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. Risk assessment for SAGD well blowouts

    Energy Technology Data Exchange (ETDEWEB)

    Worth, D.; Alhanati, F.; Lastiwka, M. [C-FER Technologies, Edmonton, AB (Canada); Crepin, S. [Petrocedeno, Caracas (Venezuela)

    2008-10-15

    This paper discussed a steam assisted gravity drainage (SAGD) pilot project currently being conducted in Venezuela's Orinoco Belt. A risk assessment was conducted as part of the pilot program in order to evaluate the use of single barrier completions in conjunction with a blowout response plan. The study considered 3 options: (1) an isolated double barrier completion with a downhole safety valve (DHSV) in the production tubing string and a packer in the production casing annulus; (2) a partially isolated completion with no DHSV and a packer in the production casing annulus; and (3) an open single barrier completion with no additional downhole barriers. A reservoir model was used to assess the blowout flowing potential of SAGD well pairs. The probability of a blowout was estimated using fault tree analysis techniques. Risk was determined for various blowout scenarios, including blowouts during normal and workover operations, as well as blowouts through various flow paths. Total risk for each completion scenario was also determined at 3 different time periods within the production life of the well pair. The possible consequences of a blowout were assessed using quantitative consequence models. Results of the study showed that environmental and economic risks were much higher for the open completion technique. Higher risks were also associated with the earlier life of the completion strings. 20 refs., 3 tabs., 19 figs.

  3. PHYSICAL PARAMETERS OF STANDARD AND BLOWOUT JETS

    International Nuclear Information System (INIS)

    The X-ray Telescope on board the Hinode mission revealed the occurrence, in polar coronal holes, of much more numerous jets than previously indicated by the Yohkoh/Soft X-ray Telescope. These plasma ejections can be of two types, depending on whether they fit the standard reconnection scenario for coronal jets or if they include a blowout-like eruption. In this work, we analyze two jets, one standard and one blowout, that have been observed by the Hinode and STEREO experiments. We aim to infer differences in the physical parameters that correspond to the different morphologies of the events. To this end, we adopt spectroscopic techniques and determine the profiles of the plasma temperature, density, and outflow speed versus time and position along the jets. The blowout jet has a higher outflow speed, a marginally higher temperature, and is rooted in a stronger magnetic field region than the standard event. Our data provide evidence for recursively occurring reconnection episodes within both the standard and the blowout jet, pointing either to bursty reconnection or to reconnection occurring at different locations over the jet lifetimes. We make a crude estimate of the energy budget of the two jets and show how energy is partitioned among different forms. Also, we show that the magnetic energy that feeds the blowout jet is a factor of 10 higher than the magnetic energy that fuels the standard event

  4. PHYSICAL PARAMETERS OF STANDARD AND BLOWOUT JETS

    Energy Technology Data Exchange (ETDEWEB)

    Pucci, Stefano; Romoli, Marco [Department of Physics and Astronomy, University of Firenze, I-50121 Firenze (Italy); Poletto, Giannina [INAF-Arcetri Astrophysical Observatory, I-50125 Firenze (Italy); Sterling, Alphonse C., E-mail: stpucci@arcetri.astro.it [Space Science Office, NASA/MSFC, Huntsville, Al 35812 (United States)

    2013-10-10

    The X-ray Telescope on board the Hinode mission revealed the occurrence, in polar coronal holes, of much more numerous jets than previously indicated by the Yohkoh/Soft X-ray Telescope. These plasma ejections can be of two types, depending on whether they fit the standard reconnection scenario for coronal jets or if they include a blowout-like eruption. In this work, we analyze two jets, one standard and one blowout, that have been observed by the Hinode and STEREO experiments. We aim to infer differences in the physical parameters that correspond to the different morphologies of the events. To this end, we adopt spectroscopic techniques and determine the profiles of the plasma temperature, density, and outflow speed versus time and position along the jets. The blowout jet has a higher outflow speed, a marginally higher temperature, and is rooted in a stronger magnetic field region than the standard event. Our data provide evidence for recursively occurring reconnection episodes within both the standard and the blowout jet, pointing either to bursty reconnection or to reconnection occurring at different locations over the jet lifetimes. We make a crude estimate of the energy budget of the two jets and show how energy is partitioned among different forms. Also, we show that the magnetic energy that feeds the blowout jet is a factor of 10 higher than the magnetic energy that fuels the standard event.

  5. 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....

  6. Twist in a polar blowout jet

    Institute of Scientific and Technical Information of China (English)

    Jun-Chao Hong; Yun-Chun Jiang; Jia-Yan Yang; Rui-Sheng Zheng; Yi Bi; Hai-Dong Li; Bo Yang

    2013-01-01

    It is well known that some coronal jets exhibit helical structures and untwisting.We attempt to inspect the origin of twist in a blowout jet.By means of multiwavelength and multi-angle observations from Solar Dynamics Observatory (SDO)and Solar Terrestrial Relations Observatory-Ahead (STEREO-A),we firstly report a polar untwisting jet that is a blowout jet which leads to a jet-like coronal mass ejection.From the viewpoint of SDO,the jet shows clear untwisting behavior and two jet-spires.However,from the viewpoint of STEREO-A the jet actually comes from the whiplike prominence eruption and is followed by a white-light jet.Our observations indicate that twist in blowout jets may result from the erupting mini-prominences/minifilaments in the jet base.

  7. 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.

  8. Organized investigation expedites insurance claims following a blowout

    International Nuclear Information System (INIS)

    Various types of insurance policies cover blowouts to different degrees, and a proper understanding of the incident and the coverage can expedite the adjustment process. Every well control incident, and the claim arising therefrom, has a unique set of circumstances which must be analyzed thoroughly. A blowout incident, no matter what size or how severe, can have an emotional impact on all who become involved. Bodily injuries or death of friends and coworkers can result in additional stress following a blowout. Thus, it is important that all parties involved remain mindful of sensitive matters when investigating a blowout. This paper reviews the definition of a blowout based on insurance procedures and claims. It reviews blowout expenses and contractor cost and accepted well control policies. Finally, it reviews the investigation procedures normally followed by an agent and the types of information requested from the operator

  9. 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...

  10. Quantitative assessment of blowout data as it relates to pollution potential

    International Nuclear Information System (INIS)

    This paper reports on a large blowout database that has been developed. It has been analyzed for various trends and quantitative data relating to blowouts and pollution. Pollution from blowouts is a rate occurrence and has a low probability. However, when an event occurs, it may involve large spill volumes. Blowout trends have been analyzed for some well control purposes. Techniques to mitigate pollution damage from an offshore blowout are presented

  11. DICHOTOMY OF SOLAR CORONAL JETS: STANDARD JETS AND BLOWOUT JETS

    International Nuclear Information System (INIS)

    By examining many X-ray jets in Hinode/X-Ray Telescope 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 Hα macrospicules, jets in which the jet-base magnetic arch undergoes a miniature version of the blowout eruptions that produce major coronal mass ejections. 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 A 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 ∼ 104 - 105 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.

  12. 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.

  13. Oil deposition modeling for surface oil well blowouts

    Energy Technology Data Exchange (ETDEWEB)

    Belore, R. [S.L. Ross Environmental Research Ltd., Ottawa, ON (Canada); McHale, J. [Alaska Clean Seas, Anchorage, AK (United States); Chapple, T. [Alaska Dept. of Environmental Conservation, Anchorage, AK (United States)

    1998-09-01

    A project was conducted by Alaska Clean Seas to determine the likely fallout zone from a surface oil or gas well blowout, under specific conditions and blowout characteristics, for spill response planning purposes. A surface oil and gas blowout can cause a plume of oil droplets into the atmosphere near the discharge site. The place and rate at which the oil will fall to the ground depends on the following parameters: (1) the height to which the oil is propelled, (2) the size of the oil drops, and (3) the prevailing wind speed. A modeling method was presented for estimating the fallout width and rate as a function of distance from the source, for the range of oil and gas flows likely to occur in the Alaska North Slope operations. 5 refs., 1 tab., 6 figs.

  14. Oil deposition modeling for surface oil well blowouts

    International Nuclear Information System (INIS)

    A project was conducted by Alaska Clean Seas to determine the likely fallout zone from a surface oil or gas well blowout, under specific conditions and blowout characteristics, for spill response planning purposes. A surface oil and gas blowout can cause a plume of oil droplets into the atmosphere near the discharge site. The place and rate at which the oil will fall to the ground depends on the following parameters: (1) the height to which the oil is propelled, (2) the size of the oil drops, and (3) the prevailing wind speed. A modeling method was presented for estimating the fallout width and rate as a function of distance from the source, for the range of oil and gas flows likely to occur in the Alaska North Slope operations. 5 refs., 1 tab., 6 figs

  15. Serum albumin is an important prognostic factor for carotid blowout syndrome

    International Nuclear Information System (INIS)

    Carotid blowout syndrome is a severe complication of head and neck cancer. High mortality and major neurologic morbidity are associated with carotid blowout syndrome with massive bleeding. Prediction of outcomes for carotid blowout syndrome patients is important for clinicians, especially for patients with the risk of massive bleeding. Between 1 January 2001 and 31 December 2011, 103 patients with carotid blowout syndrome were enrolled in this study. The patients were divided into groups with and without massive bleeding. Prognostic factors were analysed with proportional hazard (Cox) regressions for carotid blowout syndrome-related prognoses. Survival analyses were based on the time from diagnosis of carotid blowout syndrome to massive bleeding and death. Patients with massive bleeding were more likely to have hypoalbuminemia (albumin1000 cells/μl, P=0.041) and hypoalbuminemia (P=0.010) were important to prognosis. Concurrent chemoradiotherapy (P=0.007), elevated lactate dehydrogenase (>250 U/l; P=0.050), local recurrence (P=0.022) and hypoalbuminemia (P=0.038) were related to poor prognosis in carotid blowout syndrome-related death. In multivariate analysis, best supportive care and hypoalbuminemia were independent factors for both carotid blowout syndrome-related massive bleeding (P=0.000) and carotid blowout syndrome-related death (P=0.013), respectively. Best supportive care and serum albumin are important prognostic factors in carotid blowout syndrome. It helps clinicians to evaluate and provide better supportive care for these patients. (author)

  16. Flamingwagon: Athey Wagon braves heat to aid oilpatch blowout response

    Energy Technology Data Exchange (ETDEWEB)

    Leschart, M.

    2002-09-01

    Construction of an Athey wagon by Key Safety Ltd at the company's Red Deer, Alberta facilities is announced. At present, the wagon is awaiting only the installation of its fire-prevention system to be ready for action. The last such blowout response equipment was built in Alberta 40 years ago, and when Crestar Energy lost control of a horizontal sour well during a recent drilling in the Little Bow area, a unit built in 1954 and housed in a museum at the Leduc No. 1 historic site in Devon, Alberta, had to be pressed into service to deal with the emergency. While Athey wagons are not always essential to the blow-out control process, the addition of this new piece of well control safety equipment is welcome news, especially in the light of the new knowledge gained, and innovative processes and procedures developed by Canadian companies fighting oil field fires in Kuwait after the Gulf War.

  17. Modeling Blowouts During Drilling Using STAMP and STPA

    OpenAIRE

    Budde, Silje Frost

    2012-01-01

    The focus of this master thesis has been on modeling the risk of blowouts during drilling using System-Theoretic Accident Model and Processes (STAMP) and System-Theoretic Process Analysis (STPA). The world and technology are changing, but these changes are not reflected in our safety engineering approaches. Many of the basic assumptions of traditional techniques no longer hold for complex, high-technical systems being built today. STAMP is a new model based on systems theory rather than relia...

  18. A Review of Seafood Safety after the Deepwater Horizon Blowout

    OpenAIRE

    Gohlke, Julia M.; Doke, Dzigbodi; Tipre, Meghan; Leader, Mark; Fitzgerald, Timothy

    2011-01-01

    Background: The Deepwater Horizon (DH) blowout resulted in fisheries closings across the Gulf of Mexico. Federal agencies, in collaboration with impacted Gulf states, developed a protocol to determine when it is safe to reopen fisheries based on sensory and chemical analyses of seafood. All federal waters have been reopened, yet concerns have been raised regarding the robustness of the protocol to identify all potential harmful exposures and protect the most sensitive populations. Objectives:...

  19. Positron acceleration in doughnut wakefields in the blowout regime

    Science.gov (United States)

    Vieira, Jorge; Mendonca, Jose; Fonseca, Ricardo; Silva, Luis

    2014-10-01

    Most important plasma acceleration results were reached in the so called bubble or blowout regime. Although ideally suited for electron acceleration, it has been recognized that non-linear regimes are not adequate to accelerate positrons. New configurations enabling positron acceleration in non-linear regimes would therefore open new research paths for future plasma based collider configurations. In this work, we explore, analytically and through 3D OSIRIS simulations, a novel configuration for positron acceleration in strongly non-linear laser wakefield excitation regimes using Laguerre-Gaussian laser drivers to drive doughnut shaped wakefields with positron focusing and accelerating fields. We demonstrate that positron focusing-fields can be up to an order of magnitude larger than electron focusing in the spherical blowout regime. The amplitude of the accelerating fields is similar to the spherical blowout. Simulations demonstrate laser self-guiding and stable positron acceleration until the laser energy has been exhausted to the plasma. Other realisations of the scheme, using two Gaussian laser pulses, will also be explored. FCT Grant No EXPL/FIS-PLA/0834/2012 and European Research Council ERC-2010-AdG Grant No. 267841.

  20. Management of diplopia in patients with blowout fractures

    Directory of Open Access Journals (Sweden)

    Osman Melih Ceylan

    2011-01-01

    Full Text Available Purpose: To report the management outcomes of diplopia in patients with blowout fracture. Materials and Methods: Data for 39 patients with diplopia due to orbital blowout fracture were analyzed retrospectively. The inferior wall alone was involved in 22 (56.4% patients, medial wall alone was involved in 14 (35.8% patients, and the medial and inferior walls were involved in three (7.6% patients. Each fracture was reconstructed with a Medpore® implant. Strabismus surgery or prism correction was performed in required patients for the management of persistent diplopia. Mean postoperative follow up was 6.5 months. Results: Twenty-three (58.9% patients with diplopia underwent surgical repair of blowout fracture. Diplopia was eliminated in 17 (73.9% patients following orbital wall surgery. Of the 23 patients, three (7.6% patients required prism glasses and another three (7.6% patients required strabismus surgery for persistent diplopia. In four (10.2% patients, strabismus surgery was performed without fracture repair. Twelve patients (30.7% with negative forced duction test results were followed up without surgery. Conclusions: In our study, diplopia resolved in 30.7% of patients without surgery and 69.2% of patients with diplopia required surgical intervention. Primary gaze diplopia was eliminated in 73.9% of patients through orbital wall repair. The most frequently employed secondary surgery was adjustable inferior rectus recession and <17.8% of patients required additional strabismus surgery.

  1. Dune field reactivation from blowouts: Sevier Desert, UT, USA

    Science.gov (United States)

    Barchyn, Thomas E.; Hugenholtz, Chris H.

    2013-12-01

    Dune field reactivation (a shift from vegetated to unvegetated state) has important economic, social, and environmental implications. In some settings reactivation is desired to preserve environmental values, but in arid regions reactivation is typically a form of land degradation. Little is known about reactivation due to a lack of published records, making modeling and prediction difficult. Here we detail dune reactivations from blowout expansion in the Sevier Desert, Utah, USA. We use historical aerial photographs and satellite imagery to track the transition from stable, vegetated dunes to actively migrating sediment in 3 locations. We outline a reactivation sequence: (i) disturbance breaches vegetation and exposes sediment, then (ii) creates a blowout with a deposition apron that (iii) advances downwind with a slipface or as a sand sheet. Most deposition aprons are not colonized by vegetation and are actively migrating. To explore causes we examine local sand flux, climate data, and stream flow. Based on available data the best explanation we can provide is that some combination of anthropogenic disturbance and climate may be responsible for the reactivations. Together, these examples provide a rare glimpse of dune field reactivation from blowouts, revealing the timescales, behaviour, and morphodynamics of devegetating dune fields.

  2. 30 CFR 250.516 - Blowout preventer system tests, inspections, and maintenance.

    Science.gov (United States)

    2010-07-01

    ... Well-Completion Operations § 250.516 Blowout preventer system tests, inspections, and maintenance. (a... 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...

  3. 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

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

    Science.gov (United States)

    Kim, Yong-Ha; Park, Youngsoo; Chung, Kyu Jin

    2016-05-01

    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. 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.

  6. Analysis of blowout fractures using cine mode MRI

    International Nuclear Information System (INIS)

    By observing conventional CT and MRI images, it is difficult to distinguish extension failure from adhesion, bone fracture or damage to the extraocular muscle, any one of which may be the direct cause of the eye movement disturbance accompanying blowout fracture. We therefore carried out dynamic analysis of eye movement disturbance using a cine mode MRI. We put seven fixation points in the gantry of the MRI and filmed eye movement disturbances by the gradient echo method, using a surface coil and holding the vision on each fixation point. We also video recorded the CRT monitor of the MRI to obtain dynamic MRI images. The subjects comprised 5 cases (7-23 years old). In 4 cases, we started orthoptic treatment, saccadic eye movement training, convergence training and fusional amplitude training after surgery, with only orthoptic treatment in the 5 th case. In all cases, fusion area improvement was recognized during training. In 2 cases examined by cine mode MRI before and after surgery, we observed improved eye movement after training, the effectiveness of which was thereby proven. Also, using cine mode MRI we were able to determine the character of incarcerated tissue and the cause of eye movement disturbance. We conclude that it blowout fracture, cine mode MRI may be useful in selecting treatment and observing its effectiveness. (author)

  7. Case history: blowout at an LPG storage cavern in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Hamberger, Ulrika

    1991-01-01

    A ''blowout'' occurred when an additional well was drilled to secure sufficient water pressure at an underground LPG storage cavern in September 1989. The leak was stopped after 12 hours. By grouting through the drill rod, it was possible to fill up the cavity around the drill bit. It was then possible to grout the hole up to ground level. The 48,000 m{sup 3}-capacity underground storage, which is located in Karlshamn on the south coast of Sweden, has been in operation since April 1990. Storage is accomplished under hydrostatic water conditions. The storage cavern is placed at such a depth so as to guarantee a sufficient groundwater pressure above the whole storage. A ''curtain'' of drill holes, which efficiently spread the groundwater, is placed above the cavern. The groundwater was carefully observed in wells during the excavation period and these observations continue. (author).

  8. Clinical features and MRI findings of blow-out fracture

    International Nuclear Information System (INIS)

    Precise anatomical understanding of orbital blow-out fracture lesions is necessary for the treatment of patients. Retrospectively, MRI findings were compared with the clinical features of pure type blow-out fractures and the efficacy of MRI in influencing a decision for surgical intervention was evaluated. Eighteen child (15 boys, 3 girls) cases were evaluated and compared with adult cases. The patients were classified into three categories (Fig.1) and two types (Fig.2) in accordance with the degree of protrusion of fat tissue. The degree of muscle protrusion also was divided into three categories (Fig. 3). Both muscle and fat tissue were protruding from the fracture site in 14 cases. Fat tissue protrusion alone was found in 3 cases. In contrast, no protrusion was seen in one case. The incarcerated type of fat prolapse was found in 40% of cases, while muscle tissue prolapse was found in 75% of patients. Marginal irregularity or swelling of muscle was observed in 11 patients. There was good correlation of ocular motor disturbance and MRI findings. Disturbance of eyeball movement was observed in all patients with either incarcerated fat tissue or marginal irregularity or swelling of muscle. In contrast, restriction of eyeball movement was rare in cases of no incarceration, even if the fracture was wide. Deformity or marginal irregularity of the ocular muscle demonstrated in MRI may suggest damage an adhesion to the muscle wall. When MRI reveals incarceration or severe prolapse of fat tissue, or deformity and marginal irregularity of the ocular muscle, surgical intervention should be considered. (author)

  9. Reactivation of supply-limited dune fields from blowouts: A conceptual framework for state characterization

    Science.gov (United States)

    Barchyn, Thomas E.; Hugenholtz, Chris H.

    2013-11-01

    Aeolian dune fields mantle the Earth in both vegetated (stable) and unvegetated (active) states. Changes in state are poorly understood; in particular, little is known about reactivation (devegetation) from a vegetated state. Available evidence indicates that dune reactivation can be driven by changes in aridity, increased wind speed, fire, biogenic disturbance, human disturbance, or a combination of the previous. How these controls fit together and define the reactivation potential of dune fields is presently unknown. Here we develop a framework to describe reactivation potential for a specific case: presently vegetated, supply-limited dune fields that develop blowouts under a unidirectional wind. We first define a conceptual model of blowout expansion, and then split the functions of vegetation in a stable dune field into: (i) maintenance of a protective skin, and (ii) blowout suppression. We model reactivation as disturbance breaking through the protective skin, which forms a blowout that is either (i) suppressed by colonizer species, or (ii) capable of advancing downwind and reactivating part of the dune field. The capacity for disturbance to break through the protective skin is a function of disturbance magnitude, area, and resistance of the skin. The blowout suppression capacity of a dune field is a function of sediment flux, blowout depth (related to geomorphology), and colonizer species vitality. By plotting a given dune field with two variables (protective skin breach rate and blowout suppression capacity) we define four states: (i) stable, (ii) blowout dominated, (iii) reactivating, or (iv) stable but disturbance susceptible. We reinforce the conceptual model with qualitative examples and discussion of experiments on grassland-stabilized dunes in Canada. Overall, our framework provides a starting point for quantifying the reactivation potential of vegetated dune fields.

  10. 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

  11. 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.

  12. An integrated model for prediction of oil transport from a deep water blowout

    International Nuclear Information System (INIS)

    The ability to accurately predict the behavior of a jet/plume is increasingly important as offshore oil development proceeds into deeper water and as concern over the possibility of blowouts increases. This paper presented a modified oil spill trajectory and fates model which made allowances for the prediction of the transport of oil from a deep water oil/gas blowout including hydrate formation/decomposition. The advective and dispersive transport of particulates in oil generated during a blowout were also included. The three components of this model were: (1) a blowout model, which predicts the plume centerline velocity, buoyancy, half width and trapping height, (2) a three-dimensional particle model, and (3) a surface spill model. Comparative evaluations between gas bubble driven plumes and model predictions were conducted to verify the model. A series of sensitivity studies were conducted at a blowout release depth of 1750 m to determine the impact of density gradient, entrainment coefficient and gas to oil ratio on the predictions of the plume radius and centerline velocity versus distance from the release and the plume trapping height. It was determined that in most cases the plume is trapped within 60 m of the release depth. The availability of the water to form hydrates is one of the principal process that controls plume dynamics. 48 refs., 1 tab., 10 figs

  13. Current concepts on the management of orbital blow-out fractures.

    Science.gov (United States)

    Koornneef, L

    1982-09-01

    Surgical versus nonsurgical treatment of orbital blow-out fractures has been controversial in the past. In the 1950s it was advocated that all blow-out fractures be treated surgically based on the conception that extraocular muscles were blown out and trapped in the fracture hole, causing double vision and enophthalmos. Gradually, however, a shift to a more conservative approach occurred, probably because of the complications of surgery, the disappointing results in improvement of motility and enophthalmos, and the growing evidence of spontaneous improvement of double vision. This article analyzes the literature chronologically and blends this analysis with the results of a new anatomical approach to the human orbit. New theories on the mechanism of blow-out fractures are postulated. No longer is entrapment of muslces in a blow-out fracture held responsible for the severe motility problems; rather it is viewed as caused by a dysfunction of the entire motility apparatus in the fracture region. Consequently, conventional surgical treatment, repairing the orbital floor only, seems to have lost its theoretical foundation and a conservative approach is advocated until microsurgical techniques become more readily avaliable to treat the sequelae of blow-out fractures at their origin. PMID:7137815

  14. 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. PMID:21889767

  15. LES of combustion dynamics near blowout in a realistic gas-turbine combustor

    Science.gov (United States)

    Esclapez, Lucas; Nik, Medhi B.; Ma, Peter C.; O'Brien, Jeff; Carbajal, Serena; Ihme, Matthias

    2015-11-01

    Driven by increasingly stringent emission regulations, modern gas turbines operate at lean conditions to reduce combustion chamber temperature and NOx emissions. However, as the combustor operates closer to the lean blow-out (LBO) limit, flame stabilization mechanisms are weakened, which increases the risk for complete flame blowout. To better understand the LBO-process, large-eddy simulations of the combustion dynamics near blowout are performed in a realistic two-phase flow combustor. An unstructured incompressible Navier-Stokes solver is used in combination with a Lagrangian dispersed phase formulation. Flame dynamics near and at LBO conditions are studied to identify the role of the liquid fuel composition, spray evaporation, and complex flow pattern on the LBO limit.

  16. 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.

  17. One-side riddled basin below and beyond the blowout bifurcation

    Science.gov (United States)

    Yang, H. L.

    2000-10-01

    In this Rapid Comunication we report a phenomenon of a one-side riddled basin where one side of the basin of attraction of an attractor on an invariant subspace (ISS) is globally riddled, while the other side is only locally riddled. This kind of basin appears due to the symmetry breaking with respect to the ISS. This one-side riddled basin can even persist beyond the blowout bifurcation, contrary to the previously reported riddled basins which exist only below the blowout transition. An experimental situation where this phenomenon can be expected is proposed.

  18. The effect of gas and oil well blowout emissions on livestock in Alberta

    International Nuclear Information System (INIS)

    Poisoning caused by emissions from sour gas well or oil well blowouts is not acute because the gases are diluted by the atmosphere before they reach livestock. Exposure may last a month or more and may produce a syndrome indistinguishable from common disorders of flu, malaise, mood change, and in the case of animals, lack of production or decreased production. Little information is available on the composition of releases from well blowouts, which may change due to concurrent reactions with oxygen and photodecomposition. Effects on livestock observed to results from sour gas plant emissions (mostly sulfur dioxide) include runny eyes in cattle, loss of production, diarrhea and abortion. Blowout emissions may contain oxidant gases as well as hydrogen sulfides. These products irritate mucous membranes, and can lead to pink eye. Respiratory problems may include upper respiratory tract infections, and may produce susceptibility to secondary pneumonia. Abortion, infertility and congenital effects are areas of concern. It is considered unlikely that hydrogen sulfide can cause such effects, however carbon disulfide and carbonyl sulfide, both present in sour gas blowouts, are known to have effects on the fetus. Effects on production and performance are unknown, and it is postulated that amounts of sulfur deposition are insufficient to cause nutrient deficiencies. Psychological reactions are suggested to explain some of the adverse effects of exposure to sour gas. 1 ref

  19. Corrigendum to "Dune field reactivation from blowouts: Sevier Desert, UT, USA" [Aeolian Res. 11 (2013) 75-84

    Science.gov (United States)

    Barchyn, Thomas E.; Hugenholtz, Chris H.

    2016-06-01

    This corrigendum corrects an error made in the flux calculations in 'Dune field reactivation from blowouts: Sevier Desert, UT, USA'. The corrected data differ only slightly from the original publication and do not affect the conclusions of the paper.

  20. Reliability Analysis of Blowout Preventer Systems: A comparative study of electro-hydraulic vs. all-electric BOP technology

    OpenAIRE

    Drægebø, Elisabeth

    2014-01-01

    A blowout preventer (BOP) is a large valve used to seal, control and monitor oil and gas wells. It serves as an important barrier against blowouts. Excessive downtime on the BOP is a problem for drilling companies worldwide, which causes increased costs and delays for everyone involved in a drilling project. The background for this thesis is Odfjell Drilling’s experience with downtime on the BOP during drilling operations on board their mobile offshore drilling units. The downtime and as...

  1. Spatial-temporal evolution of aeolian blowout dunes at Cape Cod

    Science.gov (United States)

    Abhar, Kimia C.; Walker, Ian J.; Hesp, Patrick A.; Gares, Paul A.

    2015-05-01

    This paper explores historical evolution of blowouts at Cape Cod National Seashore (CCNS), USA - a site that hosts one of the world's highest densities of active and stabilized blowouts. The Spatial-Temporal Analysis of Moving Polygons (STAMP) method is applied to a multi-decadal dataset of aerial photography and LiDAR to extract patterns of two-dimensional movement and morphometric changes in erosional deflation basins and depositional lobes. Blowout development in CCNS is characterized by several geometric (overlap) and movement (proximity) responses, including: i) generation and disappearance, ii) extension and contraction, iii) union or division, iv) clustering and v) divergence by stabilization. Other possible movement events include migration, amalgamation and proximal stabilization, but they were not observed in this study. Generation events were more frequent than disappearance events; the former were highest between 1985 and 1994, while the latter were highest between 2000 and 2005. High rates of areal change in erosional basins occurred between 1998 and 2000 (+ 3932 m2 a-1), the lowest rate (+ 333 m2 a-1) between 2005 and 2009, and the maximum rate (+ 4589 m2 a-1) between 2009 and 2011. Union events occurred mostly in recent years (2000-2012), while only one division was observed earlier (1985-1994). Net areal changes of lobes showed gradual growth from a period of contraction (- 1119 m2 a-1) between 1998 and 2000 to rapid extension (+ 2030 m2 a-1) by 2010, which is roughly concurrent with rapid growth of erosional basins between 2005 and 2009. Blowouts extended radially in this multi-modal wind regime and, despite odd shapes initially, they became simpler in form (more circular) and larger over time. Net extension of erosional basins was toward ESE (109°) while depositional lobes extended SSE (147°). Lobes were aligned with the strongest (winter) sand drift vector although their magnitude of areal extension was only 33% that of the basins. These

  2. Probabilistic blowout risk in former disputed area southeast in the Norwegian part of the Barents Sea.

    OpenAIRE

    Johnsen, Silje

    2012-01-01

    The maritime delimitation in the former disputed area between Norway and Russia was agreed upon in 2011. It is therefore probable that the area will be opened for petroleum exploration in the near future. A blowout represents one of the most severe threats associated with petroleum exploration. This thesis has investigated the risk involved with such an activity through a case study, by considering geology and well specific conditions for this area. Currently, no wells have been drilled in th...

  3. HORIZONTAL DRILLING ACTIVITY IN HUNGARY AND SPECIAL QUESTIONS OF BLOWOUT PREVENTION IN HORIZONTAL WELLS

    Directory of Open Access Journals (Sweden)

    Jozsef Szepesi

    1996-12-01

    Full Text Available Described is horizontal drilling in the world and data on such activity in Hungary. Results show that there is an increase of such activity in spite of complex problems in drilling and completion of horizontal wells. Since these wells are often drilled in partialy exhausted hydrocarbon fluid reservoirs with slightly over-balanced or even with under-balanced conditions, there is an increased danger of blowouts. Prevention methods and suggested procedures are elaborated.

  4. HORIZONTAL DRILLING ACTIVITY IN HUNGARY AND SPECIAL QUESTIONS OF BLOWOUT PREVENTION IN HORIZONTAL WELLS

    OpenAIRE

    Jozsef Szepesi

    1996-01-01

    Described is horizontal drilling in the world and data on such activity in Hungary. Results show that there is an increase of such activity in spite of complex problems in drilling and completion of horizontal wells. Since these wells are often drilled in partialy exhausted hydrocarbon fluid reservoirs with slightly over-balanced or even with under-balanced conditions, there is an increased danger of blowouts. Prevention methods and suggested procedures are elaborated.

  5. Orbital blow-out fractures: correlation of preoperative computed tomography and postoperative ocular motility.

    OpenAIRE

    Harris, G. J.; Garcia, G H; Logani, S C; Murphy, M L; Sheth, B P; Seth, A K

    1998-01-01

    BACKGROUND/PURPOSE: Although the management of orbital blow-out fractures was controversial for many years, refined imaging with computed tomography (CT) helped to narrow the poles of the debate. Many orbital surgeons currently recommend repair if fracture size portends late enophthalmos, or if diplopia has not substantially resolved within 2 weeks of the injury. While volumetric considerations have been generally well-served by this approach, ocular motility outcomes have been less than idea...

  6. Mechanisms of Flame Stabilization and Blowout in a Reacting Turbulent Hydrogen Jet in Cross-Flow

    Energy Technology Data Exchange (ETDEWEB)

    Kolla, H.; Grout, R. W.; Gruber, A.; Chen, J. H.

    2012-08-01

    The mechanisms contributing to flame stabilization and blowout in a nitrogen-diluted hydrogen transverse jet in a turbulent boundary layer cross-flow (JICF) are investigated using three-dimensional direct numerical simulation (DNS) with detailed chemistry. Non-reacting JICF DNS were performed to understand the relative magnitude and physical location of low velocity regions on the leeward side of the fuel jet where a flame can potentially anchor. As the injection angle is reduced from 90{sup o} to 70{sup o}, the low velocity region was found to diminish significantly, both in terms of physical extent and magnitude, and hence, its ability to provide favorable conditions for flame anchoring and stabilization are greatly reduced. In the reacting JICF DNS a stable flame is observed for 90{sup o} injection angle and, on average, the flame root is in the vicinity of low velocity magnitude and stoichiometric mixture. When the injection angle is smoothly transitioned to 75{sup o} a transient flame blowout is observed. Ensemble averaged quantities on the flame base reveal two phases of the blowout characterized by a kinematic imbalance between flame propagation speed and flow normal velocity. In the first phase dominant flow structures repeatedly draw the flame base closer to the jet centerline resulting in richer-than-stoichiometric mixtures and high velocity magnitudes. In the second phase, in spite of low velocity magnitudes and a return to stoichiometry, due to jet bending and flame alignment normal to the cross-flow, the flow velocity normal to the flame base increases dramatically perpetuating the blowout.

  7. Evolution of bubble size distribution from gas blowout in shallow water

    Science.gov (United States)

    Zhao, Lin; Boufadel, Michel C.; Lee, Kenneth; King, Thomas; Loney, Norman; Geng, Xiaolong

    2016-03-01

    Gas is often emanated from the sea bed during a subsea oil and gas blowout. The size of a gas bubble changes due to gas dissolution in the ambient water and expansion as a result of a decrease in water pressure during the rise. It is important to understand the fate and transport of gas bubbles for the purpose of environmental and safety concerns. In this paper, we used the numerical model, VDROP-J to simulate gas formation in jet/plume upon release, and dissolution and expansion while bubble rising during a relatively shallow subsea gas blowout. The model predictions were an excellent match to the experimental data. Then a gas dissolution and expansion module was included in the VDROP-J model to predict the fate and transport of methane bubbles rising due to a blowout through a 0.10 m vertical orifice. The numerical results indicated that gas bubbles would increase the mixing energy in released jets, especially at small distances and large distances from the orifice. This means that models that predict the bubble size distribution (BSD) should account for this additional mixing energy. It was also found that only bubbles of certain sizes would reach the water surfaces; small bubbles dissolve fast in the water column, while the size of the large bubbles decreases. This resulted in a BSD that was bimodal near the orifice, and then became unimodal.

  8. 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.

  9. A small-scale eruption leading to a blowout macrospicule jet in an on-disk coronal hole

    International Nuclear Information System (INIS)

    We examine the three-dimensional magnetic structure and dynamics of a solar EUV-macrospicule jet that occurred on 2011 February 27 in an on-disk coronal hole. The observations are from the Solar Dynamics Observatory (SDO) Atmospheric Imaging Assembly (AIA) and the SDO Helioseismic and Magnetic Imager (HMI). The observations reveal that in this event, closed-field-carrying cool absorbing plasma, as in an erupting mini-filament, erupted and opened, forming a blowout jet. Contrary to some jet models, there was no substantial recently emerged, closed, bipolar-magnetic field in the base of the jet. Instead, over several hours, flux convergence and cancellation at the polarity inversion line inside an evolved arcade in the base apparently destabilized the entire arcade, including its cool-plasma-carrying core field, to undergo a blowout eruption in the manner of many standard-sized, arcade-blowout eruptions that produce a flare and coronal mass ejection. Internal reconnection made bright 'flare' loops over the polarity inversion line inside the blowing-out arcade field, and external reconnection of the blowing-out arcade field with an ambient open field made longer and dimmer EUV loops on the outside of the blowing-out arcade. That the loops made by the external reconnection were much larger than the loops made by the internal reconnection makes this event a new variety of blowout jet, a variety not recognized in previous observations and models of blowout jets.

  10. Clinical usefulness of helical CT three-dimensional images in blow-out fractures

    International Nuclear Information System (INIS)

    Since the bone of the orbital floor is very thin, it was previously impossible to visualize bone deficits and bone fracture lines of the orbital floor accurately in three-dimensional (3D) CT images. Since the analytical ability of CT and 3D image reconstitution have improved, however, CT imaging of thin bone has become possible. We used CT photography and 3D image reconstruction in 19 cases before surgery to correct blow-out fracture. We used the Toshiba Corporation helical CT system (X-Vigor, version 5.0A) and filmed an area 3-4 cm wide in the orbital region, mainly on the orbital floor. The X-Tension workstation (Toshiba) was used for 3D image reconstruction. All cases were filmed in 0.5-mm slices. CT scanning time was approximately 60 seconds. There were very few artifacts in the 3D images. Small bone deficits and minute bone fracture lines could be observed on the 3D images, and it was also possible to change the visual angle. The CT images were faithful, their reliability was good, and they were clinically useful. In 8 cases in which a silicon sheet was used for reconstruction of the orbital floor, 3D images were also used for postoperative evaluation. The silicon sheets used to reconstruct bone deficits could be selectively viewed on the image and their condition determined 3D CT images are therefore considered useful in both pre- and postoperative evaluation of blow-out fractures. We have utilized these 3D CT images in the evaluation of zygomatic bone and other facial fractures in addition to blow-out fractures. (author)

  11. The rise and fall of methanotrophy following a deepwater oil-well blowout

    OpenAIRE

    Crespo-Medina, M.; Meile, C.D.; Hunter, K. S.; Diercks, A. R.; Asper, V.; V. J. Orphan; Tavormina, P L; Nigro, L. M.; Battles, J. J.; Chanton, J.P.; Shiller, A. M.; Joung, D-J.; Amon, R.M.W.; Bracco, A.; Montoya, J. P.

    2014-01-01

    The blowout of the Macondo oil well in the Gulf of Mexico in April 2010 injected up to 500,000 tonnes of natural gas, mainly methane, into the deep sea1. Most of the methane released was thought to have been consumed by marine microbes between July and August 20102, 3. Here, we report spatially extensive measurements of methane concentrations and oxidation rates in the nine months following the spill. We show that although gas-rich deepwater plumes were a short-lived feature, water column con...

  12. Investigating the dynamics of combustion-driven oscillations leading to lean blowout

    International Nuclear Information System (INIS)

    The dynamics of combustion-driven thermoacoustic oscillations for a ducted laminar premixed flame has been investigated in lean equivalence ratio conditions. Combustion instability appears in the system as acoustic pressure and flame surface oscillations following a Hopf bifurcation. Further change in the control parameter leads to subsequent bifurcations, causing a rich dynamical behavior such as quasi-periodic and intermittent burst oscillations to appear in the system. During the burst oscillation phase, the system dynamics resembles the flame blowout phenomenon, which is of interest in practical combustion applications. (paper)

  13. Footprint of Deepwater Horizon blowout impact to deep-water coral communities

    OpenAIRE

    Fisher, Charles R.; Hsing, Pen-Yuan; Kaiser, Carl L.; Yoerger, Dana R.; Roberts, Harry H.; Shedd, William W.; Cordes, Erik E.; Shank, Timothy M.; Berlet, Samantha P.; Saunders, Miles G.; Larcom, Elizabeth A.; Brooks, James M.

    2014-01-01

    The Deepwater Horizon blowout released more oil and gas into the deep sea than any previous spill. Soon after the well was capped, a deep-sea community 13 km southwest of the wellhead was discovered with corals that had been damaged by the spill. Here we show this was not an isolated incident; at least two other coral communities were also impacted by the spill. One was almost twice as far from the wellhead and in 50% deeper water, considerably expanding the known area of impact. In addition,...

  14. 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.

  15. Reliability Analysis of the Electrical Control System of Subsea Blowout Preventers Using Markov Models

    Science.gov (United States)

    Liu, Zengkai; Liu, Yonghong; Cai, Baoping

    2014-01-01

    Reliability analysis of the electrical control system of a subsea blowout preventer (BOP) stack is carried out based on Markov method. For the subsea BOP electrical control system used in the current work, the 3-2-1-0 and 3-2-0 input voting schemes are available. The effects of the voting schemes on system performance are evaluated based on Markov models. In addition, the effects of failure rates of the modules and repair time on system reliability indices are also investigated. PMID:25409010

  16. Numerical simulations of the Macondo well blowout reveal strong control of oil flow by reservoir permeability and exsolution of gas

    OpenAIRE

    Oldenburg, Curtis M.; Freifeld, Barry M.; Pruess, Karsten; Pan, Lehua; Finsterle, Stefan; Moridis, George J.

    2011-01-01

    In response to the urgent need for estimates of the oil and gas flow rate from the Macondo well MC252-1 blowout, we assembled a small team and carried out oil and gas flow simulations using the TOUGH2 codes over two weeks in mid-2010. The conceptual model included the oil reservoir and the well with a top boundary condition located at the bottom of the blowout preventer. We developed a fluid properties module (Eoil) applicable to a simple two-phase and two-component oil-gas system. The flow o...

  17. 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.

  18. Impacts of an oil well blowout near Trecate, Italy on ecological resources

    International Nuclear Information System (INIS)

    An ecological risk assessment (ERA) was conducted after the February 1995 blowout of an oil well near Trecate, Italy to quantify injuries to terrestrial and aquatic biological resources from effects of oil and habitat changes. Avian surveys were conducted on a surrogate area near Varallino to estimate species and numbers potentially exposed to oil and displaced by habitat alteration in the affected area. Of the 43 avian species observed, 20 are considered protected by European Community laws. The most abundant species were passero domestico, fringuello, cornacchia grigia, rondine, piccione torraiolo, and cardellino. These species likely suffered the greatest losses due to inhalation of volatile aromatics, dermal loading of oil, and/or habitat loss in the affected area. Based on CHARM model outputs, inhalation exposures to volatile aromatics and oil aerosols occurred above LOELs for all receptors within 2 km of the blowout. The most significant exposure pathway to large birds was dermal loading, which likely exceeded LC50 levels within 900m of the well. Terrestrial insects seldom contained detectable levels of PAHs, consistent with their shorter life span and residence time in the contaminated area. The highest concentrations of PAHs were found in dike vegetation, frogs, and benthic invertebrates. Ingestion exposures of woodmice to PAHs exceeded toxic reference levels at one site and mice had EHQ = >1 at soil PAH concentrations >4.2 mg/kg. Based on known body burdens causing narcotic response, neither fish nor benthic invertebrates experienced toxic consequences from exposure to PAHs in irrigation canal sediments

  19. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Jason P. Wilke

    2005-09-30

    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.

  1. Findings of a retrospective survey conducted after the Lodgepole sour gas well blowout to determine if the natural occurrence of bovine abortions and fetal anomalies increased

    International Nuclear Information System (INIS)

    A survey was conducted after the Lodgepole sour gas well blowout of October 1982 to determine if the incident changed the number and type of bovine abortions and abnormal bovine feti submitted to the diagnostic laboratory from the blowout area. The records of the total number of bovine feti submitted were compared between three areas to determine if there was a significant difference between the areas closer to the well site and the larger total area. No changes or trends could be ascribed to the well blowout. 2 refs., 5 tabs

  2. 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.

  3. Correlation between orbital volume on CT and enophthalmos in blow-out fracture

    International Nuclear Information System (INIS)

    Objective: To explore the evolution of orbital volume on CT and enophthalmos in patients with blow-out fracture, to study the relationship between orbital volume change and degree of enophthalmos, and to compare the accuracies of CT and Hertel in evaluating the degree of the enophthalmos. Methods: 40 patients with unilateral blow-out fracture of single eye were selected and divided into early stage group (22 cases, within three days, without enophthalmos) and late stage group (18 cases, over two weeks, with enophthalmos). In early stage group, the orbital volumes were measured with CT. The time and degree of enophthalmos were observed in the first second and third week after injury. In late stage group, the orbital volumes were measured with CT. The degree of enophthalmos was measured with both Hertel exophthalmometer and CT. All measurements were using their normal orbital as controls. Statistic analysis was carried out with SPSS 17.0, including the paired t test, Chi-square test, correlation analysis and linear regression. Results: 1 The orbital volumes of 40 patients with blow-out fracture were significantly increased comparing with those of normal controls. 2 In the early stage group, there were significant differences in presence of enophthalmos between the first week and the other two weeks. 3 In the early stage group, the orbital volumes were not significantly different among the three time points. 4 There was significant linear correlation between the enlargement of orbital volume and the degree of enophthalmos. The linear regression equation of enophthalmos (y) and the enlargement orbital volume (x) was: y=0.057+0.829x (P<0.01), with each 1.0 cm3 enlargement in the orbital volume causing approximately 0.886 mm enophthalmos. 5 In the later stage group, the degree of the enophthalmos measured on CT was significantly higher than that of Hertel in (1.53±0.73 mm). Conclusions: 1 Enophthalmos usually appears after the second week of injury. 2 The edema of

  4. Environmental implications of a gas well blowout in northwest Louisiana - A case study

    International Nuclear Information System (INIS)

    Oil and gas exploration in northern Louisiana has been ongoing since the 1920s. During this time occasional blowouts have occurred which have impacted the environment. In March, 1994, a Sligo Field well experienced an unusual blowout in that the event propagated to the surface through an adjacent abandoned well. While drilling through the fractured Thompson-Pettet interval at a depth of 5000 feet, a pressure kick, caused by a loss of drilling fluids, occurred. The well control devices activated and prevented loss of the well. However, the pressure front moved up the well's uncased annulus until reaching the base of the cemented surface casing where it dispersed laterally in the Nacatoch formation at a depth of approximately 1000 feet. This was the uppermost portion of the uncased hole. The pressure front propagated through the Nacatoch until it encountered the poorly cemented annulus of the abandoned Hardman No. 1 well, located approximately 300 feet to the south of the drilling location. After moving up the annulus of the Hardman No. 1 well and charging the fresh water sands of the Wilcox system, local residential water wells and the drilling rig's water supply well became flowing artesian. Several hours later sand and fluids began erupting, creating a large cavity on the outside of the casing surrounding the Hardman No. 1 well. The artesian impact lasted approximately four days until the pressure front dissipated. Subsequent sampling of the rig supply well determined the well to be contaminated with benzene, a known human carcinogen. The Louisiana Department of Environmental Quality, in conjunction with the operator, is currently investigating the extent of contamination with the goal of ensuring the health of the local residents and the protection of the environment

  5. Study of slagging in and blowout of P-59 boiler furnace screens during the burning of Moscow-area coal

    Energy Technology Data Exchange (ETDEWEB)

    Guzenko, S.I.; Vasil' ev, V.V.; Serebryanikov, N.I.; Panchenko, V.F.; Meelak, Kh.O.; Khaikin, I.B.; Perevezentsev, V.P.

    1978-03-01

    The operation of the burners of the P-59 boilers at the Ryazan GRES, burning Moscow area brown coal, is characterized by intense slagging of the LRP screens, especially in the zone of maximum heat formation, causing a particularly severe screen cleaning problem. The thermal efficiency of screen cleaning by steam blowout using OM-0.35 devices is low even with intense use (every 2 hours), which is accompanied by dangerous steam-ash erosion of the tubes. Water blowout of the LRP (lower radiative part) of the P-59 boiler with four long-range M-3A devices is rather effective. Under conditions of intense formation of deposits on the screens of the lower radiative part of P-59 boilers they cannot be brought up to an operationally clean state using known cleaning methods.

  6. Survey of Common Practices among Oculofacial Surgeons in the Asia-Pacific Region: Management of Orbital Floor Blowout Fractures

    OpenAIRE

    Koh, Victor; Chiam, Nathalie; Sundar, Gangadhara

    2014-01-01

    A web-based anonymous survey was performed to assess common practices of oculofacial surgeons in the management of traumatic orbital floor blowout fractures. A questionnaire which contained questions on several controversial topics in the management of orbital floor fractures was sent out via e-mail to 131 oculofacial surgeons in 14 countries in the Asia-Pacific region. A total response rate of 58.3% was achieved from May to December 2012. The preferred time for surgical intervention was with...

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

    OpenAIRE

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

    2012-01-01

    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. Evaluat...

  8. Field investigation finding of long term effects in Alberta livestock exposed to acid forming emissions: Survey following the Lodgepole blowout

    International Nuclear Information System (INIS)

    The effects of the Amoco Dome Brazeau River (Lodgepole) sour gas well blowout of October 1982 on livestock are reviewed. For 26 days the well was not on fire, with condensate falling on the area immediately surrounding the well site, while during the 41 days the well was burning, sour gas and condensate underwent combustion in the intense fire. Many local residents noted problems with their farm animals during the blowout period. A study was undertaken to evaluate opinions and attitudes of livestock producers about the long-term effects of the Lodgepole blowout. Contact was made with producers in the area of concern, and a worksheet was developed to aid in the collection of data. Information gathered was based on producer records, auction sale tickets, sales receipts and memory. Twenty livestock producers were interviewed, representing 1,700 head of beef cows, 40 dairy cows and 21 sows. Concerns expressed by producers included birth weight, birth defects or stillbirth, scours and problem calves, poor growth, open or dry cows, abortions, late calves, poor growth in replacement heifers, abnormal hair, and abnormal breeding. 1 tab

  9. 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...

  10. 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.

  11. 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

  12. Trigger of a blowout jet in a solar coronal mass ejection associated with a flare

    CERN Document Server

    Li, Xiaohong; Chen, Huadong; Li, Ting; Zhang, Jun

    2015-01-01

    Using the multi-wavelength images and the photospheric magnetograms from the \\emph{Solar Dynamics Observatory}, we study the flare which was associated by the only one coronal mass ejection (CME) in active region (AR) 12192. The eruption of a filament caused a blowout jet, and then an M4.0 class flare occurred. This flare was located at the edge of AR instead of in the core region. The flare was close to the apparently "open" fields, appearing as extreme-ultraviolet structures that fan out rapidly. Due to the interaction between flare materials and "open" fields, the flare became an eruptive flare, leading to the CME. Then at the same site of the first eruption, another small filament erupted. With the high spatial and temporal resolution H$\\alpha$ data from the New Vacuum Solar Telescope at the \\emph{Fuxian Solar Observatory}, we investigate the interaction between the second filament and the nearby "open" lines. The filament reconnected with the "open" lines, forming a new system. To our knowledge, the deta...

  13. Numerical simulations of the Macondo well blowout reveal strong control of oil flow by reservoir permeability and exsolution of gas.

    Science.gov (United States)

    Oldenburg, Curtis M; Freifeld, Barry M; Pruess, Karsten; Pan, Lehua; Finsterle, Stefan; Moridis, George J

    2012-12-11

    In response to the urgent need for estimates of the oil and gas flow rate from the Macondo well MC252-1 blowout, we assembled a small team and carried out oil and gas flow simulations using the TOUGH2 codes over two weeks in mid-2010. The conceptual model included the oil reservoir and the well with a top boundary condition located at the bottom of the blowout preventer. We developed a fluid properties module (Eoil) applicable to a simple two-phase and two-component oil-gas system. The flow of oil and gas was simulated using T2Well, a coupled reservoir-wellbore flow model, along with iTOUGH2 for sensitivity analysis and uncertainty quantification. The most likely oil flow rate estimated from simulations based on the data available in early June 2010 was about 100,000 bbl/d (barrels per day) with a corresponding gas flow rate of 300 MMscf/d (million standard cubic feet per day) assuming the well was open to the reservoir over 30 m of thickness. A Monte Carlo analysis of reservoir and fluid properties provided an uncertainty distribution with a long tail extending down to 60,000 bbl/d of oil (170 MMscf/d of gas). The flow rate was most strongly sensitive to reservoir permeability. Conceptual model uncertainty was also significant, particularly with regard to the length of the well that was open to the reservoir. For fluid-entry interval length of 1.5 m, the oil flow rate was about 56,000 bbl/d. Sensitivity analyses showed that flow rate was not very sensitive to pressure-drop across the blowout preventer due to the interplay between gas exsolution and oil flow rate. PMID:21730177

  14. Dynamic study of ocular movement with MR imaging in orbital blow-out fracture

    International Nuclear Information System (INIS)

    Operative indications for orbital blow-out fracture (OBF) remain controversial. One of the major sources of this controversy is that an accurate diagnosis of ocular movement disturbances can not be made by conventional procedures such as the Hess screen test, traction test, or CT scan. Disturbances in ocular movement resulting from OBF can occur not only with entrapment of the extraocular muscle but also with intraorbital bleeding, edema, and/or a variety of other unclear factors. To obtain a more accurate diagnosis and to assist in the choice of treatment, ocular movement was examined using orbital 'cine mode' MR imaging. MR images were obtained in multiple phases of vertical and horizontal ocular movements by using the 'fast SE' capabilities of the SIERRA, GE-YMS MR scanner (1.5 Tesla, superconductive). The fixed eye method was applied to two normal volunteers and to patients with 'pure' OBF. Five marks for binocular fixation were affixed to the inner wall of the gantry: one at the primary position and four at secondary positions. While keeping the subject's eye focused on each of these marks for about 30 sec, MR images (head coil) of the axial view and bilateral oblique sagittal view along the optic nerve were carried out. In the normal volunteers, a good demonstration of smooth movement of the eye ball, extraocular muscles, and the optic nerve could be obtained. In the OBF patients, it was clearly observed that the disturbance in ocular movement was caused by poor extension of the external ocular muscles, specifically the inferior rectus muscle in the orbital floor fracture, and the internal rectus muscle in the medial wall fracture. These observations suggested that dynamic orbital imaging with MR would be extremely valuable in the assessment of disturbances of ocular movement in OBF. (author)

  15. Endovascular therapeutic occlusion following bilateral carotid artery bypass for radiation-induced carotid artery blowout. Case report

    International Nuclear Information System (INIS)

    A patients with breast cancer received radiation therapy to the upper chest wall. Twenty-two years later, she presented with repeated severe bleeding through a left lower neck ulcer. She was taken to surgery for hemostasis, which was not successful because the carotid artery was surgically inaccessible. To manage for explosive carotid blowout, we performed common carotid artery ligation and endovascular coil embolization after contralateral-external-carotid to ipsilateral-common-carotid artery bypass with a polytetrafluoroethylene (PTFE) graft. The patients has experienced no ischemic events or bleeding since this treatment. (author)

  16. 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

  17. Survey of Common Practices among Oculofacial Surgeons in the Asia-Pacific Region: Management of Orbital Floor Blowout Fractures.

    Science.gov (United States)

    Koh, Victor; Chiam, Nathalie; Sundar, Gangadhara

    2014-09-01

    A web-based anonymous survey was performed to assess common practices of oculofacial surgeons in the management of traumatic orbital floor blowout fractures. A questionnaire which contained questions on several controversial topics in the management of orbital floor fractures was sent out via e-mail to 131 oculofacial surgeons in 14 countries in the Asia-Pacific region. A total response rate of 58.3% was achieved from May to December 2012. The preferred time for surgical intervention was within 2 weeks for adult patients, porous polyethylene implant was the most popular choice, and most surgeons preferred the transconjunctival approach. Postoperatively, diplopia was the most commonly encountered complication and most oculofacial surgeons reviewed their patients regularly for up to 12 months. We report the results of the first survey of oculofacial surgeons within the Asia-Pacific region on the management of orbital floor blowout fractures. Compared with previous surveys (from year 2000 to 2004), the duration to surgical intervention was comparable but there was a contrasting change in preferred surgical approach and choice of orbital implant. PMID:25136408

  18. Endovascular treatment of radiation-induced carotid blowout syndrome. Report of two cases

    International Nuclear Information System (INIS)

    Carotid Blowout Syndrome (CBS), or Carotid Artery Rupture (CAR), is a delayed complication with potentially fatal consequences occurring after the implementation of radiotherapy on head and neck tumors. In this report we describe two patients received endovascular treatment for severe hemorrhagic CBS developing 36 and 2 years, respectively, after radiotherapy. Both patients survived and responded positively to treatment. Case 1 was an 80-year-old woman found with minor hemorrhage near the bifurcation of the common carotid artery, 36 years after neck irradiation. She experienced frequent hemorrhagic events during the following years. Six years after the initial discovery of bleeding, she experienced massive hemorrhage, lapsed into shock, and was admitted to an Emergency Room. Connective tissue around the carotid artery was largely exposed due to neck skin defect. After hemorrhage was halted by manual compression, transient hemostasis was achieved with coil embolization of the aneurysm presumed to be the source of bleeding. Recurrent hemorrhage developed two weeks later with unraveled coil mass extrusion. Parent artery occlusion was performed by endovascular trapping, achieving permanent hemostasis. Case 2 presented massive nasal bleeding originating from the petrous segment of the internal carotid artery, 2 years after having been treated with heavy particle irradiation for olfactory neuroblastoma. Ischemic tolerance was confirmed by balloon occlusion test. Based on previous experiences, the bleeding was immediately halted by endovascular trapping. Both patients were subsequently discharged, free of new neurological symptoms. Emergent hemostatic treatment is required in CBS developing severe hemorrhage. However, within irradiation fields, temporal embolization devices hardly lead to complete resolution. This is due to the deteriorated condition of the vascular wall incapable to enduring the expansion power of coils, stents or balloons. Bypass grafting is also

  19. 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.

  20. 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)

    Jason P. Wilke

    2005-09-30

    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.

  1. 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

  2. Real-Time Control of Lean Blowout in a Turbine Engine for Minimizing No(x) Emissions

    Science.gov (United States)

    Zinn, Ben

    2004-01-01

    This report describes research on the development and demonstration of a controlled combustor operates with minimal NO, emissions, thus meeting one of NASA s UEET program goals. NO(x) emissions have been successfully minimized by operating a premixed, lean burning combustor (modeling a lean prevaporized, premixed LPP combustor) safely near its lean blowout (LBO) limit over a range of operating conditions. This was accomplished by integrating the combustor with an LBO precursor sensor and closed-loop, rule-based control system that allowed the combustor to operate far closer to the point of LBO than an uncontrolled combustor would be allowed to in a current engine. Since leaner operation generally leads to lower NO, emissions, engine NO, was reduced without loss of safety.

  3. Fibrillar Chromospheric Spicule-Like Counterparts to an EUV and Soft X-Ray Blowout Coronal Jet

    Science.gov (United States)

    Sterling, Alphonse C.; Harra, Louise K.; Moore, Ronald L.

    2010-01-01

    We observe an erupting jet feature in a solar polar coronal hole, using data from Hinode/SOT, EIS, and XRT, with supplemental data from STEREO/EUVI. From EUV and soft X-ray (SXR) images we identify the erupting feature as a blowout coronal jet: in SXRs it is a jet with bright base, and in EUV it appears as an eruption of relatively cool (approximately 50,000 K) material of horizontal size scale approximately 30" originating from the base of the SXR jet. In SOT Ca II H images the most pronounced analog is a pair of thin (approximately 1") ejections, at the locations of either of the two legs of the erupting EUV jet. These Ca II features eventually rise beyond 45", leaving the SOT field of view, and have an appearance similar to standard spicules except that they are much taller. They have velocities similar to that of "type II" spicules, approximately 100 kilometers per second, and they appear to have spicule-like substructures splitting off from them with horizontal velocity approximately 50 kilometers per second, similar to the velocities of splitting spicules measured by Sterling et al. (2010). Motions of splitting features and of other substructures suggest that the macroscopic EUV jet is spinning or unwinding as it is ejected. This and earlier work suggests that a sub-population of Ca II type II spicules are the Ca II manifestation of portions of larger-scale erupting magnetic jets. A different sub-population of type II spicules could be blowout jets occurring on a much smaller horizontal size scale than the event we observe here.

  4. A peculiar blow-out fracture of the inferior orbital wall complicated by extensive subcutaneous emphysema: A case report and review of the literature

    International Nuclear Information System (INIS)

    Blow-out fracture of the orbit is a common injury. However, not many cases are associated with massive subcutaneous emphysema. Even fewer cases are caused by minor trauma or are associated with barotrauma to the orbit due to sneezing, coughing, or vomiting. The authors present a case of blow-out fracture complicated by extensive subcutaneous and mediastinal emphysema that occurred without any obvious traumatic event. A 43-year-old man presented to the Emergency Department with a painful right-sided exophthalmos that he had noticed in the morning immediately after waking up. The patient also complained of diplopia. Physical examination revealed exophthalmos and crepitations suggestive of subcutaneous emphysema. The eye movements, especially upward gaze, were impaired. CT showed blow-out fracture of the inferior orbital wall with a herniation of the orbital soft tissues into the maxillary sinus. There was an extensive subcutaneous emphysema in the head and neck going down to the mediastinum. The patient did not remember any significant trauma to the head that could explain the above mentioned findings. At surgery, an inferior orbital wall fracture with a bony defect of 3×2 centimeter was found and repaired. Blow-out fractures of the orbit are usually a result of a direct trauma caused by an object with a diameter exceeding the bony margins of the orbit. In 50% of cases, they are complicated by orbital emphysema and in 4% of cases by herniation of orbital soft tissues into paranasal sinuses. The occurrence of orbital emphysema without trauma is unusual. In some cases it seems to be related to barotrauma due to a rapid increase in pressure in the upper airways during sneezing, coughing, or vomiting, which very rarely leads to orbital wall fracture. Computed tomography is the most accurate method in detecting and assessing the extent of orbital wall fractures

  5. Application of fine managed pressure drilling technique in complex wells with both blowout and lost circulation risks

    Directory of Open Access Journals (Sweden)

    Ling Yan

    2015-03-01

    Full Text Available Fractured carbonate reservoirs are susceptible to blowout and lost circulation during drilling, which not only restricts drilling speed, but also poses big threat to well control. Moreover, there are few technical means available to reconstruct pressure balance in the borehole. Accordingly, the fine managed pressure drilling was used in the drilling of Well GS19 in the Qixia Formation with super-high pressure and narrow density window, which is a success: ① back pressure in the annular spaces will be adjusted to maintain a slightly over-balanced bottom-hole hydraulic pressure, and fluid level in the circulation tank will be kept in a slight dropping state to ensure that natural gas in the formation would not invade into the borehole in a massive volume; ② inlet drilling fluid density will be controlled at around 2.35 g/cm3, back pressures in the annular be maintained at 2–5 MPa, and bottom-hole pressure equivalent circulation density be controlled at 2.46–2.52 g/cm3; ③ during managed pressure drilling operations, if wellhead pressure exceeds or expects to exceed 7 MPa, semi-blind rams will be closed. Fluids will pass through the choke manifold of the rig to the choke manifold specifically for pressure control before entering gas/liquid separators to discharge gas; ④ during tripping back pressure will be kept at less than 5 MPa, volume of injected drilling fluid will be higher than the theoretical volume during tripping out, whereas the volume of returned drilling fluid will be higher than the theoretical volume during the out-tripping. This technique has been applied successfully in the drilling of the Qixia Formation, Liangshan Formation and Longmaxi Formation with a total footage of 216.60 m, as a good attempt in complicated wells with both blowout and lost circulation risks, which can provide valuable experiences and guidance for handling similar complexities in the future.

  6. 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. PMID:23213217

  7. Geomorphological and ecological features of blowouts in a western Mediterranean coastal dune complex: a case study of the Es Comú de Muro beach-dune system on the island of Mallorca, Spain

    Science.gov (United States)

    Mir-Gual, Miquel; Pons, Guillem X.; Martín-Prieto, José Ángel; Roig-Munar, Francesc X.; Rodríguez-Perea, Antonio

    2013-04-01

    Many of the coastal dune systems along western Mediterranean shores are in an advanced state of fragmentation and show distinct signs of erosion, largely because of blowout development along the dune front. The Es Comú de Muro beach-dune system on the island of Mallorca (Spain) is a good example of this. In order to better understand and quantify the current situation, 58 blowouts along a ca. 1.5-km-long dune front were investigated. In each case, a number of morphometric and ecological variables were analyzed as a basis for comparison and classification, in particular blowout dimensions and orientation, inner morphometry and topography, morphological types, the role of vegetation in defining the state of the foremost dune line, and the link between vegetation and blowout typology. In comparison with a recent preliminary investigation, the results of the present study provide a more comprehensive picture of the advanced state of fragmentation along the dune front. The blowouts are not evenly distributed, highest densities occurring along the southernmost part of the beach, lowest densities along the northern part. The blowouts were subdivided into two categories on the basis of their shape and general structure, trough blowouts being the most prevalent, followed by mixed trough-saucer shapes. Distinctly saucer-shaped blowouts could not be distinguished. In addition, the blowouts were subdivided into two morphological categories, i.e. simple and branched. It was also possible to link the morphological state of the dune front to certain ecological parameters, in particular vegetation which, in the present case, comprised herbaceous and woody plants. Cluster analyses of species associations (Bray-Curtis similarity indices) were carried out on the basis of the presence/absence of each species. It is shown that, on account of presence counts and the degree of similarity of species associations, some species play a more important role in stabilizing the mobile dune

  8. Delayed Development of Brain Abscesses Following Stent-Graft Placement in a Head and Neck Cancer Patient Presenting with Carotid Blowout Syndrome

    International Nuclear Information System (INIS)

    We describe the delayed development of intracranial abscesses following emergent treatment with a covered stent-graft for carotid blowout syndrome (CBS) in a patient with head and neck cancer. The patient presented with hemoptysis and frank arterial bleeding through the tracheostomy site. A self-expandable stent-graft was deployed across a small pseudoaneurysm arising from the right common carotid artery (RCCA) and resulted in immediate hemostasis. Three months later, the patient suffered a recurrent hemorrhage. CT of the neck demonstrated periluminal fluid around the caudal aspect of the stent-graft with intraluminal thrombus and a small pseudoaneurysm. Subsequently, the patient underwent a balloon test occlusion study and endovascular sacrifice of the RCCA and right internal carotid artery. MRI of the brain demonstrated at least four ring-enhancing lesions within the right cerebral hemisphere consistent with intracranial abscesses that resolved with broad-spectrum antibiotic coverage.

  9. Characteristics of lean blowout limit for backward step-stabilized flame with centrifugal force effect%离心条件下后台阶贫油熄火特性

    Institute of Scientific and Technical Information of China (English)

    李林; 林宇震; 郭新华; 孙强

    2011-01-01

    Using the centrifugal force effect of a whirl flow through a curved pipe to simulate the working conditions in the rotor combustion system, this thesis investigated the effect of the geometric parameters on lean blowout limit of spray combustion for the backward step flame holder. On the basis of a curved flow channel experiment rig, a backward step flame holder was designed with variable geometric parameters. The geometric parameters include: the height, length and distance between backward step and wall surface. The effect of these three geometric parameters on the lean blowout limit of spray combustion was investigated. Test results indicate that, the height and length have great effect on flame blowout limit. With the increase of the height and length, the lean blowout limit decreases;but the distance between backward step and wall surface has little effect on flame blowout limit. For each backward step flame holder, while centrifugal force effect increases, the flame lean blowout limit is reduced and flameout range is broadened. This research work has laid a foundation for investigation of spray combustion on the rotor combustion system.%利用气流通过弯管产生的离心效应来模拟高速旋转的工况,研究高位后台阶火焰稳定器的关键几何参数对液雾燃烧贫油熄火特性的影响.通过控制后台阶高度,台阶板长度,后台阶到上壁面的距离三个几何参数,考察它们对后台阶火焰稳定器贫油熄火特性的影响.试验得到的结果表明在离心条件下,后台阶高度和台阶板长度对贫油熄火特性的影响较大,随着后台阶高度和台阶板长度的增加,贫油熄火极限降低,范围拓宽;而后台阶到上壁面的距离对贫油熄火特性影响很小;对于同一个后台阶而言,随着离心力的增加,后台阶火焰稳定器的贫油熄火极限也降低,熄火范围拓宽.

  10. Forensic epidemiologic and biomechanical analysis of a pelvic cavity blowout injury associated with ejection from a personal watercraft (jet-ski).

    Science.gov (United States)

    Freeman, Michael D; Everson, Todd M; Kohles, Sean S

    2013-01-01

    Jet-propelled personal watercraft (PWC) or jet-skis have become increasingly popular. The means of propulsion of PWC, which is a jet of water forced out of small nozzle at the rear of the craft, combined with a high risk of falling off of the seat and into close proximity with the water jet stream, raise the potential for a unique type of injury mechanism. The most serious injuries associated with PWC falls are those that occur when the perineum passes in close proximity to the jet nozzle and the high-pressure water stream enters the vaginal or rectal orifice. We describe the forensic investigation into a case of an anovaginal "blowout" injury in a passenger who was ejected from the rear seat position of a PWC and subsequently suffered life-threatening injuries to the pelvic organs. The investigation included a biomechanical analysis of the injury mechanism, a summary of prior published reports of internal pelvic injuries resulting from PWC falls as well as other water sports and activities, and a comparison of the severity of the injuries resulting from differing mechanisms using the New Injury Severity Score (NISS). The mean (± standard deviation [SD]) NISS values for reported PWC injuries [not including the NISS of 38 in this case study] were 11.2 (± 9.5), while the mean value for reported water-skiing falls was half that of the PWC group at 5.6 (± 5.2). It was concluded that the analyzed injuries were unique to a PWC ejection versus other previously described non-PWC-associated water sport injuries. It is recommended that PWC manufacturers help consumers understand the potential risks to passengers with highly visible warnings and reduce injury risk with revised seat design, and/or passenger seat "deadman" switches. PMID:22925030

  11. Evaluation of the outcomes of endovascular management for patients with head and neck cancers and associated carotid blowout syndrome of the external carotid artery

    International Nuclear Information System (INIS)

    Aim: To evaluate factors related to the technical and haemostatic outcomes of endovascular management in patients with head and neck cancers (HNC) associated with carotid blowout syndrome (CBS) of the external carotid artery (ECA). Materials and methods: Between 2002 and 2011, 34 patients with HNC with CBS involving branches of the ECA underwent endovascular therapy. Treatment included embolization with microparticles, microcoils, or acrylic adhesives. Fisher's exact test was used to examine demographic features, clinical and angiographic severities, and clinical and imaging findings as predictors of endovascular management outcomes. Results: Technical success and immediate haemostasis were achieved in all patients. Technical complications were encountered in one patient (2.9%). Rebleeding occurred in nine patients (26.5%). Angiographic vascular disruption grading from slight (1) to severe (4) revealed that the 18 patients with acute CBS had scores of 2 (2/18, 11.1%), 3 (3/18, 16.7%), and 4 (13/18, 72.2%). The 16 patients with impending and threatened CBS had scores of 1 (1/16, 6.25%), 2 (5/16, 31.25%), and 3 (10/16, 62.5%; p = 0.0003). For the 25 patients who underwent preprocedural computed tomography (CT)/magnetic resonance imaging (MRI) examinations within 3 months of treatment, the agreement between clinical and imaging findings reached the sensitivity, specificity, and kappa values for recurrent tumours (1, 0.7143, 0.7826), soft-tissue defect (0.9091, 0.3333, 0.2424), and sinus tract/fistula (0.4737, 0, 0.4286). Conclusion: Endovascular management for patients with CBS of the ECA had high technical success and safety but was associated with high rebleeding rates. We suggest applying aggressive post-procedural follow-up and using preprocedural CT/MRI to enhance the periprocedural diagnosis

  12. Carotid blowout syndrome in pharyngeal cancer patients treated by hypofractionated stereotactic re-irradiation using CyberKnife: A multi-institutional matched-cohort analysis

    International Nuclear Information System (INIS)

    Background and purpose: Although reirradiation has attracted attention as a potential therapy for recurrent head and neck tumors with the advent of modern radiotherapy, severe rate toxicity such as carotid blowout syndrome (CBOS) limits its potential. The aim of this study was to identify the risk factors of CBOS after hypofractionated stereotactic radiotherapy (SBRT). Methods and patients: We conducted a matched-pair design examination of pharyngeal cancer patients treated by CyberKnife reirradiation in four institutes. Twelve cases with CBOS were observed per 60 cases without CBOS cases. Prognostic factors for CBOS were analyzed and a risk classification model was constructed. Results: The median prescribed radiation dose was 30 Gy in 5 fractions with CyberKnife SBRT after 60 Gy/30 fractions of previous radiotherapy. The median duration between reirradiation and CBOS onset was 5 months (range, 0–69 months). CBOS cases showed a median survival time of 5.5 months compared to 22.8 months for non-CBOS cases (1-year survival rate, 36% vs.72%; p = 0.003). Univariate analysis identified an angle of carotid invasion of >180°, the presence of ulceration, planning treatment volume, and irradiation to lymph node areas as statistically significant predisposing factors for CBOS. Only patients with carotid invasion of >180° developed CBOS (12/50, 24%), whereas no patient with tumor involvement less than a half semicircle around the carotid artery developed CBOS (0/22, 0%, p = 0.03). Multivariate Cox hazard model analysis revealed that the presence of ulceration and irradiation to lymph nodes were statistically significant predisposing factors. Thus, we constructed a CBOS risk classification system: CBOS index = (summation of risk factors; carotid invasion >180°, presence of ulceration, lymph node area irradiation). This system sufficiently separated the risk groups. Conclusion: The presence of ulceration and lymph node irradiation are risk factors of CBOS. The CBOS index

  13. 基于模糊故障树方法的钻井平台井喷概率计算%Probability Calculation of Blowout of Drilling Platform Based on Fuzzy Fault Tree Method

    Institute of Scientific and Technical Information of China (English)

    董海波; 顾学康

    2013-01-01

      基于模糊理论,提出了一种定量风险评估方法——模糊故障树方法。查阅历史数据库或者借助专家判断,给出故障树模型中各基本事件发生可能性的模糊数表示。考虑到不同专家意见之间可能存在的差异,给出了处理专家意见的运算法则及确定专家权重的理论方法。以半潜式钻井平台发生井喷为顶事件,构建了故障树模型,依据给出的模糊故障树理论模型,计算得到半潜式平台在钻进或固井过程中发生井喷的概率。%Based on fuzzy theory, a quantitative risk assessment method called fuzzy fault tree analysis is presented. By referring to risk database or by dint of expert judgements, this paper presents occurrence possibility of each basic event in the fault tree model which is expressed in the form of fuzzy numbers. Since each expert may have a different opinion, this paper developes an algorithm to aggregate expert opinion and a method to determine the importance weight of expert opinion. This paper constructs fault tree model on blowout of semi-submersible drilling platform. According to fuzzy fault tree analysis method, the probability of blowout is calculated during drilling or cementing on a semi-submersible drilling platform.

  14. 特大井喷H_2S扩散的数值模拟分析%Numerical simulation analysis of H_2S diffusion in a catastrophic gas blowout accident: A case study of Kai

    Institute of Scientific and Technical Information of China (English)

    练章华; 周兆明; 王辉; 李孝军; 林铁军

    2009-01-01

    含H_2S气体的高压井喷是一个非常复杂的扩散问题,涉及多组分气体的混合、运移、扩散、气象条件以及复杂的地形空间影响.为此,采用可行的计算流体动力学(CFD)对这一复杂的大空间流场问题进行了数值模拟研究,根据重庆开县特大井喷事故现场三维地貌等高线数据建立了井喷H_2S扩散的CFD流场计算的有限元模型,结合当时气象条件,用Fluent软件的UDF功能编写了边界问歇风速的函数,数学模型中采用了适合于预测大气流动的大涡模拟运动方程,将CFD有限元模型和建立的数学模型用Fluent软件的解算器,对H_2S气体的扩散和运移规律进行了详细的数值模拟研究,获得了H_2S气体在该井场周围山谷地形的积聚、运移规律以及风向对气云扩散的影响,获得了H_2S和CH_4两种气体扩散的时空分布云图.模拟结果和事故现场调查结果一致.%The high-pressure blowout with H_2S is a complex problem of diffusion, involving gas mixture, gas movement, dispersion, and the influences by the meterological condition and complex topography. Therefore, a numerical simulation was carried out on the study of large-space flow field by the viable computational fluids dynamics (CFD). A finite element method was built up on the CFD flow field by the H_2S diffusion of a gas blowout according to the 3D topographic.contour data of this serious gas blowout occurred in Kai County of Chongqing. Then based on the meterological condition when this accident hap-pened, a function of boundary intermittent wind speed was written with the function of UDF in the ANSYS-Fluent software, a motion equation of Large Eddy Simulation adaptable to air flow forecast was used in the mathematical model, and the CFD finite element method and the mathematical model were input to the Fluent-CFD software calculator to simulate the laws of H_2S dif-fusion and movement. The results from simulation were shown as follows:(1) How

  15. 眼眶爆裂性骨折年龄因素与临床及影像学特点分析%The correlation analysis among age and clinical and imageological characteristics for orbital blow-out fractures

    Institute of Scientific and Technical Information of China (English)

    赵亮; 孙丰源; 唐东润; 潘叶

    2010-01-01

    Objective To analyze and compare the clinical and imageological characteristics of or- bital blow-out fractures between juvenile and adult,and analyze the correlation between clinical manifestations and imageological characteristics.Help the clinicians to analyze patients,conditions roundly and carefully and make reasonable treatment proposals.Methods Collected 75 patients with isolated orbital blow-out fracture whom clinical and imageological materials were completed from October 2006 to December 2008.All patients were divided into two groups:juvenile (≤18 years old,20 Cases) and adult (19-56 years old,55 cases).The ill history,clinical and imageological characteristics and the operative findings of all the cases were summarized. Meanwhile.statistical analysis was made.Results The main:reasons of orbital fractures were fall and violence in juvenile group and that in adult group were vehicle accident and violence.The difference of constituent ratio about gender and involved eyes between two groups had no statistical significance(P>0.05).The severity of enophthalmos in juvenile group was lower than in adult group (P0.05);青少年组术前双眼眼球突出度差值小于成年组(P<0.05);青少年组伤后出现恶心、呕吐症状的构成比高于成年组(P<0.05);两组受累眶壁之间的构成比差别有统计学意义(P<0.05);青少年组骨折区呈裂缝状或阀门样表现的构成比高于成年组(P<0.05);青少年组发生肌肉嵌夹的构成比高于成年组(P<0.05);青少年组手术见肌肉呈深紫色改变的构成比高于成年组(P<0.05).结论 青少年及成年人BOF的临床及影像学特点存在明显差异,结合临床及影像学特点综合分析对于评估患者病情及预后,及时准确地制定治疗方案有较大意义.

  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. Bunch modulation in LWFA blowout regime

    Czech Academy of Sciences Publication Activity Database

    Vyskočil, Jiří; Klimo, Ondřej; Vieira, J.; Korn, Georg

    Bellingham : SPIE, 2015 - (Ledingham, K.; Esarey, E.; Spohr, K.; Schroeder, C.; McKenna, P.; Gruner, F.; Bolton, P.), "95141E-1"-"95141E-7" ISBN 978-1-62841-635-0. ISSN 0277-786X. [Laser Acceleration of Electrons, Protons, and Ions III and Medical Applications of Laser-Generated Beams of Particles III. Praha (CZ), 13.04.2015-15.04.2015] R&D Projects: GA MŠk ED1.1.00/02.0061; GA MŠk EE2.3.20.0279; GA MŠk EE.2.3.20.0087 Grant ostatní: ELI Beamlines(XE) CZ.1.05/1.1.00/02.0061; LaserZdroj (OP VK 3)(XE) CZ.1.07/2.3.00/20.0279; OP VK 2 LaserGen(XE) CZ.1.07/2.3.00/20.0087 Institutional support: RVO:68378271 Keywords : electron injection * bunch modulation * LWFA Subject RIV: BC - Control Systems Theory

  18. 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。

  19. 针刺对爆裂性眶壁骨折致眼球运动障碍的疗效分析%Curative effect analysis of acupuncture on eye movement disorders caused by orbital blowout fracture

    Institute of Scientific and Technical Information of China (English)

    周凌云; 刘青松; 刘巧英

    2015-01-01

    OBJECTIVE To observe the acupuncture effect on extra ocular muscle points for eye movement disorders of burst orbital wall fracture. METHODS Sixty eye movement disorder patients with blowout orbital wall fracture were randomly divided into two groups:treatment group (30 cases) selected points on extra ocular muscle, depending on the type of orbital wall fracture, 1 time a day, retaining needle for 30 minutes, 15 days as a course, 2 courses each patient, and conventional drug treatment were given at the same time;Control group (30 cases) was only given routine drug treatment. Before and after treatment, eye movement disorder rating and the corresponding scope of corneal limbus mobile were observed. RESULTS 1.Treatment group: the scope of corneal limbus mobile before treatment, inward moving(4.80±3.01) mm, rebound(3.40±2.50) mm, depression(4.40±1.54) mm;the scope of corneal limbus mobile after treatment , inward moving (7.47±2.26) mm, rebound (4.70±1.74) mm, depression (5.47±0.78) mm. Control group:the scope of corneal limbus mobile before treatment, inward moving (5.17±2.78) mm, rebound (3.17±2.49) mm, depression (4.53±1.41) mm;the scope of corneal limbus mobile after treatment , inward moving (6.17 ±2.56) mm, rebound (3.57 ±2.27) mm, depression (4.70 ±1.26) mm. We compared them within groups, both groups had statistically significance (P<0.001); Comparing between the two groups after treatment, the difference was statistically significant (P<0.001). 2.The eye movement disorder rating of treatment group:before treatment, level 0, 1, 2, 3, 4 eyes number respectively 0, 5, 17, 8 eyes;after treatment , level 0, 1, 2, 3, 4 eyes number respectively 11, 13, 1, 5 eyes; Control group before treatment, level 0, 1, 2, 3, 4 eyes number respectively 0, 6, 17, 7 eyes, after treatment , level 0, Ⅰ,Ⅱ,ⅢandⅣeyes number respectively 4, 13, 6, 7 eyes. Two groups after treatment eye movement disorder improved. Comparison between the two groups after treatment, the

  20. 基于CFD的高含硫天然气井井喷失控射流数值模拟研究%A Study Based on the CFD for Jet Simulation about High-sour Gas Well Blowout Out of Control

    Institute of Scientific and Technical Information of China (English)

    胡坤

    2013-01-01

    利用计算流体动力学方法研究高含硫天然气井井喷失控喷射流场,建立井喷射流场数值计算模型,研究单一组分气体射流与多种不同气体组分情况下流场特征.结果表明:多组分气体射流扩散性要比单一组分更强,且各组分气体在空气中扩散很快,在距离井口垂直高度10 m的范围内,硫化氢质量百分比从20%衰减到5%以下,甲烷质量百分比从80%衰减到20%以下,甲烷在射流方向上的衰减速率要高于硫化氢.%Calculated the jet flow field about high - sour gas well by using the computational fluid dynamics approach , established numerical calculation model about blowout jet flow field, the single component gas jet and a variety of different gas composition conditions mean field characteristics are studed, and the results show that; the multicomponent gas jet diffusibility than a single component, stronger, and various components of the gas in the air diffusion soon, in the distance wellhead vertical height 10 m, within the scope of the hydrogen sulfide mass percent from 20% attenuation to less than 5% , the mass fraction of methane from 80% attenuation to less than 20% , methane in jet direction of attenuation rate than hydrogen sulfide.

  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 250.515 - Blowout prevention equipment.

    Science.gov (United States)

    2010-07-01

    ... power source, independent from the primary power source, with sufficient capacity to close all BOP... remote BOP-control station and one BOP-control station on the rig floor. (5) A choke line and a kill line... 250.515 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND...

  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. 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...

  5. 3C190: Probing the extreme AGN blowout phase of galaxy evolution

    Science.gov (United States)

    Goulding, Andy

    2014-09-01

    We propose joint 42ks Chandra ACIS-S & 4hrs(2+2) JVLA radio observations of 3C190, a z~1.2 merger-remnant harboring an extremely luminous compact steep spectrum radio QSO. A previous 3ks ACIS-S snapshot showed a powerful unobscured X-ray nucleus and possible extended hot gas. However, the multi-wavelength properties show 3C190 uniquely presents strong Si-absorption, and hence, a heavily obscured QSO. Our proposed observations will accurately constrain the intrinsic X-ray properties of the central QSO, including the obscuring column density and accretion rate, as well as discover the extent and properties of the extended hot gas. In turn, we will directly test if 3C190 is undergoing a short-lived, but pivotal, transition from an obscured to unobscured QSO.

  6. 30 CFR 250.1610 - Blowout preventer systems and system components.

    Science.gov (United States)

    2010-07-01

    ... design that it can be run through the BOP stack installed at the bottom of the kelly. A wrench to fit... fit the drill pipe in use. (c) Working pressure. The working-pressure rating of any BOP shall exceed... floor to fit all connections that are in the drill string. A wrench to fit the drill-string safety...

  7. 30 CFR 250.616 - Blowout preventer system testing, records, and drills.

    Science.gov (United States)

    2010-07-01

    .... Variable bore pipe rams must be pressure tested against the largest and smallest sizes of tubulars in use (jointed pipe, seamless pipe) in the well. (b) The BOP systems shall be tested at the following times: (1... stuck pipe or pressure-control operation and remedial efforts are being performed. The tests shall...

  8. 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.

  9. The car industry and the blow-out of the hydrogen hype

    Energy Technology Data Exchange (ETDEWEB)

    Bakker, Sjoerd [Utrecht University, Department of Innovation and Environmental Sciences, PO Box 80115, 3508 TC, Utrecht (Netherlands)

    2010-11-15

    The hydrogen hype of the last decade has passed and it is now seemingly substituted by the electric vehicle hype. A technological hype can have both positive as well as negative consequences. On the one hand it attracts sponsors for technology development but on the other hand the high expectations might result in disappointment and subsequent withdrawal of the sponsors. In this paper I ask the question to what extent the car industry has created the hype and how it has done so. The industry's role is studied through their prototyping activities and accompanying statements on market entry. I conclude that the car industry has indeed inflated the hype, especially through its public statements on market release after the turn of the millennium. Furthermore, it can be concluded that the industry has shown a double repertoire of both highly optimistic and more modest statements. It is possible that statements are used deliberately to serve the industry's interests whenever needed. Without neglecting the positive influence of technological hype on public policy and private funding for R and D efforts, more modest promises could serve the development of sustainable mobility better. For policy makers the challenge is to remain open to different options instead of following hypes and disappointments as they come and go. (author)

  10. The car industry and the blow-out of the hydrogen hype

    International Nuclear Information System (INIS)

    The hydrogen hype of the last decade has passed and it is now seemingly substituted by the electric vehicle hype. A technological hype can have both positive as well as negative consequences. On the one hand it attracts sponsors for technology development but on the other hand the high expectations might result in disappointment and subsequent withdrawal of the sponsors. In this paper I ask the question to what extent the car industry has created the hype and how it has done so. The industry's role is studied through their prototyping activities and accompanying statements on market entry. I conclude that the car industry has indeed inflated the hype, especially through its public statements on market release after the turn of the millennium. Furthermore, it can be concluded that the industry has shown a double repertoire of both highly optimistic and more modest statements. It is possible that statements are used deliberately to serve the industry's interests whenever needed. Without neglecting the positive influence of technological hype on public policy and private funding for R and D efforts, more modest promises could serve the development of sustainable mobility better. For policy makers the challenge is to remain open to different options instead of following hypes and disappointments as they come and go. (author)

  11. 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.

  12. 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

  13. 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)

  14. 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.

  15. 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

  16. 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. PMID:27117673

  17. Experimental data regarding the characterization of the flame behavior near lean blowout in a non-premixed liquid fuel burner

    Directory of Open Access Journals (Sweden)

    Maria Grazia De Giorgi

    2016-03-01

    The data are related to the research article “Image processing for the characterization of flame stability in a non-premixed liquid fuel burner near lean blowout” in Aerospace Science and Technology [1].

  18. The restraint of accidental blowout following the core meltdown of a bwr by release of pressure and filtering

    International Nuclear Information System (INIS)

    The report discusses core meltdown which may cause high pressure and blow the reactor containment. This might involve fission product release. A way to limit the release is to permit a controlled blowing of gases and vapour through a filter. The filter could be composed of a stonebed, a sandbed or a water basin. The specifications of a design applicable to a filtered release are discussed. (G.B.)

  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. Research on Pressure Retaining Technology of Hydraulic Blowout Preventer System%液压防喷系统的保压技术研究

    Institute of Scientific and Technical Information of China (English)

    张野

    2012-01-01

    三级保压技术实现了世界首创,目前国内国外还没有对需要保压的系统使用三级保压技术,属于创造发明技术.三级保压技术解决了带压作业中的核心关键技术问题,提高了整个系统的可靠性,推进了带压作业技术的发展,降低了成本、延长了设备的使用寿命.它的社会效益远大于经济效益.%The three stage pressure retaining technology achieved world's first, and currently, three stage pressure retaining technology is still not be used in system which needs pressure retaining at home and abroad, which belongs to invention technology. The technology solves key technical issues in operation under pressure, improves overall system reliability, promotes technical development of operation under pressure, and reduces costs, extends working life of equipments. Its social benefits are much larger than its economic benefits.

  1. 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.

  2. 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.

  3. 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.

  4. Detection of a Large Arc of Ionized Hydrogen Far Above the Cas OB6 Association A Superbubble Blowout into the Galactic Halo?

    CERN Document Server

    Reynolds, R J; Haffner, L M

    2001-01-01

    The Wisconsin H-Alpha Mapper (WHAM) Northern Sky Survey has revealed a loop of H II reaching 1300 pc from the Galactic midplane above the Cas OB6 association in the Perseus sprial arm. This enormous feature surrounds and extends far above the "W4 Chimney" identified by Normandeau et al. and appears to be associated with the star formation activity near the W3/W4/W5 H II region complex. The existence of this ionized structure suggests that past episodes of massive star formation have cleared the H I from an enormous volume above the Perseus arm, allowing Lyman continuum photons from O stars near the Galactic midplane to reach into the halo.

  5. Evolution of Hydrocarbon-Degrading Microbial Communities in the Aftermath of the Deepwater Horizon Oil Well Blowout in the Gulf of Mexico

    Science.gov (United States)

    Andersen, G.; Dubinsky, E. A.; Chakraborty, R.; Hollibaugh, J. T.; Hazen, T. C.

    2012-12-01

    The Deepwater Horizon oil spill created large plumes of dispersed oil and gas that remained deep in the water column and stimulated growth of several deep-sea bacteria that can degrade hydrocarbons at cold temperatures. We tracked microbial community composition before, during and after the 83-day spill to determine relationships between microbial dynamics, and hydrocarbon and dissolved-oxygen concentrations. Dominant bacteria in plumes shifted drastically over time and were dependent on the concentration of hydrocarbons, and the relative quantities of insoluble and soluble oil fractions. Unmitigated flow from the wellhead early in the spill resulted in the highest concentrations of oil and relatively more n-alkanes suspended in the plume as small oil droplets. These conditions resulted in near complete dominance by alkane-degrading Oceanospirillales, Pseudomonas and Shewanella. Six-weeks into the spill overall hydrocarbon concentrations in the plume decreased and were almost entirely composed of BTEX after management actions reduced emissions into the water column. These conditions corresponded with the emergence of Colwellia, Pseudoalteromonas, Cycloclasticus and Halomonas that are capable of degrading aromatic compounds. After the well was contained dominant plume bacteria disappeared within two weeks after the spill and transitioned to an entirely different set of bacteria dominated by Flavobacteria, Methylophaga, Alteromonas and Rhodobacteraceae that were found in anomalous oxygen depressions throughout August and are prominent degraders of both high molecular weight organic matter as well as hydrocarbons. Bio-Sep beads amended with volatile hydrocarbons from MC-252 oil were used from August through September to create hydrocarbon-amended traps for attracting oil-degrading microbes in situ. Traps were placed at multiple depths on a drilling rig about 600-m from the original MC-252 oil spill site. Microbes were isolated on media using MC-252 oil as the sole carbon source and characterized. Pure cultures were obtained from bacteria similar to those found to dominate hydrocarbon plumes and anomalous oxygen depressions by molecular community analysis. Respirometry studies confirmed that the isolates were able to metabolize the MC-252 oil. Our results from both molecular and culture analysis indicate that indigenous psychrophilic consortia of microorganisms thriving at 5°C from the oil-plume depth water were able to rapidly respond to dispersed oil at depth. The microbial community was highly dynamic and structured by changes in hydrocarbon composition over time. The spill caused sustained alterations in subsurface microbial communities and impacted the deep ocean for at least months after well containment.

  6. Polycyclic hydrocarbon biomarkers confirm selective incorporation of petroleum in soil and kangaroo rat liver samples near an oil well blowout site in the western San Joaquin Valley, California

    International Nuclear Information System (INIS)

    Following an accidental oil well blow out at an oil field in the western part of the San Joaquin Valley, soil samples and specimens of Heermann's kangaroo rats (Dipodomys heermanni) were collected from two oil-impacted areas and one control area. Fingerprinting by GC-MS and quantitative evaluation of metabolized petroleum hydrocarbons was performed on oil, soil extracts, and rat livers. A liver from a domestically raised rabbit was used as an experimental control. The results show that there is no significant incorporation of PAHs or low molecular weight n-alkanes (C13--C25) into the liver tissues. The C25--C35 n-alkane range for all soil samples, kangaroo rat livers, and rabbit liver, is dominated by a high abundance of C27, C29, C31, and C33 hydrocarbons typical of epicuticular plant waxes. In all liver tissue samples, squalene, the cholesterol precursor, is the dominant hydrocarbon. Although evidence is lacking for metabolism of PAHs and paraffinic petroleum hydrocarbons, very strong evidence is available for incorporation of a set of polycyclic hydrocarbons (biomarkers) belonging to the terpane, sterane, and monoaromatic and triaromatic sterane families, identified by ion monitoring at 191, 217, 253, and 231 m/z, respectively. Because these hydrocarbons are not known to exist in the biosphere, but are only synthesized during oil- and coal-forming processes, their presence in the liver samples constitutes proof for crude oil incorporation into tissues. This conclusion is further substantiated by the selective incorporation of only the 20S enantiomer of C28 and C29 steranes and aromatic steranes into the livers, with the exclusion of the 20R enantiomer. The results from the study conclusively demonstrate that polycyclic hydrocarbon biomarkers provide excellent indices for proof of petroleum exposure and metabolism in some terrestrial herbivores

  7. 经伤椎椎弓根椎体内植骨治疗胸腰椎爆裂性骨折临床观察%Clinical Observation of Blowout Fracture Within the Vertebral Pedicle Bone Graft for Thoracolumbar

    Institute of Scientific and Technical Information of China (English)

    陈煜东

    2015-01-01

    Objective To observe the pedicle bone graft for thoracolumbar burst fracture treatment. Methods 65 cases of thoracolumbar fracture patients were chosen from May 2011 to October 2012 in our hospital, they were given by pedicle bone graft treatment, surgery to vertebral CT taken as the center piece and X ray, fracture healing state, vertebral height and Cobb angle changes to improve the situation. Results The patients were followed up 0.5~3 years, the excellent was 87.69%in this group, all patients were low back pain, no fracture fixation, failure, loosening and other complications. Conclusion The administration of thoracolumbar burst fracture patients by internal pedicle bone graft treatment, helps promote healing, strengthen before vertebral column stability, reduce long-term complications.%目的:观察经伤椎椎弓根椎体内植骨对胸腰椎爆裂性骨折的治疗效果。方法选择2011年5月~2012年10月我院收治的65例胸腰椎爆裂性骨折患者,均给予经伤椎椎弓根椎体内植骨治疗,术后以伤椎为中心拍摄CT片及X线片,观察骨折愈合状态、伤椎高度变化及Cobb角改善情况。结果术后随访0.5~3年,本组优良率为87.69%,所有患者均未出现腰背疼痛,无内固定断裂、失效、松动等并发症。结论给予胸腰椎爆裂性骨折患者经伤椎椎弓根椎体内植骨治疗,有助于促进骨折愈合,加强伤椎前中柱稳定性,减少远期并发症发生。

  8. Clinical characteristics and management of juvenile orbital blow-out fracture%未成年人眶壁爆裂性骨折的临床特点及治疗分析

    Institute of Scientific and Technical Information of China (English)

    杨丽红; 唐东润; 孙丰源

    2009-01-01

    目的 分析未成年人不同年龄眶壁爆裂性骨折的临床特点与骨折类型的相关性.探讨少年儿童眶壁骨折的治疗方案.方法 选取18岁以下眶壁爆裂性骨折患者69例,5~14岁组23例和15~18岁组46例.观察术前眼位和复视情况.眼球内陷程度和眼球运动,CT影像特点表现和术中所见,术后眼位、眼球内陷和眼球运动恢复情况.结果 5~14岁组伤后出现恶心、呕吐,眼球垂直运动受限的构成比高于15~18岁组(P均0.05).There show larger constituent ratios of Nausea/vomiting and vertical duction limitation in 5 to 14 years of age group than that in 15 to 18 years of age group (P <0.05).Children between 5 to 14 years of age had less chance of enophthalmos than children between 15 to 18 years of age (P< 0.05).But they were more likely to have an orbital floor trapdoor type fracture (P<0.05).Operative findings showed 16 of 20 fracture defects were trapdoor type which were all detected as linear type fracture by computer tomography images.The inferior rectus muscle entrapped in orbital fracture site was amaranth and swelling. Children between 5 to 14 years of age seemed to have a higher probability and a more severer degree of infraduction defect than children 15 to 18 years of age postoperatively.Two patients between 5 to 14 years of age got an aggravating extraocular ductions limitation and diplopia once again in I week postoperatively.Conclusion There shows an increasing risk of sustaining an orbital floor trapdoor type fracture in children between 5 to 14 years of age.Prompt surgical intervention could improve extraocular ductions and reduce residue diplopia.

  9. Improved methods for reliability assessments of safety-critical systems: An application example for BOP systems

    OpenAIRE

    Pinker, Remi

    2012-01-01

    The failure of the Deepwater Horizon drilling rig's blowout preventer has been pointed to as one of the main causes of the Macondo accident on April 10th 2010. The blowout preventer system is one the most important safety barriers in a hydrocarbon well. The accident has created a demand for improved methods of assessing the reliability of blowout preventer systems. The objective of this master thesis is to propose improvements to current reliability assessment methods for complex safety criti...

  10. 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.

  11. Producer observations on the effects of sour gas in cattle

    International Nuclear Information System (INIS)

    The effects of poisonous substances emitted from uncontrolled sour gas wells on cattle are described, from the perspective of a farmer whose cattle were exposed to such emissions. Two events in the Drayton Valley area led to exposure of cattle to toxins: a sour gas well blowout in 1977 (Amoco 7-10 well) occurring 40 km from the farm, and the Lodgepole blowout (Amoco Dome Brazeau River) in 1982 that occurred 38 km from the farm. Cattle were exposed to raw sour gas and sour gas well exhaust for 67 days during the Lodgepole blowout. A marked effect on the weaning weight and feeding performance of calves in years after the blowout was observed. Exposure of replacement heifers to sour gas well blowout emissions greatly increased the cull rate of the animals. 5 figs., 3 tabs

  12. 交通事故中车辆轮胎爆胎分析

    Institute of Scientific and Technical Information of China (English)

    贾志鹏

    2014-01-01

    对汽车轮胎爆胎原因及其分析方法进行了分析。对准确区分主动性爆胎和被动性爆胎,正确分析和处理涉及爆胎交通事故提供相关方法。%The analysis of the cause of automobile tyre's bursting and the ways to analyze it.How to correctly distinguish active tyre blowout and passive tyre blowout.providing methods about correctly analysing and dealing with traffic accidents about tyre-blowout.

  13. Stellar feedback and redistribution of gas in the Magellanic Clouds

    International Nuclear Information System (INIS)

    Full text: We studied star formation and associated supernova induced gas blowout in the Magellanic Clouds. Their role in feeding the extended gaseous tails associated with the Clouds (the Magellanic Stream and the Leading Arm) with matter was investigated. (author)

  14. TECHNICAL BASIS DOCUMENT FOR VENTILATION SYSTEM FILTRATION FAILURE LEADING TO AN UNFILTERED RELEASE

    International Nuclear Information System (INIS)

    This document analyzed three scenarios involving failures of HEPA filtration systems leading to releases from liquid waste tanks. The scenarios are failure due to high temperature (fire), overpressure (filter blowout), and unfiltered release due to filter failure, improper installation. etc

  15. METHODOLOGY TO EVALUATE THE POTENTIAL FOR GROUND WATER CONTAMINATION FROM GEOTHERMAL FLUID RELEASES

    Science.gov (United States)

    This report provides analytical methods and graphical techniques to predict potential ground water contamination from geothermal energy development. Overflows and leaks from ponds, pipe leaks, well blowouts, leaks from well casing, and migration from injection zones can be handle...

  16. 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.

  17. Direct Laser Acceleration in Laser Wakefield Accelerators

    OpenAIRE

    Shaw, Jessica

    2016-01-01

    In this dissertation, the direct laser acceleration (DLA) of ionization-injected electrons in a laser wakefield accelerator (LWFA) operating in the quasi-blowout regime has been investigated through experiment and simulation. In the blowout regime of LWFA, the radiation pressure of an intense laser pulse can push a majority of the plasma electrons out and around the main body of the pulse. The expelled plasma electrons feel the electrostatic field of the relatively-stationary ions and are t...

  18. Numerical and Experimental Investigations of the Flow Field of Ionised Gases with Applications to High-Performance Electronics and Oil Shale Gasification

    OpenAIRE

    Al-Amayreh, Malik

    2013-01-01

    This thesis investigates two new applications of flow field ionised gases. The first application involves coupled electromagnetic and aerothermodynamic phenomena in an electrical contactor chamber. I studied a new blowout technique to control the speed of the flow. With this new blowout technique, the ionised gases can be generated between the electrodes to feed the coils with current. I observed that the recovery time for the case of higher current is less than that of the following low curr...

  19. The cool component and the dichotomy, lateral expansion, and axial rotation of solar X-ray jets

    International Nuclear Information System (INIS)

    We present results from a study of 54 polar X-ray jets that were observed in coronal X-ray movies from the X-ray Telescope on Hinode and had simultaneous coverage in movies of the cooler transition region (T ∼ 105 K) taken in the He II 304 Å band of the Atmospheric Imaging Assembly (AIA) on Solar Dynamics Observatory. These dual observations verify the standard-jet/blowout-jet dichotomy of polar X-ray jets previously found primarily from XRT movies alone. In accord with models of blowout jets and standard jets, the AIA 304 Å movies show a cool (T ∼ 105 K) component in nearly all blowout X-ray jets and in a small minority of standard X-ray jets, obvious lateral expansion in blowout X-ray jets but none in standard X-ray jets, and obvious axial rotation in both blowout X-ray jets and standard X-ray jets. In our sample, the number of turns of axial rotation in the cool-component standard X-ray jets is typical of that in the blowout X-ray jets, suggesting that the closed bipolar magnetic field in the jet base has substantial twist not only in all blowout X-ray jets but also in many standard X-ray jets. We point out that our results for the dichotomy, lateral expansion, and axial rotation of X-ray jets add credence to published speculation that type-II spicules are miniature analogs of X-ray jets, are generated by granule-size emerging bipoles, and thereby carry enough energy to power the corona and solar wind.

  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. Modeling in support of Corridor Resources Old Harry exploratory drilling environmental assessment

    International Nuclear Information System (INIS)

    During offshore petroleum activities, oil spills can occur and lead to significant environmental impacts. Corridor Resources Inc. is in the process of obtaining a license for exploratory drilling activities in the Old Harry and the aim of this study is to determine what would be the behavior and trajectory of any oil spill from these activities. Two types of spill were studied, sub-sea and surface spills. Modeling was carried out using Cohasset oil from the Scotian Basin, the properties of which are thought to be close to those of Old Harry oil, and the blowout rates were determined using reservoir information. Results showed that subsea blowouts would result in wide and thin surface slicks near the source while surface blowouts would be narrow and thick; surface slicks would persist over a 5km range from the source before dispersion.

  2. Nonlinear Laser Driven Donut Wakefields for Positron and Electron Acceleration

    Science.gov (United States)

    Vieira, J.; Mendonça, J. T.

    2014-05-01

    We show analytically and through three-dimensional particle-in-cell simulations that nonlinear wakefields driven by Laguerre-Gaussian laser pulses can lead to hollow electron self-injection and positron acceleration. We find that higher order lasers can drive donut shaped blowout wakefields with strong positron accelerating gradients comparable to those of a spherical bubble. Corresponding positron focusing forces can be more than an order of magnitude stronger than electron focusing forces in a spherical bubble. Required laser intensities and energies to reach the nonlinear donut shaped blowout are within state-of-the-art experimental conditions.

  3. 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.

  4. 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.

  5. Investigating animal health effects of sour gas acid forming emissions

    International Nuclear Information System (INIS)

    The effects of sour gas well blowout emissions on livestock are reviewed. Guidelines for safe drilling operations in hydrogen sulfide environments, general hazards and characteristics of hydrogen sulfide, and guidelines for field investigation into the effects of sour gas and acid emissions on livestock are discussed. A case history involving the Ross No. 2 gas well blowout of July 1985 in Rankin County, Mississippi is presented. The blowout lasted for 72 days, and at peak discharge the 500 ppM radius was ca 3.5 miles. A cattle embryo transplant operation located one half mile from the well was affected by the blowout. Examination by a local veterinarian of the cattle demonstrated eye irritation, epiphora, nasal discharge and coughing. After one and a half months of exposure, most animals showed clinical signs of a severe dry hacking cough, epiphora, dry rales over the thoracic inlet, and a bronchial popping sound over the lateral thorax. All animals had eye irritation. Of 55 animals showing signs of respiratory distress and eye irritations, 15 were still clinically ill in May of 1986. 7 refs., 1 tab

  6. 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.

  7. 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

  8. 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.

  9. 30 CFR 250.448 - What are the BOP pressure tests requirements?

    Science.gov (United States)

    2010-07-01

    ... have approved those test pressures in your APD. (c) High pressure test for annular-type BOPs. The high... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What are the BOP pressure tests requirements... Blowout Preventer (bop) System Requirements § 250.448 What are the BOP pressure tests requirements?...

  10. 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.

  11. THE RISK ASSESSMENT OF TOXIC DEFEAT OF THE PEOPLE IN THE ACCIDENTAL EMISSION OF HAZARDOUS CHEMICAL SUBSTANCES

    Directory of Open Access Journals (Sweden)

    O. Yu. Gunko

    2008-01-01

    Full Text Available The 3D numerical model to simulate the toxicant propagation at an industrial site after the emergency blow-out was developed. The model is based on the transport gradient model and the model of inviscous incompressible fluid. The results of numerical experiments are presented.

  12. Numerical investigation of beam-driven PWFA in quasi-nonlinear regime

    CERN Document Server

    Londrillo, P; Ferrario, M

    2014-01-01

    In beam-driven Plasma Based Wakefield Acceleration (PWFA), the quasi-nonlinear model has been designed to combine high efficient 'blowout' regimes, where cold and overdense driving electron beams form a totally rarefied plasma channel, with low charge beam distribution assuring the excited wakefield preserves relevant linear properties.

  13. Instability of a witness bunch in a plasma bubble

    CERN Document Server

    Burov, A; Nagaitsev, S

    2016-01-01

    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.

  14. 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

  15. 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.

  16. 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

  17. 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

    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....

  18. Flow-Induced Vibrations in a Steam Blow-0ut Line of a Power Plant

    International Nuclear Information System (INIS)

    We consider in this work the large amplitude flow-induced vibrations in a steam blow-out line of a power plant. A low-order, parametrically excited, coupled nonlinear dynamical system is formulated 1iom the describing boundary value problem. Analysis of system response enables identification of governing mechanisms of: instability and complex aperiodic vibrations

  19. Technical basis document for ventilation system filtration failures leading to unfiltered release

    International Nuclear Information System (INIS)

    Three accident scenarios were analyzed involving failures of HEPA filtration systems leading to releases FR-om liquid waste tanks. The scenarios are failure due to high temperature (fire), overpressure (filter blowout), and unfiltered release due to filter failure, improper installation, etc

  20. Preventing accidents at intake towers

    Energy Technology Data Exchange (ETDEWEB)

    Villegas, F. (INTEGRAL S.A., Medellin, CO (United States))

    1994-03-01

    Strong air blow-outs occurring in the intake tower of Guatape Hydroelectric Power Plant in Colombia have caused two serious accidents recently. The causes of the accidents were investigated and recommendations are made here to prevent future repetitions of these dangerous events. (UK)

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

    International Nuclear Information System (INIS)

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

    International Nuclear Information System (INIS)

    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)

  3. 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.

  4. Supplementary information on Series II Test A-5 test conditions

    International Nuclear Information System (INIS)

    Test planning and test preparation for LLTR Series II Test A-5 are continuing at GE and ETEC. The main objective for this test is to obtain data on the type and magnitude of steam tube blowout failures resulting from worst case leak conditions under the superheater hot standby condition (i.e., the plant condition considered most susceptible to steam tube blowout failures from wastage/overheating). A corollary objective is to add large quantities of steam (i.e. approx. 330 lbs) to simulate the amount that could be added in a plant system (such as CRBRP) before pressure would build up in the intermediate Heat Transport System to blow the expansion tank rupture disc. This report recommends the preferred method for operating the LLTR primary/secondary steam systems for Test A-5. i.e., Option 5 - Common Supply Tanks for Primary and Secondary Systems

  5. Developments in new aircraft tire tread materials. [fatigue life of elastomeric materials

    Science.gov (United States)

    Yager, T. J.; Mccarty, J. L.; Riccitiello, S. R.; Golub, M. A.

    1976-01-01

    Comparative laboratory and field tests were conducted on experimental and state-of-the-art aircraft tire tread materials in a program aimed at seeking new elastomeric materials which would provide improved aircraft tire tread wear, traction, and blowout resistance in the interests of operational safety and economy. The experimental stock was formulated of natural rubber and amorphous vinyl polybutadiene to provide high thermal-oxidative resistance, a characteristic pursued on the premise that thermal oxidation is involved both in the normal abrasion or wear of tire treads and probably in the chain of events leading to blowout failures. Results from the tests demonstrate that the experimental stock provided better heat buildup (hysteresis) and fatigue properties, at least equal wet and dry traction, and greater wear resistance than the state-of-the-art stock.

  6. Aortic Stent-Graft Infection Following Septic Complications of a Kidney Stone

    International Nuclear Information System (INIS)

    A 73-year-old man was treated because of a renal pelvis blowout of the left kidney for which he received a nephrostomy catheter without antibiotic prophylaxis. Almost a year previously this patient had undergone endovascular repair of a symptomatic infrarenal abdominal aorta aneurysm. Four weeks after the diagnosis and treatment of the ruptured renal pelvis, a new computed tomography scan and ultrasound-guided fine needle aspiration confirmed the diagnosis of infected aortic stent-graft. An extra-anatomic axillo-uniiliac bypass and graft excision was performed. Two weeks after discharge the patient returned to the hospital with an occlusion of his left renal artery and died of renal failure. This is the first time an infected aortic stent-graft after a renal pelvis blowout has been reported. Although infections of aortic stent-grafts occur rarely, one should be aware of the possibility in aortic stent-graft patients undergoing abdominal procedures without antibiotic prophylaxis

  7. 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.

  8. 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.

  9. Disturbance in dry coastal dunes in Denmark promotes diversity of plants and arthropods

    DEFF Research Database (Denmark)

    Brunbjerg, Ane Kirstine; Jørgensen, Gorm Pilgaard; Nielsen, Kristian Mandsberg;

    2015-01-01

    of three disturbance types (burning, trampling and blowouts) on plant and arthropod species richness and composition in dry coastal dunes in Jutland, Denmark. Environmental variables, plant presence–absence and arthropod abundance were measured in 150 1 × 2 m plots along transects in blowouts, burned......Naturally disturbed coastal dunes have become strongly reduced during the last century due to the cessation of grazing by domestic herbivores, dune stabilization initiatives, and increasing nitrogen deposition, all promoting encroachment by grasses, shrubs and woody plants. We assessed the effects...... the difference in colonization potential. A combination of disturbances maximized diversity, suggesting that re-installment of a diverse disturbance regime should be considered in dune management....

  10. 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.

  11. Severe Pulmonary Valve Regurgitation 40 Years After Blunt Chest Trauma.

    Science.gov (United States)

    Fuglsang, Simon; Heiberg, Johan; Hjortdal, Vibeke Elisabeth

    2015-10-01

    Severe pulmonary valve regurgitation caused by a pulmonary valve tear is a rare complication to a blunt chest trauma. In this case report, we present a patient with pulmonary regurgitation originating from a chest trauma 40 years ago. Possible mechanisms are osseous pinch of the pulmonary valve between the anterior chest wall and the vertebral column, and retrograde blowout from severe compression of the lungs. PMID:26434447

  12. The tidelands oil controversy: The prize and the responsibility

    Energy Technology Data Exchange (ETDEWEB)

    Hagar, A.V.

    1995-12-31

    This article reviews the legal history of the Tidelands oil controversy in the Santa Barbara Channel of Southern California. A blowout of a well in an offshore platform in 1969 marked the beginning of California`s anti-oil movement. Santa Barbara today is a combination of industrialization and recreation, and like the oil and water that are the lifeblood of these two pursuits, they do not mix.

  13. Structural analysis to determine the stress induced loading on Wellhead Housing system supported by CAN and sea bed BOP supporter

    OpenAIRE

    Illendala, Pavan Kumar

    2012-01-01

    The present work investigates the effect of the bending loads on the wellhead systems and predicts the response of the conductor with the introduction of CAN™ (Conductor Anchor Node) and Seabed BOP Supporter. Performance of the wellhead and conductor system is dependent on field design parameters. These parameters can include local environmental loading, drilling rig motions, marine riser stack-ups and BOP (Blow-out Preventer) configuration and soil conditions. These loads may ...

  14. Extraction and Characterization of Drilling Fluid from Castor Oil

    OpenAIRE

    Manase Auta

    2013-01-01

    Drilling fluid is an essential component in drilling operations. It is used to prevent blowouts by creating adequate hydrostatic pressure, lubricating the walls of a well and the drill string, flushing to the surface of cuttings, and keeping the drill bit clean and cool. Extraction, characterization and formation of drilling fluid from castor seed oil were investigated. The castor seeds used were obtained from a local market and the extraction of the oil was done mechanically. The extracted o...

  15. Experimentelle Untersuchungen an abgehobenen Flammen unter Druck

    OpenAIRE

    Kasabov, Plamen

    2014-01-01

    Lifted flames are characterized by a high degree of fuel-air mixture homogeneity, giving the opportunity to reduce temperature peaks within the flame and lower the NOx emissions. Compared to other low-NOx technologies, lifted flame combustion systems a valued for their excellent safety. Utilizing liquid kerosene as fuel, the impact of a variety of parameters on flow field, fuel evaporation, flame position, emissions and lean blow-out was investigated at elevated pressure conditions.

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

    OpenAIRE

    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 risk assessment of oils, narcosis (the disruption of an organism’s membrane structure) is the only mode of action assumed to determine the toxicity of petroleum hydrocarbons. However, several crude ...

  17. Transcriptional response of bathypelagic marine bacterioplankton to the Deepwater Horizon oil spill

    OpenAIRE

    Rivers, Adam R; Sharma, Shalabh; Tringe, Susannah G.; Martin, Jeffrey; Joye, Samantha B.; Moran, Mary Ann

    2013-01-01

    The Deepwater Horizon blowout released a massive amount of oil and gas into the deep ocean between April and July 2010, stimulating microbial blooms of petroleum-degrading bacteria. To understand the metabolic response of marine microorganisms, we sequenced ∼66 million community transcripts that revealed the identity of metabolically active microbes and their roles in petroleum consumption. Reads were assigned to reference genes from ∼2700 bacterial and archaeal taxa, but most assignments (39...

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

    OpenAIRE

    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. However, many primary cause of the disasters, such as BP’s Texas City and Deepwater Horizon, are rooted in management decisions and organizational. Therefore, there is a strong need to develop a risk m...

  19. Deadly Gas Accident Leads to CNPC's Management Reshuffling

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ Ma Fucai resigned from the position as president of China National Petroleum Corporation (CNPC),the nation's largest oil company, on April 14 taking responsibility for the gas well blowout in Southwest China's Chongqing that killed 234 people on December 23, 2003. Vice president of CNPC Chen Geng stepped in as head of the oil giant. Chen was also president of the overseas-listed PetroChina at that time, of which CNPC is the parent company.

  20. Coupled multiphysics modeling of gas hydrate bearing sediments

    OpenAIRE

    Sanchez, Marcelo; Gai, Xuerui; Santamarina, J. Carlos

    2014-01-01

    Gas hydrates are crystalline clathrate compounds made of water and a low molecular gas like methane (Sloan 1998). Gas hydrates are generally present in oil-producing areas and in permafrost regions. Methane hydrate deposits can lead to large-scale submarine slope failures, blowouts, platform foundation failures, and -borehole instability. Gas hydrates constitute also an attractive source of energy as they are estimated to contain very large reserves of methane. Hydrate formation, dissociation...

  1. Identifying and evaluating high risk areas and challenges on marine drilling riser system in relation to deepwater problems

    OpenAIRE

    Iversen, Alexander

    2012-01-01

    The main concerns during drilling operations are riser integrity and maintaining well control. This thesis has mainly been focusing on the problems and challenges faced with the marine riser system to illuminate high risk areas related to riser integrity. A marine riser system consists generally of four main elements; the upper marine riser package, riser joints, lower marine riser package, and the blowout preventer, each playing an important part in the marine riser system. The marine r...

  2. Nonlinear Model Predictive Pressure Control during Drilling Operations

    OpenAIRE

    Breyholtz, Øyvind

    2008-01-01

    Drilling into mature, depleted fields is often difficult because of tight pressure margins. Increasing the pressure control will enable wells that previously were considered undrillable, to be drilled. Enabling drilling and increased oil recovery from depleted fields would most likely lead to a substantial increase in profit margains. A better pressure control will also increase the safety of the drilling crew, because the risk of unwanted situations such as a kick or a blow-out is decreased,...

  3. Arctic innovation : Devon creates alternative to traditional relief well contingency

    International Nuclear Information System (INIS)

    An alternate well kill (AWK) system developed by Devon Canada and Cooper Cameron Corporation was reviewed. At a development cost of $2 million, it is hoped that the AWK system will offer an on-site, fail-safe means to kill a well, thereby negating the need for elaborate relief well drilling contingencies. An AWK unit has already been transported for testing at a well site in the Beaufort Sea. AWK systems are set for installation into blowout prevention stacks when drilling reaches the blowout risk threshold depth of 500 to 800 metres. The AWK system is ideal for use in the Arctic, where contingency planning for wells is vital due to the Arctic's slow regeneration rates, its short drilling season, and its remoteness. Consisting of a super shear and seal blowout prevention (BOP), the AWK provides the same capability of a BOP while also allowing any obstruction in the hole to be cut while simultaneously achieving a seal. Once activated, high density fluids are pumped down the hole to kill the well. The AWK is designed to be installed below the regular shear rams and BOP, and to operate entirely independently of all other systems in case of a severe power failure. Testing of the AWK is ongoing, even as final drilling preparations are underway. A worst-case scenario blowout and spill could ravage the environment and cost companies hundreds of millions of dollars in control and cleanup costs. Traditionally, relief wells can take up to 6 weeks to drill, during which time hydrocarbons are being released into the environment. The National Energy Board (NEB) has already gained a general acceptance of the AWK concept. 3 figs

  4. Renewable energy policy Comparison between EU and China - An empirical analysis with experience curve on EU and Chinese Solar industry

    OpenAIRE

    Gao, Jiabin

    2014-01-01

    The renewable energy sources (RES) has been largely adopted in the world, especially European Union and it has become the main market for wind energy and solar photovoltaic energy. With the stimulation impact from the Feed-in tariffs (FIT), the Solar PV market blowout since 2004. However, even tough with the stimulation of support schemes, the solar energy is still beyond publics bearing. The European Union and China have both massively utilized renewable energy in the recent years. There...

  5. Transverse instability and riddled basins in a system of two coupled logistic maps

    DEFF Research Database (Denmark)

    Maistrenko, Yu.L.; Maistrenko, V.L.; Popovich, A.;

    1998-01-01

    The paper examines the conditions for the appearance of riddled basins of attraction for a system of two symmetrically coupled logistic maps. We determine the regions in parameter space where the transverse Lyapunov exponent is negative and obtain the bifurcation curves for the transverse...... destabilization of low-periodic orbits embedded in the synchronized chaotic state. The changes in the attractor and its basin of attraction when scanning accross the riddling and blowout bifurcations are explained....

  6. The Strategic Transformation of Automobile Industry in China

    OpenAIRE

    Som Techakanjanakit; Meifang Huang

    2012-01-01

    In the past few years, the global automobile industry is developing difficultly because of the influence from the financial crisis. In contrast, China's automobile production and sales are still having a blowout type growth, and jumped into the world's largest automobile production and sales market. At the same time, Chinese automobile companies continue to deepen and join with international brand cooperation; independent research and development of the independent brand production, and their...

  7. Accidents associated with oil and gas operations: Outer continental shelf, 1956-1990. Final report

    International Nuclear Information System (INIS)

    The report is a compilation of descriptions of all blowouts, explosions and fires, pipeline breaks or leaks, significant pollution incidents, and major accidents that occurred on federally leased offshore lands from 1956 through 1990. The report identifies accidents by area, block number, lease number, platform number, well number, and operator. It describes the type of accident, corrective action taken, and the amount of pollution. It provides figures on fatalities, injuries, and property and environmental damage

  8. Acoustic detection of seabed gas leaks, with application to Carbon Capture and Storage (CCS), and leak prevention for the oil and gas industry

    OpenAIRE

    Berges, B.J.P.

    2015-01-01

    The acoustic remote sensing of subsea gas leakage, applied to the monitoring of underwater gas discharges from anthropogenic and natural sources, is becoming increasingly important. First, as the oil and gas industry is facing increasing regulation, there is a need to put more control in the industrial process and to assess the impact on the marine environment. The applications are diverse, including: early warnings of "blow-out" from offshore installations, detection of leaks from underwater...

  9. 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.

  10. 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.

  11. The Threats from Oil Spills: Now, Then, and in the Future

    Energy Technology Data Exchange (ETDEWEB)

    Jerneloev, Arne (Vienna (Austria)), e-mail: arne.jernelov@chello.at

    2010-07-15

    The recent oil spill from the blown-out well by the name of Macondo, drilled by the ill-fated rig Deepwater Horizon, has many features in common with another blowout in the Mexican Gulf that happened three decades ago. Then the oil gushed out from the Ixtoc I well drilled by the Sedco 135-F semi-submersible rig. In the years between these catastrophes, the source and nature of oil spills have undergone large changes. Huge spills from tankers that ran aground or collided used to be what caught the headlines and caused large ecological damage. The number and size of such accidental spills have decreased significantly. Instead, spills from ageing, ill-maintained or sabotaged pipelines have increased, and places like Arctic Russia, the Niger Delta, and the northwestern Amazon have become sites of reoccurring oil pollution. As for blowouts, there is no clear trend with regard to the number of incidences or amounts of spilled oil, but deepwater blowouts are much harder to cap and thus tend to go on longer and result in the release of larger quantities of oil. Also, oil exploration and extraction is moving into ever deeper water and into stormier and icier seas, increasing potential risks. The risk for reoccurring spills like the two huge Mexican Gulf ones is eminent and must be reduced

  12. The evolution of wellhead containment : to avoid leaks, it pays to be proactive

    International Nuclear Information System (INIS)

    This article described the advantages of the two wellhead spill containment systems. Wellhead seepage can quickly lead to environmental damage requiring expensive clean up. The Titan spill containment system is practical, durable, and compatible with all artificial lift systems, fits all types of wellhead stuffing boxes, protects ground and surface water beyond ERCB/EPA compliance, and withstands extreme temperature variations. The device offers protection from packing failure blowout and has high-level fluid shutdown capabilities for heavy leaks. The system also allows oil producers to monitor wells for carbon dioxide (CO2) seepage. The device captures oil and produced water that escapes the wellhead due to repetitive rod motion and common seal wear as well as all the fluids, emulsion, and torn seals during a seal replacement. The Heavy Oil Super Steam (SS) Unit, a safe, economical, and user-friendly wellhead containment unit and blowout suppression top cap, is designed for heavy oil producers and is particularly suitable for use in heavy oil wells using rod pumps, for cyclic steam stimulation (CSS), steam assisted gravity drainage (SAGD), and cold lift recovery. The fluid capture design of the SS eliminates corrosion to surface casing and cement seals on steamed heavy oil wells. The device reduces packing failure blow-outs and suppresses hot (wind-blown) oil contaminants at pad sites, improving safety while lessening environmental harm and lowering field operating costs. 4 figs.

  13. Experimental analysis of oxygen-methane combustion inside a gas turbine reactor under various operating conditions

    International Nuclear Information System (INIS)

    The oxygen-methane diffusion flame taking place in a gas turbine reactor was investigated experimentally with emphasis on flame stability. The oxidizer is a mixture of O2 and CO2 and the oxy-combustion process was studied at different equivalence ratios ranging from Φ = 0.5 to 1.0 and different O2/CO2 mixture composition (100/0, 80/20, 60/40, 50/50, 40/60, 30/70 and 25/75). The flame blowout condition was achieved through the reduction of oxygen percentage in the oxidizer mixture. Measurements were obtained for the flue gas temperature and concentration as well as flame visualization. It was found that the flame is very stable at the equivalence ratio of 0.65. At this ratio, the flame blows out at an O2/CO2 blending ratio of 22/78 for the case of fuel flow rate of 6 L/min and at a blending ratio of 21/79 for the case of fuel flow rate of 9 L/min. Attempts for operating the burner with less than 21% O2 were unsuccessful at all ranges of the operating parameters and resulted in unstable operation and blowout. Moreover, it was observed that the stabilization behavior did not change significantly with the variation of the fuel volume flow rate. It was also found that both flame and flue gas temperatures are reduced with the increase of the equivalence ratio. - Highlights: • Stability and characteristics of oxy-combustion diffusion flame were investigated. • The flame blowout conditions was determined. • Visualization of flame is carried out and the exhaust gas temperature is measured. • It was found that the most stable flame is at an equivalence ratio of 0.65. • Attempts for operating the burner with less than 21% O2 were unsuccessful

  14. Electrical sintering characteristics of inkjet-printed conductive Ag lines on a paper substrate

    International Nuclear Information System (INIS)

    The electrical sintering characteristics of inkjet-printed line patterns on a paper substrate were investigated by varying initial pattern resistance, input voltage, sintering time, and input voltage profile. The initial resistance was controlled by preheating the patterns, and its range was between 500 Ω and 5 MΩ. Depending on the input voltage and initial resistance, there exist three different regions: sintering, no change, and blowout. While no sintering is observed for too high initial resistance, blowout of printed lines occurs for a larger input voltage. For the initial resistance lower than ∼ 100 kΩ and the input voltage ranging from 20 V to 40 V, all the printed lines are electrically sintered within a short time without damaging the underlying paper substrates. When using the two-step voltage profile, the final resistance of lines becomes five times smaller than the resistance with the one-step voltage profile due to the increase in the grain size and the reduction in the void area, and no burning or blowout occurs in the lines. Due to its many advantages, the electrical sintering can provide a fast, reliable and effective way to fabricate high quality inkjet-printed conductive patterns for various printed electronics applications. - Highlights: • Electrical sintering characteristics of inkjet-printed Ag lines were investigated. • Initial resistance and input voltage greatly affect the sintering performance. • Sintering does not occur with high initial resistances or input voltages. • Under proper conditions, Ag lines are well-sintered within a very short time. • The sintering performance can be greatly improved by a two-step voltage profile

  15. Properties of large-scale methane/hydrogen jet fires

    International Nuclear Information System (INIS)

    A future economy based on reduction of carbon-based fuels for power generation and transportation may consider hydrogen as possible energy carrier Extensive and widespread use of hydrogen might require a pipeline network. The alternatives might be the use of the existing natural gas network or to design a dedicated network. Whatever the solution, mixing hydrogen with natural gas will modify the consequences of accidents, substantially The French National Research Agency (ANR) funded project called HYDROMEL focuses on these critical questions Within this project large-scale jet fires have been studied experimentally and numerically The main characteristics of these flames including visible length, radiation fluxes and blowout have been assessed. (authors)

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

    Science.gov (United States)

    Mehrling, T. J.; Robson, R. E.; Erbe, J.-H.; Osterhoff, J.

    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.

  17. Some Operating Experience and Problems Encountered During Operation of a Free-jet Facility

    Science.gov (United States)

    Mcaulay, John E; Prince, William R

    1957-01-01

    During a free-jet investigation of a 28-inch ram-jet engine at a Mach number of 2.35, flow pulsation at the engine inlet were discovered which proved to have an effect on the engine performance and operational characteristics, particularly the engine rich blowout limits. This report discusses the finding of the flow pulsations, their elimination, and effect. Other facility characteristics, such as the establishment of flow simulation and the degree of subcritical operation of the diffuser, are also explained.

  18. 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.

  19. 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

  20. 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.

  1. Dynamic analysis of the gantry crane used for transporting BOP

    Directory of Open Access Journals (Sweden)

    Stanisław WOJCIECH

    2008-01-01

    Full Text Available In the paper the dynamic analysis of a gantry crane used for transporting of BOP (BlowOut Preventer is presented. The crane is placed on a drilling platform. Sea waves cause motion of the platform and the load. Description of such systems can be used in the design process of control systems which allows us to compensate waving. Homogenous transformations and joint coordinates are used to describe behavior of the system. Equations of motion are derived using the Lagrange equations of the second order. In the paper the results of numerical calculations are presented as well.

  2. The natural gas market

    International Nuclear Information System (INIS)

    This chapter presents a brief history of the natural gas market highlighting the changes in the gas market and examining risk management in practice detailing the types of price risks, and the use of hedging using forwards and swaps. Options to manage risk are identified, and the role of risk management in financing, the role of the intermediary, and the market outlook are discussed. Panels describing the market structure, storage and natural gas risk management, the art of risk management, the winter 1995-96 basis blowout, spark spreads, the UK gas market and Europe, and weather derivatives are presented

  3. Well bore Flow Treatment Used to Predict Radioactive Brine Releases to the Surface from Future Drilling Penetrations into the Waste Isolation Pilot Plant (WIPP), New Mexico, USA

    International Nuclear Information System (INIS)

    The Waste Isolation Pilot Plant (WIPP) is the U.S. Department of Energy's (DOE) mined geologic repository in southeastern New Mexico, USA.This site is designed for the permanent burial of transuranic radioactive waste generated by defense related activities.The waste produces gases when exposed to brine. This gas generation may result in increased pressures over time. Therefore, a future driller that unknowingly penetrates through the site may experience a blowout. This paper describes the methodology used to predict the resultant volumes of contaminated brine released

  4. Communications systems and methods for subsea processors

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Optical plasma torch electron bunch generation in plasma wakefield accelerators

    Science.gov (United States)

    Wittig, G.; Karger, O.; Knetsch, A.; Xi, Y.; Deng, A.; Rosenzweig, J. B.; Bruhwiler, D. L.; Smith, J.; Manahan, G. G.; Sheng, Z.-M.; Jaroszynski, D. A.; Hidding, B.

    2015-08-01

    A novel, flexible method of witness electron bunch generation in plasma wakefield accelerators is described. A quasistationary plasma region is ignited by a focused laser pulse prior to the arrival of the plasma wave. This localized, shapeable optical plasma torch causes a strong distortion of the plasma blowout during passage of the electron driver bunch, leading to collective alteration of plasma electron trajectories and to controlled injection. This optically steered injection is more flexible and faster when compared to hydrodynamically controlled gas density transition injection methods.

  6. Dark matter halos and the M-\\sigma relation for supermassive black holes

    OpenAIRE

    Larkin, Adam C; McLaughlin, Dean E.

    2016-01-01

    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 $R_e$ and velocity dispersions within $R_e$) to the properties of their dark-matter halos 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 mass...

  7. The Threats from Oil Spills: Now, Then, and in the Future

    OpenAIRE

    Jernelöv, Arne

    2010-01-01

    The ongoing oil spill from the blown-out well by the name of Macondo, drilled by the ill-fated rig Deepwater Horizon, has many features in common with another blowout in the Mexican Gulf that happened three decades ago. Then the oil gushed out from the Ixtoc I well drilled by the Sedco 135-F semi-submersible rig. In the years between these catastrophes, the source and nature of oil spills have undergone large changes. Huge spills from tankers that ran aground or collided used to be what caugh...

  8. Initial experience of oculodynamic MRI using ultrafast T2-weighted imaging

    International Nuclear Information System (INIS)

    We designed cine MRI protocol using sequential static half-Fourier single-shot rapid acquisition with relaxation enhancement (RARE) images with the subjects staring at the series of targets in front of their eyes. This technique was applied to three healthy volunteers and four patients with ocular motility disorders, including blow-out fracture, globe restriction due to a large posterior staphyloma, neurogenic strabismus (convergence disorder), and intraocular adhesion. In the volunteers, smooth movements of their visual foci and extraocular muscles were observed. In the patients, the ocular movement disturbances were demonstrated. Oculodynamic MRI provides functional information in cases of diplopia. (author)

  9. 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.

  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. Real-time forecasting of ICME shock arrivals at L1 during the "April Fool's Day" epoch: 28 March ? 21 April 2001

    OpenAIRE

    Sun, W.; Dryer, M.; C. D. Fry; C. S. Deehr; Smith, Z.; Akasofu, S.-I.; M. D. Kartalev; Grigorov, K. G.

    2002-01-01

    International audience The Sun was extremely active during the "April Fool's Day" epoch of 2001. We chose this period between a solar flare on 28 March 2001 to a final shock arrival at Earth on 21 April 2001. The activity consisted of two presumed helmet-streamer blowouts, seven M-class flares, and nine X-class flares, the last of which was behind the west limb. We have been experimenting since February 1997 with real-time, end-to-end forecasting of interplanetary coronal mass ejection (IC...

  12. Real-time forecasting of ICME shock arrivals at L1 during the "April Fool’s Day" epoch: 28 March – 21 April 2001

    OpenAIRE

    Sun, W.; Dryer, M.; C. D. Fry; C. S. Deehr; Smith, Z.; Akasofu, S.-I.; M. D. Kartalev; Grigorov, K. G.

    2002-01-01

    The Sun was extremely active during the "April Fool’s Day" epoch of 2001. We chose this period between a solar flare on 28 March 2001 to a final shock arrival at Earth on 21 April 2001. The activity consisted of two presumed helmet-streamer blowouts, seven M-class flares, and nine X-class flares, the last of which was behind the west limb. We have been experimenting since February 1997 with real-time, end-to-end forecasting of interplanetary coronal mass ejec...

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

    International Nuclear Information System (INIS)

    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.)

  14. 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.

  15. An Option of Conservative Management of a Duodenal Injury Following Laparoscopic Cholecystectomy

    Directory of Open Access Journals (Sweden)

    MA Modi

    2014-01-01

    Full Text Available Duodenal injury following laparoscopic cholecystectomy is rare complications with catastrophic sequelae. Most injuries are attributed to thermal burns with electrocautery following adhesiolysis and have a delayed presentation requiring surgical intervention. We present a case of a 47-year-old gentleman operated on for laparoscopic cholecystectomy with a bilious drain postoperatively; for which an ERC was done showing choledocholithiasis with cystic duct stump blow-out and a drain in the duodenum suggestive of an iatrogenic duodenal injury. He was managed conservatively like a duodenal fistula and recovered without undergoing any intervention.

  16. Beyond injection: Trojan horse underdense photocathode plasma wakefield acceleration

    International Nuclear Information System (INIS)

    An overview on the underlying principles of the hybrid plasma wakefield acceleration scheme dubbed 'Trojan Horse' acceleration is given. The concept is based on laser-controlled release of electrons directly into a particle-beam-driven plasma blowout, paving the way for controlled, shapeable electron bunches with ultralow emittance and ultrahigh brightness. Combining the virtues of a low-ionization-threshold underdense photocathode with the GV/m-scale electric fields of a practically dephasing-free beam-driven plasma blowout, this constitutes a 4th generation electron acceleration scheme. It is applicable as a beam brightness transformer for electron bunches from LWFA and PWFA systems alike. At FACET, the proof-of-concept experiment 'E-210: Trojan Horse Plasma Wakefield Acceleration' has recently been approved and is in preparation. At the same time, various LWFA facilities are currently considered to host experiments aiming at stabilizing and boosting the electron bunch output quality via a trojan horse afterburner stage. Since normalized emittance and brightness can be improved by many orders of magnitude, the scheme is an ideal candidate for light sources such as free-electron-lasers and those based on Thomson scattering and betatron radiation alike.

  17. Basic Technology and Clinical Applications of the Updated Model of Laser Speckle Flowgraphy to Ocular Diseases

    Directory of Open Access Journals (Sweden)

    Tetsuya Sugiyama

    2014-08-01

    Full Text Available Laser speckle flowgraphy (LSFG allows for quantitative estimation of blood flow in the optic nerve head (ONH, choroid and retina, utilizing the laser speckle phenomenon. The basic technology and clinical applications of LSFG-NAVI, the updated model of LSFG, are summarized in this review. For developing a commercial version of LSFG, the special area sensor was replaced by the ordinary charge-coupled device camera. In LSFG-NAVI, the mean blur rate (MBR has been introduced as a new parameter. Compared to the original LSFG model, LSFG-NAVI demonstrates a better spatial resolution of the blood flow map of human ocular fundus. The observation area is 24 times larger than the original system. The analysis software can separately calculate MBRs in the blood vessels and tissues (capillaries of an entire ONH and the measurements have good reproducibility. The absolute values of MBR in the ONH have been shown to linearly correlate with the capillary blood flow. The Analysis of MBR pulse waveform provides parameters including skew, blowout score, blowout time, rising and falling rates, flow acceleration index, acceleration time index, and resistivity index for comparing different eyes. Recently, there have been an increasing number of reports on the clinical applications of LSFG-NAVI to ocular diseases, including glaucoma, retinal and choroidal diseases.

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

    Science.gov (United States)

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

    2016-01-01

    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) 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.

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

    Science.gov (United States)

    Ishibashi, W.; Fabian, A. C.

    2016-08-01

    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, suggesting a causal link between dust obscuration and blow-out. In this picture, AGN feedback and starburst phenomena are intrinsically coupled through the production of dust in supernova explosions, leading to a natural interpretation of the observed evolutionary path.

  20. 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.

  1. Emergency preparedness

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, J. [Key Safety and Blowout Control Corp., Sylvan Lake, AB (Canada)

    2001-07-01

    This presentation included several slides depicting well control and emergency preparedness. It provided information to help in pre-emergency planning for potential well control situations. Key Safety and Blowout Control Corp has gained experience in the Canadian and International well control industry as well as from the fires of Kuwait. The president of the company lectures on the complications and concerns of managers, wellsite supervisors, service companies, the public sector, land owners, government agencies and the media. The slides presented scenarios based on actual blowout recovery assignments and described what types of resources are needed by a well control team. The presentation addressed issues such as the responsibility of a well control team and what they can be expected to do. The issue of how government agencies become involved was also discussed. The presentation combines important information and descriptive images of personal experiences in fire fighting and well control. The emergency situations presented here demonstrate the need for a thorough understanding of preplanning for emergencies and what to expect when a typical day in the oil patch turns into a high stress, volatile situation. tabs., figs.

  2. 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.

  3. 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.

  4. 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...

  5. Exotic and intense lasers with orbital angular momentum for laser plasma interactions

    Science.gov (United States)

    Vieira, Jorge; Trines, Raoul; Alves, Eduardo; Fonseca, Ricardo; Mendonca, Jose T.; Norreys, Peter; Bingham, Robert; Silva, Luis

    2015-11-01

    Ultra-intense lasers have a multitude of applications in astrophysics, particle acceleration and radiation generation. Most advances were reached by exploiting a narrow set of fundamental laser properties, such as intensity and duration. The orbital angular momentum (OAM) is a new fundamental degree of freedom that can be exploited to reach new laser-plasma interactions regimes. Here, we explore the interaction between exotic laser pulses with orbital angular momentum, and plasmas resorting to theory and three-dimensional particle-in-cell OSIRIS simulations. We will then explore Raman scattering processes in plasmas, and show that these process can amplify OAM lasers to intensities beyond the PW, similarly to the case of a Gaussian laser. We also show a new set of selection rules for the creation of new, initially absent laser modes with well defined OAM. We show that these intense OAM laser pulses could then be used to drive strongly non-linear plasma waves in the doughnut blowout regime. We then show that the doughnut blowout regime can accelerate ring shaped electron and positron bunches.

  6. Preparing for the worst : Calgary startup brings emergency response into the digital age

    International Nuclear Information System (INIS)

    The potential danger of blowouts and oil spills is present in areas with high concentration of energy facilities and infrastructure. Ensuring that all possible measures have been taken to alert residents as early as possible is one way to alleviate fears of well blowouts, gas processing plant leaks, pipeline failures, or refinery or upgrader explosions. This article presented the GeoAlert, a high technology solution developed by Cell Bridge Communications Corporation to bring emergency response into the modern communications era. The features, benefits, and applications of GeoAlert were described. The program is a web-based emergency notification geographic information system application, that created a digital audit trail, and served as an internal communications and training platform, and had the potential to eliminate duplication among oil companies with overlapping jurisdictions. The system enabled companies to program emergency zones based on precise geographical co-ordinates and to use the system to proactively manage emergency response. It was concluded that the most visually striking feature of GeoAlert is its three-dimensional satellite mapping technology, which could display plumes as a purple-coloured initial isolation zone laid over designated emergency planning zones, moving in real-time while automatically identifying who should be notified and when. 1 fig.

  7. The role of three-dimensional computed tomography in the management of maxillofacial bone fractures

    International Nuclear Information System (INIS)

    The findings of three-dimensional computed tomography (3DCT) and two-dimensional computed tomography (2DCT) with helical CT scanning were compared for 21 patients with maxillofacial bone fractures. The results of this study suggest that the 3DCT evaluation can be divided into 3 groups. The first group, in which 3DCT is superior to 2DCT, includes severe complicated mid-face fractures, for example, tripod fractures and complicated maxillary bone fractures. The second group, in which 3DCT is equal to 2DCT, includes simple fractures, for example, nasal bone fractures and isolated zygomatic fractures. In this group, patients and their families could easily understand the nature of the fracture and clinical course shown by 3DCT as compared with conventional X-ray and 2DCT. The third group, in which 3DCT is inferior to 2DCT, includes blowout fractures. Although 3DCT does not provide additional information in blowout fractures, helical scanning permits clear observation of multiplanar images without artifacts arising from metal prostheses by excluding lower slices during image reconstruction. We conclude that 3DCT provides useful information, especially in regard to the extent of complex fracture lines, as in tripod fractures. (author)

  8. 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.

  9. State of the Arctic Environment

    International Nuclear Information System (INIS)

    The Arctic environment, covering about 21 million km2, is in this connection regarded as the area north of the Arctic Circle. General biological and physical features of the terrestrial and freshwater environments of the Arctic are briefly described, but most effort is put into a description of the marine part which constitutes about two-thirds of the total Arctic environment. General oceanography and morphological characteristics are included; e.g. that the continental shelf surrounding the Arctic deep water basins covers approximately 36% of the surface areas of Arctic waters, but contains only 2% of the total water masses. Blowout accident may release thousands of tons of oil per day and last for months. They occur statistically very seldom, but the magnitude underlines the necessity of an efficient oil spill contingency as well as sound safety and quality assurance procedures. Contingency plans should be coordinated and regularly evaluated through simulated and practical tests of performance. Arctic conditions demand alternative measures compared to those otherwise used for oil spill prevention and clean-up. New concepts or optimization of existing mechanical equipment is necessary. Chemical and thermal methods should be evaluated for efficiency and possible environmental effects. Both due to regular discharges of oil contaminated drilled cuttings and the possibility of a blowout or other spills, drilling operations in biological sensitive areas may be regulated to take place only during the less sensitive parts of the year. 122 refs., 8 figs., 8 tabs

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

    Science.gov (United States)

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

    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.

  11. 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.

  12. 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.

  13. 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...

  14. Studies of a hybrid Trojan Horse wakefield accelerator with high transformer ratio

    Science.gov (United States)

    Cook, Nathan; Bruhwiler, David; Hidding, Bernhard; Vay, Jean-Luc; Webb, Stephen

    2015-11-01

    Plasma wakefield acceleration uses relativistic high-charge electron bunches to generate a plasma blowout supporting intense electric fields for trapping and acceleration. Dramatic improvements in emittance, peak current and brightness are achievable through laser-controlled ionization in the plasma blowout, which is the premise of the Trojan Horse approach. The hybrid Trojan Horse concept extends this approach to use the output beam from a laser plasma accelerator to drive a Trojan Horse, resulting in a compact system that can produce higher brightness bunches with order-of-magnitude lower energy spread. We are exploring the use of multiple, shaped laser pulses to resonantly inject a shaped electron drive bunch. The resulting output bunch could generate wakes in PWFA or beam-driven dielectric structures with transformer ratios of 5 to 10 or larger. Hence, a hybrid Trojan Horse accelerator with bunch shaping may provide a compact source of nC bunches that can drive a variety of systems for studying high-gradient wakefields and lepton acceleration. Initial work will use previously simulated electron bunches from a laser plasma accelerator to drive the plasma wakefield stage. We present preliminary results from simulations using the parallel, particle-in-cell framework Warp. Work supported by the U.S. Department of Energy, Office of High Energy Physics, under Award Number DE-SC0013855.

  15. 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 ...

  16. Study on the characteristics of laminar lifted flames using plannar laser induced fluorescence technique

    Energy Technology Data Exchange (ETDEWEB)

    Lee, B. J. [Yeungnam Univ., Taegu (Korea, Republic of); Jung, S. H. [Seoul National University, Seoul (Korea, Republic of); Han, J. W. [Korea Research Institute of Standards and Science, Taejon (Korea, Republic of)

    1997-06-26

    Characteristics of the lifted flame which is generated by issuing of the fuel through the miniature nozzle, d=0.164 mm, are studied using the planar laser induced fluorescence technique. OH radical is excited on the Q{sub 1}(8) line of the A{sup 2}{Sigma} {sup +}<- X{sup 2}{Pi} (1,0) band transition(283.55 nm) and LIF signals are captured at the bands of (0,0) and (1,1) transition(306 {approx} 326) using the filters and ICCD camera. Hydroxyl radical(OH) profile for nozzle attached flame shows that OH radical populations at the flame sides and flame tip are larger than those at the base. But for the lifted flame (tribrachial flame) case, those are larger at the flame base than at the flame and flame sides. The OH radical is more dense near the center line of flame base at the blowing out. This fact proves the Chung and Lee`s blowout theory - blowout occurs when the flame is anchored at the flame axis. (author). 28 refs., 9 figs.

  17. Investigation of a transsonic slot cooling system for high-temperature gas turbine blades; Untersuchung einer transsonischen Schlitzkuehlung fuer Hochtemperaturgasturbinenschaufeln

    Energy Technology Data Exchange (ETDEWEB)

    Moser, S.

    2003-07-01

    The author investigated a slot cooling system with transsonic blowout of cooling air for high-temperature gas turbine blades. The method has the advantage that the cooling film is closer to the blade surface and the boundary layer at the blade wall is not interrupted even at high blowout rates. This way, the cooling film will mix less with the hot gas flow, and the cooling effect will last longer. The method is based on the subsonic Coanda effect and the supersonic Prandtl-Meyer effect, both of which result in attachment of the cooling film to a curved surface. The investigations and the optimisation were carried out using the experimental system, measuring instruments and software of the Institute of Thermal Turbo-Engines and Machine Dynamics. [German] In dieser Arbeit wird eine Schlitzkuehlung mit transsonischer Kuehlluftausblasung fuer Hochtemperaturgasturbinenschaufeln untersucht. Der Vorteil dieser Kuehlmethode ist, dass der entstehende Kuehlfilm besser an die Schaufeloberflaeche anliegt und die Grenzschicht an der Schaufelwand auch bei hohen Ausblasraten nicht durchstossen wird. Dies bewirkt ein geringeres Vermischen des Kuehlfilms mit der heissen Gasstroemung und somit ein laengeres Anhalten des Kuehlungseffektes. Man bedient sich dabei zweier in der Stroemungslehre bekannter Effekte, naemlich dem subsonischen Coanda Effekt und dem im Ueberschall auftretenden Prandtl-Meyer Effekt. Beide bewirken das Anlegen der Kuehlfilme an eine gekruemmte Oberflaeche. Mit Hilfe der am Institut fuer thermische Turbomaschinen und Maschinendynamik zur Verfuegung stehenden Versuchsanlagen, Messgeraete und Software wurde die Untersuchung bzw. Optimierung der transsonischen Schlitzkuehlung durchgefuehrt. (orig.)

  18. Dark matter halos and the M-\\sigma relation for supermassive black holes

    CERN Document Server

    Larkin, Adam C

    2016-01-01

    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 $R_e$ and velocity dispersions within $R_e$) to the properties of their dark-matter halos 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, $M_{\\rm{BH}}$, should then be connected to the dark-matter potential wells at the redshift $z_{\\rm{qso}}$ 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: $M_{\\rm{BH}}\\propto V^4_{\\rm{d,pk}}$, as could be expected if quasar-mode feedback were momentum-driven. For halos with a given $V_{\\rm{d,pk}}$ at a given $z_{\\rm{qso}}\\ge 0$, our model scaling relations give a typical stellar velocity dispersion $\\sigma_{\\rm{ap}}(R_e)$...

  19. Local Velocity Field Measurements towards Understanding Flame Stabilization of Turbulent Non-premixed Jet Flames in Vitiated Coflow

    Science.gov (United States)

    Ramachandran, Aravind; Mothe, Anirudh Reddy; Narayanaswamy, Venkateswaran

    2015-11-01

    Turbulent combustion of a non-premixed methane jet issuing into a vitiated coflow is being studied in our lab. Flame luminosity studies demonstrated three dominant characteristic flame motions - a stable flame base (Mode A), complete blowout (Mode B), and partial blowout followed by re-anchoring of the flame by autoignition kernels (Mode C). The experiments presented in this work focused on Mode A, and were carried out over a range of oxidizer temperatures, oxygen molefractions, and fuel jet Reynolds numbers. Measurements of 2-D velocity fields near the base of the lifted jet flame were obtained using Particle Image Velocimetry (PIV) with the objective to delineate the dominant mechanisms involved in the flame stabilization. Statistical analysis of these instantaneous velocity fields will be presented, which shows non-trivial contributions from autoignition kernels as well as edge flame propagation towards flame stabilization. The effect of vortices and high local strain rates was observed to produce local extinctions and destabilize the flame, indicating their role as precursors to (unstable) Mode B and Mode C motions. NSF Grant CBET-1511216.

  20. Methane release from pingo-like features across the South Kara Sea shelf, an area of thawing offshore permafrost

    Science.gov (United States)

    Serov, Pavel; Portnov, Alexey; Mienert, Jurgen; Semenov, Peter; Ilatovskaya, Polina

    2015-08-01

    The Holocene marine transgression starting at ~19 ka flooded the Arctic shelves driving extensive thawing of terrestrial permafrost. It thereby promoted methanogenesis within sediments, the dissociation of gas hydrates, and the release of formerly trapped gas, with the accumulation in pressure of released methane eventually triggering blowouts through weakened zones in the overlying and thinned permafrost. Here we present a range of geophysical and chemical scenarios for the formation of pingo-like formations (PLFs) leading to potential blowouts. Specifically, we report on methane anomalies from the South Kara Sea shelf focusing on two PLFs imaged from high-resolution seismic records. A variety of geochemical methods are applied to study concentrations and types of gas, its character, and genesis. PLF 1 demonstrates ubiquitously low-methane concentrations (14.2-55.3 ppm) that are likely due to partly unfrozen sediments with an ice-saturated internal core reaching close to the seafloor. In contrast, PLF 2 reveals anomalously high-methane concentrations of >120,000 ppm where frozen sediments are completely absent. The methane in all recovered samples is of microbial and not of thermogenic origin from deep hydrocarbon sources. However, the relatively low organic matter content (0.52-1.69%) of seafloor sediments restricts extensive in situ methane production. As a consequence, we hypothesize that the high-methane concentrations at PLF 2 are due to microbial methane production and migration from a deeper source.

  1. Beyond injection: Trojan horse underdense photocathode plasma wakefield acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Hidding, B.; Rosenzweig, J. B.; Xi, Y.; O' Shea, B.; Andonian, G.; Schiller, D.; Barber, S.; Williams, O.; Pretzler, G.; Koenigstein, T.; Kleeschulte, F.; Hogan, M. J.; Litos, M.; Corde, S.; White, W. W.; Muggli, P.; Bruhwiler, D. L.; Lotov, K. [Institut fuer Laser- und Plasmaphysik, Heinrich-Heine-Universitaet Duesseldorf 40225 Duesseldorf (Germany) and Particle Beam Physics Laboratory, Department for Physics and Astronomy, UCLA (United States); Particle Beam Physics Laboratory, Department for Physics and Astronomy, UCLA (United States); Institut fuer Laser- und Plasmaphysik, Heinrich-Heine-Universitaet Duesseldorf 40225 Duesseldorf (Germany); Stanford Linear Accelerator Center (United States); Max-Planck-Institut fuer Physik, Muenchen (Germany); Tech-X Corporation, Boulder, Colorado (United States) and 1348 Redwood Ave., Boulder, Colorado 80304 (United States); Budker Institute of Nuclear Physics SB RAS, 630090, Novosibirsk (Russian Federation) and Novosibirsk State University, 630090, Novosibirsk (Russian Federation)

    2012-12-21

    An overview on the underlying principles of the hybrid plasma wakefield acceleration scheme dubbed 'Trojan Horse' acceleration is given. The concept is based on laser-controlled release of electrons directly into a particle-beam-driven plasma blowout, paving the way for controlled, shapeable electron bunches with ultralow emittance and ultrahigh brightness. Combining the virtues of a low-ionization-threshold underdense photocathode with the GV/m-scale electric fields of a practically dephasing-free beam-driven plasma blowout, this constitutes a 4th generation electron acceleration scheme. It is applicable as a beam brightness transformer for electron bunches from LWFA and PWFA systems alike. At FACET, the proof-of-concept experiment 'E-210: Trojan Horse Plasma Wakefield Acceleration' has recently been approved and is in preparation. At the same time, various LWFA facilities are currently considered to host experiments aiming at stabilizing and boosting the electron bunch output quality via a trojan horse afterburner stage. Since normalized emittance and brightness can be improved by many orders of magnitude, the scheme is an ideal candidate for light sources such as free-electron-lasers and those based on Thomson scattering and betatron radiation alike.

  2. An application of dynamic CT for diagnosis of abnormal external ocular muscle movement

    International Nuclear Information System (INIS)

    To evaluate the movements of retrobulbar structures radiologically, we have developed a new technique called 'external ocular muscle movement CT' (EOM CT), in which dynamic CT scanning is performed while the patient performs controlled eye movements. This new technique was applied in one volunteer and 72 patients with external ophthalmoplegia due to orbital mass lesion, hyperthyroid ophthalmopathy, blowout fracture, and other retrobulbar lesions. EOM CT permits the assessment of extraocular muscle contraction in cases of blowout fracture, the evaluation of muscular contraction in hypertrophy of the extraocular muscles, and the diagnosis of adhesions between the extraocular muscles and intraorbital masses. Radiation dose to the lens from EOM CT was measured using a phantom and TLD, and was compared with that of conventional CT scanning with a 5 mm slice thickness. The dose to the lens from EOM CT was three times higher than that for conventional CT in axial scanning, but in the coronal section of the retrobulbar region, the dose to the lens from EOM CT decreases to one twelfth of that of conventional CT. EOM CT promises to be a powerful modality for functional evaluation of the extraocular muscles and other retrobulbar structures. (author)

  3. 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.

  4. Copiar o crear: La postmodernidad desde el cine de Michelangelo Antonioni y Brian de Palma Copy or Creation: Postmodernity from films by Michelangelo Antonioni and Brian de Palma

    Directory of Open Access Journals (Sweden)

    Inmaculada Murcia Serrano

    2009-07-01

    Full Text Available Utilizando dos películas como pretexto, Blow up de Michelangelo Antonioni y Blow-out de Brian de Palma, en este artículo se abordan distintas teorías postmodernas en relación al impacto de las nuevas tecnologías sobre la distinción metafísica y moderna entre esencia y apariencia. A la luz de los dos films, se estudian y valoran los conceptos de «simulación» y «simulacro», así como los presupuestos del pensamiento débil en relación a la desaparición tecnológica de la realidad.Using two movies as an excuse, Blow up by Michelangelo Antonioni and Blow-out by Brian de Palm, this article will approach different postmodern theories according to the impact of new technologies on the metaphysical and modern distinction between essence and appearance. In the light of both films, the concepts of «simulation» and «simulacra» will be studied, as well as the budgets of «weak thought» in relation to the technological disappearance of reality.

  5. 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

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

    International Nuclear Information System (INIS)

    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) develop a precise dewatering level control mechanism to insure a

  7. A non-linear theory for the bubble regime of plasma wake fields in tailored plasma channels

    CERN Document Server

    Thomas, Johannes; Pronold, Jari; Golovanov, Anton; Pukhov, Alexander

    2015-01-01

    We introduce a first full analytical bubble and blow-out model for a radially inhomogeneous plasma in a quasi-static approximation. For both cases we calculate the accelerating and the focusing fields. In our model we also assume a thin electron layer that surrounds the wake field and calculate the field configuration within. Our theory holds for arbitrary radial density profiles and reduces to known models in the limit of a homogeneous plasma. From a previous study of hollow plasma channels with smooth boundaries for laser-driven electron acceleration in the bubble regime we know that pancake-like laser pulses lead to highest electron energies [Pukhov et al, PRL 113, 245003 (2014)]. As it was shown, the bubble fields can be adjusted to balance the laser depletion and dephasing lengths by varying the plasma density profile inside a deep channel. Now we show why the radial fields in the vacuum part of a channel become defocussing.

  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. 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...

  10. All-inside ACL: retroconstruction controversies.

    Science.gov (United States)

    Lubowitz, James H

    2010-03-01

    All-inside anterior cruciate ligament reconstruction is controversial because the technique is new; as a result, evidence-based clinical outcome studies have yet to be published. The purpose of this article is to consider the following controversies (considered alphabetically): anatomy, biomechanics, biology, bioabsorbables, divergence of the femoral interference screw, expansion or widening of tunnels, fixation, future considerations, graft choice, the learning curve, technique, tensioning, and tibia blow-out fracture. The technique should be learned in stages. In the opinion of the author, the history of sports medicine and arthroscopy has been a progression toward less invasive techniques. In the future, all-inside anterior cruciate ligament reconstruction techniques should become more simple and reproducible, and clinical outcomes must be analyzed with long-term follow-up. PMID:20160626

  11. 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.

  12. 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.

  13. Effect of the frequency chirp on laser wakefield acceleration

    CERN Document Server

    Pathak, V B; Fonseca, R A; Silva, L O

    2011-01-01

    The role of laser frequency chirps in the laser wakefield accelerator is examined. We show that in the linear regime, the evolution of the laser pulse length is affected by the frequency chirp, and that positive (negative) chirp compresses (stretches) the laser pulse, thereby increasing (decreasing) the peak vector potential and wakefield amplitude. In the blowout regime, the frequency chirp can be used to fine tune the localized etching rates at the front of the laser. In our simulations, chirped laser pulses can lead to 15% higher self-trapped electrons, and 10% higher peak energies as compare to the transform-limited pulse. Chirps may be used to control the phase velocity of the wake, and to relax the self-guiding conditions at the front of the laser. Our predictions are confirmed by multi-dimensional particle-in-cell simulations with OSIRIS.

  14. Management of necrotic neck wounds with a sandwich pectoralis myocutaneous flap

    International Nuclear Information System (INIS)

    A modified pectoralis major myocutaneous flap was used to stabilize necrotic neck wounds rapidly in irradiated patients. The flap was a sandwich flap that included an overlying parasternal pectoral skin paddle for pharyngeal reconstruction, the pectoralis muscle for carotid protection, and a meshed skin graft applied to the undersurface of the muscle to replace cervical skin. This flap has been used to reconstruct seven patients with severe wound necrosis from pharyngeal fistula and infection. All patients had carotid exposure in the infected wound. Reconstruction in all patients accomplished restoration of pharyngeal continuity, carotid protection, and cervical skin replacement. Some patients required more than one procedure for closure. There were no carotid blowouts in any of the patients. This technique enables the head and neck surgeon to stabilize these contaminated wounds rapidly and to reconstruct complex defects of the pharynx and cervical skin

  15. 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.

  16. Characteristics of turbulent nonpremixed jet flame in cross air flow

    International Nuclear Information System (INIS)

    An experimental study on the characteristics of stability of propane turbulent nonpremixed jet flames discharged normal to air free-streams with uniform velocity profile is conducted. Experimental observations are focused on the flame shape, the stability considering two kinds of flame, lift-off distance,and the flame length according to velocity ratio. In order to investigate the mixing structure of the flame base at the lower limit, we employ the RMS technique and measure the species consent ration by a gas chromatography. In the results of the stability curve and lifted flame, it is found that the dependency of nozzle diameter is closely related to the large-scale vortical structure representing counter-rotating vortices pair. Also, the detailed discussion on the phenomenon of blowout due to this large vortical motion, is provided

  17. 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.

  18. 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.

  19. 蒸汽驱井下作业技术研究%Steam flooding down-hole operation

    Institute of Scientific and Technical Information of China (English)

    陈东

    2016-01-01

    锦45块稠油蒸汽驱井主要存在汽窜井喷、H2S中毒、高温伤害等风险,给井下作业带来极大的难度,严重影响和制约了安全生产工作。相关人员经过探索实践,研究出了一系列井下作业技术,为蒸汽驱作业提供了经验。%Accidents, such as well blow-out caused by steam channeling, hydrogen sulfide intoxication and high temperature hazard, may occur in heavy oil steam flooding well in Jin 45 block, which bring great difficulties to down-hole operation and delay the safe operation. This article describes a series of down-hole operation technologies which are developed for steam flooding.

  20. Characterization of degeneration process in combustion instability based on dynamical systems theory.

    Science.gov (United States)

    Gotoda, Hiroshi; Okuno, Yuta; Hayashi, Kenta; Tachibana, Shigeru

    2015-11-01

    We present a detailed study on the characterization of the degeneration process in combustion instability based on dynamical systems theory. We deal with combustion instability in a lean premixed-type gas-turbine model combustor, one of the fundamentally and practically important combustion systems. The dynamic behavior of combustion instability in close proximity to lean blowout is dominated by a stochastic process and transits to periodic oscillations created by thermoacoustic combustion oscillations via chaos with increasing equivalence ratio [Chaos 21, 013124 (2011); Chaos 22, 043128 (2012)]. Thermoacoustic combustion oscillations degenerate with a further increase in the equivalence ratio, and the dynamic behavior leads to chaotic fluctuations via quasiperiodic oscillations. The concept of dynamical systems theory presented here allows us to clarify the nonlinear characteristics hidden in complex combustion dynamics. PMID:26651761

  1. Assessment of near-surface dissolution at and near the Waste Isolation Pilot Plant (WIPP), southeastern New Mexico

    International Nuclear Information System (INIS)

    The area at and near the WIPP site was examined for evidence of karst development on the geomorphic surface encompassing the site. Certain surficial depressions of initial concern were identified as blowouts in sand dune fields (shallow features unrelated to karstification). An ancient stream system active more than 500,000 yr ago contained more water than any system since. During that time (Gatuna, Middle Pleistocene), many karst features such as Clayton Basin and Nash Draw began to form in the region. Halite was probably dissolved from parts of the Rustler Formation at that time. Dissolution of halite and gypsum from intervals encountered in Borehole WIPP-33 west of the WIPP site occurred during later Pleistocene time (i.e., <450,000 yr ago). However, there is no evidence of active near-surface dissolution within a belt to the east of WIPP-33 in the vicinity of the WIPP shaft. 26 refs., 11 figs., 1 tab

  2. 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 examined and evaluated. It is found that both diamond turned DOE’s in zinc sulphide and multilevel etched DOE’s (Diffractive Optical Elements) in fused silica have a good performance. Welding with multiple beams in a butt joint configuration has been tested. Results are presented, showing it has...... 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....

  3. Dragon slayers: Canadian wild well tamers among the best in world

    Energy Technology Data Exchange (ETDEWEB)

    Polczer, S.

    1999-10-01

    The development of oil well fire fighting techniques, and some of the more famous fires in the Alberta oil patch such as the Atlantic 3 blowout at Leduc Alberta in 1955 and the Lodgepole fire in 1982, are described, leading up to a discussion of the outstanding work done by Canadian oilfield fire fighters in Kuwait. During the Gulf War in 1991 the retreating Iraqi forces blew up 732 oil wells, sparking the largest oilfield emergency in history. Fire fighters from the Drayton Valley, Alberta, firm of 'Safety Boss' snuffed out 180 wells in 200 days, establishing Canadian oil well fire fighters as among the best in the world. Since then, the company was called upon to assist in extinguishing fires at the Tupras Refinery following the earthquake in Turkey in the summer of 1999, and at the Hub Oil Ltd. fire in southeast Calgary, just a week prior to the earthquake in Turkey. 2 photos.

  4. 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)

  5. Deep-sea oil plume enriches indigenous oil-degrading bacteria.

    Science.gov (United States)

    Hazen, Terry C; Dubinsky, Eric A; DeSantis, Todd Z; Andersen, Gary L; Piceno, Yvette M; Singh, Navjeet; Jansson, Janet K; Probst, Alexander; Borglin, Sharon E; Fortney, Julian L; Stringfellow, William T; Bill, Markus; Conrad, Mark E; Tom, Lauren M; Chavarria, Krystle L; Alusi, Thana R; Lamendella, Regina; Joyner, Dominique C; Spier, Chelsea; Baelum, Jacob; Auer, Manfred; Zemla, Marcin L; Chakraborty, Romy; Sonnenthal, Eric L; D'haeseleer, Patrik; Holman, Hoi-Ying N; Osman, Shariff; Lu, Zhenmei; Van Nostrand, Joy D; Deng, Ye; Zhou, Jizhong; Mason, Olivia U

    2010-10-01

    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 γ-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. PMID:20736401

  6. Nuclear reactions in palladium saturated with deuterium and rhenium in dense deuterium gas under irradiation by γ-quanta of continuous spectrum with boundary 23 MeV energy

    International Nuclear Information System (INIS)

    Elemental composition studies of Pd and Re samples irradiated by γ-quanta in dense deuterium gas of continuous spectrum with the boundary 23 MeV energy were carried out. Significant anomalies in the structure and chemical composition are obtained. Considerable changes are observed at both ends of the Pd and Re wire as blowouts of molten metal with complex element composition, resembling congealed Solar protuberances. The cracky surfaces of the Pd and Re wires were covered with 1-2 m particles predominantly composed of rhenium oxide RexCy. These particles had been crystallized into small hexagonal crystallites near the cracks in the palladium. The rhenium surface was covered by a thick layer with a large carbon concentration. A short description of the phenomenological model of nuclear reactions leading to the observed anomalies is presented

  7. Numerical investigation of gas flow through blast furnace shaft with designed layered structure of ore and coke burdens

    Energy Technology Data Exchange (ETDEWEB)

    Qing, G.L.; Ma, L.; Zhang, X.S.; Zhou, J.L.; Kuwabara, M.

    2010-10-15

    Detailed comments on governing equations and boundary conditions on which numerical results of gas flow in porous media should rely are presented. Numerical results are shown for the gas flow through a large blast furnace with designed layered structure of burdens. Not only the effects of radial and vertical distributions of resistance to flow but also the effects of different top profiles of burden, such as V-, M-shapes and V-shape with a side terrace, on the resultant gas flow are discussed in relation to the properties of burden, such as repose angle, particle size, voidage and different charging sequence. For the gas flow in a coaxial annulus bed, which is expected to appear in the lower part of blast furnace during a start-up or a blow-out operation, numerical predictions are compared with analytical ones based on a simple yet convenient gas flow model.

  8. 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.

  9. Quality assessment of clinical computed tomography

    Science.gov (United States)

    Berndt, Dorothea; Luckow, Marlen; Lambrecht, J. Thomas; Beckmann, Felix; Müller, Bert

    2008-08-01

    Three-dimensional images are vital for the diagnosis in dentistry and cranio-maxillofacial surgery. Artifacts caused by highly absorbing components such as metallic implants, however, limit the value of the tomograms. The dominant artifacts observed are blowout and streaks. Investigating the artifacts generated by metallic implants in a pig jaw, the data acquisition for the patients in dentistry should be optimized in a quantitative manner. A freshly explanted pig jaw including related soft-tissues served as a model system. Images were recorded varying the accelerating voltage and the beam current. The comparison with multi-slice and micro computed tomography (CT) helps to validate the approach with the dental CT system (3D-Accuitomo, Morita, Japan). The data are rigidly registered to comparatively quantify their quality. The micro CT data provide a reasonable standard for quantitative data assessment of clinical CT.

  10. 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.

  11. Isolated inferior rectus muscle rupture after blunt orbital trauma

    Science.gov (United States)

    Tomasetti, Patrick; Metzler, Philipp; Jacobsen, Christine

    2013-01-01

    A 44-year-old man was referred to our department with diplopia, periorbital swelling and haematoma of the left eye after orbital trauma due to a punch. During the examination, mild enophthalmos, hypertropia and a total absence of infraduction were observed. An orbital computed tomography (CT) scan demonstrated a left orbital floor blow-out fracture, with caudal herniation of periorbital fat and rectus inferior muscle. Repair was performed under total anaesthesia with placement of a Titan mesh. The following days were marked by the persistence of diplopia without improvement of infraduction. A postoperative, 0.5 mm CT scan highlighted a complete rupture of the inferior rectus muscle, not seen before operation, by a 1.0 mm-sliced CT. In this case, orthoptic therapy was undertaken with good results after 6 months and without need of a second repair. PMID:24963904

  12. 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.

  13. 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.

  14. 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.

  15. Development of a variable quench pressure relief valve for superconducting magnet system

    Science.gov (United States)

    Kimura, N.; Ohhata, H.; Okamura, T.; Makida, Y.; Yoshida, H.

    2011-08-01

    A new variable quench pressure relief valve (VQRV) for a superconducting magnet system has been developed at the High Energy Accelerator Research Organization (KEK). The VQRV is designed that the setting of the blowout pressure can be freely controlled and be maintenance-free for long-term operation. A prototype VQRV was tested under a high radiation environment up to 2.5 MGy. The heat load of 1.5 W at 4.2 K and a seat leakage rate of 4.5 × 10-7 kg/s at 4.2 K of the VQRV were confirmed. It has enough performances for the cryogenic system operation in the Japan Proton Accelerator Research Complex (J-PARC) neutrino beam line. The design and test results of the VQRV are described in this technical note.

  16. 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.

  17. 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)。

  18. 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.

  19. Kuwait summons more fire fighting teams

    International Nuclear Information System (INIS)

    Kuwait is calling in more muscle to help kill its wild wells. This paper reports on the latest action in Kuwait, the leasing of well control contracts to Abel Engineering/Well Control Inc., Houston, and China Petroleum Engineering Construction Co. (CPEC). Abel is the sixth North American well control company called to the scene, while CPEC is the first summoned from the East. In addition, the service responsible for combating well fires and blowouts in the U.S.S.R.'s Azerbaijan oil fields signed an agreement with Kuwait's government, apparently involving a contract valued at more than $100 million, to extinguish fires at 150 Kuwaiti wells, reported Eastern Bloc Energy, a publication of Eastern Bloc Research Ltd., Newton Kyme, U.K. More help likely is on the way

  20. Dragon slayers: Canadian wild well tamers among the best in world

    International Nuclear Information System (INIS)

    The development of oil well fire fighting techniques, and some of the more famous fires in the Alberta oil patch such as the Atlantic 3 blowout at Leduc Alberta in 1955 and the Lodgepole fire in 1982, are described, leading up to a discussion of the outstanding work done by Canadian oilfield fire fighters in Kuwait. During the Gulf War in 1991 the retreating Iraqi forces blew up 732 oil wells, sparking the largest oilfield emergency in history. Fire fighters from the Drayton Valley, Alberta, firm of 'Safety Boss' snuffed out 180 wells in 200 days, establishing Canadian oil well fire fighters as among the best in the world. Since then, the company was called upon to assist in extinguishing fires at the Tupras Refinery following the earthquake in Turkey in the summer of 1999, and at the Hub Oil Ltd. fire in southeast Calgary, just a week prior to the earthquake in Turkey. 2 photos

  1. 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.

  2. Full core simulation of Loss of Coolant transients in an AP600 reactor using COBRA

    International Nuclear Information System (INIS)

    Core transients have been calculated with full core and single channel models by COBRA-IV-I and with single channel model by RELAPS/MOD2. From the single channel simulations, it has been found that for transients where the rate of change of the conditions is moderate to rapid, like in a small LOCA, there is an excellent agreement between the results of the two codes. For rapid transients as , in a large LOCA the. agreement is less favorable, although qualitatively similar results are obtained. Result obtained when using the more accurate full core model are generally different than that obtained when a SC model is used. Full core simulation indicates that the coolant which enters the core after the blowout flows mainly through the.cooler channels and bypasses the hot channels cools them only by heat conduction. This kind of simulation is essential for calculation and verification of the hot channel factor. (authors); 6 refs., 5 figs

  3. Effect of flame-tube head structure on combustion chamber performance

    Science.gov (United States)

    Gu, Minqqi

    1986-01-01

    The experimental combustion performance of a premixed, pilot-type flame tube with various head structures is discussed. The test study covers an extensive area: efficiency of the combustion chamber, quality of the outlet temperature field, limit of the fuel-lean blowout, ignition performance at ground starting, and carbon deposition. As a result of these tests, a nozzle was found which fits the premixed pilot flame tube well. The use of this nozzle optimized the performance of the combustion chamber. The tested models had premixed pilot chambers with two types of air-film-cooling structures, six types of venturi-tube structures, and secondary fuel nozzles with two small spray-cone angles.

  4. Rigid finite element method in analysis of dynamics of offshore structures

    Energy Technology Data Exchange (ETDEWEB)

    Wittbrodt, Edmund [Gdansk Univ. of Technology (Poland); Szczotka, Marek; Maczynski, Andrzej; Wojciech, Stanislaw [Bielsko-Biala Univ. (Poland)

    2013-07-01

    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 pipe-laying operations taking active reel drive into account are shown.

  5. Quasars Are Not Light-Bulbs: Testing Models of Quasar Lifetimes with the Observed Eddington Ratio Distribution

    CERN Document Server

    Hopkins, Philip F

    2008-01-01

    We use the observed distribution of Eddington ratios as a function of supermassive black hole (BH) mass to constrain models of AGN lifetimes and lightcurves. Given the observed AGN luminosity function, a model for AGN lifetimes (time above a given luminosity) translates directly to a predicted Eddington ratio distribution. Models for self-regulated BH growth, in which feedback produces a 'blowout' decay phase after some peak luminosity (shutting down accretion) make specific predictions for the lifetimes distinct from those expected if AGN are simply gas starved (without feedback) and very different from simple phenomenological 'light bulb' models. Present observations of the Eddington ratio distribution, spanning 5 decades in Eddington ratio, 3 in BH mass, and redshifts z=0-1, agree with the predictions of self-regulated models, and rule out 'light-bulb', pure exponential, and gas starvation models at high significance. We compare the Eddington ratio distributions at fixed BH mass and fixed luminosity (both ...

  6. 眼眶爆裂性骨折(附22例报告)

    Institute of Scientific and Technical Information of China (English)

    曲道飞; 戚颖; 曹馨元; 齐屏; 张小平

    2006-01-01

    眼眶爆裂性骨折是眶部挫伤所致的眶壁骨折,眶缘完整,软组织嵌顿以及典型临床症状的一种单纯的眼眶外伤病症。Mackenzie(1844)首先提出,Smith和Regan(1957)命名为爆裂性骨折(blowout fracture)。由于眼眶爆裂性骨折可引起一系列眼部并发症,甚至失明,故应引起广大眼科医生的高度重视。现将我院眼科自1995年至今遇到的22例眼眶爆裂性骨折病人的诊治情况报告如下。

  7. Supernovae and Their Expanding Blast Waves during the Early Evolution of Galactic Globular Clusters

    Science.gov (United States)

    Tenorio-Tagle, Guillermo; Muñoz-Tuñón, Casiana; Silich, Sergiy; Cassisi, Santi

    2015-11-01

    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 ≥ 106 M⊙), 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.

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

    International Nuclear Information System (INIS)

    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.

  9. A Model for Stealth Coronal Mass Ejections

    Science.gov (United States)

    Lynch, Benjamin J.; Masson, Sophie; Li, Yan; DeVore, C. Richard; Luhmann, Janet; Antiochos, Spiro K.; Fisher, George H.

    2016-05-01

    Stealth coronal mass ejections (CMEs) are events in which there are almost no observable signatures of the CME eruption in the low corona but often a well-resolved slow flux rope CME observed in the coronagraph data. We present results from a three-dimensional numerical magnetohydrodynamics (MHD) simulation of the 2008 June 1-2 slow streamer blowout CME that Robbrecht et al. [2009] called “the CME from nowhere.” We model the global coronal structure using a 1.4 MK isothermal solar wind and a low-order potential field source surface representation of the Carrington Rotation 2070 magnetogram synoptic map. The bipolar streamer belt arcade is energized by simple shearing flows applied in the vicinity of the helmet streamer’s polarity inversion line. The slow expansion of the energized helmet-streamer arcade results in the formation of a radial current sheet. The subsequent onset of expansion-driven flare reconnection initiates the stealth CME while gradually releasing ~1.5E+30 erg of stored magnetic energy over the 20+ hour eruption duration. We show the energy flux available for flare heating and flare emission during the eruption is approximately two orders of magnitude below the energy flux required to heat the ambient background corona, thus confirming the “stealth” character of the 2008 June 1-2 CME’s lack of observable on disk signatures. We also present favorable comparisons between our simulation results and the multi-viewpoint SOHO-LASCO and STEREO-SECCHI coronagraph observations of the pre-eruption streamer structure and the initiation and evolution of the stealth streamer blowout CME.

  10. 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.

  11. Some observations on plasma-assisted combustion enhancement using dielectric barrier discharges

    Energy Technology Data Exchange (ETDEWEB)

    Tang Jie; Zhao Wei; Duan Yixiang, E-mail: yduan@scu.edu.cn, E-mail: yxd@opt.ac.cn [State Key Laboratory of Transient Optics and Photonics, Xi' an Institute of Optics and Precision Mechanics of CAS, Xi' an (China)

    2011-08-15

    We explore an effective way to promote propane combustion by applying a plasma discharge for efficiency enhancement. A coaxial-cylinder, dielectric barrier discharge is used to activate propane and air before they are mixed with each other and ignited for combustion. The characteristics of the combustion flame are well studied and evaluated by varying various operational parameters. It is found that the combustion process can be enhanced by applying a plasma on either the propane or air stream, and the combustion stability is found to be somewhat sensitive to the lean burning conditions and confined to a relatively narrow operating window. The temperature and spectrum of the flame in the main combustion zone are investigated with a 4 W plasma in the on or off state. The main components are identified, and the possible physical and chemical reaction mechanisms are discussed. A comparative analysis of these spectra and temperatures obtained in the main flame suggests that the energy generated from the 4 W plasma is partially used to heat the reaction gases in the flame, and another part of the energy is used to increase the luminosity, especially for activation of air. We also observe that combustion of high flow rate propane and/or air requires more discharge energy density under certain conditions. A comparison of combustion enhancement through different activation methods in flame blowout tests shows that reactive species derived from activation of air play a more critical role in the blowout limit of propane combustion flame than those generated by activation of propane at low equivalence ratio and propane flow.

  12. Numerical and experimental analysis of factors leading to suture dehiscence after Billroth II gastric resection.

    Science.gov (United States)

    Cvetkovic, Aleksandar M; Milasinovic, Danko Z; Peulic, Aleksandar S; Mijailovic, Nikola V; Filipovic, Nenad D; Zdravkovic, Nebojsa D

    2014-11-01

    The main goal of this study was to numerically quantify risk of duodenal stump blowout after Billroth II (BII) gastric resection. Our hypothesis was that the geometry of the reconstructed tract after BII resection is one of the key factors that can lead to duodenal dehiscence. We used computational fluid dynamics (CFD) with finite element (FE) simulations of various models of BII reconstructed gastrointestinal (GI) tract, as well as non-perfused, ex vivo, porcine experimental models. As main geometrical parameters for FE postoperative models we have used duodenal stump length and inclination between gastric remnant and duodenal stump. Virtual gastric resection was performed on each of 3D FE models based on multislice Computer Tomography (CT) DICOM. According to our computer simulation the difference between maximal duodenal stump pressures for models with most and least preferable geometry of reconstructed GI tract is about 30%. We compared the resulting postoperative duodenal pressure from computer simulations with duodenal stump dehiscence pressure from the experiment. Pressure at duodenal stump after BII resection obtained by computer simulation is 4-5 times lower than the dehiscence pressure according to our experiment on isolated bowel segment. Our conclusion is that if the surgery is performed technically correct, geometry variations of the reconstructed GI tract by themselves are not sufficient to cause duodenal stump blowout. Pressure that develops in the duodenal stump after BII resection using omega loop, only in the conjunction with other risk factors can cause duodenal dehiscence. Increased duodenal pressure after BII resection is risk factor. Hence we recommend the routine use of Roux en Y anastomosis as a safer solution in terms of resulting intraluminal pressure. However, if the surgeon decides to perform BII reconstruction, results obtained with this methodology can be valuable. PMID:25201585

  13. 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

  14. 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.

  15. South Arne field development: an environmental impact assessment of oil spills

    International Nuclear Information System (INIS)

    The South Arne field being developed by Amerada Hess A/S is located in 60 m water depth approximately 200 km from the Danish mainland, in block 5604/29 of the Danish sector of the North Sea. As part of the development of the field, a comprehensive environmental impact assessment has been carried out, including the assessment of the impact from oil spills. The Danish authorities required that a 'worst case' oil spill be chosen as the basis for the assessment on birds and aquatic organisms including plankton, fish eggs and larvae and benthos. A well blow-out at the surface was chosen as the worst case for the impact on birds, and a seabed blow-out for aquatic organisms. The oil spill modelling was carried out with the DEEPBLOW, SLIKMAP and OSCAR models from SINTEF. The modelling identified environmentally sensitive areas which could potentially be influenced by an oil spill. These included the Dogger Bank, western Skagerrak, south-western Norwegian Trench, the eastern German Bight and the Wadden Sea. Historical meteorological and hydrodynamic scenarios were chosen from a long period of records to ensure that the plume passed through the environmentally sensitive resource areas. For birds, a scan of the literature and available databases was made to determine the numbers and species of birds in the areas swept by the surface slick, the number of fatalities was estimated and finally the recovery time for each species population was estimated. The impact on aquatic organisms was estimated using the predicted environmental concentration/predicted no effect concentration (PEC/PNEC) method of the CHARM model. This method is normally applied to continuous discharges, but here has been used to estimate the impact of a transient pollution cloud resulting from an oil spill. (Author)

  16. The gaseous environments of quasars: outflows, feedback & cold mode accretion

    Science.gov (United States)

    Chen, Chen

    2016-01-01

    We are interested in the early stages of massive galaxy formation at high redshifts, when cold mode accretion and outflows that drive galaxy-scale blowouts and feedback are expected to occur. It is quite possible that infall (e.g. cold mode accretion) and outflow (e.g. a blowout) occur together, leading to complex gas structures. We are conducting a study of rich complexes of narrow CIV absorption lines to find direct evidence for cold mode accretion and gaseous fragments shredded and dispersed by powerful outflows. Study of these rich complexes will provide us critical information of gas, such as velocity, ionization, metallicity, column density, kinetic energy, etc. The information could help us to understand the gas origins. We search SDSS, VLT and Keck archives for quasars with complex multi-component CIV systems or/and strong infalling systems. We obtain particular interesting results for the quasar Q0119-046. The spectra show rich infalling and partial covering complexes. The electron density of the gas is ~103.4 cm-3, and the gas is at a distance ~3.6 kpc from the central source. The gas is metal poor and seems to be infalling at the speed ~70 km/s into the galaxy. And it appears to partially cover the continuum source, requiring absorber size scales less than 0.01 pc. This result for very small clouds on galactic ($>$ kpc) scales is unusual but not unprecedented. It may provide evidence that the clouds are fragments from a shredded cloud, dispersed by an unseen high-speed quasar-driven outflow.

  17. HERSCHEL-RESOLVED OUTER BELTS OF TWO-BELT DEBRIS DISKS AROUND A-TYPE STARS: HD 70313, HD 71722, HD 159492, AND F-TYPE: HD 104860

    International Nuclear Information System (INIS)

    We present dual-band Herschel/Photodetector Array Camera and Spectrometer imaging for four stars whose spectral energy distributions (SEDs) suggest two-ring disk architectures that mirror that of the asteroid-Kuiper Belt geometry of our own solar system. The Herschel observations at 100 μm spatially resolve the cold/outer-dust component for each star-disk system for the first time, finding evidence of planetesimals at >100 AU, i.e., a larger size than assumed from a simple blackbody fit to the SED. By breaking the degeneracy between the grain properties and the dust's radial location, the resolved images help constrain the dust grain-size distribution for each system. Three of the observed stars are A-type and one solar-type. On the basis of the combined Spitzer/IRS+MIPS (5-70 μm), the Herschel/PACS (100 and 160 μm) dataset, and under the assumption of idealized spherical grains, we find that the cold/outer belts of the three A-type stars are well fit with a mixed ice/rock composition rather than pure rocky grains, while the debris around the solar-type star is consistent with either rock or ice/rock grains. For the solar-type star HD 104860, we find that the minimum grain size is larger than expected from the threshold set by radiative blowout. The A-type stars HD 71722 and HD 159492, on the other hand, require minimum grain sizes that are smaller than blowout for inner- and outer-ring populations. In the absence of spectral features for ice, we find that the behavior of the continuum can help constrain the composition of the grains (of icy nature and not pure rocky material) given the Herschel-resolved locations of the cold/outer-dust belts

  18. 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.

  19. Local space air conditioning by covering with a plane jet. Part 1. Basic characteristics of heating in model chamber. Kukimaku riyo ni yoru kyokusho kukan kucho. 1. Onfunryu wo mochiita danboji no kihon tokusei (mokei jikken)

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, N. (Shinryo Corp., Tokyo (Japan)); Kubota, H.; Ijichi, T.; Kurosawa, K.; Yoshida, Y.; Hanaoka, Y. (Muroran Institute of Technology, Hokkaido (Japan))

    1994-05-25

    It is intended to use a space closed by an air film (vortex region) as a utilization space, and air-condition the space locally. The discussed method utilizes a phenomenon that plane jet in a semi-closed space deposits on a floor as a result of the Coanda effect. The Coanda effect, however, may not appear with warm jet during room heating. A discussion was given to derive the limit of the effect, and elucidated the temperature characteristics of the vortex region when the space was with and without obstacles. When the effect does not develop, the buoyancy of the warm jet in the horizontal direction supersedes static pressure drop generated by attracting flow rate of the flow. The experiment proposes the limiting condition of the jet deposition as K = Ar (Hs/h) [sup 3/2] (where Ar is an Archimedian number, Hs is a vertical distance from the floor to the center of the air outlet, and h is the air outlet width). The distance for the warm jet to deposit on the floor is constant irrespective of the air blow-out velocity and the blow-out temperature difference, where a relation of Ls/Hs [approx] 1.56 may be established. The temperature in the vortex region where there are no obstacles on the floor is a function of height and width of the air outlet, and that for where obstacles exist is expressed as a function of the obstacle installing distance and the outlet width. 3 refs., 13 figs., 1 tab.

  20. Hazards and prevention of fluky mind in well-control operation%井控过程中侥幸心理的危害与预防

    Institute of Scientific and Technical Information of China (English)

    冯数玖

    2014-01-01

    随着石油工业的发展,井喷失控的危害逐渐被认识到,预防井喷成为钻井工作的头等大事。钻井井控设备愈加完善,使得井控工作的薄弱环节表现在人为意识上,侥幸心理已经成为井控过程中的巨大安全隐患。本文详细分析了侥幸心理的表现形式和危害,研究了预防侥幸心理的方法,提出自动化和智能化钻井技术与互联网信息处理技术的完美结合,可以全面监控钻井工作,防止井喷失控事故的发生。%With the development of petroleum industry, serious harm of Blowout is gradually known by human, and the well-control precaution become the first importance of drilling work.Compared with the excellent BOP equip-ments, the people's action sometimes comes out in a weak situation.Based on analyses of danger and its character-istics induced by fluky mind, some methods to prevent fluky mind are proposed, and it is emphasized that thor-oughly combination between the Drilling automatic & intelligence and Information Processing Internet can compre-hensively monitor the drilling program and forbid Blow-out occurrence.

  1. Effects of Fuel Composition on Combustion Stability and NO X Emissions for Traditional and Alternative Jet Fuels

    Science.gov (United States)

    Vijlee, Shazib Z.

    Synthetic jet fuels are studied to help understand their viability as alternatives to traditionally derived jet fuel. Two combustion parameters -- flame stability and NOX emissions -- are used to compare these fuels through experiments and models. At its core, this is a fuels study comparing how chemical makeup and behavior relate. Six 'real', complex fuels are studied in this work -- four are synthetic from alternative sources and two are traditional from petroleum sources. Two of the synthetic fuels are derived from natural gas and coal via the Fischer Tropsch catalytic process. The other two are derived from Camelina oil and tallow via hydroprocessing. The traditional military jet fuel, JP8, is used as a baseline as it is derived from petroleum. The sixth fuel is derived from petroleum and is used to study the effects of aromatic content on the synthetic fuels. The synthetic fuels lack aromatic compounds, which are an important class of hydrocarbons necessary for fuel handling systems to function properly. Several single-component fuels are studied (through models and/or experiments) to facilitate interpretation and understanding. The flame stability study first compares all the 'real', complex fuels for blowout. A toroidal stirred reactor is used to try and isolate temperature and chemical effects. The modeling study of blowout in the toroidal reactor is the key to understanding any fuel-based differences in blowout behavior. A detailed, reacting CFD model of methane is used to understand how the reactor stabilizes the flame and how that changes as the reactor approaches blowout. A 22 species reduced form of GRI 3.0 is used to model methane chemistry. The knowledge of the radical species role is utilized to investigate the differences between a highly aliphatic fuel (surrogated by iso-octane) and a highly aromatic fuel (surrogated by toluene). A perfectly stirred reactor model is used to study the chemical kinetic pathways for these fuels near blowout. The

  2. 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

  3. 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

  4. 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

  5. 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

  6. Influence of thermally and externally induced vortices on the electrical transport in YBCO-films; Einfluss thermisch und extern induzierter Vortices auf den elektrischen Transport in YBCO-Filmen

    Energy Technology Data Exchange (ETDEWEB)

    Skwirblies, Sven

    2013-08-15

    This work investigates the dynamic conductivity and the critical current of superconductive 50nm to 600nm c-axes orient thin YBCO-films on MgO-substrate. The investigation is done by temperature, field, frequency and amplitude dependent susceptibility measurements χ(T, H{sub dc}, f, H{sub ac}) with a commercial SQUID-magnetometer. The main subject of this work is to investigate the influence of vortices on the superconductive properties of YBCO-films. Therefore frequency dependent magnetization measurements will be done in external zero fields to characterize thermal effects only. The dynamic conductivity, gained out of the magnetization measurements by inversion, can be described for all films by a coherent, frequency dependent 3D-XY area below the critical temperature T{sub c} and an incoherent Ginzburg-Landau (GL) similar area in the temperature range from T{sub c} to T{sub 0}. The crossover between these both areas is identifying by the blow-out of Vortex-loops at the blow-out temperature T{sub b} and shows a film thickness and frequency independent inverse kinetic inductance of L{sub k}{sup -1}(T{sub b}) = 35(5)nH{sup -1}. This universal Value is found up to the highest applied field of 10 kOe. It shows up that the starting of superconductivity in the frequency dependent GL-area is linked to the creation of exact one vortex-kernal. This behavior applies to higher fields too. The stability of this effect will be explained by the grain borders of the granularly YBCO-structured films with a local critical field H{sub g}(d{sub g}) of the grains. The critical currents will be extracted out of the magnetization measurements by an here explained experimental method and show the 3D-XY behavior below T{sub c} too. By fitting the deep temperature area of the critical current, the mean-field temperature T{sub 0} could be extracted. The vanishing of the 3D-XY area and the GL-area can be explained by the influence of the grain, also the different absolute values of the

  7. 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

  8. 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。

  9. A Case Study in Forensic Seismology: The 1998 Natural Gas Pipeline Explosion Near Carlsbad, New Mexico

    Science.gov (United States)

    Koper, K. D.; Wallace, T. C.; Aster, R. C.

    2002-12-01

    On August 19, 2000 two seismometer networks in southeastern New Mexico recorded signals from a natural gas pipeline explosion. The explosion killed 12 members of an extended family that had been camping on the banks of a nearby river. Analysis of the particle motion, arrival times, and durations of the seismic signals indicate that three impulsive events occurred with origin times of 11:26:18.8 +/- 1.9, 11:26:43.6 +/- 2.1, and 11:27:01.7 +/- 2.0 (GMT). Each event generated an Rg wave with group velocity of 1.7-2.0 km/s and an air-coupled Rayleigh wave with a group velocity of about 345 m/s. The air-coupled Rayleigh waves had especially large amplitudes because of a geometric waveguide created by an atmospheric temperature inversion at the time of the accident. The first event was due to the explosive blowout of the buried, high-pressure pipeline while the second event was due to the ignition of the vented natural gas. The nature of the third event is unclear, however it was likely created by a secondary ignition. There were also two extended seismic events that were coeval with the first two impulsive events. The first resulted from the pre-ignition venting of the gas and lasted for about 24~s, while the second resulted from the post-ignition roaring of the flames and lasted for about one hour. Many of the source constraints provided by the seismic data were not available from any other investigative technique and so were valuable to a diverse range of parties including the New Mexico State Police, law firms involved in litigation related to the accident, the National Transportation and Safety Board, and the general public. Especially important was the seismically derived time between the blowout and ignition. The 24.0~s lag indicates that the initial rending of the pipe did not cause the ignition and that a more likely source was the nearby campsite, and it also significantly affected the amount of punitive damages the families of the victims were due since the

  10. Computed tomography of orbital diseases in childhood

    International Nuclear Information System (INIS)

    , irregular, band-like density was seen along the posterior wall of the globe bilaterally. 6. Two cases of primary glaucoma showed large globe with a widened anterior chamber. 7. Among 6 cases of orbital fractures, 5 were blow-out fracture. The blow-out fractures showed fractures of the medial orbital wall or orbital floor with herniated intraorbital contents into the neighboring ethmoid or maxillary sinus

  11. 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

  12. 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

  13. Risk analysis on oil and gas leakage accident in offshore oil & gas field engineer%海上油气田工程油气泄漏事故风险分析

    Institute of Scientific and Technical Information of China (English)

    潘大新; 霍有利

    2009-01-01

    In the engineers of offshore oil & gas field, there exists a great deal of inflammable and explosive materials such as the crude oil and natural gas. There is always a leak risk of these materials which could lead to oil spill, fire and explosion accident. Based on a typical oil & gas engineer in Bohai Bay, The source, probability, aftermath and environment risk of oil and gas leak accident were studied. It showed that blowout, fire and explosion accident on the offshore platform and submarine pipeline leak are the main sources and the submarine pipeline leak probability is the greatest. The most serious aftermath of oil and gas leak is oil spill and the comparison and analysis of extent of oil spill in the construction and production period of the oil & gas field engineer were done. Based on these factors, the fault tree of the environment risk of blowout is most serious but the probability is lesser. The efficient measures abated the environment risk of two accidents were discussed for the fire and explosion caused on the offshore platform and submarine pipeline leak.%以渤海某工程项目为例研究海上油气田工程油气泄漏的事故及其风险.文章指出井喷、平台火灾事故和海底管道泄漏是海上油气田工程油气泄漏的主要事故源,并通过类比性分析得到三种事故的发生概率.油气泄漏的最严重后果是溢油事故,文章对各种事故的溢油规模进行分析,并根据井喷、平台火灾和海底管道泄漏三种事故发生的概率和规模对其环境影响进行评价.

  14. Effects of Pollution on Marine Organisms.

    Science.gov (United States)

    Mearns, Alan J; Reish, Donald J; Oshida, Philip S; Ginn, Thomas; Rempel-Hester, Mary Ann; Arthur, Courtney; Rutherford, Nicolle; Pryor, Rachel

    2015-10-01

    This review covers selected 2014 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 in part to the 2010 Deepwater Horizon oil blowout in the Gulf of Mexico and the 2011 Japanese tsunami. 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. PMID:26420104

  15. 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.

  16. Climatology of air quality of Long Valley Geothermal Resource Area

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, K.R.; Palmer, T.Y.

    1977-06-01

    The Long Valley Known Geothermal Resource Area is one of the more promising regions for development of a large-scale geothermal energy center. This report discusses the climatology and air quality of the area. Details are given on the temperatures, temperature inversions, and winds. Estimates are presented for the present air quality and future air quality during and following development of the resource area. Also discussed are project impact from added pollutants, noise, and precipitation augmentation. The major deleterious effects from development of the Long Valley Geothermal Resource Area appear to be due to increased dust loading during and following construction, and noise from production testing and potential well blowouts. Increased pollution from release of hydrogen sulfide and other pollutants associated with hot water geothermal wells seems to present no problems with regard to surrounding vegetation, potential contamination of Lake Crowley, and odor problems in nearby communities. Precipitation augmentation will probably increase the water level of Lake Crowley, at the expense of possible additional fogging and icing of nearby highways.

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

    International Nuclear Information System (INIS)

    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

  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. Overview: Hard Rock Penetration

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, J.C.

    1992-08-01

    The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

  20. Overview: Hard Rock Penetration

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, J.C.

    1992-01-01

    The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

  1. Overview - Hard Rock Penetration

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, James C.

    1992-03-24

    The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling Organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

  2. 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...

  3. Beaufort Region Environmental Assessment and Monitoring program (BREAM). Final report for 1992/1993

    International Nuclear Information System (INIS)

    The Beaufort Region Environmental Assessment and Monitoring (BREAM) program was established to identify environmental research and monitoring priorities related to future hydrocarbon development activities in the Beaufort Sea and Mackenzie Delta region. The activities occurring during the third year of BREAM focused on major oil spills. Three planning meetings were held: a Project Initiation Meeting and technical meetings of the Community-Based Concerns and Catastrophic Oil Spill Working Groups. The initiation meeting had goals that included identifying specific tasks to be completed by the two Working Groups, discussion of contents and scope of materials being prepared for an oil spill workshop, and determining project schedules. The Community-Based Concerns group focused its work on identifying ecological concerns related to oil spills and their cleanup, identifying community-based ecological issues and concerns, and incorporating local and traditional knowledge into the BREAM program. The group suggested changes to the wording of existing impact hypotheses and oil spill scenarios, and recommended changes in a list of valued ecosystem components. The oil spill group reviewed ecological concerns related to oil spills, and reviewed each oil spill scenario and impact hypothesis selected for an interdisciplinary workshop held in February 1993. The workshop evaluated four of the most important oil spill impact hypotheses (offshore platform blowout, river barge spill of diesel fuel, under-ice spill from a pipeline river crossing, and a pipeline spill affecting mammals). Further research and monitoring related to a number of impact hypotheses was recommended by workshop participants. 57 refs., 29 figs., 12 tabs

  4. 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.

  5. Coherent Thomson backscattering from laser-driven relativistic ultra-thin electron layers

    CERN Document Server

    Meyer-ter-Vehn, Jürgen

    2008-01-01

    The generation of laser-driven dense relativistic electron layers from ultra-thin foils and their use for coherent Thomson backscattering is discussed, applying analytic theory and one-dimensional particle-in-cell simulation. The blow-out regime is explored in which all foil electrons are separated from ions by direct laser action. The electrons follow the light wave close to its leading front. Single electron solutions are applied to initial acceleration, phase switching, and second-stage boosting. Coherently reflected light shows Doppler-shifted spectra, chirped over several octaves. The Doppler shift is found to be proportional to \\gamma_x^2=1/(1-\\beta_x^2), where \\beta_x is the electron velocity component in normal direction of the electron layer which is also the direction of the driving laser pulse. Due to transverse electron momentum p_y, the Doppler shift by 4*\\gamma_x^2=4*\\gamma^2/(1+(p_y/mc)^2) ~= 2*\\gamma is significantly smaller than full shift of 4*\\gamma^2. Methods to turn p_y -> 0 and to recove...

  6. 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.

  7. Reducing contaminated soil rehabilitation costs - review of portable XRF performance on Australian soils

    International Nuclear Information System (INIS)

    Mine owners and managers are often shocked by the financial costs involved in remediating metal contaminated soils, especially those associated with the closure of base metal mines. Lack of due consideration during planning, inappropriate operational controls for water and dust emissions, little monitoring data and new contaminated land legislation coupled with traditional owners seeking mining leases to be remediated to low (even background) levels are reasons for multi-million dollar cost blow-outs. At some base metal operations, emissions have travelled outside the mine lease impacting on neighbouring pastoral land and in some cases contaminating near-by communities. Traditional sampling and laboratory analysis costs have restricted the collection of data to adequately define the problem resulting in poor management of metal-contaminated soil. A portable analytical tool that provides on-site geochemistry could assist in identifying issues early, allowing for improved management practices and lower overall clean-up costs. This paper reviews independent evaluation studies for soil contaminated by heavy metal with XRF, using a new portable technology developed in the USA by the NITON Corporation

  8. 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. PMID:24035287

  9. Evaluation of the potential effects of major oil spills on Grand Banks commercial fish species as a result of impacts on eggs and larvae

    International Nuclear Information System (INIS)

    The Natural Resource Damage Assessment Model for Coastal and Marine Environments (NRDAM/CME) developed by the US Department of the Interior was applied to determine potential catch losses of two commercially important species in the event of an oil spill on the Grand Banks of Newfoundland. The model is made of a generalized physical fates model and a biological effects model; a fisheries component of the model estimates the ultimate impact on future adult fish populations and their harvesting. Inputs to the model include numbers of eggs and larvae, volume and nature of spill, chemical characteristics of the crude oil, and oceanographic and meteorological information specific to the spill location. To assess the sensitivity of the model predictions, different simulations each representing a specific combination of biological and physical conditions were carried out. In each case, the number of eggs and larvae killed and subsequent total lost catch as predicted by the model were directly proportional to the assumed egg and larval abundance. The impact on cod was three times that on plaice. In a worst-case situation involving a 90-d summer blowout at the maximum daily flow rate, the totals in lost catch of cod and plaice would be 21 and 7 tonnes respectively. These represent only 0.02% of the total annual Grand Banks catch for both species. 35 refs., 18 figs., 161 tabs

  10. MULTI-ELEMENT ABUNDANCE MEASUREMENTS FROM MEDIUM-RESOLUTION SPECTRA. IV. ALPHA ELEMENT DISTRIBUTIONS IN MILKY WAY SATELLITE GALAXIES

    International Nuclear Information System (INIS)

    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 comprise our data set. The average [α/Fe] ratios for all dSphs follow roughly the same path with increasing [Fe/H]. We do not observe the predicted knees in the [α/Fe] versus [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 dispersion, half-light radius, or Galactocentric distance.

  11. Role of direct laser acceleration in energy gained by electrons in a laser wakefield accelerator with ionization injection

    International Nuclear Information System (INIS)

    We have investigated the role that the transverse electric field of the laser plays in the acceleration of electrons in a laser wakefield accelerator 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 significant contribution to the maximum energy due to direct laser acceleration (DLA) of those electrons that undergo betatron motion in the plane of the polarization of the laser pulse. Eventually, DLA can be the dominant energy gain mechanism over acceleration due to the longitudinal field at the highest densities. (paper)

  12. 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.

  13. Large-eddy simulation of bubble-driven plume in stably stratified flow.

    Science.gov (United States)

    Yang, Di; Chen, Bicheng; Socolofsky, Scott; Chamecki, Marcelo; Meneveau, Charles

    2015-11-01

    The interaction between a bubble-driven plume and stratified water column plays a vital role in many environmental and engineering applications. As the bubbles are released from a localized source, they induce a positive buoyancy flux that generates an upward plume. As the plume rises, it entrains ambient water, and when the plume rises to a higher elevation where the stratification-induced negative buoyancy is sufficient, a considerable fraction of the entrained fluid detrains, or peels, to form a downward outer plume and a lateral intrusion layer. In the case of multiphase plumes, the intrusion layer may also trap weakly buoyant particles (e.g., oil droplets in the case of a subsea accidental blowout). In this study, the complex plume dynamics is studied using large-eddy simulation (LES), with the flow field simulated by hybrid pseudospectral/finite-difference scheme, and the bubble and dye concentration fields simulated by finite-volume scheme. The spatial and temporal characteristics of the buoyant plume are studied, with a focus on the effects of different bubble buoyancy levels. The LES data provide useful mean plume statistics for evaluating the accuracy of 1-D engineering models for entrainment and peeling fluxes. Based on the insights learned from the LES, a new continuous peeling model is developed and tested. Study supported by the Gulf of Mexico Research Initiative (GoMRI).

  14. Global reach: Red Deer oilfield expertise, not least in taming disasters, lures international clientele

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, A.

    2002-10-07

    The rise to international prominence of two Red Deer, Alberta, firms --Safety Boss and Red Flame -- by performing heroic feats in Kuwait's flaming oil fields, are chronicled. These two firms, along with several others in Red Deer, provide expertise in fire fighting that is sought after by petroleum companies in the farthest corners of the world. Red Deer companies can be found training Kazakhs, Russians, Kuwaitis, Iranians, and Turkmen in fighting oil well fires. Red Flame, for example developed a method called 'hot-tapping' while fighting blazing oil well fires in Kuwait, which they have since extended by developing hot-tapping equipment that would work on the highest pressure wells in the world. Last summer Red Flame personnel trained a Schlumberger crew in Kazakhstan working on custom-designed equipment that could perform at pressures of 5,000 psi. Red Flame also designed 'extended reach' hot-tapping in response to a request from Petro-Canada. Meanwhile, Safety Boss, the oldest and best known oil well fire fighting company in Canada, boasts of having extinguished 180 wells in their 1991 stint in Kuwait, while their closest competitor, Texas-based Wild Well, doused only 117. With improved safety policies and procedures the number of oil well blow-outs diminished dramatically in recent years, but there are always opportunities for the Red Deer expertise somewhere around the world.

  15. Analytical fuel property effects--small combustors

    Science.gov (United States)

    Sutton, R. D.; Troth, D. L.; Miles, G. A.

    1984-01-01

    The consequences of using broad-property fuels in both conventional and advanced state-of-the-art small gas turbine combustors are assessed. Eight combustor concepts were selected for initial screening, of these, four final combustor concepts were chosen for further detailed analysis. These included the dual orifice injector baseline combustor (a current production 250-C30 engine combustor) two baseline airblast injected modifications, short and piloted prechamber combustors, and an advanced airblast injected, variable geometry air staged combustor. Final predictions employed the use of the STAC-I computer code. This quasi 2-D model includes real fuel properties, effects of injector type on atomization, detailed droplet dynamics, and multistep chemical kinetics. In general, fuel property effects on various combustor concepts can be classified as chemical or physical in nature. Predictions indicate that fuel chemistry has a significant effect on flame radiation, liner wall temperature, and smoke emission. Fuel physical properties that govern atomization quality and evaporation rates are predicted to affect ignition and lean-blowout limits, combustion efficiency, unburned hydrocarbon, and carbon monoxide emissions.

  16. Analysis of 809 Facial Bone Fractures in a Pediatric and Adolescent Population

    Directory of Open Access Journals (Sweden)

    Sang Hun Kim

    2012-11-01

    Full Text Available Background Facial fractures are infrequent in children and adolescents and have differentclinical features from those in adults. The low incidence in children and adolescents reflectsthe flexibility and underdevelopment of their facial skeletons, as well as their more protectedenvironments. Only a few reports have reviewed such patients in Korea. The authors performeda retrospective study to analyze the characteristics of facial fractures in the Korean pediatricpopulation.Methods We conducted a retrospective review on a series of 741 patients, aged <18 years,with facial fractures who had been treated at our hospital between 2006 and 2010. Thefollowing parameters were evaluated: age, sex, cause, location and type of fractures, associatedinjuries, treatment and complications.Results A total of 741 consecutive patients met the inclusion criteria. The ratio of boys to girlswas 5.7:1. Facial fractures most commonly occurred in patients between 13 and 15 years ofage (36.3%. The most common causes of injury was violence. The nasal fracture was the mostcommon type of fracture (69% and the blowout fracture was the second most common (20%.Associated injuries occurred in 156 patients (21%.Conclusions The incidence of pediatric facial fractures caused by violence is high in Korea.Our results show that as age increases, etiological factors and fracture patterns gradually shifttowards those found in adults. This study provides an overview of facial fractures in these agegroups that helps illustrate the trends and characteristics of the fractures and may be helpfulin further evaluation and management.

  17. Do oil dispersants make spilled oil more toxic to fish?

    International Nuclear Information System (INIS)

    The Deepwater Horizon blowout in the Gulf of Mexico was the world's largest oil spill in terms of duration and volume spilled. Clean-up operations, which involved the continuous and wide-spread use of oil dispersant at the surface and at the seabed discharge point at 1500 metres depth, gave rise to public concern about dispersant toxicity. Reports from the United States Environmental Protection Agency (EPA) claimed little difference in acute toxicity to marine fish and invertebrate species among commonly available dispersants and between dispersed and non-dispersed Louisiana Sweet Crude. Technically, the toxicity of waterborne hydrocarbons does not vary with chemical dispersion. However, the EPA omitted any consideration of loading, and misled the public about the risks of dispersant use in oil clean-up. This study examined the chronic toxicity of dispersed oil to fish embryos. The study revealed that toxicity expressed as oil loading increases by a factor of 10 to 1000 times with dispersion, largely because 10 to 1000 times more oil enters the water column. Since the action of dispersant is on the exposure component of the risk equation, not on the potency of the toxic components of oil, then the risk of oil toxicity to fish increases an equivalent amount.

  18. δ(13)C and δ(15)N in deep-living fishes and shrimps after the Deepwater Horizon oil spill, Gulf of Mexico.

    Science.gov (United States)

    Quintana-Rizzo, Ester; Torres, Joseph J; Ross, Steve W; Romero, Isabel; Watson, Kathleen; Goddard, Ethan; Hollander, David

    2015-05-15

    The blowout of the Deepwater Horizon (DWH) drill-rig produced a surface oil layer, dispersed micro-droplets throughout the water column, and sub-surface plumes. We measured stable carbon and nitrogen isotopes in mesopelagic fishes and shrimps in the vicinity of DWH collected prior to, six weeks after, and one year after the oil spill (2007, 2010 and 2011). In 2010, the year of the oil spill, a small but significant depletion of δ(13)C was found in two mesopelagic fishes (Gonostoma elongatum and Chauliodus sloani) and one shrimp (Systellaspis debilis); a significant δ(15)N enrichment was identified in the same shrimp and in three fish species (G. elongatum, Ceratoscopelus warmingii, and Lepidophanes guentheri). The δ(15)N change did not suggest a change of trophic level, but did indicate a change in diet. The data suggest that carbon from the Deepwater Horizon oil spill was incorporated into the mesopelagic food web of the Gulf of Mexico. PMID:25778549

  19. Extraction and Characterization of Drilling Fluid from Castor Oil

    Directory of Open Access Journals (Sweden)

    Manase Auta

    2013-06-01

    Full Text Available Drilling fluid is an essential component in drilling operations. It is used to prevent blowouts by creating adequate hydrostatic pressure, lubricating the walls of a well and the drill string, flushing to the surface of cuttings, and keeping the drill bit clean and cool. Extraction, characterization and formation of drilling fluid from castor seed oil were investigated. The castor seeds used were obtained from a local market and the extraction of the oil was done mechanically. The extracted oil characteristics such as specific gravity, pH, acid value, iodine value, saponification value, refractive index and viscosity were within the standard range before before formulating it to drilling fluid by the addition of additives. The result of the formulation obtained showed that the formulated drilling fluid had an electrical stability of 222 V, High Pressure/High Temperature of 8.8, mass funnel viscosity at 30 and 50 oC were 26.5 and 25 s, respectively; chemical alkalinity was 0.3 and excess lime of 0.39 Ib/bbI. The findings in this research have shown that formulated drilling fluid from castor seed oil is safe as drilling fluid and has characteristics close to that of the standard drilling mud equivalent circulating density 99. The formulated drilling fluid can adequately serve as an alternative to the commercial products.

  20. 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.

  1. Petroleum : a social choice, but at what price?

    International Nuclear Information System (INIS)

    This article summarized an interview with the chief executive officer of Total, the fifth largest integrated oil company in the world. The interview addressed a range of issues, including oil price trends, industry costs and the company's investment strategy. Total has just invested $1.5 billion in Alberta's oil sands. BP's oil rig blowout and massive spill in the Gulf of Mexico in the summer of 2010 will likely generate interest in the world's second largest hydrocarbon reserves. The main challenge currently facing the CEO of Total is to remake the image of the industry at a time when politics and environmental concerns prevent oil companies from developing, or exploring for, hydrocarbon resources that are needed to meet growing energy demands. Issues of peak oil were also discussed. The CEO emphasized that new technologies continuously allow companies to explore deeper both underwater and underground, but these resources will cost more and be more expensive to operate, particularly if environmental impacts are to be minimized. Safety standards for exploration will likely be enhanced after the disaster in the Gulf of Mexico, despite the fact that very strict rules already exist in areas such as the North Sea and elsewhere. However, offshore oil will not be suddenly replaced by the oil sands, which generate their own environmental problems and have been the subject of attacks from environmentalists and Aboriginal communities. Carbon dioxide emissions, water use and water pollution have been singled out as the primary environmental concerns facing development of Alberta's oil sands. 3 figs.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  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. Simplified tornado depressurization design methods for nuclear power plants

    International Nuclear Information System (INIS)

    A simplified approach for the calculation of tornado depressurization effects on nuclear power plant structures and components is based on a generic computer depressurization analysis for an arbitrary single volume V connected to the atmosphere by an effective vent area A. For a given tornado depressurization transient, the maximum depressurization ΔP of the volume was found to depend on the parameter V/A. The relation between ΔP and V/A can be represented by a single monotonically increasing curve for each of the three design-basis tornadoes described in the U.S. Nuclear Regulatory Commission's Regulatory Guide 1.76. These curves can be applied to most multiple-volume nuclear power plant structures by considering each volume and its controlling vent area. Where several possible flow areas could be controlling, the maximum value of V/A can be used to estimate a conservative value for ΔP. This simplified approach was shown to yield reasonably conservative results when compared to detailed computer calculations of moderately complex geometries. Treatment of severely complicated geometries, heating and ventilation systems, and multiple blowout panel arrangements were found to be beyond the limitations of the simplified analysis

  8. 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.

  9. 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...

  10. Response time estimation for one oil spill originating from offshore facilities in Espirito Santo state (Brazil); Estimativa do tempo de resposta para um derrame de petroleo proveniente das instalacoes offshore do Espirito Santo

    Energy Technology Data Exchange (ETDEWEB)

    Barros, M.B.; Sarmento, R. [Espirito Santo Univ., Vitoria, ES (Brazil). Programa de Pos-graduacao em Engenharia Ambiental]. E-mail: borgesbarros@bol.com.br; robsar@npd.ufes.br

    2003-07-01

    Oil and gas exploration and production activities both offshore the coast of and inland the State of E. Santo promise to heat up the state's economy, thus bringing investments, creating jobs, and generating income. Inherent to this kind of activity there is the possibility of accidents occurring in spite of the complex safety systems installed on offshore facilities, such as equipment to prevent blowouts, bursting of pipes, structural defects in the platforms, as well as ship collisions. If the oil spill reaches the coastline, damages would be catastrophic. This would be so not only because this area is home to major ecological systems but also due to the fact that a significant part of the population lives along the coastline that is used for such activities as fishing, leisure, and port installations. Being thus this research has the objective of making available information that come to contribute for elaboration of a contingency plan for the activities of exploration offshore of the Espirito Santo State (Brazil), esteeming the time response for a possible accident happened in the capixaba coast, originating from the facilities offshore, considering the force of the wind as the only force acting on the oil spot. This estimate was accomplished through a model of trajectory of oil spill. (author)

  11. 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. PMID:17994916

  12. A Coronal Hole Jet Observed with Hinode and the Solar Dynamics Observatory

    Science.gov (United States)

    Young, Peter H.; Muglach, Karin

    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 × 10( exp 8) cu cm for the ejected plasma. Line-of-sight velocities reached up to 250 km/s. The density of the bright point was 7.6 × 10(exp 8) cu cm, and the peak of the bright point's emission measure occurred at 1.3 MK, with no plasma above 3 MK.

  13. EPDM and fluorocarbon seal materials: a comparison of performance for nuclear fuel transport flasks

    Energy Technology Data Exchange (ETDEWEB)

    Chivers, T.C. [Hosier Systems (International) Ltd. for British Nuclear Group, Berkeley, Gloucestershire (United Kingdom); George, A.F. [British Energy Generation Ltd, Gloucester, Gloucestershire (United Kingdom)

    2004-07-01

    The lid seals on the flasks used to transport spent fuel from U.K. AGR and Magnox Power Stations are fluorocarbon elastomer 'O' rings. Currently, only this material is qualified for the purpose and it was decided to investigate the possibility of qualifying other materials. One material that is already in use in similar applications is an Ethylene Propylene Diene Monomer (EPDM). The work presented in this paper compares the performance of the existing material with three candidate types of EPDM. The areas considered were: Extrusion and blow-out resistance when subjected to various steam pressures and temperatures at a range of flange separations, Permeability to water, caesium salt solution and hydrogen (as a typical 'benchmark' gas) Radiation resistance in warm (60 C) aqueous conditions It is concluded that the performance of the EPDM materials is good in respect of mechanical properties, radiation and water resistance. However, while permeation rates for gas and water can be higher than for fluorocarbon, this might be mitigated by assessing the actual radioactive burden in the permeate. In the case of dissolved salts, the test results indicate that this will be very low.

  14. δ13C and δ15N in deep-living fishes and shrimps after the Deepwater Horizon oil spill, Gulf of Mexico

    International Nuclear Information System (INIS)

    Highlights: • δ15N and δ13C were studied in mesopelagic species before and after the DWH oil spill. • A significant δ15N enrichment was identified in one shrimp and three fish species. • The nitrogen enrichment suggests a change in diet but not a change of trophic level. • A small but significant depletion of δ13C was found in two fishes and one shrimp. • The change in δ13C suggests incorporation of oil spill carbon into the food web. - Abstract: The blowout of the Deepwater Horizon (DWH) drill-rig produced a surface oil layer, dispersed micro-droplets throughout the water column, and sub-surface plumes. We measured stable carbon and nitrogen isotopes in mesopelagic fishes and shrimps in the vicinity of DWH collected prior to, six weeks after, and one year after the oil spill (2007, 2010 and 2011). In 2010, the year of the oil spill, a small but significant depletion of δ13C was found in two mesopelagic fishes (Gonostoma elongatum and Chauliodus sloani) and one shrimp (Systellaspis debilis); a significant δ15N enrichment was identified in the same shrimp and in three fish species (G. elongatum, Ceratoscopelus warmingii, and Lepidophanes guentheri). The δ15N change did not suggest a change of trophic level, but did indicate a change in diet. The data suggest that carbon from the Deepwater Horizon oil spill was incorporated into the mesopelagic food web of the Gulf of Mexico

  15. Transcriptional response of bathypelagic marine bacterioplankton to the Deepwater Horizon oil spill.

    Science.gov (United States)

    Rivers, Adam R; Sharma, Shalabh; Tringe, Susannah G; Martin, Jeffrey; Joye, Samantha B; Moran, Mary Ann

    2013-12-01

    The Deepwater Horizon blowout released a massive amount of oil and gas into the deep ocean between April and July 2010, stimulating microbial blooms of petroleum-degrading bacteria. To understand the metabolic response of marine microorganisms, we sequenced ≈ 66 million community transcripts that revealed the identity of metabolically active microbes and their roles in petroleum consumption. Reads were assigned to reference genes from ≈ 2700 bacterial and archaeal taxa, but most assignments (39%) were to just six genomes representing predominantly methane- and petroleum-degrading Gammaproteobacteria. Specific pathways for the degradation of alkanes, aromatic compounds and methane emerged from the metatranscriptomes, with some transcripts assigned to methane monooxygenases representing highly divergent homologs that may degrade either methane or short alkanes. The microbial community in the plume was less taxonomically and functionally diverse than the unexposed community below the plume; this was due primarily to decreased species evenness resulting from Gammaproteobacteria blooms. Surprisingly, a number of taxa (related to SAR11, Nitrosopumilus and Bacteroides, among others) contributed equal numbers of transcripts per liter in both the unexposed and plume samples, suggesting that some groups were unaffected by the petroleum inputs and blooms of degrader taxa, and may be important for re-establishing the pre-spill microbial community structure. PMID:23902988

  16. Mandibular reconstruction in the radiated patient: the role of osteocutaneous free tissue transfers

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, M.J.; Manktelow, R.T.; Zuker, R.M.; Rosen, I.B.

    1985-12-01

    This paper discusses our experience with the second metatarsal and iliac crest osteocutaneous transfers for mandibular reconstruction. The prime indication for this type of reconstruction was for anterior mandibular defects when the patient had been previously resected. Midbody to midbody defects were reconstructed with the metatarsal and larger defects with the iliac crest. In most cases, an osteotomy was done to create a mental angle. The evaluation of speech, oral continence, and swallowing revealed good results in all patients unless lip or tongue resection compromised function. Facial contour was excellent in metatarsal reconstructions. The iliac crest cutaneous flap provided a generous supply of skin for both intraoral reconstruction and external skin coverage but tended to be bulky, particularly when used in the submental area. Thirty three of 36 flaps survived completely. Flap losses were due to anastomosis thrombosis (1), pedicle compression (1), and pedicle destruction during exploration for suspected carotid blowout (1). Ninety three percent of bone junctions developed a solid bony union despite the mandible having had a full therapeutic dose of preoperative radiation. Despite wound infections in 8 patients, and intraoral dehiscence with bone exposure in 12 patients, all but one of these transfers went on to good bony union without infection in the bone graft.

  17. Mandibular reconstruction in the radiated patient: the role of osteocutaneous free tissue transfers

    International Nuclear Information System (INIS)

    This paper discusses our experience with the second metatarsal and iliac crest osteocutaneous transfers for mandibular reconstruction. The prime indication for this type of reconstruction was for anterior mandibular defects when the patient had been previously resected. Midbody to midbody defects were reconstructed with the metatarsal and larger defects with the iliac crest. In most cases, an osteotomy was done to create a mental angle. The evaluation of speech, oral continence, and swallowing revealed good results in all patients unless lip or tongue resection compromised function. Facial contour was excellent in metatarsal reconstructions. The iliac crest cutaneous flap provided a generous supply of skin for both intraoral reconstruction and external skin coverage but tended to be bulky, particularly when used in the submental area. Thirty three of 36 flaps survived completely. Flap losses were due to anastomosis thrombosis (1), pedicle compression (1), and pedicle destruction during exploration for suspected carotid blowout (1). Ninety three percent of bone junctions developed a solid bony union despite the mandible having had a full therapeutic dose of preoperative radiation. Despite wound infections in 8 patients, and intraoral dehiscence with bone exposure in 12 patients, all but one of these transfers went on to good bony union without infection in the bone graft

  18. 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.

  19. X-ray emission from the Wolf-Rayet bubble NGC 6888 - II. XMM-Newton EPIC observations

    Science.gov (United States)

    Toalá, J. A.; Guerrero, M. A.; Chu, Y.-H.; Arthur, S. J.; Tafoya, D.; Gruendl, R. A.

    2016-03-01

    We present deep XMM-Newton European Photon Imaging Camera observations of the Wolf-Rayet (WR) bubble NGC 6888 around the star WR 136. The complete X-ray mapping of the nebula confirms the distribution of the hot gas in three maxima spatially associated with the caps and north-west blowout hinted at by previous Chandra observations. The global X-ray emission is well described by a two-temperature optically thin plasma model (T1 = 1.4 × 106 K, T2 = 8.2 × 106 K) with a luminosity of LX = 7.8 × 1033 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 ne = 0.4 cm-3. The high-quality observations presented here reveal spectral variations within different regions in NGC 6888, 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 hot bubble is less efficient around the caps than in other nebular regions.

  20. 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.

  1. 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.

  2. 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.

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

    Science.gov (United States)

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

    2015-02-01

    We present an in-depth experimental-computational study of the parameters necessary to optimize a tunable, quasi-monoenergetic, efficient, low-background Compton backscattering (CBS) x-ray source that is based on the self-aligned combination of a laser-plasma accelerator (LPA) and a plasma mirror (PM). The main findings are (1) an LPA driven in the blowout regime by 30 TW, 30 fs laser pulses produce not only a high-quality, tunable, quasi-monoenergetic electron beam, but also a high-quality, relativistically intense (a0 ˜ 1) spent drive pulse that remains stable in profile and intensity over the LPA tuning range. (2) A thin plastic film near the gas jet exit retro-reflects the spent drive pulse efficiently into oncoming electrons to produce CBS x-rays without detectable bremsstrahlung background. Meanwhile, anomalous far-field divergence of the retro-reflected light demonstrates relativistic "denting" of the PM. Exploiting these optimized LPA and PM conditions, we demonstrate quasi-monoenergetic (50% FWHM energy spread), tunable (75-200 KeV) CBS x-rays, characteristics previously achieved only on more powerful laser systems by CBS of a split-off, counter-propagating pulse. Moreover, laser-to-x-ray photon conversion efficiency (˜6 × 10-12) exceeds that of any previous LPA-based quasi-monoenergetic Compton source. Particle-in-cell simulations agree well with the measurements.

  4. Coupled THCM Modeling of Gas Hydrate Bearing Sediments

    Science.gov (United States)

    Sanchez, M. J.; Gai, X., Sr.; Shastri, A.; Santamarina, J. C.

    2014-12-01

    Gas hydrates are crystalline clathrate compounds made of water and a low molecular gas, like methane. Gas hydrates are generally present in oil-producing areas and in permafrost regions. Methane hydrate deposits can lead to large-scale submarine slope failures, blowouts, platform foundation failures, and borehole instability. Gas hydrates constitute also an attractive source of energy as they are estimated to contain very large reserves of methane. Hydrate formation, dissociation and methane production from hydrate bearing sediments are coupled Thermo-Hydro-Mechanical (THM) processes that involve, amongst other, exothermic formation and endothermic dissociation of hydrate and ice phases, mixed fluid flow and large changes in fluid pressure. A comprehensive THM formulation is briefly presented here. Momentum balance, mass balance and energy balance equations take into consideration the interaction among all phases (i.e. solid, liquid, gas, hydrates and ice) and mechanical equilibrium. Constitutive equations describe the intrinsic THM behavior of the sediment. Simulation results conducted for hydrate bearing sediments subjected to boundary conditions highlight the complex interaction among THM processes in hydrate bearing sediments.

  5. 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.

  6. Environmental factors along the Northern Sea Route

    International Nuclear Information System (INIS)

    The Northern Sea Route runs ca 5,600 nautical miles across the top of Russia from Murmansk to Vladivostok, and includes half of the Arctic basin. An environmental impact assessment is needed for this route because of the potential for commercial shipping to disturb the vulnerable Arctic environment along the route. For example, Russian development of oil and gas resources in the area served by the route is expected to rise dramatically in the near future. Drilling in the route area offshore has already begun, and potential blowouts or tanker spills are of concern. A pilot study on the environment along this route was conducted in 1990/91, focusing on a study of the literature and communications with Russian scientists working on Arctic ecology. Existing data seem to be insufficient and generally only cover the westernmost and easternmost parts of the route. A five-year research plan is proposed to provide an inventory of Arctic species in the route area and levels of contaminants present, to assess the environmental sensitivity of the area, and analyze impacts that increased shipping might have on the environment. Protection measures will also be suggested. 1 fig

  7. Captains of industry

    International Nuclear Information System (INIS)

    The pivotal role of well-site supervisor in the successful drilling of an oil or gas well is described. In general, the well-site supervisor is the ultimate authority on the job-site; although often a contract employee, he represents the exploration and production companies, in contrast to the rig manger, commonly known as the tool push, who supervises the drilling staff. Well-site supervisors generally live at the drilling location, working for two-to-three week stretches with a week off to recuperate. They supervise anywhere from six to thirty-five people, depending on the activities conducted at the site ant any given time. They tend to be veterans of the industry, with vast experience on virtually all rungs of the oilfield employment ladder, well versed in all relevant machinery, people, the natural environment and the behaviour of underground geological forces. They have to be computer-literate; people skills also invariably rank high among the list of qualifications. Although the job is not taught in schools, well-site supervisors are certified in multiple skills, including well control, well service blow-out prevention, first aid, CPR, transportation of dangerous goods, workplace hazardous materials information systems, hydrogen sulfide rescue, surface casing minimum requirements, energy application and schedules development, and well abandonment. Major oil companies have their own well-site supervisors, but the industry-wide trend is outsourcing for expert help through engineering firms

  8. Non-linear theory of a cavitated plasma wake in a plasma channel for special applications and control

    Science.gov (United States)

    Thomas, Johannes; Kostyukov, Igor Yu.; Pronold, Jari; Golovanov, Anton; Pukhov, Alexander

    2016-05-01

    We introduce a complete semi-analytical model for a cavitated electron wake driven by an electron beam in a radially inhomogeneous plasma. The electron response to the driver, dynamics of electrons in a thin sheath surrounding the cavity, as well as accelerating and focusing fields inside the cavity are calculated in the quasistatic approximation. Our theory holds for arbitrary radial density profiles and reduces to known models in the limit of a homogeneous plasma. A free-propagating blow-out in an evacuated channel experiences longitudinal squeezing, qualitatively the same as observed in particle-in-cell simulations for the laser pulse-driven case [Pukhov et al., Phys. Rev. Lett. 113, 245003 (2014)]. Our model also permits qualitative interpretation of the earlier observed cancellation of the focusing gradient in the cavity [Pukhov et al., Phys. Rev. Lett. 113, 245003 (2014)]. In this work, we show the underlying mechanism that causes the radial fields in the vacuum part of a channel to become defocussing.

  9. A framework to quantify uncertainty in simulations of oil transport in the ocean

    Science.gov (United States)

    Gonçalves, Rafael C.; Iskandarani, Mohamed; Srinivasan, Ashwanth; Thacker, W. Carlisle; Chassignet, Eric; Knio, Omar M.

    2016-04-01

    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.

  10. Papers of the remediation technologies symposium 2005. CD-ROM ed.

    International Nuclear Information System (INIS)

    This conference was attended by over 500 delegates and provided an opportunity for industry, practitioners, researchers and regulators to discuss technical issues in environmental remediation research and recent innovations in soil and groundwater remediation. Sessions included presentations on in-situ, groundwater and surface water remediation. Issues concerning phytoremediation, natural attenuation, extraction and commercial redevelopment were examined. The aim of the conference was also to provide a forum for innovators in remediation to present new work. Topics included hydrocarbon and salt contamination; engineered soil cover for management of salt impacted sites; remediation and revegetation of tar sands composite tailings containing naphthenic acids; sorption of oil sands naphthenic acid mixtures; denitrification as a natural attenuation mechanism; sampling methodologies; variability assessments; stabilization treatment technologies; remediation of coal wastes; bioreactor landfills; well blowouts in Alberta; soil remediation in coarse gravelly soils; diesel-contaminated aquifers; gasoline spill remediation; soil vapour extraction systems; technological solutions for erosion control and water clarification; and cost-effective in-situ remediation strategies. Fifty-two technical presentations were given, of which 27 have been catalogued separately for inclusion in this database

  11. Papers of the remediation technologies symposium 2005. CD-ROM ed.

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    This conference was attended by over 500 delegates and provided an opportunity for industry, practitioners, researchers and regulators to discuss technical issues in environmental remediation research and recent innovations in soil and groundwater remediation. Sessions included presentations on in-situ, groundwater and surface water remediation. Issues concerning phytoremediation, natural attenuation, extraction and commercial redevelopment were examined. The aim of the conference was also to provide a forum for innovators in remediation to present new work. Topics included hydrocarbon and salt contamination; engineered soil cover for management of salt impacted sites; remediation and revegetation of tar sands composite tailings containing naphthenic acids; sorption of oil sands naphthenic acid mixtures; denitrification as a natural attenuation mechanism; sampling methodologies; variability assessments; stabilization treatment technologies; remediation of coal wastes; bioreactor landfills; well blowouts in Alberta; soil remediation in coarse gravelly soils; diesel-contaminated aquifers; gasoline spill remediation; soil vapour extraction systems; technological solutions for erosion control and water clarification; and cost-effective in-situ remediation strategies. Fifty-two technical presentations were given, of which 27 have been catalogued separately for inclusion in this database. tabs., figs.

  12. Debris disk size distributions: steady state collisional evolution with P-R drag and other loss processes

    CERN Document Server

    Wyatt, Mark C; Booth, Mark

    2011-01-01

    We present a new scheme for determining the shape of the size distribution, and its evolution, for collisional cascades of planetesimals undergoing destructive collisions and loss processes like Poynting-Robertson drag. The scheme treats the steady state portion of the cascade by equating mass loss and gain in each size bin; the smallest particles are expected to reach steady state on their collision timescale, while larger particles retain their primordial distribution. For collision-dominated disks, steady state means that mass loss rates in logarithmic size bins are independent of size. This prescription reproduces the expected two phase size distribution, with ripples above the blow-out size, and above the transition to gravity-dominated planetesimal strength. The scheme also reproduces the expected evolution of disk mass, and of dust mass, but is computationally much faster than evolving distributions forward in time. For low-mass disks, P-R drag causes a turnover at small sizes to a size distribution th...

  13. 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. PMID:26774768

  14. Hydrocarbon contamination affects deep-sea benthic oxygen uptake and microbial community composition

    Science.gov (United States)

    Main, C. E.; Ruhl, H. A.; Jones, D. O. B.; Yool, A.; Thornton, B.; Mayor, D. J.

    2015-06-01

    Accidental oil well blowouts have the potential to introduce large quantities of hydrocarbons into the deep sea and disperse toxic contaminants to midwater and seafloor areas over ocean-basin scales. Our ability to assess the environmental impacts of these events is currently impaired by our limited understanding of how resident communities are affected. This study examined how two treatment levels of a water accommodated fraction of crude oil affected the oxygen consumption rate of a natural, deep-sea benthic community. We also investigated the resident microbial community's response to hydrocarbon contamination through quantification of phospholipid fatty acids (PLFAs) and their stable carbon isotope (δ13C) values. Sediment community oxygen consumption rates increased significantly in response to increasing levels of contamination in the overlying water of oil-treated microcosms, and bacterial biomass decreased significantly in the presence of oil. Multivariate ordination of PLFA compositional (mol%) data showed that the structure of the microbial community changed in response to hydrocarbon contamination. However, treatment effects on the δ13C values of individual PLFAs were not statistically significant. Our data demonstrate that deep-sea benthic microbes respond to hydrocarbon exposure within 36 h.

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

    Science.gov (United States)

    Iskandarani, Mohamed; Wang, Shitao; Srinivasan, Ashwanth; Carlisle Thacker, W.; Winokur, Justin; Knio, Omar M.

    2016-04-01

    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.

  16. 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.

  17. Crude oil jets in crossflow: Effects of dispersant concentration on plume behavior

    Science.gov (United States)

    Murphy, David W.; Xue, Xinzhi; Sampath, Kaushik; Katz, Joseph

    2016-06-01

    This study investigates the effects of premixing oil with chemical dispersant at varying concentrations on the flow structure and droplet dynamics within a crude oil jet transitioning into a plume in a crossflow. It is motivated by the need to determine the fate of subsurface oil after a well blowout. The laboratory experiments consist of flow visualizations, in situ measurements of the time evolution of droplet-size distributions using holography, and particle image velocimetry to characterize dominant flow features. Increasing the dispersant concentration dramatically decreases the droplet sizes and increases their number, and accordingly, reduces the rise rates of droplets and the upper boundary of the plume. The flow within the plume consists primarily of a pair of counterrotating quasi-streamwise vortices (CVP) that characterize jets in crossflows. It also involves generation of vertical wake vortices that entrain small droplets under the plume. The evolution of plume boundaries is dominated by interactions of droplets with the CVP. The combined effects of vortex-induced velocity and significant quiescent rise velocity of large (˜5 mm) droplets closely agree with the rise rate of the upper boundary of the crude oil plume. Conversely, the much lower rise velocity of the smaller droplets in oil-dispersant mixtures results in plume boundaries rising at rates that are very similar to those of the CVP center. The size of droplets trapped by the CVP is predicted correctly using a trapping function, which is based on a balance of forces on a droplet located within a horizontal eddy.

  18. 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.

  19. The economics of exploiting gas hydrates

    International Nuclear Information System (INIS)

    We investigate the optimal exploitation of methane hydrates, a recent discovery of methane resources under the sea floor, mainly located along the continental margins. Combustion of methane (releasing CO2) and leakage through blow-outs (releasing CH4) contribute to the accumulation of greenhouse gases. A second externality arises since removing solid gas hydrates from the sea bottom destabilizes continental margins and thus increases the risk of marine earthquakes. We show that in such a model three regimes can occur: i) resource exploitation will be stopped in finite time, and some of the resource will stay in situ, ii) the resource will be used up completely in finite time, and iii) the resource will be exhausted in infinite time. We also show how to internalize the externalities by policy instruments. - Highlights: • We set up a model of optimal has hydrate exploitation • We incorporate to types of damages: contribution to global warming and geo-hazards • We characterize optimal exploitation paths and study decentralization with an exploitation tax. • Three regimes can occur: • i) exploitation in finite time and some of the stock remaining in situ, • ii) exploitation in finite time and the resource will be exhausted, • iii) exploitation and exhaustion in infinite time

  20. Oil Spill Contingency and Response (OSCAR) analysis in support of environmental impact assessment offshore Namibia

    International Nuclear Information System (INIS)

    The work reported here encompasses analyses of specific potential spill scenarios for oil exploration activity planned offshore of Namibia. The analyses are carried out with the SINTEF Oil Spill Contingency and Response (OSCAR) 3-dimensional model systems. A spill scenario using 150 m3 of marine diesel demonstrates the rapidity with which such a spill will dissipate naturally, even in light winds. Vertical and horizontal mixing bring subsurface hydrocarbon concentrations to background levels within a few days. A hypothetical 10 day blowout scenario releasing 11,000 bbl per day of light crude oil is investigated in terms of the potential for delivering oil to selected bird and marine mammal areas along the Namibian coast. Worst case scenarios are selected to investigate the potential mitigating effects of planned oil spill response actions. Mechanical recovery significantly reduces, and in some cases eliminates, potential environmental consequences of these worst case scenarios. Dispersant application from fixed wing aircraft further reduces the potential surface effects. The analysis supplies an objective basis for net environmental analysis of the planned response strategies. (Author)

  1. Safety relief valve performance for two-phase flow

    International Nuclear Information System (INIS)

    The performance of main steam safety relief valve has been evaluated with respect only to the steam. In the present study, two-phase flow and subcooled water blow-out tests with model valves were performed in order to evaluate the valve's characteristics and performance. From the test results, it was made clear that not only for the steam but also for the two-phase flow the measurement data were hardly affected by scaling and also that the reaction force of the fluid to the valve stem was hardly dependent upon the void fraction. Analytical study was performed using the two-phase flow model in the valve. The results of the analysis showed good agreement with the test data. It was shown from the test and analysis results that the reaction force of the two-phase flow and subcooled water to the valve stem was almost as much as that of the steam flow, and the integrity of the safety relief valve could be maintained. (author)

  2. 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.

  3. Preliminary studies to determine the shelf life of HEPA filters. Revision 1

    International Nuclear Information System (INIS)

    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

  4. History of the 30 years` operation of Otake and 20 years` operation of Hatchobaru power plants; Otake hatsudensho 30nen oyobi Hacchobaru hatsudensho 20 nen no ayumi

    Energy Technology Data Exchange (ETDEWEB)

    Haruguchi, K. [Kyushu Electric Power Co. Inc., Fukuoka (Japan)

    1998-03-15

    Falling on 30th year for the Otake power plant and 20th year for the Hatchobaru power plant since inauguration of their operation, this paper introduces the history of geothermal development to date in these areas. Geothermal development in the Otake area has begun when the Kyushu Power Distribution Co., Ltd., a predecessor of Kyushu Electric Power Co., Inc. made preliminary surveys on geothermal areas in Oita Prefecture in 1949. Four survey wells were drilled starting in 1953, which have succeeded in eruption, but the blowout was steam mixed with hot water rather than superheated steam. Technologies then available were not capable of utilizing the steam for power generation, and the development was suspended temporarily. Thereafter, the success in New Zealand of geothermal power generation of hot water separation type encouraged resumption of the development. It has resulted in inauguration of commercial operation as the Japan`s first commercial geothermal power plant in 1967. In the Hatchobaru area, geothermal survey has begun in 1963 by using mainly the geophysical exploration method. Excavations since about 1968 have successfully resulted in steam eruption, by which development plan for 50,000-kW output power generation was moved forward, and operation of the No. 1 unit began in 1977. 6 figs.

  5. Generating multi-GeV electron bunches using single stage laser wakefield acceleration in a 3D nonlinear regime

    CERN Document Server

    Lu, W; Joshi, C; Mori, W B; Silva, L O; Tsung, F S; Tzoufras, M; Vieira, J

    2006-01-01

    The extraordinary ability of space-charge waves in plasmas to accelerate charged particles at gradients that are orders of magnitude greater than in current accelerators has been well documented. We develop a phenomenological framework for Laser WakeField Acceleration (LWFA) in the 3D nonlinear regime, in which the plasma electrons are expelled by the radiation pressure of a short pulse laser, leading to nearly complete blowout. Our theory provides a recipe for designing a LWFA for given laser and plasma parameters and estimates the number and the energy of the accelerated electrons whether self-injected or externally injected. These formulas apply for self-guided as well as externally guided pulses (e.g. by plasma channels). We demonstrate our results by presenting a sample Particle-In-Cell (PIC) simulation of a 30f sec, 200T W laser interacting with a 0.75cm long plasma with density 1.5*10^18 cm^-3 to produce an ultra-short (10f s) mono-energetic bunch of self-injected electrons at 1.5 GeV with 0.3nC of cha...

  6. Nature of H-alpha selected galaxies at z>2. II. Clumpy galaxies and compact star-forming galaxies

    CERN Document Server

    Tadaki, Ken-ichi; Tanaka, Ichi; Hayashi, Masao; Koyama, Yusei; Shimakawa, Rhythm

    2013-01-01

    We present the morphological properties of 109 H\\alpha-selected galaxies at z>2 in SXDF-UDS-CANDELS field. With high-resolution optical/near-infrared images obtained by Hubble Space Telescope, we identify giant clumps within the H\\alpha emitters (HAEs). We find that at least 41% of our sample show clumpy structures in the underlying disks. The color gradient of clumps is commonly seen in the sense that the clumps near the galactic center tend to be redder than those in the outer regions. The mid-infrared detection in galaxies with red clumps and the spatial distribution of H\\alpha emission suggest that dusty star-formation activity is probably occurring in the nuclear red clumps. A gas supply to a bulge component through the clump migration is one of the most potent physical processes to produce such dusty star-forming clumps and form massive bulges in local early-type galaxies. They would become large quiescent galaxies at later times just by consumption or blowout of remaining gas. Also, while most of the H...

  7. Surface stability test plan for protective barriers

    International Nuclear Information System (INIS)

    Natural-material protective barriers for long-term isolation of buried waste have been identified as integral components of a plan to isolate a number of Hanford defense waste sites. Standards currently being developed for internal and external barrier performance will mandate a barrier surface layer that is resistant to the eolian erosion processes of wind erosion (deflation) and windborne particle deposition (formation of sand dunes). Thus, experiments are needed to measure rates of eolian erosion processes impacting those surfaces under different surface and climatological conditions. Data from these studies will provide information for use in the evaluation of selected surface layers as a means of providing stable cover over waste sites throughout the design life span of protective barriers. The multi-year test plan described in this plan is directed at understanding processes of wind erosion and windborne particle deposition, providing measurements of erosion rates for models, and suggesting construction materials and methods for reducing the effect of long-term eolian erosion on the barrier. Specifically, this plan describes possible methods to measure rates of eolian erosion, including field and laboratory procedure. Advantages and disadvantages of laboratory (wind tunnel) tests are discussed, and continued wind tunnel tests are recommended for wind erosion studies. A comparison between field and wind tunnel erosive forces is discussed. Plans for testing surfaces are described. Guidance is also presented for studying the processes controlling sand dune and blowout formation. 24 refs., 7 figs., 3 tabs

  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. 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).

  10. 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.

  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. 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.

  13. 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.

  14. Bubbles in galactic haloes

    CERN Document Server

    Shchekinov, Yu A; Schröer, A; Steinacker, A; Shchekinov, Yu. A.

    2001-01-01

    We briefly discuss a possible interconnection of vertical HI structures observed in the Milky Way Galaxy with large scale blow-outs caused by the explosions of multiple clustered SNe. We argue that the observed OB associations can produce only about 60 such events, or approximately one chimney per 3 kpc$^2$ within the solar circle. We also discuss the overall properties of HI shells in nearby face-on galaxies and the distribution of H$\\alpha$ and dust in edge-on galaxies. We argue that the presence of dust in galactic haloes may indicate that radiation pressure is the most probable mechanism capable of transporting dust to large heights above the galactic plane. In order to make this possible, the galactic magnetic field must have a strong vertical component. We mention that SNe explosions can initiate the Parker instability which in turn creates large scale magnetic loops with a strong vertical component. Recent observations of nearby edge-on galaxies favour this suggestion.

  15. 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.

  16. Real-time forecasting of ICME shock arrivals at L1 during the "April Fool’s Day" epoch: 28 March  21 April 2001

    Science.gov (United States)

    Sun, W.; Dryer, M.; Fry, C. D.; Deehr, C. S.; Smith, Z.; Akasofu, S.-I.; Kartalev, M. D.; Grigorov, K. G.

    2002-07-01

    The Sun was extremely active during the "April Fool’s Day" epoch of 2001. We chose this period between a solar flare on 28 March 2001 to a final shock arrival at Earth on 21 April 2001. The activity consisted of two presumed helmet-streamer blowouts, seven M-class flares, and nine X-class flares, the last of which was behind the west limb. We have been experimenting since February 1997 with real-time, end-to-end forecasting of interplanetary coronal mass ejection (ICME) shock arrival times. Since August 1998, these forecasts have been distributed in real-time by e-mail to a list of interested scientists and operational USAF and NOAA forecasters. They are made using three different solar wind models. We describe here the solar events observed during the April Fool’s 2001 epoch, along with the predicted and actual shock arrival times, and the ex post facto correction to the real-time coronal shock speed observations. It appears that the initial estimates of coronal shock speeds from Type II radio burst observations and coronal mass ejections were too high by as much as 30%. We conclude that a 3-dimensional coronal density model should be developed for application to observations of solar flares and their Type II radio burst observations.

  17. 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 ...

  18. 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...

  19. Features of a time domain simulation tool for rigid riser design

    Energy Technology Data Exchange (ETDEWEB)

    Morooka, Celso K.; Brandt, Dustin M. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Engenharia de Petroleo; Matt, Cyntia G.C.; Franciss, Ricardo [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

    2008-07-01

    This paper present a number of numerical implementations designed for the analysis of rigid riser's static and dynamic behavior that includes the effects of vortex induced vibrations (VIV) and marine hydrodynamic loads in time domain. Features include the ability to consider pipe with a free-span utilizing a soil/riser interaction model. An implementation of a numerical coupling scheme to couple the vertical riser and platform dynamics was developed to allow prediction of the sub sea Blow-Out Preventer (BOP) re-entry into a sub sea petroleum well when drilling different phases of deep and ultra-deep wells. The developments contains support for the consideration of the Self Standing Hybrid Riser (SSHR) configuration which has been shown to be a promising riser configuration in deep and ultra-deep waters. A graphical interface was also created to better grasp the results and aid in the modeling, processing and to help analyze the numerical simulations, contributing to enhance agility and quality of the riser design and analysis processes. (author)

  20. Design of a high-lift experiment in water including active flow control

    Science.gov (United States)

    Beutel, T.; Sattler, S.; El Sayed, Y.; Schwerter, M.; Zander, M.; Büttgenbach, S.; Leester-Schädel, M.; Radespiel, R.; Sinapius, M.; Wierach, P.

    2014-07-01

    This paper describes the structural design of an active flow-control experiment. The aim of the experiment is to investigate the increase in efficiency of an internally blown Coanda flap using unsteady blowing. The system uses tailor-made microelectromechanical (MEMS) pressure sensors to determine the state of the oncoming flow and an actuated lip to regulate the mass flow and velocity of a stream near a wall over the internally blown flap. Sensors and actuators are integrated into a highly loaded system that is extremely compact. The sensors are connected to a bus system that feeds the data into a real-time control system. The piezoelectric actuators using the d 33 effect at a comparable low voltage of 120 V are integrated into a lip that controls the blowout slot height. The system is designed for closed-loop control that efficiently avoids flow separation on the Coanda flap. The setup is designed for water-tunnel experiments in order to reduce the free-stream velocity and the system’s control frequency by a factor of 10 compared with that in air. This paper outlines the function and verification of the system’s main components and their development.

  1. Design of a high-lift experiment in water including active flow control

    International Nuclear Information System (INIS)

    This paper describes the structural design of an active flow-control experiment. The aim of the experiment is to investigate the increase in efficiency of an internally blown Coanda flap using unsteady blowing. The system uses tailor-made microelectromechanical (MEMS) pressure sensors to determine the state of the oncoming flow and an actuated lip to regulate the mass flow and velocity of a stream near a wall over the internally blown flap. Sensors and actuators are integrated into a highly loaded system that is extremely compact. The sensors are connected to a bus system that feeds the data into a real-time control system. The piezoelectric actuators using the d 33 effect at a comparable low voltage of 120 V are integrated into a lip that controls the blowout slot height. The system is designed for closed-loop control that efficiently avoids flow separation on the Coanda flap. The setup is designed for water-tunnel experiments in order to reduce the free-stream velocity and the system’s control frequency by a factor of 10 compared with that in air. This paper outlines the function and verification of the system’s main components and their development. (technical note)

  2. Firing blast furnace gas without support fuel in steel mill boilers

    International Nuclear Information System (INIS)

    Highlights: → BFG or BFG+COG was burned in steel mill boilers. → BFG was gradually added to replace COG in on-site experiments. → As COG was decreased, the flame remained stable. → Decreasing COG while keeping heat input constant reduced CO2 and NOx emissions. -- Abstract: 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 CO2 and NOx emissions.

  3. Real-time forecasting of ICME shock arrivals at L1 during the "April Fool’s Day" epoch: 28 March – 21 April 2001

    Directory of Open Access Journals (Sweden)

    W. Sun

    Full Text Available The Sun was extremely active during the "April Fool’s Day" epoch of 2001. We chose this period between a solar flare on 28 March 2001 to a final shock arrival at Earth on 21 April 2001. The activity consisted of two presumed helmet-streamer blowouts, seven M-class flares, and nine X-class flares, the last of which was behind the west limb. We have been experimenting since February 1997 with real-time, end-to-end forecasting of interplanetary coronal mass ejection (ICME shock arrival times. Since August 1998, these forecasts have been distributed in real-time by e-mail to a list of interested scientists and operational USAF and NOAA forecasters. They are made using three different solar wind models. We describe here the solar events observed during the April Fool’s 2001 epoch, along with the predicted and actual shock arrival times, and the ex post facto correction to the real-time coronal shock speed observations. It appears that the initial estimates of coronal shock speeds from Type II radio burst observations and coronal mass ejections were too high by as much as 30%. We conclude that a 3-dimensional coronal density model should be developed for application to observations of solar flares and their Type II radio burst observations.

    Key words. Interplanetary physics (flare and stream dynamics; interplanetary shocks – Magnetosheric physics (storms and substorms

  4. The dark side of development : First Nations worry the oilsands is irreparably harming the environment and community health

    Energy Technology Data Exchange (ETDEWEB)

    Stonehouse, D.

    2009-03-15

    This article reported on the concerns of the First Nations communities living in northern Alberta where oilsand development has impacted the environment. There are significant worries about water use and health concerns, with reported incidents of unusual cancers in their communities. Although no direct evidence blaming the oilsands industry has emerged, many in the community are convinced development is to blame. The All Parties Core Agreement was signed between the Athabasca Tribal Council (ATC) and the oilsands industry in an effort to address environmental challenges. Under the agreement, industry funded 5 environmental coordinators for each of the First Nations in the Athabasca region. The All Parties Core Agreement will build a community-based monitoring system and a cumulative effects assessment for the region. In 2008, the Metis Nation of northern Alberta discovered that many of the province's in situ oilsands developments lie over a vast groundwater system that flows into the Athabasca River. The group is concerned that blowouts at thermal operations could pollute the water system. Despite these concerns, the First Nations in the Athabasca region still tentatively support oilsands development, but only on the condition that their concerns are answered and that development progresses in a safe and sustainable manner. 1 fig.

  5. 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.

  6. Effect of age on the structural integrity of HEPA filters

    International Nuclear Information System (INIS)

    All of the controls on high-efficiency particulate air (HEPA) filters are based on rigid manufacturing standards with regard to filtration efficiency, temperature performance, pressure integrity, and strength. Third-party inspection and testing by the US Department of Energy increases the reliability of new HEPA filters, but only routine in-place testing is used to assure that an aging filter performs adequately. In 1980 the Lawrence Livermore National Laboratory initiated a small evaluation to determine if age has a significant effect on the structural integrity of HEPA filters. A series of used uncontaminated filters dating back to 1965 was obtained for these tests. Tensile strength tests on the old media indicated a decrease in strength. To provide additional measurement of the filters' overall strength, several of these aged filters were subjected to pressure pulses equivalent to the NRC Region I tornado pulses and shock wave over pressures. Data from these tests indicate a decrease in breaking pressure of from 25-50%. A large increase in complete filter pack blow-out during the simulated NRC Region I tornado tests was also observed. The preliminary results indicate the need for an administrative lifetime for HEPA filters used in critical nuclear facilities. Due to the unique conditions in each facility, different administrative lifetimes may be necessary

  7. Service alliances : new oilfield partnership techniques cut costs, put expertise to better use

    International Nuclear Information System (INIS)

    The co-operative relationship that is needed between service providers and oil companies was discussed. Oil exploration and oil production companies rely on members of the Petroleum Services Association of Canada (PSAC) for a wide range of specialties such as production testing, cementing and well stimulation, wireline data recording and perforating, drilling and completions, specialized trucking, pipe coating and inspection, blowout prevention, coring and tong services. For example, the Dowell division of Schlumberger Canada Ltd. has had long-term alliances with PanCanadian Petroleum Ltd., Chevron Canada Resources, Amoco Canada Petroleum Co., Suncor Energy Inc., Talisman Energy Inc., and Petro-Canada. Both the service providers and the oil companies work collaboratively to determine which processes should be used to achieve cost-cutting efficiency. The exchange of technological ideas is a definite advantage. In much the same manner, the Dominion Supply Co., (DOSCO) provides a wide variety of equipment and supplies to exploration and production firms, drilling contractors, and service contractors in the petroleum industry. 3 figs

  8. On the application of near accident data to risk analysis of major accidents

    International Nuclear Information System (INIS)

    Major accidents are low frequency high consequence events which are not well supported by conventional statistical methods due to data scarcity. In the absence or shortage of major accident direct data, the use of partially related data of near accidents – accident precursor data – has drawn much attention. In the present work, a methodology has been proposed based on hierarchical Bayesian analysis and accident precursor data to risk analysis of major accidents. While hierarchical Bayesian analysis facilitates incorporation of generic data into the analysis, the dependency and interaction between accident and near accident data can be encoded via a multinomial likelihood function. We applied the proposed methodology to risk analysis of offshore blowouts and demonstrated its outperformance compared to conventional approaches. - Highlights: • Probabilistic risk analysis is applied to model major accidents. • Two-stage Bayesian updating is used to generate informative distributions. • Accident precursor data are used to develop likelihood function. • A multinomial likelihood function is introduced to model dependencies among data

  9. Families near proposed sour gas wells wary company can protect them

    International Nuclear Information System (INIS)

    Public objections to the Compton Petroleum Corporation's intentions to add six new sour gas wells to an existing well it now operates near a residential area in the Calgary area, are discussed. Fifty-five families live within 15 km of the proposed wellsite; they are concerned about the safety of the plan, claiming that the company has not done enough to inform them about the potential hazards. Company officials assured residents that those living within the emergency zone (i.e. within four km of the wells) will be evacuated from the area before a blowout occurs. As far as residents outside the emergency zone are concerned, independent risk analysis experts testified that the risk to those residents is negligible. The company claims that Alberta law compels them to maximize the recovery of petroleum resources and by not drilling the proposed wells the company leaves itself open to charges for leaving some reserves in the ground. The Company also claims that by drilling the additional wells, it would be in a position to deplete the gas reserves faster, shut down the existing wells and return the land to the city much sooner than otherwise would be possible. Lawyers for the Coalition of Concerned Communities are challenging the Company's claim that the wells must be drilled so industry can make way for city expansion. 1 fig

  10. Implications of the presence of petroleum resources on the integrity of the WIPP

    International Nuclear Information System (INIS)

    The Waste Isolation Pilot Plant (WIPP) is a facility of the US Department of Energy (DOE), designed and constructed for the permanent disposal of transuranic (TRU) defense waste. The WIPP is surrounded by reserves of potash, crude oil, and natural gas. These are attractive targets for exploratory drilling which could disrupt the integrity of the transuranic waste repository. The performance assessment calculations published to date have identified future drilling for oil and gas reserves as an event that may disrupt the repository and may release radionuclides in excess of the standards. Therefore, the probability of inadvertent human intrusion into the repository by drilling and its impact on the integrity of the repository must be carefully assessed. This report evaluates: (1) the studies funded by the DOE to examine the crude oil potential in the immediate vicinity of the WIPP; (2) the use of an elicitation exercise to predict future drilling rates for use in the calculation of the repository performance; and (3) the observed limitations of institutional controls. This report identifies the following issues that remain to be resolved: (1) the limited performance of blowout preventers after drilling into high pressure zones immediately adjacent to the WIPP Site Boundary; (2) reported problems with waterflooding operations in southeastern New Mexico; (3) reported water level rises in several wells completed in the Rustler Formation, south of the WIPP Site, possibly due to oil and gas wells or leaking injection wells; and (4) reports of inadequate well abandonment practices on BLM leases and the continued absence of enforceable regulations

  11. Reirradiation of head and neck cancer focusing on hypofractionated stereotactic body radiation therapy

    International Nuclear Information System (INIS)

    Reirradiation is a feasible option for patients who do not otherwise have treatment options available. Depending on the location and extent of the tumor, reirradiation may be accomplished with external beam radiotherapy, brachytherapy, radiosurgery, or intensity modulated radiation therapy (IMRT). Although there has been limited experience with hypofractionated stereotactic radiotherapy (hSRT), it may have the potential for curative or palliative treatment due to its advanced precision technology, particularly for limited small lesion. On the other hand, severe late adverse reactions are anticipated with reirradiation than with initial radiation therapy. The risk of severe late complications has been reported to be 20- 40% and is related to prior radiotherapy dose, primary site, retreatment radiotherapy dose, treatment volume, and technique. Early researchers have observed lethal bleeding in such patients up to a rate of 14%. Recently, similar rate of 10-15% was observed for fatal bleeding with use of modern hSRT like in case of carotid blowout syndrome. To determine the feasibility and efficacy of reirradiation using modern technology, we reviewed the pertinent literature. The potentially lethal side effects should be kept in mind when reirradiation by hSRT is considered for treatment, and efforts should be made to minimize the risk in any future investigations

  12. Supra-bubble regime for laser acceleration of coldelectron beams in tenuous plasma

    Energy Technology Data Exchange (ETDEWEB)

    Geyko, V. I.; Dodin, I. Y.; Fisch, N. J.; Fraiman, G. M.

    2009-01-18

    Relativistic electrons can be accelerated by an ultraintense laser pulse in the "supra-bubble" regime, that is, in the blow-out regime ahead of the plasma bubble (as opposed to the conventional method, when particles remain inside the bubble). The acceleration is caused by the ponderomotive force of the pulse, via the so-called snow-plow mechanism. The maximum energy gain, Δγ ~ γg a, is attained when the particle Lorentz factor γ is initially about γg/a, where γg is the pulse group speed Lorentz factor, and a is the laser parameter, proportional to the laser field amplitude. The scheme operates at a ≤ γg, yielding Δγ of up to that via wakefield acceleration for the same plasma and laser parameters, Δγ ~ γ2g. The interaction length is shorter than that for the wake field mechanism but grows with the particle energy, hindering acceleration in multiple stages.

  13. Combustion and emissions characteristics of dual-channel double-vortex combustion for gas turbine engines

    International Nuclear Information System (INIS)

    Highlights: • A novel double-vortex combustor with a dual channel was designed. • The preheating effect of the evaporation tube is conducive to improving the combustion and emissions performance. • The combustion organization method of the combustor is reasonable. • The staged method significantly affects the performance of the combustor. - Abstract: A vortex combustor is a novel gas turbine combustor that uses staged combustion technology. Research examining the combustion organization method of the pilot combustion zone and the mainstream combustion zone is an important component of the design of the structure of a vortex combustor. In this paper, a new type of single-cavity vortex combustor fueled with aviation kerosene is presented. A double-vortex flow field structure and an evaporation tube for the fuel supply are used in the pilot zone. The flow-field structure of a double recirculation zone and a pneumatic atomization injector for the fuel supply are used in the mainstream combustion zone. The combustion experiment was performed under atmospheric pressure. The influence of the air-flow parameters, fuel parameters and staged method on the combustion performance and the characteristics of the pollutant emissions were studied in detail. Research indicates that the inlet temperature and the staged method primarily influence the ignition limit, lean blowout, combustion efficiency, temperature distribution of the outlet and pollutant emissions. The equivalence ratio primarily influences the temperature distribution of the wall and pollutant emissions. The inlet velocity influences the total pressure loss of the combustor

  14. Technology assessment of the use of dispersants on spills from drilling and production facilities in the Gulf of Mexico outer continental shelf

    International Nuclear Information System (INIS)

    The operational and environmental issues associated with dispersant use to clean up oil spills in the Gulf of Mexico (GOM) was assessed. The assessment included an examination of the dispersibility of oils plus the capabilities and limitations of spray platforms as well as the net environmental benefit of dispersing spills. Spill scenarios involving typical spill types, oil types, sizes, locations and environment were also analyzed. Gulf oils are typically light and apparently dispersible when they are fresh. The impact of weathering on dispersibility of GOM oils was assessed by analyzing oil spill scenarios. The time window (TW) for dispersion was estimated by oil fate modeling. Only 28 per cent of the oils produced in the GOM have been sufficiently characterized to allow for modeling. The majority of oils produced in the GOM have TW of a few days or longer, and are therefore amenable to chemical dispersion. The maximum theoretical dispersant delivery capacities of a range of spraying platforms were estimated using spreadsheet models. The environmental benefits of using dispersants were greatest in situations involving spills of manageable size, with persistent but dispersible oils and with a TW of more than 24 hours. This is because the oils would otherwise persist long enough to reach the shorelines where they would pose a threat. This analysis also suggested that the net environmental benefit is greater in a blowout spill than in a comparable batch spill. 23 refs., 5 tabs., 2 figs

  15. 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.

  16. Implications of the presence of petroleum resources on the integrity of the WIPP

    Energy Technology Data Exchange (ETDEWEB)

    Silva, M.K. [Environmental Evaluation Group, Albuquerque, NM (United States)]|[Environmental Evaluation Group, Carlsbad, NM (United States)

    1994-06-01

    The Waste Isolation Pilot Plant (WIPP) is a facility of the US Department of Energy (DOE), designed and constructed for the permanent disposal of transuranic (TRU) defense waste. The WIPP is surrounded by reserves of potash, crude oil, and natural gas. These are attractive targets for exploratory drilling which could disrupt the integrity of the transuranic waste repository. The performance assessment calculations published to date have identified future drilling for oil and gas reserves as an event that may disrupt the repository and may release radionuclides in excess of the standards. Therefore, the probability of inadvertent human intrusion into the repository by drilling and its impact on the integrity of the repository must be carefully assessed. This report evaluates: (1) the studies funded by the DOE to examine the crude oil potential in the immediate vicinity of the WIPP; (2) the use of an elicitation exercise to predict future drilling rates for use in the calculation of the repository performance; and (3) the observed limitations of institutional controls. This report identifies the following issues that remain to be resolved: (1) the limited performance of blowout preventers after drilling into high pressure zones immediately adjacent to the WIPP Site Boundary; (2) reported problems with waterflooding operations in southeastern New Mexico; (3) reported water level rises in several wells completed in the Rustler Formation, south of the WIPP Site, possibly due to oil and gas wells or leaking injection wells; and (4) reports of inadequate well abandonment practices on BLM leases and the continued absence of enforceable regulations.

  17. Captains of industry

    Energy Technology Data Exchange (ETDEWEB)

    Black, L.

    2000-05-01

    The pivotal role of well-site supervisor in the successful drilling of an oil or gas well is described. In general, the well-site supervisor is the ultimate authority on the job-site; although often a contract employee, he represents the exploration and production companies, in contrast to the rig manger, commonly known as the tool push, who supervises the drilling staff. Well-site supervisors generally live at the drilling location, working for two-to-three week stretches with a week off to recuperate. They supervise anywhere from six to thirty-five people, depending on the activities conducted at the site ant any given time. They tend to be veterans of the industry, with vast experience on virtually all rungs of the oilfield employment ladder, well versed in all relevant machinery, people, the natural environment and the behaviour of underground geological forces. They have to be computer-literate; people skills also invariably rank high among the list of qualifications. Although the job is not taught in schools, well-site supervisors are certified in multiple skills, including well control, well service blow-out prevention, first aid, CPR, transportation of dangerous goods, workplace hazardous materials information systems, hydrogen sulfide rescue, surface casing minimum requirements, energy application and schedules development, and well abandonment. Major oil companies have their own well-site supervisors, but the industry-wide trend is outsourcing for expert help through engineering firms.

  18. High-Resolution Numerical Model for Predicting the Transport and Dispersal of Oil Spilled in the Black Sea

    Directory of Open Access Journals (Sweden)

    Konstantin A. Korotenko

    2010-01-01

    Full Text Available The coupled DieCAST-SSBOM (Shirshov-Stony Brook Oil spill transport Model circulation-oil spill transport model is used to predict the transport and dispersal of contaminants resulting from representative hypothetical oil spills in the Black Sea. With climatological forcing, the DieCAST model realistically simulates many of the dominant mesoscale features of seasonally-varying large scale circulation and meso-scale features of the circulation including the Rim Current, anticyclonic coastal eddies, headland eddy shedding and vertical stratification. The oil spill model ingests DieCAST surface currents and employs a Lagrangian tracking algorithm to predict the motion of a large number of seeded particles, the sum of which (~1 million form the oil plume. Basic processes affecting the transport of oil and its fate (advection, sinking, evaporation, etc. are included as parameters. Various scenarios of hypothetical blowouts of oil in different regions of the sea are simulated and discussed as to their structure, transport and likelihood of coastal contamination. The ultimate objective is to develop an operational oil slick model forced with synoptic winds and air-sea interaction.

  19. Methane rising from the Deep: Hydrates, Bubbles, Oil Spills, and Global Warming

    Science.gov (United States)

    Leifer, I.; Rehder, G. J.; Solomon, E. A.; Kastner, M.; Asper, V. L.; Joye, S. B.

    2011-12-01

    Elevated methane concentrations in near-surface waters and the atmosphere have been reported for seepage from depths of nearly 1 km at the Gulf of Mexico hydrate observatory (MC118), suggesting that for some methane sources, deepsea methane is not trapped and can contribute to atmospheric greenhouse gas budgets. Ebullition is key with important sensitivity to the formation of hydrate skins and oil coatings, high-pressure solubility, bubble size and bubble plume processes. Bubble ROV tracking studies showed survival to near thermocline depths. Studies with a numerical bubble propagation model demonstrated that consideration of structure I hydrate skins transported most methane only to mid-water column depths. Instead, consideration of structure II hydrates, which are stable to far shallower depths and appropriate for natural gas mixtures, allows bubbles to survive to far shallower depths. Moreover, model predictions of vertical methane and alkane profiles and bubble size evolution were in better agreement with observations after consideration of structure II hydrate properties as well as an improved implementation of plume properties, such as currents. These results demonstrate the importance of correctly incorporating bubble hydrate processes in efforts to predict the impact of deepsea seepage as well as to understand the fate of bubble-transported oil and methane from deepsea pipeline leaks and well blowouts. Application to the DWH spill demonstrated the importance of deepsea processes to the fate of spilled subsurface oil. Because several of these parameters vary temporally (bubble flux, currents, temperature), sensitivity studies indicate the importance of real-time monitoring data.

  20. 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.

  1. On the diffuse X-ray emission from the Wolf-Rayet Bubble NGC 2359

    CERN Document Server

    Toalá, J A; Chu, Y -H; Gruendl, R A

    2014-01-01

    A recent XMM-Newton observation (Zhekov 2014) has revealed diffuse X-ray emission inside the nebula NGC 2359 around the Wolf-Rayet star WR 7. Taking advantage of an improved point-source rejection and background subtraction, and a detailed comparison of optical and X-ray morphology, we have reanalyzed these X-ray observations. Our analysis reveals diffuse X-ray emission from a blowout and the presence of emission at energies from 1.0 to 2.0 keV. The X-ray emission from NGC 2359 can be described by an optically-thin plasma emission model, but contrary to previous analysis, we find that the chemical abundances of this plasma are similar to those of the optical nebula, with no magnesium enhancement, and that two components at temperatures T_1=2x10^6 K and T_2=5.7x10^7 K are required. The estimated X-ray luminosity in the 0.3 - 2.0 keV energy range is L_X=2x10^33 erg s^-1. The averaged rms electron density of the X-ray-emitting gas (n_e \\lesssim 0.6 cm^-3) reinforces the idea of mixing of material from the outer ...

  2. Reirradiation of head and neck cancer focusing on hypofractionated stereotactic body radiation therapy

    Directory of Open Access Journals (Sweden)

    Ogita Mikio

    2011-08-01

    Full Text Available Abstract Reirradiation is a feasible option for patients who do not otherwise have treatment options available. Depending on the location and extent of the tumor, reirradiation may be accomplished with external beam radiotherapy, brachytherapy, radiosurgery, or intensity modulated radiation therapy (IMRT. Although there has been limited experience with hypofractionated stereotactic radiotherapy (hSRT, it may have the potential for curative or palliative treatment due to its advanced precision technology, particularly for limited small lesion. On the other hand, severe late adverse reactions are anticipated with reirradiation than with initial radiation therapy. The risk of severe late complications has been reported to be 20- 40% and is related to prior radiotherapy dose, primary site, retreatment radiotherapy dose, treatment volume, and technique. Early researchers have observed lethal bleeding in such patients up to a rate of 14%. Recently, similar rate of 10-15% was observed for fatal bleeding with use of modern hSRT like in case of carotid blowout syndrome. To determine the feasibility and efficacy of reirradiation using modern technology, we reviewed the pertinent literature. The potentially lethal side effects should be kept in mind when reirradiation by hSRT is considered for treatment, and efforts should be made to minimize the risk in any future investigations.

  3. Experimental and Computational Study of Trapped Vortex Combustor Sector Rig with High-Speed Diffuser Flow

    Directory of Open Access Journals (Sweden)

    R. C. Hendricks

    2001-01-01

    Full Text Available The Trapped Vortex Combustor (TVC potentially offers numerous operational advantages over current production gas turbine engine combustors. These include lower weight, lower pollutant emissions, effective flame stabilization, high combustion efficiency, excellent high altitude relight capability, and operation in the lean burn or RQL modes of combustion. The present work describes the operational principles of the TVC, and extends diffuser velocities toward choked flow and provides system performance data. Performance data include EINOx results for various fuel-air ratios and combustor residence times, combustion efficiency as a function of combustor residence time, and combustor lean blow-out (LBO performance. Computational fluid dynamics (CFD simulations using liquid spray droplet evaporation and combustion modeling are performed and related to flow structures observed in photographs of the combustor. The CFD results are used to understand the aerodynamics and combustion features under different fueling conditions. Performance data acquired to date are favorable compared to conventional gas turbine combustors. Further testing over a wider range of fuel-air ratios, fuel flow splits, and pressure ratios is in progress to explore the TVC performance. In addition, alternate configurations for the upstream pressure feed, including bi-pass diffusion schemes, as well as variations on the fuel injection patterns, are currently in test and evaluation phases.

  4. 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.

  5. 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

  6. Natural versus Urban dunes along the Emilia-Romagna coast, Northern Adriatic (Italy)

    Science.gov (United States)

    Corbau, Corinne; Simeoni, Umberto

    2014-05-01

    Beach-dune interaction models can be precious tools for land managers and policymakers. However, if the models are inaccurate, land use policies may be designed based on false pretences or assumptions leading to poor land management, long-term erosion and sustainability issues, and increased difficulties in maintaining the dynamic coastal systems. From the literature, it appears that even the most reliable beach-dunes interactions models are not applicable to all coastal systems (Short and Hesp, 1982; Psuty, 1988; Sherman and Bauer, 1993). The study aims to identify the morphological evolution of the Emilia-Romagna coastal dunes according to its natural and "human" characteristics and to classify groups of dunes with similar evolutionary patterns. The coastal area consists essentially of 130 km of low sandy coast, interrupted by vast lagoon areas, harbor jetties and numerous hard coastal defense structures that were built during the first half of the 20th century to protect the Emilia-Romagna coast against erosion. Today about 57% of the littoral is protected by hard defenses, which have modified the morphodynamic characteristics of the beach without inverting the negative coastal evolution's trend. From recent aerial photographs (2011), 62 coastal dunes have been identified and mapped. Furthermore, the dune analysis shows a variability of the "physical characteristics" of coastal-dune systems along the Emilia-Romagna coast. The dune height varies from 1 to 7 meters, the width of the beach and of the active dunes range respectively from 10 to 150 m and from 10 to 65 m. Three main factors may explain the variability of the "physical characteristics": 1- Firstly the frontal dunes may be of different states according to the classification of Hesp (2002) since they correspond to incipient foredunes, well-developed foredunes, blowouts, residual foredunes as well as reactivated relict foredunes, 2- This could also be related to a different orientation of the coastline

  7. Understanding the build-up of SMBH and Galaxies

    Science.gov (United States)

    Carrera, Francisco; Georgakakis, Antonis; Ueda, Yoshihiro; Akylas, Thanassis; Lanzuisi, Giorgio; Castello, N.

    2015-09-01

    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 ionised material 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

  8. 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

  9. 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.

  10. 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.

  11. Drafting force majeure clauses in natural gas purchase/sale contracts -- the practicalities

    International Nuclear Information System (INIS)

    The place of 'force majeure' provisions, in gas purchase/sale contracts is discussed. This issue, not normally considered to be significant in gas purchase/sale contracts, became a matter of intense interest in the aftermath of the Atcor Ltd v. Continental Energy Marketing case when the trial court, as well as the Alberta Court of Appeals, strongly criticized the wording of the force majeure clause in the contract as containing a 'choice of words that assured litigation'. Force majeure, simply stated, refers to acts of God, (lightning, earthquakes, storms, floods, etc) and acts of war. It is inserted in contracts to limit the liability of parties to the contract in the event of inability to perform due to any of the above acts of God, or acts of war. In this particular case, the force majeure cause included, in addition to the above, a long list of other causes such as strikes, lockouts or other industrial disturbances, insurrections, riots, epidemics, landslides, fires, washouts, explosions of or accidents to plant, machinery or lines of pipe, well blowouts, and pipeline repairs and reconditioning. The trial court found the drafting of the clause archaic, circumventing clarity, and drearily lengthy. In view of the court's decision it is clear that more thought has to go into drafting force majeure decisions in the future. Accordingly, this paper attempts to discuss practical issues of drafting force majeure clauses that clearly reflect the parties' intentions and expectations so that costly litigations might be avoided, or if litigation is unavoidable, to at least have the outcome of such litigation be more predictable. The focus of the discussion is on legal interpretation issues, forms of gas contract force majeure provisions- events and consequences, and standardization of force majeure provisions. It is recommended that the drafter of such clauses should always keep in mind the potential impact that the strict construction and commercial reasonability concepts

  12. Transient Pressure Surges Due to Pipe Movement in an Oil Well Surpressions transitoires dues au mouvement des colonnes de tubes dans les puits.

    Directory of Open Access Journals (Sweden)

    Lubinski A.

    2006-11-01

    Full Text Available A pressure surge which could cause lost circulation, results from running a stand of drill pipe or a joint of casing into a hole. Similarly, a negative pressure surge, which could cause a blowout, results from pulling pipe from a hole. In past investigations, pressure surges were calculated on the basis of steady state flow. It is shown in this paper that this led to erroneous results. In thls investigation, pressure surges are calculated on the basis of transient wave propagation phenomena. A computer program was developed to that effect. Results are presented in :the first part of the paper, and the mathematics in the second. La descente d'une longueur de tiges ou d'un tube de casing dans le trou provoque une surpression pouvant entraîner des pertes de circulation. De même, la remontée des tiges provoque une surpression négative pouvant entraîner une éruption. Au cours des précédentes recherches, les surpressions étaient calculées pour des débits en régime permanent. Il est montré dans cet étude que les résultats ainsi obtenus ne sont pas exacts. Dans cette recherche, les calculs des surpressions sont basés sur le phénomène de propagation transitoire des ondes. Un programme de calcul sur ordinateur a été développé à cet effet. Les résultats sont présentés dans la première partie de cet article et les calculs font l'objet de la deuxième partie.

  13. 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.

  14. 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)

  15. Endangered species and cultural resources program, Naval Petroleum Reserves in California: Annual report FY95

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-01

    In FY95, EG and G Energy Measurements, Inc. (EG and G/EM) continued to support efforts to protect endangered species and cultural resources at the Naval Petroleum Reserves in California (NPRC). These efforts are conducted to ensure NPRC compliance with regulations regarding the protection of listed species and cultural resources on Federal properties. Population monitoring activities are conducted annually for San Joaquin kit foxes, giant kangaroo rats, blunt-nosed leopard lizards, and Hoover`s wooly-star. To mitigate impacts of oil field activities on listed species, 674 preactivity surveys covering approximately 211 hectares (521 acres) were conducted in FY95. EG and G/EM also assisted with mitigating effects from third-party projects, primarily by conducting biological and cultural resource consultations with regulatory agencies. EG and G/EM has conducted an applied habitat reclamation program at NPRC since 1985. In FY95, an evaluation of revegetation rates on reclaimed and non-reclaimed disturbed lands was completed, and the results will be used to direct future habitat reclamation efforts at NPRC. In FY95, reclamation success was monitored on 50 sites reclaimed in 1985. An investigation of factors influencing the distribution and abundance of kit foxes at NPRC was initiated in FY94. Factors being examined include habitat disturbance, topography, grazing, coyote abundance, lagomorph abundance, and shrub density. This investigation continued in FY95 and a manuscript on this topic will be completed in FY96. Also, Eg and G/EM completed collection of field data to evaluate the effects of a well blow-out on plant and animal populations. A final report will be prepared in FY96. Finally, EG and G/EM completed a life table analysis on San Joaquin kit foxes at NPRC.

  16. 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.

  17. Potential of ambient noise techniques to monitor reservoir dynamics at the St. Gallen geothermal site

    Science.gov (United States)

    Obermann, A.; Larose, E. F.; Wiemer, S.

    2014-12-01

    In the last decade two large geothermal energy projects were launched in Switzerland (Basel 2006, St Gallen 2013). Both of them were stopped after the occurrence of strongly felt earthquakes (Ml3.4 and 3.5, respectively). This illustrates that one of the key challenges for the use of deep geothermal energy remains to control the risk of inducing felt and potentially hazardous seismic events during the development and operation of an underground heat exchangers. Current monitoring techniques of induced seismicity, e.g. traffic light systems, attempt to forecast seismic hazard during and after stimulation based on observed seismicity and hydraulic data. A limitation of these techniques is their focus on seismic processes. We demonstrate the potential of ambient seismic noise correlation techniques to monitor aseismic reservoir dynamics related to the 2013 geothermal project in St. Gallen. In St. Gallen, reservoir characterization tests lead to an unexpected leakage of methane gas into the well. Well-head pressure rose rapidly and operators decided to prevent a possible well blow-out with counter-pressure. The result was an immediate increase of induced seismicity with a maximum event of Ml3.5. While the reservoir characterization was not accompanied by any significant induced seismicity that could have given an indication for the ongoing processes in the reservoir, ambient noise cross-correlations reveal a significant aseismic perturbation in the system that can be clearly linked to the stimulation tests. These additional constraints may help to better understand reservoir dynamics. We also discuss the future role of noise correlation based techniques for monitoring/mitigation purposes.

  18. Oil Pollution in the Marine Environment: A 35 Year Perspective of Communicating Broadly

    Science.gov (United States)

    Farrington, J. W.; Tripp, B. W.

    2006-12-01

    Large accidental oil spills such as the tanker Torrey Canyon off the United Kingdom in 1967 and the Santa Barbara Oil Well Blowout of 1969, and attendant publicity, demonstrated that oil spills could be messy, have adverse effects on birds and other wildlife by oiling, and capture the public attention. However, careful scientific study of oil spills using modern biological sciences methods and modern geochemical analyses were needed to overcome the "out of sight, out of mind" conclusion that all was well when visible oil slicks on the water's surface disappeared. Documenting the long lasting persistence of chemicals from spilled oils and attendant biological effects began with a few dedicated scientists who not only published their findings in the scientific literature, but also made them known in testimony before Congress, in interviews with the press and publishing in magazines designed to communicate science to the public. They served as examples for our own efforts, and those of colleagues, to communicate the magnitude of the chronic input of petroleum compounds to the oceans as a result of the every day use of fossil fuels and how this input was quantitatively much larger than inputs from accidental spills and resulted in contamination of coastal areas near urban harbors and at offshore dumpsites. Over a period of the past thirty years mainly during 1971-2000, we used a combination of participation in review and advisory panels and committees, testimony before Congress, letters to government officials, public lectures, articles in the lay press, print and electronic media interviews, and museum exhibits to communicate the message from our scientific papers in ways that could be understood by the general public and acted on by their elected and appointed officials. Lessons learned from these efforts will be summarized

  19. An approach for estimating toxic releases of H2S-containing natural gas

    International Nuclear Information System (INIS)

    Highlights: • Behavior of H2S-containing natural gas exhibits appearance of neutral gas by CFD. • The poisoning hazards of H2S by gas pipeline releases are successfully estimated. • An assessment method for available safe egress time is proposed. -- Abstract: 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

  20. 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.

  1. 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. PMID:24091526

  2. 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). PMID:26397475

  3. 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

  4. Geochemical and isotopic time series of oil deposited in Barataria Bay and on Grand Isle, Louisiana, after the Deepwater Horizon Oil Spill

    Science.gov (United States)

    Finkelstein, D. B.; Schimmelmann, A.; Rosenheim, B. E.

    2012-12-01

    We present time-series of bulk hydrocarbon geochemical and compound specific isotopic data of oiled and tarry sediment deposits from Grand Isle and Barataria Bay, Louisiana. Samples were taken between 46 days and 694 days after the Macondo well blowout, and analyzed for bulk hydrocarbon stable carbon and hydrogen isotope ratios, n-alkane and other organic molecular characteristics, ramped pyrolysis stable carbon ratios and radiocarbon content, and compound specific isotope analysis. Bulk and compound specific stable hydrogen isotopes point to slight 2H-enrichment attributable to water washing during transport to Grand Isle and Barataria Bay, followed by more subtle changes after deposition that depended in part on the wave energy available locally. Characterization of the n-alkane distributions through time identified subtle shifts in the dominant n-alkanes from water washing and terrestrial degradation. The loss of high molecular weight n-alkanes and an increase in the unresolved complex mixture after day 337 is consistent with a shift from slight to moderate biodegradation. More significant variations were observed in elemental H:C ratios, whereas bulk stable carbon isotope values showed small increases through time. Ramped pyrolysis analyses illustrated relatively volatile and reactive petroleum-derived components were present during the first year following the spill, but they ultimately became less apparent during later sampling. Isotope results from different ramped pyrolysis components are discussed. Compound specific isotope analysis indicate that a combination of variables (e.g., tidal water washing and biodegradation) may impact degradation during the first 200 days. This period was followed by a mixing of Macondo and non-Macondo hydrocarbons in the environment. In sum, our analyses show the complementary roles of abiotic and biotic factors in degradation of the Deepwater Horizon oil that was deposited in different environments of coastal Louisiana.

  5. 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).

  6. 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.

  7. 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 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"); 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

  8. Optical control of electron trapping: Generation of comb-like electron beams for tunable, pulsed, multi-color radiation sources

    Science.gov (United States)

    Kalmykov, Serge

    2014-10-01

    All-optical control over the electron phase space in laser-plasma accelerators enables production of ``designer'' electron beams that can be optimized for specific applications. GeV-scale acceleration with sub-100 TW (rather than PW) laser pulses, at repetition rates orders-of-magnitude higher than permitted by existing PW facilities, in a few-mm (rather than cm) length plasmas, requires maintaining an accelerating gradient as high as 10 GV/cm. This, in turn, dictates acceleration in the blowout regime in a dense plasma (~1019 cm-3). These highly dispersive plasmas rapidly transform the drive pulse into a relativistic optical shock, causing the plasma wake bucket (electron density bubble) to constantly expand, trapping background electrons, greatly degrading beam quality. We show that these effects can be overcome using a high-bandwidth driver (over 1/2 the carrier frequency) with a negative frequency chirp. Temporally advancing higher frequencies (thus compensating for the plasma-induced nonlinear frequency red-shift) and propagating the pulse in a plasma channel (to suppress diffraction of its leading edge) delays pulse self-steepening through electron dephasing and extends the dephasing length. As a result, continuous injection is suppressed and electron energy is boosted to the GeV level. In addition, periodic self-injection in the channel produces a sequence of femtosecond-length, quasi-monoenergetic bunches. The number of these spectral components, their charge, energy, and energy separation can be controlled by varying the channel radius and length, whereas accumulation of the noise (viz. continuously injected charge) is prevented by the negative chirp of the driver. This level of control is hard to achieve with conventional accelerator techniques. It is demonstrated that these clean, polychromatic, comb-like beams can drive high-brightness, tunable, multi-color gamma-ray sources. Work is supported by the US DOE Grant DE-SC0008382 and NSF Grant PHY-1104683.

  9. Physical processes at work in sub-30 fs, PW laser pulse-driven plasma accelerators: Towards GeV electron acceleration experiments at CILEX facility

    International Nuclear Information System (INIS)

    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

  10. And now for something completely different: condensation induced water hammer and steam assisted gravity drainage in the Athabasca Oil Sands

    International Nuclear Information System (INIS)

    Most people will have been exposed to some aspect of the debate about the Athabasca Oil Sands in North-Eastern Alberta and the significant role that the oil sands are expected to play in supplying conventional fossil fuels. Part of the bitumen is recovered from mines and part is recovered from in situ projects utilizing the Steam Assisted Gravity Drainage Process (SAGD). SAGD utilizes a considerable amount of steam, that is injected into geological formations. Hot water, bitumen and some vapour are recovered from the production wells. With significant steam generation, transmission and injection, there is the very real possibility of condensation induced water hammers. There have been a number of catastrophic failures to date. Two major failures will be highlighted: MEG Energy had a steam distribution line fail at the Christina Lake project. Large parts of the pipe, weighing some 2500 kg, were thrown some 800 meters into the bush during the failure; and, Total had a steam release (blowout) at their Joslyn property due to a loss of caprock containment. A number of causes have been postulated. While it is agreed that there was sufficient downhole pressure to hydraulically fracture the formation, questions have been raised about the contribution that condensation induced water hammer made. The situations that have occurred will be outlined, along with some preliminary thermal hydraulic work. The intent of the paper is to provide interesting background information on the in situ oil sands industry. More importantly, to show some interesting and broader applications of thermalhydraulics developed in the nuclear industry. The expertise developed may have potential markets, with some adaptation, to the oil sands industry. Finally, there has been some discussion about using nuclear power for steam generation in the oil sands. (author)

  11. The role of natural gas hydrates in global changes

    International Nuclear Information System (INIS)

    The main features of gas hydrates which produce global changes are: structure and composition of hydrates, heat of the phase transition and of accumulation and decomposition (about 420 kJ kg-1), the change of the water specific volume (26-32%) under its transition to the hydrate state, and the electric impulse formation between the two phases during the phase transitions of systems. One volume of water contains 70-200 volumes of gas in hydrate state. Gas pressure in the crystal lattice of hydrate is hundreds, even thousands MPa. The hydrate formation zone is associated with frigid areas of Earth sedimentary rocks; on the land, near the polar regions, in the sea, at any latitude at depths >200-500 m. Methane hydrate resources make up about 104 Gt, 99% of them under the sea. The explored resources are 500 Gt. Hydrate methane is, undoubtedly, the energy potential of mankind for the next century, but the rates of the free methane outflow into the atmosphere and their influence on the global climate, ecology, geography, etc. need to be taken into account. The current amount of methane in the atmosphere is about 4.8 Gt. Thus, the average Earth surface temperature is increased by 1.3 K. The annual increase of methane in the atmosphere is 1%. Natural gas hydrates, their spreading and features may cause blowouts of free methane to the atmosphere, much greater than the current biochemical and technogenic sources. Methane may flow from the top and from the bottom of the layer as well under changing thermodynamic conditions, such as decreasing pressure, increase of the geothermal gradient, neotectonic shifts, changing of the hydrate deposits, electric potential. The free methane provides for an increase of CO2, H2O, O3 concentration. The heating effect of methane can be equal to or exceed that of CO2

  12. 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

  13. Assessment of the spatial and temporal variability of bulk hydrocarbon respiration following the Deepwater Horizon oil spill.

    Science.gov (United States)

    Du, Mengran; Kessler, John D

    2012-10-01

    Following the Deepwater Horizon blowout, the respiration of hydrocarbons dissolved and trapped in the deep and intermediate waters of the Gulf of Mexico imparted a significant reduction in dissolved oxygen (DO) concentration and stimulated a bloom of bacteria biomass. The investigation of 1316 DO profiles measured from 11 May until 20 September 2010 revealed the spatial and temporal variability of bulk hydrocarbon respiration in these deep and intermediate plumes. These analyses suggest that while there were occasional reversals in direction, the general movement of these plumes was toward the southwest and that the cumulative loss of DO peaked from 14 August through 18 September at a value of 18.9 ± 3.8 Gmol. These oxygen-based analyses were extended to determine a first-order estimate of the total release of hydrocarbon mass to the environment that must be less than or equal to the true release based on the inherent assumptions; these analyses estimate a total environmental release of 0.47 ± 0.09 Tg of hydrocarbons. These analyses estimate a total mass of 0.18 ± 0.05 Tg hydrocarbons in the plume layers fully respired to CO(2), 0.10 ± 0.08 Tg hydrocarbons incorporated into biomass, and the biomass/hydrocarbon conversion efficiency of 0.36 ± 0.11 mg biomass/mg hydrocarbon. These analyses also suggest that methane was the dominant hydrocarbon controlling the bulk respiration rates, that the rates peaked around 11 July, and that the addition of dispersants to the wellhead effectively accelerated hydrocarbon respiration. PMID:22913707

  14. THE M81 GROUP DWARF IRREGULAR GALAXY DDO 165. I. HIGH-VELOCITY NEUTRAL GAS IN A POST-STARBURST SYSTEM

    International Nuclear Information System (INIS)

    We present new multi-configuration Very Large Array H I spectral line observations of the M81 group dwarf irregular post-starburst galaxy DDO 165. The H I morphology is complex, with multiple column density peaks surrounding a large region of very low H I surface density that is offset from the center of the stellar distribution. The bulk of the neutral gas is associated with the southern section of the galaxy; a secondary peak in the north contains ∼15% of the total H I mass. These components appear to be kinematically distinct, suggesting that either tidal processes or large-scale blowout have recently shaped the interstellar medium (ISM) of DDO 165. Using spatially resolved position-velocity maps, we find multiple localized high-velocity gas features. Cross-correlating with radius-velocity analyses, we identify eight shell/hole structures in the ISM with a range of sizes (∼400-900 pc) and expansion velocities (∼7-11 km s-1). These structures are compared with narrow- and broadband imaging from the Kitt Peak National Observatory and the Hubble Space Telescope (HST). Using the latter data, recent works have shown that DDO 165's previous 'burst' phase was extended temporally (∼>1 Gyr). We thus interpret the high-velocity gas features, H I holes, and kinematically distinct components of the galaxy in the context of the immediate effects of 'feedback' from recent star formation (SF). In addition to creating H I holes and shells, extended SF events are capable of creating localized high-velocity motion of the surrounding interstellar material. A companion paper connects the energetics from the H I and HST data.

  15. 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.

  16. 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.

  17. Similarity of ionized gas nebulae around unobscured and obscured quasars

    Science.gov (United States)

    Liu, Guilin; Zakamska, Nadia L.; Greene, Jenny E.

    2014-08-01

    Quasar feedback is suspected to play a key role in the evolution of massive galaxies, by removing or reheating gas in quasar host galaxies and thus limiting the amount of star formation. In this paper, we continue our investigation of quasar-driven winds on galaxy-wide scales. We conduct Gemini Integral Field Unit spectroscopy of a sample of luminous unobscured (type 1) quasars, to determine the morphology and kinematics of ionized gas around these objects, predominantly via observations of the [O III] λ5007 Å emission line. We find that ionized gas nebulae extend out to ˜13 kpc from the quasar, that they are smooth and round, and that their kinematics are inconsistent with gas in dynamical equilibrium with the host galaxy. The observed morphological and kinematic properties are strikingly similar to those of ionized gas around obscured (type 2) quasars with matched [O III] luminosity, with marginal evidence that nebulae around unobscured quasars are slightly more compact. Therefore, in samples of obscured and unobscured quasars carefully matched in [O III] luminosity, we find support for the standard geometry-based unification model of active galactic nuclei, in that the intrinsic properties of the quasars, of their hosts and of their ionized gas appear to be very similar. Given the apparent ubiquity of extended ionized regions, we are forced to conclude that either the quasar is at least partially illuminating pre-existing gas or that both samples of quasars are seen during advanced stages of quasar feedback. In the latter case, we may be biased by our [O III]-based selection against quasars in the early `blow-out' phase, for example due to dust obscuration.

  18. 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.

  19. 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.

  20. KECK/NIRC2 IMAGING OF THE WARPED, ASYMMETRIC DEBRIS DISK AROUND HD 32297

    International Nuclear Information System (INIS)

    We present Keck/NIRC2 Ks -band high-contrast coronagraphic imaging of the luminous debris disk around the nearby, young A star HD 32297 resolved at a projected separation of r = 0.''3-2.''5 (≈35-280 AU). The disk is highly warped to the north and exhibits a complex, 'wavy' surface brightness (SB) profile interior to r ≈ 110 AU, where the peaks/plateaus in the profiles are shifted between the NE and SW disk lobes. The SW side of the disk is 50%-100% brighter at r = 35-80 AU, and the location of its peak brightness roughly coincides with the disk's millimeter (mm) emission peak. Spectral energy distribution modeling suggests that HD 32297 has at least two dust populations that may originate from two separate belts, likely at different locations, possibly at distances coinciding with the SB peaks. A disk model for a single dust belt including a phase function with two components and a 5-10 AU pericenter offset explains the disk's warped structure and reproduces some of the SB profile's shape (e.g., the overall 'wavy' profile, the SB peak/plateau shifts) but more poorly reproduces the disk's brightness asymmetry and the profile at wider separations (r > 110 AU). Although there may be alternate explanations, agreement between the SW disk brightness peak and disk's peak mm emission is consistent with an overdensity of very small, sub-blowout-sized dust and large, 0.1-1 mm sized grains at ≈45 AU tracing the same parent population of planetesimals. New near-IR and submillimeter observations may be able to clarify whether even more complex grain scattering properties or dynamical sculpting by an unseen planet are required to explain HD 32297's disk structure.

  1. Ice effects on a barge-based oil spill response system in the Alaskan Beaufort Sea

    Energy Technology Data Exchange (ETDEWEB)

    Bronson, M.; Thompson, E. [BP Exploration Alaska Inc., Anchorage, AK (United States); McAdams, F.; McHale, J. [Alaska Clean Seas, Prudhoe Bay, AK (United States)

    2002-07-01

    In 1999 Alaska Clean Seas assembled a marine oils spill response task force at Prudhoe Bay in preparation for potential oil well blowout in the Beaufort Sea, especially in pack ice conditions. The effects of pack ice on response efforts was measured in timed trials in the nearshore Beaufort Sea. A spill containment and recovery barge-based system reached its oil spill response operating limit in the thick ice of spring and in the thin ice of autumn at concentrations below 1/10. When the boom sweep encountered ice with 1/10 or more coverage, the ice became concentrated in the boom apex and isolated the skimmers. If thick ice pieces were longer than 7 meters, they lifted the boom, and rolled under it. Smaller pieces were able to either move through the apex, or accumulate in the boom. Ice breakers were able to manage the ice in their path by reducing thick drift ice concentrations from 3/10 and 5/10 down to less than 1/10. Barge-based booms were also able to direct ice pieces down the boom length to the boom apex. A pair of steel grates along the hull of the barge protected the floating LORI side brush skimmers from ice damage. A 5 per cent down time was experienced in a continuous 12 hour test in pack ice due to interference from drift ice. The total average down time was 12 per cent of the test period. Barges could move through the ice at break-up in July. By fall freeze-up, slush ice would accumulate, but it did not obstruct the weir skimmer pumps and hoses, not did it interfere with the skimmer's brushes. 8 refs., 5 tabs., 4 figs.

  2. 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

  3. LITIGATING CROSS-BORDER ENVIRONMENTAL DISPUTE IN INDONESIAN CIVIL COURT: THE MONTARA CASE

    Directory of Open Access Journals (Sweden)

    Iman Prihandono

    2015-04-01

    Full Text Available In August 2009, a wellhead blowout of took place at an offshore drilling facility named the Montara platform, on the north coast of Australia. This incident releases crude oil into the sea and continued until November 2009. The Montara platform owned by PTTEP Australasia Pty. Ltd., a company incorporated under the laws of Australia, and is a subsidiary of PTT Exploration and Production Public Company Limited, a Thailand based, state-owned oil company. Based on samples taken by the East Nusa Tenggara Municipality in the waters along the coast Kolbano, Desa Tuafanu, District Kualin, South Central Timor, it was found that the sea water has been polluted with crude oil. There was an indication that the crude oil is identical to those of at the Montara well head platform. This incident has been detrimental to at least 9.000 fishermen and seaweed farmers along the coast of West Timor Sea, with total losses estimated at USD2.4 billion. This article examines the possibility of a lawsuit brought by the affected communities to the Indonesian civil court. This article finds that that filing a lawsuit against PTTEP AA, the operator of the Montara Platform, may be possible. Article 100 RV of the Indonesian civil procedure provide an opportunity to sue foreign entity when contractual relationship exist. This article seeks to map the possible parties involved in the dispute should the victims decide to bring this case to Indonesian civil court. It aims at assisting the victims in preparing their case and obtaining the best possible outcome for remedy.

  4. Sensors, motes, and smart dust : WirelessHART sensors are finding application in gas plants, well rigs and soon may be embraced by entire cities

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, G.

    2009-05-15

    The WirelessHART (Highway Addressable Remote Transducer) is wireless communication system designed to address the needs of the process industry. The sensor system can be used in applications that were previously not practical or possible, such as in drilling rigs and gas plants. The wireless aspect is an important new innovation that delivers key economic benefits. For some temperature measurements in industrial plants, it is not always feasible to run wires all the way up the stack. The wireless solution consists of wireless gateways and field devices that receive and condition data from sensors that measure temperatures, pressures, flow rates, vibration, and other process parameters. The same devices also relay the measurement data to the gateway. Up to 100 devices can be linked wirelessly to a gateway, which passes on the process information to the control system of the plant, drilling rig, or other industrial facility. Multiple networks can be bridged using Wi-Fi. Once deployed, the technology optimizes itself. The system is also useful for determining temperatures and pressures on the mud tanks at drilling rigs and blowout preventers. The system is being used in highly automated and multi-process plants like refineries and upgraders where numerous sensors are needed. Savings on the wireless installations allow a company to afford the installation of more sensors in places they previously could not cost-effectively deploy wired sensors, thereby resulting in improved productivity, safety, and reduced plant downtimes. Talisman Energy's Teepee Creek sour gas plant near Grande Prairie Alberta uses the WirelessHART network to measure temperatures, pressure, differential pressure, tank levels, and valve positions. 4 figs.

  5. New perspectives on the transition between discrete fracture, fragmentation, and pulverization during brittle failure of rocks

    Science.gov (United States)

    Griffith, W. A.; Ghaffari, H.; Barber, T. J.; Borjas, C.

    2015-12-01

    The motions of Earth's tectonic plates are typically measured in millimeters to tens of centimeters per year, seemingly confirming the generally-held view that tectonic processes are slow, and have been throughout Earth's history. In line with this perspective, the vast majority of laboratory rock mechanics research focused on failure in the brittle regime has been limited to experiments utilizing slow loading rates. On the other hand, many natural processes that pose significant risk for humans (e.g., earthquakes and extraterrestrial impacts), as well as risks associated with human activities (blow-outs, explosions, mining and mine failures, projectile penetration), occur at rates that are hundreds to thousands of times faster than those typically simulated in the laboratory. Little experimental data exists to confirm or calibrate theoretical models explaining the connection between these dramatic events and the pulverized rocks found in fault zones, impacts, or explosions; however the experimental data that does exist is thought-provoking: At the earth's surface, the process of brittle fracture passes through a critical transition in rocks at high strain rates (101-103s-1) between regimes of discrete fracture and distributed fragmentation, accompanied by a dramatic increase in strength. Previous experimental works on this topic have focused on key thresholds (e.g., peak stress, peak strain, average strain rate) that define this transition, but more recent work suggests that this transition is more fundamentally dependent on characteristics (e.g., shape) of the loading pulse and related microcrack dynamics, perhaps explaining why for different lithologies different thresholds more effectively define the pulverization transition. In this presentation we summarize some of our work focused on this transition, including the evolution of individual defects at the microscopic, microsecond scale and the energy budget associated with the brittle fragmentation process as a

  6. Avoiding pollution in scientific ocean drilling

    International Nuclear Information System (INIS)

    Scientific ocean drilling has been carried out in the world's oceans since the nineteen sixties. From 1968-83 the Deep Sea Drilling Project (DSDP), managed by the Scripps Institution of Oceanography in California under a contract with the US National Science Foundation, employed the drilling vessel Glomar Challenger for this purpose. In January 1985 the Ocean Drilling Program (GDP), operated by Texas A and M University, began operations with the drillship JOIDES Resolution which continue to this day. The principal funding agency remains the US National Science Foundation, but since its inception GDP has been an international program and currently receives financial support from 21 countries. The ODP operates globally and, as with DSDP before it, drills without a riser or blowout preventer in a wide range of geological environments. Water depths at GDP drill sites have ranged from 38 m to 5969 m, but are typically within the range 1000-5000 m. Depths of penetration at GDP drill sites, while generally less than 1000 m, have ranged up to 2111 m below the sea floor. The drilling fluid is seawater, although occasional slugs of mud are circulated to clean or condition the hole. Thus drilling is carried out without well control, i.e. without the ability to control pressures within the well. Because of the absence of well control, it is vital to ensure that the drillship does not drill into an accumulation of oil or gas. Drilling into a charged reservoir and causing oil or gas to escape into the marine environment is recognised as the main pollution hazard in scientific ocean drilling

  7. The construction of the Jiangyin imported food supermarket feasibility research report%建设江阴进口食品超市可行性调研报告

    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.

  8. LATERAL OFFSET OF THE CORONAL MASS EJECTIONS FROM THE X-FLARE OF 2006 DECEMBER 13 AND ITS TWO PRECURSOR ERUPTIONS

    International Nuclear Information System (INIS)

    Two GOES sub-C-class precursor eruptions occurred within ∼10 hr prior to and from the same active region as the 2006 December 13 X4.3-class flare. Each eruption generated a coronal mass ejection (CME) with center laterally far offset (∼> 45°) from the co-produced bright flare. Explaining such CME-to-flare lateral offsets in terms of the standard model for solar eruptions has been controversial. Using Hinode/X-Ray Telescope (XRT) and EUV Imaging Spectrometer (EIS) data, and Solar and Heliospheric Observatory (SOHO)/Large Angle and Spectrometric Coronagraph (LASCO) and Michelson Doppler Imager (MDI) data, we find or infer the following. (1) The first precursor was a 'magnetic-arch-blowout' event, where an initial standard-model eruption of the active region's core field blew out a lobe on one side of the active region's field. (2) The second precursor began similarly, but the core-field eruption stalled in the side-lobe field, with the side-lobe field erupting ∼1 hr later to make the CME either by finally being blown out or by destabilizing and undergoing a standard-model eruption. (3) The third eruption, the X-flare event, blew out side lobes on both sides of the active region and clearly displayed characteristics of the standard model. (4) The two precursors were offset due in part to the CME originating from a side-lobe coronal arcade that was offset from the active region's core. The main eruption (and to some extent probably the precursor eruptions) was offset primarily because it pushed against the field of the large sunspot as it escaped outward. (5) All three CMEs were plausibly produced by a suitable version of the standard model.

  9. 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

  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. Spitzer Infrared Spectrograph Spectroscopy of the 10 Myr Old EF Cha Debris Disk: Evidence for Phyllosilicate-rich Dust in the Terrestrial Zone

    Science.gov (United States)

    Currie, Thayne; Lisse, Carey M.; Sicilia-Aguilar, Aurora; Rieke, George H.; Su, Kate Y. L.

    2011-06-01

    We describe Spitzer Infrared Spectrograph spectroscopic observations of the ~10 Myr old star, EF Cha. Compositional modeling of the spectra from 5 μm to 35 μm confirms that it is surrounded by a luminous debris disk with LD /L sstarf ~ 10-3, containing dust with temperatures between 225 K and 430 K, characteristic of the terrestrial zone. The EF Cha spectrum shows evidence for many solid-state features, unlike most cold, low-luminosity debris disks but like some other 10-20 Myr old luminous, warm debris disks (e.g., HD 113766A). The EF Cha debris disk is unusually rich in a species or combination of species whose emissivities resemble that of finely powdered, laboratory-measured phyllosilicate species (talc, saponite, and smectite), which are likely produced by aqueous alteration of primordial anhydrous rocky materials. The dust and, by inference, the parent bodies of the debris also contain abundant amorphous silicates and metal sulfides, and possibly water ice. The dust's total olivine to the pyroxene ratio of ~2 also provides evidence of aqueous alteration. The large mass volume of grains with sizes comparable to or below the radiation blow-out limit implies that planetesimals may be colliding at a rate high enough to yield the emitting dust but not so high as to devolatize the planetesimals via impact processing. Because phyllosilicates are produced by the interactions between anhydrous rock and warm, reactive water, EF Cha's disk is a likely signpost for water delivery to the terrestrial zone of a young planetary system.

  12. 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.

  13. 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.

  14. New technological developments in oil well fire fighting equipment and methods

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, B.; Matthews, R.T.

    1995-12-31

    Since Drake`s first oil well in 1859, well fires have been frequent and disastrous. Hardly a year has passed in over a century without a well fire somewhere in the world. In the 1920`s the classic method of fire fighting using explosives to starve the fire of oxygen was developed and it has been used extensively ever since. While explosives are still one of the most frequently used methods today, several other methods are used to supplement it where special conditions exist. Tunneling at an angle from a safe distance is used in some cases, especially where the fire is too hot for a close approach on the ground surface. Pumping drilling muds into a well to plug it is another method that has been used successfully for some time. Diverter wells are occasionally used, and sometimes simply pumping enough water on a well fire is sufficient to extinguish it. Of course, prevention is always the best solution. Many advances in blow-out prevention devices have been developed in the last 50 years and the number of fires has been substantially reduced compared to the number of wells drilled. However, very little in new technology has been applied to oil well fire fighting in the 1960s, 1970s, or 1980s. Overall technological progress has accelerated tremendously in this period, of course, but new materials and equipment were not applied to this field for some reason. Saddam Hussein`s environmental holocaust in Kuwait changed that by causing many people throughout the world to focus their creative energy on more efficient oil well fire fighting methods.

  15. Clinical study and image diagnosis of nasal bone fracture

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, Takenori; Suzuki, Naohiro; Okitsu, Takuji [Sendai City Hospital (Japan)

    2002-01-01

    In this study we reviewed the clinical features, diagnoses and treatments of 232 cases of nasal bone fracture cases treated at our department from January 1994 to June 2000. A marked predominance of males in the age range of 10-29 years was noted. Analysis of the causes of the nasal fractures were attributed to fighting (66 cases), traffic accidents (64 cases), sports (56 cases) and others (46 cases). The external appearance of nasal fractures were divided into 5 types, 85 cases of the displacement type, 27 cases of the depressed type, 32 of the mixed type, 56 of the non-deformation type and 32 of the unclassified type because of facial swelling. The sensitivity of conventional X-ray examination in identifying nasal fractures was 75.6%. Computed tomography scan (CT scan) was performed in 196 patients and showed that the middle and lower portions of nasal bones were fractured more easily than those of the upper portion. Nasal septum fracture occurred in 22 cases (11.2%). Other facial fractures combined with nasal fracture were found in 40 cases (20.4%). The type of combined fracture depended on the cause of the injury, for example, the combination of nasal and blow-out fracture was often caused by fighting, and many combined fractures of more than two facial bones resulted from traffic accidents. A total of 83 patients (35.8%) received reduction of the nasal bone fractures under general anaesthesia. The measurement of irradiation of each radiological examination revealed that the exposed dose of the newest model CT was similar to that of the conventional X-ray examination and tomography. (author)

  16. 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.

  17. 电力拖动的虚拟实验技术探讨

    Institute of Scientific and Technical Information of China (English)

    朱月华

    2014-01-01

    电子计算机技术的出现与发展,推动了科学的发展。伴随着计算机的发展,与电子计算机相关联的技术手段也如井喷式的涌现出来,而计算机仿真技术的诞生正是众多新技术其中之一。把仿真技术运用到电力拖动系统之中开展虚拟实验,将抽象化的理论直观的展现出来以便于理解。加之虚拟实验还拥有成本低与效率高的优点,因此在电力拖动系统中得以重视与使用。%The emergence of electronic computer technology and development, is the cross time in the history of science innovation. Along with the development of the computer, that is associated with the electronic computer technology also emerge such as blowout, and the birth of the computer simulation technology is one of many new technology. Apply the simulation technology to the electric drive system of virtual experiment, the abstract theory of intuitive display in order to facilitate understanding. Combined with the virtual experiment also has the advantages of low cost and high efifciency, therefore to pay attention to and the use in the electric drive system.

  18. Backspatter from experimental close-range shots to the head. I. Macrobackspatter.

    Science.gov (United States)

    Karger, B; Nüsse, R; Schroeder, G; Wüstenbecker, S; Brinkmann, B

    1996-01-01

    Backspatter is the ejection of biological material from a gunshot entrance wound against the line of fire. This phenomenon was investigated experimentally in transverse gunshots to the heads of calves (n = 9) using two types of 9 mm Parabellum ammunition from shooting distances of 0-10 cm. The resulting bloodstains were documented on white paper placed horizontally 60 cm below the impact site. In this report the analysis was restricted to stains with a diameter > 0.5 mm. Backspatter was documented after every gunshot. The number of stains varied from 31-324 per gunshot and appeared to be independent of the shooting distance. The maximum distance droplets travelled varied from 72-119 cm. The majority of droplets accumulated between 0 and 50 cm. The number of droplets and the distances travelled should be higher in man for anatomical reasons. The direction a single droplet can take comprises every possible angle between the most tangential ones to the skin surface. This resulted in a semi-circle of 180 degrees covered with stains. Skin ruptures of the entrance wound were not observed. The succession of events was documented on high speed film and started with the recoil of the firearm, immediately followed by a blow-out effect of the skin. Large droplets exited approximately 0.7-4 ms after the bullet impacted the skin. The calculated minimum initial velocity of these droplets was 13-61 m/s. Backspatter from gunshots to the head likely is caused by the hot gases expanding subcutaneously and by cavitation-related intracranial overpressure and tail splashing. In three out of nine gunshots, secondary backspatter additionally occurred as a result of droplets produced by a stream of blood from the entrance wound impacting the paper surface. PMID:8912050

  19. 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.

  20. Endangered species and cultural resources program, Naval Petroleum Reserves in California: Annual report FY95

    International Nuclear Information System (INIS)

    In FY95, EG and G Energy Measurements, Inc. (EG and G/EM) continued to support efforts to protect endangered species and cultural resources at the Naval Petroleum Reserves in California (NPRC). These efforts are conducted to ensure NPRC compliance with regulations regarding the protection of listed species and cultural resources on Federal properties. Population monitoring activities are conducted annually for San Joaquin kit foxes, giant kangaroo rats, blunt-nosed leopard lizards, and Hoover's wooly-star. To mitigate impacts of oil field activities on listed species, 674 preactivity surveys covering approximately 211 hectares (521 acres) were conducted in FY95. EG and G/EM also assisted with mitigating effects from third-party projects, primarily by conducting biological and cultural resource consultations with regulatory agencies. EG and G/EM has conducted an applied habitat reclamation program at NPRC since 1985. In FY95, an evaluation of revegetation rates on reclaimed and non-reclaimed disturbed lands was completed, and the results will be used to direct future habitat reclamation efforts at NPRC. In FY95, reclamation success was monitored on 50 sites reclaimed in 1985. An investigation of factors influencing the distribution and abundance of kit foxes at NPRC was initiated in FY94. Factors being examined include habitat disturbance, topography, grazing, coyote abundance, lagomorph abundance, and shrub density. This investigation continued in FY95 and a manuscript on this topic will be completed in FY96. Also, Eg and G/EM completed collection of field data to evaluate the effects of a well blow-out on plant and animal populations. A final report will be prepared in FY96. Finally, EG and G/EM completed a life table analysis on San Joaquin kit foxes at NPRC

  1. 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.

  2. Fatigue assessment of a double submerged arc welded gas pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Fazzini, Pablo; Otegui, Jose Luis [Universidad Nacional Mar del Plata, Mar del Plata (Argentina). Instituto de Ciencia y Tecnologia de Materiales (INTEMA); Teutonico, Mauricio; Manfredi, Carlos [GIE S.A., Mar del Plata (Argentina)

    2005-07-01

    An uncommon blowout in a 24'' diameter, 7 mm thick API 5L X52 gas pipeline was due to fracture at the longitudinal double submerged arc weld. Oddly enough for gas pipelines, it was found that fatigue cracks had propagated from a large embedded weld defect of lack of fusion resulting from severe geometrical mismatch between inner and outer weld passes. What makes this failure particularly interesting is that: previous in line inspections failed to detect any defect, no evidence of third party damage was found, and very few large pressure cycles had been recorded during the last 5 years of service, which were believed to be representative of the entire service life of the pipeline. Fatigue tests were carried out to characterize propagation of fatigue cracks in weld metal, it was found that a large Paris exponent made the few large amplitude cycles most contributing to crack propagation. Crack growth path and striation patterns were studied. Fatigue growth was modelled by integrating experimental results and by extrapolating striation spacing in the fracture surface of the failed pipe. Crack growth path and striation patterns were studied. It was found that microstructure discontinuities govern propagation at low {delta}K, but one striation per cycle was produced at large {delta}K, due to a mostly ductile propagation mode. Fatigue growth was modelled by integrating experimental results and by extrapolating striation spacing in the fracture surface of the failed pipe. It was found that in the early life of the line many more large pressure cycles than expected had occurred. Good correspondence between predicted and actual fatigue lives was in this way obtained (author)

  3. Mechanical stability of a salt cavern submitted to rapid pressure variations: Application to the underground storage of natural gas, compressed air and hydrogen

    International Nuclear Information System (INIS)

    Salt caverns used for the underground storage of large volumes of natural gas are in high demand given the ever-increasing energy needs. The storage of renewable energy is also envisaged in these salt caverns for example, storage of compressed air and hydrogen mass storage. In both cases, salt caverns are more solicited than before because they are subject to rapid injection and withdrawal rates. These new operating modes raise new mechanical problems, illustrated in particular by sloughing, and falling of overhanging blocks at cavern wall. Indeed, to the purely mechanical stress related to changes in gas pressure variations, repeated dozens of degrees Celsius of temperature variation are superimposed; causes in particular during withdrawal, additional tensile stresses whom may lead to fractures at cavern wall; whose evolution could be dangerous. The mechanical behavior of rock salt is known: it is elasto-viscoplastic, nonlinear and highly thermo sensitive. The existing rock salt constitutive laws and failures and damages criteria have been used to analyze the behavior of caverns under the effects of these new loading. The study deals with the thermo mechanics of rocks and helps to analyze the effects of these new operations modes on the structural stability of salt caverns. The approach was to firstly design and validate a thermodynamic model of the behavior of gas in the cavern. This model was used to analyze blowout in gas salt cavern. Then, with the thermo mechanical coupling, to analyze the effects of rapid withdrawal, rapid injection and daily cycles on the structural stability of caverns. At the experimental level, we sought the optimal conditions to the occurrence and the development of cracks on a pastille and a block of rock salt. The creep behavior of rock salt specimens in triaxial extension also was analyzed. (author)

  4. 颈部大动脉出血急救及血管修复重建(附6例11次报告)%Emergency rescue and vascular reconstruction of carotid artery rupture: a report of 6 cases

    Institute of Scientific and Technical Information of China (English)

    朱敏辉; 郑宏良; 陈世彩; 陈东辉

    2012-01-01

    primary illness included vocal cord paralysis (2 cases) after operation of thyroid carcinoma, recurrent thyroid carcinoma (1 case), recurrent hypopharyngeal carcinoma (1 case), head and neck trauma (1 case) and carotid body tumord case). Four patients received radiotherapy (60-80 Gy) before second operation. One patient (2 times) had innominate artery blowout, 4 (8 times) had common carotid blowout, and one had internal carotid artery blowout. CAR occurred during or after surgical operations in 4 patients (8 times) and was caused by external injury in 1 case (1 time). Results Restore of CA after complete exposure of rupture was performed for 5 times, anastomosis by artificial blood vessel for 1 time, direct anastomosis for 1 time, reconstruction by great saphenous vein for 2 times, and ligation of total carotid artery for 2 times. Of all patients, 3 cases undergoing vascular reconstruction succeeded by one try, 2 by 2 tries, and 2 cases underwent ligation of artery because of suture falling off for radiotherapy of infection. Muscle flaps including pectoralis major myocutaneous flap ( 3 cases ) and sternocleidomastoid faps (2 cases) were used to protect vascular anastomosis. All cases were successfully rescued, without perioperative death. One patient developed hemiplegial after ligation of carotid artery. All cases had complete follow-up data. One patient died due to bleeding one week after discharge, 1 died due to recurrent tumor within one year after operation. By now one patient survived for 3 years and 3 for 5 years. Conclusion Once CAP occurs, prompt press by hands and quick anti-shock procedure are the prerequisites of successful rescue. Reconstruction or repair of carotid artery can prevent complications of the nervous system, and individualized vascular reconstruction strategy should be employed. Ligation of carotid is effective to rescue patients of CAR, but it should only be chosen when reconstruction is impossible.

  5. 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

  6. Passive remote sensing of large-scale methane emissions from Oil Fields in California's San Joaquin Valley and validation by airborne in-situ measurements - Results from COMEX

    Science.gov (United States)

    Gerilowski, Konstantin; Krautwurst, Sven; Thompson, David R.; Thorpe, Andrew K.; Kolyer, Richard W.; Jonsson, Haflidi; Krings, Thomas; Frankenberg, Christian; Horstjann, Markus; Leifer, Ira; Eastwood, Michael; Green, Robert O.; Vigil, Sam; Fladeland, Matthew; Schüttemeyer, Dirk; Burrows, John P.; Bovensmann, Heinrich

    2016-04-01

    detection limit. This opens new applications of airborne atmospheric remote sensing in the area of anthropogenic top-down emission monitoring as well as for atmospheric CH4 leakage monitoring during accidents like the Elgin blow-out (March 2012) in the North Sea or the recent Aliso Canyon gas leak incident (2015/2016) in California.

  7. 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.

  8. Radiological and toxicological analyses of tank 241-AY-102 and tank 241-C-106 ventilation systems

    Energy Technology Data Exchange (ETDEWEB)

    Himes, D.A.

    1998-08-11

    The high heat content solids contained in Tank 241-C-106 are to be removed and transferred to Tank 241-AY-102 by sluicing operations, to be authorized under project W320. While sluicing operations are underway, the state of these tanks will be transformed from unagitated to agitated. This means that the partition fraction which describes the aerosol content of the head space will increase from IE-10 to IE-8 (see WHC-SD-WM-CN062, Rev. 2 for discussion of partition fractions). The head spare will become much more loaded with suspended material. Furthermore, the nature of this suspended material can change significantly: sluicing could bring up radioactive solids which normally would lay under many meters of liquid supernate. It is assumed that the headspace and filter aerosols in Tank 241-AY-102 are a 90/10 liquid/solid split. It is further assumed that the sluicing line, the headspace in Tank 241-C-106, and the filters on Tank 241-C-106 contain aerosols which are a 67/33 liquid/solid split. The bases of these assumptions are discussed in Section 3.0. These waste compositions (referred to as mitigated compositions) were used in Attachments 1 through 4 to calculate survey meter exposure rates per liter of inventory in the various system components. Three accident scenarios are evaluated: a high temperature event which melts or burns the HEPA filters and causes releases from other system components; an overpressure event which crushes and blows out the HEPA filters and causes releases from other system components; and an unfiltered release of tank headspace air. The initiating event for the high temperature release is a fire caused by a heater malfunction inside the exhaust dust or a fire outside the duct. The initiating event for the overpressure event could be a steam bump which over pressurizes the tank and leads to a blowout of the HEPA filters in the ventilation system. The catastrophic destruction of the HEPA filters would release a fraction of the accumulated

  9. Creation of a neo-aortoiliac system from lower extremity deep and superficial veins.

    Science.gov (United States)

    Clagett, G P; Bowers, B L; Lopez-Viego, M A; Rossi, M B; Valentine, R J; Myers, S I; Chervu, A

    1993-01-01

    OBJECTIVE: This study evaluated the morbidity, mortality, and intermediate term follow-up of patients undergoing replacement of their aortoiliac-femoral systems with lower extremity deep and superficial veins. SUMMARY BACKGROUND DATA: The most commonly used treatment for aortic prosthetic infection is ectopic bypass and removal of the prosthesis. The overall mortality rate with this approach is approximately 20%, with an amputation rate of 10% to 14%. Other limitations include thrombosis of the ectopic bypass leading to limb loss, reinfection of the ectopic bypass, and aortic stump blowout. Dissatisfaction with this approach has led the authors to develop the following. METHODS: A neo-aortoiliac system (NAIS) was fashioned from lower extremity deep veins (DV), greater saphenous veins (GSV), or both in patients with infected aortobifemoral prosthesis (n = 17) and other complex aortic problems (n = 3). Removal of infected prosthetic material, harvest of vein, and creation of NAIS was performed as a single-staged procedure. RESULTS: The in-hospital mortality and amputation rates were 10% each. The mean (+/- standard deviation [SD]) operative time was 6.5 +/- 1.8 hours and the blood transfusion requirement was 4 +/- 3 units. Four patients experienced postoperative gastrointestinal complications with peritonitis and sepsis; NAIS vein graft resisted infection and remained intact. The mean follow-up time was 22.5 +/- 16 months. NAISs constructed from GSVs were prone to the development of focal stenoses requiring intervention or diffuse neointimal hyperplasia leading to occlusion. In contrast, all NAISs from larger caliber DVs have remained widely patent. The failure rate of GSV NAISs was 64%, compared to 0% for DV NAISs (p = 0.006). Despite the high failure rate in patients with GSV NAISs, none has required amputation. In patients who had DVs harvested for NAIS reconstruction, limb edema and other signs of venous hypertension have been minimal. CONCLUSION: NAIS

  10. Simulations of the formation and evolution of isolated dwarf galaxies

    Science.gov (United States)

    Valcke, S.; de Rijcke, S.; Dejonghe, H.

    2008-09-01

    We present new fully self-consistent models of the formation and evolution of isolated dwarf galaxies (DGs). We have used the publicly available N-body/smoothed particle hydrodynamics (SPH) code HYDRA, to which we have added a set of star formation criteria, and prescriptions for chemical enrichment [taking into account contributions from both Type Ia supernova (SNIa) and Type II supernova (SNII)], supernova feedback, and gas cooling. We extensively tested the soundness of these prescriptions and the numerical convergence of the models. The models follow the evolution of an initially homogeneous gas cloud collapsing in a pre-existing dark matter (DM) halo. These simplified initial conditions are supported by the merger trees of isolated DGs extracted from the milli-Millennium Simulation. The star formation histories (SFHs) of the model galaxies exhibit burst-like behaviour. These bursts are a consequence of the blow-out and subsequent in-fall of gas. The amount of gas that leaves the galaxy for good is found to be small, in absolute numbers, ranging between 3 × 107 and 6 × 107Msolar. For the least massive models, however, this is over 80 per cent of their initial gas mass. The local fluctuations in gas density are strong enough to trigger starbursts in the massive models, or to inhibit anything more than small residual star formation (SF) for the less massive models. Between these starbursts there can be time intervals of several gigayears. The models' surface brightness profiles are well fitted by Sérsic profiles and the correlations between the models' Sérsic parameters and luminosity agree with the observations. We have also compared model predictions for the half-light radius Re, central velocity dispersion σc, broad-band colour B - v, metallicity [Z/Zsolar] versus luminosity relations and for the location relative to the fundamental plane with the available data. The properties of the model DGs agree quite well with those of observed DGs. However, the

  11. Correspondence Between “Stable” Flame Macrostructure and Thermo-acoustic Instability in Premixed Swirl-Stabilized Turbulent Combustion

    KAUST Repository

    Taamallah, Soufien

    2014-12-23

    Copyright © 2015 by ASME. In this paper, we conduct an experimental investigation to study the link between the flame macroscale structure - or flame brush spatial distribution - and thermo-acoustic instabilities, in a premixed swirl-stabilized dump combustor. We operate the combustor with premixed methane-air in the range of equivalence ratio (Φ) from the lean blowout limit to Φ = 0. 75. First, we observe the different dynamic modes in this lean range as Φ is raised. We also document the effect of Φ on the flame macrostructure. Next, we examine the correspondence between dynamic mode transitions and changes in flame macrostructure. To do so, we modify the combustor length - by downstream truncation - without changing the underlying flow upstream. Thus, the resonant frequencies of the geometry are altered allowing for decoupling the heat release rate fluctuations and the acoustic feedback. Mean flame configurations in the modified combustor and for the same range of equivalence ratio are examined, following the same experimental protocol. It is found that not only the same sequence of flame macrostructures is observed in both combustors but also that the transitions occur at a similar set of equivalence ratio. In particular, the appearance of the flame in the outside recirculation zone (ORZ) in the long combustor - which occurs simultaneously with the onset of instability at the fundamental frequency - happens at similar Φ when compared to the short combustor, but without being in latter case accompanied by a transition to thermo-acoustic instability. Then, we interrogate the flow field by analyzing the streamlines, mean, and rms velocities for the nonreacting flow and the different flame types. Finally, we focus on the transition of the flame to the ORZ in the acoustically decoupled case. Our analysis of this transition shows that it occurs gradually with an intermittent appearance of a flame in the ORZ and an increasing probability with Φ. The spectral

  12. First riser drilling in Scientific Ocean Drilling history, Observatory drilling and casing in the Nankai Trough (IODP Exp 319)

    Science.gov (United States)

    Toczko, S.; Eguchi, N. O.; Takahashi, K.; Araki, E.; Byrne, T. B.; McNeill, L. C.; Saffer, D. M.

    2009-12-01

    IODP Expedition 319 (“Riser and Riserless Observatory-1”, NanTroSEIZE Stage 2) was the first time in IODP history that scientific riser operations were conducted. As part of this groundbreaking advance in scientific drilling, other technologies and sampling methods were also introduced: scientific mud-gas monitoring, drilling cuttings collection and analysis, MDT, and VSP (walk-away and zero-offset). Although the goals and achievements for Expedition 319 were modest, we will describe the operational portions of these technologies, and also discuss the potential and benefits of future riser drilling operations. JAMSTEC’s Center for Deep Earth Exploration (CDEX), the Japanese Implementing Organization and operator of the riser drillship Chikyu, this year performed the inaugural riser drilling expedition for IODP, as part of NanTroSEIZE Stage 2, Expedition 319, “Riser and Riserless Observatories”. Riser drilling is a typical method of drilling in industry, since it helps prevent loss of petroleum while drilling at sea, and also allows for deeper drilling depths, when compared with the usual non-riser drilling. The system aboard Chikyu is an industrial design riser system, which has just completed drilling operations in the Kumano Basin, drilling and casing a riser hole, Hole C0009A, to 1607.3 mBSF in water 2054 m BSL deep. The riser drilling system maintains a connection between the riser pipe suspended from the drillship to the sea floor blowout preventer (BOP), which makes a seal between the riser pipe and well head, and below to the cased intervals of the borehole below the seafloor. This allows the drilling mud to circulate down through the drillpipe, out the bit, and back up the casing and riser pipe to the drillship. This cools the bit, clears the borehole of cuttings (recovered aboard ship in the shale shakers) and allows real-time mud-gas monitoring. Mud weight can be more carefully controlled and adjusted, improving the quality of mudcake on the

  13. NO TRACE LEFT BEHIND: STEREO OBSERVATION OF A CORONAL MASS EJECTION WITHOUT LOW CORONAL SIGNATURES

    International Nuclear Information System (INIS)

    The availability of high-quality synoptic observations of the extreme-ultraviolet (EUV) and visible corona during the SOHO mission has advanced our understanding of the low corona manifestations of coronal mass ejections (CMEs). The EUV imager/white light coronagraph connection has been proven so powerful, it is routinely assumed that if no EUV signatures are present when a CME is observed by a coronagraph, then the event must originate behind the visible limb. This assumption carries strong implications for space weather forecasting but has not been put to the test. This paper presents the first detailed analysis of a frontside, large-scale CME that has no obvious counterparts in the low corona as observed in EUV and Hα wavelengths. The event was observed by the SECCHI instruments onboard the STEREO mission. The COR2A coronagraph observed a slow flux-rope-type CME, while an extremely faint partial halo was observed in COR2B. The event evolved very slowly and is typical of the streamer-blowout CME class. EUVI A 171 A images show a concave feature above the east limb, relatively stable for about two days before the eruption, when it rises into the coronagraphic fields and develops into the core of the CME. None of the typical low corona signatures of a CME (flaring, EUV dimming, filament eruption, waves) were observed in the EUVI B images, which we attribute to the unusually large height from which the flux rope lifted off. This interpretation is supported by the CME mass measurements and estimates of the expected EUV dimming intensity. Only thanks to the availability of the two viewpoints we were able to identify the likely source region. The event originated along a neutral line over the quiet-Sun. No active regions were present anywhere on the visible (from STEREO B) face of the disk. Leaving no trace behind on the solar disk, this observation shows unambiguously that a CME eruption does not need to have clear on-disk signatures. Also it sheds light on the

  14. DRSPALL :spallings model for the Waste Isolation Pilot Plant 2004 recertification

    International Nuclear Information System (INIS)

    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

  15. A discussion on the criteria for quantitative risk analysis of sour gas wells%含硫气井定量风险分析技术标准探讨

    Institute of Scientific and Technical Information of China (English)

    吴庆善; 钱新明; 郭再富

    2009-01-01

    With the development of many sour gas fields in succession in China, it is urgent and necessary to establish the regulatory criteria of safety, especially of quantitative risk analysis, for sour gas wells. Therefore, through analysis on the principle, application scope, and the framework of the establishment of the quantitative risk analysis on sour gas wells, a meth-od of numerical statistical analysis with the reference values were presented on the accidental probability of well blowouts under the national condition, as well as the method and requirements of consequence analysis after accidents, and some key technical parameters and main contents of the calculating methods of quantitative risk analysis and the acceptable risk level, etc. This provides guidance for the establishment of the criteria for quantitative risk analysis of sour gas wells, and impels the quantita-tive risk evaluation and management to be possibly performed in sour gas fields of China.%随着近年来我国众多含硫化氢气田相继投入开发,含硫气井安全规划标准,特别是定量风险分析标准的制订变得十分必要和迫切.为此,分别对含硫气井定量风险分析技术标准的制订原则、适用范围、框架结构进行了分析,提出了适合我国国情的井喷事故概率的数值统计分析方法及参考值,事故后果分析方法及要求,定量风险计算方法及可接受风险水平等关键技术参数及主要技术内容.研究成果可用于指导我国含硫气井定量风险分析标准的制订,将使我国对含硫气田开发实施定量风险评价和管理成为可能.

  16. Engineering geology studies in the National Petroleum Reserve, Alaska

    Science.gov (United States)

    Kachadoorian, Reuben; Crory, F.E.

    1984-01-01

    Engineering geology studies were conducted in direct support of the exploration program in the National Petroleum Reserve, Alaska. The studies included laboratory and field tests and observations to address design and construction problems of airfields, roads, drill pads and foundations, and to evaluate their actual performance. Permafrost containing large amounts of near surface ground ice as wedges, masses, and intergranular ice, required that all construction activity not disturb the thermal regime of the ground surface, which could lead to thaw of permafrost and ground subsidence. Summer activity, therefore was not allowable, yet the winter climate was so harsh that winter work was slow and inefficient. To allow summer operations at well sites planned for all year activity, it was necessary to adapt existing techniques for arctic construction and to devise new ones. The design and construction of facilities at the deep exploration wells at Inigok, Tunalik, and Lisburne posed the greatest challenge. These sites, requiring a year or more to drill, could only be attempted if continuous access to drilling and logistic supplies could be assured throughout the year, including the possibility of bringing in another drill rig, in the event of a blowout. Thus all-seasons airstrips were required at these wells. Sufficient quantities of local gravel were not readily available at the Inigok and Tunalik sites to construct the airstrips with the required 6 feet or more of gravel to prevent the underlying permafrost from thawing. Therefore, insulation was used to maintain the subbase of local sands in a continuously frozen state, which in turn was overlain by 15 inches of gravel or sandy gravel. Tests at the U.S. Army Waterways Experimental Station defined the minimum thickness of gravel required above the insulation to provide the desired bearing capacity for the C-130 type aircraft without crushing the insulation. Field testing also included the evaluation of another design

  17. Disk radii and grain sizes in Herschel-resolved debris disks

    International Nuclear Information System (INIS)

    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

  18. Model-Based Hookload Monitoring and Prediction at Drilling Rigs using Neural Networks and Forward-Selection Algorithm

    Science.gov (United States)

    Arnaout, A.; Fruhwirth, R.; Winter, M.; Esmael, B.; Thonhauser, G.

    2012-04-01

    The use of neural networks and advanced machine learning techniques in the oil & gas industry is a growing trend in the market. Especially in drilling oil & gas wells, prediction and monitoring different drilling parameters is an essential task to prevent serious problems like "Kick", "Lost Circulation" or "Stuck Pipe" among others. The hookload represents the weight load of the drill string at the crane hook. It is one of the most important parameters. During drilling the parameter "Weight on Bit" is controlled by the driller whereby the hookload is the only measure to monitor how much weight on bit is applied to the bit to generate the hole. Any changes in weight on bit will be directly reflected at the hookload. Furthermore any unwanted contact between the drill string and the wellbore - potentially leading to stuck pipe problem - will appear directly in the measurements of the hookload. Therefore comparison of the measured to the predicted hookload will not only give a clear idea on what is happening down-hole, it also enables the prediction of a number of important events that may cause problems in the borehole and yield in some - fortunately rare - cases in catastrophes like blow-outs. Heuristic models using highly sophisticated neural networks were designed for the hookload prediction; the training data sets were prepared in cooperation with drilling experts. Sensor measurements as well as a set of derived feature channels were used as input to the models. The contents of the final data set can be separated into (1) features based on rig operation states, (2) real-time sensors features and (3) features based on physics. A combination of novel neural network architecture - the Completely Connected Perceptron and parallel learning techniques which avoid trapping into local error minima - was used for building the models. In addition automatic network growing algorithms and highly sophisticated stopping criterions offer robust and efficient estimation of the

  19. The potentialities of ground-penetrating radar in the engineering geology using the radars GROT-12 and GROT-12E

    Science.gov (United States)

    Volkomirskaya, Liudmila; Gulevich, Oxana; Musalev, Dmitri

    2013-04-01

    The potentialities of ground-penetrating radar in the engineering geology using the radars GROT-12 and GROT-12E L.B. Volkomirskaya(1,2), O.A. Gulevich(1,2), D.N. Musalev(3) 1. IZMIRAN, 142190, Russia, Moscow, Troitsk, Kalugskoe 4 2. ZAO Timer, 142190, Russia, Moscow, Troitsk, Lesnaya str. 4B 3. OAO Belgorchemprom, Republic of Belarus, Minsk, Masherov str. 17 The article presents the potentialities of ground-penetrating radar in the engineering geology on the basis of the latest modifications of the GPR "GROT": the low-frequency GPR GROT-12 and the high-frequency GPR GROT-12E. The article gives technical specifications of the GPRs GROT-12 and GROT-12E and their particular characteristics that define them from analogues. The solutions of direct problems of ground penetrating radar on the basis of Maxwell's equations in general formulation with given wide-band signal source are confronted to experimental data received from different fields of the engineering geology, for example: 1. To secure mining in salt mines the method was adapted to locate in the working layers the investigating boreholes, fault lines, borders of displacement and blowout of productive layers, as well as working pits without access. 2. To monitor the reinforced concrete structures of airport runways the technology was worked out to collect and process GPR data so as to locate communications under the runways and examine basement condition. 3. To carry out the reconstruction of buildings and pre-project engineering geological works the GPR shooting technology was improved to process the examinations of the bearing capacity of soils and to locate lost communications. 4. To perform ecological monitoring of abandoned mines the technology of the GPR data collecting and processing was developed to assess the conditions of stowage materials in mouths of destroyed vertical mine shafts, the location of inclined mine shafts, the determination of hollow spaces and thinning zones, the localization of ground

  20. 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