. Through an extensive comparison with biased random walks, we show that real AFL games deliver a broader array of motifs than null models, and we provide consequent insights into the narrative appeal of real games.

  7. Thermal explosion in a combustible gas containing fuel droplets

    Science.gov (United States)

    McIntosh, A. C.; Gol'dshtein, V.; Goldfarb, I.; Zinoviev, A.

    1998-06-01

    An original physical model of self-ignition in a combustible gas mixture containing liquid fuel droplets is developed. The droplets are small enough for the gas-droplet mixture to be considered as a fine mist such that individual droplet burning is subsumed into a well-stirred, spatially invariant burning approximation. A classical Semenov-type analysis is used to describe the exothermic reaction, and the endothermic terms involve the use of quasi-steady mass transfer/heat balance and the Clausius-Clapeyron evaporative law. The resulting analysis predicts the ignition delay which is a function of the system parameters. Results are given for typical dynamical regimes. The case of different initial temperatures for droplets and gas is highly relevant to gas turbine lean blow-out and re-ignition.

  8. Penetrating injury of orbital roof and brain sparing the eye ball in a pediatric patient: A rare occurrence

    Directory of Open Access Journals (Sweden)

    Vikul Kumar

    2016-01-01

    Full Text Available Blowout fractures are a common occurrence in traumatic brain injury patients. In pediatric age group, orbital floor fracture is a common occurrence. We report a case of 2-year-old male admitted to trauma center, with penetrating injury to the left eye by the clutch of motorbike which fell on the child. Noncontrast computed tomography scan revealed fracture of the roof of left orbit with left frontal contusion sparing the left eyeball. There was also the continuous leak of brain matter from the left eye which suggested tear of dura mater. Urgent left frontal craniotomy was done with the evacuation of contusion, reconstruction of orbital roof, and duroplasty under general anesthesia.

  9. Tracking hydrocarbon plume transport and biodegradation at Deepwater Horizon.

    Science.gov (United States)

    Camilli, Richard; Reddy, Christopher M; Yoerger, Dana R; Van Mooy, Benjamin A S; Jakuba, Michael V; Kinsey, James C; McIntyre, Cameron P; Sylva, Sean P; Maloney, James V

    2010-10-08

    The Deepwater Horizon blowout is the largest offshore oil spill in history. We present results from a subsurface hydrocarbon survey using an autonomous underwater vehicle and a ship-cabled sampler. Our findings indicate the presence of a continuous plume of oil, more than 35 kilometers in length, at approximately 1100 meters depth that persisted for months without substantial biodegradation. Samples collected from within the plume reveal monoaromatic petroleum hydrocarbon concentrations in excess of 50 micrograms per liter. These data indicate that monoaromatic input to this plume was at least 5500 kilograms per day, which is more than double the total source rate of all natural seeps of the monoaromatic petroleum hydrocarbons in the northern Gulf of Mexico. Dissolved oxygen concentrations suggest that microbial respiration rates within the plume were not appreciably more than 1 micromolar oxygen per day.

  10. Monitoring and Modeling the Deepwater Horizon Oil Spill: A Record-Breaking Enterprise

    Science.gov (United States)

    Schultz, Colin

    2013-05-01

    On 20 April 2010, an explosion on the Deepwater Horizon oil drilling platform killed 11 people, and the subsequent blowout of the deepwater wellhead sparked one of the most costly oil spills in history. In the days and months that followed, researchers and disaster response crews flocked to the Gulf of Mexico to study, assess, and guide cleanup operations. In the AGU monograph Monitoring and Modeling the Deepwater Horizon Oil Spill: A Record-Breaking Enterprise, editors Yonggang Liu, Amy MacFadyen, Zhen-Gang Ji, and Robert H. Weisberg pull together the results of the state-of-the-art rapid response research conducted during the Gulf oil spill. Here Eos talks to Yonggang Liu.

  11. 吸取经验教训 健全安全保障体系——墨西哥湾漏油事件的启示

    Institute of Scientific and Technical Information of China (English)

    张抗

    2010-01-01

    2010年4月20号位于墨西哥湾超深水区马孔多(Macondo)区块上的MC252井正作业的深水地平线号(Deepwater Horizon)钻井平台起火爆炸沉没,继而导致海底防喷器(BOP,Blowout Preventer)失控,大量原油持续喷溢,形成严重的环境污染。当时井位水深约5000ft(1525m),已达井深18000多英尺(约5490余米)。

  12. 深水动力定位钻完井作业的风险管理探述%Risk Management of Deepwater Drilling and Completion Operations Using DP Drilling Units

    Institute of Scientific and Technical Information of China (English)

    刘潇; 谢彬

    2012-01-01

    This paper analyzes the cause of deepwater horizon blowout accident and the risk of position loss during drilling and completion operation using the concept of well integrity double barriers. A risk management framework is also proposed for the management of deepwater drilling and completion operations using DP drilling units.%运用井口完整性双安全屏障的概念分析了深海地平线号井喷事故的原因和动力定位平台在动力定位模式下进行钻完井作业时由移位引起的井喷风险,并就动力定位钻完井作业的风险管理提出相关的建议.

  13. Aneurysmal bone cyst: Rarity in mandible and its ambiguity with Central giant cell granuloma

    Directory of Open Access Journals (Sweden)

    Anagha Shete

    2012-01-01

    Full Text Available The aneurysmal bone cyst is an uncommon lesion which has been found in most bones of the skeleton, although the majority occur in the long bones and in the spine. It was first described as a distinct clinical entity by Jaffe and Lichenstein in 1942 to describe the -characteristic "blow-out" of the bone seen in the radiographs of the lesion. In the past, the lesion has been classified as an atypical giant cell tumor or benign bone cyst. We report a case of an aneurysmal bone cyst in an 18-year-old patient who reported with the chief complaint of swelling on the right side of the face since 4 months. It was non-tender, non-fluctuant, and hard in consistency. Radiographic examination revealed a large, expansile, multilocular lesion suggestive of benign odontogenic tumor. Complete enucleation was carried out and the final histopathologic diagnosis of aneurysmal bone cyst was given.

  14. An ATCA Observation of the Youngest Known Galactic SNR G1.9+0.3

    CERN Document Server

    De Horta, A Y; Crawford, E J; Stootman, F H; Pannuti, T G

    2008-01-01

    We present an analysis of a previously unpublished radio-continuum observation of SNR G1.9+0.3 which at an age of <=150 years is the youngest known in the Galaxy. The observations were made in 1993 using the Australia Telescope Compact Array (ATCA) at two 6-cm frequencies. We note two previously unseen blow-out structures in the north and south direcions. We estimate a flux density of 1.545Jy, an outer diameter of ~80" and confirm an expansion rate of ~0.65% per year between 1985 and 2008. No polarisation was detected in the radio emission from SNR G1.9+0.3 above the 1% level. We also present these previously unpublished results as a high resolution reference point from which to study the evolution of SNRs at times for which there is a gap in our knowledge.

  15. SUPERNOVAE AND THEIR EXPANDING BLAST WAVES DURING THE EARLY EVOLUTION OF GALACTIC GLOBULAR CLUSTERS

    Energy Technology Data Exchange (ETDEWEB)

    Tenorio-Tagle, Guillermo; Silich, Sergiy [Instituto Nacional de Astrofísica Óptica y Electrónica, AP 51, 72000 Puebla, México (Mexico); Muñoz-Tuñón, Casiana [Instituto de Astrofísica de Canarias (Spain); Cassisi, Santi, E-mail: gtt@inaoep.mx, E-mail: cmt@iac.es, E-mail: cassisi@oa-teramo.inaf.it [INAF—Astronomical Observatory of Collurania, via M. Maggini, I-64100 Teramo (Italy)

    2015-11-20

    Our arguments deal with the early evolution of Galactic globular clusters and show why only a few of the supernovae (SNe) products were retained within globular clusters and only in the most massive cases (M ≥ 10{sup 6} M{sub ⊙}), while less massive clusters were not contaminated at all by SNe. Here, we show that SN blast waves evolving in a steep density gradient undergo blowout and end up discharging their energy and metals into the medium surrounding the clusters. This inhibits the dispersal and the contamination of the gas left over from a first stellar generation. Only the ejecta from well-centered SNe that evolve into a high-density medium available for a second stellar generation (2SG) in the most massive clusters would be retained. These are likely to mix their products with the remaining gas, eventually leading in these cases to an Fe-contaminated 2SG.

  16. Coral communities as indicators of ecosystem-level impacts of the Deepwater Horizon spill

    Science.gov (United States)

    Fisher, Charles R.; Demopoulos, Amanda W.J.; Cordes, Erik E.; Baums, Iliana B.; White, Helen K.; Bourque, Jill R.

    2014-01-01

    The Macondo oil spill released massive quantities of oil and gas from a depth of 1500 meters. Although a buoyant plume carried released hydrocarbons to the sea surface, as much as half stayed in the water column and much of that in the deep sea. After the hydrocarbons reached the surface, weathering processes, burning, and the use of a dispersant caused hydrocarbon-rich marine snow to sink into the deep sea. As a result, this spill had a greater potential to affect deep-sea communities than had any previous spill. Here, we review the literature on impacts on deep-sea communities from the Macondo blowout and provide additional data on sediment hydrocarbon loads and the impacts on sediment infauna in areas with coral communities around the Macondo well. We review the literature on the genetic connectivity of deep-sea species in the Gulf of Mexico and discuss the potential for wider effects on deep Gulf coral communities.

  17. Preventable disasters in the offshore oil industry: from Piper Alpha to Deepwater Horizon.

    Science.gov (United States)

    Woolfson, Charles

    2012-01-01

    This article compares two industrial disasters in the offshore oil industry, the explosion and fire on Piper Alpha off the coast of Scotland in 1988, the world's worst offshore disaster, and the blowout and explosions on Deepwater Horizon in the Gulf of Mexico in 2010. It attempts to answer a simple question: Given the enormity of the first tragedy and the careful analysis of its circumstances and causes, why were the lessons of previous failure not learned by this globally organized industry, in the very heartland in the United States? The answer tells us much about the ability of corporate capital to configure regulatory regimes in its own interests and to do so in a manner that continues to threaten the safety and well-being of its employees and the wider environment.

  18. Numerical simulation on bucking distortion of aluminum alloy thin-plate weldment

    Institute of Scientific and Technical Information of China (English)

    Jun LI; Jian-guo YANG; Ha-Mong LI; De-jun YAN; Hong-yuan FANG

    2009-01-01

    In this paper, the welding residual distortion of aluminum alloy thin plates is predicted using the elasticity-plasticity finite element method (FEM). The factors contributing to the welding buckling distortion of thin plates are studied by investigating the formation and evolution process of welding stresses. Results of experi-ments and numerical simulations show that the buckling appearance of thin-plate aluminum alloy weldments is asymmetrical in the welding length direction, and the maximum longitudinal deflection appears at the position a certain distance from the middle point of the side edge towards the arc-starting end. The angular deformation direction of thin-plate weldments is not fixed, and such case as the angular deformation value of the arc-starting end being higher than that of the arc-blowout end exists.

  19. Rigid Finite Element Method in Analysis of Dynamics of Offshore Structures

    CERN Document Server

    Wittbrodt, Edmund; Maczyński, Andrzej; Wojciech, Stanisław

    2013-01-01

    This book describes new methods developed for modelling dynamics of machines commonly used in the offshore industry. These methods are based both on the rigid finite element method, used for the description of link deformations, and on homogeneous transformations and joint coordinates, which is applied to the modelling of multibody system dynamics. In this monograph, the bases of the rigid finite element method  and homogeneous transformations are introduced. Selected models for modelling dynamics of offshore devices are then verified both by using commercial software, based on the finite element method, as well as by using additional methods. Examples of mathematical models of offshore machines, such as a gantry crane for Blowout-Preventer (BOP) valve block transportation, a pedestal crane with shock absorber, and pipe laying machinery are presented. Selected problems of control in offshore machinery as well as dynamic optimization in device control are also discussed. Additionally, numerical simulations of...

  20. New methodology for gas migration prediction before oil well cementing

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, G.H.V.P.; Martins, A.L.; Rocha, J.M.S. [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)], E-mail: gustavo_cep@yahoo.com.br; Martinelli, A.E. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2012-04-15

    Many challenges have been presented in oil well drilling including preventing gas migration after cementing operations. This phenomenon is potentially dangerous since the gas can migrate to the surface causing the annular pressurization or lead to a blowout with catastrophic results that may include the loss of the well. If the hydrostatic pressure in front of the gas zone becomes lower than the pressure in this zone, the gas will invade the well. This work presents a comprehensive methodology to evaluate gas migration after cementing operations taking into account the critical static gel strength concept associated with time dependent viscosity behavior. A mechanistic model based on a force balance acting on gas bubble was proposed to predict the bubble displacement through the cement slurry while it gels and evaluate if the hydraulic isolation will be affected allowing project operation changes to ensure well construction safely. (author)

  1. A Novel Cardiotoxic Mechanism for a Pervasive Global Pollutant

    Science.gov (United States)

    Brette, Fabien; Shiels, Holly A.; Galli, Gina L. J.; Cros, Caroline; Incardona, John P.; Scholz, Nathaniel L.; Block, Barbara A.

    2017-01-01

    The Deepwater Horizon disaster drew global attention to the toxicity of crude oil and the potential for adverse health effects amongst marine life and spill responders in the northern Gulf of Mexico. The blowout released complex mixtures of polycyclic aromatic hydrocarbons (PAHs) into critical pelagic spawning habitats for tunas, billfishes, and other ecologically important top predators. Crude oil disrupts cardiac function and has been associated with heart malformations in developing fish. However, the precise identity of cardiotoxic PAHs, and the mechanisms underlying contractile dysfunction are not known. Here we show that phenanthrene, a PAH with a benzene 3-ring structure, is the key moiety disrupting the physiology of heart muscle cells. Phenanthrene is a ubiquitous pollutant in water and air, and the cellular targets for this compound are highly conserved across vertebrates. Our findings therefore suggest that phenanthrene may be a major worldwide cause of vertebrate cardiac dysfunction.

  2. Applications of science and engineering to quantify and control the Deepwater Horizon oil spill

    Science.gov (United States)

    McNutt, Marcia K.; Chu, Steven; Lubchenco, Jane; Hunter, Tom; Dreyfus, Gabrielle; Murawski, Steven A.; Kennedy, David M.

    2012-01-01

    The unprecedented engagement of scientists from government, academia, and industry enabled multiple unanticipated and unique problems to be addressed during the Deepwater Horizon oil spill. During the months between the initial blowout on April 20, 2010, and the final well kill on September 19, 2010, researchers prepared options, analyses of tradeoffs, assessments, and calculations of uncertainties associated with the flow rate of the well, well shut in, killing the well, and determination of the location of oil released into the environment. This information was used in near real time by the National Incident Commander and other government decision-makers. It increased transparency into BP’s proposed actions and gave the government confidence that, at each stage proposed, courses of action had been thoroughly vetted to reduce risk to human life and the environment and improve chances of success.

  3. Game story space of professional sports: Australian rules football

    Science.gov (United States)

    Kiley, Dilan Patrick; Reagan, Andrew J.; Mitchell, Lewis; Danforth, Christopher M.; Dodds, Peter Sheridan

    2016-05-01

    Sports are spontaneous generators of stories. Through skill and chance, the script of each game is dynamically written in real time by players acting out possible trajectories allowed by a sport's rules. By properly characterizing a given sport's ecology of "game stories," we are able to capture the sport's capacity for unfolding interesting narratives, in part by contrasting them with random walks. Here we explore the game story space afforded by a data set of 1310 Australian Football League (AFL) score lines. We find that AFL games exhibit a continuous spectrum of stories rather than distinct clusters. We show how coarse graining reveals identifiable motifs ranging from last-minute comeback wins to one-sided blowouts. Through an extensive comparison with biased random walks, we show that real AFL games deliver a broader array of motifs than null models, and we provide consequent insights into the narrative appeal of real games.

  4. The game story space of professional sports: Australian Rules Football

    CERN Document Server

    Kiley, D P; Mitchell, L; Danforth, C M; Dodds, P S

    2015-01-01

    Sports are spontaneous generators of stories. Through skill and chance, the script of each game is dynamically written in real time by players acting out possible trajectories allowed by a sport's rules. By properly characterizing a given sport's ecology of `game stories', we are able to capture the sport's capacity for unfolding interesting narratives, in part by contrasting them with random walks. Here, we explore the game story space afforded by a data set of 1,310 Australian Football League (AFL) score lines. We find that AFL games exhibit a continuous spectrum of stories and show how coarse-graining reveals identifiable motifs ranging from last minute comeback wins to one-sided blowouts. Through an extensive comparison with a random walk null model, we show that AFL games are superdiffusive and deliver a much broader array of motifs, and we provide consequent insights into the narrative appeal of real games.

  5. Clumps and Axisymmetric Features in Debris Discs

    CERN Document Server

    Jiang, Ing-Guey

    2013-01-01

    This paper studied the structures of debris discs, focusing on the conditions that can form an axisymmetric-looking outer disc from systems with inner clumps. The main conclusion was that as long as the dominated dust grains are smaller than the blowout size, it is easy to form an axisymmetric-looking outer debris disc, which is part of a quasi-steady state of the whole system. This quasi-steady state is established through the balance between grain generations and a continuous out-going grain flow. Assuming there is an event that starts planetesimal collisions and the corresponding grain generations, this balance can be approached in a few thousand years. This result suggested that a quasi-steady-state picture could solve the possible mass budget problem of Vega's outer debris disc.

  6. 糖厂锅炉爆管原因分析及对策%Analysis and countermeasures of sugar refinery boiler tube blasting

    Institute of Scientific and Technical Information of China (English)

    孔树学

    2012-01-01

    The sugar refinery boiler two successive water-wall tubes pipe explosion, through the pipe explosion running record check, after a broken tube boiler internal, blasting the shape of the mouth, blasting as pipe diameter changes, organize and performance of blasting mouth changes and tube wall and scaling inspection analysis, etc. Short-term overheat blowout of tube, its reason is run sugar.%某糖厂锅炉连续两次水冷壁管爆管,通过对爆管前的运行记录检查、爆管后锅炉内部、爆破口的形貌、爆破管的管径变化、爆破口的组织和性能变化及管内壁结垢等检验分析,属短期过热爆管,其原因是“跑糖”。

  7. Mixing Metals in the Early Universe

    CERN Document Server

    Ferrara, A; Shchekinov, Yu A; Ferrara, Andrea; Pettini, Max; Shchekinov, Yuri

    2000-01-01

    We investigate the evolution of the metallicity of the intergalactic medium (IGM) with particular emphasis on its spatial distribution. We propose that metal enrichment occurs as a two step process. First, supernova (SN) explosions eject metals into relatively small regions confined to the surroundings of star-forming galaxies. From a comprehensive treatment of blowout we show that SNae by themselves fail by more than one order of magnitude to distribute the products of stellar nucleosynthesis over volumes large enough to pollute the whole IGM to the metallicity levels observed. Thus, a additional (but as yet unknown) physical mechanism must be invoked to mix the metals on scales comparable to the mean distance between the galaxies which are most efficient pollutants. From this simple hypothesis we derive a number of testable predictions for the evolution of the IGM metallicity. Specifically, we find that: (i) the fraction of metals ejected over the star formation history of the universe is about 50% at z=0; ...

  8. On the Magnetic and Energy Characteristics of Recurrent Homologous Jets from An Emerging Flux

    CERN Document Server

    Liu, Jiajia; Erdélyi, Robertus; Liu, Rui; McIntosh, Scott W; Gou, Tingyu; Chen, Jun; Liu, Kai; Liu, Lijuan; Pan, Zonghao

    2016-01-01

    In this paper, we present the detailed analysis of recurrent homologous jets originating from an emerging negative magnetic flux at the edge of an Active Region. The observed jets show multi-thermal features. Their evolution shows high consistence with the characteristic parameters of the emerging flux, suggesting that with more free magnetic energy, the eruptions tend to be more violent, frequent and blowout-like. The average temperature, average electron number density and axial speed are found to be similar for different jets, indicating that they should have been formed by plasmas from similar origins. Statistical analysis of the jets and their footpoint region conditions reveals a strong positive relationship between the footpoint-region total 131 {\\AA} intensity enhancement and jets' length/width. Stronger linearly positive relationships also exist between the total intensity enhancement/thermal energy of the footpoint regions and jets' mass/kinetic/thermal energy, with higher cross-correlation coeffici...

  9. Droplet breakup in subsea oil releases--part 2: predictions of droplet size distributions with and without injection of chemical dispersants.

    Science.gov (United States)

    Johansen, Øistein; Brandvik, Per Johan; Farooq, Umer

    2013-08-15

    A new method for prediction of droplet size distributions from subsea oil and gas releases is presented in this paper. The method is based on experimental data obtained from oil droplet breakup experiments conducted in a new test facility at SINTEF. The facility is described in a companion paper, while this paper deals with the theoretical basis for the model and the empirical correlations used to derive the model parameters from the available data from the test facility. A major issue dealt with in this paper is the basis for extrapolation of the data to full scale (blowout) conditions. Possible contribution from factors such as buoyancy flux and gas void fraction are discussed and evaluated based on results from the DeepSpill field experiment.

  10. Coronal Sources of Impulsive Fe-Rich Solar Energetic Particle Events

    CERN Document Server

    Kahler, Stephen; Cliver, Edward

    2015-01-01

    We review recent work on 111 Fe-rich impulsive solar energetic ($\\sim$ 3 MeV/nuc) particle (SEP) events observed from 1994 to 2013. Strong elemental abundance enhancements scale with A/Q, the ion mass-to-charge ratio, as (A/Q)$^{\\alpha}$, where 2 $$ 10 MK. Only a small number of SEP events slightly outside this temperature range were found in an expanded search of impulsive Fe-rich events. Event characteristics are similar for events isolated in time and those occurring in clusters. The current challenge is to determine the solar sources of the Fe-rich events. Ambient coronal regions in the 2.5--3.2 MK range are broadly distributed both in and outside active regions. We explore the possibility of acceleration from thermal plasmas at reconnecting current sheets in the context of observed standard and blowout jets. Recent current sheet reconnection modelling provides a basis for the A/Q enhancements.

  11. Geological Characteristics and Exploration Potential of Dongying Sag

    Institute of Scientific and Technical Information of China (English)

    Zheng Herong

    1997-01-01

    @@ Dongying Sag is an area where the country's earlier large-scale exploration campaign was conducted in Bohai Bay Basin in 1961. An 8.1 t/d of commercial oil flow was discovered in Well Hua-8. Well blowout happened in Well Ying-2 on Sept. 23, 1962.After the drilling, the tested production was 555 t/d with a 15 mm choke, which was the highest single well daily production in China at that time. Since then, stepout exploration has been carried out in Dongying Sag. With 32years of unremitting efforts, 32 oil/gas fields with a 870-square-kilemeter of proved oil-bearing area and 1.75 billion tons of original oil in place, as well as 100-square-kilemeter of proved gas-bearing area and 13.48 billion m3 of gas in place have been discovered in Dongying Sag.

  12. Compact tunable Compton x-ray source from laser-plasma accelerator and plasma mirror

    CERN Document Server

    Tsai, Hai-En; Shaw, Joseph; Li, Zhengyan; Arefiev, Alexey V; Zhang, Xi; Zgadzaj, Rafal; Henderson, Watson; Khudik, V; Shvets, G; Downer, M C

    2014-01-01

    We present results of the first tunable Compton backscattering (CBS) x-ray source that is based on the easily aligned combination of a laser-plasma accelerator (LPA) and a plasma mirror (PM). The LPA is driven in the blowout regime by 30 TW, 30 fs laser pulses, and produces high-quality, tunable, quasi-monoenergetic electron beams. A thin plastic film near the gas jet exit efficiently retro-reflects the LPA driving pulse with relativistic intensity into oncoming electrons to produce $2\\times10^{7}$ CBS x-ray photons per shot with 10-20 mrad angular divergence and 50 % (FWHM) energy spread without detectable bremsstrahlung background. The x-ray central energy is tuned from 75 KeV to 200 KeV by tuning the LPA e-beam central energy. Particle-in-cell simulations of the LPA, the drive pulse/PM interaction and CBS agree well with measurements.

  13. Electron Acceleration in Wakefield and Supra-Bubble Regimes by Ultraintense Laser with Asvmmetric Pulse*

    Institute of Scientific and Technical Information of China (English)

    BAKE Maimaitiaili; XIE Bai-Song; DULAT Sayipjamal; AIMIDULA Aimierding

    2011-01-01

    Electron acceleration in plasma driven by circular polarized ultraintense laser with asymmetric pulse are investigated analytically and numerically in terms of oscillation-center Hamiltonian formalism.Studies include wakefield acceleration, which dominates in blow-out or bubble regime and snow-plow acceleration which dominates in supra-bubble regime.By a comparison with each other it is found that snow-plow acceleration has lower acceleration capability.In wakefield acceleration, there exists an obvious optimum pulse asymmetry or/and pulse lengths that leads to the high net energy gain while in snow-plow acceleration it is insensitive to the pulse lengths.Power and linear scaling laws for wakefield and snow-plow acceleration respetively are observed from the net energy gain depending on laser field amplitude.Moreover, there exists also an upper and lower limit on plasma density for an effective acceleration in both of regimes.

  14. Dynamics of boundary layer electrons around a laser wakefield bubble

    Science.gov (United States)

    Luo, J.; Chen, M.; Zhang, G.-B.; Yuan, T.; Yu, J.-Y.; Shen, Z.-C.; Yu, L.-L.; Weng, S.-M.; Schroeder, C. B.; Esarey, E.

    2016-10-01

    The dynamics of electrons forming the boundary layer of a highly nonlinear laser wakefield driven in the so called bubble or blowout regime is investigated using particle-in-cell simulations. It is shown that when the driver pulse intensity increases or the focal spot size decreases, a significant amount of electrons initially pushed by the laser pulse can detach from the bubble structure at its tail, middle, or front and form particular classes of waves locally with high densities, referred to as the tail wave, lateral wave, and bow wave. The tail wave and bow wave correspond to real electron trajectories, while the lateral wave does not. The detached electrons can be ejected transversely, containing considerable energy, and reducing the efficiency of the laser wakefield accelerator. Some of the transversely emitted electrons may obtain MeV level energy. These electrons can be used for wake evolution diagnosis and producing high frequency radiation.

  15. Role of Direct Laser Acceleration of Electrons in a Laser Wakefield Accelerator with Ionization Injection

    Science.gov (United States)

    Shaw, J. L.; Lemos, N.; Amorim, L. D.; Vafaei-Najafabadi, N.; Marsh, K. A.; Tsung, F. S.; Mori, W. B.; Joshi, C.

    2017-02-01

    We show the first experimental demonstration that electrons being accelerated in a laser wakefield accelerator operating in the forced or blowout regimes gain significant energy from both the direct laser acceleration (DLA) and the laser wakefield acceleration mechanisms. Supporting full-scale 3D particle-in-cell simulations elucidate the role of the DLA of electrons in a laser wakefield accelerator when ionization injection of electrons is employed. An explanation is given for how electrons can maintain the DLA resonance condition in a laser wakefield accelerator despite the evolving properties of both the drive laser and the electrons. The produced electron beams exhibit characteristic features that are indicative of DLA as an additional acceleration mechanism.

  16. Electron beam manipulation, injection and acceleration in plasma wakefield accelerators by optically generated plasma density spikes

    Energy Technology Data Exchange (ETDEWEB)

    Wittig, Georg; Karger, Oliver S.; Knetsch, Alexander [Institute of Experimental Physics, University of Hamburg, 22761 Hamburg (Germany); Xi, Yunfeng; Deng, Aihua; Rosenzweig, James B. [Particle Beam Physics Laboratory, UCLA, Los Angeles, CA 90095 (United States); Bruhwiler, David L. [RadiaSoft LLC, Boulder, CO 80304 (United States); RadiaBeam Technologies LLC (United States); Smith, Jonathan [Tech-X UK Ltd, Daresbury, Cheshire WA4 4FS (United Kingdom); Sheng, Zheng-Ming; Jaroszynski, Dino A.; Manahan, Grace G. [Physics Department, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Hidding, Bernhard [Institute of Experimental Physics, University of Hamburg, 22761 Hamburg (Germany); Physics Department, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom)

    2016-09-01

    We discuss considerations regarding a novel and robust scheme for optically triggered electron bunch generation in plasma wakefield accelerators [1]. In this technique, a transversely propagating focused laser pulse ignites a quasi-stationary plasma column before the arrival of the plasma wake. This localized plasma density enhancement or optical “plasma torch” distorts the blowout during the arrival of the electron drive bunch and modifies the electron trajectories, resulting in controlled injection. By changing the gas density, and the laser pulse parameters such as beam waist and intensity, and by moving the focal point of the laser pulse, the shape of the plasma torch, and therefore the generated trailing beam, can be tuned easily. The proposed method is much more flexible and faster in generating gas density transitions when compared to hydrodynamics-based methods, and it accommodates experimentalists needs as it is a purely optical process and straightforward to implement.

  17. Linear to non linear analysis for positron acceleration in plasma hollow channel wakefields

    Science.gov (United States)

    Amorim, Ligia Diana; An, Weiming; Mori, Warren B.; Vieira, Jorge

    2016-10-01

    Plasma wakefield accelerators are promising candidates for future generation compact accelerators. The standard regime of operation, non-linear or blowout regime, is reached when a particle bunch space charge or laser pulse ponderomotive force radially expels plasma electrons forming a bucket of ions that defocus positron bunches, thus preventing their acceleration. To avoid defocusing, hollow plasma channels have been considered. The corresponding wakefields have been examined in the linear and non-linear excitation regimes for electrons. It is therefore important to extend the theory for positron acceleration, particularly in the nonlinear regime where the wakefields strongly differ. In this work we explore the wakefield structure, examine the differences between the electron and positron beam cases, and explore positron acceleration in nonlinear regimes. We support our findings with multi-dimensional particle-in-cell simulations performed with OSIRIS and quasi-3D and QuickPIC.

  18. Natural gas production by fracking in Germany; Erdgasgewinnung durch Fracking in Deutschland

    Energy Technology Data Exchange (ETDEWEB)

    Muehlendahl, Karl Ernst v.; Otto, Matthias [Kinderumwelt gGmbH der Deutschen Akademie fuer Kinder- und Jugendmedizin, Osnabrueck (Germany)

    2012-11-01

    ExxonMobil is performing exploration tests in Lower Saxony concerning unconventional sources for natural gas production using hydraulic fracturing. The contribution is dealing with environmental policy related questions that affect public health and should be part of the information of physicians. The contribution covers information on the issues hydraulic fracturing, water consumption and application of chemicals, drilling accidents - blow-out, energy balance, legal questions, summarizing recommendations of neutral expert team, higher-ranking points of view with respect to environmental protection and compatibility. [German] Bei umweltpolitischen Fragen, die auch die Gesundheit der Bevoelkerung tangieren, sollten aerzte informiert sein, um ggf. sachkundig mitsprechen zu koennen. Der Bereitstellung einer notwendigen Basisinformation zu dem Thema Fracking, das in betroffenen Gebieten in Niedersachsen und im Muensterland viel diskutiert wird, dienen die nachfolgenden Ausfuehrungen.

  19. Well safety in Brazil; Seguranca de poco no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Otto L.A.; Sotomayor, Gabriel P.G.; Lage, Antonio C.M.; Scaringi Filho, Orlando; Martins, Francisco S.B. [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2004-07-01

    This article presents and discusses the actions taken in Brazil, in order to make drilling, completion and intervention operations safer. The implementation of these actions resulted in a reduction of the number of blowouts in the Country. They can be grouped into four categories: training and certification in well control of all personnel directly involved in drilling, completion and intervention operations (so far, more than 3800 well control certificates have been issued since the beginning of the certification program in 1993); rig inspections of the well control equipment and procedures and follow-up of the well control drills and rig crew certification; development of a program for writing regulations for several well control aspects such as design and operational procedures, equipment requirements, and practical recommendations for well control operations; and well control research projects specially those focused on deep waters. (author)

  20. Evidence for high-energy and low-emittance electron beams using ionization injection of charge in a plasma wakefield accelerator

    CERN Document Server

    Vafaei-Najafabadi, N; Clayton, C E; Joshi, C; Marsh, K A; Mori, W B; Welch, E C; Lu, W; Adli, E; Allen, J; Clarke, C I; Corde, S; Frederico, J; Gessner, S J; Green, S Z; Hogan, M J; Litos, M D; Yakimenko, V

    2015-01-01

    Ionization injection in a plasma wakefield accelerator was investigated experimentally using two lithium plasma sources of different lengths. The ionization of the helium gas, used to confine the lithium, injects electrons in the wake. After acceleration, these injected electrons were observed as a distinct group from the drive beam on the energy spectrometer. They typically have a charge of tens of pC, an energy spread of a few GeV, and a maximum energy of up to 30 GeV. The emittance of this group of electrons can be many times smaller than the initial emittance of the drive beam. The energy scaling for the trapped charge from one plasma length to the other is consistent with the blowout theory of the plasma wakefield.

  1. Deep-sea oil plume enriches psychrophilic oil-degrading bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Hazen, T.C.; Dubinsky, E.A.; DeSantis, T.Z.; Andersen, G.L.; Piceno, Y.M.; Singh, N.; Jansson, J.K.; Probst, A.; Borglin, S.E.; Fortney, J.L.; Stringfellow, W.T.; Bill, M.; Conrad, M.S.; Tom, L.M.; Chavarria, K.L.; Alusi, T.R.; Lamendella, R.; Joyner, D.C.; Spier, C.; Auer, M.; Zemla, M.L.; Chakraborty, R.; Sonnenthal, E.L.; D' haeseleer, P.; Holman, H.-Y. N.; Osman, S.; Lu, Z.; Van Nostrand, J.D.; Deng, Y.; Zhou, J.; Mason, O.U.

    2010-09-01

    The biological effects and expected fate of the vast amount of oil in the Gulf of Mexico from the Deepwater Horizon blowout are unknown owing to the depth and magnitude of this event. Here, we report that the dispersed hydrocarbon plume stimulated deep-sea indigenous {gamma}-Proteobacteria that are closely related to known petroleum degraders. Hydrocarbon-degrading genes coincided with the concentration of various oil contaminants. Changes in hydrocarbon composition with distance from the source and incubation experiments with environmental isolates demonstrated faster-than-expected hydrocarbon biodegradation rates at 5 C. Based on these results, the potential exists for intrinsic bioremediation of the oil plume in the deep-water column without substantial oxygen drawdown.

  2. Non-technical skills: enhancing safety in operating theatres (and drilling rigs).

    Science.gov (United States)

    Flin, Rhona

    2014-03-01

    On April 20th 2010, a large Transocean drilling rig called the Deepwater Horizon was operating in the Gulf of Mexico to drill the Macondo well, for the oil company BP. The job was six weeks behind schedule and $58 million over budget and had not been without difficulty: it was a high pressure well, 2.5 miles below the seabed. At 5.45 am, the Halliburton cementing engineer sent an email to say: 'We have completed the job and it went well'. At 9.43 pm, 16 hours later, there was a release of hydrocarbons into the well bore and the drilling rig experienced a catastrophic blowout as the high pressure oil and gas escaped onto the rig and into the ocean. The resulting explosions and fire killed 11 of the crew of 126, injured many more and created an enormous oil spill across the Gulf.

  3. In search of the state-of-the art in estimating geopressures; Buscando o estado-da-arte nas estimativas de geopressoes

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Luiz Alberto [PETROBRAS, Rio de Janeiro, RJ (Brazil). E e P Engenharia de Producao. Gerencia de Perfuracoes e Operacoes Especiais], e-mail: luizrocha@petrobras.com.br; Azevedo, Cecilia Toledo de [Pontificia Univ. Catolica do Rio de Janeiro (PUC/Rio), RJ (Brazil)], e-mail: ctazevedo@gmail.com

    2006-06-15

    Problems related to geopressures are well known in the oil industry. They range from minor well instability problems to major blowouts that result in the drilling unit total loss. Such events led many operators to invest large amounts of money to develop methods capable of improving geopressure estimates. The objective of this study is to describe the efforts endeavored by PETROBRAS in order to enhance such estimates. This paper has been subdivided into basic concepts and historical cases. Basic concepts have as a goal to provide the reader with a knowledge on geopressure theory and historical cases present some relevant examples that include: zones with high pressures and high temperatures; geopressure prediction and real time monitoring work; regions under the influence of more than one mechanism that creates abnormal pressures; problems related to the collapse gradient in directional wells drilled in great water depths; area where high overpressure are found in the Gulf of Mexico. (author)

  4. Modelling the long-term evolution of worst-case Arctic oil spills.

    Science.gov (United States)

    Blanken, Hauke; Tremblay, Louis Bruno; Gaskin, Susan; Slavin, Alexander

    2017-03-15

    We present worst-case assessments of contamination in sea ice and surface waters resulting from hypothetical well blowout oil spills at ten sites in the Arctic Ocean basin. Spill extents are estimated by considering Eulerian passive tracers in the surface ocean of the MITgcm (a hydrostatic, coupled ice-ocean model). Oil in sea ice, and contamination resulting from melting of oiled ice, is tracked using an offline Lagrangian scheme. Spills are initialized on November 1st 1980-2010 and tracked for one year. An average spill was transported 1100km and potentially affected 1.1 million km(2). The direction and magnitude of simulated oil trajectories are consistent with known large-scale current and sea ice circulation patterns, and trajectories frequently cross international boundaries. The simulated trajectories of oil in sea ice match observed ice drift trajectories well. During the winter oil transport by drifting sea ice is more significant than transport with surface currents.

  5. Idealized gas turbine combustor for performance research and validation of large eddy simulations.

    Science.gov (United States)

    Williams, Timothy C; Schefer, Robert W; Oefelein, Joseph C; Shaddix, Christopher R

    2007-03-01

    This paper details the design of a premixed, swirl-stabilized combustor that was designed and built for the express purpose of obtaining validation-quality data for the development of large eddy simulations (LES) of gas turbine combustors. The combustor features nonambiguous boundary conditions, a geometrically simple design that retains the essential fluid dynamics and thermochemical processes that occur in actual gas turbine combustors, and unrestrictive access for laser and optical diagnostic measurements. After discussing the design detail, a preliminary investigation of the performance and operating envelope of the combustor is presented. With the combustor operating on premixed methane/air, both the equivalence ratio and the inlet velocity were systematically varied and the flame structure was recorded via digital photography. Interesting lean flame blowout and resonance characteristics were observed. In addition, the combustor exhibited a large region of stable, acoustically clean combustion that is suitable for preliminary validation of LES models.

  6. Pelagic tar off Georgia and Florida in relation to physical processes

    Energy Technology Data Exchange (ETDEWEB)

    Cordes, C.; Atkinson, L.; Lee, R.; Blanton, J.

    1980-01-01

    Following the Ixtoc I oil rig blowout in Campeche Bay we hypothesized that resulting tarballs should eventually appear in the Gulf Stream off Georgia and that because of dynamic barriers in the innershelf little would reach near-shore areas. To test these hypotheses, surface tows to collect floating tar were taken off the coasts of Georgia and Florida in October and December 1979. No tar was found within 40 km of the shore. All samples more than 40 km offshore contained some tar. The mean concentration was 0.82 mg m/sup -2/ with a range of 0.01 to 5.6 mg m/sup -2/. Closely spaced sampling showed extreme variation but trends were consistent. Perylene was the most abundant compound in the tarballs.

  7. Linking irreplaceable landforms in a self-organizing landscape to sensitivity of population vital rates for an ecological specialist.

    Science.gov (United States)

    Ryberg, Wade A; Hill, Michael T; Painter, Charles W; Fitzgerald, Lee A

    2015-06-01

    Irreplaceable, self-organizing landforms and the endemic and ecologically specialized biodiversity they support are threatened globally by anthropogenic disturbances. Although the outcome of disrupting landforms is somewhat understood, little information exists that documents population consequences of landform disturbance on endemic biodiversity. Conservation strategies for species dependent upon landforms have been difficult to devise because they require understanding complex feedbacks that create and maintain landforms and the consequences of landform configuration on demography of species. We characterized and quantified links between landform configuration and demography of an ecological specialist, the dunes sagebrush lizard (Sceloporus arenicolus), which occurs only in blowouts (i.e., wind-blown sandy depressions) of Shinnery oak (Quercus havardii) sand-dune landforms. We used matrix models to estimate vital rates from a multisite mark-recapture study of 6 populations occupying landforms with different spatial configurations. Sensitivity and elasticity analyses demonstrated demographic rates among populations varied in sensitivity to different landform configurations. Specifically, significant relationships between blowout shape complexity and vital rate elasticities suggested direct links between S. arenicolus demography and amount of edge in Shinnery oak sand-dune landforms. These landforms are irreplaceable, based on permanent transition of disturbed areas to alternative grassland ecosystem states. Additionally, complex feedbacks between wind, sand, and Shinnery oak maintain this landform, indicating restoration through land management practices is unlikely. Our findings that S. arenicolus population dynamics depended on landform configuration suggest that failure to consider processes of landform organization and their effects on species' population dynamics may lead to incorrect inferences about threats to endemic species and ineffective habitat

  8. Metagenomic analysis and metabolite profiling of deep-sea sediments from the Gulf of Mexico following the Deepwater Horizon oil spill

    Directory of Open Access Journals (Sweden)

    Nikole Elizabeth Kimes

    2013-03-01

    Full Text Available Marine subsurface environments, such as deep-sea sediments, house abundant and diverse microbial communities that are believed to influence large-scale geochemical processes. These processes include the biotransformation and mineralization of numerous petroleum constituents. Thus, microbial communities in the Gulf of Mexico are thought to be responsible for the intrinsic bioremediation of crude oil released by the Deepwater Horizon (DWH oil spill. While hydrocarbon contamination is known to enrich for aerobic, oil-degrading bacteria in deep-seawater habitats, relatively little is known about the response of communities in deep-sea sediments, where low oxygen levels may hinder such a response. Here, we examined the hypothesis that increased hydrocarbon exposure results in an altered sediment microbial community structure that reflects the prospects for oil biodegradation under the prevailing conditions. We explore this hypothesis using metagenomic analysis and metabolite profiling of deep-sea sediment samples following the DWH oil spill. The presence of aerobic microbial communities and associated functional genes was consistent among all samples, whereas, a greater number of Deltaproteobacteria and anaerobic functional genes were found in sediments closest to the DWH blowout site. Metabolite profiling also revealed a greater number of putative metabolites in sediments surrounding the blowout zone relative to a background site located 127 km away. The mass spectral analysis of the putative metabolites revealed that alkylsuccinates remained below detection levels, but a homologous series of benzylsuccinates (with carbon chain lengths from 5 to 10 could be detected. Our findings suggest that increased exposure to hydrocarbons enriches for Deltaproteobacteria, which are known to be capable of anaerobic hydrocarbon metabolism. We also provide evidence for an active microbial community metabolizing aromatic hydrocarbons in deep-sea sediments of the

  9. 2009 review of the Deep Panuke Environmental Effects Monitoring Plan

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    The Oceans, Habitat and Species at Risk branch of the Department of Fisheries and Oceans Canada requested an update to the Environmental Management Plan for the construction of the Deep Panuke Project. Specifically, it requested expert advice on the 2009-2010 Drilling Environmental Protection Plan/Environmental Effects Monitoring Plan (EPP/EEMP), which outlines the measures that EnCana proposes take to avoid or minimize the effects of drilling in the marine environment. Although the proposed approach was deemed to be sufficient, the EPP/EEMP did not make reference to the potential effects of noise on marine species. The jack-up rig mobile offshore production unit that is proposed for well drilling and well re-entries was considered to produce lower noise levels than drillships and semi submersibles. It was concluded that jack up drilling at Deep Panuke would not likely require special noise mitigation measures, but more extensive measurement and documentation of acoustic noise levels around active rigs is recommended. The risk of well blowout or collapse was deemed low. Should such an event occur, the impact of the released hydrocarbon condensate would depend on the rate and duration of the release. Under typical conditions, the proponent's models reasonably show the blowout discharge drifting away from Sable Island. However, there is a very low risk that certain weather conditions would result in an oil spill reaching Sable Island. The EPP/EEMP does not address species at risk in any way, and mitigation measures are required and should be detailed in the monitoring plan. It was concluded that the proposed EPP/EEMP is sufficient in many areas, but since most mitigation measures are based on theoretical considerations alone, a plan for field monitoring at the drilling site is needed. 3 refs.

  10. The Dimensions of the Orbital Cavity Based on High-Resolution Computed Tomography of Human Cadavers.

    Science.gov (United States)

    Felding, Ulrik Ascanius; Bloch, Sune Land; Buchwald, Christian von

    2016-06-01

    Blow-out fractures affect the volume and surface area of the orbital cavity. Estimation of these values after the trauma may help in deciding whether or not a patient is a candidate for surgery. Recent studies have provided estimates of orbital volume and area of bone defect, and correlated them with the degree of enophthalmos. However, a large degree of biological variation between individuals may preclude such absolute values from being successful indicators for surgery.Stereological methods have been used to estimate orbital cavity volume in a few studies, but to date these have not been used for surface area. To authors' knowledge, this study is the first to have measured the entire surface area of the orbital cavity.The volume and surface area of the orbital cavity were estimated in computed tomography scans of 11 human cadavers using unbiased stereological sampling techniques. The mean (± SD) total volume and total surface area of the orbital cavities was 24.27 ± 3.88 cm and 32.47 ± 2.96 cm, respectively. There was no significant difference in volume (P = 0.315) or surface area (P = 0.566) between the 2 orbital cavities.The stereological technique proved to be a robust and unbiased method that may be used as a gold standard for comparison with automated computer software. Future imaging studies in blow-out fracture patients may be based on individual and relative calculation involving both herniated volume and fractured surface area in relation to the total volume and surface area of the uninjured orbital cavity.

  11. THE ENVIRONMENTAL LEGACY OF THE IXTOC-I OIL SPILL IN CAMPECHE SOUND, SOUTHWESTERN GULF OF MEXICO

    Directory of Open Access Journals (Sweden)

    Luis Arturo Soto

    2014-11-01

    Full Text Available The southwestern Gulf of Mexico constitutes an important subsystem within a Large Marine Ecosystem. Due to its high biodiversity, living resources and energy resources, this region is strategic in the national plans for social and economic development of Mexico. The discovery of fossil fuel reserves in the seabed of Campeche Sound in the 1970s promoted the rapid expansion of the national oil industry in offshore waters. Unfortunately, the accidental blowout of the most productive well (Ixtoc-I in June of 1979, caused the first–world massive oil spill in a tropical marine environment. More than 3.4 million of barrels of crude oil were liberated in an ecosystem formerly renowned for its pristine conditions. In the aftermath of this dreadful accident, an immediate concern emerged not only for the oil acute effects but also for the long-term environmental consequences derived from the residual hydrocarbon compounds accumulated in coastal environments of the southern Gulf of Mexico. The attempts to assess the magnitude of the environmental damage were strongly precluded by the lack of pre-spill information. Natural variability in the ecosystem and oil weathering-factors contributed to attenuate the acute pollution effects that lasted nine months. However, the post-spill environmental alterations caused by the Ixtoc-I blowout still remain unanswered. The sinking of the Deepwater Horizon oil platform in the deep-waters of the northern Gulf of Mexico, in 2010 rekindled our concern for the great risk involved for human lives and the health of shallow and deep sea habitats. The authors of this contribution offer their views on this environmental riddle from their own perspective as direct witnesses of the Ixtoc-I environmental tragedy.

  12. Dark-matter haloes and the M-σ relation for supermassive black holes

    Science.gov (United States)

    Larkin, Adam C.; McLaughlin, Dean E.

    2016-10-01

    We develop models of two-component spherical galaxies to establish scaling relations linking the properties of spheroids at z = 0 (total stellar masses, effective radii Re and velocity dispersions within Re) to the properties of their dark-matter haloes at both z = 0 and higher redshifts. Our main motivation is the widely accepted idea that the accretion-driven growth of supermassive black holes (SMBHs) in protogalaxies is limited by quasar-mode feedback and gas blow-out. The SMBH masses, MBH, should then be connected to the dark-matter potential wells at the redshift zqso of the blow-out. We specifically consider the example of a power-law dependence on the maximum circular speed in a protogalactic dark-matter halo: M_{BH}∝ V^4_{d,pk}, as could be expected if quasar-mode feedback were momentum-driven. For haloes with a given Vd,pk at a given zqso ≥ 0, our model scaling relations give a typical stellar velocity dispersion σap(Re) at z = 0. Thus, they transform a theoretical MBH-Vd,pk relation into a prediction for an observable MBH-σap(Re) relation. We find the latter to be distinctly non-linear in log-log space. Its shape depends on the generic redshift evolution of haloes in a Λ cold dark matter cosmology and the systematic variation of stellar-to-dark matter mass fraction at z = 0, in addition to any assumptions about the physics underlying the MBH-Vd,pk relation. Despite some clear limitations of the form we use for MBH versus Vd,pk, and even though we do not include any SMBH growth through dry mergers at low redshift, our results for MBH-σap(Re) compare well to data for local early types if we take zqso ˜ 2-4.

  13. Review of flow rate estimates of the Deepwater Horizon oil spill

    Science.gov (United States)

    McNutt, Marcia K.; Camilli, Rich; Crone, Timothy J.; Guthrie, George D.; Hsieh, Paul A.; Ryerson, Thomas B.; Savas, Omer; Shaffer, Frank

    2012-01-01

    The unprecedented nature of the Deepwater Horizon oil spill required the application of research methods to estimate the rate at which oil was escaping from the well in the deep sea, its disposition after it entered the ocean, and total reservoir depletion. Here, we review what advances were made in scientific understanding of quantification of flow rates during deep sea oil well blowouts. We assess the degree to which a consensus was reached on the flow rate of the well by comparing in situ observations of the leaking well with a time-dependent flow rate model derived from pressure readings taken after the Macondo well was shut in for the well integrity test. Model simulations also proved valuable for predicting the effect of partial deployment of the blowout preventer rams on flow rate. Taken together, the scientific analyses support flow rates in the range of ~50,000–70,000 barrels/d, perhaps modestly decreasing over the duration of the oil spill, for a total release of ~5.0 million barrels of oil, not accounting for BP's collection effort. By quantifying the amount of oil at different locations (wellhead, ocean surface, and atmosphere), we conclude that just over 2 million barrels of oil (after accounting for containment) and all of the released methane remained in the deep sea. By better understanding the fate of the hydrocarbons, the total discharge can be partitioned into separate components that pose threats to deep sea vs. coastal ecosystems, allowing responders in future events to scale their actions accordingly.

  14. ON THE UNUSUAL GAS COMPOSITION IN THE {beta} PICTORIS DEBRIS DISK

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Ji-Wei; Wu, Yanqin [Department of Astronomy and Astrophysics, University of Toronto, Toronto, ON M5S 3H4 (Canada); Brandeker, Alexis, E-mail: jwxie@astro.utoronto.ca, E-mail: wu@astro.utoronto.ca, E-mail: alexis@astro.su.se [Department of Astronomy, Stockholm University, SE-106 91 Stockholm (Sweden)

    2013-01-10

    The metallic gas associated with the {beta} Pic debris disk is not believed to be primordial, but arises from the destruction of dust grains. Recent observations have shown that carbon and oxygen in this gas are exceptionally overabundant compared to other elements, by some 400 times. We study the origin of this enrichment under two opposing hypotheses: preferential production, where the gas is produced with the observed unusual abundance (as may happen if gas is produced by photodesorption from C/O-rich icy grains), and preferential depletion, where the gas evolves to the observed state from an original solar abundance (if outgassing occurs under high-speed collisions) under a number of dynamical processes. We include in our study the following processes: radiative blowout of metallic elements, dynamical coupling between different species, and viscous accretion onto the star. We find that, if gas viscosity is sufficiently low (the conventional {alpha} parameter {approx}< 10{sup -3}), differential blowout dominates. While gas accumulates gradually in the disks, metallic elements subject to strong radiation forces, such as Na and Fe, deplete more quickly than C and O, naturally leading to the observed overabundance of C and O. On the other hand, if gas viscosity is high ({alpha} {approx}> 10{sup -1}, as expected for this largely ionized disk), gas is continuously produced and viscously accreted toward the star. This removal process does not discriminate between elements so the observed overabundance of C and O has to be explained by a preferential production that strongly favors C and O to other metallic elements. One such candidate is photodesorption off the grains. We compare our calculation against all observed elements ({approx}10) in the gas disk and find a mild preference for the second scenario, based on the abundance of Si alone. If true, {beta} Pic should still be accreting at an observable rate, well after its primordial disk has disappeared.

  15. Metagenomic analysis and metabolite profiling of deep-sea sediments from the Gulf of Mexico following the Deepwater Horizon oil spill.

    Science.gov (United States)

    Kimes, Nikole E; Callaghan, Amy V; Aktas, Deniz F; Smith, Whitney L; Sunner, Jan; Golding, Bernardt; Drozdowska, Marta; Hazen, Terry C; Suflita, Joseph M; Morris, Pamela J

    2013-01-01

    Marine subsurface environments such as deep-sea sediments, house abundant and diverse microbial communities that are believed to influence large-scale geochemical processes. These processes include the biotransformation and mineralization of numerous petroleum constituents. Thus, microbial communities in the Gulf of Mexico are thought to be responsible for the intrinsic bioremediation of crude oil released by the Deepwater Horizon (DWH) oil spill. While hydrocarbon contamination is known to enrich for aerobic, oil-degrading bacteria in deep-seawater habitats, relatively little is known about the response of communities in deep-sea sediments, where low oxygen levels may hinder such a response. Here, we examined the hypothesis that increased hydrocarbon exposure results in an altered sediment microbial community structure that reflects the prospects for oil biodegradation under the prevailing conditions. We explore this hypothesis using metagenomic analysis and metabolite profiling of deep-sea sediment samples following the DWH oil spill. The presence of aerobic microbial communities and associated functional genes was consistent among all samples, whereas, a greater number of Deltaproteobacteria and anaerobic functional genes were found in sediments closest to the DWH blowout site. Metabolite profiling also revealed a greater number of putative metabolites in sediments surrounding the blowout zone relative to a background site located 127 km away. The mass spectral analysis of the putative metabolites revealed that alkylsuccinates remained below detection levels, but a homologous series of benzylsuccinates (with carbon chain lengths from 5 to 10) could be detected. Our findings suggest that increased exposure to hydrocarbons enriches for Deltaproteobacteria, which are known to be capable of anaerobic hydrocarbon metabolism. We also provide evidence for an active microbial community metabolizing aromatic hydrocarbons in deep-sea sediments of the Gulf of Mexico.

  16. Spatially resolved imaging of the two-component η Crv debris disk with Herschel

    Energy Technology Data Exchange (ETDEWEB)

    Duchêne, G.; Arriaga, P.; Kalas, P. [Astronomy Department, University of California, Berkeley, CA 94720 (United States); Wyatt, M.; Kennedy, G. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 0HA (United Kingdom); Sibthorpe, B. [SRON Netherlands Institute for Space Research, P.O. Box 800, 9700 AV Groningen (Netherlands); Lisse, C. [JHU-APL, 11100 Johns Hopkins Road, Laurel, MD 20723 (United States); Holland, W. [UK Astronomy Technology Centre, Royal Observatory Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Wisniewski, J. [H.L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W. Brooks St., Norman, OK 73019 (United States); Clampin, M. [NASA Goddard Space Flight Center, Code 681, Greenbelt, MD 20771 (United States); Pinte, C. [UMI-FCA, CNRS/INSU, France (UMI 3386) (France); Wilner, D. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Booth, M. [Instituto de Astrofísica, Pontificia Universidad Católica de Chile, Vicuña Mackenna 4860, 7820436 Macul, Santiago (Chile); Horner, J. [School of Physics, University of New South Wales, Sydney, NSW 2052 (Australia); Matthews, B. [National Research Council of Canada Herzberg Astronomy and Astrophysics, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Greaves, J. [SUPA, School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS (United Kingdom)

    2014-04-01

    We present far-infrared and submillimeter images of the η Crv debris disk system obtained with Herschel and SCUBA-2, as well as Hubble Space Telescope visible and near-infrared coronagraphic images. In the 70 μm Herschel image, we clearly separate the thermal emission from the warm and cold belts in the system, find no evidence for a putative dust population located between them, and precisely determine the geometry of the outer belt. We also find marginal evidence for azimuthal asymmetries and a global offset of the outer debris ring relative to the central star. Finally, we place stringent upper limits on the scattered light surface brightness of the outer ring. Using radiative transfer modeling, we find that it is impossible to account for all observed properties of the system under the assumption that both rings contain dust populations with the same properties. While the outer belt is in reasonable agreement with the expectations of steady-state collisional cascade models, albeit with a minimum grain size that is four times larger than the blow-out size, the inner belt appears to contain copious amounts of small dust grains, possibly below the blow-out size. This suggests that the inner belt cannot result from a simple transport of grains from the outer belt and rather supports a more violent phenomenon as its origin. We also find that the emission from the inner belt has not declined over three decades, a much longer timescale than its dynamical timescale, which indicates that the belt is efficiently replenished.

  17. Simulation analysis of environmental risk accident and management of high-sulfur gas field development in complex terrain

    Institute of Scientific and Technical Information of China (English)

    Xiao WANG; Fanghua HAO; Xuan ZHANG; Wen SUN; Hongguang CHENG

    2008-01-01

    Environmental risk of high sulfur gas field exploitation has become one of the hot spots of envir-onmental management studies. Severe gas H2S blowout accidents in recent years have shown that poor under-standing and estimates of the poisonous gas movement could lead to dangerous evacuation delays. It is important to evaluate the real concentration of H2S, especially in complex terrain. Traditional experiential models are not valid in the case of rough terrain, especially in low-lying areas where the gas accumulates. This study, using high sulfur content gas field of Sichuan "Pu Guang gas field" as study object and adopting objective diagnosis of wind field of land following coordinate three dimensions, applied Lagrangian Puff Model and breaking up tech-nique of puffs to simulate the H2S diffusion condition of blowout accidents produced in the high sulfur content gas field of complex terrain area. The results showed that the H2S distribution did not occur mainly in low wind dir-ection, and due to the obstruction of the mountain's body, it accumulated in front of mountain on produced turn over, flowed around submitted jumping type distribution. The mountain waist near the hilltop and low hollow river valley site rapture points simulating contrast showed that the higher the rapture point, the better the diffusing con-dition of pollutant, the distribution of risk sensitive point decided piping rupture environmental risk size combining the H2S diffusion result and residential area dispersing in the study area, synthetic judge located in the high rapture point environmental risk was smaller than the low hollow point, thus it was suggested to carryout laying of lining build of equal high line of higher terrain. According to simulation results, the environmental risk management measures aimed at putting down adverse effects were worked out.

  18. Development of Cameron Style 2FZ35-35 Double-ram BOP%Cameron式2FZ35-35型双闸板防喷器研制

    Institute of Scientific and Technical Information of China (English)

    郑泳; 肖力彤; 崔凯; 唐秋林; 刘义; 杨卫星

    2011-01-01

    CNOOC,to meet user requirements,successfully developed the first oil platform in Cameron style 2FZ35-35 double-ram blowout preventer in CNPC. The blowout preventer with API Spec 6A wellhead flange and other devices,both closed and open ram with hydraulic operation assembly, ram closed manually locking ram axis method. According to API Spec 16A recommended standard,the overall strength of the liquid oil control road and tank strength,shear 5" drill pipe test,shear ram seal test,variable bore ram test (closed 31/2 "and 5" drill pipe) and path tests are satisfactory. The use of that site, it has a safe, reliable, rapid and flexible switching, structural lightweight,easy to operate.%为满足中海油用户的要求,开发了Cameron式2FZ35-35型双闸板防喷器.该防喷器采用API Spec 6A法兰与其他井口设备连接,用液压控制关闭和打开闸板总成,闸板关闭后采用手动锁紧闸板轴;整体强度、液控油路和液缸强度及剪切φ127 mm(5英寸)钻杆和剪切闸板密封试验、变径闸板试验(封隔φ88.9mm(31/2英寸)和φ127mm(5英寸)管柱)和通径试验满足API Spec 16A推荐标准.现场使用表明,具有安全可靠、开关迅速灵活、结构轻便、操作方便等特点.

  19. RESOLVING IONIZATION AND METALLICITY ON PARSEC SCALES ACROSS MRK 71 WITH HST-WFC3

    Energy Technology Data Exchange (ETDEWEB)

    James, Bethan L.; Auger, Matthew [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 0HA (United Kingdom); Aloisi, Alessandra [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Calzetti, Daniela [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Kewley, Lisa, E-mail: bjames@ast.cam.ac.uk [RSAA, Australian National University, Cotter Road, Weston Creek, ACT 2611 (Australia)

    2016-01-01

    Blue compact dwarf (BCD) galaxies in the nearby universe provide a means for studying feedback mechanisms and star formation processes in low-metallicity environments in great detail. Owing to their vicinity, these local analogs to primordial young galaxies are well suited for high-resolution studies that are unfeasible for high-redshift galaxies. Here we present Hubble Space Telescope Wide Field Camera 3 observations of one such BCD, Mrk 71, one of the most powerful local starbursts known, in the light of [O ii], He ii, Hβ, [O iii], Hα, and [S ii]. At D ≃ 3.44 Mpc, this extensive suite of emission-line images enables us to explore the chemical and physical conditions of Mrk 71 on ∼2 pc scales. We use emission-line diagnostics to distinguish ionization mechanisms on a pixel-by-pixel basis and show that despite the previously reported hypersonic gas and superbubble blowout, the gas in Mrk 71 is photoionized, with no sign of shock-excited emission. He ii emission line images are used to identify up to six Wolf-Rayet stars, three of which lie on the edge of a blowout region. Using strong-line metallicity diagnostics, we present the first “metallicity image” of a galaxy, revealing chemical inhomogeneity on scales of <50 pc. We additionally demonstrate that while chemical structure can be lost at large scales, metallicity diagnostics can break down on spatial scales smaller than an H ii region. This study highlights not only the benefits of high-resolution spatially resolved observations in assessing the effects of feedback mechanisms but also the potential limitations when employing emission-line diagnostics; these results are particularly relevant as we enter the era of extremely large telescopes.

  20. Type and distribution of aeolian goemorphology at Marqu Region of Upstream Yellow River%黄河上游玛曲地区风沙地貌的类型及其分布

    Institute of Scientific and Technical Information of China (English)

    刘虎俊; 徐先英; 王继和; 李毅; 唐进年; 柴成武; 纪永福; 李发明; 魏怀东

    2012-01-01

    玛曲草原是著名的高原牧场,也是黄河上游重要的水源涵养地,通过卫星影像分析和实地观测数据,对其风沙地貌进行分类,以期为沙化草地治理提供参考.玛曲沙化草地的风沙地貌可分为4级17类.横向沙丘(新月形沙丘)主要分布在河岸和黄河的一级或二级阶地上,单个的新月形沙丘最大高度可达12m,64%的新月形沙丘迎风坡走向与当地起沙风向一致.分布在古河道或古三角洲的流动和半流动纵向沙丘(沙垄)高度小于3 m,51%的沙垄走向与当地起沙风向相同.低山上的沙垄和沙片出现在山顶或其阳坡,地形过渡带形成风蚀坎.风蚀洼地与固定和半固定沙地伴生,60%左右的风蚀洼地横切面为不规则椭圆和马蹄形;其深度与长轴呈正比例函数关系.古(现代)沉积物提供了丰富的沙源,大风、冻融、土层的岩性差异、脆弱的植被、人类过渡干扰和微地形促成了玛曲草地沙化和风沙地貌分异.通过对风沙地貌分类、分析,提出了以保护草皮免受破坏,为防止玛曲草地沙化的主要措施.%The Marqu with rangeland area of 8. 57 × 107 hm2 is hailed as the first pasture of Asia. At present, the desertificated area is 0. 6% of the total area of the Marqu county whith 7 136. 77 hm2 of desertificated land and 3 600 hm of potential rangeland sandiflcalion, and has been expanding by the effect of climate change and people action. A field measure on eolian lariform will give reference to control the desertificated grassland of Marqu. In July and August of 2008 , we investigated the grassland of Marqu county referenced satellite image, and measured the eolian lanform, such as sand dunes and sandy blowouts and so on at plains and hills by GPS, compass and olher instruments. The surveyed result shown as follows: the eolian lanform of Marqu might be classified in 17 classes or 4 grades by reference standards of dynamic factors, dynamic bed surfaces

  1. Risk management in the oil and gas industry : integration of human, organisational and technical factors

    Energy Technology Data Exchange (ETDEWEB)

    Skogdalen, Jon Espen

    2011-07-01

    The overall objective of this thesis is to provide knowledge and tools for the major hazard risk assessment for offshore installations (and onshore plants) based on an improved understanding of the influence of organisational, human and technical (OMT) factors. This extensive objective was further described by the following sub-goals: 1. Identify and describe human and organisational barriers in risk analysis, 2. Provide knowledge regarding human, organisational and technical factors that influence safety barriers, 3. Define indicators that are suitable for the measurement of barrier performance, 4. Develop models for barrier performance reflecting human, organisational and technical factors These four sub-goals formed the basis for the more specific objectives in the articles. The Deepwater Horizon accident and Macondo blowout were important inputs for several of the articles. One important acknowledgement is that risk management of major hazards differs from managing occupational safety. Another is that managing risks in the oil and gas (O&G) industry demands a high level due to the potential severe consequences. Quantitative risk analyses/assessments (QRAs) are used for risk control in the O&G industry. An important part of the QRA process is to identify and describe barriers in risk analysis. A study of offshore QRAs (Skogdalen and Vinnem, 2011b) showed that there were large differences between the analyses regarding incorporation of human and organisational factors (HOFs). The study divided the QRAs into a four-level classification system. Level 1 QRAs did not describe or comment on HOFs at all. By contrast, relevant research projects were conducted to fulfil the requirements of level 3 analyses. At this level, there was a systematic collection of data related to HOFs. The methods for analyzing the data were systematic and documented, and the QRAs were adjusted according to the status of the HOFs. A second study of QRAs (Skogdalen and Vinnem, 2011a) revealed

  2. The Gulf of Mexico Research Initiative: Managing a Multidisciplinary Data Explosion

    Science.gov (United States)

    Howard, M. K.; Gibeaut, J. C.; Reed, D.

    2011-12-01

    On April 20, 2010 the Deepwater Horizon drilling unit located in the northeastern Gulf of Mexico, experienced a catastrophic wellhead blowout. Roughly 5 billion barrels of oil and 1 million U.S. gallons of dispersant were released near the wellhead over the next three months. Within weeks of the blowout, BP announced the Gulf of Mexico Research Initiative (GRI) and pledged 50M/yr over 10 years for independent scientific research on the spill's impact on the ecosystem. Two months after the blowout three institutions were awarded a total of 25M in fast-track grants (Louisiana State University, Northern Gulf Institute, and Florida Institute of Oceanography). Soon after the Alabama Marine Environmental Sciences Consortium and the National Institutes of Health were awarded 5M and 10M, respectively. These five institutions began to generate data almost immediately. First year grants funded 100's of researchers from nearly 100 research units. Their activities included numerical modeling, field data collection, and laboratory experiments. Measured parameters included those associated with chemical analyses of oil, gas, and dispersants, studies of bacteria, plants and animals -from phytoplankton to marsh grasses, from zooplankton to cetaceans. Studies were conducted from estuaries to the deep Gulf, from atmosphere to sediments. Parameters from physical oceanography, marine meteorology, and biogeochemistry were measured in abundance. Additionally, impact studies on human mental, physical health and businesses were made. Proposals for years 2-4 of the program were to be awarded in August 2011 supporting 4-8 research consortia. Consortia may have up to 20 named researchers. In aggregate, these studies yielded a multidisciplinary data explosion. Following the fast-track awards the GRI Administrative Unit (AU) was established and a data management activity initiated. That activity became the GRI Information and Data Cooperative (GRIIDC). "Cooperative" emphasizes the

  3. Model for straight and helical solar jets. I. Parametric studies of the magnetic field geometry

    Science.gov (United States)

    Pariat, E.; Dalmasse, K.; DeVore, C. R.; Antiochos, S. K.; Karpen, J. T.

    2015-01-01

    Context. Jets are dynamic, impulsive, well-collimated plasma events developing at many different scales and in different layers of the solar atmosphere. Aims: Jets are believed to be induced by magnetic reconnection, a process central to many astrophysical phenomena. Studying their dynamics can help us to better understand the processes acting in larger eruptive events (e.g., flares and coronal mass ejections) as well as mass, magnetic helicity, and energy transfer at all scales in the solar atmosphere. The relative simplicity of their magnetic geometry and topology, compared with larger solar active events, makes jets ideal candidates for studying the fundamental role of reconnection in energetic events. Methods: In this study, using our recently developed numerical solver ARMS, we present several parametric studies of a 3D numerical magneto-hydrodynamic model of solar-jet-like events. We studied the impact of the magnetic field inclination and photospheric field distribution on the generation and properties of two morphologically different types of solar jets, straight and helical, which can account for the observed so-called standard and blowout jets. Results: Our parametric studies validate our model of jets for different geometric properties of the magnetic configuration. We find that a helical jet is always triggered for the range of parameters we tested. This demonstrates that the 3D magnetic null-point configuration is a very robust structure for the energy storage and impulsive release characteristic of helical jets. In certain regimes determined by magnetic geometry, a straight jet precedes the onset of a helical jet. We show that the reconnection occurring during the straight-jet phase influences the triggering of the helical jet. Conclusions: Our results allow us to better understand the energization, triggering, and driving processes of straight and helical jets. Our model predicts the impulsiveness and energetics of jets in terms of the surrounding

  4. Economic Study on Hydrate Prevention Strategies of Natural Gas-Condensate Multi-Phase Flow Pipeline%天然气-凝析液混输管道水合物防控策略经济性研究

    Institute of Scientific and Technical Information of China (English)

    苗建; 郑新; 王凯; 付峻

    2016-01-01

    When the natural gas multi-phase flow pipeline is shutdown,the risk of gas hy-drate is relative high and the blowout or/and methanol, which can be used to prevent the hydrate effectively, have different costs. For the shutdown operation of the subsea pipeline of natural gas field in South China Sea with practical constraints, the amounts of gas venting and methanol injecting of different pressures levels are studied, and the cost model is pro-posed to analyze the optimal costs and related factors. The results show that there are signifi-cant differences among the costs of different strategies, and any one of the two strategies of blowout and methanol is likely to be economically optimal when they are used separately, rather than together. The best strategy depends on the amount of the assembled water in the pipeline and the methanol and natural gas prices as well.%天然气多相混输管道停输后,水合物生成风险较高,采用泄压放空、加注甲醇或两者联合使用均能有效地防控水合物生成,但其经济性不同。针对南海某气田海底管道停输工况,在充分考虑平台操作实际约束的前提下,研究了联合运用泄压与注剂措施,并提出了经济成本计算模型,分析了不同防控策略的经济性及其影响因素。结果表明,不同策略之间的经济成本差异显著,单纯注剂法和单纯放空法均有可能成为经济性最佳的水合物防控策略,而“注剂-泄压”联合策略的经济性较差;具体的最佳防控策略与管道积水量、甲醇和天然气价格密切相关。

  5. What Will Classroom Teachers Do With Shared Research Results?

    Science.gov (United States)

    Passow, M. J.; Weissel, J. K.; Cormier, M.; Newman, K. R.

    2005-12-01

    Scientists are passionate about the research problems they investigate, and wish to share their discoveries as widely as possible. Similarly, classroom teachers who are passionate about their subject can better foster student learning. One way to enhance such passions involves bringing teachers and scientists together to discuss cutting-edge discoveries and develop curricular materials based on the respective strengths of educators and investigators. Our presentation describes one example of this approach based on research about gas blowout structures offshore Virginia and North Carolina. Methane venting processes along continental margins may have important climatic, geotechnical, hazard, and resource implications. In 2000, shipboard surveys documented that large structures offshore VA-NC resulted from massive gas expulsion. Gas appears to be trapped in shelf edge deltas and stresses resulting from downslope creep is favoring its release. Scientists undertook a new expedition in 2004 to determine if there is present-day discharge of methane-rich fluids through the floors or walls of the blowouts or whether these seepage sites are relict features, and to gain insight into the origin of the vented methane. In July 2005, 12 teachers from New York and New Jersey met with the co-PIs (Weissel and Cormier), graduate student (Newman), and educational specialist (Passow) over a 2-day workshop to learn about how scientific problems are identified, how a research cruise is organized, what was learned through the measurements and analysis, and what might be possible significant impacts from such understandings. Based on what they learned, participants began development of classroom activities, Internet-based investigations, and constructed-response assessment items utilizing data and concepts from the project and other sources. The resulting curriculum units are designed for use in middle and high school chemistry, physics, earth science, and technology courses. Curricular

  6. Oil-material fractionation in Gulf deep water horizontal intrusion layer: Field data analysis with chemodynamic fate model for Macondo 252 oil spill.

    Science.gov (United States)

    Melvin, A T; Thibodeaux, L J; Parsons, A R; Overton, E; Valsaraj, K T; Nandakumar, K

    2016-04-15

    Among the discoveries of the Deepwater Horizon blowout was the so-called "sub-surface plume"; herein termed the "oil-trapping layer". Hydrocarbons were found positioned at ~1100-1300m with thickness ~100-150m and moving horizontally to the SW in a vertically stratified layer at the junction of the cold abyssal water and the permanent thermocline. This study focuses on its formation process and fate of the hydrocarbons within. The originality of this work to the field is two-fold, first it provides a conceptual framework which places layer origin in the context of a horizontal "intrusion" from the near-field, vertical, blow-out plume and second, it offers a theoretical model for the hydrocarbon chemicals within the horizontal layer as it moves far-afield. The model quantifies the oil-material fractionation process for the soluble and fine particle. The classical Box model, retrofitted with an internal gradient, the "G-Box", allows an approach that includes turbulent eddy diffusion coupled with droplet rise velocity and reactive decay to produce a simple, explicit, transparent, algebraic model with few parameters for the fate of the individual fractions. Computations show the soluble and smallest liquid droplets moving very slowly vertically through the layer appearing within the trapping layer at low concentration with high persistence. The larger droplets move-through this trapping zone quickly, attain high concentrations, and eventually form the sea surface slick. It impacts the field of oil spill engineering science by providing the conceptual idea and the algorithms for projecting the quantities and fractions of oil-material in a deep water, horizontal marine current being dispersed and moving far afield. In the field of oil spill modeling this work extends the current generation near-field plume source models to the far-field. The theory portrays the layer as an efficient oil-material trap. The model-forecasted concentration profiles for alkanes and aromatics

  7. La banque de données platform de l'Institut français du pétrole : un outil de base pour des études de risque Ifp's Platform Databank: a Basic Implement for Risk Analysis

    Directory of Open Access Journals (Sweden)

    Bertrand A. R. V.

    2006-11-01

    information file, including a synthesis data sheet for each accident giving a selection of important facts (date, location, type of accident, etc. and summarizing the most probable sequence of events of the accident and their consequences, and (2 a computerized databank giving the most important facts for each accident in a strictly controlled language of codes and abbreviations for use in statistical analysis. The computerized databank contains 25 different parameters. Some are made up of multiple components (there are three preliminary factors, four sequences of events, etc. , and others are codes with sub-elements. Data has been entered in three different ways : as uncoded facts, as simple codes, or as complex codes. The latter have enabled a detailed analysis to be made of certain important factors, such as : (a 72 possible preliminary factors preceding the accident (b 74 different kinds of events making up a sequence of events (including 5 different types of blowout and 13 types of collision(c 196 countries, provinces or states (d 30 major geographic zones(e 139 different constructors of platforms, drillships or barges. An analysis of the number of accidents per year from 1972 to 1988 shows a good correlation with the evolution of the price of crude oil during the same period and that of world rig utilization. A comparison with the number of new rigs put onto the market from 1977 to 1988 shows a peak in accidents for the same years, reflecting the fact that new rigs are often subject to accidents at the start of operations. These comparisons serve to demonstrate the good correlation of the PLATFORM databank with results from other studies. PLATFORM can be used to draw up simple data sheets, such as the two lists given of the accidents having caused the most human casualties as well as those having caused the greatest oil spills. It can be used to furnish the probabilities of occurrence of unusual types of accidents, or to give a figure for well-known high-risk activities

  8. Searching for Environments That Could Support Life: Lessons Learned From Six Deep Sea Cruises with the Sentry and Nereus Autonomous Underwater Vehicles

    Science.gov (United States)

    Yoerger, D. R.; Kinsey, J. C.; Jakuba, M.; Camilli, R.; German, C. R.; Shank, T. M.; Bowen, A.; Nakamura, K.; Seeps 2009 Science Team; Oases 2009 Science Team; Gruvee 2010 Science Team; Enlighten 2010 Science Team; Hmmv 2010 Science Team

    2010-12-01

    In the past year, we have used our Sentry and Nereus Autonomous Underwater Vehicles (AUV) on six deep sea cruises searching for extreme environments that can support life. Two of these cruises took place on Mid-Ocean Ridge terrain (Mid Cayman Rise, Galapagos Rift), three on active methane seeps (Santa Monica/Santa Barbara Basins, Hydrate Ridge, Haakon-Mosby Mud Volcano), and one took place at the site of the Deepwater Horizon blowout. This presentation summarizes how we used the vehicles, their automatic control systems, and their sensor suites in these different environments to identify and quantify chemical fluxes emerging from the seafloor. We also took advantage of complementary data from lowered and towed platforms. Examples will include the following: * ●In the Cayman Trough and the Galapagos Rift, we used in-situ chemical sensing (conductivity, temperature, optical backscatter, and redox potential) to locate hydrothermal sources. * ●In the Galapagos Rift, we also used our 400khz multibeam sonar to locate hydrothermal sites using acoustic backscatter from plumes and by building bathymetric maps of likely hydrothermal structures. * ●In the Santa Monica and Santa Barbara Basins, we used the TETHYS in-situ mass spectrometer to locate active methane seeps and to determine the ratio of biogenic to thermogenic methane through isotopic analysis. We used this information in real-time to alter the vehicle's trajectory and, hence, improve measurements over the most interesting locations. * ●At the site of the Deepwater Horizon blowout, we used Sentry and TETHYS to map a deep hydrocarbon plume from just outside the vessel exclusion zone out to a distance of 35 km. Analysis of oxygen data from an electrode, an optode, the mass spectrometer, and from titration of samples brought to the surface supported estimates of microbial respiration rates. * ●On Hydrate Ridge, we showed that the 400khz multibeam sonar is an effective tool for locating active methane bubble

  9. A mechanism for the origin and development of the large-scale dunefield on the right flank of the lower reach of Laoha River, Northeast China

    Institute of Scientific and Technical Information of China (English)

    Guang Han; GuiFang Zhang; Li You; Liang Zhou; Lin Yang; XueYong Zhao; YuLin Li; TongHui Zhang

    2015-01-01

    By viewing satellite imagery, a striking large-scale dunefield can be clearly perceived, with a size of nearly 63 km long and 11 km wide, and trending NE–SW, on the right flank of the lower Laoha River, Northeast China. By means of remote sensing imagery analysis and field observation as well as a comparison with a small-scale dunefield on the right flank of the lower Xiangshui River, analogous to the case of the lower Laoha River, this paper presents a new mechanism for its origin and development. The results show that:(1) the large-scale dunefield bears a tile-style framework overwhelmingly composed of transverse barchanoid ridges perpendicular to the predominant winds, and inlaid diverse blowouts. (2) The small-scale dunefield, referred to as a primary structural unit of the large one, is typical of an incipient dunefield, following the same rules of evolution as the larger. (3) A succession of barchanoid ridge chains can steadily migrate downwind in much the same manner as surface wave propagation in air or water stimulated by an incised valley, and ultimately tend to bear roughly the same wavelength and amplitude under stable climate and hydrologic regimes. (4) The first ridge chain acquires its sand source substantially from the downwind escarpments exposing the loose Quaternary sandy sediments to the air, while the ensuing ridges derive their sands dominantly from in situ deflation of the underlain Quaternary loose sandy sediments in blowouts, partly from the upwind ridges through northern elongated horns. Theoretically, the sands from riparian escarpments can be transported by wind to the downwind distal end of a dunefield after sufficient long du-ration. (5) The lower Laohahe region experienced probably three significant climatic changes in the past, corresponding to the three active dune belts, suggesting that once a large-scale dunefield occurs, it is nearly impossible to be completely stabilized, at least in its central portions. At present, seasonal

  10. Methane gas seepage - Disregard of significant water column filter processes?

    Science.gov (United States)

    Schneider von Deimling, Jens; Schmale, Oliver

    2016-04-01

    Marine methane seepage represents a potential contributor for greenhouse gas in the atmosphere and is discussed as a driver for climate change. The ultimate question is how much methane is released from the seafloor on a global scale and what fraction may reach the atmosphere? Dissolved fluxes from methane seepage sites on the seabed were found to be very efficiently reduced by benthic microbial oxidation, whereas transport of free gas bubbles from the seabed is considered to bypass the effective benthic methane filter. Numerical models are available today to predict the fate of such methane gas bubble release to the water column in regard to gas exchange with the ambient water column, respective bubble lifetime and rise height. However, the fate of rising gas bubbles and dissolved methane in the water column is not only governed by dissolution, but is also affected by lateral oceanographic currents and vertical bubble-induced upwelling, microbial oxidation, and physico-chemical processes that remain poorly understood so far. According to this gap of knowledge we present data from two study sites - the anthropogenic North Sea 22/4b Blowout and the natural Coal Oil point seeps - to shed light into two new processes gathered with hydro-acoustic multibeam water column imaging and microbial investigations. The newly discovered processes are hereafter termed Spiral Vortex and Bubble Transport Mechanism. Spiral Vortex describes the evolution of a complex vortical fluid motion of a bubble plume in the wake of an intense gas release site (Blowout, North Sea). It appears very likely that it dramatically changes the dissolution kinetics of the seep gas bubbles. Bubble Transport Mechanism prescribes the transport of sediment-hosted bacteria into the water column via rising gas bubbles. Both processes act as filter mechanisms in regard to vertical transport of seep related methane, but have not been considered before. Spiral Vortex and Bubble Transport Mechanism represent the

  11. The effect of fuel/air mixer design parameters on the continuous and discrete phase structure in the reaction-stabilizing region

    Science.gov (United States)

    Ateshkadi, Arash

    The demands on current and future aero gas turbine combustors are demanding a greater insight into the role of the injector/dome design on combustion performance. The structure of the two-phase flow and combustion performance associated with practical injector/dome hardware is thoroughly investigated. A spray injector with two radial inflow swirlers was custom-designed to maintain tight tolerances and strict assembly protocol to isolate the sensitivity of performance to hardware design. The custom set is a unique modular design that (1) accommodates parametric variation in geometry, (2) retains symmetry, and (3) maintains effective area. Swirl sense and presence of a venturi were found to be the most influential on fuel distribution and Lean Blowout. The venturi acts as a fuel-prefilming surface and constrains the highest fuel mass concentration to an annular ring near the centerline. Co-swirl enhances the radial dispersion of the continuous phase and counter-swirl increases the level of mixing that occurs in the downstream region of the mixer. The smallest drop size distributions were found to occur with the counter-swirl configuration with venturi. In the case of counter-swirl without venturi the high concentration of fluid mass is found in the center region of the flow. The Lean Blowout (LBO) equivalence ratio was lower for counter-swirl due to the coupling of the centerline recirculation zone with the location of high fuel concentration emanating from smaller droplets. In the co-swirl configuration a more intense reaction was found near the mixer exit leading to the lowest concentration of NOx, CO and UHC. An LBO model with good agreement to the measured values was developed that related, for the first time, specific hardware parameters and operating condition to stability performance. A semi-analytical model, which agreed best with co-swirl configurations, was modified and used to describe the axial velocity profile downstream of the mixer exit. The

  12. The Caroline interrogatory process

    Energy Technology Data Exchange (ETDEWEB)

    Degagne, D. [Alberta Energy and Utilities Board, Calgary, AB (Canada); Gibson, T. [Gecko Management, Calgary, AB (Canada)

    1999-11-01

    Using the specific case study of the Caroline interrogatory process, an example is given of how an effective communications and public involvement program can re-establish trust and credibility levels within an community after an incident. The public is nervous about sour gas, especially about blowouts of gas from a pipeline. The post-approval period was marked by high expectations and a community consultation program which included a community advisory board, an emergency planning committee, socio-economic factors, and environmental monitoring and studies. Information and education involves newspaper articles, newsletters, tours, public consultation meetings, and weekly e-mail. Mercury was detected as a potential hazard at the site, and company actions are illustrated. Overall lessons learned included: starting early paid off, face to face resident contacts were the most effective, the willingness to make changes was the key to success, the community helped, knowing all the answers is not essential, and there is a need for empathy. The interrogatory process includes a hybrid technique that is comprised of four stages: 1) process review and public input, 2) identification and clarification of issues, 3) responses by industry and government, and 4) a public forum and follow-up action.

  13. The Caroline interrogatory process

    Energy Technology Data Exchange (ETDEWEB)

    Degagne, D. (Alberta Energy and Utilities Board, Calgary, AB (Canada)); Gibson, T. (Gecko Management, Calgary, AB (Canada))

    1999-01-01

    Using the specific case study of the Caroline interrogatory process, an example is given of how an effective communications and public involvement program can re-establish trust and credibility levels within an community after an incident. The public is nervous about sour gas, especially about blowouts of gas from a pipeline. The post-approval period was marked by high expectations and a community consultation program which included a community advisory board, an emergency planning committee, socio-economic factors, and environmental monitoring and studies. Information and education involves newspaper articles, newsletters, tours, public consultation meetings, and weekly e-mail. Mercury was detected as a potential hazard at the site, and company actions are illustrated. Overall lessons learned included: starting early paid off, face to face resident contacts were the most effective, the willingness to make changes was the key to success, the community helped, knowing all the answers is not essential, and there is a need for empathy. The interrogatory process includes a hybrid technique that is comprised of four stages: 1) process review and public input, 2) identification and clarification of issues, 3) responses by industry and government, and 4) a public forum and follow-up action.

  14. High resolution shallow geologic characterization of a late Pleistocene eolian environment using ground penetrating radar and optically stimulated luminescence techniques: North Carolina, USA

    Science.gov (United States)

    Mallinson, D.; Mahan, S.; Moore, Christine

    2008-01-01

    Geophysical surveys, sedimentology, and optically-stimulated luminescence age analyses were used to assess the geologic development of a coastal system near Swansboro, NC. This area is a significant Woodland Period Native American habitation and is designated the "Broad Reach" archaeological site. 2-d and 3-d subsurface geophysical surveys were performed using a ground penetrating radar system to define the stratigraphic framework and depositional facies. Sediment samples were collected and analyzed for grain-size to determine depositional environments. Samples were acquired and analyzed using optically stimulated luminescence techniques to derive the depositional age of the various features. The data support a low eolian to shallow subtidal coastal depositional setting for this area. Li-DAR data reveal ridge and swale topography, most likely related to beach ridges, and eolian features including low-relief, low-angle transverse and parabolic dunes, blowouts, and a low-relief eolian sand sheet. Geophysical data reveal dominantly seaward dipping units, and low-angle mounded features. Sedimentological data reveal mostly moderately-well to well-sorted fine-grained symmetrical to coarse skewed sands, suggesting initial aqueous transport and deposition, followed by eolian reworking and bioturbation. OSL data indicate initial coastal deposition prior to ca. 45,000 yBP, followed by eolian reworking and low dune stabilization at ca. 13,000 to 11,500 yBP, and again at ca. 10,000 yBP (during, and slightly after the Younger Dryas chronozone).

  15. Dynamic Response of High-Pressure Riser of Deepwater SBOP System

    Directory of Open Access Journals (Sweden)

    Kanhua Su

    2012-08-01

    Full Text Available The application of surface blowout preventer (SBOP drilling system in deepwater environments has been demonstrated that it can save operation cost and time. The high pressure small diameter casing plays the role of the conventional riser and bears the complex loading caused by the wave and current force and drilling platform motion. The coupled quasi-static and uncoupled dynamic analysis models of deepwater SBOP drilling system were established. The analysis results indicate that the uncoupled method without consider the lateral offset on the end of the high pressure riser nearly no affection to the riser analysis. However, the uncoupled method has a certain impact on the mechanical analysis of the subsea wellhead and the casing string under mudline. The lateral offset of the high pressure riser changes greatly in the different times, the bending moment of the upper and lower stress joint of riser is bigger. The platform long-term drift has a greater impact on the dynamic response analysis of the high pressure riser of SBOP system for deepwater drilling.

  16. Preliminary studies to determine the shelf life of HEPA filters

    Energy Technology Data Exchange (ETDEWEB)

    Gilbert, H.; Fretthold, J.K.; Rainer, F. [Lawrence Livermore National Laboratory, CA (United States)] [and others

    1995-02-01

    We have completed a preliminary study using filter media tests and filter qualification tests to investigate the effect of shelf-life on HEPA filter performance. Our media studies showed that the tensile strength decreased with age, but the data were not sufficient to establish a shelf-life. Thermogravimetric analyses demonstrated that one manufacturer had media with low tensile strength due to insufficient binder. The filter qualification tests (heated air and overpressure) conducted on different aged filters showed that filter age is not the primary factor affecting filter performance; materials and the construction design have a greater effect. An unexpected finding of our study was that sub-standard HEPA filters have been installed in DOE facilities despite existing regulations and filter qualification tests. We found that the filter with low tensile strength failed the overpressure test. The same filter had passed the heated air test, but left the filter so structurally weak, it was prone to blow-out. We recommend that DOE initiate a filter qualification program to prevent this occurrence.

  17. Study of Picture Archiving and Communications System for application of orbital disease%眼眶病变中PACS图像系统的应用

    Institute of Scientific and Technical Information of China (English)

    韩晓晖; 施明光

    2009-01-01

    目的 探讨眼眶病变中PACS图像系统的诊断价值.方法 对70例眼眶病变患者行眼眶CT检查,部分行MRI,DSA检查.结果 在70例眼眶疾病中眼眶骨折38例,海绵状血管瘤4例,皮样囊肿3例,眼眶异物2例,其他23例.PACS图像系统能有效提高诊断率.结论 PACS图像系统在眼眶病变中的诊断中具有重要价值,并能指导手术方案的设计.%Objective To study of Picture Archiving and Communications System for application in orbital disease.Methods Picture Archiving and Communications System was performed on orbital disease of 70 cases.Results The orbital disease included blow-out fracture in 70 cases,blow-out fracture 38 cases,venous angioma 4 cases,dermoid cyst 3 cases,orbital foreign body 2 case and others 14 cases.Conclusions Picture Archiving and Communications System can provide accurate diagnosis for orbital disease and instruct operate scheme.

  18. Observations of a Series of Flares and Associated Jet-like Eruptions Driven by the Emergence of Twisted Magnetic Fields

    CERN Document Server

    Lim, Eun-Kyung; Park, Sung-Hong; Kim, Sujin; Cho, Kyung-Suk; Kumar, Pankaj; Chae, Jongchul; Yang, Heesu; Cho, Kyuhyoun; Song, Donguk; Kim, Yeon-Han

    2015-01-01

    We studied temporal changes of morphological and magnetic properties of a succession of four confined flares followed by an eruptive flare using the high-resolution New Solar Telescope (NST) operating at the Big Bear Solar Observatory (BBSO), Helioseismic and Magnetic Imager (HMI) magnetograms and Atmospheric Image Assembly (AIA) EUV images provided by Solar Dynamics Observatory (SDO). From the NST/Halpha and the SDO/AIA~304 A observations we found that each flare developed a jet structure that evolved in a manner similar to evolution of the blowout jet : 1) an inverted-Y shape jet appeared and drifted away from its initial position; 2) jets formed a curtain-like structure that consisted of many fine threads accompanied with subsequent brightenings near the footpoints of the fine threads; and finally 3) the jet showed a twisted structure visible near the flare maximum. Analysis of the HMI data showed that both the negative magnetic flux and the magnetic helicity have been gradually increasing in the positive ...

  19. Spatial distribution of metal emissions in supernova remnant 3C 397 viewed with Chandra and XMM

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    We present X-ray equivalent width imaging of 3C 397 for Mg Heα,Si Heα,S Heα,and Fe Kα complex lines with Chandra and XMM-Newton observations.The images revealed that the heavier the element is,the smaller the extent of the element distribution is.The Mg emission is evidently enhanced in the southeastern blow-out region,well along the radio boundary there,and appears to partially envelope the eastern Fe knot.Two bilateral hat-like Si line-emitting structures are along the northern and southern borders,roughly symmetric with respect to the south-east-northwest elongation axis.An S line-emitting shell is located just inside the northern radio and IR shell,indicating a layer of reversely shocked sulphur in the ejecta.A few enhanced Fe features are basically aligned along the diagonal of the rectangular shape of the SNR,which implicates an early asymmetric SN explosion.

  20. Herschel Observations and Updated Spectral Energy Distributions of Five Sunlike Stars with Debris Disks

    CERN Document Server

    Dodson-Robinson, Sarah E; Bryden, Geoff; Harvey, Paul M; Green, Joel D

    2016-01-01

    Observations from the Herschel Space Observatory have more than doubled the number of wide debris disks orbiting Sunlike stars to include over 30 systems with R > 100 AU. Here we present new Herschel PACS and re-analyzed Spitzer MIPS photometry of five Sunlike stars with wide debris disks, from Kuiper belt size to R > 150 AU. The disk surrounding HD 105211 is well resolved, with an angular extent of >14" along the major axis, and the disks of HD 33636, HD 50554, and HD 52265 are extended beyond the PACS PSF size (50% of energy enclosed within radius 4.23"). HD 105211 also has a 24-micron infrared excess that was previously overlooked because of a poorly constrained photospheric model. Archival Spitzer IRS observations indicate that the disks have small grains of minimum radius ~3 microns, though the minimum grain gradius is larger than the radiation pressure blowout size in all systems. If modeled as single-temperature blackbodies, the disk temperatures would all be <60 K. Our radiative transfer models pre...

  1. Oil spill in the Gulf of Mexico and spiral vortex

    Institute of Scientific and Technical Information of China (English)

    ZHENG Quanan; ZHAO Qing; Nan Walker; LI Chunyan

    2010-01-01

    @@ Drilling rig Decpwater Horizon in the Gulf of Mexico, leased by BP PLC from Transocean Ltd., ex-ploded and caught on fire on April 20, 2010. The drilling location is at some 50 miles (80 kilometers) off the coast of Louisiana, USA. The rig sank on April 22. Since then, oil has been pouring into the Gulf from the blown-out undersea well. As reported by US Today and Calgary Herald on July 3, an estimated 35 000 to 60 000 barrels of oil per day has been gush-ing out of the ruptured well into the Gulf. That means amounts to a total of 1.9 to 3.6 million barrels of oil so far have gushed into the Gulf. Using the high end of that estimate, the spill has now surpassed the 1979 Ixtoc blowout, which took nine months to cap and dumped estimated 3.3 million barrels (140 000 million gallons) into the Gulf of Mexico. It is topped only by the deliberate release of six to eight million barrels of crude oil by Iraqi troops who destroyed tankers and oil terminals and set wells ablaze in Kuwait during the 1991 Gulf War.

  2. Multi-Element Abundance Measurements from Medium-Resolution Spectra. IV. Alpha Element Distributions in Milky Way Satellite Galaxies

    CERN Document Server

    Kirby, Evan N; Smith, Graeme H; Majewski, Steven R; Sohn, Sangmo Tony; Guhathakurta, Puragra

    2010-01-01

    We derive the star formation histories of eight dwarf spheroidal (dSph) Milky Way satellite galaxies from their alpha element abundance patterns. Nearly 3000 stars from our previously published catalog (Paper II) comprise our data set. The average [alpha/Fe] ratios for all dSphs follow roughly the same path with increasing [Fe/H]. We do not observe the predicted knees in the [alpha/Fe] vs. [Fe/H] diagram, corresponding to the metallicity at which Type Ia supernovae begin to explode. Instead, we find that Type Ia supernova ejecta contribute to the abundances of all but the most metal-poor ([Fe/H] < -2.5) stars. We have also developed a chemical evolution model that tracks the star formation rate, Types II and Ia supernova explosions, and supernova feedback. Without metal enhancement in the supernova blowout, massive amounts of gas loss define the history of all dSphs except Fornax, the most luminous in our sample. All six of the best-fit model parameters correlate with dSph luminosity but not with velocity ...

  3. Attempt to determine the influence of pressure distribution in the vicinity of a mine drift on permeability of a rock massif

    Energy Technology Data Exchange (ETDEWEB)

    Hrastnik, J.; Mayer, J.

    1982-01-01

    An attempt was made to clarify why free gas in the zones of tectonic disorders cannot be successfully removed through the advance boreholes of diameter over 100mm, but when the face of the drift approaches the disrupted zone, gas release can rise sharply and result in sudden blowout of coal and gas. For this purpose a study was made of gas permeability of the rocks in the vicinity of the drift depending on the stresses active in it. Experiments were conducted under laboratory conditions on coal samples from the disrupted zones, changing the load on the samples and the pressure of the gas. It is indicated that gas permeability depends to a great measure on the load on the samples, especially for smallgrained or water-saturated coal, which in the loaded state is impermeable for gas, and with reduced load below the gas pressure a spasmodic rise occurs in the gas permeability. Measurement of gas permeability with pressure of gas 0.25 MPa was done in the interval of change in comprehensive pressure from 0.3 to 5 Mpa, and with gas pressure 0.5 MPa from 0.6 to 5 MPa. Experiments were conducted on samples with known granulometric composition taken in different mine drifts and in a state of natural moisture content and at different levels of moisture saturation. Experimental curves are presented.

  4. Need for airbag and seatbelt to reduce orbital injuries from steering wheel knob.

    Science.gov (United States)

    Hwang, Kun; Kim, Joo Ho

    2014-11-01

    The aims of this study are to report a blowout fracture of the orbital floor and medial wall caused by being struck by a steering wheel knob of an automobile and to discuss the use of airbags and seatbelts as a preventive measure for orbital injuries. A 58-year-old man was struck in the left eye by a steering wheel. His car hit a telephone pole, and he had a frontal collision injury. In this frontal impact, his left eye was hit by a Brodie knob attached to the steering wheel. At the time of injury, the speed of the car was about 65 km/h. He was not wearing a seatbelt, and the airbag had not deployed. Swelling and ecchymosis were observed at the left periorbital area, and he had diplopia on a left-side gaze. A CT revealed fractures in the medial and inferior wall of the left orbit. Entrapped soft tissues were reduced, and the medial wall and floor were reconstructed with a resorbable sheet. His diplopia disappeared 12 days after surgery. To prevent the injury from the steering wheel knob, an airbag should be installed in any vehicle, which has a steering wheel knob. Legislation mandating the use of airbags as well as seatbelts in vehicles with attached steering wheel knobs should be made.

  5. Maxillofacial fractures in the province of Latina, Lazio, Italy: review of 400 injuries and 83 cases.

    Science.gov (United States)

    Arangio, Paolo; Vellone, Valentino; Torre, Umberto; Calafati, Vincenzo; Capriotti, Marco; Cascone, Piero

    2014-07-01

    A retrospective study was performed to assess maxillofacial fractures in patients treated at the public "S.M. Goretti Hospital" hospital from 2011 to 31/8/2012. Data were prospectively recorded including age and sex, cause and mechanisms of injury, soft tissue injuries, dentoalveolar trauma, facial bone fractures and type of treatment. The pre-surgical and post-surgical hospitalization days were also analysed. Causes were grouped into five categories: road traffic collision, sports accidents, occupational accidents, assaults and domestic accidents. The analyses involved descriptive statistics. Records from 83 patient sustaining 95 maxillofacial fractures were evaluated. The zygoma was the most fractured anatomical site in both males and females, accounting for 32% of injuries, followed by isolated fracture of the orbital floor (blow-out and blow-in) with 11%. The age group between 18 and 39 years showed the highest rate of incidence of maxillofacial fractures. Men were more involved than women in all cases with a male:female ratio of 5,4:1. Accidents were the most frequent cause of maxillofacial fractures in the age group between 18 and 39 years and interpersonal violence was the most frequent cause of maxillofacial fractures in the age group between 40 and 59 years. Facial fractures occurred primarily among men under 30 years of age, and the most common sites of fractures in the face were the mandible and the zygomatic complex. Road traffic collisions were the main aetiologic factor associated with maxillofacial trauma.

  6. An overview of uncertainty quantification techniques with application to oceanic and oil-spill simulations

    KAUST Repository

    Iskandarani, Mohamed

    2016-04-22

    We give an overview of four different ensemble-based techniques for uncertainty quantification and illustrate their application in the context of oil plume simulations. These techniques share the common paradigm of constructing a model proxy that efficiently captures the functional dependence of the model output on uncertain model inputs. This proxy is then used to explore the space of uncertain inputs using a large number of samples, so that reliable estimates of the model\\'s output statistics can be calculated. Three of these techniques use polynomial chaos (PC) expansions to construct the model proxy, but they differ in their approach to determining the expansions\\' coefficients; the fourth technique uses Gaussian Process Regression (GPR). An integral plume model for simulating the Deepwater Horizon oil-gas blowout provides examples for illustrating the different techniques. A Monte Carlo ensemble of 50,000 model simulations is used for gauging the performance of the different proxies. The examples illustrate how regression-based techniques can outperform projection-based techniques when the model output is noisy. They also demonstrate that robust uncertainty analysis can be performed at a fraction of the cost of the Monte Carlo calculation.

  7. On the Fate of Processed Matter in Dwarf Galaxies

    CERN Document Server

    Silich, S A; Silich, Sergey A.; Tenorio-Tagle, Guillermo

    1998-01-01

    Two dimensional calculations of the evolution of remnants generated by the strong mechanical energy deposited by stellar clusters in dwarf galaxies (M \\si $10^9 - 10^{10}$ \\msun) are presented. The evolution is followed for times longer than both the blowout time and the presumed span of energy injection generated by a coeval massive stellar cluster. The remnants are shown to end up wrapping around the central region of the host galaxy, while growing to kpc-scale dimensions. Properties of the remnants such as luminosity, size, swept up mass, and expansion speed are given as a function of time for all calculated cases. The final fate of the swept-up galactic gas and of the matter processed by the central starburst is shown to be highly-dependent on the properties of the low density galactic halo. Superbubbles powered by star clusters, with properties similar to those inferred from the observations, slow down in the presence of an extended halo to expansion speeds smaller than the host galaxy escape velocity. V...

  8. Kinematical analysis of the ionized gas in the nuclear region of NGC 4214

    CERN Document Server

    Maíz-Appelániz, J; Mas-Hesse, J M; Tenorio-Tagle, G

    1999-01-01

    We present in this paper a detailed study of the kinematical properties of the ionized gas around the young massive star clusters in the nucleus of NGC 4214. The analysis is based on bidimensional spectroscopical data, allowing to derive the spatial variation of different properties (intensity, velocity and width / line splitting) of the emission lines H\\alpha and [O III] \\lambda 5007 along the nuclear region. We have found that the Giant H II region around the two most massive clusters in NGC 4214 (A and B) is resolved into two clearly separated regions. We have not detected superbubbles with the properties we would expect according to the evolutionary state of the stellar clusters, but just a partial ring feature around the most massive one and two expanding shells around cluster B. The first expanding shell seems to have experienced blowout, whereas the second one is still complete. A possible explanation to this phenomenon is that the most massive stars in a starburst spend a large fraction of their lives...

  9. Management of orbital fractures: challenges and solutions

    Directory of Open Access Journals (Sweden)

    Boyette JR

    2015-11-01

    Full Text Available Jennings R Boyette,1 John D Pemberton,2 Juliana Bonilla-Velez1 1Department of Otolaryngology-Head and Neck Surgery, 2Department of Ophthalmology, University of Arkansas for Medical Sciences, Little Rock, AR, USA Abstract: Many specialists encounter and treat orbital fractures. The management of these fractures is often challenging due to the impact that they can have on vision. Acute treatment involves a thorough clinical examination and management of concomitant ocular injuries. The clinical and radiographic findings for each individual patient must then be analyzed for the need for surgical intervention. Deformity and vision impairment can occur from these injuries, and while surgery is intended to prevent these problems, it can also create them. Therefore, surgical approach and implant selection should be carefully considered. Accurate anatomic reconstruction requires complete assessment of fracture margins and proper implant contouring and positioning. The implementation of new technologies for implant shaping and intraoperative assessment of reconstruction will hopefully lead to improved patient outcomes. Keywords: orbital fracture, orbital blowout, orbital floor

  10. Explosions during galaxy formation

    Directory of Open Access Journals (Sweden)

    Hugo Martel

    2001-01-01

    Full Text Available As an idealized model of the e ects of energy release by supernovae during galaxy formation, we consider an explosion at the center of a halo which forms at the intersection of laments in the plane of a cosmological pancake by gravitational instability during pancake collapse. Such halos resemble the virialized objects found in N{body simulations in a CDM universe and, therefore, serve as a convenient, scale{free test{bed model for galaxy formation. ASPH=P3M simulations reveal that such explosions are anisotropic. The energy and metals are channeled into the low density regions, away from the pancake plane. The pancake remains essentially undisturbed, even if the explosion is strong enough to blow away all the gas lo- cated inside the halo at the onset of the explosion and reheat the IGM surrounding the pancake. Infall quickly replenishes this ejected gas and gradually restores the gas fraction as the halo mass continues to grow. Estimates of the collapse epoch and SN energy{release for galaxies of di erent mass in the CDM model can re- late these results to scale{dependent questions of blow{out and blow{away and their implication for early IGM heating and metal enrichment and the creation of dark{matter{dominated dwarf galaxies.

  11. Overall analysis report on the fiscal 1994 geothermal development promotion survey. No.C-2. Wasabizawa area (secondary); 1994 nendo chinetsu kaihatsu sokushin chosa sogo kaiseki hokokusho. No.C-2. Wasabizawa chiiki (dainiji)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-01-01

    The Wasabizawa area is located near the boundary between Yuzawa city south of Akita pref. and Ogachi-machi, Ogachi-gun, Akita pref, having a range of 3.0km northeast-southwest and 2.5km northwest-southeast of Wasabizawa almost as a center. The area for survey and its circumference are national forests, and the east and a part of the south of the area are designated as the Kurikoma quasi-national park third type special region. From the geochemical temperature distribution, it can be assumed that geothermal fluids of around 300{degree}C exist in the deep underground of the Kaminotai-Wasabizawa-Akinomiya area. From the distribution of density basements, the block structure of the basement can be estimated. Around the boundary of the ridge/sedimentation region of this density basement, fractures develop and the formation of reservoir structure is expected from the comparison with the result of the well survey. In the blowout test, obtained were 284.3{degree}C and 83.05 kgf/cm{sup 2} at a depth of 1,300m. In the geothermal system, it is assumed that reservoir structures of geothermal fluids develop in the deep underground of the central part of the area. The heat source to the geothermal system is supposed to be the magma reservoir remaining in Takamatsudake volcanic rocks. 110 refs., 177 figs., 105 tabs.

  12. Resolving The Moth at Millimeter Wavelengths

    CERN Document Server

    Ricarte, Angelo; Hughes, A Meredith; Duchêne, Gaspard; Williams, Jonathan P; Andrews, Sean M; Wilner, David J

    2013-01-01

    HD 61005, also known as "The Moth," is one of only a handful of debris disks that exhibit swept-back "wings" thought to be caused by interaction with the ambient interstellar medium (ISM). We present 1.3 mm Submillimeter Array (SMA) observations of the debris disk around HD 61005 at a spatial resolution of 1.9 arcsec that resolve the emission from large grains for the first time. The disk exhibits a double-peaked morphology at millimeter wavelengths, consistent with an optically thin ring viewed close to edge-on. To investigate the disk structure and the properties of the dust grains we simultaneously model the spatially resolved 1.3 mm visibilities and the unresolved spectral energy distribution. The temperatures indicated by the SED are consistent with expected temperatures for grains close to the blowout size located at radii commensurate with the millimeter and scattered light data. We also perform a visibility-domain analysis of the spatial distribution of millimeter-wavelength flux, incorporating constr...

  13. From synchronisation to persistent optical turbulence in laser arrays

    Science.gov (United States)

    Blackbeard, Nicholas; Wieczorek, Sebastian; Erzgräber, Hartmut; Dutta, Partha Sharathi

    2014-10-01

    We define and study synchronisation in a linear array of nearest-neighbour coupled lasers. Our focus is on possible synchronisation types and the stability of their corresponding synchronisation manifolds with dependence on the coupling strength, the laser frequency detuning, the amount of shear (amplitude-phase coupling) in a single laser, and the array size. We classify, and give analytical conditions for the existence of complete synchronisation solutions, where all the lasers emit light with the same intensity and frequency. Furthermore, we derive stability criteria for two special cases where all the lasers oscillate (i) in-phase with each other and (ii) in anti-phase with their nearest neighbour(s). We then explain transitions from complete synchronisation, to partial synchronisation (where only a subset of the lasers synchronises), to persistent optical turbulence (where no lasers synchronise and each laser is chaotic) in terms of bifurcations including blowouts of chaotic attractors. Finally, we quantify properties of optical turbulence using Lyapunov spectrum and dimension, which highlights differences in chaos generated by nearest-neighbour and globally coupled oscillators.

  14. Customizable electron beams from optically controlled laser plasma acceleration for γ-ray sources based on inverse Thomson scattering

    Science.gov (United States)

    Kalmykov, S. Y.; Davoine, X.; Ghebregziabher, I.; Shadwick, B. A.

    2016-09-01

    Laser wakefield acceleration of electrons in the blowout regime can be controlled by tailoring the laser pulse phase and the plasma target. The 100 nm-scale bandwidth and negative frequency chirp of the optical driver compensate for the nonlinear frequency red-shift imparted by wakefield excitation. This mitigates pulse self-steepening and suppresses continuous injection. The plasma channel suppresses diffraction of the pulse leading edge, further reducing self-steepening, making injection even quieter. Besides, the channel destabilizes the pulse tail confined within the accelerator cavity (the electron density "bubble"), causing oscillations in the bubble size. The resulting periodic injection generates background-free comb-like beams - sequences of synchronized, low phase-space volume bunches. Controlling the number of bunches, their energy, and energy spacing by varying the channel radius and the pulse length (as permitted by the large bandwidth) enables the design of a tunable, all-optical source of polychromatic, pulsed γ-rays using the mechanism of inverse Thomson scattering. Such source may radiate ~107 quasi-monochromatic 10 MeV-scale photons per shot into a microsteradian-scale observation angle. The photon energy is distributed among several distinct bands, each having sub-25% energy spread dictated by the mrad-scale divergence of electron beam.

  15. Parameter Estimation of a Delay Time Model of Wearing Parts Based on Objective Data

    Directory of Open Access Journals (Sweden)

    Y. Tang

    2015-01-01

    Full Text Available The wearing parts of a system have a very high failure frequency, making it necessary to carry out continual functional inspections and maintenance to protect the system from unscheduled downtime. This allows for the collection of a large amount of maintenance data. Taking the unique characteristics of the wearing parts into consideration, we establish their respective delay time models in ideal inspection cases and nonideal inspection cases. The model parameters are estimated entirely using the collected maintenance data. Then, a likelihood function of all renewal events is derived based on their occurring probability functions, and the model parameters are calculated with the maximum likelihood function method, which is solved by the CRM. Finally, using two wearing parts from the oil and gas drilling industry as examples—the filter element and the blowout preventer rubber core—the parameters of the distribution function of the initial failure time and the delay time for each example are estimated, and their distribution functions are obtained. Such parameter estimation based on objective data will contribute to the optimization of the reasonable function inspection interval and will also provide some theoretical models to support the integrity management of equipment or systems.

  16. Estimation of bioavailability of metals from drilling mud barite.

    Science.gov (United States)

    Neff, Jerry M

    2008-04-01

    Drilling mud and associated drill cuttings are the largest volume wastes associated with drilling of oil and gas wells and often are discharged to the ocean from offshore drilling platforms. Barite (BaSO4) often is added as a weighting agent to drilling muds to counteract pressure in the geologic formations being drilled, preventing a blowout. Some commercial drilling mud barites contain elevated (compared to marine sediments) concentrations of several metals. The metals, if bioavailable, may harm the local marine ecosystem. The bioavailable fraction of metals is the fraction that dissolves from the nearly insoluble, solid barite into seawater or sediment porewater. Barite-seawater and barite-porewater distribution coefficients (Kd) were calculated for determining the predicted environmental concentration (PEC; the bioavailable fraction) of metals from drilling mud barite in the water column and sediments, respectively. Values for Kdbarite-seawater and Kdbarite-porewater were calculated for barium, cadmium, chromium, copper, mercury, lead, and zinc in different grades of barite. Log Kdbarite-seawater values were higher (solubility was lower) for metals in the produced water plume than log Kdbarite-porewater values for metals in sediments. The most soluble metals were cadmium and zinc and the least soluble were mercury and copper. Log Kd values can be used with data on concentrations of metals in barite and of barite in the drilling mud-cuttings plume and in bottom sediments to calculate PECseawater and PECsediment.

  17. Experimental study on immiscible jet breakup using refractive index matched oil-water pair

    Science.gov (United States)

    Xue, Xinzhi; Katz, Joseph

    2016-11-01

    A subsea oil well blowout creates an immiscible crude oil jet. This jet fragments shortly after injection, resulting in generation of a droplet cloud. Detailed understanding of the processes involved is crucial for modeling the fragmentation and for predicting the droplet size distribution. High density of opaque droplets near nozzle limits our ability to visualize and quantify the breakup process. To overcome this challenge, two immiscible fluids: silicone oil and sugar water with the same index of refraction (1.4015) are used as surrogates for crude oil and seawater, respectively. Their ratios of kinematic viscosity (5.64), density (0.83) and interfacial tension are closely matched with those of crude oil and seawater. Distribution of the oil phase is visualized by fluorescent tagging. Both phases are also seeded with particles for simultaneous PIV measurements. The measurements are performed within atomization range of Ohnesorge and Reynolds numbers. Index matching facilitates undistorted view of the phase distribution in illuminated section. Ongoing tests show that the jet surface initially rolls up into Kelvin-Helmholtz rings, followed by development of dispersed phase ligaments further downstream, which then break into droplets. Some of these droplets are re-entrained into the high momentum core, resulting in secondary breakup. As the oil layer and ligaments evolve, they often entrain water, resulting in generation of multiple secondary water droplets encapsulated within the oil droplets. This research is made possible by a Grant from Gulf of Mexico Research Initiative.

  18. Estimation of performance of a high-speed boat by using the Rankine source method; Kosokutei no rankinsosuho ni yoru seino suitei ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Eguchi, T. [Mitsui Engineering and Shipbuilding Co. Ltd., Tokyo (Japan)

    1997-10-01

    This paper describes estimation of performance of a high-speed boat by using the Rankine source method. An orthogonal coordinate system is considered, which uses the center of a hull as the zero point, and is made dimensionless by using the hull length. The catamaran boat or the single hull boat being the subject of the discussion is supposed to have a transom stern, and to be sailing at a constant speed in the -X direction. A governing equation and a border condition were formulated using disturbance speed potential and X-direction speed differentiation. An inverse specular image was employed as a specular image system upon considering attitude change in the high-speed boat. As to the division of hull surface, the portions protruded above the static water surface were cut off from among the panel data of boat CAD. Considering a high speed condition in which the water surface is completely separated at the transom section, the water level at the transom section was supposed to be at the same height as at the rear end of the hull. Blow-out intensity at the water surface was derived in such a way that a CAD panel of the rear end of the hull is searched and wave height agrees with the height of the transom in the Z direction. A resistance curve may be obtained easily by using a personal computer. 4 refs., 8 figs.

  19. Method for calculating steady-state waves in an air cushion vehicle. Part 2; Air cushion vehicle no teijo zoha keisanho ni tsuite. 2

    Energy Technology Data Exchange (ETDEWEB)

    Eguchi, T. [Mitsui Engineering and Shipbuilding Co. Ltd., Tokyo (Japan)

    1997-10-01

    Discussions were given on a method to estimate resistance constituents in wave resistance made in an air chamber of an air cushion vehicle (ACV). An orthogonal coordinate system is considered, which uses the center of a hull as the zero point and is made dimensionless by using cushion length. Flow around the ACV is supposed as an ideal flow, whereas speed potential is defined in the flow field. Then, a linear free surface condition is hypothesized on water surface Z = 0. Number and density of waves were used to introduce a condition to be satisfied by the speed potential. A numerical calculation method arranged a blow-out panel on the water surface, and used a panel shift type Rankine source method which satisfies the free surface condition at Z = 0. Cushion pressure distribution becomes a step-like discontinuous function, and mathematical infinity is generated in the differentiation values. Under an assumption that the pressure rises per one panel where pressure jump is present, the distribution was approximated by providing one panel with inclination of the finite quantity therein. Estimation on wave height distribution in the cushion chamber showed a tendency of qualitatively agreeing with the experimental result, but the wave heights shown in the experiment had the average level decreased as it goes toward the rear of the hull. 5 refs., 5 figs.

  20. Method for calculating wave resistance in a catamaran by using a simple panel method; Kanbenna panel ho ni yoru katamaran no zoha teiko keisanho

    Energy Technology Data Exchange (ETDEWEB)

    Kataoka, K. [Kyushu University, Fukuoka (Japan). Faculty of Engineering

    1997-10-01

    This paper describes a method for calculating wave resistance in a catamaran by using a simple panel method. Two Wigley models were put side by side to make a catamaran, speccular images were taken on a face symmetrical in the left and right sides, and only one side (the demi-hull) was used as a region to be calculated. Considering blow-out onto the demi-hull surface and still water surface, a model was constituted, in which discrete vortices were distributed on the demi-hull camber to flow the vortices out to an infinitely distance place from the stern. A free surface condition according to double model linearization by Dawson was derived for this model in terms of numerical analysis. The Kutta`s condition is incorporated when SQCM is used concurrently with the Rankine source method, but not incorporated when not used. Calculations were performed on both conditions. Wave resistance was derived by using pressure integral on the hull surface. It is better to consider the Kutta`s condition when the distance between the demi-hulls is small. However, if the distance is large, or speed is great for the boat length resulting in less interference between the demi-hulls, there is very little difference due to the Kutta`s condition. Difference in the wave shapes causes how waves are made to vary. 11 refs., 8 figs.

  1. Pulse-Wave Analysis of Optic Nerve Head Circulation Is Significantly Correlated with Kidney Function in Patients with and without Chronic Kidney Disease

    Directory of Open Access Journals (Sweden)

    Tomoaki Shiba

    2014-01-01

    Full Text Available Aim. To determine whether there is a significant correlation between the optic nerve head (ONH circulation determined by laser speckle flowgraphy (LSFG and kidney function. Materials. Seventy-one subjects were investigated. The estimated glomerular filtration rate (GFR and serum creatinine, cystatin C, and urinary albumin excretion were measured. The ONH circulation was determined by an analysis of the pulse wave of LSFG, and this parameter was named blowout time (BOT. Chronic kidney disease (CKD was defined to be present when the estimated GFR was <60 mL/min per 1.73 m2. Pearson’s correlation coefficients were used to determine the relationship between the BOT and the kidney function. We also examined whether there were significant differences in all parameters in patients with and without CKD. Results. BOT was significantly correlated with the level of creatinine (r=-0.24, P=0.04, the estimated GFR (r=0.42, P=0.0003, cystatin C (r=-0.29, P=0.01, and urinary albumin excretion (r=-0.29, P=0.01. The BOT level in subjects with CKD was significantly lower than that in subjects without CKD (P=0.002. Conclusion. BOT in ONH by LSFG can detect the organ damage such as kidney dysfunction, CKD.

  2. Rotating Magnetic Structures Associated with a Quasi-circular Ribbon Flare

    Science.gov (United States)

    Li, Haidong; Jiang, Yunchun; Yang, Jiayan; Yang, Bo; Xu, Zhe; Hong, Junchao; Bi, Yi

    2017-02-01

    We present the detection of a small eruption and the associated quasi-circular ribbon flare during the emergence of a bipole occurring on 2015 February 3. Under a fan dome, a sigmoid was rooted in a single magnetic bipole, which was encircled by negative polarity. The nonlinear force-free field extrapolation shows the presence of twisted field lines, which can represent a sigmoid structure. The rotation of the magnetic bipole may cause the twisting of magnetic field lines. An initial brightening appeared at one of the footpoints of the sigmoid, where the positive polarity slides toward a nearby negative polarity field region. The sigmoid displayed an ascending motion and then interacted intensively with the spine-like field. This type of null point reconnection in corona led to a violent blowout jet, and a quasi-circular flare ribbon was also produced. The magnetic emergence and rotational motion are the main contributors to the energy buildup for the flare, while the cancellation and collision might act as a trigger.

  3. Seawater capacitance – a promising proxy for mapping and characterizing drifting hydrocarbon plumes in the deep ocean

    Directory of Open Access Journals (Sweden)

    J. C. Wynn

    2012-08-01

    Full Text Available Hydrocarbons released into the deep ocean are an inevitable consequence of natural seep, seafloor drilling, and leaking wellhead-to-collection-point pipelines. The Macondo 252 (Deepwater Horizon well blowout of 2010 was even larger than the Ixtoc event in the Gulf of Campeche in 1979. History suggests it will not be the last accidental release, as deepwater drilling expands to meet an ever-growing demand. For those who must respond to these sorts of disasters, the first line of action should be to know what is going on. This includes knowing where an oil plume is at any given time, where and how fast it is moving, and how it is evolving. We have experimented in the laboratory with induced polarization as a method to track hydrocarbons in the seawater column and find that finely dispersed oil in seawater gives rise to a large distributed capacitance. This potentially could be used to both map and characterize oil plumes, down to less than 0.1%, drifting and evolving in the deep ocean. A side benefit demonstrated in some earlier sea-trials is that this same approach in modified form can also map certain heavy placer minerals, as well as communication cables, pipelines, and wrecks buried beneath the seafloor.

  4. Microbial transformation of the Deepwater Horizon oil spill – past, present, and future perspectives

    Directory of Open Access Journals (Sweden)

    Nikole E. Kimes

    2014-11-01

    Full Text Available The Deepwater Horizon blowout, which occurred on April 20, 2010, resulted in an unprecedented oil spill. Despite a complex effort to cap the well, oil and gas spewed from the site until July 15, 2010. Although a large proportion of the hydrocarbons was depleted via natural processes and human intervention, a substantial portion of the oil remained unaccounted for and impacted multiple ecosystems throughout the Gulf of Mexico. The depth, duration and magnitude of this spill were unique, raising many questions and concerns regarding the fate of the hydrocarbons released. One major question was whether or not microbial communities would be capable of metabolizing the hydrocarbons, and if so, by what mechanisms and to what extent? In this review, we summarize the microbial response to the oil spill as described by studies performed during the past four years, providing an overview of the different responses associated with the water column, surface waters, deep-sea sediments, and coastal sands/sediments. Collectively, these studies provide evidence that the microbial response to the Deepwater Horizon oil spill was rapid and robust, displaying common attenuation mechanisms optimized for low molecular weight aliphatic and aromatic hydrocarbons. In contrast, the lack of evidence for the attenuation of more recalcitrant hydrocarbon components suggests that future work should focus on both the environmental impact and metabolic fate of recalcitrant compounds, such as oxygenated oil components.

  5. Explosive Chromospheric Evaporation in a Circular-ribbon Flare

    CERN Document Server

    Zhang, Q M; Ning, Z J; Su, Y N; Ji, H S; Guo, Y

    2016-01-01

    In this paper, we report our multiwavelength observations of the C4.2 circular-ribbon flare in active region (AR) 12434 on 2015 October 16. The short-lived flare was associated with positive magnetic polarities and a negative polarity inside, as revealed by the photospheric line-of-sight magnetograms. Such magnetic pattern is strongly indicative of a magnetic null point and spine-fan configuration in the corona. The flare was triggered by the eruption of a mini-filament residing in the AR, which produced the inner flare ribbon (IFR) and the southern part of a closed circular flare ribbon (CFR). When the eruptive filament reached the null point, it triggered null point magnetic reconnection with the ambient open field and generated the bright CFR and a blowout jet. Raster observations of the \\textit{Interface Region Imaging Spectrograph} (\\textit{IRIS}) show plasma upflow at speed of 35$-$120 km s$^{-1}$ in the Fe {\\sc xxi} 1354.09 {\\AA} line ($\\log T\\approx7.05$) and downflow at speed of 10$-$60 km s$^{-1}$ i...

  6. Optimisation of dispersion parameters of Gaussian plume model for CO₂ dispersion.

    Science.gov (United States)

    Liu, Xiong; Godbole, Ajit; Lu, Cheng; Michal, Guillaume; Venton, Philip

    2015-11-01

    The carbon capture and storage (CCS) and enhanced oil recovery (EOR) projects entail the possibility of accidental release of carbon dioxide (CO2) into the atmosphere. To quantify the spread of CO2 following such release, the 'Gaussian' dispersion model is often used to estimate the resulting CO2 concentration levels in the surroundings. The Gaussian model enables quick estimates of the concentration levels. However, the traditionally recommended values of the 'dispersion parameters' in the Gaussian model may not be directly applicable to CO2 dispersion. This paper presents an optimisation technique to obtain the dispersion parameters in order to achieve a quick estimation of CO2 concentration levels in the atmosphere following CO2 blowouts. The optimised dispersion parameters enable the Gaussian model to produce quick estimates of CO2 concentration levels, precluding the necessity to set up and run much more complicated models. Computational fluid dynamics (CFD) models were employed to produce reference CO2 dispersion profiles in various atmospheric stability classes (ASC), different 'source strengths' and degrees of ground roughness. The performance of the CFD models was validated against the 'Kit Fox' field measurements, involving dispersion over a flat horizontal terrain, both with low and high roughness regions. An optimisation model employing a genetic algorithm (GA) to determine the best dispersion parameters in the Gaussian plume model was set up. Optimum values of the dispersion parameters for different ASCs that can be used in the Gaussian plume model for predicting CO2 dispersion were obtained.

  7. Orbital floor reconstruction with poly-L/D-lactide implants: clinical, radiological and immunohistochemical study in sheep.

    Science.gov (United States)

    Kontio, R; Suuronen, R; Konttinen, Y T; Hallikainen, D; Lindqvist, C; Kommonen, B; Kellomäki, M; Kylmä, T; Virtanen, I; Laine, P

    2004-06-01

    In this study the reconstruction capacity of orbital wall in sheep was evaluated when poly-L/D-lactide (PLDLA96) implants were used for large blow-out defects in 18 sheep. The contralateral side, where the defects healed spontaneously, served as controls. The follow-up was 12, 16, 22 and 36 weeks. Healing was evaluated clinically, radiologically, histologically and immunohistochemically. Physiochemical properties of the implants were also studied. At first, the implants were surrounded by elastic capsules, which gradually ossified. At 36 weeks, 60% were still visible and deformed but surrounded by bone. Light microscopy revealed a low grade inflammatory reaction. Expression of Tn-c and cFn was intense throughout the study. Shear strength decreased gradually and was not measurable after 16 weeks. Crystallinity increased steadily from 1.5 to 29.30% and molecular weight decreased from 49,000 to 4186. In CT, the final bony defect was smaller in the reconstructed sides than in the controls. Based on this study it can be concluded that PLDLA96 implant provokes a local inflammation, which does not prevent bone healing. The deformation of the implant, however, indicates that this PLDLA96 plate is not suitable for orbital floor reconstruction.

  8. Meteorite search in the deflation basins in Lea County, New Mexico and Winkler County, Texas, USA: Discovery of Lea County 003 (H4)

    Energy Technology Data Exchange (ETDEWEB)

    Mikouchi, T; Buchanan, P C; Zolensky, M E; Welten, K C; Hutchison, R; Hutchison, M

    2000-01-14

    During the past few decades great numbers of meteorites have been recovered from the ice accumulation zones of Antarctica and from the vast Sahara. Although these two great deserts are the two most productive areas, the Southern High Plains in USA (New Mexico and Texas) and Nullarbor Plain, Western Australia have great potential for meteorite recovery. The number of meteorite finds from Roosevelt County, New Mexico alone exceeds 100 in only approximately 11 km{sup 2} area. Most meteorites from this area have been found on the floors of active deflation basins (blowouts) that have been excavated from a mantle of sand dunes. This area has no apparent fluvial or permafrost activity within the last 50,000 years, suggesting that only prevailing winds and natural aridity aid in the concentration and preservation of meteorites. The authors investigated these deflation surfaces in Lea County (the SE corner of New Mexico) and neighboring Winkler County, Texas following a prior search in this area which found two chondrites. They found a tiny H4 chondrite in this search and here they report its mineralogy and petrology along with preliminary data on its exposure history.

  9. Posttraumatic Orbital Emphysema: A Numerical Model

    Directory of Open Access Journals (Sweden)

    Andrzej Skorek

    2014-01-01

    Full Text Available Orbital emphysema is a common symptom accompanying orbital fracture. The pathomechanism is still not recognized and the usually assumed cause, elevated pressure in the upper airways connected with sneezing or coughing, does not always contribute to the occurrence of this type of fracture. Observations based on the finite model (simulating blowout type fracture of the deformations of the inferior orbital wall after a strike in its lower rim. Authors created a computer numeric model of the orbit with specified features—thickness and resilience modulus. During simulation an evenly spread 14400 N force was applied to the nodular points in the inferior rim (the maximal value not causing cracking of the outer rim, but only ruptures in the inferior wall. The observation was made from 1·10-3 to 1·10-2 second after a strike. Right after a strike dislocations of the inferior orbital wall toward the maxillary sinus were observed. Afterwards a retrograde wave of the dislocation of the inferior wall toward the orbit was noticed. Overall dislocation amplitude reached about 6 mm. Based on a numeric model of the orbit submitted to a strike in the inferior wall an existence of a retrograde shock wave causing orbital emphysema has been found.

  10. Palaeoclimatic considerations of talus flatirons and aeolian deposits in Northern Fuerteventura volcanic island (Canary Islands, Spain)

    Science.gov (United States)

    Gutiérrez-Elorza, Mateo; Lucha, Pedro; Gracia, F.-Javier; Desir, Gloria; Marín, Cinta; Petit-Maire, Nicole

    2013-09-01

    Fuerteventura volcanic island has been subject to considerable aeolian activity since the Late Pleistocene. The aeolian record includes inactive aeolian deposits with interbedded entisols, whose age by OSL dating ranges between 46 and 26 ky BP. The Corralejo active dune field, where sand sheets, nebkhas, coppice dunes, blowouts, barchans and transverse dunes have been described, constitutes a more recent Aeolian deposit. Here the age is about 14 ky BP. On Fuerteventura Island aeolian dust has been deposited on valleys and slopes. This last type of accumulation has been affected by gully incision, producing talus flatirons. Samples taken on the apex of these palaeo-slopes indicate an OSL age of 30 and 50 ky BP. A palaeoclimatic succession has been interpreted during which a prevailing arid period took place in OIS 4, with the accumulation of aeolian dust. A humid period occurred in OIS 2, during which slopes were dissected and formed talus flatirons. An arid period about 14 ky BP gave rise to the Corralejo dune field, which has continued until present with slight climatic oscillations.

  11. Taming of a Wild Research Well in Yellowstone National Park during November 1992

    Science.gov (United States)

    Fournier, Robert O.; Moore, Michael M.

    2008-01-01

    Much of our current understanding of Yellowstone's geothermal areas comes from research drilling by the USGS during 1967 and 1968. Thirteen wells were drilled in thermal areas around the park. Scientists collected waters and rocks, measured temperatures and pressures and performed other tests to characterize the shallow subsurface at Yellowstone. Most wells were plugged and abandoned, but a few were left open for future scientific tests and sampling. One of those wells, the Y8, was located at Biscuit Basin, 2 miles north of Old Faithful. In November 1992, a valve at the ground surface failed, leading to a blowout, an uncontrolled eruption of steam and hot water. The USGS and Yellowstone National Park worked with a drilling contractor to control the flow and plug the well. The lead scientist, Robert Fournier, used video taken by the drilling contractor, Tonto Services, to create this fascinating 28-minute-long film. It is followed by a short news story by CNN, also from November 1992. Fifteen years later, we felt that the video was of sufficient scientific and historical interest that it was worth publishing as a USGS Open-file report, where it can be accessed into the future. Enjoy!

  12. 英语教育在越南

    Institute of Scientific and Technical Information of China (English)

    刘婕

    2011-01-01

    The demand of people with sufficient English ability has encountered a blowout after Vietnam adopted open policy in 1986. Due to her complex contemporary history, English education in Vietnam started late, facing problems such as low English education rat%越南在1986年革新开放后对英语人才的需求量呈井喷式增长,但由于复杂的历史原因,越南的英语教育起步晚,面临着普及率低、英语课程设置不科学和英语教员供应紧张等问题。本文从英语在越南的发展历史入手,根据越南英语的发展现状,分析了当代越南英语教育所面临的问题,并给出解决建议,为中越英语教育对比研究提供参照。

  13. Persistent impacts to the deep soft-bottom benthos one year after the Deepwater Horizon event.

    Science.gov (United States)

    Montagna, Paul A; Baguley, Jeffrey G; Cooksey, Cynthia; Hyland, Jeffrey L

    2017-03-01

    In fall 2010, several months after the Deepwater Horizon blowout was capped, zones of moderate and severe impacts to deep-sea, soft-bottom benthos were identified that together extended over an area of 172 km(2) . A subset of stations sampled in 2010 was resampled in May and June 2011, 10 to 11 months after the event, to determine whether the identified adverse effects were persisting. The design compared 20 stations from the combined moderate and severe impact zone to 12 stations in the reference zone that were sampled in both years. There were no statistically significant differences in contaminant concentrations between the impact and nonimpact zones from 2010 to 2011, which indicates contaminants persisted after 1 y. Whereas there were some signs of recovery in 2011 (particularly for the meiofauna abundance and diversity), there was evidence of persistent, statistically significant impacts to both macrofauna and meiofauna community structure. Macrofaunal taxa richness and diversity in 2011 were still 22.8% and 35.9% less, respectively, in the entire impact zone than in the surrounding nonimpact area, and meiofaunal richness was 28.5% less in the entire impact zone than in the surrounding area. The persistence of significant biodiversity losses and community structure change nearly 1 y after the wellhead was capped indicates that full recovery had yet to have occurred in 2011. Integr Environ Assess Manag 2017;13:342-351. © 2016 SETAC.

  14. Research of Tacit Knowledge Mining in the Resource Integration Process%资源整合过程中隐性知识挖掘研究

    Institute of Scientific and Technical Information of China (English)

    由磊; 刘淑梅

    2012-01-01

    信息时代背景下知识在各领域中起到主导作用,所以在多种资源整合的过程中,知识的整合是非常重要的一部分内容。隐性知识是知识的核心部分,更具价值,但它的显性化过程面临诸多困难。微博的"井喷式"发展是其自身特点适应时代需要的结果,将微博的各种特点与隐性知识的挖掘研究相结合,以此找到一条隐性知识显性化的新思路。%Knowledge plays a leading role in the information age,the integration of knowledge is very important part in the integration of a variety of resources.Tacit knowledge is the core part of knowledge and more valuable.But it faces many difficulties in undergoing process.The "blowout type" development of the micro blogging is the result of its own features suited to the needs of the times.New ideas can be found for the explicitation of tacit knowledge by the integration of the research of the various characteristics of the micro blogging and the mining of tacit knowledge.

  15. Research on the Impact of Big Data on Marketing%大数据对市场营销的冲击研究

    Institute of Scientific and Technical Information of China (English)

    王旭; 罗巍

    2016-01-01

    基于当前全球数据量“井喷式”增长所形成的大数据现象,研究显示大数据促使消费行为更加理性、更有个性和幂律分布;营销决策仰仗数据驱动,关注实时处理及分析;营销战略注重协同发展,开展精准定位营销;营销要素发生革命性变革:产品按人定制,渠道加速缩短,价格透明度提高,促销倚重移动互联。%Based on the phenomenon of big data which formed by current global data 'blowout' growth, the research shows that large data to promote consumer behavior more rational,more personality and power law distribution;Marketing decisions rely on data driven,focus on real-time processing and analysis;Marketing strategy to focus on collaborative development,to carry out precision positioning marketing;Marketing elements of revolutionary change: product according to the custom, channel shortening,increased price transparency,promotion rely on mobile Internet.

  16. Emissions and properties of Bio-oil and Natural Gas Co-combustion in a Pilot Stabilised Swirl Burner

    Science.gov (United States)

    Kowalewski, Dylan

    Fast pyrolysis oil, or bio-oil, has been investigated to replace traditional fossil fuels in industrial burners. However, flame stability is a challenge due to its high water content. In order to address its instability, bio-oil was co-fired with natural gas in a lab scale 10kW swirl burner at energy ratios from 0% bio-oil to 80% bio-oil. To evaluate the combustion, flame shape, exhaust and particulate emissions, temperatures, as well as infrared emission were monitored. As the bio-oil energy fraction increased, NO emissions increased due to the nitrogen content of bio-oil. CO and particulate emissions increased likely due to carbonaceous residue exiting the combustion zone. Unburnt Hydrocarbon (UHC) emissions increased rapidly as combustion became poor at 60-80% bio-oil energy. The temperature and infrared output decreased with more bio-oil energy. The natural gas proved to be effective at anchoring the bio-oil flame to the nozzle, decreasing instances of extinction or blowout.

  17. CONTROL OF GAS EMISSION AT COAL FACE IN CHINA

    Institute of Scientific and Technical Information of China (English)

    俞启香; 付建华

    1991-01-01

    All the underground coal mines in China are gassy mines. The gas emission at coal face increasingly grows with the increase of working depth and coal output,for example,the gas emission at a full mechanized coal face of mine No.2 at Yongquan with a daily output of 2,000t/d is up to 66--72m3/min. Special gas emission phenomena such as gas blowout, gas and coal outburst etc. have occurred at some faces, which threatens the safe production of face, obstructs the growth of productivity and limits the full play of mechanized equipment. In this paper, gas at face is divided, according to its origin, into three constituents, namely, coming from the coal wall, mined coal and goaf; and a formula for calculation is given. Also, the characteristics of the variation of gas emission at coal face, and thesinfluence of mining sequence of a group of seams and supplied air quantity on the gas emission are discussed. Furthermore, based on the regularity of gas emission st coal face from the above three sources, and on the experiences of years, three principles on controlling gas emission at coal face are presented, that are managing the gas on classification basis, harnessing each source separately and comprehensive prevention and control. Finally, technical measures for prevention and treatment of the accumulation of gas in the upper corner of face, at the working place of coal-winning machine and in the bottom trough of conveyor are introduced.

  18. An oil spill surveillance program for Lake Pontchartrain.

    Science.gov (United States)

    Boyd, Ezra; Pereira, Joao F; Retana, Gabriel; Baker, Andy; Lopez, John; McCorquodale, Alex

    2013-01-01

    This article describes an oil spill surveillance strategy implemented in response to BP's 2010 MC252 oil well blowout in the Gulf of Mexico. A three-pronged strategy consisted of Geographic Information System (GIS) monitoring of the surface slick, hydrodynamic modeling of the potential movement of the slick within the Basin, and weekly field reconnaissance. Our analysis was completed in near real time during the event and the results and predictions helped local responders minimize oiling impacts in Lake Pontchartrain. No prior planning was undertaken before this crisis response, and this article reports our support activities as they happened. For the GIS component, a remote sensing derived surface slick outline layer was obtained to produce near daily maps showing the slick's proximity to Lake Pontchartrain along with weather conditions and deployed response assets. This regular monitoring of the slicks' location was complemented by hydrodynamic numerical modeling that simulated the currents that determined the trajectories of oil particles. These data were ground-truthed through weekly reconnaissance trips that assessed the potential routes of oil penetration into Lake Pontchartrain for the presence of sheen, tarballs, and other oil constituents. Despite the ad hoc design and on-the-fly implementation, these three assessments provided consistent and actionable information.

  19. The Skill and the Effect of Supply Calcium Nutrition Liquid in Fruit Trunk%果树树干补钙技术与效果

    Institute of Scientific and Technical Information of China (English)

    童风; 李翠兰

    2000-01-01

    Research result that the art and effect of passing inject supply calcium nutrition liquid in tree trunk of fruit indicate.The supply nutrition liquid of calcium with different time and different dosage were brought different effect.The skill could be add calcium content in fruit,prolong store time,add weight single fruit,prevent fruit blowout of pomelo,cherry etc,and it had safety,good effect,easy operating,low price and wide application.%通过对果树树干进行注射补钙技术与效果的研究结果表明:补钙时期、补钙剂量不同,其产生的效果各异。利用树干注射补钙技术可增加果实中的钙含量,延长果品贮藏期,增加果实单果重,防止柚子、樱桃等果实的裂果病。该技术具有使用安全、补钙效果好、易操作,成本低、应用范围广等特点。

  20. Energy audit workbook for bakeries

    Energy Technology Data Exchange (ETDEWEB)

    1978-09-01

    In a typical bakery, it is possible to save as much as 15 percent of utility costs through common-sense actions without any appreciable capital expenditure. Many bakery operators do not realize that it might be possible to close the dampers down on the oven. Most oven dampers can be closed down until condensation or fume blowout occurs. One bakery realized a savings of $13,000 per year by closing down the oven dampers to the minimum. You should be able to close down the dampers without incurring any initial cost. Another energy-saving measure that is quite practical to the baking industry is preheating the combustion air to the oven burners. Providing hot air for combustion is much more efficient than drawing cold air from the surroundings. To preheat the combustion air several bakeries have installed heat exchangers in the exhaust gases. Energy savings of 3 to 4 percent are feasible. Energy-saving measures in the lighting system and HVAC system are indicated.

  1. Assessment of sediment hydrocarbon contamination from the 2009 Montara oil blow out in the Timor Sea.

    Science.gov (United States)

    Burns, Kathryn A; Jones, Ross

    2016-04-01

    In August 2009, a blowout of the Montara H1 well 260 km off the northwest coast of Australia resulted in the uncontrolled release of about 4.7 M L of light crude oil and gaseous hydrocarbons into the Timor Sea. Over the 74 day period of the spill, the oil remained offshore and did not result in shoreline incidents on the Australia mainland. At various times slicks were sighted over a 90,000 km(2) area, forming a layer of oil which was tracked by airplanes and satellites but the slicks typically remained within 35 km of the well head platform and were treated with 183,000 L of dispersants. The shelf area where the spill occurred is shallow (100-200 m) and includes off shore emergent reefs and cays and submerged banks and shoals. This study describes the increased inputs of oil to the system and assesses the environmental impact. Concentrations of hydrocarbon in the sediment at the time of survey were very low (total aromatic hydrocarbons (PAHs) ranged from 0.04 to 31 ng g(-1)) and were orders of magnitude lower than concentrations at which biological effects would be expected.

  2. The SHARDDS survey: first resolved image of the HD114082 debris disk in Lower Centaurus Crux with SPHERE

    CERN Document Server

    Wahhaj, Zahed; Kennedy, Grant; Ertel, Steve; Matra, Luca; Boccaletti, Anthony; del Burgo, Carlos; Wyatt, Mark; Pinte, Christophe; Lagrange, Anne Marie; Absil, Olivier; Choquet, Elodie; Gonzalez, Carlos Gomez; Kobayashii, Hiroshi; Mawet, Dimitri; Mouillet, David; Pueyo, Laurent; Dent, William R F; Augereau, Jean-Charles; Girard, Julien

    2016-01-01

    We present the first resolved image of the debris disk around the 16+/-8 Myr old star, HD 114082. The observation was made in the H-band using the SPHERE instrument. The star is at a distance of 92+/-6 pc in the Lower Centaurus Crux association. Using a Markov Chain Monte Carlo analysis, we determined that the debris is likely in the form of a dust ring with an inner edge of 27.7+2.8/-3.5 au, position angle -74+0.5/-1.5 deg, and an inclination with respect to the line of sight of 6.7+3.8/-0.4 deg. The disk imaged in scattered light has a surface density declining with radius like ~r^(-4), steeper than expected for grain blowout by radiation pressure. We find only marginal evidence (2 sigma) of eccentricity, and rule out planets more massive than 1.0 Mjup orbiting within 1 au of the ring's inner edge, since such a planet would have disrupted the disk. The disk has roughly the same fractional disk luminosity (Ldisk/L*=3.3x10^(-3)) as HR4796A and Beta Pictoris, however it was not detected by previous instrument ...

  3. CFD predictions of LBO limits for aero-engine combustors using fuel iterative approximation

    Institute of Scientific and Technical Information of China (English)

    Hu Bin; Huang Yong; Wang Fang; Xie Fa

    2013-01-01

    Lean blow-out (LBO) is critical to operational performance of combustion systems in propulsion and power generation.Current predictive tools for LBO limits are based on decadesold empirical correlations that have limited applicability for modern combustor designs.According to the Lefebvre's model for LBO and classical perfect stirred reactor (PSR) concept,a load parameter (LP) is proposed for LBO analysis of aero-engine combustors in this paper.The parameters contained in load parameter are all estimated from the non-reacting flow field of a combustor that is obtained by numerical simulation.Additionally,based on the load parameter,a method of fuel iterative approximation (FIA) is proposed to predict the LBO limit of the combustor.Compared with experimental data for 19 combustors,it is found that load parameter can represent the actual combustion load of the combustor near LBO and have good relativity with LBO fuel/air ratio (FAR).The LBO FAR obtained by FIA shows good agreement with experimental data,the maximum prediction uncertainty of FIA is about ± 17.5%.Because only the non-reacting flow is simulated,the time cost of the LBO limit prediction using FIA is relatively low (about 6 h for one combustor with computer equipment of CPU 2.66 GHz × 4 and 4 GB memory),showing that FIA is reliable and efficient to be used for practical applications.

  4. Surgical Management of Subaxial Cervical Spine Trauma: A Case Report

    Directory of Open Access Journals (Sweden)

    Hasan Emre Aydın

    2015-04-01

    Full Text Available These days, as a consequence of the improvement in technology and increase in the use of motor vehicles, spine injuries have become common. Spine traumas, which often occur after motor vehicle accidents, are observed mostly in cervical regions, particularly in the subaxial cervical region, which is also known as the subcervical region, and neurological damage occurs in 70% of the patients. Despite still being controversial, the common ranging for neurological evaluation is the American Spinal Injury Association ranging, which includes the motor and sensory loss and accordingly, the impairment rate. In subaxial cervical traumas, acute neurological deterioration is an indication and therefore requires urgent surgical treatment. The choice of anterior or posterior approach substantially depends on the traumatization mechanism, affected tissues, and neurological deterioration occurring after. The state of patient and instability are the most two important factors affecting the treatment decision. Although the anterior approach is accepted as a routinely available and easily applicable surgical technique, it lacks in the burst fractures involving the three colons, which shows a stabilization disorder. The anterior plate screw technique and posterior lateral mass screw application applied in our clinic are reviewed in literature and are discussed in two cases. Although the best clinical results are achieved in cases where only anterior surgery is performed and in cases where instability is excessive, in unstable compression and blow-out fractures, even if neurological deficit and three colon involvement are not observed in the patient, the requirement of posterior fusion is observed.

  5. Assessment of non-destructive testing of well casing,, cement and cement bond in high temperature wells

    Energy Technology Data Exchange (ETDEWEB)

    Knutson, C K; Boardman, C R

    1979-01-01

    Because of the difficulty in bringing geothermal well blowouts under control, any indication of a casing/cement problem should be expeditiously evaluated and solved. There are currently no high temperature cement bond and casing integrity logging systems for geothermal wells with maximum temperatures in excess of 500/sup 0/F. The market is currently insufficient to warrannt the private investment necessary to develop tools and cables capable of withstanding high temperatures. It is concluded that a DOE-funded development program is required to assure that diagnostic tools are available in the interim until geothermal resource development activities are of sufficient magnitude to support developmental work on high temperature casing/cement logging capabilities by industry. This program should be similar to and complement the current DOE program for development of reservoir evaluation logging capabilities for hot wells. The appendices contain annotated bibliographies on the following: high temperature logging in general, cement integrity testing, cosing integrity testing, casing and cement failures, and special and protective treatment techniques. Also included are composite listing of references in alphabetical order by senior author.

  6. Vulnerability Assessment of a Coastal Dune System at São Francisco do Sul Island, Santa Catarina, Brazil

    Science.gov (United States)

    Alquini, Fernanda; Bertoni, Duccio; Sarti, Giovanni; Ciccarelli, Daniela; Pozzebon, Alessandro; Ferreira de Melo Júnior, João Carlos; Voos Vieira, Celso

    2016-10-01

    In this paper a Coastal Dune Vulnerability Index (CDVI) has been applied on a beach located in the eastern side of Sao Francisco do Sul Island (Brazil). The aim of this study is to assess the vulnerability of a coastal dune system and to identify the areas that result most sensitive to environmental changes. The CDVI has been applied along six transects traced out on two sectors that have been selected based on dune characteristics: Zone A is characterized by well developed parabolic dunes, whereas Zone B is characterized by transverse dunes. The analysis involved 51 quantitative and qualitative variables, divided into five groups: geomorphological dune system condition, marine influence, Aeolian effect, vegetation condition and human effect. The total CDVI was computed as the unweighted average of the partial vulnerability indices. In summary, the total vulnerability can be classified as medium: the geomorphological factor must be monitored at Grande beach, in particular the blowouts in Zone A and the frontal dune retreat in Zone B. The results of the study confirm that the management of coastal areas might be improved using a tool such as the CDVI, which can be easily applied on a regular basis to take under control the factors that mostly affect the evolution of the site.

  7. Oil spill modeling in the southeastern Mediterranean Sea in support of accelerated offshore oil and gas exploration

    Science.gov (United States)

    Brenner, Steve

    2015-12-01

    Since the discovery of major reserves in the Israeli exclusive economic zone (EEZ) 6 years ago, exploration and drilling for natural gas and oil have proceeded at an accelerated pace. As part of the licensing procedure for drilling, an environmental impact assessment and an emergency response plan must be presented to the authorities, which include several prespecified oil spill simulations. In this study, the MEDSLIK oil spill model has been applied for this purpose. The model accounts for time-dependent advection, dispersion, and physiochemical weathering of the surface slick. It is driven by currents produced by high-resolution dynamic downscaling of ocean reanalysis data and winds extracted from global atmospheric analyses. Worst case scenarios based on 30-day well blowouts under four sets of environmental conditions were simulated for wells located at 140, 70, and 20 km off the coast of central Israel. For the well furthest from the coast, the amount of oil remaining in the surface slick always exceeds the amount deposited on the coast. For the mid-distance well, the cases were evenly split. For the well closest to the coast, coastal deposition always exceeds the oil remaining in the slick. Additional simulations with the wind switched off helped highlight the importance of the wind in evaporation of the oil and in transporting the slick toward the southeastern coast.

  8. Dust production in debris discs: constraints on the smallest grains

    CERN Document Server

    Thebault, Philippe

    2016-01-01

    The surface energy constraint puts a limit on the smallest fragment $s_{surf}$ that can be produced after a collision. Based on analytical considerations, this mechanism has been recently identified as been potentially able to prevent the production of small dust grains in debris discs and cut off their size distribution at sizes larger than the blow-out size. We numerically investigate the importance of this effect to find under which conditions it can leave a signature in the small-size end of a disc's particle size distribution (PSD). An important part of this work is to map out, in a disc at steady-state, what is the most likely collisional origin for micron-sized grains, in terms of the sizes of their collisional progenitors. We implement, for the first time, the surface energy constraint into a collisional evolution code. We consider a debris disc extending from 50 to 100AU and 2 different stellar types. We also consider two levels of stirring in the disc: dynamically "hot" (e=0.075) and "cold" (e=0.01)...

  9. Current loops, phase transitions, and the Higgs mechanism in Josephson-coupled multicomponent superconductors

    Science.gov (United States)

    Galteland, Peder Notto; Sudbø, Asle

    2016-08-01

    The N -component London U (1 ) superconductor is expressed in terms of integer-valued supercurrents. We show that the inclusion of interband Josephson couplings introduces monopoles in the current fields, which convert the phase transitions of the charge-neutral sector to crossovers. The monopoles only couple to the neutral sector, and leave the phase transition of the charged sector intact. The remnant noncritical fluctuations in the neutral sector influence the one remaining phase transition in the charged sector, and may alter this phase transition from a 3 D X Y inverted phase transition into a first-order phase transition depending on what the values of the gauge charge and the intercomponent Josephson coupling are. This preemptive effect becomes more pronounced with increasing number of components N , since the number of charge-neutral fluctuating modes that can influence the charged sector increases with N . We also calculate the gauge-field correlator, and by extension the Higgs mass, in terms of current-current correlators. We show that the onset of the Higgs mass of the photon (Meissner effect) is given in terms of a current loop blowout associated with going into the superconducting state as the temperature of the system is lowered.

  10. Application of inertial navigation to wellbore positional surveying

    Energy Technology Data Exchange (ETDEWEB)

    Watts, A.C.

    1982-06-01

    There is an increasing need for higher accuracy in wellbore directional and positional surveying than is currently available using conventional techniques. Among the factors contributing to this need are closed interspacing of wells particularly from offshore platforms, deeper and more highly deviated wells, smaller target formations and the requirement for rapid drilling of relief wells in the case of blowouts. The application of inertial navigation system (INS) of suitable size and cost for this type of application is not inherently accurate enough to offer significant improvements in well-surveying accuracy. Techniques to improve accuracy are, in general, based on the fact that the dynamics associated with the propagation of the navigator errors are very well known. Inertial systems are routinely aided using external data from a number of sources. Such aiding may take the form of an external position or velocity measurement which is compared to the position or velocity indicated by the navigator. Kalman filter theory provides a convenient formulation for generation of a minimum variance estimate of the state vector of a linear system. The theory may be extended to the nonlinear case through the use of linearization about a state trajectory. This approach is currently seeing wide use in aiding of inertial navigation systems. The approach proposed here would use the Kalman filter formulation for estimation of the INS errors and updating of the navigator. This formulation also provides a structure for estimation of various instrument parameters which should improve system performance.

  11. Seawater capacitance – a promising proxy for mapping and characterizing drifting hydrocarbon plumes in the deep ocean

    Directory of Open Access Journals (Sweden)

    J. A. Fleming

    2012-12-01

    Full Text Available Hydrocarbons released into the deep ocean are an inevitable consequence of natural seep, seafloor drilling, and leaking wellhead-to-collection-point pipelines. The Macondo 252 (Deepwater Horizon well blowout of 2010 was even larger than the Ixtoc event in the Gulf of Campeche in 1979. History suggests it will not be the last accidental release, as deepwater drilling expands to meet an ever-growing demand. For those who must respond to this kind of disaster, the first line of action should be to know what is going on. This includes knowing where an oil plume is at any given time, where and how fast it is moving, and how it is evolving or degrading. We have experimented in the laboratory with induced polarization as a method to track hydrocarbons in the seawater column and find that finely dispersed oil in seawater gives rise to a large distributed capacitance. From previous sea trials, we infer this could potentially be used to both map and characterize oil plumes, down to a ratio of less than 0.001 oil-to-seawater, drifting and evolving in the deep ocean. A side benefit demonstrated in some earlier sea trials is that this same approach in modified form can also map certain heavy placer minerals, as well as communication cables, pipelines, and wrecks buried beneath the seafloor.

  12. A Non-radial Eruption in a Quadrupolar Magnetic Configuration with a Coronal Null

    Science.gov (United States)

    Sun, Xudong; Hoeksema, J. Todd; Liu, Yang; Chen, Qingrong; Hayashi, Keiji

    2012-10-01

    We report one of the several homologous non-radial eruptions from NOAA active region (AR) 11158 that are strongly modulated by the local magnetic field as observed with the Solar Dynamic Observatory. A small bipole emerged in the sunspot complex and subsequently created a quadrupolar flux system. Nonlinear force-free field extrapolation from vector magnetograms reveals its energetic nature: the fast-shearing bipole accumulated ~2 × 1031 erg free energy (10% of AR total) over just one day despite its relatively small magnetic flux (5% of AR total). During the eruption, the ejected plasma followed a highly inclined trajectory, over 60° with respect to the radial direction, forming a jet-like, inverted-Y-shaped structure in its wake. Field extrapolation suggests complicated magnetic connectivity with a coronal null point, which is favorable of reconnection between different flux components in the quadrupolar system. Indeed, multiple pairs of flare ribbons brightened simultaneously, and coronal reconnection signatures appeared near the inferred null. Part of the magnetic setting resembles that of a blowout-type jet; the observed inverted-Y structure likely outlines the open field lines along the separatrix surface. Owing to the asymmetrical photospheric flux distribution, the confining magnetic pressure decreases much faster horizontally than upward. This special field geometry likely guided the non-radial eruption during its initial stage.

  13. A NON-RADIAL ERUPTION IN A QUADRUPOLAR MAGNETIC CONFIGURATION WITH A CORONAL NULL

    Energy Technology Data Exchange (ETDEWEB)

    Sun Xudong; Hoeksema, J. Todd; Liu Yang; Hayashi, Keiji [W. W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305 (United States); Chen Qingrong, E-mail: xudong@sun.stanford.edu [Department of Physics, Stanford University, Stanford, CA 94305 (United States)

    2012-10-01

    We report one of the several homologous non-radial eruptions from NOAA active region (AR) 11158 that are strongly modulated by the local magnetic field as observed with the Solar Dynamic Observatory. A small bipole emerged in the sunspot complex and subsequently created a quadrupolar flux system. Nonlinear force-free field extrapolation from vector magnetograms reveals its energetic nature: the fast-shearing bipole accumulated {approx}2 Multiplication-Sign 10{sup 31} erg free energy (10% of AR total) over just one day despite its relatively small magnetic flux (5% of AR total). During the eruption, the ejected plasma followed a highly inclined trajectory, over 60 Degree-Sign with respect to the radial direction, forming a jet-like, inverted-Y-shaped structure in its wake. Field extrapolation suggests complicated magnetic connectivity with a coronal null point, which is favorable of reconnection between different flux components in the quadrupolar system. Indeed, multiple pairs of flare ribbons brightened simultaneously, and coronal reconnection signatures appeared near the inferred null. Part of the magnetic setting resembles that of a blowout-type jet; the observed inverted-Y structure likely outlines the open field lines along the separatrix surface. Owing to the asymmetrical photospheric flux distribution, the confining magnetic pressure decreases much faster horizontally than upward. This special field geometry likely guided the non-radial eruption during its initial stage.

  14. Shape memory alloy actuated accumulator for ultra-deepwater oil and gas exploration

    Science.gov (United States)

    Patil, Devendra; Song, Gangbing

    2016-04-01

    As offshore oil and gas exploration moves further offshore and into deeper waters to reach hydrocarbon reserves, it is becoming essential for the industry to develop more reliable and efficient hydraulic accumulators to supply pressured hydraulic fluid for various control and actuation operations, such as closing rams of blowout preventers and controlling subsea valves on the seafloor. By utilizing the shape memory effect property of nitinol, which is a type of shape memory alloy (SMA), an innovative SMA actuated hydraulic accumulator prototype has been developed and successfully tested at Smart Materials and Structure Laboratory at the University of Houston. Absence of gas in the developed SMA accumulator prototype makes it immune to hydrostatic head loss caused by water depth and thus reduces the number of accumulators required in deep water operations. Experiments with a feedback control have demonstrated that the proposed SMA actuated accumulator can provide precisely regulated pressurized fluids. Furthermore the potential use of ultracapacitors along with an embedded system to control the electric power supplied to SMA allows this accumulator to be an autonomous device for deployment. The developed SMA accumulator will make deepwater oil extraction systems more compact and cost effective.

  15. Experiments on Self-Guiding Mechanisms of High Power Laser Pulses in a Plasma

    Science.gov (United States)

    Ralph, Joseph; Pak, Arthur; Marsh, Kenneth; Clayton, Christopher; Fang, Fang; Joshi, Chandrashekhar

    2007-11-01

    Recent 3D theory and PIC simulations in the blowout regime, wherein the pondermotive force of laser with a pulse length on the order of a plasma wavelength expels all electrons, has predicted a range of parameter space where stable laser propagation can occur [1]. In this theory, the density depression caused by electron blow out is the dominant mechism responsible for self-guiding. In this paper we examine experimentally and with PIC simulations laser beam guiding of a multi terwatt TiSapphire laser in a supersonic Helium gas jet. Gas jet density was varied from 2*E18 to to 2*E19 and the length of the plasma was varied from 2 to 5 mm using several gas jets with different diameters. Pondermotive and relativistic effects are considerd by varying laser and plasma parameters. Diagnostics include interferometric and Schlieren techniques. Images of the guided mode are taken at the exit of the gas jet. In addition, the forward images were sent to an imaging spectragraph to observe photon deceleration and deceleration [2]. [1] W. Lu, C. Huang, M. Zhou, and M. Tzoufras, F. S. Tsung, W. B. Mori, and T. Katsouleas, Phys. Plasmas 13, 056709 (2006) [2] A. E. Pak, J. E. Ralph, K. A. Marsh , C. E. Clayton, F. Fang and C. Joshi, These Procedings

  16. The Formation and Evolution of Planetary Systems (FEPS): Discovery of an Unusual Debris System Associated with HD 12039

    CERN Document Server

    Hines, D C; Bouwman, J; Hillenbrand, L A; Carpenter, J M; Meyer, M R; Kim, J S; Silverstone, M D; Rodmann, J; Wolf, S; Mamajek, E E; Brooke, T Y; Padgett, D L; Henning, T; Moro-Martin, A; Stobie, E B; Gordon, K D; Morrison, J E; Muzerolle, J; Su, K Y L

    2006-01-01

    We report the discovery of a debris system associated with the $\\sim 30$ Myr old G3/5V star HD 12039 using {\\it Spitzer Space Telescope} observations from 3.6 -- 160$\\mu$m. An observed infrared excess (L$_{\\rm IR}$/L$_{\\ast} = 1\\times10^{-4}$) above the expected photosphere for $\\lambda \\gtrsim 14\\mu$m is fit by thermally emitting material with a color temperature of T$\\sim 110$ K, warmer than the majority of debris disks identified to date around Sun-like stars. The object is not detected at 70$\\mu$m with a 3$\\sigma$ upper limit 6 times the expected photospheric flux. The spectrum of the infrared excess can be explained by warm, optically thin material comprised of blackbody-like grains of size $\\gtrsim 7 \\mu$m that reside in a belt orbiting the star at 4--6 AU. An alternate model dominated by smaller grains, near the blow-out size $a\\sim 0.5\\mu$m, located at 30-40AU is also possible, but requires the dust to have been produced recently since such small grains will be expelled from the system by radiation pr...

  17. [Endoscopic approaches to the orbit].

    Science.gov (United States)

    Cebula, H; Lahlou, A; De Battista, J C; Debry, C; Froelich, S

    2010-01-01

    During the last decade, the use of endoscopic endonasal approaches to the pituitary has increased considerably. The endoscopic endonasal and transantral approaches offer a minimally invasive alternative to the classic transcranial or transconjunctival approaches to the medial aspect of the orbit. The medial wall of the orbit, the orbital apex, and the optic canal can be exposed through a middle meatal antrostomy, an anterior and posterior ethmoidectomy, and a sphenoidotomy. The inferomedial wall of the orbit can be also perfectly visualized through a sublabial antrostomy or an inferior meatal antrostomy. Several reports have described the use of an endoscopic approach for the resection or the biopsy of lesions located on the medial extraconal aspect of the orbit and orbital apex. However, the resection of intraconal lesions is still limited by inadequate instrumentation. Other indications for the endoscopic approach to the orbit are the decompression of the orbit for Graves' ophthalmopathy and traumatic optic neuropathy. However, the optimal management of traumatic optic neuropathy remains very controversial. Endoscopic endonasal decompression of the optic nerve in case of tumor compression could be a more valid indication in combination with radiation therapy. Finally, the endoscopic transantral treatment of blowout fracture of the floor of the orbit is an interesting option that avoids the eyelid or conjunctive incision of traditional approaches. The collaboration between the neurosurgeon and the ENT surgeon is mandatory and reduces the morbidity of the approach. Progress in instrumentation and optical devices will certainly make this approach promising for intraconal tumor of the orbit.

  18. Safe retaining pressures for pressurized tunnel face using nonlinear failure criterion and reliability theory

    Institute of Scientific and Technical Information of China (English)

    YANG Xiao-li; YAO Cong; ZHANG Jia-hua

    2016-01-01

    Based on the active failure mechanism and passive failure mechanism for a pressurized tunnel face, the analytical solutions of the minimum collapse pressure and maximum blowout pressure that could maintain the stability of pressurized tunnel faces were deduced using limit analysis in conjunction with nonlinear failure criterion under the condition of pore water pressure. Due to the objective existence of the parameter randomness of soil, the statistical properties of random variables were determined by the maximum entropy principle, and the Monte Carlo method was employed to calculate the failure probability of a pressurized tunnel. The results show that the randomness of soil parameters exerts great influence on the stability of a pressurized tunnel, which indicates that the research should be done on the topic of determination of statistical distribution for geotechnical parameters and the level of variability. For the failure probability of a pressurized tunnel under multiple failure modes, the corresponding safe retaining pressures and optimal range of safe retaining pressures are calculated by introducing allowable failure probability and minimum allowable failure probability. The results can provide practical use in the pressurized tunnel engineering.

  19. Parsec-scale X-ray Flows in High-mass Star-forming Regions

    CERN Document Server

    Townsley, L K; Montmerle, T; Broos, P; Chu, Y H; Garmire, G; Getman, K

    2004-01-01

    We present Chandra/ACIS images of several high-mass star-forming regions. The massive stellar clusters powering these HII regions are resolved at the arcsecond level into hundreds of stellar sources, similar to those seen in closer young stellar clusters. However, we also detect diffuse X-ray emission on parsec scales that is spatially and spectrally distinct from the point source population. For nearby regions (e.g. M17 and Rosette) the emission is soft, with plasma temperatures less than 10 million degrees, in contrast to what is seen in more distant complexes (e.g. RCW49, W51). This extended emission most likely arises from the fast O-star winds thermalized either by wind-wind collisions or by a termination shock against the surrounding media. We have established that only a small portion of the wind energy and mass appears in the observed diffuse X-ray plasma; in the blister HII regions, we suspect that most of it flows without cooling into the low-density interstellar medium through blow-outs or fissures...

  20. Combustion stability characteristics of the model chamber with various configurations of triplet impinging-jet injectors

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Chae Hoon [Chosun University, Gwangju (Korea, Republic of); Seol, Woo Seok [Korea Aerospace Research Institute, Daejeon (Korea, Republic of); Shibanov, Alexander A. [Research Institute of Chemical Machine Building, Sergiev Posad (Russian Federation)

    2006-06-15

    Combustion stability characteristics in actual full-scale combustion chamber of a rocket engine are investigated by experimental tests with the model (sub-scale) chamber. The present hot-fire tests adopt the combustion chamber with three configurations of triplet impinging-jet injectors such as F-O-O-F, F-O-F, and O-F-O configurations. Combustion stability boundaries are obtained and presented by the parameters of combustion-chamber pressure and mixture (oxidizer/fuel) ratio. From the experimental tests, two instability regions are observed and the pressure oscillations have the similar patterns irrespective of injector configuration. But, the O-F-O injector configuration shows broader upper-instability region than the other configurations. To verify the instability mechanism for the lower and upper instability regions, air-purge acoustic test is conducted and the photograph of the flames is taken. As a result, it is found that the pressure oscillations in the two regions can be characterized by the first impinging point of hydraulic jets and pre-blowout combustion, respectively.

  1. Discovery of extreme [O III] λ5007 Å outflows in high-redshift red quasars

    Science.gov (United States)

    Zakamska, Nadia L.; Hamann, Fred; Pâris, Isabelle; Brandt, W. N.; Greene, Jenny E.; Strauss, Michael A.; Villforth, Carolin; Wylezalek, Dominika; Alexandroff, Rachael M.; Ross, Nicholas P.

    2016-07-01

    Black hole feedback is now a standard component of galaxy formation models. These models predict that the impact of black hole activity on its host galaxy likely peaked at z = 2-3, the epoch of strongest star formation activity and black hole accretion activity in the Universe. We used XSHOOTER on the Very Large Telescope to measure rest-frame optical spectra of four z ˜ 2.5 extremely red quasars with infrared luminosities ˜1047 erg s-1. We present the discovery of very broad (full width at half max = 2600-5000 km s-1), strongly blueshifted (by up to 1500 km s-1) [O III] λ5007 Å emission lines in these objects. In a large sample of type 2 and red quasars, [O III] kinematics are positively correlated with infrared luminosity, and the four objects in our sample are on the extreme end in both [O III] kinematics and infrared luminosity. We estimate that at least 3 per cent of the bolometric luminosity in these objects is being converted into the kinetic power of the observed wind. Photo-ionization estimates suggest that the [O III] emission might be extended on a few kpc scales, which would suggest that the extreme outflow is affecting the entire host galaxy of the quasar. These sources may be the signposts of the most extreme form of quasar feedback at the peak epoch of galaxy formation, and may represent an active `blow-out' phase of quasar evolution.

  2. Pre-flare coronal jet and evolutionary phases of a solar eruptive prominence associated with M1.8 flare: SDO and RHESSI observations

    CERN Document Server

    Joshi, Bhuwan; Veronig, Astrid; Cho, Kyung-Suk

    2016-01-01

    We investigate triggering, activation, and ejection of a solar eruptive prominence that occurred in a multi-polar flux system of active region NOAA 11548 on 2012 August 18 by analyzing data from AIA on board SDO, RHESSI, and EUVI/SECCHI on board STEREO. Prior to the prominence activation, we observed striking coronal activities in the form of a blowout jet which is associated with rapid eruption of a cool flux rope. Further, the jet-associated flux rope eruption underwent splitting and rotation during its outward expansion. These coronal activities are followed by the prominence activation during which it slowly rises with a speed of ~12 km/s while the region below the prominence emits gradually varying EUV and thermal X-ray emissions. From these observations, we propose that the prominence eruption is a complex, multi-step phenomenon in which a combination of internal (tether-cutting reconnection) and external (i.e., pre-eruption coronal activities) processes are involved. The prominence underwent catastroph...

  3. Retrospective examination of geothermal environmental assessments

    Energy Technology Data Exchange (ETDEWEB)

    Webb, J.W.; Eddlemon, G.K.; Reed, A.W.

    1984-03-01

    Since 1976, the Department of Energy (DOE) has supported a variety of programs and projects dealing with the exploration, development, and utilization of geothermal energy. This report presents an overview of the environmental impacts associated with these efforts. Impacts that were predicted in the environmental analyses prepared for the programs and projects are reviewed and summarized, along with measures that were recommended to mitigate these impacts. Also, for those projects that have gone forward, actual impacts and implemented mitigation measures are reported, based on telephone interviews with DOE and project personnel. An accident involving spills of geothermal fluids was the major environmental concern associated with geothermal development. Other important considerations included noise from drilling and production, emissions of H/sub 2/S and cooling tower drift, disposal of solid waste (e.g., from H/sub 2/S control), and the cumulative effects of geothermal development on land use and ecosystems. Mitigation measures were frequently recommended and implemented in conjunction with noise reduction; drift elimination; reduction of fugitive dust, erosion, and sedimentation; blowout prevention; and retention of wastes and spills. Monitoring to resolve uncertainties was often implemented to detect induced seismicity and subsidence, noise, drift deposition, concentrations of air and water pollutants, and effects on groundwater. The document contains an appendix, based on these findings, which outlines major environmental concerns, mitigation measures, and monitoring requirements associated with geothermal energy. Sources of information on various potential impacts are also listed.

  4. Synthetic Modeling of Autonomous Learning with a Chaotic Neural Network

    Science.gov (United States)

    Funabashi, Masatoshi

    We investigate the possible role of intermittent chaotic dynamics called chaotic itinerancy, in interaction with nonsupervised learnings that reinforce and weaken the neural connection depending on the dynamics itself. We first performed hierarchical stability analysis of the Chaotic Neural Network model (CNN) according to the structure of invariant subspaces. Irregular transition between two attractor ruins with positive maximum Lyapunov exponent was triggered by the blowout bifurcation of the attractor spaces, and was associated with riddled basins structure. We secondly modeled two autonomous learnings, Hebbian learning and spike-timing-dependent plasticity (STDP) rule, and simulated the effect on the chaotic itinerancy state of CNN. Hebbian learning increased the residence time on attractor ruins, and produced novel attractors in the minimum higher-dimensional subspace. It also augmented the neuronal synchrony and established the uniform modularity in chaotic itinerancy. STDP rule reduced the residence time on attractor ruins, and brought a wide range of periodicity in emerged attractors, possibly including strange attractors. Both learning rules selectively destroyed and preserved the specific invariant subspaces, depending on the neuron synchrony of the subspace where the orbits are situated. Computational rationale of the autonomous learning is discussed in connectionist perspective.

  5. Safety Management of Oil and Gas Drilling of High Sulfur Content in Northeastern Sichuan Region%川东北地区高含硫油气井钻井安全管理

    Institute of Scientific and Technical Information of China (English)

    邹汉杰; 李和焱

    2012-01-01

    Eastern Sichuan regions ate based on producing natural gas, which exist in the characteristics, such as high pressure, high sulfur content and deep gas layer burying, coupled with great difficulty of well control technology of oil drilling, which is called the most construction risk in China's onshore oil and gas drilling. Hydrogen sulfide is a colorless, poisonous and strongly acidic gases, once leaking caused by out of control for blowout, it will result in incalculable losses.%川东地区主要以产天然气为主,普遍存在的高压、高含硫、气层埋藏深的特点,石油钻井井控技术工作的难度之大,堪称中国陆上油气钻井施工风险之最.硫化氢是一种无色、剧毒、强酸性气体,一旦出现井喷失控硫化氢泄露,将造成不可估量的损失.

  6. Gap-bridging During Quasi-simultaneous Laser Transmission Welding

    Science.gov (United States)

    Schmailzl, Anton; Hierl, Stefan; Schmidt, Michael

    Tightness is often the main requirement for quasi-simultaneous laser transmission welds. However, remaining gaps cannot be detected by the used set-path monitoring. By using a pyrometer in combination with a 3D-scanner, weld seam interruptions can be localized precisely while welding, due to temperature deviations along the weld contour. To analyze the temperature signal in correlation to the progress of gap-bridging, T-joint samples with predefined gaps are welded. The set-path is measured synchronously. Additionally, the temperature distribution and the influence of the thermal expansion of the polymers are studied by a thermo-mechanical FEM-process simulation. On top of that, the melt blow-out of the welded samples is analyzed using μCT-measurements. The experiments have shown that closing of a gap can be identified reliably by the temperature signal and that the squeezed melt flow into the gap and the thermal expansion in the gap zone accelerates gap-bridging. Furthermore the inserted heat can be adapted in the fault zone, in order to avoid thermal damage.

  7. Firing blast furnace gas without support fuel in steel mill boilers

    Energy Technology Data Exchange (ETDEWEB)

    Hou, S.S.; Chen, C.H.; Chang, C.Y.; Wu, C.W.; Ou, J.J.; Lin, T.H. [National Cheng Kung University, Tainan (Taiwan). Dept. of Mechanical Engineering

    2011-07-15

    In this study, the combustion characteristics of firing blast furnace gas (BFG) individually or in combination with coke oven gas (COG) were investigated theoretically and experimentally. The theoretical results showed that at the same heat release rate under the operating conditions of stoichiometry, firing BFG individually had a greater amount of fuel gas volume flow rate, a smaller amount of air volume flow rate, and a lower adiabatic flame temperature than firing BFG with support fuel without preheating. Meanwhile, the volume flow rate of flue gas for the former was greater than the latter. The experimental results obtained from a co-firing of BFG and COG fueled-boiler in a steel company showed that whether at a higher or lower boiler load, with gradually decreasing the amount of COG supply, flame instability (lift-off and blow-out) did not occur and the rate of CO emission was very low. In addition, a decrease in the amount of COG supply brought about a great benefit to the reductions of both CO{sub 2} and NOx emissions.

  8. Cause and Counterplan for Sand Flow from Heavy Oil Thermal Recovery Wells in Bamianhe Oilfield%浅析八面河油田稠油热采井出砂原因及对策

    Institute of Scientific and Technical Information of China (English)

    焦小军; 曹平

    2012-01-01

    对八面河油田近年来的稠油热采井出砂情况统计分析认为,热采后出砂主要受防砂时间及方式、生产参数、热采轮次、出砂史的影响,放喷过程中压力下降快、下泵生产后动液面下降快等是其主要的表现特征。预防出砂,重点在于实施热采前的防砂处理和热采过程中的产生参数控制。%Statistic analysis of last few years of sand flow from thermal recovery wells in Bamianhe Oilfield concludes that sand flow is caused mainly by the time and method of sand prevention,production parameter,thermal recovery round as well as history of sand flow.Its main performance characteristics are the fast pressure drop in the process of blowout and fast drop of working fluid level when downhole pump starts production.To prevent sand flow,more attention should be paid to sand prevention handling ahead of thermal recovery and emerging parameter control during thermal recovery.

  9. A framework to quantify uncertainty in simulations of oil transport in the ocean

    KAUST Repository

    Gonçalves, Rafael C.

    2016-03-02

    An uncertainty quantification framework is developed for the DeepC Oil Model based on a nonintrusive polynomial chaos method. This allows the model\\'s output to be presented in a probabilistic framework so that the model\\'s predictions reflect the uncertainty in the model\\'s input data. The new capability is illustrated by simulating the far-field dispersal of oil in a Deepwater Horizon blowout scenario. The uncertain input consisted of ocean current and oil droplet size data and the main model output analyzed is the ensuing oil concentration in the Gulf of Mexico. A 1331 member ensemble was used to construct a surrogate for the model which was then mined for statistical information. The mean and standard deviations in the oil concentration were calculated for up to 30 days, and the total contribution of each input parameter to the model\\'s uncertainty was quantified at different depths. Also, probability density functions of oil concentration were constructed by sampling the surrogate and used to elaborate probabilistic hazard maps of oil impact. The performance of the surrogate was constantly monitored in order to demarcate the space-time zones where its estimates are reliable. © 2016. American Geophysical Union.

  10. The Development Strategy of Large Private Express Enterprise Electric Background%电商背景下大型民营快递企业发展策略

    Institute of Scientific and Technical Information of China (English)

    翁清清

    2014-01-01

    The rapid development of e -commerce has brought a make a spurt of progress , express logistics business volume of blowout type growth .However ,behind the prosperity of the development of express industry is extensive ,the enterprise uneven,some good and some bad problems .How to talent showing itself in the fierce competition in the market ,is an important task for large enterprises express .In -depth study aiming at the development status and characteristics of large courier companies ,analyzes the existing problems and put forward corresponding countermeasures .%电子商务的高速发展带来了快递物流的突飞猛进,业务量井喷式增长。然而快递业繁荣背后是粗放发展、企业良莠不齐的隐忧。如何在激烈的市场竞争中脱颖而出,是大型快递企业的重要课题。文中针对大型快递企业发展的现状与特点进行深入探讨,分析其存在的问题并提出相应的解决对策。

  11. Role of direct laser acceleration in energy gained by electrons in a laser wakefield accelerator with ionization injection

    CERN Document Server

    Shaw, J L; Vafaei-Najafabadi, N; Marsh, K A; Lemos, N; Mori, W B; Joshi, C

    2014-01-01

    We have investigated the role that the transverse electric field of the laser plays in the acceleration of electrons in a laser wakefield accelerator (LWFA) operating in the quasi-blowout regime through particle-in-cell code simulations. In order to ensure that longitudinal compression and/or transverse focusing of the laser pulse is not needed before the wake can self-trap the plasma electrons, we have employed the ionization injection technique. Furthermore, the plasma density is varied such that at the lowest densities, the laser pulse occupies only a fraction of the first wavelength of the wake oscillation (the accelerating bucket), whereas at the highest density, the same duration laser pulse fills the entire first bucket. Although the trapped electrons execute betatron oscillations due to the ion column in all cases, at the lowest plasma density they do not interact with the laser field and the energy gain is all due to the longitudinal wakefield. However, as the density is increased, there can be a sig...

  12. AMOP (Arctic Marine Oil Spill Program) studies reviewed

    Energy Technology Data Exchange (ETDEWEB)

    1978-06-05

    A discussion of the Arctic Marine Oil Spill Program organized in 1976 by the Canadian Federal Government includes: an Arctic Atlas compiled by Fenco Consultants Ltd. to give background information necessary for developing marine oil spill countermeasures for the Arctic north of 60/sup 0/ including the west Greenland coast and the Labrador shelf (geology, meteorology and oceanography, ice conditions, biology, and social factors); program in emergency transport of spill-combatting equipment; and the factors which influence the choice of conveyance, i.e., accessibility of the site, urgency for response, and quantity of material required; laboratory studies involving the release of oil under artificial sea ice in simulated ice formation and decay purposes to determine the interaction of crude oil and first-year sea ice; inability of companies and government to control a major spill in the Labrador Sea because of poor and inadequate transport facilities, communications, and navigational aids, severe environmental conditions, and logistics problems; and studies on the effects of oil-well blowouts in deep water, including formation of oil and gas hydrates, design of oil skimmers, the use of hovercraft, and specifications for an airborne multisensor system for oil detection in ice-infested waters.

  13. A dearth of small particles in debris disks: An energy-constrained smallest fragment size

    CERN Document Server

    Krijt, Sebastiaan

    2014-01-01

    A prescription for the fragment size distribution resulting from dust grain collisions is essential when modelling a range of astrophysical systems, such as debris disks and planetary rings. While the slope of the fragment size distribution and the size of the largest fragment are well known, the behaviour of the distribution at the small size end is theoretically and experimentally poorly understood. This leads debris disk codes to generally assume a limit equal to, or below, the radiation blow-out size. We use energy conservation to analytically derive a lower boundary of the fragment size distribution for a range of collider mass ratios. Focussing on collisions between equal-sized bodies, we apply the method to debris disks. For a given collider mass, the size of the smallest fragments is found to depend on collision velocity, material parameters, and the size of the largest fragment. We provide a physically motivated recipe for the calculation of the smallest fragment, which can be easily implemented in c...

  14. The Inner Disk Structure, Disk-Planet Interactions, and Temporal Evolution in the Beta Pictoris System: A Two-Epoch HST/STIS Coronagraphic Study

    CERN Document Server

    Apai, Daniel; Grady, Carol A; Wyatt, Mark C; Lagrange, Anne-Marie; Kuchner, Marc J; Stark, Christopher J; Lubow, Stephen H

    2015-01-01

    We present deep HST/STIS coronagraphic images of the Beta Pic debris disk obtained at two epochs separated by 15 years. The new images and the re-reduction of the 1997 data provide the most sensitive and detailed views of the disk at optical wavelengths as well as the yet smallest inner working angle optical coronagraphic image of the disk. Our observations characterize the large-scale and inner-disk asymmetries and we identify multiple breaks in the disk radial surface brightness profile. We study in detail the radial and vertical disk structure and show that the disk is warped. We explore the disk at the location of the Beta Pic b super-jupiter and find that the disk surface brightness slope is continuous between 0.5 and 2.0 arcsec, arguing for no change at the separations where Beta Pic b orbits. The two epoch images constrain the disk surface brightness evolution on orbital and radiation pressure blow-out timescales. We place an upper limit of 3% on the disk surface brightness change between 3-5 arcsec, i...

  15. Deep soil mixing for reagent delivery and contaminant treatment

    Energy Technology Data Exchange (ETDEWEB)

    Korte, N.; Gardner, F.G. [Oak Ridge National Lab., Grand Junction, CO (United States); Cline, S.R.; West, O.R. [Oak Ridge National Lab., TN (United States)] [and others

    1997-12-31

    Deep soil mixing was evaluated for treating clay soils contaminated with TCE and its byproducts at the Department of Energy`s Kansas City Plant. The objective of the project was to evaluate the extent of limitations posed by the stiff, silty-clay soil. Three treatment approaches were tested. The first was vapor stripping. In contrast to previous work, however, laboratory treatability studies indicated that mixing saturated, clay soil was not efficient unless powdered lime was added. Thus, powder injection of lime was attempted in conjunction with the mixing/stripping operation. In separate treatment cells, potassium permanganate solution was mixed with the soil as a means of destroying contaminants in situ. Finally, microbial treatment was studied in a third treatment zone. The clay soil caused operational problems such as breakage of the shroud seal and frequent reagent blowouts. Nevertheless, treatment efficiencies of more than 70% were achieved in the saturated zone with chemical oxidation. Although expensive ($1128/yd{sup 3}), there are few alternatives for soils of this type.

  16. Electric fields effect on liftoff and blowoff of nonpremixed laminar jet flames in a coflow

    KAUST Repository

    Kim, Minkuk

    2010-01-01

    The stabilization characteristics of liftoff and blowoff in nonpremixed laminar jet flames in a coflow have been investigated experimentally for propane fuel by applying AC and DC electric fields to the fuel nozzle with a single-electrode configuration. The liftoff and blowoff velocities have been measured by varying the applied voltage and frequency of AC and the voltage and the polarity of DC. The result showed that the AC electric fields extended the stabilization regime of nozzle-attached flame in terms of jet velocity. As the applied AC voltage increased, the nozzle-attached flame was maintained even over the blowout velocity without having electric fields. In such a case, a blowoff occurred directly without experiencing a lifted flame. While for the DC cases, the influence on liftoff was minimal. There existed three different regimes depending on the applied AC voltage. In the low voltage regime, the nozzle-detachment velocity of either liftoff or blowoff increased linearly with the applied voltage, while nonlinearly with the AC frequency. In the intermediate voltage regime, the detachment velocity decreased with the applied voltage and reasonably independent of the AC frequency. At the high voltage regime, the detachment was significantly influenced by the generation of discharges. © 2009 The Combustion Institute.

  17. Cusp-shaped Structure of a Jet Observed By IRIS and SDO

    Science.gov (United States)

    Zhang, Yuzong; Zhang, Jun

    2017-01-01

    On 2014 August 29, the trigger and evolution of a cusp-shaped jet were captured in detail at 1330 Å by the Interface Region Imaging Spectrograph. At first, two neighboring mini-prominences arose in turn from the low solar atmosphere and collided with a loop-like system over them. The collisions between the loop-like system and the mini-prominences lead to the blowout, and then a cusp-shaped jet formed with a spire and an arch-base. In the spire, many brightening blobs originating from the junction between the spire and the arch-base moved upward in a rotating manner and then in a straight line in the late phase of the jet. In the arch-base, dark and bright material simultaneously tracked in a fan-like structure, and the majority of the material moved along the fan's threads. At the later phase of the jet's evolution, bidirectional flows emptied the arch-base, while downflows emptied the spire, thus making the jet entirely vanish. The extremely detailed observations in this study shed new light on how magnetic reconnection alters the inner topological structure of a jet and provides a beneficial complement for understanding current jet models.

  18. The dust grain size - stellar luminosity trend in debris discs

    CERN Document Server

    Pawellek, Nicole

    2015-01-01

    The cross section of material in debris discs is thought to be dominated by the smallest grains that can still stay in bound orbits despite the repelling action of stellar radiation pressure. Thus the minimum (and typical) grain size $s_\\text{min}$ is expected to be close to the radiation pressure blowout size $s_\\text{blow}$. Yet a recent analysis of a sample of Herschel-resolved debris discs showed the ratio $s_\\text{min}/s_\\text{blow}$ to systematically decrease with the stellar luminosity from about ten for solar-type stars to nearly unity in the discs around the most luminous A-type stars. Here we explore this trend in more detail, checking how significant it is and seeking to find possible explanations. We show that the trend is robust to variation of the composition and porosity of dust particles. For any assumed grain properties and stellar parameters, we suggest a recipe of how to estimate the "true" radius of a spatially unresolved debris disc, based solely on its spectral energy distribution. The r...

  19. Operational verification of a blow out preventer utilizing fiber Bragg grating based strain gauges

    Science.gov (United States)

    Turner, Alan L.; Loustau, Philippe; Thibodeau, Dan

    2015-05-01

    Ultra-deep water BOP (Blowout Preventer) operation poses numerous challenges in obtaining accurate knowledge of current system integrity and component condition- a salient example is the difficulty of verifying closure of the pipe and shearing rams during and after well control events. Ascertaining the integrity of these functions is currently based on a manual volume measurement performed with a stop watch. Advances in sensor technology now permit more accurate methods of BOP condition monitoring. Fiber optic sensing technology and particularly fiber optic strain gauges have evolved to a point where we can derive a good representation of what is happening inside a BOP by installing sensors on the outside shell. Function signatures can be baselined to establish thresholds that indicate successful function activation. Based on this knowledge base, signal variation over time can then be utilized to assess degradation of these functions and subsequent failure to function. Monitoring the BOP from the outside has the advantage of gathering data through a system that can be interfaced with risk based integrity management software and/or a smart monitoring system that analyzes BOP control redundancies without the requirement of interfacing with OEM control systems. The paper will present the results of ongoing work on a fully instrumented 13-½" 10,000 psi pipe ram. Instrumentation includes commonly used pressure transducers, accelerometers, flow meters, and optical strain gauges. Correlation will be presented between flow, pressure, acceleration signatures and the fiber optic strain gauge's response as it relates to functional verification and component level degradation trending.

  20. Detonation equation of state at LLNL, 1995. Revision 3

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-02-01

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

  1. Effects of Pollution on Marine Organisms.

    Science.gov (United States)

    Mearns, Alan J; Reish, Donald J; Oshida, Philip S; Morrison, Ann Michelle; Rempel-Hester, Mary Ann; Arthur, Courtney; Rutherford, Nicolle; Pryor, Rachel

    2016-10-01

    This review covers selected 2015 articles on the biological effects of pollutants and human physical disturbances on marine and estuarine plants, animals, ecosystems and habitats. The review, based largely on journal articles, covers field and laboratory measurement activities (bioaccumulation of contaminants, field assessment surveys, toxicity testing and biomarkers) as well as pollution issues of current interest including endocrine disrupters, emerging contaminants, wastewater discharges, dredging and disposal, etc. Special emphasis is placed on effects of oil spills and marine debris due largely to the 2010 Deepwater Horizon oil blowout in the Gulf of Mexico. Several topical areas reviewed in the past (ballast water and ocean acidification) were dropped this year. The focus of this review is on effects, not pollutant fate and transport. There is considerable overlap across subject areas (e.g.some bioaccumulation papers may be cited in other topical categories). Please use keyword searching of the text to locate related but distributed papers. Use this review only as a guide and please consult the original papers before citing them.

  2. Herschel Observations and Updated Spectral Energy Distributions of Five Sunlike Stars with Debris Disks

    Science.gov (United States)

    Dodson-Robinson, Sarah E.; Su, Kate Y. L.; Bryden, Geoff; Harvey, Paul; Green, Joel D.

    2016-12-01

    Observations from the Herschel Space Observatory have more than doubled the number of wide debris disks orbiting Sunlike stars to include over 30 systems with R > 100 AU. Here, we present new Herschel PACS and reanalyzed Spitzer MIPS photometry of five Sunlike stars with wide debris disks, from Kuiper Belt size to R > 150 AU. The disk surrounding HD 105211 is well resolved, with an angular extent of >14″ along the major axis, and the disks of HD 33636, HD 50554, and HD 52265 are extended beyond the PACS point-spread function size (50% of energy enclosed within radius 4.″23). HD 105211 also has a 24 μm infrared excess, which was previously overlooked, because of a poorly constrained photospheric model. Archival Spitzer IRS observations indicate that the disks have small grains of minimum radius a min ˜ 3 μm, although a min is larger than the radiation-pressure blowout size in all systems. If modeled as single-temperature blackbodies, the disk temperatures would all be <60 K. Our radiative transfer models predict actual disk radii approximately twice the radius of a model blackbody disk. We find that the Herschel photometry traces dust near the source population of planetesimals. The disk luminosities are in the range 2 × 10-5 ⩽ L/L ⊙ ⩽ 2 × 10-4, consistent with collisions in icy planetesimal belts stirred by Pluto-size dwarf planets.

  3. X-ray emission from the Wolf-Rayet bubble NGC 6888. II. XMM-Newton EPIC observations

    CERN Document Server

    Toalá, J A; Chu, Y -H; Arthur, S J; Tafoya, D; Gruendl, R A

    2015-01-01

    We present deep XMM-Newton EPIC observations of the Wolf-Rayet (WR) bubble NGC6888 around the star WR136. The complete X-ray mapping of the nebula confirms the distribution of the hot gas in three maxima spatially associated with the caps and northwest blowout hinted at by previous Chandra observations. The global X-ray emission is well described by a two-temperature optically thin plasma model $T_1$=1.4$\\times$10$^{6}$ K, $T_{2}$=8.2$\\times$10$^{6}$ K) with a luminosity of $L_{\\mathrm{X}}$=7.8$\\times$10$^{33}$ erg s$^{-1}$ in the 0.3--1.5 keV energy range. The rms electron density of the X-ray-emitting gas is estimated to be $n_\\mathrm{e}$=0.4 cm$^{-3}$. The high-quality observations presented here reveal spectral variations within different regions in NGC6888, which allowed us for the first time to detect temperature and/or nitrogen abundance inhomogeneities in the hot gas inside a WR nebula. One possible explanation for such spectral variations is that the mixing of material from the outer nebula into the ...

  4. Plasmon-enhanced photocathode for high brightness and high repetition rate x-ray sources

    Energy Technology Data Exchange (ETDEWEB)

    Polyakov, Aleksandr; Senft, Christoph; Thompson, K. F.; Feng, J.; Cabrini, S.; Schuck, P. J.; Padmore, Howard; Peppernick, Samuel J.; Hess, Wayne P.

    2013-02-11

    High brightness electron sources are at the heart of anew generation of x-ray sources based on the Free ElectronLaser (FEL) as well as in Energy Recovery Linac (ERL) and Inverse Compton Scattering (ICS) sources.The source of electrons consists of a photoinjector, comprised of a laser-driven photocathode in a high gradient electric field produced by an rf cavity. The function of the rf cavity is to provide a field sufficient for acceleration of electrons to relativistic velocity over a small distance, thus minimizing effects of the space-charge. Even so, the dense electron beam required for high brightness suffers from a space charge field that chirps and reshapes the electron pulse increasing beam emittance and thus reducing the overall brightness. This emittance growth can be avoided if the initial distribution of electrons is pancake shaped, with a semicircular transverse intensity profile. In this case, the electron distribution develops under its space charge field from a pancake into a uniformly filled ellipsoidal beam. This condition, referred to as the blowout regime, requires ultrashort pulses less than 100 fs long and has been successfully demonstrated recently in a high gradient photoinjector.

  5. Study of methane solubility in oil base used in oil base drilling fluid; Estudo da solubilidade de metano em base oleo utilizada em fluido de perfuracao base oleo

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Carolina Teixeira da; Mariolani, Jose Ricardo Lenzi [Universidade Estadual de Campinas, SP (Brazil); Ribeiro, Paulo Roberto; Lomba, Rosana Fatima Teixeira; Bonet, Euclides Jose

    2004-07-01

    During drilling a well, it is necessary to prevent and control high pressurized zones because while drilling on those zones, could occur a kick if the formation pressure were higher then downhole pressure, allowing the entering of undesirables fluids from the formation to the wellbore. If the well is not controlled this kick could became a blowout, generating damages to the environment, to the equipment and the human life. When drilling using oil-based mud, the concern related to the well control would be higher due the gas solubility in the mud, which could make it hard to detect the kick, especially in deep and ultra deep waters. In this work we have studied the interaction between methane and organic liquids used in drilling fluids, and the measurement and analysis of the thermodynamic properties of those gas liquid mixtures. There have been measured parameters like the oil formation volume factor (FVF{sub o}), bubble pressure, solubility (Rs) and the density of the saturated liquid in function of methane mole fraction and temperature. The results have shown that the gas solubility, at downhole conditions and during kick circulation, is a factor very important to the safety during well drilling in deep and ultra deep waters. (author)

  6. Methane emissions from oceans, coasts, and freshwater habitats: New perspectives and feedbacks on climate

    Science.gov (United States)

    Hamdan, Leila J.; Wickland, Kimberly P.

    2016-01-01

    Methane is a powerful greenhouse gas, and atmospheric concentrations have risen 2.5 times since the beginning of the Industrial age. While much of this increase is attributed to anthropogenic sources, natural sources, which contribute between 35% and 50% of global methane emissions, are thought to have a role in the atmospheric methane increase, in part due to human influences. Methane emissions from many natural sources are sensitive to climate, and positive feedbacks from climate change and cultural eutrophication may promote increased emissions to the atmosphere. These natural sources include aquatic environments such as wetlands, freshwater lakes, streams and rivers, and estuarine, coastal, and marine systems. Furthermore, there are significant marine sediment stores of methane in the form of clathrates that are vulnerable to mobilization and release to the atmosphere from climate feedbacks, and subsurface thermogenic gas which in exceptional cases may be released following accidents and disasters (North Sea blowout and Deepwater Horizon Spill respectively). Understanding of natural sources, key processes, and controls on emission is continually evolving as new measurement and modeling capabilities develop, and different sources and processes are revealed. This special issue of Limnology and Oceanography gathers together diverse studies on methane production, consumption, and emissions from freshwater, estuarine, and marine systems, and provides a broad view of the current science on methane dynamics of aquatic ecosystems. Here, we provide a general overview of aquatic methane sources, their contribution to the global methane budget, and key uncertainties. We then briefly summarize the contributions to and highlights of this special issue.

  7. Cusp-shaped structure of a jet observed by IRIS and SDO

    CERN Document Server

    Yuzong, Zhang

    2016-01-01

    On 29 August 2014, the trigger and evolution of a cusp-shaped jet were captured in detail at 1330 {\\AA} by the Interface Region Imaging Spectrograph.At first, two neighboring mini-prominences arose in turn from low solar atmosphere and collided with a loop-like system over them. The collisions between the loop-like system and the mini-prominences lead to the blowout and then a cusp-shaped jet formed with a spire and an arch-base. In the spire, many brightening blobs originating from the junction between the spire and the arch-base, moved upward in a rotating manner and then in a straight line in the late phase of the jet. In the arch-base, dark and bright material simultaneously tracked in a fan-like structure and the majority of the material moved along the fan's threads. At the later phase of the jet's evolution, bidirectional flows emptied the arch-base, while down-flows emptied the spire, thus making the jet entirely vanish. The extremely detailed observations in this study shed new light on how magnetic ...

  8. Effect of dilution holes on the performance of a triple swirler combustor

    Directory of Open Access Journals (Sweden)

    Ding Guoyu

    2014-12-01

    Full Text Available A triple swirler combustor is considered to be a promising solution for future high temperature rise combustors. The present paper aims to study dilution holes including primary dilution holes and secondary dilution holes on the performance of a triple swirler combustor. Experimental investigations are conducted at different inlet airflow velocities (40–70 m/s and combustor overall fuel–air ratio with fixed inlet airflow temperature (473 K and atmospheric pressure. The experimental results show that the ignition is very difficult with specific performance of high ignition fuel–air ratio when the primary dilution holes are located 0.6H (where H is the liner dome heightdownstream the dome, while the other four cases have almost the same ignition performance. The position of primary dilution holes has an effect on lean blowout stability and has a large influence on combustion efficiency. The combustion efficiency is the highest when the primary dilution holes are placed 0.9H downstream the dome among the five different locations. For the secondary dilution holes, the pattern factor of Design A is better than that of Design B.

  9. Effect of dilution holes on the performance of a triple swirler combustor

    Institute of Scientific and Technical Information of China (English)

    Ding Guoyu; He Xiaomin; Zhao Ziqiang; An Bokun; Song Yaoyu; Zhu Yixiao

    2014-01-01

    A triple swirler combustor is considered to be a promising solution for future high temperature rise combustors. The present paper aims to study dilution holes including primary dilu-tion holes and secondary dilution holes on the performance of a triple swirler combustor. Experi-mental investigations are conducted at different inlet airflow velocities (40–70 m/s) and combustor overall fuel–air ratio with fixed inlet airflow temperature (473 K) and atmospheric pressure. The experimental results show that the ignition is very difficult with specific performance of high ignition fuel–air ratio when the primary dilution holes are located 0.6H (where H is the liner dome height)downstream the dome, while the other four cases have almost the same ignition performance. The position of primary dilution holes has an effect on lean blowout stability and has a large influence on combustion efficiency. The combustion efficiency is the highest when the primary dilution holes are placed 0.9H downstream the dome among the five different locations. For the secondary dilution holes, the pattern factor of Design A is better than that of Design B.

  10. A Coronal Hole Jet Observed with Hinode and the Solar Dynamics Observatory

    CERN Document Server

    Young, Peter R

    2014-01-01

    A small blowout jet was observed at the boundary of the south coronal hole on 2011 February 8 at around 21:00 UT. Images from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO) revealed an expanding loop rising from one footpoint of a compact, bipolar bright point. Magnetograms from the Helioseismic Magnetic Imager (HMI) on board SDO showed that the jet was triggered by the cancelation of a parasitic positive polarity feature near the negative pole of the bright point. The jet emission was present for 25 mins and it extended 30 Mm from the bright point. Spectra from the EUV Imaging Spectrometer on board Hinode yielded a temperature and density of 1.6 MK and 0.9-1.7 x 10^8 cm^-3 for the ejected plasma. Line-of-sight velocities reached up to 250 km/s. The density of the bright point was 7.6 x 10^8 cm^-3, and the peak of the bright point's emission measure occurred at 1.3 MK, with no plasma above 3 MK.

  11. Leakage Risk Assessment of CO{sub 2} Transportation by Pipeline at the Illinois Basin Decatur Project, Decatur, Illinois

    Energy Technology Data Exchange (ETDEWEB)

    Mazzoldi, A.; Oldenburg, C. M.

    2013-12-17

    the pipeline route within the ADM plant. Leakage scenarios at sites along the route of the pipeline, where plant operations (e.g., vehicular and train transportation) seem to present a higher likelihood of accidental failure, for example due to vehicles or equipment crashing into the pipeline and completely severing it, were modeled by allowing them to have a double source consistent with the pipeline releasing high-pressure CO{sub 2} from both ends of the broken pipe after a full-bore offset rupture. Simulation results show that the built environment of the plant plays a significant role in the dispersion of the gas as leaking CO{sub 2} can impinge upon buildings and other infrastructure. In all scenarios simulated, the region of very high-concentration of CO{sub 2} is limited to a small area around the pipeline failure, suggesting the likelihood of widespread harmful CO{sub 2} exposure to plant personnel from pipeline leakage is low. An additional risk is posed by the blast wave that emanates from a high-pressure pipeline when it is breached quickly. We estimate the blast wave risk as low because it occurs only for a short time in the immediate vicinity of the rupture, and requires an instantaneous large-scale rupture to occur. We recommend consideration of signage and guard rails and posts to mitigate the likelihood of vehicles crashing into the pipeline. A standardized emergency response plan applicable to capture plants within industrial sites could be developed based on the IBDP that would be useful for other capture plants. Finally, we recommend carrying out coupled wellbore-reservoir blowout scenario modeling to understand the potential for hazardous conditions arising from an unexpected blowout at the wellhead.

  12. Understanding the build-up of supermassive black holes and galaxies

    Science.gov (United States)

    Carrera, Francisco; Ueda, Yoshihiro; Georgakakis, Antonis

    2016-07-01

    One of the main open questions in modern Astrophysics is understanding the coupled growth of supermassive black holes by accretion and their host galaxies via star formation, from their peak at redshifts z~ 1-4 to the present time. The generic scenario proposed involves an early phase of intense black hole growth that takes place behind large obscuring columns of inflowing dust and gas clouds. It is postulated that this is followed by a blow-out stage during which some form of AGN feedback controls the fate of the interstellar medium and hence, the evolution of the galaxy. X-rays are essential for testing this scenario as they uniquely probe AGN at both the early heavily obscured stage and the later blow-out phase. X-ray spectral analysis can identify the smoking gun evidence of heavily obscured black hole growth (e.g. intense iron Kalpha line). It therefore provides the most robust method for compiling clean samples of deeply shrouded AGN with well-defined selection functions and unbiased determinations of their intrinsic properties (accretion luminosity, obscuring column). X-rays are also the best window for studying in detail AGN feedback. This process ultimately originates in the innermost regions close to the supermassive black hole and is dominated, in terms of energy and mass flux, by highly ionisedmaterial that remains invisible at other wavelengths. The most important epoch for investigating the relation between AGN and galaxies is the redshift range z~1-4, when most black holes and stars we see in the present-day Universe were put in place. Unfortunately, exhaustive efforts with current high-energy telescopes only scrape the tip of the iceberg of the most obscured AGN population. Moreover, Xray studies of the incidence, nature and energetics of AGN feedback are limited to the local Universe. The Athena observatory will provide the technological leap required for a breakthrough in our understanding of AGN and galaxy evolution at the heyday of the Universe

  13. Quantitative Risk Assessment for Natural Gas Well with Hydrogen Sulfide%含硫气井定量风险分析方法

    Institute of Scientific and Technical Information of China (English)

    吴庆善; 钱新明; 郭再富; 黄平

    2009-01-01

    随中国经济对石油天然气能源依赖程度的加深,大力开发含硫化氢气田成为重要任务,而定量评价含硫气井的风险显得更加必要和迫切.提出了含硫气井井喷事故硫化氢泄漏扩散过程中个人风险定量计算方法,根据相关统计资料,提出了井喷事故概率的参考值,将该方法应用于川渝地区某含硫气井,获取了该井周边区域个人风险等值线,并与可接受风险水平进行对比分析.结果表明,由于地形条件的影响,在气井周边不同方向的个人风险水平差异很大,可接受风险水平上限值等值线距井口的距离在不同方位上相差可达1000 m,在对气井进行定量风险分析时必须充分加以考虑.该方法可为油气田开发企业、安全监管部门对含硫气井开发过程实施定量风险评价和管理提供有效技术手段,并为应急计划区的划分及边界确定提供参考.%With the heavy dependence of domestic economy on oil and gas,the exploitation of natural gas fields with hydrogen sulfide is an urgent project in China.The quantitative risk assessment for natural gas wells with hydrogen sulfide is a necessary and impending requirement.A quantitative calculation method for an individual risk for leakage and dispersion process of hydrogen sulfide in blowout of gas wells is proposed in this paper.Based on the statistical analysis of data in literature,the probability of blowout incident is brought forward for reference.The method is applied to a typical gas well in Sichuan and Chongqing district as a practical example.The contour curves of individual risks in the area around the well are obtained,and compared with the acceptable level of the individual risks.The results show that the topographic conditions of the gas well greatly influence the calculation results of the individual risks,the distance between the upper limit isoline of acceptable risk and the well in different directions can reach 1000 m.So it must

  14. Monitoring instream turbidity to estimate continuous suspended-sediment loads and yields and clay-water volumes in the upper North Santiam River Basin, Oregon, 1998-2000

    Science.gov (United States)

    Uhrich, Mark A.; Bragg, Heather M.

    2003-01-01

    Three real-time, instream water-quality and turbidity-monitoring sites were established in October 1998 in the upper North Santiam River Basin on the North Santiam River, the Breitenbush River, and Blowout Creek, the main tributary inputs to Detroit Lake, a large, controlled reservoir that extends from river mile 61 to 70. Suspended-sediment samples were collected biweekly to monthly at each station. Rating curves provided estimated suspended-sediment concentration in 30-minute increments from log transformations of the instream turbidity monitoring data. Turbidity was found to be a better surrogate than discharge for estimating suspended-sediment concentration. Daily and annual mean suspended-sediment loads were estimated using the estimated suspended-sediment concentrations and corresponding streamflow data. A laboratory method for estimating persistent (residual) turbidity from separate turbidity samples was developed. Turbidity was measured over time for each sample. Turbidity decay curves were derived as the suspended sediment settled. Each curve was used to estimate a turbidity value for a given settling time. Medium to fine clay particle (size clay particle persistent turbidity for each site. The monitored instream 30-minute turbidity values were converted to a calculated persistent turbidity value that would have resulted after 8.5 hours of settling in the laboratory. Persistent turbidities of 10 NTU and above were tabulated for each site. (Water of 10 NTU and above can interfere with or damage treatment filters and result in intake closures at drinking-water facilities.) A method was developed that used the persistent turbidity experiments, turbidity decay curves, and stream discharge to estimate the volume of water containing suspended clay that entered Detroit Lake from the three main tributaries. 'Suspended-clay water' was defined as water having a value of at least 10 NTU after settling the required 8.5 hours. The suspended-clay concentrations of 10

  15. Well Integrity for Natural Gas Storage in Depleted Reservoirs and Aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Freifeld, Barry M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Oldenburg, Curtis M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Jordan, Preston [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Pan, Lehua [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Perfect, Scott [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Morris, Joseph [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); White, Joshua [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bauer, Stephen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Blankenship, Douglas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Roberts, Barry [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bromhal, Grant [National Energy Technology Lab. (NETL), Morgantown, WV (United States); Glosser, Deborah [National Energy Technology Lab. (NETL), Morgantown, WV (United States); Wyatt, Douglas [National Energy Technology Lab. (NETL), Morgantown, WV (United States); Rose, Kelly [National Energy Technology Lab. (NETL), Morgantown, WV (United States)

    2016-09-02

    Introduction Motivation The 2015-2016 Aliso Canyon/Porter Ranch natural gas well blowout emitted approximately 100,000 tonnes of natural gas (mostly methane, CH4) over four months. The blowout impacted thousands of nearby residents, who were displaced from their homes. The high visibility of the event has led to increased scrutiny of the safety of natural gas storage at the Aliso Canyon facility, as well as broader concern for natural gas storage integrity throughout the country. Federal Review of Well Integrity In April of 2016, the U.S. Department of Energy (DOE), in conjunction with the U.S. Department of Transportation (DOT) through the Pipeline and Hazardous Materials Safety Administration (PHMSA), announced the formation of a new Interagency Task Force on Natural Gas Storage Safety. The Task Force enlisted a group of scientists and engineers at the DOE National Laboratories to review the state of well integrity in natural gas storage in the U.S. The overarching objective of the review is to gather, analyze, catalogue, and disseminate information and findings that can lead to improved natural gas storage safety and security and thus reduce the risk of future events. The “Protecting our Infrastructure of Pipelines and Enhancing Safety Act of 2016’’ or the ‘‘PIPES Act of 2016,’’which was signed into law on June 22, 2016, created an Aliso Canyon Natural Gas Leak Task Force led by the Secretary of Energy and consisting of representatives from the DOT, Environmental Protection Agency (EPA), Department of Health and Human Services, Federal Energy Regulatory Commission (FERC), Department of Commerce and the Department of Interior. The Task Force was asked to perform an analysis of the Aliso Canyon event and make recommendations on preventing similar incidents in the future. The PIPES Act also required that DOT/PHMSA promulgate minimum safety standards for underground storage that would take effect within two years. Background on the DOE

  16. Hygienic support of the ISS air quality (main achievements and prospects)

    Science.gov (United States)

    Moukhamedieva, Lana; Tsarkov, Dmitriy; Pakhomova, Anna

    Hygienic preventive measures during pre-flight processing of manned spaceships, selection of polymeric materials, sanitary-hygienic evaluation of cargo and scientific hardware to be used on the ISS and life support systems allow to maintain air quality in limits of regulatory requirements. However, graduate increase of total air contamination by harmful chemicals is observed as service life of the ISS gets longer. It is caused by polymeric materials used on the station overall quantity rise, by additional contamination brought by cargo spacecrafts and modules docking to the ISS and by the cargo. At the same time the range of contaminants that are typical for off-gassing from polymeric materials where modern stabilizers, plasticizers, flame retarders and other additives are used gets wider. In resolving the matters of the ISS service life extension the main question of hygienic researches is to determine real safe operation life of the polymeric material used in structures and hardware of the station, including: begin{itemize} research of polymers degradation (ageing) and its effect on intensity of off gassing and its toxicity; begin{itemize} introduction of polymers with minimal volatile organic compounds off gassing under conditions of space flight and thermal-oxidative degradation. In order to ensure human safety during long-term flight it is important to develop: begin{itemize} real-time air quality monitoring systems, including on-line analysis of highly toxic contaminants evolving during thermo-oxidative degradation of polymer materials and during blowouts of toxic contaminants; begin{itemize} hygienic standards of contaminants level for extended duration of flight up to 3 years. It is essential to develop an automated control system for on-line monitoring of toxicological status and to develop hygienic and engineer measures of its management in order to ensure crew members safety during off-nominal situation.

  17. 眶壁骨折合并眶内皮样囊肿一例%Orbital fracture combine with orbital dermoid cyst:a case report

    Institute of Scientific and Technical Information of China (English)

    陈洋; 张玉萍; 谭婧瑾

    2016-01-01

    With the increase of ocular trauma patients,the occurrence rate of orbital blowout fracture (orbital wall fracture for short)is also gradually increasing.Orbital wall fracture has become one of the com-mon diseases in the department of ophthalmology.Orbital endothelial cyst is also relatively common,which often is found in the early childhood and progresses slowly.One case of juvenile patients of 12 years old was reported in this paper,positive preoperative examination revealed orbital wall fracture combined orbital endothelial cyst. Orbital wall fracture repairing,bone defect repairing and orbital placeholder resection were carried out.Diagno-sis and treatment of the case suggested detailed examination and judgment should be performed in the process of diagnosis and determine the surgical treatment,so as to avoid missed diagnosis.%随着眼外伤患者的增多,眶壁爆裂性骨折(简称眶壁骨折)的发生率也呈逐渐上升趋势,眶壁骨折已成为眼科常见的疾病之一。眶内皮样囊肿也较常见,多在幼儿时期被发现,但进展缓慢。该文报告1例12岁少年患者,术前积极检查发现其眶壁骨折合并眶内皮样囊肿,行眶壁骨折修复,眶骨缺损修补术,眶内占位切除术。该例患者诊治经过提示,在诊断和确定手术治疗方案的过程中应进行详细的检查与判断,避免出现漏诊。

  18. Flame kernel generation and propagation in turbulent partially premixed hydrocarbon jet

    KAUST Repository

    Mansour, Mohy S.

    2014-04-23

    Flame development, propagation, stability, combustion efficiency, pollution formation, and overall system efficiency are affected by the early stage of flame generation defined as flame kernel. Studying the effects of turbulence and chemistry on the flame kernel propagation is the main aim of this work for natural gas (NG) and liquid petroleum gas (LPG). In addition the minimum ignition laser energy (MILE) has been investigated for both fuels. Moreover, the flame stability maps for both fuels are also investigated and analyzed. The flame kernels are generated using Nd:YAG pulsed laser and propagated in a partially premixed turbulent jet. The flow field is measured using 2-D PIV technique. Five cases have been selected for each fuel covering different values of Reynolds number within a range of 6100-14400, at a mean equivalence ratio of 2 and a certain level of partial premixing. The MILE increases by increasing the equivalence ratio. Near stoichiometric the energy density is independent on the jet velocity while in rich conditions it increases by increasing the jet velocity. The stability curves show four distinct regions as lifted, attached, blowout, and a fourth region either an attached flame if ignition occurs near the nozzle or lifted if ignition occurs downstream. LPG flames are more stable than NG flames. This is consistent with the higher values of the laminar flame speed of LPG. The flame kernel propagation speed is affected by both turbulence and chemistry. However, at low turbulence level chemistry effects are more pronounced while at high turbulence level the turbulence becomes dominant. LPG flame kernels propagate faster than those for NG flame. In addition, flame kernel extinguished faster in LPG fuel as compared to NG fuel. The propagation speed is likely to be consistent with the local mean equivalence ratio and its corresponding laminar flame speed. Copyright © Taylor & Francis Group, LLC.

  19. Autoignited and non-autoignited lifted flames of pre-vaporized n-heptane in coflow jets at elevated temperatures

    KAUST Repository

    Choi, Sangkyu

    2013-09-01

    The characteristics of laminar lifted flames of pre-vaporized n-heptane in coflow jets were investigated under both non-autoignited and autoignited conditions by varying the initial temperature. The fuel tested was n-heptane considering the importance as a primary reference fuel for gasoline and its low temperature ignition behavior at relatively low pressure. The results showed that the lifted flame edge in the non-autoignited regime had a tribrachial structure with lean and rich premixed flame wings together with a trailing diffusion flame. The liftoff heights correlated reasonably well with the fuel jet velocity scaled by the stoichiometric laminar burning velocity regardless of the initial temperature and the nitrogen dilution. The liftoff velocity multiplied by the buoyancy-induced velocity and the blowout velocity scaled by the mole fraction of the fuel correlated well with the stoichiometric laminar burning velocity. When the initial temperature was above 900. K, flames were autoignited without any external ignition source. Autoignited lifted flames with both tribrachial edges and mild combustion characteristics were observed. The correlation of the liftoff height with the calculated adiabatic ignition delay time was weak, unlike in cases with gaseous fuels of C1-C4 hydrocarbons in which the liftoff height of the autoignited flames correlated well with the square of the adiabatic ignition delay time. When the mole fraction of the fuel was small, mild combustion behaviors were exhibited with edge flames without distinct tribrachial structures. The liftoff height was correlated with the fuel jet velocity scaled by the initial fuel mass fraction, while the dependence on the ignition delay time was weak when compared with the gaseous fuels. © 2013 The Combustion Institute.

  20. Microbial activities and dissolved organic matter dynamics in oil-contaminated surface seawater from the Deepwater Horizon oil spill site.

    Directory of Open Access Journals (Sweden)

    Kai Ziervogel

    Full Text Available The Deepwater Horizon oil spill triggered a complex cascade of microbial responses that reshaped the dynamics of heterotrophic carbon degradation and the turnover of dissolved organic carbon (DOC in oil contaminated waters. Our results from 21-day laboratory incubations in rotating glass bottles (roller bottles demonstrate that microbial dynamics and carbon flux in oil-contaminated surface water sampled near the spill site two weeks after the onset of the blowout were greatly affected by activities of microbes associated with macroscopic oil aggregates. Roller bottles with oil-amended water showed rapid formation of oil aggregates that were similar in size and appearance compared to oil aggregates observed in surface waters near the spill site. Oil aggregates that formed in roller bottles were densely colonized by heterotrophic bacteria, exhibiting high rates of enzymatic activity (lipase hydrolysis indicative of oil degradation. Ambient waters surrounding aggregates also showed enhanced microbial activities not directly associated with primary oil-degradation (β-glucosidase; peptidase, as well as a twofold increase in DOC. Concurrent changes in fluorescence properties of colored dissolved organic matter (CDOM suggest an increase in oil-derived, aromatic hydrocarbons in the DOC pool. Thus our data indicate that oil aggregates mediate, by two distinct mechanisms, the transfer of hydrocarbons to the deep sea: a microbially-derived flux of oil-derived DOC from sinking oil aggregates into the ambient water column, and rapid sedimentation of the oil aggregates themselves, serving as vehicles for oily particulate matter as well as oil aggregate-associated microbial communities.

  1. Ranchero Armature Test LA-19.4-CT-3: PBX-9501 Explosive with no smoothing layer. Firing point 88, 9/16/13

    Energy Technology Data Exchange (ETDEWEB)

    Glover, Brian B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Goforth, James H. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rae, Philip John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dickson, Peter [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Briggs, Matthew E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Marr-Lyon, Mark [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hare, Steven John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Herrera, Dennis Harold [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Watt, Robert Gregory [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rousculp, Christopher L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-11-13

    LA-19.4-CT-3 (CT-3) was the third camera test in a series beginning in 1/11, which diagnose the performance of 6 mm thick, 6061 T-0 Al Ranchero armatures. [The test LA-43-CT-2 (CT-2) is described in LA-UR-14-21983.] The goal of CT-3 was to verify that PBX-9501, with 18 mm point spacing and no smoothing layer, could be used for Ranchero generator armatures in place of PBXN-110, which had been used in all previous Ranchero applications. CT-1 and CT-2 both had 43 cm long slapper detonator systems imbedded in the cast PBXN-110 explosive, but manufacturing a charge for a similar 9501 test was not cost effective. Instead, a single cylinder of 9501, 19.368 cm long and 15.494 cm (6.100”)in diameter, had a groove machined to accommodate a row of 11 SE-1 detonators with 18 mm point spacing along the mid-plane of the cylinder. The expansion of the armature looks like a slapper assembly along almost ½ of the circumference, and provides adequate proof of concept. Removing the smoother from PBXN-110-driven armatures increased the armature velocity from 3.1 mm/μs to 3.3 mm/μs, as seen in CT-2, and the velocity measured on CT-3 increased to 3.8 mm/μs. In addition, the camera records show that the surface of the armature is smooth enough, and free from ruptures for an expansion of greater that 2X. The advantage of using 9501 is that it precludes concerns about blow-outs seen when bubbles are left in the cast material, and gives extra velocity. The disadvantage is that the machined explosives are more expensive.

  2. The polycyclic aromatic hydrocarbon degradation potential of Gulf of Mexico coastal microbial communities after the Deepwater Horizon oil spill

    Directory of Open Access Journals (Sweden)

    Anthony D. Kappell

    2014-05-01

    Full Text Available The Deepwater Horizon (DWH blowout resulted in oil transport, including polycyclic aromatic hydrocarbons (PAHs to the Gulf of Mexico shoreline. The microbial communities of these shorelines are thought to be responsible for the intrinsic degradation of PAHs. To investigate the Gulf Coast beach microbial community response to hydrocarbon exposure, we examined the functional gene diversity, bacterial community composition, and PAH degradation capacity of a heavily oiled and non-oiled beach following the oil exposure. With a non-expression functional gene microarray targeting 539 gene families, we detected 28,748 coding sequences. Of these sequences, 10% were uniquely associated with the severely oil-contaminated beach and 6.0% with the non-oiled beach. There was little variation in the functional genes detected between the two beaches; however the relative abundance of functional genes involved in oil degradation pathways, including PAHs, were greater in the oiled beach. The microbial PAH degradation potentials of both beaches, were tested in mesocosms. Mesocosms were constructed in glass columns using sands with native microbial communities, circulated with artificial sea water and challenged with a mixture of PAHs. The low-molecular weight PAHs, fluorene and naphthalene, showed rapid depletion in all mesocosms while the high-molecular weight benzo[α]pyrene was not degraded by either microbial community. Both the heavily oiled and the non-impacted coastal communities showed little variation in their biodegradation ability for low molecular weight PAHs. Massively-parallel sequencing of 16S rRNA genes from mesocosm DNA showed that known PAH degraders and genera frequently associated with oil hydrocarbon degradation represented a major portion of the bacterial community. The observed similar response by microbial communities from beaches with a different recent history of oil exposure suggests that Gulf Coast beach communities are primed for PAH

  3. Hydrocarbon-Degrading Bacteria Exhibit a Species-Specific Response to Dispersed Oil while Moderating Ecotoxicity

    Science.gov (United States)

    Overholt, Will A.; Marks, Kala P.; Romero, Isabel C.; Hollander, David J.; Snell, Terry W.

    2015-01-01

    The Deepwater Horizon blowout in April 2010 represented the largest accidental marine oil spill and the largest release of chemical dispersants into the environment to date. While dispersant application may provide numerous benefits to oil spill response efforts, the impacts of dispersants and potential synergistic effects with crude oil on individual hydrocarbon-degrading bacteria are poorly understood. In this study, two environmentally relevant species of hydrocarbon-degrading bacteria were utilized to quantify the response to Macondo crude oil and Corexit 9500A-dispersed oil in terms of bacterial growth and oil degradation potential. In addition, specific hydrocarbon compounds were quantified in the dissolved phase of the medium and linked to ecotoxicity using a U.S. Environmental Protection Agency (EPA)-approved rotifer assay. Bacterial treatment significantly and drastically reduced the toxicity associated with dispersed oil (increasing the 50% lethal concentration [LC50] by 215%). The growth and crude oil degradation potential of Acinetobacter were inhibited by Corexit by 34% and 40%, respectively; conversely, Corexit significantly enhanced the growth of Alcanivorax by 10% relative to that in undispersed oil. Furthermore, both bacterial strains were shown to grow with Corexit as the sole carbon and energy source. Hydrocarbon-degrading bacterial species demonstrate a unique response to dispersed oil compared to their response to crude oil, with potentially opposing effects on toxicity. While some species have the potential to enhance the toxicity of crude oil by producing biosurfactants, the same bacteria may reduce the toxicity associated with dispersed oil through degradation or sequestration. PMID:26546426

  4. Integration of geophysical, geochemical and microbiological data for a comprehensive small-scale characterization of an aged LNAPL-contaminated site.

    Science.gov (United States)

    Arato, Alessandro; Wehrer, Markus; Biró, Borbala; Godio, Alberto

    2014-01-01

    Characterization of aged hydrocarbon-contaminated sites is often a challenge due to the heterogeneity of subsurface conditions. Geoelectrical methods can aid in the characterization of such sites due to their non-invasive nature, but need to be supported by geochemical and microbiological data. In this study, a combination of respective methods was used to characterize an aged light non-aqueous phase liquid-contaminated site, which was the scene of a crude oil blow-out in 1994. As a consequence, a significant amount of crude oil was released into the subsurface. Complex resistivity has been acquired, both along single boreholes and in cross-hole configuration, in a two-borehole test site addressed with electrodes, to observe the electrical behaviour at the site over a two-year period (2010-2011). Geoelectrical response has been compared to results of the analysis of hydrocarbon contamination in soil and groundwater samples. Geochemical parameters of groundwater have been observed by collecting samples in a continuous multi-channel tubing (CMT) piezometer system. We have also performed a biological characterization on soil samples by drilling new boreholes close to the monitoring wells. Particular attention has been given to the characterization of the smear zone that is the sub-soil zone affected by the seasonal groundwater fluctuations. In the smear zone, trapped hydrocarbons were present, serving as organic substrate for chemical and biological degradation, as was indicated by an increase of microbial biomass and activity as well as ferrogenic-sulfidogenic conditions in the smear zone. The results show a good agreement between the intense electrical anomaly and the peaks of total organic matter and degradation by-products, particularly enhanced in the smear zone.

  5. An approach for estimating toxic releases of H2S-containing natural gas.

    Science.gov (United States)

    Jianwen, Zhang; Da, Lei; Wenxing, Feng

    2014-01-15

    China is well known being rich in sulfurous natural gas with huge deposits widely distributed all over the country. Due to the toxic nature, the release of hydrogen sulfide-containing natural gas from the pipelines intends to impose serious threats to the human, society and environment around the release sources. CFD algorithm is adopted to simulate the dispersion process of gas, and the results prove that Gaussian plume model is suitable for determining the affected region of the well blowout of sulfide hydrogen-containing natural gas. In accordance with the analysis of release scenarios, the present study proposes a new approach for estimating the risk of hydrogen sulfide poisoning hazards, as caused by sulfide-hydrogen-containing natural gas releases. Historical accident-statistical data from the EGIG (European Gas Pipeline Incident Data Group) and the Britain Gas Transco are integrated into the approach. Also, the dose-load effect is introduced to exploit the hazards' effects by two essential parameters - toxic concentration and exposure time. The approach was applied to three release scenarios occurring on the East-Sichuan Gas Transportation Project, and the individual risk and societal risk are classified and discussed. Results show that societal risk varies significantly with different factors, including population density, distance from pipeline, operating conditions and so on. Concerning the dispersion process of hazardous gas, available safe egress time was studied from the perspective of individual fatality risks. The present approach can provide reliable support for the safety management and maintenance of natural gas pipelines as well as evacuations that may occur after release incidents.

  6. A survey of microbial community diversity in marine sediments impacted by petroleum hydrocarbons from the Gulf of Mexico and Atlantic shorelines, Texas to Florida

    Science.gov (United States)

    Lisle, John T.; Stellick, Sarah H.

    2011-01-01

    Microbial community genomic DNA was extracted from sediment samples collected along the Gulf of Mexico and Atlantic coasts from Texas to Florida. Sample sites were identified as being ecologically sensitive and (or) as having high potential of being impacted by Macondo-1 (M-1) well oil from the Deepwater Horizon blowout. The diversity within the microbial communities associated with the collected sediments provides a baseline dataset to which microbial community-diversity data from impacted sites could be compared. To determine the microbial community diversity in the samples, genetic fingerprints were generated and compared. Specific sequences within the community genomic DNA were first amplified using the polymerase chain reaction (PCR) with a primer set that provides possible resolution to the species level. A second nested PCR was performed on the primary PCR products using a primer set on which a GC-clamp was attached to one of the primers. The nested PCR products were separated using denaturing-gradient gel electrophoresis (DGGE) that resolves the nested PCR products based on sequence dissimilarities (or similarities), forming a genomic fingerprint of the microbial diversity within the respective samples. Samples with similar fingerprints were grouped and compared to oil-fingerprint data from the same sites (Rosenbauer and others, 2011). The microbial community fingerprints were generally grouped into sites that had been shown to contain background concentrations of non-Deepwater Horizon oil. However, these groupings also included sites where no oil signature was detected. This report represents some of the first information on naturally occurring microbial communities in sediment from shorelines along the Gulf of Mexico and Atlantic coasts from Texas to Florida.

  7. Using Information Processing Techniques to Forecast, Schedule, and Deliver Sustainable Energy to Electric Vehicles

    Science.gov (United States)

    Pulusani, Praneeth R.

    As the number of electric vehicles on the road increases, current power grid infrastructure will not be able to handle the additional load. Some approaches in the area of Smart Grid research attempt to mitigate this, but those approaches alone will not be sufficient. Those approaches and traditional solution of increased power production can result in an insufficient and imbalanced power grid. It can lead to transformer blowouts, blackouts and blown fuses, etc. The proposed solution will supplement the ``Smart Grid'' to create a more sustainable power grid. To solve or mitigate the magnitude of the problem, measures can be taken that depend on weather forecast models. For instance, wind and solar forecasts can be used to create first order Markov chain models that will help predict the availability of additional power at certain times. These models will be used in conjunction with the information processing layer and bidirectional signal processing components of electric vehicle charging systems, to schedule the amount of energy transferred per time interval at various times. The research was divided into three distinct components: (1) Renewable Energy Supply Forecast Model, (2) Energy Demand Forecast from PEVs, and (3) Renewable Energy Resource Estimation. For the first component, power data from a local wind turbine, and weather forecast data from NOAA were used to develop a wind energy forecast model, using a first order Markov chain model as the foundation. In the second component, additional macro energy demand from PEVs in the Greater Rochester Area was forecasted by simulating concurrent driving routes. In the third component, historical data from renewable energy sources was analyzed to estimate the renewable resources needed to offset the energy demand from PEVs. The results from these models and components can be used in the smart grid applications for scheduling and delivering energy. Several solutions are discussed to mitigate the problem of overloading

  8. Going flat out : Collin Morris, a former roughneck-turned inventor, develops a radically different form of coiled tubing

    Energy Technology Data Exchange (ETDEWEB)

    Byfield, M.

    2009-11-15

    This article described a radically reshaped coiled tubing product developed by an engineer with CJS Coiled Tubing Supply Ltd. The method encapsulates multiple conduits and electric wires within a single coiled tubing umbilical. The product is manufactured in Texas where coiled tubing strings are braided and encased within a wrapping. The strings have to be braided to maintain uniform lengths when the tubing is spooled. CJS has developed a reputation as a technical coiled tubing problem solver, particularly for low-pressure gas wells where produced water must be removed in order to avoid build up. Round pipe is particularly difficult to braid if the various conduits are of different sizes and materials. The CJS solution is called FLATpak in which multiple conduits sit side by side, encased within a rectangular matrix of thermo plastic. Several configurations of conduit are possible, including various diameters and different electric wire. FLATpak is pressure-extruded as a single piece. The rectangular product coils tighter on a coiled tubing spool than round pipe, thereby reducing transportation costs. Steel blowout preventer (BOP) rams can be switched easily to the new shape as long as the rectangular form is solid and rounded at the corners. Many producers recognize the need to deploy artificial lift systems in low-rate gas wells. CJS has installed 30 permanent FLATpak systems in Canada, more than 10 in the United States, and is adding 4 or 5 more per month. CJS is also working to proof its umbilicals for higher pressures and temperatures, for possible offshore potential. 2 figs.

  9. The polycyclic aromatic hydrocarbon degradation potential of Gulf of Mexico native coastal microbial communities after the Deepwater Horizon oil spill.

    Science.gov (United States)

    Kappell, Anthony D; Wei, Yin; Newton, Ryan J; Van Nostrand, Joy D; Zhou, Jizhong; McLellan, Sandra L; Hristova, Krassimira R

    2014-01-01

    The Deepwater Horizon (DWH) blowout resulted in oil transport, including polycyclic aromatic hydrocarbons (PAHs) to the Gulf of Mexico shoreline. The microbial communities of these shorelines are thought to be responsible for the intrinsic degradation of PAHs. To investigate the Gulf Coast beach microbial community response to hydrocarbon exposure, we examined the functional gene diversity, bacterial community composition, and PAH degradation capacity of a heavily oiled and non-oiled beach following the oil exposure. With a non-expression functional gene microarray targeting 539 gene families, we detected 28,748 coding sequences. Of these sequences, 10% were uniquely associated with the severely oil-contaminated beach and 6.0% with the non-oiled beach. There was little variation in the functional genes detected between the two beaches; however the relative abundance of functional genes involved in oil degradation pathways, including polycyclic aromatic hydrocarbons (PAHs), were greater in the oiled beach. The microbial PAH degradation potentials of both beaches, were tested in mesocosms. Mesocosms were constructed in glass columns using sands with native microbial communities, circulated with artificial sea water and challenged with a mixture of PAHs. The low-molecular weight PAHs, fluorene and naphthalene, showed rapid depletion in all mesocosms while the high-molecular weight benzo[α]pyrene was not degraded by either microbial community. Both the heavily oiled and the non-impacted coastal communities showed little variation in their biodegradation ability for low molecular weight PAHs. Massively-parallel sequencing of 16S rRNA genes from mesocosm DNA showed that known PAH degraders and genera frequently associated with oil hydrocarbon degradation represented a major portion of the bacterial community. The observed similar response by microbial communities from beaches with a different recent history of oil exposure suggests that Gulf Coast beach communities are

  10. Evidence of lasting impact of the Deepwater Horizon oil spill on a deep Gulf of Mexico coral community

    Directory of Open Access Journals (Sweden)

    Pen-Yuan Hsing

    2013-12-01

    Full Text Available Abstract A coral community 11 km southwest of the site of the Deepwater Horizon blowout at 1,370 m water depth was discovered 3.5 months after the well was capped on 3 November 2010. Gorgonian corals at the site were partially covered by a brown flocculent material (floc that contained hydrocarbons fingerprinted to the oil spill. Here we quantify the visible changes to the corals at this site during five visits over 17 months by digitizing images of individual branches of each colony and categorizing their condition. Most of the floc visible in November 2010 was absent from the corals by the third visit in March 2011, and there was a decrease in the median proportions of the colonies showing obvious signs of impact after the first visit. During our second visit in 2010, about six weeks after the first, we documented the onset of hydroid colonization (a sign of coral deterioration on impacted coral branches that increased over the remainder of the study. Hydroid colonization of impacted portions of coral colonies by the last visit in March 2012 correlated positively with the proportion of the colony covered by floc during the first two visits in late 2010. Similarly, apparent recovery of impacted portions of the coral by March 2012 correlated negatively with the proportion of the coral covered with floc in late 2010. A notable feature of the impact was its patchy nature, both within and among colonies, suggesting that the impacting agent was not homogeneously dispersed during initial contact with the corals. While the median level of obvious visible impact decreased over time, the onset of hydroid colonization and the probability of impacts that were not visually obvious suggest that future visits may reveal additional deterioration in the condition of these normally long-lived corals.

  11. The 3-Dimensional Inner and Outer Structure of Ejecta Around Eta Carinae as Detected by the STIS

    Science.gov (United States)

    Ishibashi, Kazunori; Fisher, Richard R. (Technical Monitor)

    2000-01-01

    The HST/STIS instrument was used successfully to perform a complete mapping of the Homunculus nebula at two wavelength ranges including H-alpha and H-beta with a spectral resolving power of about 5000 and a spatial resolution of 0.1". The individual spectra were merged to synthesize three-dimensional data cubes that contain a set of images of Eta Car with spatial resolution of 0.10 to 0.251, sliced at velocity increment of 10 -- 30 km/s. For the first time this unique method allows us to diagnose the origin of intrinsic narrow emission structure of the nebula with high spatial and velocity resolution. Our initial analysis revealed the inner emission structure appeared to trace an elongated bipolar shell (possibly other shells as well) with a scale size of an arcsecond (i.e., "little homunculus in the Homunculus"). Furthermore, the mapping data cube revealed that the "fan" or "paddle" -- often referred as the source of peculiar blue-shifted intrinsic emissions including the Strontium cloud -- is not the source of intrinsic emissions. The fan is not even a part of the equatorial disk, but is spatially separated from the peculiar emission structure. Indeed we suggest that the fan is a surface of the Northwest lobe, possibly revealed by a blowout of the equatorial disk. We will use a number of visualization techniques (tomographic animations and simple 3-D models) to show these structures. These new results have strong impact upon future numerical modelings of the Homunculus nebula and of understanding of the evolution of the ejecta powered by the central source(s).

  12. CATALYTIC COMBUSTION OF METHANE OVER Pt/γ-Al2O3 IN MICRO-COMBUSTOR WITH DETAILED CHEMICAL KINETIC MECHANISMS

    Directory of Open Access Journals (Sweden)

    JUNJIE CHEN

    2014-11-01

    Full Text Available Micro-scale catalytic combustion characteristics and heat transfer processes of preheated methane-air mixtures (φ = 0.4 in the plane channel were investigated numerically with detailed chemical kinetic mechanisms. The plane channel of length L = 10.0 mm, height H =1.0 mm and wall thickness δ = 0.1 mm, which inner horizontal surfaces contained Pt/γ-Al2O3 catalyst washcoat. The computational results indicate that the presence of the gas phase reactions extends mildly the micro-combustion stability limits at low and moderate inlet velocities due to the strong flames establishment, and have a more profound effect on extending the high-velocity blowout limits by allowing for additional heat release originating mainly from the incomplete CH4 gas phase oxidation in the plane channel. When the same mass flow rate (ρin × Vin is considered, the micro-combustion stability limits at p: 0.1 MPa are much narrower than at p: 0.6 MPa due to both gas phase and catalytic reaction activities decline with decreasing pressure. Catalytic micro-combustor can achieve stable combustion at low solid thermal conductivity ks < 0.1 W∙m-1•K-1, while the micro-combustion extinction limits reach their larger extent for the higher thermal conductivity ks = 20.0-100.0 W∙m-1•K-1. The existence of surface radiation heat transfers significantly effects on the micro-combustion stability limits and micro-combustors energy balance. Finally, gas phase combustion in catalytic micro-combustors can be sustained at the sub-millimeter scale (plane channel height of 0.25 mm.

  13. Field observations of artificial sand and oil agglomerates

    Science.gov (United States)

    Dalyander, Patricia (Soupy); Long, Joseph W.; Plant, Nathaniel G.; McLaughlin, Molly R.; Mickey, Rangley C.

    2015-01-01

    Oil that comes into the surf zone following spills, such as occurred during the 2010 Deepwater Horizon (DWH) blowout, can mix with local sediment to form heavier-than-water sand and oil agglomerates (SOAs), at times in the form of mats a few centimeters thick and tens of meters long. Smaller agglomerates that form in situ or pieces that break off of larger mats, sometimes referred to as surface residual balls (SRBs), range in size from sand-sized grains to patty-shaped pieces several centimeters (cm) in diameter. These mobile SOAs can cause beach oiling for extended periods following the spill, on the scale of years as in the case of DWH. Limited research, including a prior effort by the U.S. Geological Survey (USGS) investigating SOA mobility, alongshore transport, and seafloor interaction using numerical model output, focused on the physical dynamics of SOAs. To address this data gap, we constructed artificial sand and oil agglomerates (aSOAs) with sand and paraffin wax to mimic the size and density of genuine SOAs. These aSOAs were deployed in the nearshore off the coast of St. Petersburg, Florida, during a field experiment to investigate their movement and seafloor interaction. This report presents the methodology for constructing aSOAs and describes the field experiment. Data acquired during the field campaign, including videos and images of aSOA movement in the nearshore (1.5-meter and 0.5-meter water depth) and in the swash zone, are also presented in this report.

  14. Investigation for the improvement of starting-up; Investigacion para la Mejora del Arranque con Explosivos en los Talleres de Sutirage en Capas Grisuosas

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    Win this investigation it is intended to develop new techniques and blasting procedures for sub level caving in underground coal mines, so that technical and economical results reached to date, including the safety aspects, could be improved. Concretely it is intended: - To optimise blasting procedures, itemizing in each situation through adequate shot designs, and - To develop some confinement techniques of the explosive that permits to improve its efficiency preserving safety against fire damp and coal powder. Following recommendations concerning the current permitted explosives and fittings utilisation in caving shots, are obtained. - Types of Explosive: The most recommendable explosive in this type of blasts is the Type III (20 SR). - Diameters of cartridges: It is recommended the use of this explosive in diameters of 32 or higher. - Permitted detonating cord: The use of the cord is considered essential with explosives of 26 mm, and highly recommendable with any permitted explosive. - Permitted detonators: It has not been verified any difference using one or two detonators in the blasting charge. - Total charge in the borehole: with regard to this item, following considerations must be settled: 1. It has been assayed the explosive Type III in load densities greater (1350 g/m) than the currently used (750 g/m) or (1000 g/m), corresponding to continuous explosive load in cartridges of 36, 26 and 32 mm, respectively. 2. Considering tests with detonating cord only, no ignition took place in the tests of coal mortar with slot. 3. Charges up to 1600 grams of explosive by ton of coal have been tried, what would surpass in more than six times the specific regular charges used in different exploitations. 4. It does not exist any study that demonstrate the influence of the length of the load with the possibility of ignition by blowouts, or intermediate nude charges in the borehole. 5. The possibility of obtaining a nude detonation of explosive in caving greater than 1

  15. Physical processes at work in sub-30 fs, PW laser pulse-driven plasma accelerators: Towards GeV electron acceleration experiments at CILEX facility

    Science.gov (United States)

    Beck, A.; Kalmykov, S. Y.; Davoine, X.; Lifschitz, A.; Shadwick, B. A.; Malka, V.; Specka, A.

    2014-03-01

    Optimal regimes and physical processes at work are identified for the first round of laser wakefield acceleration experiments proposed at a future CILEX facility. The Apollon-10P CILEX laser, delivering fully compressed, near-PW-power pulses of sub-25 fs duration, is well suited for driving electron density wakes in the blowout regime in cm-length gas targets. Early destruction of the pulse (partly due to energy depletion) prevents electrons from reaching dephasing, limiting the energy gain to about 3 GeV. However, the optimal operating regimes, found with reduced and full three-dimensional particle-in-cell simulations, show high energy efficiency, with about 10% of incident pulse energy transferred to 3 GeV electron bunches with sub-5% energy spread, half-nC charge, and absolutely no low-energy background. This optimal acceleration occurs in 2 cm length plasmas of electron density below 1018 cm-3. Due to their high charge and low phase space volume, these multi-GeV bunches are tailor-made for staged acceleration planned in the framework of the CILEX project. The hallmarks of the optimal regime are electron self-injection at the early stage of laser pulse propagation, stable self-guiding of the pulse through the entire acceleration process, and no need for an external plasma channel. With the initial focal spot closely matched for the nonlinear self-guiding, the laser pulse stabilizes transversely within two Rayleigh lengths, preventing subsequent evolution of the accelerating bucket. This dynamics prevents continuous self-injection of background electrons, preserving low phase space volume of the bunch through the plasma. Near the end of propagation, an optical shock builds up in the pulse tail. This neither disrupts pulse propagation nor produces any noticeable low-energy background in the electron spectra, which is in striking contrast with most of existing GeV-scale acceleration experiments.

  16. Physical processes at work in sub-30 fs, PW laser pulse-driven plasma accelerators: Towards GeV electron acceleration experiments at CILEX facility

    Energy Technology Data Exchange (ETDEWEB)

    Beck, A., E-mail: beck@llr.in2p3.fr [Laboratoire Leprince-Ringuet – École Polytechnique, CNRS-IN2P3, Palaiseau 91128 (France); Kalmykov, S.Y., E-mail: skalmykov2@unl.edu [Department of Physics and Astronomy, University of Nebraska – Lincoln, Nebraska 68588-0299 (United States); Davoine, X. [CEA, DAM, DIF, Arpajon F-91297 (France); Lifschitz, A. [Laboratoire d' Optique Appliquée, ENSTA ParisTech-CNRS UMR7639-École Polytechnique, Palaiseau 91762 (France); Shadwick, B.A. [Department of Physics and Astronomy, University of Nebraska – Lincoln, Nebraska 68588-0299 (United States); Malka, V. [Laboratoire d' Optique Appliquée, ENSTA ParisTech-CNRS UMR7639-École Polytechnique, Palaiseau 91762 (France); Specka, A. [Laboratoire Leprince-Ringuet – École Polytechnique, CNRS-IN2P3, Palaiseau 91128 (France)

    2014-03-11

    Optimal regimes and physical processes at work are identified for the first round of laser wakefield acceleration experiments proposed at a future CILEX facility. The Apollon-10P CILEX laser, delivering fully compressed, near-PW-power pulses of sub-25 fs duration, is well suited for driving electron density wakes in the blowout regime in cm-length gas targets. Early destruction of the pulse (partly due to energy depletion) prevents electrons from reaching dephasing, limiting the energy gain to about 3 GeV. However, the optimal operating regimes, found with reduced and full three-dimensional particle-in-cell simulations, show high energy efficiency, with about 10% of incident pulse energy transferred to 3 GeV electron bunches with sub-5% energy spread, half-nC charge, and absolutely no low-energy background. This optimal acceleration occurs in 2 cm length plasmas of electron density below 10{sup 18} cm{sup −3}. Due to their high charge and low phase space volume, these multi-GeV bunches are tailor-made for staged acceleration planned in the framework of the CILEX project. The hallmarks of the optimal regime are electron self-injection at the early stage of laser pulse propagation, stable self-guiding of the pulse through the entire acceleration process, and no need for an external plasma channel. With the initial focal spot closely matched for the nonlinear self-guiding, the laser pulse stabilizes transversely within two Rayleigh lengths, preventing subsequent evolution of the accelerating bucket. This dynamics prevents continuous self-injection of background electrons, preserving low phase space volume of the bunch through the plasma. Near the end of propagation, an optical shock builds up in the pulse tail. This neither disrupts pulse propagation nor produces any noticeable low-energy background in the electron spectra, which is in striking contrast with most of existing GeV-scale acceleration experiments.

  17. An Experimental and Computational Study on Soot Formation in a Coflow Jet Flame Under Microgravity and Normal Gravity

    Science.gov (United States)

    Ma, Bin; Cao, Su; Giassi, Davide; Stocker, Dennis P.; Takahashi, Fumiaki; Bennett, Beth Anne V.; Smooke, Mitchell D.; Long, Marshall B.

    2014-01-01

    Upon the completion of the Structure and Liftoff in Combustion Experiment (SLICE) in March 2012, a comprehensive and unique set of microgravity coflow diffusion flame data was obtained. This data covers a range of conditions from weak flames near extinction to strong, highly sooting flames, and enabled the study of gravitational effects on phenomena such as liftoff, blowout and soot formation. The microgravity experiment was carried out in the Microgravity Science Glovebox (MSG) on board the International Space Station (ISS), while the normal gravity experiment was performed at Yale utilizing a copy of the flight hardware. Computational simulations of microgravity and normal gravity flames were also carried out to facilitate understanding of the experimental observations. This paper focuses on the different sooting behaviors of CH4 coflow jet flames in microgravity and normal gravity. The unique set of data serves as an excellent test case for developing more accurate computational models.Experimentally, the flame shape and size, lift-off height, and soot temperature were determined from line-of-sight flame emission images taken with a color digital camera. Soot volume fraction was determined by performing an absolute light calibration using the incandescence from a flame-heated thermocouple. Computationally, the MC-Smooth vorticity-velocity formulation was employed to describe the chemically reacting flow, and the soot evolution was modeled by the sectional aerosol equations. The governing equations and boundary conditions were discretized on an axisymmetric computational domain by finite differences, and the resulting system of fully coupled, highly nonlinear equations was solved by a damped, modified Newtons method. The microgravity sooting flames were found to have lower soot temperatures and higher volume fraction than their normal gravity counterparts. The soot distribution tends to shift from the centerline of the flame to the wings from normal gravity to

  18. THE INNER DISK STRUCTURE, DISK-PLANET INTERACTIONS, AND TEMPORAL EVOLUTION IN THE β PICTORIS SYSTEM: A TWO-EPOCH HST/STIS CORONAGRAPHIC STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Apai, Dániel; Schneider, Glenn [Department of Astronomy and Steward Observatory, The University of Arizona, Tucson, AZ 85721 (United States); Grady, Carol A. [Eureka Scientific, 2452 Delmer, Suite 100, Oakland CA 96002 (United States); Wyatt, Mark C. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Lagrange, Anne-Marie [Université Grenoble Alpes, IPAG, F-38000, Grenoble (France); Kuchner, Marc J.; Stark, Christopher J. [NASA Goddard Space Flight Center, Exoplanets and Stellar Astrophysics Laboratory, Code 667, Greenbelt, MD 20771 (United States); Lubow, Stephen H., E-mail: apai@arizona.edu [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

    2015-02-20

    We present deep Hubble Space Telescope/Space Telescope Imaging Spectrograph coronagraphic images of the β Pic debris disk obtained at two epochs separated by 15 yr. The new images and the re-reduction of the 1997 data provide the most sensitive and detailed views of the disk at optical wavelengths as well as the yet smallest inner working angle optical coronagraphic image of the disk. Our observations characterize the large-scale and inner-disk asymmetries and we identify multiple breaks in the disk radial surface brightness profile. We study in detail the radial and vertical disk structure and show that the disk is warped. We explore the disk at the location of the β Pic b super-Jupiter and find that the disk surface brightness slope is continuous between 0.''5 and 2.''0, arguing for no change at the separations where β Pic b orbits. The two epoch images constrain the disk's surface brightness evolution on orbital and radiation pressure blow-out timescales. We place an upper limit of 3% on the disk surface brightness change between 3'' and 5'', including the locations of the disk warp, and the CO and dust clumps. We discuss the new observations in the context of high-resolution multi-wavelength images and divide the disk asymmetries in two groups: axisymmetric and non-axisymmetric. The axisymmetric structures (warp, large-scale butterfly, etc.) are consistent with disk structure models that include interactions of a planetesimal belt and a non-coplanar giant planet. The non-axisymmetric features, however, require a different explanation.

  19. 大容量高速限流开关的设计与试验研究%Design and Test Study of Large Capacity High Speed Current Limit Switch

    Institute of Scientific and Technical Information of China (English)

    李健; 朱峰

    2011-01-01

    针对现有保护设备难以满足大容量电力系统短路保护要求的问题,研制了一种基于爆炸活塞式高速开断器和灭弧熔断器的混合型限流保护装置,设计了额定640V/2500A的工程样机,并进行了高速开断器的分断试验和整机的限流试验。试验结果表明,该保护装置限流效果显著,全分断时fHJ仪为2.5ms,大大提高了电力系统的安全性。%Aiming at the problem that the existing protection equipment is difficult to meet large capacity power system short circuit protective requirements problem, this paper researched a kind of high speed break-off device based on explosive piston type and arc blow-out fuse mixed type, current limit protection device, designing rated voltage 640 V/2 500 A engineering sample machine. The break-off test and whole machine current limit test were carried out for high speed breaker. Test result shows that the protective device current limit effect is obvious and the total break-offtime is only 2.5 ms, which greatly raises safety of the power system.

  20. A multi-wavelength survey of obscured and reddened quasars at the peak of galaxy formation

    Science.gov (United States)

    Alexandroff, Rachael

    2017-01-01

    While in the nearby universe the unification model seems firmly established, we are now seeing hints that at the peak of quasar activity and black hole growth (z~2.5) both obscured and reddened quasars may represent not just a specific quasar orientation but instead a unique stage of quasar evolution. Our group has developed several observational techniques to identify obscured and highly reddened quasars at z~2.5 using a combination of the SDSS spectroscopy and WISE photometry. Our sample contains objects with some of the most extreme ionized gas velocities observed (> 5000 km/s), indicating wind speeds too large to be contained by the galaxy potential though they are radio quiet. I will present both our sample selection and initial results from multi-wavelength follow-up of this sample using near-infrared spectroscopy, Keck spectropolarimentry and the VLA to test the AGN unification model and search for evidence of galaxy-wide quasar winds. High levels of polarized light (reaching ~20% of the total continuum emission in some cases) and changes in the polarization fraction and position angle across emission lines may argue for the presence of dusty outflows in our objects. This is supported by evidence from stacking analysis in the radio that presents a correlation between the observed outflow speeds in ionized gas (as measured by [OIII]) and the radio luminosity—arguing for a wind origin for the radio emission in these objects as well. The most extreme of these objects may thus represent the “blowout phase” of AGN evolution that proceeds or accompanies the cessation of star formation in the host galaxy due to the effects of radiatively-driven quasar driven winds.

  1. Ultimately Reliable Pyrotechnic Systems

    Science.gov (United States)

    Scott, John H.; Hinkel, Todd

    2015-01-01

    This paper presents the methods by which NASA has designed, built, tested, and certified pyrotechnic devices for high reliability operation in extreme environments and illustrates the potential applications in the oil and gas industry. NASA's extremely successful application of pyrotechnics is built upon documented procedures and test methods that have been maintained and developed since the Apollo Program. Standards are managed and rigorously enforced for performance margins, redundancy, lot sampling, and personnel safety. The pyrotechnics utilized in spacecraft include such devices as small initiators and detonators with the power of a shotgun shell, detonating cord systems for explosive energy transfer across many feet, precision linear shaped charges for breaking structural membranes, and booster charges to actuate valves and pistons. NASA's pyrotechnics program is one of the more successful in the history of Human Spaceflight. No pyrotechnic device developed in accordance with NASA's Human Spaceflight standards has ever failed in flight use. NASA's pyrotechnic initiators work reliably in temperatures as low as -420 F. Each of the 135 Space Shuttle flights fired 102 of these initiators, some setting off multiple pyrotechnic devices, with never a failure. The recent landing on Mars of the Opportunity rover fired 174 of NASA's pyrotechnic initiators to complete the famous '7 minutes of terror.' Even after traveling through extreme radiation and thermal environments on the way to Mars, every one of them worked. These initiators have fired on the surface of Titan. NASA's design controls, procedures, and processes produce the most reliable pyrotechnics in the world. Application of pyrotechnics designed and procured in this manner could enable the energy industry's emergency equipment, such as shutoff valves and deep-sea blowout preventers, to be left in place for years in extreme environments and still be relied upon to function when needed, thus greatly enhancing

  2. 不规则多面体高保温玻璃采光顶施工技术%Construction of Irregular Polyhedral Thermo-insulating Glass Daylighting Roof

    Institute of Scientific and Technical Information of China (English)

    胡龙伟; 田砾; 赵铁军

    2014-01-01

    The daylighting roof with high thermo-insulating glass is adopted increasingly in large-scale public building because of its great visual impact and artistic expressive force along with day lighting and heat preservation. However,if the construction precision is not enough, leakage of water, glass blowout and other question will stand out easily. The construction technology of S-G eco-park experience center were studied in this paper, corresponding technical measure of such an irregular polyhedral thermo-insulating and glass daylighting roof can ensure the installation accuracy of the glass within mm order of magnitude. Specialized construction technology can be summed up base on this engineering and can be utilized in similar projects.%高保温采光屋顶在大型公共建筑中越来越多地得到应用,因为其具有极强的视觉冲击力和艺术表现力的同时,具有采光、保温等诸多功能。但如果施工精度不高,则易引起渗漏水、玻璃爆裂等问题。针对国内某生态园的体验中心不规则多面体高保温采光屋顶的施工进行了研究,相应的施工工艺及技术措施可以保证高保温玻璃安装精度控制在mm数量级。在此基础上总结了不规则多面体玻璃采光顶专用施工技术,对保证类似工程的施工精度具有一定的参考价值。

  3. 建设江阴进口食品超市可行性调研报告%The construction of the Jiangyin imported food supermarket feasibility research report

    Institute of Scientific and Technical Information of China (English)

    魏颖; 吴陈君

    2014-01-01

    随着人们的消费观念和消费档次逐渐提高和升级,越来越追求高品质的生活质量。江阴经济雄居全国百强县之首,成为城镇经济的领航者,快速从过去的温饱型向营养型、健康型、品牌型转变。进口食品以其上乘品质、营养健康、新奇时尚受到了越来越多不同年龄层次、不同消费层次的人群的青睐。专家分析,未来十年是中国进口食品高速发展期,值此契机进入进口食品行业,开创江阴进口食品消费市场,未来时期将是“井喷式”增长,前景非常广阔。%People's consumption concept and consumption level gradually improve, more and more pursuit of high quality of life. Jiangyin economic rank among the country, become a leading urban economy, fast, subsistence from the past to nutritional, healthy model, brand type. Imported food has excellent quality, nutrition, health, are popular in different age groups. Expert analysis, in the next decade, China imported foods’ high speed development, on the occasion of the opportunity to enter import food industry, create Jiangyin’s imported food consumption market, future will be a"blowout"growth, prospects are very broad.

  4. Observations of bubbles in natural seep flares at MC 118 and GC 600 using in situ quantitative imaging

    Science.gov (United States)

    Wang, Binbin; Socolofsky, Scott A.; Breier, John A.; Seewald, Jeffrey S.

    2016-04-01

    This paper reports the results of quantitative imaging using a stereoscopic, high-speed camera system at two natural gas seep sites in the northern Gulf of Mexico during the Gulf Integrated Spill Research G07 cruise in July 2014. The cruise was conducted on the E/V Nautilus using the ROV Hercules for in situ observation of the seeps as surrogates for the behavior of hydrocarbon bubbles in subsea blowouts. The seeps originated between 890 and 1190 m depth in Mississippi Canyon block 118 and Green Canyon block 600. The imaging system provided qualitative assessment of bubble behavior (e.g., breakup and coalescence) and verified the formation of clathrate hydrate skins on all bubbles above 1.3 m altitude. Quantitative image analysis yielded the bubble size distributions, rise velocity, total gas flux, and void fraction, with most measurements conducted from the seafloor to an altitude of 200 m. Bubble size distributions fit well to lognormal distributions, with median bubble sizes between 3 and 4.5 mm. Measurements of rise velocity fluctuated between two ranges: fast-rising bubbles following helical-type trajectories and bubbles rising about 40% slower following a zig-zag pattern. Rise speed was uncorrelated with hydrate formation, and bubbles following both speeds were observed at both sites. Ship-mounted multibeam sonar provided the flare rise heights, which corresponded closely with the boundary of the hydrate stability zone for the measured gas compositions. The evolution of bubble size with height agreed well with mass transfer rates predicted by equations for dirty bubbles.

  5. Research on Information Extraction of Webpage Based on Text Tagging Attributes%基于文本标签属性的网页信息抽取方法研究

    Institute of Scientific and Technical Information of China (English)

    沈娜

    2016-01-01

    伴随着互联网的飞速发展,网络上的信息资源呈现出井喷态势,如何从海量的信息中抽取出自己需要的信息已经变得越发的困难。在分析现有Web信息抽取技术现状及面临的挑战的基础上,设计了一种基于文本标签属性的Web新闻信息抽取模型。主要介绍了基于标签的Web信息抽取技术的算法,给出了信息抽取的具体实现过程,对基于DOM树节点遍历的文本标签过滤算法进行了描述,并选取了主流的新闻网站进行了抽取实验,验证了算法的可行性。%With the rapid development of Internet, online information resources present a blowout situation. At the same time, it has become increasingly difficult to extract information from huge amounts of the information we need. Af-ter studying the existing Web information extraction technology and the challenges faced, we design a Web news infor-mation extraction model based on text tagging attribute. This paper mainly introduces the Web information extraction technology based on the attribute of text tag, presents the specific implementation process of information extraction, de-scribes the traversal algorithm of the filtering text labels based on DOM tree node, and chooses the mainstream news sites to carry out the extraction experiment and to verify the feasibility of the algorithm.

  6. Current Study on Choke and Kill Line Connector of Subsea BOP Stack%水下防喷器组节流压井管线插接器研究现状

    Institute of Scientific and Technical Information of China (English)

    侯国庆

    2016-01-01

    Choke and kill line connector is the key equipment of subsea blowout preventer stack, of which the core technology is mainly controlled by a few foreign BOP manufacturers. To guarantee our country's energy se-curity and protect our maritime rights and interests, and to accelerate the development of BOP stack with independ-ent intellectual property rights, the current study on common mechanical and Hydril, Radoil, AXON, Shaffer hy-draulic subsea BOP choke and kill line connector have been introduced, and their design features and advantages and disadvantages have been analyzed. Research on the product structure, sealing materials and locking mechanism should be strengthened during development of subsea BOP choke and kill line connector.%节流压井管线插接器是水下防喷器组的关键单元设备,其核心技术主要掌握在国外少数几个防喷器生产厂家.为保障我国能源安全和海洋权益,应加快开发具有自主知识产权的水下防喷器组.介绍了常用机械式和Hydril、Radoil、AXON及Shaffer液压式水下防喷器组节流压井管线插接器的研究现状,分析了它们的结构特点及优缺点.国内在开发水下防喷器组节流压井管线插接器时应在产品结构、 密封材料、 锁紧机构等方面加强研究.

  7. Use of safety case to accomplish with Brazilian regulations for drilling units; Uso de caso de seguranca para cumprir com as normas brasileiras para unidades de perfuracao: metodologia Bow Tie

    Energy Technology Data Exchange (ETDEWEB)

    Bardy, Mariana; Silveira, Paula Dias; Oliveira, Katia [Det Norske Veritas (DNV), Rio de Janeiro, RJ (Brazil). Risk Advisory

    2012-07-01

    The last accidents on the industry, mainly after BP accident in Texas City and Macondo blowout, showed and increased the importance of safety barriers on prevention of such events. The safety barriers can be identified in risk analysis studies such as Preliminary Hazard Analysis or HAZOP. But, the identification of safety barriers is not enough, it is necessary to maintain their integrity to guarantee that when demanded they work properly as expected. The methodology presented in this document aim to evaluate the integrity condition of safety barriers and their compliance with the project original characteristics using the Bow Tie and an audit process, and searching for actions that can guarantee the barriers integrity when demanded in a proactive way. The Bow Tie diagrams provide a graphic picture of accidental scenarios, join a relational perspective between event, cause, consequence and barriers, and additionally provide a clear view of possible threats and consequences related with events with high damage potential. The application of methodology described in this document is presented based on a case study related to an accidental release of flammable liquid due to dropped objects on the topside of an offshore unit. Among the benefits identified using this proposed methodology it can be highlighted the possibility to form an integrated overview of management system and of factors that can reduce losses. The Bow Tie diagram provides an overview of process accidents, in several different organization levels, and the integration between different areas responsible for management of different barriers groups. Complementing those diagrams with an audit process it can be determined the real image of company management system related to process safety, which make possible the identification of main points for improvement. (author)

  8. Metagenomic analysis of microbial consortium from natural crude oil that seeps into the marine ecosystem offshore Southern California.

    Science.gov (United States)

    Hawley, Erik R; Piao, Hailan; Scott, Nicole M; Malfatti, Stephanie; Pagani, Ioanna; Huntemann, Marcel; Chen, Amy; Glavina Del Rio, Tijana; Foster, Brian; Copeland, Alex; Jansson, Janet; Pati, Amrita; Tringe, Susannah; Gilbert, Jack A; Lorenson, Thomas D; Hess, Matthias

    2014-06-15

    Crude oils can be major contaminants of the marine ecosystem and microorganisms play a significant role in the degradation of its main constituents. To increase our understanding of the microbial hydrocarbon degradation process in the marine ecosystem, we collected crude oil from an active seep area located in the Santa Barbara Channel (SBC) and generated a total of about 52 Gb of raw metagenomic sequence data. The assembled data comprised ~500 Mb, representing ~1.1 million genes derived primarily from chemolithoautotrophic bacteria. Members of Oceanospirillales, a bacterial order belonging to the Deltaproteobacteria, recruited less than 2% of the assembled genes within the SBC metagenome. In contrast, the microbial community associated with the oil plume that developed in the aftermath of the Deepwater Horizon (DWH) blowout in 2010, was dominated by Oceanospirillales, which comprised more than 60% of the metagenomic data generated from the DWH oil plume. This suggests that Oceanospirillales might play a less significant role in the microbially mediated hydrocarbon conversion within the SBC seep oil compared to the DWH plume oil. We hypothesize that this difference results from the SBC oil seep being mostly anaerobic, while the DWH oil plume is aerobic. Within the Archaea, the phylum Euryarchaeota, recruited more than 95% of the assembled archaeal sequences from the SBC oil seep metagenome, with more than 50% of the sequences assigned to members of the orders Methanomicrobiales and Methanosarcinales. These orders contain organisms capable of anaerobic methanogenesis and methane oxidation (AOM) and we hypothesize that these orders - and their metabolic capabilities - may be fundamental to the ecology of the SBC oil seep.

  9. See Also:Mechanics of Cohesive-frictional MaterialsCopyright © 2004 John Wiley & Sons, Ltd.Get Sample CopyFree Online Trial -->Recommend to Your LibrarianSave Title to My ProfileSet E-Mail Alert Journal subnav -->var homepagelinks = new Array(new Array("Journal Home","/cgi-bin/jhome/3312",""),new Array("Issues","/cgi-bin/jtoc/3312/",""),new Array("Early View","/cgi-bin/jeview/3312/",""),new Array("News","/cgi-bin/jabout/3312/News.html","e"),new Array("","","s"),new Array("Product Information","/cgi-bin/jabout/3312/ProductInformation.html",""),new Array("Editorial Board","/cgi-bin/jabout/3312/EditorialBoard.html",""),new Array("For Authors","/cgi-bin/jabout/3312/ForAuthors.html",""),new Array("Subscribe","http://jws-edcv.wiley.com/jcatalog/JournalsCatalogOrder/JournalOrder?PRINT_ISSN=0363-9061",""),new Array("Advertise","/cgi-bin/jabout/3312/Advertise.html",""),new Array("Contact","/cgi-bin/jabout/3312/Contact.html",""),new Array("","","x"));writeJournalLinks("", "3312");Journal subnav -->journal info area -->journal info area --> Previous Issue | Next Issue >Volume 28, Issue12 (October 2004)Articles in the Current Issue:Research ArticleModelling poroelastic hollow cylinder experiments with realistic boundary conditions

    Science.gov (United States)

    Jourine, S.; Valkó, P. P.; Kronenberg, A. K.

    2004-10-01

    A general poroelastic solution for axisymmetrical plane strain problems with time dependent boundary conditions is developed in Laplace domain. Time-domain results are obtained using numerical inversion of the Laplace transform. Previously published solutions can be considered as special cases of the proposed solution. In particular, we could reproduce numerical results for solid and hollow poroelastic cylinders with suddenly applied load/pressure (Rice and Cleary, Rev. Geophys. Space Phys. 1976; 14:227; Schmitt, Tait and Spann, Int. J. Rock Mech. Min. Sci. 1993; 30:1057; Cui and Abousleiman, ASCE J. Eng. Mech. 2001; 127:391).The new solution is used to model laboratory tests on thick-walled hollow cylinders of Berea sandstone subjected to intensive pressure drawdown. In the experiments, pressure at the inner boundary of the hollow cylinder is observed to decline exponentially with a decay constant of 3-5 1/s.It is found that solutions with idealized step-function type inner boundary conditions overestimate the induced tensile radial stresses considerably. Although basic poroelastic phenomena can be modelled properly at long time following a stepwise change in pressure, realistic time varying boundary conditions predict actual rock behaviour better at early time. Experimentally observed axial stresses can be matched but appear to require different values for α and than are measured at long time.The proposed solution can be used to calculate the stress and pore pressure distributions around boreholes under infinite/finite boundary conditions. Prospective applications include investigating the effect of gradually changing pore pressure, modelling open-hole cavity completions, and describing the phenomenon of wellbore collapse (bridging) during oil or gas blowouts. Copyright

  10. Coexisting sea-based and land-based sources of contamination by PAHs in the continental shelf sediments of Coatzacoalcos River discharge area (Gulf of Mexico).

    Science.gov (United States)

    Ruiz-Fernández, Ana Carolina; Portela, Julián Mauricio Betancourt; Sericano, José Luis; Sanchez-Cabeza, Joan-Albert; Espinosa, Luisa Fernanda; Cardoso-Mohedano, José Gilberto; Pérez-Bernal, Libia Hascibe; Tinoco, Jesús Antonio Garay

    2016-02-01

    The oldest refinery and the major petrochemical complexes of Mexico are located in the lower reach of the Coatzacoalcos River, considered the most polluted coastal area of Mexico. A (210)Pb-dated sediment core, from the continental shelf of the Coatzacoalcos River, was studied to assess the contamination impact by the oil industry in the southern Gulf of Mexico. The sedimentary record showed the prevalence of petrogenic PAHs between 1950s and 1970s, a period during which waste discharges from the oil industry were not regulated. Later on, sediments exhibited higher contents of pyrogenic PAHs, attributed to the incineration of petrochemical industry wastes and recurrent wildfires in open dumpsites at the nearby swamps. The total concentration of the 16 EPA-priority PAHs indicated low levels of contamination (1000 ng g(-1)) during the late 1970s, most likely due to the major oil spill produced by the blowout of the Ixtoc-I offshore oil rig in deep waters of the southwestern Gulf of Mexico. Most of the PAH congeners did not show defined temporal trends but, according to a Factor Analysis, apparently have a common origin, probably waste released from the nearby oil industry. The only exceptions were the pyrogenic benzo(b)fluoranthene and benzo(a)pyrene, and the biogenic perylene, that showed increasing concentration trends with time, which we attributed to erosional input of contaminated soil from the catchment area. Our study confirmed chronic oil contamination in the Coatzacoalcos River coastal area from land based sources for more than 60 years (since 1950s).

  11. Comparative analysis of bacterial community-metagenomics in coastal Gulf of Mexico sediment microcosms following exposure to Macondo oil (MC252).

    Science.gov (United States)

    Koo, Hyunmin; Mojib, Nazia; Thacker, Robert W; Bej, Asim K

    2014-11-01

    The indigenous bacterial communities in sediment microcosms from Dauphin Island (DI), Petit Bois Island (PB) and Perdido Pass (PP) of the coastal Gulf of Mexico were compared following treatment with Macondo oil (MC252) using pyrosequencing and culture-based approaches. After quality-based trimming, 28,991 partial 16S rRNA sequence reads were analyzed by rarefaction, confirming that analyses of bacterial communities were saturated with respect to species diversity. Changes in the relative abundances of Proteobacteria, Bacteroidetes and Firmicutes played an important role in structuring bacterial communities in oil-treated sediments. Proteobacteria were dominant in oil-treated samples, whereas Firmicutes and Bacteroidetes were either the second or the third most abundant taxa. Tenericutes, members of which are known for oil biodegradation, were detected shortly after treatment, and continued to increase in DI and PP sediments. Multivariate statistical analyses (ADONIS) revealed significant dissimilarity of bacterial communities between oil-treated and untreated samples and among locations. In addition, a similarity percentage analysis showed the contribution of each species to the contrast between untreated and oil-treated samples. PCR amplification using DNA from pure cultures of Exiguobacterium,  Pseudoalteromonas,  Halomonas and Dyadobacter, isolated from oil-treated microcosm sediments, produced amplicons similar to polycyclic aromatic hydrocarbon-degrading genes. In the context of the 2010 Macondo blowout, the results from our study demonstrated that the indigenous bacterial communities in coastal Gulf of Mexico sediment microcosms responded to the MC252 oil with altered community structure and species composition. The rapid proliferation of hydrocarbonoclastic bacteria suggests their involvement in the degradation of the spilt oil in the Gulf of Mexico ecosystem.

  12. Pre-flare Coronal Jet and Evolutionary Phases of a Solar Eruptive Prominence Associated with the M1.8 Flare: SDO and RHESSI Observations

    Science.gov (United States)

    Joshi, Bhuwan; Kushwaha, Upendra; Veronig, Astrid M.; Cho, K.-S.

    2016-12-01

    We investigate the triggering, activation, and ejection of a solar eruptive prominence that occurred in a multi-polar flux system of active region NOAA 11548 on 2012 August 18 by analyzing data from the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory, the Reuven Ramaty High Energy Solar Spectroscopic Imager, and the Extreme Ultraviolet Imager/Sun Earth Connection Coronal and Heliospheric Investigation on board the Solar Terrestrial Relation Observatory. Prior to the prominence activation, we observed striking coronal activities in the form of a blowout jet, which is associated with the rapid eruption of a cool flux rope. Furthermore, the jet-associated flux rope eruption underwent splitting and rotation during its outward expansion. These coronal activities are followed by the prominence activation during which it slowly rises with a speed of ˜12 km s-1 while the region below the prominence emits gradually varying EUV and thermal X-ray emissions. From these observations, we propose that the prominence eruption is a complex, multi-step phenomenon in which a combination of internal (tether-cutting reconnection) and external (i.e., pre-eruption coronal activities) processes are involved. The prominence underwent catastrophic loss of equilibrium with the onset of the impulsive phase of an M1.8 flare, suggesting large-scale energy release by coronal magnetic reconnection. We obtained signatures of particle acceleration in the form of power-law spectra with hard electron spectral index (δ ˜ 3) and strong HXR footpoint sources. During the impulsive phase, a hot EUV plasmoid was observed below the apex of the erupting prominence that ejected in the direction of the prominence with a speed of ˜177 km s-1. The temporal, spatial, and kinematic correlations between the erupting prominence and the plasmoid imply that the magnetic reconnection supported the fast ejection of prominence in the lower corona.

  13. Are There Different Populations of Flux Ropes in the Solar Wind?

    Science.gov (United States)

    Janvier, M.; Démoulin, P.; Dasso, S.

    2014-07-01

    Flux ropes are twisted magnetic structures that can be detected by in-situ measurements in the solar wind. However, different properties of detected flux ropes suggest different types of flux-rope populations. As such, are there different populations of flux ropes? The answer is positive and is the result of the analysis of four lists of flux ropes, including magnetic clouds (MCs), observed at 1 AU. The in-situ data for the four lists were fitted with the same cylindrical force-free field model, which provides an estimate of the local flux-rope parameters such as its radius and orientation. Since the flux-rope distributions have a broad dynamic range, we went beyond a simple histogram analysis by developing a partition technique that uniformly distributes the statistical fluctuations across the radius range. By doing so, we found that small flux ropes with radius Rlaw distribution in contrast to the larger flux ropes (identified as MCs), which have a Gaussian-like distribution. Next, from four CME catalogs, we estimated the expected flux-rope frequency per year at 1 AU. We found that the predicted numbers are similar to the frequencies of MCs observed in-situ. However, we also found that small flux ropes are at least ten times too abundant to correspond to CMEs, even to narrow ones. Investigating the different possible scenarios for the origin of these small flux ropes, we conclude that these twisted structures can be formed by blowout jets in the low corona or in coronal streamers.

  14. Comparative analysis of bacterial community-metagenomics in coastal Gulf of Mexico sediment microcosms following exposure to Macondo oil (MC252)

    KAUST Repository

    Koo, Hyunmin

    2014-09-10

    The indigenous bacterial communities in sediment microcosms from Dauphin Island (DI), Petit Bois Island (PB) and Perdido Pass (PP) of the coastal Gulf of Mexico were compared following treatment with Macondo oil (MC252) using pyrosequencing and culture-based approaches. After quality-based trimming, 28,991 partial 16S rRNA sequence reads were analyzed by rarefaction, confirming that analyses of bacterial communities were saturated with respect to species diversity. Changes in the relative abundances of Proteobacteria, Bacteroidetes and Firmicutes played an important role in structuring bacterial communities in oil-treated sediments. Proteobacteria were dominant in oil-treated samples, whereas Firmicutes and Bacteroidetes were either the second or the third most abundant taxa. Tenericutes, members of which are known for oil biodegradation, were detected shortly after treatment, and continued to increase in DI and PP sediments. Multivariate statistical analyses (ADONIS) revealed significant dissimilarity of bacterial communities between oil-treated and untreated samples and among locations. In addition, a similarity percentage analysis showed the contribution of each species to the contrast between untreated and oil-treated samples. PCR amplification using DNA from pure cultures of Exiguobacterium,  Pseudoalteromonas,  Halomonas and Dyadobacter, isolated from oil-treated microcosm sediments, produced amplicons similar to polycyclic aromatic hydrocarbon-degrading genes. In the context of the 2010 Macondo blowout, the results from our study demonstrated that the indigenous bacterial communities in coastal Gulf of Mexico sediment microcosms responded to the MC252 oil with altered community structure and species composition. The rapid proliferation of hydrocarbonoclastic bacteria suggests their involvement in the degradation of the spilt oil in the Gulf of Mexico ecosystem.

  15. 水下溢油事故污染物输移扩散的数值模拟研究%Numerical simulation of pollutant transport and diffusion in underwater oil spill

    Institute of Scientific and Technical Information of China (English)

    廖国祥; 高振会

    2011-01-01

    Based on the analysis of the characteristics of different underwater accidents (e.g. Pipe line broke up, oil well blowout) and the pollutant transport processes in such spill accidents,a three-dimensional underwater oil spill model was developed using the La-grangian integral method. The model was used to simulate the pollutant trajectories under different underwater conditions,including the un-stratified stagnant, density stratified and un-straufied flowing environments, and the good agreements with the experiment data were achieved. The result showed that the model was exact and effective. A simulation example of pipeline oil spill on the seabed was presented. The study results showed that the model can be used as a powerful tool for the risk assessment, emergency response and underwater oil spill accidents.%通过对水下溢油事故特点以及污染物输移过程的分析,建立基于拉格朗日积分方法的三维水下溢油模型.数值计算了污染物在密度均匀、密度分层以及流速分层等水下环境中的扩散和输移行为,模拟结果与实验数据的吻合证明了该模型的准确性和有效性.通过渤海海底输油管道溢油事故的模拟算例研究,结果表明该模型可为水下溢油事故的风险评估、应急响应等实际应用提供理论依据和技术支持.

  16. 基于网络舆情视角的我国转基因食品安全问题分析%On China's Genetically Modified Food Safety Problems from the Network Public Opinion Perspective

    Institute of Scientific and Technical Information of China (English)

    吴林海; 吕煜昕; 吴治海

    2015-01-01

    We analyzed the genetically modified ( GM) food safety problems in China from the perspective of network public opinion. The study found that the main GM foods that internet users care the most are consistent with the GM problems existing in our country exact-ly. The result also showed that the development of GM food safety network public opinion in China in 2007-2013 experienced four stages, including the embryonic stage, the burst stage, spreading stage, and the blowout stage. We constructed the propagation path of GM food safety network public opinion, and stated briefly that the media as well as the internet users hold a distinctly negative attitude toward GM food, and the network public opinion of GM foods is far from optimistic. At last, some policy recommendations were put forward.%基于网络舆情视角分析我国的转基因食品安全问题,发现网民对转基因食品的关注与目前我国主要存在转基因问题的食品领域相吻合,将2007-2013年我国转基因食品安全网络舆情的发展分为舆情萌芽阶段、舆情突发阶段、舆情发展阶段、舆情井喷阶段等4个阶段,构建了转基因食品安全网络舆情的传播路径,认为媒体和网民对转基因食品持有明显的负面态度,我国的转基因食品安全网络舆情环境不容乐观。对此,提出了相应的政策建议。

  17. Metagenomic analysis of microbial consortium from natural crude oil that seeps into the marine ecosystem offshore Southern California

    Energy Technology Data Exchange (ETDEWEB)

    Hawley, Erik R.; Piao, Hailan; Scott, Nicole M.; Malfatti, Stephanie; Pagani, Ioanna; Huntemann, Marcel; Chen, Amy; del Rio, Tijana G.; Foster, Brian; Copeland, A.; Jansson, Janet K.; Pati, Amrita; Gilbert, Jack A.; Tringe, Susannah G.; Lorenson, Thomas D.; Hess, Matthias

    2014-01-02

    Crude oils can be major contaminants of the marine ecosystem and microorganisms play a significant role in the degradation of the main constituents of crude oil. To increase our understanding of the microbial hydrocarbon degradation process in the marine ecosystem, we collected crude oil from an active seep area located in the Santa Barbara Channel (SBC) and generated a total of about 52 Gb of raw metagenomic sequence data. The assembled data comprised ~500 Mb, representing ~1.1 million genes derived primarily from chemolithoautotrophic bacteria. Members of Oceanospirillales, a bacterial order belonging to the Deltaproteobacteria, recruited less than 2% of the assembled genes within the SBC metagenome. In contrast, the microbial community associated with the oil plume that developed in the aftermath of the Deepwater Horizon (DWH) blowout in 2010, was dominated by Oceanospirillales, which comprised more than 60% of the metagenomic data generated from the DWH oil plume. This suggests that Oceanospirillales might play a less significant role in the microbially mediated hydrocarbon conversion within the SBC seep oil compared to the DWH plume oil. We hypothesize that this difference results from the SBC oil seep being mostly anaerobic, while the DWH oil plume is aerobic. Within the Archaea, the phylum Euryarchaeota, recruited more than 95% of the assembled archaeal sequences from the SBC oil seep metagenome, with more than 50% of the sequences assigned to members of the orders Methanomicrobiales and Methanosarcinales. These orders contain organisms capable of anaerobic methanogenesis and methane oxidation (AOM) and we hypothesize that these orders and their metabolic capabilities may be fundamental to the ecology of the SBC oil seep.

  18. Kilohertz laser wakefield accelerator using near critical density plasmas and millijoule-level drive pulses

    Science.gov (United States)

    Goers, Andy

    2016-10-01

    Laser wakefield accelerators operating in the so-called bubble or blowout regime are typically driven by Joule-class femtosecond laser systems driving plasma waves in highly underdense plasmas (1017 -1019cm-3). While these accelerators are very promising for accelerating GeV scale, low emittance electron beams, the large energy requirements of the laser systems have so far limited them to repetition rates below 10 Hz. However, there are a variety of applications, such as ultrafast electron diffraction or high repetition rate gamma ray sources for materials characterization or medical radiography, which would benefit from lower energy (1-10 MeV) but higher repetition rate ( 1 kHz) sources of relativistic electrons. This talk will describe relativistic wakefield acceleration of electron bunches in the range 1-10 MeV, driven by a 1 kHz, 30 fs, 1-12 mJ laser system. Our results are made possible by the use of very high density cryogenic H2 and He gas jet targets yielding electron densities >1021cm-3 in thin 100 μm gas flows. At these high densities the critical power for relativistic self-focusing and the plasma wave phase velocity are greatly reduced, leading to pulse collapse and self-injection even with 1 mJ drive laser pulses. Applications of this source to ultrafast electron diffraction and gamma ray radiography will be discussed. This research supported by the U.S. Department of Energy, National Science Foundation, and Air Force Office of Scientific Research.

  19. Betatron x-rays from laser plasma accelerators: a new probe for warm dense matter at LCLS

    Science.gov (United States)

    Albert, Felicie

    2016-10-01

    Betatron x-ray radiation, driven by electrons from laser-wakefield acceleration, has unique properties to probe high energy density (HED) plasmas and warm dense matter. Betatron radiation is produced when relativistic electrons oscillate in the plasma wake of a laser pulse. Its properties are similar to those of synchrotron radiation, with a 1000 fold shorter pulse. This presentation will focus on the experimental challenges and results related to the development of betatron radiation for x-ray absorption spectroscopy of HED matter at large-scale laser facilities. A detailed presentation of the source mechanisms and characteristics in the blowout regime of laser-wakefield acceleration will be followed by a description of recent experiments performed at the Linac Coherent Light Source (LCLS). At LCLS, we have recently commissioned the betatron x-ray source driven by the MEC short pulse laser (1 J, 40 fs). The source is used as a probe for investigating the X-ray absorption near edge structure (XANES) spectrum at the K- or L-edge of iron and silicon oxide driven to a warm dense matter state (temperature of a few eV and solid densities). The driver is either LCLS itself or an optical laser. These experiments demonstrate the capability to study the electron-ion equilibration mechanisms in warm dense matter with sub-picosecond resolution. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344, and supported by the Laboratory Directed research and development program under tracking codes 13-LW-076, 16-ERD-041 and by the Office of Fusion Energy Sciences under SCW1476 and SCW1569.

  20. Combustion of hythane diluted with CO2

    Directory of Open Access Journals (Sweden)

    Hraiech Ibtissem

    2015-01-01

    Full Text Available With increasing concern about energy shortage and environmental protection, improving engine fuel economy and reducing exhaust emissions have become major research topics in combustion and engine development. Hythane (a blend of hydrogen H2 and natural gas NG has generated a significant interest as an alternative fuel for the future. This paper describes an experimental study of the effects of CO2 addition on the stability of a turbulent jet diffusion NG-H2 flame. The mole fraction of hydrogen (% H2 in NG-H2 mixture was varied from 0% to 50%. The equivalence ratio of the hythane/CO2/air mixture was kept at stoichiometry. The results show that the lift-off height increases with the addition of CO2 at various % H2 content in hythane. However, we observe that with 20% H2, we can obtain a stable flame diluted with 40% CO2, while for 0% H2, the flame is blown out above 20% CO2. This means that the limits of flame blowing out are pushed with the additions of H2. Moreover, the results show that for %H2 content in NG-H2 fuel up to 10%, the addition of CO2 could produce lifted flame if the % CO2 is low. At higher % CO2 dilution, flame would remain attached until blow-out. This is mainly due to the fact that the dilution leads to ejection velocities very high but reactivity of the mixture does not change so the flame tends to stretch.

  1. Developing Improved Water Velocity and Flux Estimation from AUVs - Results From Recent ASTEP Field Programs

    Science.gov (United States)

    Kinsey, J. C.; Yoerger, D. R.; Camilli, R.; German, C. R.

    2010-12-01

    Water velocity measurements are crucial to quantifying fluxes and better understanding water as a fundamental transport mechanism for marine chemical and biological processes. The importance of flux to understanding these processes makes it a crucial component of astrobiological exploration to moons possessing large bodies of water, such as Europa. Present technology allows us to obtain submerged water velocity measurements from stationary platforms; rarer are measurements from submerged vehicles which possess the ability to autonomously survey tens of kilometers over extended periods. Improving this capability would also allow us to obtain co-registered water velocity and other sensor data (e.g., mass spectrometers, temperature, oxygen, etc) and significantly enhance our ability to estimate fluxes. We report results from 4 recent expeditions in which we measured water velocities from autonomous underwater vehicles (AUVs) to help quantify flux in three different oceanographic contexts: hydrothermal vent plumes; an oil spill cruise responding to the 2010 Deepwater Horizon blowout; and two expeditions investigating naturally occurring methane seeps. On all of these cruises, we directly measured the water velocities with an acoustic Doppler current profiler (ADCP) mounted on the AUV. Vehicle motion was corrected for using bottom-lock Doppler tracks when available and, in the absence of bottom-lock, estimates of vehicle velocity based on dynamic models. In addition, on the methane seep cruises, we explored the potential of using acoustic mapping sonars, such as multi-beam and sub-bottom profiling systems, to localize plumes and indirectly quantify flux. Data obtained on these expeditions enhanced our scientific investigations and provides data for future development of algorithms for autonomously processing, identifying, and classifying water velocity and flux measurements. Such technology will be crucial in future astrobiology missions where highly constrained

  2. Fístula linfática cervical: manejo conservador Neck chylous fistula: conservative treatment

    Directory of Open Access Journals (Sweden)

    Mª J. López Otero

    2010-12-01

    Full Text Available La fístula quilosa, por daño del conducto torácico, aparece en el 1-2,5% de los pacientes sometidos a disección cervical. Las complicaciones asociadas incluyen desnutrición, compromiso inmune, formación de fístulas y necrosis cutánea con exposición carotídea, e incluso ruptura. De la literatura actual no se puede deducir ningún algoritmo de tratamiento definitivo, pero parece existir un consenso en realizar un manejo conservador de la mayoría de los casos. El manejo médico se basa en la teoría de que si se disminuye el flujo de quilo se permitirá el cierre espontáneo de la fístula, e incluye: drenaje conectado a vacío, reposo, vendaje compresivo (en discusión, intervención nutricional y uso de análogos de somatostatina. El manejo nutricional implica el uso de dietas bajas en grasa suplementadas con Triglicéridos de Cadena Media (MCT, Nutrición Enteral con TCM o Nutrición Parenteral total (NPT.Injury to the thoracic duct, leading to chyle leak, occurs in 1-2,5% of patients who undergo neck dissection. Associated complications include malnutrition, immune compromise, fistula formation and carotid blowout. No definitive treatment algorithm can be deduced from the current literature, but on last reviews, there is an agreement on the conservative management. Medical management is based on that decreasing chyle flow will allow for spontaneous closure of the chyle leak. Conservative treatment includes: closed vacuum drainage, bed-rest, nutrition modification and synthetic somatostatin analog. Nutrition modification involves a low-fat diet supplemented with medium-chain triglycerides (MCT, enteral nutrition with high percentage of MCT or parenteral nutrition.

  3. 40-year analysis of US oil spillage rates

    Energy Technology Data Exchange (ETDEWEB)

    Etkin, D.S. [Environmental Research Consulting, Cortlandt Manor, NY (United States)

    2009-07-01

    Environmentalists are concerned about the plans to open US offshore and Arctic regions for oil exploration and production. The US environmental movement gained ground after the Santa Barbara well blowout in 1969. Following the Exxon Valdez spill in 1989, the movement spurred regulatory changes and industry initiatives to prevent oil spills. The implementation of prevention-oriented regulations and voluntary industry initiatives have contributed to a considerable reduction in spillage over the past 40 years. This presentation provided average annual total petroleum industry and non-industry spillage statistics during that time frame. In this study, oil was referred to as a broadly-defined class of liquid hydrocarbon mixtures, including crude oil and liquid refined petroleum products and waste oils, but did not include BTEX compounds, petroleum chemicals or highly-volatile liquids. Spills were defined as an event in which oil is accidentally, or occasionally intentionally, released to the environment. The presentation addressed issues regarding natural seeps and spillage from oil industry activities. This included spills associated with offshore oil exploration and production activities; spills from inland production wells; spills from oil tank vessels and non-tank vessels; spills from coastal and inland pipes; spills from railroads, tanker trucks and oil refining; spills related to oil consumption; spills from coastal marine facilities; spills from gas stations and truck stops; spills from residential home heating oil tanks; and spills from motor vehicles. Legally permitted oil discharges were discussed with reference to produced water, refinery effluent discharges, and lubricants from vessels. The study showed that over the last decade, the largest source category of spillage was inland pipelines followed by EPA-regulated facilities. Changes in spillage rates between 1988 and 1997 has shown that there has been a general downward trend in US spills. 18 refs., 33

  4. Numerical model for surge and swab pressures on wells with cross-section variation

    Energy Technology Data Exchange (ETDEWEB)

    Fedevjcyk, Joao Victor; Junqueira, Silvio Luiz de Mello; Negrao, Cezar Otaviano Ribeiro [UTFPR - Federal University of Technology - Parana - Curitiba, PR (Brazil)], e-mails: silvio@utfpr.edu.br, negrao@utfpr.edu.br

    2010-07-01

    Drilling is one of the most complex steps in petroleum exploration. The process is accomplished by rotating a drill bit to compress the rock formation. During drilling, a fluid is pumped into the well to lubricate and cool down the drill bit, to clean up the well, to avoid the formation fluid influx to the well and also to stabilize the borehole walls. Fluid circulation, however, can be interrupted for maintenance reasons and the drill pipe can be moved to remove the drill bit. The downward or upward movement of the drill pipe displaces the fluid within the well causing either under pressure (swab) or over pressure (surge), respectively. If the pressure at the well bore overcomes the formation fracture pressure, a loss of circulation can take place. On the other way round, the upward movement may reduce the pressure below the pore pressure and an inflow of fluid to the well (kick) can occur. An uncontrolled kick may cause a blowout with serious damages. The transient flow induced by the axial movement of the drill pipe is responsible for the pressure changes at the well bore. Nevertheless, the well bore cross section variation may modify the pressure change within the pipe. In this paper, the effects of diameter variation of the drilling well on the surge and swab pressures are investigated. The equations that represent the phenomenon (mass and momentum conservation) are discretized by the finite volume method. Despite its non-Newtonian properties, the fluid is considered Newtonian in this first work. The drill pipe is considered closed and the flow is assumed as single-phased, one-dimensional, isothermal, laminar, compressible and transient. A sensitivity analysis of the flow parameters is carried out. The cross-section changes cause the reflection of the pressure wave, and consequently pressure oscillations. (author)

  5. Characterization of the Inner Disk around HD 141569 A from Keck/NIRC2 L-Band Vortex Coronagraphy

    Science.gov (United States)

    Mawet, Dimitri; Choquet, Élodie; Absil, Olivier; Huby, Elsa; Bottom, Michael; Serabyn, Eugene; Femenia, Bruno; Lebreton, Jérémy; Matthews, Keith; Gomez Gonzalez, Carlos A.; Wertz, Olivier; Carlomagno, Brunella; Christiaens, Valentin; Defrère, Denis; Delacroix, Christian; Forsberg, Pontus; Habraken, Serge; Jolivet, Aissa; Karlsson, Mikael; Milli, Julien; Pinte, Christophe; Piron, Pierre; Reggiani, Maddalena; Surdej, Jean; Vargas Catalan, Ernesto

    2017-01-01

    HD 141569 A is a pre-main sequence B9.5 Ve star surrounded by a prominent and complex circumstellar disk, likely still in a transition stage from protoplanetary to debris disk phase. Here, we present a new image of the third inner disk component of HD 141569 A made in the L‧ band (3.8 μm) during the commissioning of the vector vortex coronagraph that has recently been installed in the near-infrared imager and spectrograph NIRC2 behind the W.M. Keck Observatory Keck II adaptive optics system. We used reference point-spread function subtraction, which reveals the innermost disk component from the inner working distance of ≃23 au and up to ≃70 au. The spatial scale of our detection roughly corresponds to the optical and near-infrared scattered light, thermal Q, N, and 8.6 μm PAH emission reported earlier. We also see an outward progression in dust location from the L‧ band to the H band (Very Large Telescope/SPHERE image) to the visible (Hubble Space Telescope (HST)/STIS image), which is likely indicative of dust blowout. The warm disk component is nested deep inside the two outer belts imaged by HST-NICMOS in 1999 (at 406 and 245 au, respectively). We fit our new L‧-band image and spectral energy distribution of HD 141569 A with the radiative transfer code MCFOST. Our best-fit models favor pure olivine grains and are consistent with the composition of the outer belts. While our image shows a putative very faint point-like clump or source embedded in the inner disk, we did not detect any true companion within the gap between the inner disk and the first outer ring, at a sensitivity of a few Jupiter masses.

  6. A Comprehensive Dust Model Applied to the Resolved Beta Pictoris Debris Disk from Optical to Radio Wavelengths

    Science.gov (United States)

    Ballering, Nicholas P.; Su, Kate Y. L.; Rieke, George H.; Gáspár, András

    2016-06-01

    We investigate whether varying the dust composition (described by the optical constants) can solve a persistent problem in debris disk modeling—the inability to fit the thermal emission without overpredicting the scattered light. We model five images of the β Pictoris disk: two in scattered light from the Hubble Space Telescope (HST)/Space Telescope Imaging Spectrograph at 0.58 μm and HST/Wide Field Camera 3 (WFC 3) at 1.16 μm, and three in thermal emission from Spitzer/Multiband Imaging Photometer for Spitzer (MIPS) at 24 μm, Herschel/PACS at 70 μm, and Atacama Large Millimeter/submillimeter Array at 870 μm. The WFC3 and MIPS data are published here for the first time. We focus our modeling on the outer part of this disk, consisting of a parent body ring and a halo of small grains. First, we confirm that a model using astronomical silicates cannot simultaneously fit the thermal and scattered light data. Next, we use a simple generic function for the optical constants to show that varying the dust composition can improve the fit substantially. Finally, we model the dust as a mixture of the most plausible debris constituents: astronomical silicates, water ice, organic refractory material, and vacuum. We achieve a good fit to all data sets with grains composed predominantly of silicates and organics, while ice and vacuum are, at most, present in small amounts. This composition is similar to one derived from previous work on the HR 4796A disk. Our model also fits the thermal spectral energy distribution, scattered light colors, and high-resolution mid-IR data from T-ReCS for this disk. Additionally, we show that sub-blowout grains are a necessary component of the halo.

  7. Factors affecting shut-in pressure rise: kicks in offshore HPHT wells

    Energy Technology Data Exchange (ETDEWEB)

    Schilhab, L.C. [Sedco Forex, (Country unknown/Code not available); Rezmer-Cooper, I.M. [Anadril, (Country unknown/Code not available)

    1997-05-01

    Deep water and HPHT operations are two areas where the use of sophisticated simulators can enable difficult processes and procedures to be broken down into individual identifiable contributions. In the paper we discuss some of the factors that are likely to affect shut-in pressure rise in offshore drilling operations, and how a simulator can be used to answer other, less obvious questions concerning deep water well control operations. We examine the effect of gas solubility by considering a gas-kick in a deep HPHT well drilled with oil-base mud. In this case, most of the influx will be dissolved in the mud, thus removing one of the processes for increasing the wellbore pressure. In terms of s safe state to disconnect from a well in rough weather, provided that the mud yield stress negates migration of the gas-cut mud, leaving the influx in solution at the bottom of the well should not lead to increasing wellbore pressures. Significant wellbore pressure effects may also occur after closing the blowout preventers (BOP`s) on a well without an influx (or with an influx in solution), and allowing the mud to heat up. We show that in typical HPHT geometries the pressure can rise by up to 8 bar/deg C. Similar magnitudes of pressure can also increase whilst circulating trapped gas out of a BOP at the end of a well control operation. We note that these effects may also be attenuated by fluid loss and wellbore compliance for wells with significant open hole sections. Indeed, gas trapped in the BOP should be safety removed by established well control procedures. However, preliminary studies with the simulator (and confirmed by field tests in the literature) have shown that an accidental release of a small amount of gas into a deep water riser may disperse, and not cause the riser to unload. (authors) 5 refs.

  8. RESOLVED MILLIMETER-WAVELENGTH OBSERVATIONS OF DEBRIS DISKS AROUND SOLAR-TYPE STARS

    Energy Technology Data Exchange (ETDEWEB)

    Steele, Amy; Hughes, A. Meredith [Department of Astronomy, Van Vleck Observatory, Wesleyan University, 96 Foss Hill Drive, Middletown, CT, 06459 (United States); Carpenter, John [Division of Physics, Mathematics, and Astronomy, MC249-17, California Institute of Technology, Pasadena, CA 91125 (United States); Ricarte, Angelo [J. W. Gibbs Laboratory, Department of Astronomy, Yale University, 260 Whitney Avenue, New Haven, CT 06511 (United States); Andrews, Sean M.; Wilner, David J. [Harvard-Smithsonian Center for Astrophysics, MS-42, 60 Garden Street, Cambridge, MA 02138 (United States); Chiang, Eugene, E-mail: asteele@wesleyan.edu [Department of Astronomy, 501 Campbell Hall, University of California, Berkeley, CA 94720-3411 (United States)

    2016-01-01

    The presence of debris disks around young main-sequence stars hints at the existence and structure of planetary systems. Millimeter-wavelength observations probe large grains that trace the location of planetesimal belts. The Formation and Evolution of Planetary Systems Spitzer Legacy survey of nearby young solar analogues yielded a sample of five debris disk-hosting stars with millimeter flux suitable for interferometric follow-up. We present observations with the Submillimeter Array (SMA) and the Combined Array for Research in Millimeter-wave Astronomy at ∼2″ resolution that spatially resolve the debris disks around these nearby (d ∼ 50 pc) stars. Two of the five disks (HD 377, HD 8907) are spatially resolved for the first time and one (HD 104860) is resolved at millimeter wavelengths for the first time. We combine our new observations with archival SMA and Atacama Large Millimeter/Submillimeter Array data to enable a uniform analysis of the full five-object sample. We simultaneously model the broadband photometric data and resolved millimeter visibilities to constrain the dust temperatures and disk morphologies, and perform a Markov Chain Monte Carlo analysis to fit for basic structural parameters. We find that the radii and widths of the cold outer belts exhibit properties consistent with scaled-up versions of the Solar System's Kuiper Belt. All the disks exhibit characteristic grain sizes comparable to the blowout size, and all the resolved observations of emission from large dust grains are consistent with an axisymmetric dust distribution to within the uncertainties. These results are consistent with comparable studies carried out at infrared wavelengths.

  9. Failed anterior cruciate ligament reconstruction: analysis of factors leading to instability after primary surgery

    Institute of Scientific and Technical Information of China (English)

    MA Yong; AO Ying-fang; YU Jia-kuo; DAI Ling-hui; SHAO Zhen-xing

    2013-01-01

    Background Revision anterior cruciate ligament (ACL) surgery can be expected to become more common as the number of primary reconstruction keeps increasing.This study aims to investigate the factors causing instability after primary ACL reconstruction,which may provide an essential scientific base to prevent surgical failure.Methods One hundred and ten revision ACL surgeries were performed at our institute between November 2001 and July 2012.There were 74 men and 36 women,and the mean age at the time of revision was 27.6 years (range 16-56 years).The factors leading to instability after primary ACL reconstruction were retrospectively reviewed.Results Fifty-one knees failed because of bone tunnel malposition,with too anterior femoral tunnels (20 knees),posterior wall blowout (1 knee),vertical femoral tunnels (7 knees),too posterior tibial tunnels (12 knees),and too anterior tibial tunnels (10 knees).There was another knee performed with open surgery,where the femoral tunnel was drilled through the medial condyle and the tibial tunnel was too anterior.Five knees were found with malposition of the fixation.One knee with allograft was suspected of rejection and a second surgery had been made to take out the graft.Three knees met recurrent instability after postoperative infection.The other factors included traumatic (48 knees) and unidentified (12 knees).Conclusion Technical errors were the main factors leading to instability after primary ACL reconstructions,while attention should also be paid to the risk factors of re-injury and failure of graft incorporation.

  10. Late Pleistocene wind-action and periglacial phenomena in sandy terrain, New Jersey Pine Barrens

    Science.gov (United States)

    Demitroff, M. N.; Cicali, M.

    2013-12-01

    Examination of the Pinelands past permafrost environment will add insight to the relatively scant record of the Mid-Atlantic region's periglacial realm, a place where cold, dry, and windy conditions predominated during the recent glacials. This area is especially important to the understanding of mid-latitudinal climate change dynamics in ice-marginal locations - areas greatly affected by diurnal, seasonal, and long-term climate perturbations. We provide examples from a well-preserved pine-forest reserve on coastal plain (39-40° N) that experienced multiple episodes of permafrost aggradation and degradation during the last 200,000 years. While a large number of publications describe an array of relict periglacial phenomena from low-relief areas in Europe's sand belt (UK-Russia), much less is known about the ice-marginal continental mass of North America. High-resolution geodetically corrected airborne LiDAR data enhanced with alternate views through the use of early aerial photo imagery is provided and analyzed to produce bare earth landforms revealing perspective eolian structures. Fieldwork at sand mine operations adjacent to relict dune fields offered sectional views of what lies beneath wind-affected land surfaces. This region was found to have been sparsely vegetated land akin to polar barrens during cold epochs. Coversand is the dominant eolian depositional form, with parabolic dune fields scattered along downwind banks of larger watercourses. Eolian systems interact with the local paleohydrology. Wind-erosional features include ventifacts, blowouts, and, on occasion, yardangs. Sand-filled frost cracks attest to aridity during permafrost aggradation and deep-seasonal frost. These periglacial macrostructures often deform into furrows and sediment-filled pots upon permafrost degradation. The sites are easily accessible providing ample opportunities for frozen ground and climate change studies.

  11. Health Impact Assessment of an oil drilling project in California

    Directory of Open Access Journals (Sweden)

    Lindsay C. McCallum

    2016-04-01

    Full Text Available Objectives: The Health Impact Assessment (HIA was conducted to evaluate the potential community health implications of a proposed oil drilling and production project in Hermosa Beach, California. The HIA considered 17 determinants of health that fell under 6 major categories (i.e., air quality, water and soil quality, upset conditions, noise and light emissions, traffic, and community livability. Material and Methods: This paper attempts to address some of the gaps within the HIA practice by presenting the methodological approach and results of this transparent, comprehensive HIA; specifically, the evaluation matrix and decision-making framework that have been developed for this HIA and form the basis of the evaluation and allow for a clear conclusion to be reached in respect of any given health determinant (i.e., positive, negative, neutral. Results: There is a number of aspects of the project that may positively influence health (e.g., increased education funding, ability to enhance green space, and at the same time there have been potential negative effects identified (e.g., odor, blowouts, property values. Except for upset conditions, the negative health outcomes have been largely nuisance-related (e.g., odor, aesthetics without irreversible health impacts. The majority of the health determinants, that had been examined, have revealed that the project would have no substantial effect on the health of the community. Conclusions: Using the newly developed methodology and based on established mitigation measures and additional recommendations provided in the HIA, the authors have concluded that the project will have no substantial effect on community health. This approach and methodology will assist practitioners, stakeholders and decision-makers in advancing the HIA as a useful, reproducible, and informative tool.

  12. Biodiversity impact of the aeolian periglacial geomorphologic evolution of the Fontainebleau Massif (France)

    Science.gov (United States)

    Thiry, M.; Liron, M. N.

    2009-04-01

    Landscape features The geomorphology of the Fontainebleau Massif is noteworthy for its spectacular narrow ridges, up to 10 km long and 0.5 km wide, armored by tightly cemented sandstone lenses and which overhang sandy depressions of about 50m. Denudation of the sandstone pans lead to a highly contrasted landscape, with sandstone ridges ("platières") towering sandy depressions ("vallées") and limestone plateaus ("monts"). This forms the geological frame of the spectacular sceneries of the Fontainebleau Massif (Thiry & Liron, 2007). Nevertheless, there is little know about the erosive processes that have built-up these landscapes. Periglacial processes, and among them aeolian ones, appear significant in the development of the Fontainebleau Massif physiography. The periglacial aeolian geomorphology Dunes and dune fields are known since long and cover about 15% to 25% of the Fontainebleau Massif. The aeolian dunes developed as well on the higher parts of the landscape, as well as in the lower parts of the landscape. The dunes are especially well developed in the whole eastern part of the massif, whereas the western part of the massif is almost devoid of dunes. Nevertheless, detailed mapping shows that dunes can locally be found in the western district, they are of limited extension, restricted to the east facing backslope of outliers. Loamy-sand covers the limestone plateaus of the "monts". The loam cover is of variable thickness: schematically thicker in the central part of the plateaus, where it my reach 3 m; elsewhere it may thin down to 0,20-0,30 m, especially at the plateau edges. Blowout hollows are "negative" morphologies from where the sand has been withdrawed. Often these blowouts are decametric sized and well-delimited structures. Others, more complex structures, are made up of several elongated hectometric hollows relaying each other from and which outline deflation corridor more than 1 km long. A characteristic feature of these blowout hollows is the

  13. Quantifying Methane Flux from a Prominent Seafloor Crater with Water Column Imagery Filtering and Bubble Quantification Techniques

    Science.gov (United States)

    Mitchell, G. A.; Gharib, J. J.; Doolittle, D. F.

    2015-12-01

    Methane gas flux from the seafloor to atmosphere is an important variable for global carbon cycle and climate models, yet is poorly constrained. Methodologies used to estimate seafloor gas flux commonly employ a combination of acoustic and optical techniques. These techniques often use hull-mounted multibeam echosounders (MBES) to quickly ensonify large volumes of the water column for acoustic backscatter anomalies indicative of gas bubble plumes. Detection of these water column anomalies with a MBES provides information on the lateral distribution of the plumes, the midwater dimensions of the plumes, and their positions on the seafloor. Seafloor plume locations are targeted for visual investigations using a remotely operated vehicle (ROV) to determine bubble emission rates, venting behaviors, bubble sizes, and ascent velocities. Once these variables are measured in-situ, an extrapolation of gas flux is made over the survey area using the number of remotely-mapped flares. This methodology was applied to a geophysical survey conducted in 2013 over a large seafloor crater that developed in response to an oil well blowout in 1983 offshore Papua New Guinea. The site was investigated by multibeam and sidescan mapping, sub-bottom profiling, 2-D high-resolution multi-channel seismic reflection, and ROV video and coring operations. Numerous water column plumes were detected in the data suggesting vigorously active vents within and near the seafloor crater (Figure 1). This study uses dual-frequency MBES datasets (Reson 7125, 200/400 kHz) and ROV video imagery of the active hydrocarbon seeps to estimate total gas flux from the crater. Plumes of bubbles were extracted from the water column data using threshold filtering techniques. Analysis of video images of the seep emission sites within the crater provided estimates on bubble size, expulsion frequency, and ascent velocity. The average gas flux characteristics made from ROV video observations is extrapolated over the number

  14. Effects of Combustion-Induced Vortex Breakdown on Flashback Limits of Syngas-Fueled Gas Turbine Combustors

    Energy Technology Data Exchange (ETDEWEB)

    Ahsan Choudhuri

    2011-03-31

    Turbine combustors of advanced power systems have goals to achieve very low pollutants emissions, fuel variability, and fuel flexibility. Future generation gas turbine combustors should tolerate fuel compositions ranging from natural gas to a broad range of syngas without sacrificing operational advantages and low emission characteristics. Additionally, current designs of advanced turbine combustors use various degrees of swirl and lean premixing for stabilizing flames and controlling high temperature NOx formation zones. However, issues of fuel variability and NOx control through premixing also bring a number of concerns, especially combustor flashback and flame blowout. Flashback is a combustion condition at which the flame propagates upstream against the gas stream into the burner tube. Flashback is a critical issue for premixed combustor designs, because it not only causes serious hardware damages but also increases pollutant emissions. In swirl stabilized lean premixed turbine combustors onset of flashback may occur due to (i) boundary layer flame propagation (critical velocity gradient), (ii) turbulent flame propagation in core flow, (iii) combustion instabilities, and (iv) upstream flame propagation induced by combustion induced vortex breakdown (CIVB). Flashback due to first two foregoing mechanisms is a topic of classical interest and has been studied extensively. Generally, analytical theories and experimental determinations of laminar and turbulent burning velocities model these mechanisms with sufficient precision for design usages. However, the swirling flow complicates the flashback processes in premixed combustions and the first two mechanisms inadequately describe the flashback propensity of most practical combustor designs. The presence of hydrogen in syngas significantly increases the potential for flashback. Due to high laminar burning velocity and low lean flammability limit, hydrogen tends to shift the combustor operating conditions towards

  15. Characteristics and hydrodynamic interpretation of storm-emplaced cliff-top boulder ridges on Inishmore, Aran Islands, Ireland

    Science.gov (United States)

    Zentner, D. B.; Cox, R.

    2008-12-01

    Dramatic boulder ridges are widespread on cliff-top platforms of Ireland's Aran Islands, emplaced by storm waves at elevations up to 50 m. In places the ridges have overridden 19th-century field walls, and recent movement of large blocks is attested to by modern debris--including nylon ropes, aerosol cans, and plastic bottles--pinned under megaclasts of up to 40 tons. Large waves are common off Ireland's west coast, as revealed by the short records available from recently-deployed buoy systems. The Irish Marine Weather Buoy Network measured wave heights (≥10 m on 29 days between 2001 and 2007, and waves up to 18 m high were recorded in December 2007. Blocks quarried by such waves from the upper few m of the cliffs are transported inland to form semi-continuous boulder ridges parallel to the coastline, which therefore offer a record of hydrodynamics during high-energy wave events. On Inishmore, boulder ridges occur at elevations up to 28 m, separated from the cliff edge by wave-scoured platforms 1-70 m wide. The ridges consist of imbricated, highly angular slabs, ranging from small gravel to 5 m megaclasts. They are 1-4.6 m high, 10-48 m wide (Ripple Index 5-17), and strongly asymmetric, with steep narrow stoss faces (10- 35°), and long gentle lee slopes (<14°). With increasing cliff height, ridges are smaller, narrower, made of smaller blocks, and sit closer to the edge; but ridges 20 m wide and 2 m high, with half-ton clasts, occur as high as 28 m OD. The deposits are moderately to well sorted, predominantly unimodal, and fine skewed. Median clast size ranges from fine to coarse boulders (0.5-2 m). Clasts show strong seaward imbrication on both stoss and lee sides (dipping up to 85° with average 25°). "Blowout" features on the lee sides, with boulders imbricated radially around central depressions of 1-2 m diameter, suggest turbulent flow separation, as does the common occurrence of 1-3 smaller secondary ridges landward of the main crest. The uniformity of

  16. Flexible, Mechanically Durable Aerogel Composites for Oil Capture and Recovery.

    Science.gov (United States)

    Karatum, Osman; Steiner, Stephen A; Griffin, Justin S; Shi, Wenbo; Plata, Desiree L

    2016-01-13

    More than 30 years separate the two largest oil spills in North American history (the Ixtoc I and Macondo well blowouts), yet the responses to both disasters were nearly identical in spite of advanced material innovation during the same time period. Novel, mechanically durable sorbents could enable (a) sorbent use in the open ocean, (b) automated deployment to minimize workforce exposure to toxic chemicals, and (c) mechanical recovery of spilled oils. Here, we explore the use of two mechanically durable, low-density (0.1-0.2 g cm(-3)), highly porous (85-99% porosity), hydrophobic (water contact angles >120°), flexible aerogel composite blankets as sorbent materials for automated oil capture and recovery: Cabot Thermal Wrap (TW) and Aspen Aerogels Spaceloft (SL). Uptake of crude oils (Iraq and Sweet Bryan Mound oils) was 8.0 ± 0.1 and 6.5 ± 0.3 g g(-1) for SL and 14.0 ± 0.1 and 12.2 ± 0.1 g g(-1) for TW, respectively, nearly twice as high as similar polyurethane- and polypropylene-based devices. Compound-specific uptake experiments and discrimination against water uptake suggested an adsorption-influenced sorption mechanism. Consistent with that mechanism, chemical extraction oil recoveries were 95 ± 2 (SL) and 90 ± 2% (TW), but this is an undesirable extraction route in decentralized oil cleanup efforts. In contrast, mechanical extraction routes are favorable, and a modest compression force (38 N) yielded 44.7 ± 0.5% initially to 42.0 ± 0.4% over 10 reuse cycles for SL and initially 55.0 ± 0.1% for TW, degrading to 30.0 ± 0.2% by the end of 10 cycles. The mechanical integrity of SL deteriorated substantially (800 ± 200 to 80 ± 30 kPa), whereas TW was more robust (380 ± 80 to 700 ± 100 kPa) over 10 uptake-and-compression extraction cycles.

  17. HST images of FeLoBAL quasars: Testing quasar-galaxy evolution models

    Science.gov (United States)

    Herbst, Hanna; Hamann, Fred; Villforth, Carolin; Caselli, Paola; Koekemoer, Anton M.; Veilleux, Sylvain

    2016-01-01

    We present preliminary results from an HST imaging study of FeLoBAL quasars, which have extremely low-ionization Broad Absorption Line (BAL) outflows and might be a young quasar population based on their red colors, large far-IR luminosities (suggesting high star formation rates), and powerful outflows. Some models of quasar - host galaxy evolution propose a triggering event, such as a merger, to fuel both a burst of star formation and the quasar/AGN activity. These models suggest young quasars are initially obscured inside the dusty starburst until a "blowout" phase, driven by the starburst or quasar outflows like FeLoBALs, ends the star formation and reveals the visibly luminous quasar. Despite the popularity of this evolution scheme, there is little observational evidence to support the role of mergers in triggering AGN or the youth of dust-reddened quasars (such as FeLoBALs) compared to normal blue quasars.Our Cycle 22 HST program is designed to test the youth of FeLoBAL quasars and the connection of FeLoBALs to mergers. We obtain WFC3/IR F160W images of 10 FeLoBAL quasars at redshift z~0.9 (covering ~8500A in the quasar rest frame). We will compare the host galaxy morphologies and merger signatures of FeLoBALs with normal blue quasars (which are older according to the evolution model) and non-AGN galaxies matched in redshift and stellar mass. If FeLoBAL quasars are indeed in a young evolutionary state, close in time to the initial merging event, they should have stronger merger features compared to blue quasars and non-AGN galaxies. Preliminary results suggest that this is not the case - FeLoBAL quasars appear to reside in faint, compact hosts with weak or absent merger signatures. We discuss the implications of these results for galaxy evolution models and other studies of dust-reddened quasar populations.

  18. Sensitivity of the deep-sea amphipod Eurythenes gryllus to chemically dispersed oil.

    Science.gov (United States)

    Olsen, Gro Harlaug; Coquillé, Nathalie; Le Floch, Stephane; Geraudie, Perrine; Dussauze, Matthieu; Lemaire, Philippe; Camus, Lionel

    2016-04-01

    In the context of an oil spill accident and the following oil spill response, much attention is given to the use of dispersants. Dispersants are used to disperse an oil slick from the sea surface into the water column generating a cloud of dispersed oil droplets. The main consequence is an increasing of the sea water-oil interface which induces an increase of the oil biodegradation. Hence, the use of dispersants can be effective in preventing oiling of sensitive coastal environments. Also, in case of an oil blowout from the seabed, subsea injection of dispersants may offer some benefits compared to containment and recovery of the oil or in situ burning operation at the sea surface. However, biological effects of dispersed oil are poorly understood for deep-sea species. Most effects studies on dispersed oil and also other oil-related compounds have been focusing on more shallow water species. This is the first approach to assess the sensitivity of a macro-benthic deep-sea organism to dispersed oil. This paper describes a toxicity test which was performed on the macro-benthic deep-sea amphipod (Eurythenes gryllus) to determine the concentration causing lethality to 50% of test individuals (LC50) after an exposure to dispersed Brut Arabian Light (BAL) oil. The LC50 (24 h) was 101 and 24 mg L(-1) after 72 h and 12 mg L(-1) at 96 h. Based on EPA scale of toxicity categories to aquatic organisms, an LC50 (96 h) of 12 mg L(-1) indicates that the dispersed oil was slightly to moderately toxic to E. gryllus. As an attempt to compare our results to others, a literature study was performed. Due to limited amount of data available for dispersed oil and amphipods, information on other crustacean species and other oil-related compounds was also collected. Only one study on dispersed oil and amphipods was found, the LC50 value in this study was similar to the LC50 value of E. gryllus in our study. Since toxicity data are important input to risk assessment and net environmental

  19. Discovery and Description of Extinct Asphalt Volcanoes Along the Southern California Margin

    Science.gov (United States)

    Valentine, D. L.; Reddy, C.; Ventura, G. T.; Nelson, R. K.

    2007-12-01

    Asphalt volcanism is increasingly being recognized as an important process at cold seeps, linking ancient subsurface carbon reservoirs with more rapid biogeochemical processes at the surface. Here we describe two extinct asphalt volcanoes discovered off the coast of Santa Barbara, CA, using the DSV Alvin during the July 2007 SEEPS (Studies on the Ecology and Evolution of Petroleum Seeps) cruise. These structures are located approximately 10 kilometers offshore and 2 kilometers apart from each other, at a water depth of 150 to 200 meters. The volcanoes occur as asphalt mounds closely associated with sediment-laden depressions, suggesting extrusion of liquid petroleum coupled with localized subsidence or gas blowout. The volcanoes range from 10 to 30 meters in height off the sea floor and may extend below the present level of sediment cover. No active seepage was observed during approximately 10 hours of visual and video surveys from the DSV Alvin, but the volcanoes appear to serve as an oasis for benthic life when compared to the surrounding sediment. Four asphalt samples were collected throughout each site during these surveys and all show remarkable similarity in their structure and chemical composition. Organic carbon comprises 50 percent of the mass for each sample, with sulfur, hydrogen and nitrogen comprising another 10 percent in aggregate. Inclusions of fine-grained sediment and microfossils comprise much of the residual mass and are being used in an attempt to determine the timing of the eruptive events. Each sample was analyzed for the stable isotope composition of carbon, nitrogen and sulfur, and results are consistent with a petroleum source from the Miocene-age Monterey Formation. Analysis of biomarkers using comprehensive two-dimensional gas chromatography yields a suite of hopanes and steranes also consistent with petroleum from the Monterey Formation, but with anomalously high concentrations of bisnorhopane. To our knowledge, this is the first report

  20. Fuel Flexible Combustion Systems for High-Efficiency Utilization of Opportunity Fuels in Gas Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Venkatesan, Krishna

    2011-11-30

    The purpose of this program was to develop low-emissions, efficient fuel-flexible combustion technology which enables operation of a given gas turbine on a wider range of opportunity fuels that lie outside of current natural gas-centered fuel specifications. The program encompasses a selection of important, representative fuels of opportunity for gas turbines with widely varying fundamental properties of combustion. The research program covers conceptual and detailed combustor design, fabrication, and testing of retrofitable and/or novel fuel-flexible gas turbine combustor hardware, specifically advanced fuel nozzle technology, at full-scale gas turbine combustor conditions. This project was performed over the period of October 2008 through September 2011 under Cooperative Agreement DE-FC26-08NT05868 for the U.S. Department of Energy/National Energy Technology Laboratory (USDOE/NETL) entitled "Fuel Flexible Combustion Systems for High-Efficiency Utilization of Opportunity Fuels in Gas Turbines". The overall objective of this program was met with great success. GE was able to successfully demonstrate the operability of two fuel-flexible combustion nozzles over a wide range of opportunity fuels at heavy-duty gas turbine conditions while meeting emissions goals. The GE MS6000B ("6B") gas turbine engine was chosen as the target platform for new fuel-flexible premixer development. Comprehensive conceptual design and analysis of new fuel-flexible premixing nozzles were undertaken. Gas turbine cycle models and detailed flow network models of the combustor provide the premixer conditions (temperature, pressure, pressure drops, velocities, and air flow splits) and illustrate the impact of widely varying fuel flow rates on the combustor. Detailed chemical kinetic mechanisms were employed to compare some fundamental combustion characteristics of the target fuels, including flame speeds and lean blow-out behavior. Perfectly premixed combustion experiments were conducted to

  1. RNA-Seq reveals complex genetic response to deepwater horizon oil release in Fundulus grandis

    Directory of Open Access Journals (Sweden)

    Garcia Tzintzuni I

    2012-09-01

    Full Text Available Abstract Background The release of oil resulting from the blowout of the Deepwater Horizon (DH drilling platform was one of the largest in history discharging more than 189 million gallons of oil and subject to widespread application of oil dispersants. This event impacted a wide range of ecological habitats with a complex mix of pollutants whose biological impact is still not yet fully understood. To better understand the effects on a vertebrate genome, we studied gene expression in the salt marsh minnow Fundulus grandis, which is local to the northern coast of the Gulf of Mexico and is a sister species of the ecotoxicological model Fundulus heteroclitus. To assess genomic changes, we quantified mRNA expression using high throughput sequencing technologies (RNA-Seq in F. grandis populations in the marshes and estuaries impacted by DH oil release. This application of RNA-Seq to a non-model, wild, and ecologically significant organism is an important evaluation of the technology to quickly assess similar events in the future. Results Our de novo assembly of RNA-Seq data produced a large set of sequences which included many duplicates and fragments. In many cases several of these could be associated with a common reference sequence using blast to query a reference database. This reduced the set of significant genes to 1,070 down-regulated and 1,251 up-regulated genes. These genes indicate a broad and complex genomic response to DH oil exposure including the expected AHR-mediated response and CYP genes. In addition a response to hypoxic conditions and an immune response are also indicated. Several genes in the choriogenin family were down-regulated in the exposed group; a response that is consistent with AH exposure. These analyses are in agreement with oligonucleotide-based microarray analyses, and describe only a subset of significant genes with aberrant regulation in the exposed set. Conclusion RNA-Seq may be successfully applied to feral and

  2. Disk Radii and Grain Sizes in Herschel-resolved Debris Disks

    Science.gov (United States)

    Pawellek, Nicole; Krivov, Alexander V.; Marshall, Jonathan P.; Montesinos, Benjamin; Ábrahám, Péter; Moór, Attila; Bryden, Geoffrey; Eiroa, Carlos

    2014-09-01

    The radii of debris disks and the sizes of their dust grains are important tracers of the planetesimal formation mechanisms and physical processes operating in these systems. Here we use a representative sample of 34 debris disks resolved in various Herschel Space Observatory (Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA) programs to constrain the disk radii and the size distribution of their dust. While we modeled disks with both warm and cold components, and identified warm inner disks around about two-thirds of the stars, we focus our analysis only on the cold outer disks, i.e., Kuiper-belt analogs. We derive the disk radii from the resolved images and find a large dispersion for host stars of any spectral class, but no significant trend with the stellar luminosity. This argues against ice lines as a dominant player in setting the debris disk sizes, since the ice line location varies with the luminosity of the central star. Fixing the disk radii to those inferred from the resolved images, we model the spectral energy distribution to determine the dust temperature and the grain size distribution for each target. While the dust temperature systematically increases toward earlier spectral types, the ratio of the dust temperature to the blackbody temperature at the disk radius decreases with the stellar luminosity. This is explained by a clear trend of typical sizes increasing toward more luminous stars. The typical grain sizes are compared to the radiation pressure blowout limit s blow that is proportional to the stellar luminosity-to-mass ratio and thus also increases toward earlier spectral classes. The grain sizes in the disks of G- to A-stars are inferred to be several times s blow at all stellar luminosities, in agreement with collisional models of debris disks. The sizes, measured in the units of s blow, appear to decrease with the luminosity

  3. HERSCHEL's ''COLD DEBRIS DISKS'': BACKGROUND GALAXIES OR QUIESCENT RIMS OF PLANETARY SYSTEMS?

    Energy Technology Data Exchange (ETDEWEB)

    Krivov, A. V.; Loehne, T.; Mutschke, H.; Neuhaeuser, R. [Astrophysikalisches Institut und Universitaetssternwarte, Friedrich-Schiller-Universitaet Jena, Schillergaesschen 2-3, D-07745 Jena (Germany); Eiroa, C.; Marshall, J. P.; Mustill, A. J. [Departamento de Fisica Teorica, Facultad de Ciencias, Universidad Autonoma de Madrid, Cantoblanco, E-28049 Madrid (Spain); Montesinos, B. [Departamento de Astrofisica, Centro de Astrobiologia (CAB, CSIC-INTA), ESAC Campus, P.O. Box 78, E-28691 Villanueva de la Canada, Madrid (Spain); Del Burgo, C. [Instituto Nacional de Astrofisica, Optica y Electronica (INAOE), Apartado Postal 51 y 216, 72000 Puebla, Pue. (Mexico); Absil, O. [Institut d' Astrophysique et de Geophysique, Universite de Liege, Allee du 6 Aout 17, B-4000 Liege (Belgium); Ardila, D. [NASA Herschel Science Center, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Augereau, J.-C.; Ertel, S.; Lebreton, J. [UJF-Grenoble 1/CNRS-INSU, Institut de Planetologie et d' Astrophysique de Grenoble (IPAG), UMR 5274, F-38041 Grenoble (France); Bayo, A. [European Southern Observatory, Alonso de Cordova 3107, Vitacura, Santiago (Chile); Bryden, G. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Danchi, W. [NASA Goddard Space Flight Center, Exoplanets and Stellar Astrophysics, Code 667, Greenbelt, MD 20771 (United States); Liseau, R. [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, SE-43992, Onsala (Sweden); Mora, A. [ESA-ESAC Gaia SOC, P.O. Box 78, E-28691 Villanueva de la Canada, Madrid (Spain); Pilbratt, G. L., E-mail: krivov@astro.uni-jena.de [ESA Astrophysics and Fundamental Physics Missions Division, ESTEC/SRE-SA, Keplerlaan 1, 2201 AZ Noordwijk (Netherlands); and others

    2013-07-20

    Infrared excesses associated with debris disk host stars detected so far peak at wavelengths around {approx}100 {mu}m or shorter. However, 6 out of 31 excess sources studied in the Herschel Open Time Key Programme, DUNES, have been seen to show significant-and in some cases extended-excess emission at 160 {mu}m, which is larger than the 100 {mu}m excess. This excess emission has been attributed to circumstellar dust and has been suggested to stem from debris disks colder than those known previously. Since the excess emission of the cold disk candidates is extremely weak, challenging even the unrivaled sensitivity of Herschel, it is prudent to carefully consider whether some or even all of them may represent unrelated galactic or extragalactic emission, or even instrumental noise. We re-address these issues using several distinct methods and conclude that it is highly unlikely that none of the candidates represents a true circumstellar disk. For true disks, both the dust temperatures inferred from the spectral energy distributions and the disk radii estimated from the images suggest that the dust is nearly as cold as a blackbody. This requires the grains to be larger than {approx}100 {mu}m, even if they are rich in ices or are composed of any other material with a low absorption in the visible. The dearth of small grains is puzzling, since collisional models of debris disks predict that grains of all sizes down to several times the radiation pressure blowout limit should be present. We explore several conceivable scenarios: transport-dominated disks, disks of low dynamical excitation, and disks of unstirred primordial macroscopic grains. Our qualitative analysis and collisional simulations rule out the first two of these scenarios, but show the feasibility of the third one. We show that such disks can indeed survive for gigayears, largely preserving the primordial size distribution. They should be composed of macroscopic solids larger than millimeters, but smaller

  4. 'Orbital volume restoration rate after orbital fracture'; a CT-based orbital volume measurement for evaluation of orbital wall reconstructive effect.

    Science.gov (United States)

    Wi, J M; Sung, K H; Chi, M

    2017-01-13

    PurposeTo evaluate the effect of orbital reconstruction and factors related to the effect of orbital reconstruction by assessing of orbital volume using orbital computed tomography (CT) in cases of orbital wall fracture.MethodsIn this retrospective study, 68 patients with isolated blowout fractures were evaluated. The volumes of orbits and herniated orbital tissues were determined by CT scans using a three-dimensional reconstruction technique (the Eclipse Treatment Planning System). Orbital CT was performed preoperatively, immediately after surgery, and at final follow ups (minimum of 6 months). We evaluated the reconstructive effect of surgery making a new formula, 'orbital volume reconstruction rate' from orbital volume differences between fractured and contralateral orbits before surgery, immediately after surgery, and at final follow up.ResultsMean volume of fractured orbits before surgery was 23.01±2.60 cm(3) and that of contralateral orbits was 21.31±2.50 cm(3) (P=0.005). Mean volume of the fractured orbits immediately after surgery was 21.29±2.42 cm(3), and that of the contralateral orbits was 21.33±2.52 cm(3) (P=0.921). Mean volume of fractured orbits at final follow up was 21.50±2.44 cm(3), and that of contralateral orbits was 21.32±2.50 cm(3) (P=0.668). The mean orbital volume reconstruction rate was 100.47% immediately after surgery and 99.17% at final follow up. No significant difference in orbital volume reconstruction rate was observed with respect to fracture site or orbital implant type. Patients that underwent operation within 14 days of trauma had a better reconstruction rate at final follow up than patients who underwent operation over 14 days after trauma (P=0.039).ConclusionComputer-based measurements of orbital fracture volume can be used to evaluate the reconstructive effect of orbital implants and provide useful quantitative information. Significant reduction of orbital volume is observed immediately after orbital wall

  5. Disk radii and grain sizes in Herschel-resolved debris disks

    Energy Technology Data Exchange (ETDEWEB)

    Pawellek, Nicole; Krivov, Alexander V. [Astrophysikalisches Institut und Universitätssternwarte, Friedrich-Schiller-Universität Jena, Schillergäßchen 2-3, 07745 Jena (Germany); Marshall, Jonathan P. [School of Physics, University of New South Wales, Sydney NSW 2052 (Australia); Montesinos, Benjamin [Departmento de Astrofísica, Centro de Astrobiología (CAB, CSIC-INTA), ESAC Campus, P.O. Box 78, E-28691 Villanueva de la Cañada, Madrid (Spain); Ábrahám, Péter; Moór, Attila [Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, P.O. Box 67, H-1525 Budapest (Hungary); Bryden, Geoffrey [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Eiroa, Carlos [Departamento de Física Teórica, Facultad de Ciencias, Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid (Spain)

    2014-09-01

    The radii of debris disks and the sizes of their dust grains are important tracers of the planetesimal formation mechanisms and physical processes operating in these systems. Here we use a representative sample of 34 debris disks resolved in various Herschel Space Observatory (Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA) programs to constrain the disk radii and the size distribution of their dust. While we modeled disks with both warm and cold components, and identified warm inner disks around about two-thirds of the stars, we focus our analysis only on the cold outer disks, i.e., Kuiper-belt analogs. We derive the disk radii from the resolved images and find a large dispersion for host stars of any spectral class, but no significant trend with the stellar luminosity. This argues against ice lines as a dominant player in setting the debris disk sizes, since the ice line location varies with the luminosity of the central star. Fixing the disk radii to those inferred from the resolved images, we model the spectral energy distribution to determine the dust temperature and the grain size distribution for each target. While the dust temperature systematically increases toward earlier spectral types, the ratio of the dust temperature to the blackbody temperature at the disk radius decreases with the stellar luminosity. This is explained by a clear trend of typical sizes increasing toward more luminous stars. The typical grain sizes are compared to the radiation pressure blowout limit s {sub blow} that is proportional to the stellar luminosity-to-mass ratio and thus also increases toward earlier spectral classes. The grain sizes in the disks of G- to A-stars are inferred to be several times s {sub blow} at all stellar luminosities, in agreement with collisional models of debris disks. The sizes, measured in the units of s {sub blow}, appear to decrease

  6. The lamina papyracea bust fracture reduction under nasal endoscope HE%眶内壁爆裂骨折的鼻内镜下手术修复

    Institute of Scientific and Technical Information of China (English)

    何峰云; 张会娟; 赵娜

    2013-01-01

    目的:探讨鼻内镜下眼眶内壁爆裂性骨折手术修复的方法及临床疗效。方法:对19例伴有眼球内陷、眼球运动障碍、复视等症状、眼眶CT扫描显示眶内壁击出性骨折的患者,在确定骨折程度及范围后,于局麻加强化麻醉下行鼻内镜下取Messcolinger入路行筛窦眶纸板骨折修复术,分析其疗效。结果:术后鼻内镜下随诊6~12月,所有患者愈后理想,均达到治愈标准,无明显眼球凹陷及复视。结论:鼻内镜下经筛窦入路行眶内壁爆裂骨折修复具有创伤小、疗效稳定、手术时间短而且面部不留疤痕等特点,是一种有效的手术方法。%Objective:To evaluate the methods and clinical efficacy of the lamina papyracea bust fracture reduction under nasal endoscope. Methods:Al 19 cases had enophthalmos, eye movement disorders,and diplopia. The orbital CT scan of these cases show the medial orbital wal blow-out fracture clearly. The degree and range of the lamina papyracea displacement was measured on CT films. The reduction under nasalendoscope was performed with local and topical anesthesia. We selected the Meeserklinger 's route of entry,and then analyze the efficacy.Result: With 6~12 moths fol ow up, al patients were cured. The endophthalmos and diplopia disappeared in al cases.Conclusion:The The lamina papyracea bust fracture reduction under nasal endoscope has many advantages such as trauma, efficacy and stability, shorter operative time and no facial scar.It is an effective surgical methods.

  7. From the Relationship between "Morality" and "Power"to See Today's Issue of Official Corruption%从“德”与“力”的关系看当今官员腐败问题

    Institute of Scientific and Technical Information of China (English)

    汪小进

    2014-01-01

    十八大之后,腐败案件频频曝光,查处力度之大,涉案领域之广,涉及官员人数之多,这种“井喷式”的反腐治腐成果让普通民众拍手称快。但在民众口诛笔伐之时,当前官员的权力、能力与道德的关系更值得深思。文章从当今社会道德体系局部失范、权力意识极度膨胀的现状引发出关于“德”与“力”关系的思考,指出以“德”与“力”为着眼点,加强当代公务员乃至普通民众的思想道德教育,并探寻政府反腐倡廉建设,重塑官员人民公仆形象的有效途径。%After the 18th CPC National Congress, corruption cases are frequently exposed to people and the investi-gation and punishment is vast, involving more and more areas and officials. This blowout type of anti-corruption outcomes make the ordinary people clap and cheer. However, when opposition exists both in speech and in writing, the relationship between the power and morality of the current officials is more worth pondering. The article is based on the current situation of local anomie of ethical system and extreme swelling of the power consciousness in today' s society, which cause people to reflect on the relationship between morality and power. The author is with the "morality" and"power" as the focus to strengthen the civil service and the general contemporary people's ideological and moral education and explore the effective way for government anti-corruption and reshape the image of officials of public servants.

  8. Selection of methods and parameters for forced weakening of roofing in stoping faces

    Energy Technology Data Exchange (ETDEWEB)

    Bekbulatov, A.K.

    1982-01-01

    The use of the method of advanced shooting on mines of different basins of the country indicated the need to generalize results of work for forced weakening of the roofing on mines in the sector in order to create ''Instructions For Selecting the Methods and Parameters of Forced Weakening of Roofing in the Stoping Faces'' with the participation of the basin scientific research institutes under the leadership of the VNIMI. The main method of weakening which has been introduced in the Karaganda basin is frontal shooting with the use of torpedo-charges. Shooting of the roofing in order reduce the intensity of the primary settling of the main roofing is done in parallel and perpendicular plans. With the parallel plan, the wells are drilled out from the adjoining roadways parallel to the stoping face, and with perpendicular plan, from the assembly chamber perpendicular to the stoping face. In order to reduce the intensity of secondary settling of the main roofing, the parallel or parallel-inclined method is used in designing of the torpedo-charge and the torpedo-head. It is reported that the torpedo-charge is a set of individual torpedos made of polyethylene pipes of length 1500 mm connected to each other with the help of couplings and splints. The torpedo-head consists of a polyethylene pipe of length 700 mm with wall thickness 15-17 mm filled with bulk explosives. Within the torpedo there are 2 explosive charges with electric-detonators for instantaneous action. The main cables of the explosive circuit are connected to the electric detonators and are passed through the packing pipe. In the improved design of the torpedo-head and the torpedo-charge, there are no metal parts. This excludes blow-out of particles of incandescent metal during the explosion and increases the level of work safety. The torpedo-charge is installed manually or mechanically with the help of a metal guide (rammer) which is removed from the well after it delivers the torpedo-charge.

  9. 双卡式杆式泵的研制及应用%Development and Application of Double Clamping Rod Pump

    Institute of Scientific and Technical Information of China (English)

    牛彩云; 张宏福; 甘庆明; 李大建

    2014-01-01

    Oil wells in Changqing oilfield buried deep,low single well production.In order to reduce the cost of operation,a set top drum fixed,mechanical,dual card dual seal cup rod pump were de-veloped,basic structure was composed by oil pump,bearing set and blowout preventer.After field application 5 000 wells,the test results show that,the sucker rod pump inspection period is about tube pump 2/3,downhole operation volume tube pump 15%,an oil pipe ratio cases reached 70%. Rod pump structure itself is an important influencing factor.This paper Article from the rod pump support assembly,valve structure and the support assembly and tubing with the size analy-zes three aspects of the cause of failure rod pump,also pointed out that the promotion of rod pump is a very long way,only to achieve standardization,serialization,universal,can really play a rod pump advantage.%长庆油田油井埋藏深、单井产量低,为降低作业成本,研制了定筒式顶部固定、机械与皮碗双密封的双卡式杆式泵。现场应用5000口井,试验结果表明:杆式泵检泵周期约为管式泵的2/3,井下作业总量较管式泵高15%,起油管比例达到70%。杆式泵自身结构是一个重要的影响因素,从杆式泵支撑总成、泵阀结构以及支撑总成与油管配合尺寸3个方面深入剖析了杆式泵产生故障的原因,只有实现了标准化、系列化、通用化,才能真正发挥杆式泵优势。

  10. DRSPALL :spallings model for the Waste Isolation Pilot Plant 2004 recertification.

    Energy Technology Data Exchange (ETDEWEB)

    Gilkey, Amy P. (GRAM Inc., Albuquerque, NM); Hansen, Clifford W.; Schatz, John F. (John F. Schatz Research & Consulting, Inc., Del Mar, CA); Rudeen, David Keith (GRAM Inc., Albuquerque, NM); Lord, David L.

    2006-02-01

    This report presents a model to estimate the spallings releases for the Waste Isolation Pilot Plant Performance Assessment (WIPP PA). A spallings release in the context of WIPP PA refers to a portion of the solid waste transported from the subsurface repository to the ground surface due to inadvertent oil or gas drilling into the WIPP repository at some time after site closure. Some solid waste will be removed by the action of the drillbit and drilling fluid; this waste is referred to as cuttings and cavings. If the repository is pressurized above hydrostatic at the time of intrusion, solid waste material local to the borehole may be subject to mechanical failure and entrainment in high-velocity gases as the repository pressure is released to the borehole. Solid material that fails and is transported into the wellbore and thus to the surface comprise the spallings releases. The spallings mechanism is analogous to a well blowout in the modern oil and gas drilling industry. The current spallings conceptual model and associated computer code, DRSPALL, were developed for the 2004 recertification because the prior spallings model used in the 1996 WIPP Compliance Certification Application (CCA) was judged by an independent peer review panel as inadequate (DOE 1996, 9.3.1). The current conceptual model for spallings addresses processes that take place several minutes before and after a borehole intrusion of a WIPP waste room. The model couples a pipe-flow wellbore model with a porous flow repository model, allowing high-pressure gas to flow from the repository to the wellbore through a growing cavity region at the well bottom. An elastic stress model is applied to the porous solid domain that allows for mechanical failure of repository solids if local tensile stress exceeds the tensile strength of the waste. Tensile-failed solids may be entrained into the wellbore flow stream by a fluidized bed model, in which case they are ultimately transported to the land surface

  11. DQX-Ⅲ型旋转防喷器的研制与应用%Development and Application of Model DQX- Ⅲ Rotary BOP

    Institute of Scientific and Technical Information of China (English)

    谢从辉

    2012-01-01

    由于大庆油田浅层井的现场施工条件限制,传统的旋转防喷器无法安装在低底座的井架上,同时不能满足高转速的要求。为此,研制了DQX-Ⅲ型旋转防喷器。它由旋转总成、壳体和泵站等3部分组成,采用全油循环的方式,润滑和冷却效果良好,能有效延长轴承和动密封的使用寿命,在浅层井中能保证钻进的连续性,优选的Kalsi动密封的结构和材质配方设计可大大延长其使用寿命。室内及现场试验结果表明,DQX-Ⅲ型旋转防喷器的动密封扭矩平稳,在浅层能用PDC钻头高速钻进,各项性能指标达到设计要求。%Due to the limits of the field operating conditions in shallow wells of Daqing Oilfield, the traditional rotary blowout pre-venter (BOP) cannot be installed on the derrick with a low substruetue. Meanwhile, the requirement of high speed rotation cannot be sat-isfied. Therefore, Model DQX -Ⅲ rotary BOP was developed. It consists of rotary assembly, shell body and pumping station. It adopts the all-oil circulation mode. The lubrication and cooling effect is desirable. It can effectively lengthen the service life of bearing and dy-namic seal. The drilling continuity can be ensured in shallow wells. The structure of the optimized Kalsi dynamic seal and the design of material formulation can lengthen its service life remarkably. The laboratory and field tests show that the torque of the BOP is smooth. It can carry out high speed drilling with the PDC bit in shallow layers. All indexes of performance have reached the design requirement.

  12. 两种不同内固定材料和植骨材料治疗胸腰椎椎体骨折的疗效分析%Effect of two different internal fixation and bone graft on patients with thoracic or lumbar spinal fracture

    Institute of Scientific and Technical Information of China (English)

    孟新文; 边江; 禹晓东

    2011-01-01

    目的:研究经后路复位内固定并行伤椎植骨对胸、腰椎骨折的治疗效果.方法:对椎体压缩性骨折和爆裂性骨折使用AF或钉棒系统复位固定后,经伤椎椎弓根向伤椎植入自固化磷酸钙人工骨和同种异体骨的治疗结果进行分析.结果:治疗432例 468椎,手术后椎体高度即刻恢复100%的319椎;95%以上80椎;90%以上60椎;80%以上的9椎.398例获得随访,随访10月~8年,伤椎均获得骨性愈合,脊柱稳定性及运动功能恢复良好.结论:胸、腰椎椎体骨折经AF或钉棒系统复位固定后,伤椎植入自固化磷酸钙人工骨和同种异体骨的疗效确切,效果优良.%Objective:To investigate the effect of two different internal fixation system and bone graft on patients with thoracic or lumbar spinal fracture. Methods: From April,2001 to June,2008, 468 body of vertebral in 432 patients suffered from compression fracture or blowout fracture were randomly selected to be treated with AF fixation system and screw - baculum fixation system, then artificial bone of calcium acid phosphate and homogeneity bone were transplanted into the vertebral body of fracture through neck of vertebra. Postoperatively, radiographic finding and clinical results were observed. Results: Instantly after operation, the height of 319 vertebral body were recovered completely ( 100% ), 80 recovered 95%, 60 recovered 90% and 9 recovered 80%. A total of 398 patients were followed - up after surgery, ranging from 10 months to 8 years. Radiographs showed all patients have got the bone union, the movement function of spine was significantly relieved and none suffered from low back pain or radicular pain. Neither complications nor instrumentation failure were observed. Conclusion:Internal fixation system and transplantation of bone graft through neck of vertebra could be recommended for treatment of thoracic or lumbar spinal fracture.

  13. Energy Spread Reduction of Electron Beams Produced via Laser Wake

    Energy Technology Data Exchange (ETDEWEB)

    Pollock, Bradley Bolt [Univ. of California, San Diego, CA (United States)

    2012-01-01

    Laser wakefield acceleration of electrons holds great promise for producing ultra-compact stages of GeV scale, high quality electron beams for applications such as x-ray free electron lasers and high energy colliders. Ultra-high intensity laser pulses can be self-guided by relativistic plasma waves over tens of vacuum diffraction lengths, to give >1 GeV energy in cm-scale low density plasma using ionization-induced injection to inject charge into the wake at low densities. This thesis describes a series of experiments which investigates the physics of LWFA in the self-guided blowout regime. Beginning with high density gas jet experiments the scaling of the LWFA-produced electron beam energy with plasma electron density is found to be in excellent agreement with both phenomenological theory and with 3-D PIC simulations. It is also determined that self-trapping of background electrons into the wake exhibits a threshold as a function of the electron density, and at the densities required to produce electron beams with energies exceeding 1 GeV a different mechanism is required to trap charge into low density wakes. By introducing small concentrations of high-Z gas to the nominal He background the ionization-induced injection mechanism is enabled. Electron trapping is observed at densities as low as 1.3 x 1018 cm-3 in a gas cell target, and 1.45 GeV electrons are demonstrated for the first time from LWFA. This is currently the highest electron energy ever produced from LWFA. The ionization-induced trapping mechanism is also shown to generate quasi-continuous electron beam energies, which is undesirable for accelerator applications. By limiting the region over which ionization-induced trapping occurs, the energy spread of the electron beams can be controlled. The development of a novel two-stage gas cell target provides the capability to tailor the gas composition in the longitudinal direction, and confine the trapping process to occur only in a

  14. Numerical Simulation on Hazard Zone Determination During the Dispersion of Natural Gas Containing Carbon Dioxide%含二氧化碳天然气云团扩散危险区域确定的数值模拟

    Institute of Scientific and Technical Information of China (English)

    马世海; 黄平; 杨智超; 蔡晓军

    2011-01-01

    The explosion characteristics and hazards caused by dispersion of the natural gas containing carbon dioxide are concerned about. In order to confirm the hazard zone determination during the dispersion of natural gas containing carbon dioxide, explosion characteristics and the accuracy evaluation for the numerical model, mechanism of the puff dispersion and dispersion issues caused by blowout were investigated by numerical simulation methods. A dispersion model of natural gas containing carbon dioxide was set up, and the dispersion evolvement was researched in detail, furthermore, the hazard zone concluding asphyxiation and explosion or flammability is defined. The numerical simulation results show that the flammability zone caused by the puff dispersion of the natural gas containing carbon dioxide takes on an irregular cirque distribution. Along-wind variation of flammability-zone dimension is larger than that for crosswind. For both cases of along-wind and crosswind, the distribution of variations of flammability zone with time presents the shape of parabola whose peak point is up. Besides, it does not matter to judge explosive zone based on time or on space, the affected area for flammability zone is way smaller than that for the asphyxia zone.%为确定含二氧化碳天然气云团扩散的危险区域范围,借助数值模拟方法建立了含二氧化碳天然气云团扩散模型.详细研究了含二氧化碳天然气云团扩散过程,确定了包括窒息和燃爆在内的2种危险区域.研究结果表明,含二氧化碳天然气云团扩散中燃爆区域呈不规则圆环状分布,燃爆区域的横风向尺度变化不大,而平行于风向的方向变化较大.无论横风向还是顺风向,燃爆区域尺度随时间的变化都呈开口朝下的抛物线形分布.高含二氧化碳天然气云团扩散后形成的燃爆区域无论从时间还是空间尺度看,波及的范围都远小于窒息性危险区域.

  15. 超燃发动机混合效率评估方法探讨%Evaluation methods of the fuel mixing efficiency for Scramjet

    Institute of Scientific and Technical Information of China (English)

    张弯洲; 乐嘉陵; 田野; 杨顺华; 邓维鑫; 程文明

    2012-01-01

    Three commonly-used evaluation methods for scramjet were summarized and analyzed,to improve the precision and objectivity for mixing evaluation,three new methods were imposed:the flow-field mixing efficiency,the flammable mixing efficiency and the flammable region percentage.The flow-field mixing efficiency can estimate the mixing performance of the flow structure and the effect of the mixing enhancement measurements.The flammable mixing efficiency and the flammable region percentage that took the flow-field blowout limits into consideration can connect with the ignition and combustion directly,objectively estimate the mixing efficiency for different lean and rich regions,and predict the region that combustion may occur.Then the three methods are verified and compared with the existed methods by two-dimension computational cases.%总结和分析了3种常用的典型混合效率评估方法,为了提高对混合程度的评估精度和客观性,提出了3种新的混合程度评估方法和指标:流场混合效率,可燃混合效率和适燃区域比例,流场混合效率能够客观评估流场结构的混合性能和增混措施的效果;可燃混合效率和适燃区域比例,结合了流场中的熄火边界参数,能够将燃料的分布及混合程度直接与点火燃烧联系,能够客观评估不同程度的贫油和富油流场的混合程度,能够合理地预测燃烧可能发生的区域,最后通过二维算例比较了新旧方法的评估结果,验证了新评估方法的合理性。

  16. Coupled LBM-DEM Three-phase Simulation on Gas Flux Seeping from Marine Sediment

    Science.gov (United States)

    Kano, Y.; Sato, T.

    2014-12-01

    One of the main issues of the geological storage of CO2 under the seabed is a risk of CO2 leakage. Once CO2seeps into the ocean, it rises in water column dissolving into seawater, which results in the acidification of seawater and/or returning to the air. Its behaviour significantly depends on flow rate and bubble size (Kano et al., 2009; Dewar et al., 2013). As for porous media, bubble size is generally predicted through simple force balance based on flow rate, surface tension and channel size which is estimated by porosity and grain size. However, in shallow marine sediments, grains could be mobilised and displaced by buoyant gas flow, which causes distinctive phenomena such as blow-out or formation of gas flow conduit. As a result, effective gas flux into seawater can be intermissive, and/or concentrated in narrow area (QICS, 2012; Kawada, 2013). Bubble size is also affected by these phenomena. To predict effective gas flux and bubble size into seawater, three-phase behaviour of gas-water-sediment grains should be revealed. In this presentation, we will report the results of gas-liquid-solid three-phase simulations and their comparisons with experimental and observation data. Size of solid particles is based on grain size composing marine sediments at some CCS project sites. Fluid-particle interactions are solved using the lattice Boltzmann method (LBM), while the particle-particle interactions are treated by coupling with the Discrete Element method (DEM). References: Dewar, M., Wei, W., McNeil, D., Chen, B., 2013. Small-scale modelling of the physiochemical impacts of CO2leaked from sub-seabed reservoirs or pipelines within the North Sea and surrounding waters. Marine Pollution Bulletin 73(2), 504-515. Kano, Y., Sato, T., Kita, J., Hirabayashi, S., Tabeta, S., 2009. Model prediction on the rise of pCO2 in uniform flows by leakage of CO2purposefully stored under the seabed. Int. J. Greenhouse Gas Control, Vol. 3(5), 617-625. Kawada, R. 2014. A study on the

  17. Crushed Exoplanet systems: Did it happen here?

    Science.gov (United States)

    Volk, Kathryn; Gladman, Brett

    2015-01-01

    Kepler revealed the common existence of tightly-packed super-Earth systems around solar-type stars, existing entirely inside the orbit of our Venus. Those systems must be stable for the ages of their host stars (~10^9 years); their formation mechanism must provide inter-planet spacings that permit long-term stability. If one postulates that most planetary systems form with tightly-packed inner planets, their current absence in some systems could be explained by the collisional destruction of the inner system after a period of meta-stability. The signatures of intense collisional environments have been observed around stars in the form of rapidly varying debris disks; in these disks the collisional products of the ensuing cascade are disposed of via drag down onto the star or grinding to the nearly instantaneous dust blow-out limit.We posit that our Solar System also originally had a system of multiple planets interior to the orbit of Venus. This would resolve a known issue that the energy/angular momentum of our inner-planet system is best explained by accreting the current terrestrial planets from a disk limited to 0.7-1.1 AU; in our picture the disk material closer to the Sun also formed planets, but they have since been destroyed. By studying the orbital stability of systems like the known Kepler systems, we demonstrate that orbital excitation and collisional destruction could be confined to just the inner parts of the system. In this scenario, Mercury is the final remnant of the inner system's destruction via a violent multi-collision (and/or hit-and-run disruption) process.This would provide a natural explanation for Mercury's unusually high eccentricity and orbital inclination; it also fits into the general picture of long-timescale secular orbital instability, with Mercury's current orbit being unstable on 5 Gyr time scales. The common decade spacing of instability time scales raises the intriguing possibility that this destruction occurred roughly 0.6 Gyr

  18. Novel Techniques for High Pressure Falling Sphere Viscosimetry under Simulated Earth's Mantle Conditions

    Science.gov (United States)

    Mueller, H. J.; Beckmann, F.; Dobson, D. P.; Hunt, S. A.; Secco, R.; Lauterjung, J.; Lathe, C.

    2014-12-01

    Viscosity data of melts measured under in situ high pressure conditions are crucial for the understanding of Earth's lower mantle and the interior of terrestrial and extrasolar Super-Earth planets. We report recent technical advances and techniques enabling falling sphere viscosity measurements in single- and double-stage DIA-type multi-anvil apparatus. For the experiments we used presses with a maximum load of 250 tons and 1750 tons. We anticipate that our system will enable viscosity measurements up to the maximum pressure for non-diamond anvils, i.e. pressures up to some 30 GPa. For the development of the new set ups the deformation of the cell assemblies were analyzed by X-ray absorption tomography at beamline W II at DESY/HASYLAB after the high pressure runs. These analysis gave considerable insights into strategies for improving the cell assembly with the result that the optimized assemblies could be used at much higher pressures without blow-outs. We think this approach is much faster and more beneficial than the classical way of trial and error. Additionally to prevent high pressure blow outs the task was to make the whole melting chamber accessible for the high pressure X-radiography system up to the maximum pressures. This way the accuracy and reliability of the measurements can be improved. For this goal we used X-ray transparent cBN-anvils at the single-stage DIA large volume press. Because this material is recently not available for the cube size of 32 mm this aproach did not work for the double-stage DIA. As a very useful and economical alternative we used slotted carbide anvils filled with fired pyrophyllite bars. To improve the frame quality of the platinum spheres taken by the CCD-camera the energy of the monochromatic X-rays had to be increased to 100 keV. The resulting ascent of scattered radiation required a new design of the X-radiography unit. Our results are demonstrated with viscosity measurements following Stokes law by evaluation of X

  19. SEM Characterization of Extinguished Grains from Plasma-Ignited M30 Charges

    Science.gov (United States)

    Kinkennon, A.; Birk, A.; DelGuercio, M.; Kaste, P.; Lieb, R.; Newberry, J.; Pesce-Rodriguez, R.; Schroeder, M.

    2000-01-01

    M30 propellant grains that had been ignited in interrupted closed bomb experiments were characterize by scanning electron microscopy (SEM). Previous chemical analysis of extinguished grains had given no indications of plasma-propellant chemical interactions that could explain the increased burning rates that had been previously observed in full-pressure closed bomb experiments. (This does not mean that there is no unique chemistry occurring with plasma ignition. It may occur very early in the ignition event and then become obscured by the burning chemistry.) In this work, SEM was used to look at grain morphologies to determine if there were increases in the surface areas of the plasma-ignited grains which would contribute to the apparent increase in the burning rate. Charges were made using 30 propellant grains (approximately 32 grams) stacked in two tiers and in two concentric circles around a plastic straw. Each grain was notched so that, when the grains were expelled from the bomb during extinguishment, it could be determined in which tier and which circle each grain was originally packed. Charges were ignited in a closed bomb by either a nickel wire/Mylar-capillary plasma or black powder. The bomb contained a blowout disk that ruptured when the pressure reached 35 MPa, and the propellant was vented into a collection chamber packed with polyurethane foam. SEM analysis of the grains fired with a conventional black powder igniter showed no signs of unusual burning characteristics. The surfaces seemed to be evenly burned on the exteriors of the grains and in the perforations. Grains that had been subjected to plasma ignition, however, had pits, gouges, chasms, and cracks in the surfaces. The sides of the grains closest to the plasma had the greatest amount of damage, but even surfaces facing the outer wall of the bomb had small pits. The perforations contained gouges and abnormally burned regions (wormholes) that extended into the web. The SEM photos indicated that

  20. Opposed Jet Burner Extinction Limits: Simple Mixed Hydrocarbon Scramjet Fuels vs Air

    Science.gov (United States)

    Pellett, Gerald L.; Vaden, Sarah N.; Wilson, Lloyd G.

    2007-01-01

    capacity. The new FS results refine our earlier idealized reactivity scale that shows wide ranging (50 x) diameter-normalized FSs for various HCs. These range from JP-10 and methane to H2 air, which produces an exceptionally strong flame that agrees within approx. 1% of recent 2-D numerically simulations. Finally, we continue advocating the FS approach as more direct and fundamental, for assessing idealized scramjet flameholding potentials, than measurements of unstrained laminar burning velocity or blowout in a Perfectly Stirred Reactor.