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. 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. ...

  4. Gastric blow-out: komplikation efter fedmekirurgi

    DEFF Research Database (Denmark)

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

    2009-01-01

    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......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...

  5. 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...

  6. Surgical timing of the orbital "blowout" fracture

    DEFF Research Database (Denmark)

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

    2016-01-01

    Objective: The orbital blowout fracture is a common facial injury, carrying with it a risk of visual impairment and undesirable cosmetic results unless treated properly. Optimal timing of the surgical treatment is still a matter of debate. We set out to determine whether a meta-analysis would bring......). Patients were evaluated for diplopia and enophthalmos.  Review Methods: We followed the statements of PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses). Pooled odds ratios were estimated with the fixed effects method of Mantel-Haenszel.  Results: We identified 5 studies...

  7. Inline Repair of Blowouts During Laser Welding

    Science.gov (United States)

    Hansen, K. S.; Olsen, F. O.; Kristiansen, M.; Madsen, O.

    In a current laser welding production process of components of stainless steel, a butt joint configuration may lead to failures in the form of blowouts, causing an unacceptable welding quality. A study to improve the laser welding process was performed with the aim of solving the problem by designing a suitable pattern of multiple small laser spots rather than a single spot in the process zone. The blowouts in the process are provoked by introducing small amounts of zinc powder in the butt joint. When the laser heats up the zinc, this rapidly evaporates and expands, leaving the melt pool to be blown away locally. Multiple spot pattern designs are tested. Spot patterns are produced by applying diffractive optics to a beam from a single mode fiber laser. Results from welding while applying spot patterns both with and without trailing spots are presented. Data showing the power ratio between a trailing spot and two main spots as a function of spot distance is also presented. The results of the study show that applying multiple spots in the welding process may improve the process stability when welding materials with small impurities in the form of zinc particles.

  8. Development of 3000 m Subsea Blowout Preventer Experimental Prototype

    Science.gov (United States)

    Cai, Baoping; Liu, Yonghong; Huang, Zhiqian; Ma, Yunpeng; Zhao, Yubin

    2017-12-01

    A subsea blowout preventer experimental prototype is developed to meet the requirement of training operators, and the prototype consists of hydraulic control system, electronic control system and small-sized blowout preventer stack. Both the hydraulic control system and the electronic system are dual-mode redundant systems. Each system works independently and is switchable when there are any malfunctions. And it significantly improves the operation reliability of the equipment.

  9. Fluid Mechanics of Lean Blowout Precursors in Gas Turbine Combustors

    Directory of Open Access Journals (Sweden)

    T. M. Muruganandam

    2012-03-01

    Full Text Available Understanding of lean blowout (LBO phenomenon, along with the sensing and control strategies could enable the gas turbine combustor designers to design combustors with wider operability regimes. Sensing of precursor events (temporary extinction-reignition events based on chemiluminescence emissions from the combustor, assessing the proximity to LBO and using that data for control of LBO has already been achieved. This work describes the fluid mechanic details of the precursor dynamics and the blowout process based on detailed analysis of near blowout flame behavior, using simultaneous chemiluminescence and droplet scatter observations. The droplet scatter method represents the regions of cold reactants and thus help track unburnt mixtures. During a precursor event, it was observed that the flow pattern changes significantly with a large region of unburnt mixture in the combustor, which subsequently vanishes when a double/single helical vortex structure brings back the hot products back to the inlet of the combustor. This helical pattern is shown to be the characteristic of the next stable mode of flame in the longer combustor, stabilized by double helical vortex breakdown (VBD mode. It is proposed that random heat release fluctuations near blowout causes VBD based stabilization to shift VBD modes, causing the observed precursor dynamics in the combustor. A complete description of the evolution of flame near the blowout limit is presented. The description is consistent with all the earlier observations by the authors about precursor and blowout events.

  10. Flame Color as a Lean Blowout Predictor

    Directory of Open Access Journals (Sweden)

    Rajendra R. Chaudhari

    2013-03-01

    Full Text Available The study characterizes the behavior of a premixed swirl stabilized dump plane combustor flame near its lean blow-out (LBO limit in terms of CH* chemiluminiscence intensity and observable flame color variations for a wide range of equivalence ratio, flow rates and degree of premixing (characterized by premixing length, Lfuel. LPG and pure methane are used as fuel. We propose a novel LBO prediction strategy based solely on the flame color. It is observed that as the flame approaches LBO, its color changes from reddish to blue. This observation is found to be valid for different levels of fuel-air premixing achieved by changing the available mixing length of the air and the fuel upstream of the dump plane although the flame dynamics were significantly different. Based on this observation, the ratio of the intensities of red and blue components of the flame as captured by a color CCD camera was used as a metric for detecting the proximity of the flame to LBO. Tests were carried out for a wide range of air flow rates and using LPG and CH4 as fuel. For all the operating conditions and both fuels tested, this ratio was found to monotonically decrease as LBO was approached. Moreover, the value of this ratio was within a small range close to LBO for all the cases investigated. This makes the ratio suitable as a metric for LBO detection at all levels of premixing.

  11. 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.

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

    International Nuclear Information System (INIS)

    Lu Hsuehju; Chen Kuowei; Chen Minghuang; Tzeng Chenghwai; Chang Peter Muhsin; Yang Muhhwa; Chu Penyuan; Tai Shyhkuan

    2013-01-01

    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 (albumin 1000 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)

  13. Three years of morphologic changes at a bowl blowout, Cape Cod, USA

    Science.gov (United States)

    Smith, Alex; Gares, Paul A.; Wasklewicz, Thad; Hesp, Patrick A.; Walker, Ian J.

    2017-10-01

    This study presents measurements of blowout topography obtained with annual terrestrial laser surveys carried out over a three-year period at a single, large bowl blowout located in the Provincelands Dunes section of Cape Cod National Seashore, in Massachusetts. The study blowout was selected because its axis is aligned with northwest winds that dominate the region, and because it was seemingly interacting with a smaller saucer blowout that had recently formed on the southern rim of the primary feature. Assuming that blowouts enlarge both horizontally and vertically in response to the wind regime, the objectives of the study were to determine both the amount of horizontal growth that the blowout experiences annually and the spatial patterns of vertical change that occur within the blowout. Changes to the blowout lobe surrounding the feature were also determined for areas with sparse enough vegetation cover to allow laser returns from the sand surface. The results show that the blowout consistently expanded outward during the three years, with the greatest expansion occurring at its southeast corner, opposite the prevailing winds. The most significant occurrence was the removal, in the first year, of the ridge that separated the two blowouts, resulting in a major horizontal shift of the southern rim of the new combined blowout. This displacement then continued at a lesser rate in subsequent years. The rim also shifted horizontally along the northwest to northeast sections of the blowout. Significant vertical loss occurred along the main axis of the blowout with the greatest loss concentrated along the southeast rim. On the lobe, there were large areas of deposition immediately downwind of the high erosion zones inside the blowout. However, there were also small erosion areas on the lobe, extending downwind from eroding sections of the rim. This study shows that: 1. blowouts can experience significant areal and volumetric changes in short periods of time; 2

  14. 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.

  15. Well blowout rates in California Oil and Gas District 4--Update and Trends

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, Preston D.; Benson, Sally M.

    2009-10-01

    Well blowouts are one type of event in hydrocarbon exploration and production that generates health, safety, environmental and financial risk. Well blowouts are variously defined as 'uncontrolled flow of well fluids and/or formation fluids from the wellbore' or 'uncontrolled flow of reservoir fluids into the wellbore'. Theoretically this is irrespective of flux rate and so would include low fluxes, often termed 'leakage'. In practice, such low-flux events are not considered well blowouts. Rather, the term well blowout applies to higher fluxes that rise to attention more acutely, typically in the order of seconds to days after the event commences. It is not unusual for insurance claims for well blowouts to exceed US$10 million. This does not imply that all blowouts are this costly, as it is likely claims are filed only for the most catastrophic events. Still, insuring against the risk of loss of well control is the costliest in the industry. The risk of well blowouts was recently quantified from an assembled database of 102 events occurring in California Oil and Gas District 4 during the period 1991 to 2005, inclusive. This article reviews those findings, updates them to a certain extent and compares them with other well blowout risk study results. It also provides an improved perspective on some of the findings. In short, this update finds that blowout rates have remained constant from 2005 to 2008 within the limits of resolution and that the decline in blowout rates from 1991 to 2005 was likely due to improved industry practice.

  16. Complete inferior rectus muscle transection secondary to orbital blowout fracture.

    Science.gov (United States)

    Carrere, Jonathan M; Lewis, Kyle T

    2018-01-05

    Complete extraocular muscle transection is uncommon in the setting of blunt trauma. We report a case of a 53-year-old male that developed diplopia after hitting his face directly on a concrete slab after a fall. On examination, he had a right hypertropia with a complete infraduction deficit. A CT scan of the face showed an orbital floor blowout fracture with complete inferior rectus transection. On surgical exploration, the distal and proximal ends of the muscle were identified and sutured together, and the floor fracture was repaired. At his post-operative visits, the patient had a persistent infraduction deficit, but subjectively had improved diplopia.

  17. Self expandable polytetrafluoroethylene stent for carotid blowout syndrome.

    Science.gov (United States)

    Tatar, E C; Yildirim, U M; Dündar, Y; Ozdek, A; Işik, E; Korkmaz, H

    2012-01-01

    Carotid blowout syndrome (CBS) is an emergency complication in patients undergoing treatment for head and neck cancers. The classical management of CBS is the ligation of the common carotid artery, because suturing is not be possible due to infection and necrosis of the field. In this case report, we present a patient with CBS, in whom we applied a self-expandable polytetrafluoroethylene (PTFE) stent and observed no morbidity. Endovascular stent is a life-saving technique with minimum morbidity that preserves blood flow to the brain. We believe that this method is preferable to ligation of the artery in CBS.

  18. Dynamic Changes of Typical Blowouts Based on High-Resolution Data: A Case Study in Hulunbuir Sandy Land, China

    Directory of Open Access Journals (Sweden)

    Yi Yang

    2017-01-01

    Full Text Available Blowouts are an important ground indication of wind-sand activity in the Hulunbuir grassland. They include two basic geomorphologic units, erosion depression and sand deposition, and three typical morphological types: saucer type, trough type, and compound type. In this study, the dynamic changes of typical blowouts within the past decade were analyzed via multiperiod high-resolution remote sensing images. RTK was used to repeatedly measure the blowouts to obtain their high-precision 3D terrain data in 2010, 2011, and 2012. Short-term dynamic changes in 3D blowout morphology were carefully analyzed to discover the following. (1 From 2002 to 2012, the depressions of typical blowouts exhibited downwind extension and lateral expansion trends, as they continuously grew in size. Regarding the sand deposition zones, those of the saucer blowout grew continuously, while those of the trough and compound blowouts fluctuated between growth and contraction. (2 The erosion depression of saucer blowouts eroded downward and spread horizontally; that of trough blowouts first accumulated then eroded but also spread horizontally. The erosion depression of compound blowouts exhibited horizontal spreading accompanied with bottom accumulation. The sand deposition zones of all three types of blowouts exhibited decreasing length with increasing width and height.

  19. A Slow Streamer Blowout at the Sun and Ulysses

    Science.gov (United States)

    Seuss, S. T.; Bemporad, A.; Poletto, G.

    2004-01-01

    On 10 June 2000 a streamer on the southeast limb slowly disappeared from LASCO/C2 over approximately 10 hours. A small CME was reported in C2. A substantial interplanetary CME (ICME) was later detected at Ulysses, which was at quadrature with the Sun and SOHO at the time. This detection illustrates the properties of an ICME for a known solar source and demonstrates that the identification can be done even beyond 3 AU. Slow streamer blowouts such as this have long been known but are little studied. We report on the SOHO observation of a coronal mass ejection (CME) on the solar limb and the subsequent in situ detection at Ulysses, which was near quadrature at the time, above the location of the CME. SOHO-Ulysses quadrature was 13 June, when Ulysses was 3.36 AU from the Sun and 58.2 degrees south of the equator off the east limb. The slow streamer blowout was on 10 June, when the SOHO-Sun-Ulysses angle was 87 degrees.

  20. Orbital Wall Restoring Surgery in Pure Blowout Fractures

    Directory of Open Access Journals (Sweden)

    Nam Kyu Lim

    2014-11-01

    Full Text Available BackgroundRestoring orbital volume in large blowout fractures is still a technically challenge to the orbital surgeon. In this study, we restored the orbital wall using the combination of transorbital and transnasal approach with additional supports from the paranasal sinuses, and we compared the surgical outcome to that of a conventional transorbital method.MethodsA retrospective review of all patients with pure unilateral blowout fractures between March 2007 and March 2013 was conducted. 150 patients were classified into two groups according to the surgical method: conventional transorbital method (group A, 75 patients, control group, and the combination of transorbital and transnasal approach with additional supports from the paranasal sinuses (group B, 75 patients, experimental group. Each group was subdivided depending on fracture location: group I (inferior wall, group IM (inferomedial wall, and group M (medial wall. The surgical results were assessed by the Hertel scale and a comparison of preoperative and postoperative orbital volume ratio (OVR values.ResultsIn the volumetric analysis, the OVR decreased more by the experimental groups than each corresponding control groups (P0.05.ConclusionsOur surgical results suggest that orbital volume was more effectively restored by the combination of transorbital and transnasal approach with additional supports from the paranasal sinuses than the conventional method, regardless of the type of fracture.

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

    Science.gov (United States)

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

    2010-04-01

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

  2. Simple Repair of a Blow-Out Fracture by the Modified Caldwell-Luc Approach.

    Science.gov (United States)

    Park, Min Woo; Kim, Soung Min; Amponsah, Emmanuel Kofi; Lee, Suk Keun

    2015-06-01

    Here we report a patient with a blow-out fracture of the orbital floor that was treated by an intraoral transmaxillary approach. This 38-year-old man suffered a sudden blow to the periorbital area, which caused prolapse of the orbital contents into the maxillary sinus. The modified Caldwell-Luc approach was used to repair the orbital blow-out fracture and the maxillary sinus during was packed with Frazin gauze for 7 days to prevent recurrence of the prolapse. This was an easy and minimally invasive technique for the management of a blow-out fracture of the orbital floor.

  3. BLOWOUT FRACTURES OF THE FLOOR OF THE ORBIT.

    Science.gov (United States)

    MORTON, W R; TURNBULL, W

    1964-01-11

    Blowout fractures of the orbit, a frequent complication of midfacial trauma, result from an increased intraorbital pressure which "blows out" the weakest area-the floor. Intraorbital fat and muscles herniated into the maxillary sinus, muscles incarcerated in the fracture, and the displaced orbital contents produce diplopia. After incarceration, elevation of the affected eye is impossible.Diagnosis is frequently difficult because initial intraorbital hemorrhage may limit mobility. Tomograms in the Waters' projection may show the fracture but frequently reveal only a cloudy antrum. The muscle traction test described herein is most helpful.The surgical correction aims at bridging the defect with Teflon or stainless-steel mesh or endogenous bone graft placed beneath the periosteum. Entry is gained through the lower lid. If repaired early, there is no functional loss and the repair is cosmetically excellent.

  4. Flame Propagation and Blowout in Hydrocarbon Jets: Experiments to Understand the Stability and Structure

    Science.gov (United States)

    2012-07-29

    Wilson and Kevin M. Lyons. On Diluted-Fuel Combustion Issues in Burning Biogas Surrogates, ASME-JERT, (12 2009): . doi: 2010/01/07 10:47:38 2 TOTAL...blowout velocities. For each flow configuration, the coflow velocity is divided by the liftoff and blowout velocities to produce a dimensionless ratio...rate of the methane and the nitrogen were regulated with separate rotameters such that the amounts of methane and nitrogen issuing from the fuel pipe

  5. 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

  6. Orbital Cellulitis Following Orbital Blow-out Fracture.

    Science.gov (United States)

    Byeon, Je Yeon; Choi, Hwan Jun

    2017-10-01

    Orbital cellulitis and abscess have been described in the literature as complication that usually occur secondary to infection in the maxillary, ethmoidal, and frontal sinuses. If left untreated, it can lead to blindness, cavernous sinus thrombosis, meningitis, or cerebral abscess. Orbital fractures are a common sequela of blunt orbital trauma, but are only rarely associated with orbital cellulitis. So, the authors present rare orbital cellulitis after orbital blow-out fracture. A 55-year-old Asian complains of severe orbital swelling and pain on the left side. These symptoms had started 2 days earlier and worsened within the 24 hours before hospital admission resulting in visual disturbances such as diplopia and photophobia. Contrast-enhanced computed tomography scan showed considerable soft tissue swelling and abscess formation on the left side. Patient was subjected to surgical drainage under general anesthesia in the operation room. In this case, the postoperative period was uneventful and the rapid improvement of symptoms was remarkable. In conclusion, the abscess of the orbit is a surgical emergency in patients whose impairment of vision or ocular symptoms cannot be controlled with medical therapy using antibiotics. In our case, orbital cellulitis can occur after blunt orbital trauma without predisposing sinusitis. Early and prompt diagnosis and surgical drainage before severe loss of visual acuity rescue or recover the vision in case of orbital cellulitis.

  7. Contemporary management of carotid blowout syndrome utilizing endovascular techniques.

    Science.gov (United States)

    Manzoor, Nauman F; Rezaee, Rod P; Ray, Abhishek; Wick, Cameron C; Blackham, Kristine; Stepnick, David; Lavertu, Pierre; Zender, Chad A

    2017-02-01

    To illustrate complex interdisciplinary decision making and the utility of modern endovascular techniques in the management of patients with carotid blowout syndrome (CBS). Retrospective chart review. Patients treated with endovascular strategies and/or surgical modalities were included. Control of hemorrhage, neurological, and survival outcomes were studied. Between 2004 and 2014, 33 patients had 38 hemorrhagic events related to head and neck cancer that were managed with endovascular means. Of these, 23 were localized to the external carotid artery (ECA) branches and five localized to the ECA main trunk; nine were related to the common carotid artery (CCA) or internal carotid artery (ICA), and one event was related to the innominate artery. Seven events related to the CCA/ICA or innominate artery were managed with endovascular sacrifice, whereas three cases were managed with a flow-preserving approach (covered stent). Only one patient developed permanent hemiparesis. In two of the three cases where the flow-preserving approach was used, the covered stent eventually became exposed via the overlying soft tissue defect, and definitive management using carotid revascularization or resection was employed to prevent further hemorrhage. In cases of soft tissue necrosis, vascularized tissues were used to cover the great vessels as applicable. The use of modern endovascular approaches for management of acute CBS yields optimal results and should be employed in a coordinated manner by the head and neck surgeon and the neurointerventionalist. 4. Laryngoscope, 2016 127:383-390, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  8. Change of the orbital volume ratio in pure blow-out fractures depending on fracture location.

    Science.gov (United States)

    Oh, Sang Ah; Aum, Jae Ho; Kang, Dong Hee; Gu, Ja Hea

    2013-07-01

    The purposes of this study were to observe bony orbital volume (OV) changes in pure blow-out fractures according to fracture location using a facial computed tomographic scan and to investigate whether the OV measurements can be used as a quantitative value for the evaluation of the surgical results of the acute blow-out fracture.Forty-five patients with unilateral pure blow-out fracture were divided into 3 groups: inferior (group I), inferior medial (group IM), and medial (group M) orbital wall fracture. The OV and the orbital volume ratio (OVR) were prospectively measured before and 6 months after surgery with the use of 3-dimensional computed tomographic scans, and the Hertel scale was measured with a Hertel exothalmometer.The preoperative OVR increased to the greatest extent in group IM, and the mean preoperative OVR was 121.46. The mean preoperative OVR in group I was significantly higher than that of group M (P = 0.005). The OV and OVR revealed a statistically significant decrease after the surgery (P = 0.000). The Hertel scale improved from -1.04 mm before the surgery to -0.78 mm after the surgery, but no significant difference was observed (P = 0.051).The OVR was useful as a quantitative value to evaluate pure blow-out fractures, compared with that of the Hertel scale. Fracture location-associated OVR studies are needed to make volume guidelines of blow-out fracture surgery.

  9. 76 FR 49666 - Safety Zone; East Coast Drag Boat Bucksport Blowout Boat Race, Waccamaw River, Bucksport, SC

    Science.gov (United States)

    2011-08-11

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; East Coast Drag Boat Bucksport Blowout Boat... East Coast Drag Boat Bucksport Blowout in Bucksport, South Carolina. The East Coast Drag Boat Bucksport... September 18, 2011, the East Coast Drag Boat Association will host the East Coast Drag Boat Bucksport...

  10. Montara blowout - what went wrong? what are the lessons for industry and regulators?

    Energy Technology Data Exchange (ETDEWEB)

    Cutler, Jane [NOPSA Canada (Canada)

    2010-07-01

    PTTEP owns and operates the Montara development project which is situated in the Timor Sea. There are over 37 million barrels of oil reserves located about 650 km from Darwin and in 77m of water. This development is composed of 4 producing wells and 1 gas re-injection well; production was to be from an unmanned wellhead platform. Initial drilling on H1 started in January 2009 and a blowout occurred on this well on August 21st, 2009. The aim of this paper is to present the causes of this accident and the implications for the industry, governments and regulators, including Australian regulators. It was shown that the blowout resulted from a systemic failure by PTTEP to manage the integrity of the well. This incident put the offshore oil and gas industry in the spotlight. This paper presented the blowout which occurred in the Montara development project, its causes, and its consequences.

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

    Science.gov (United States)

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

    2012-01-01

    An extremely reliable remote control system for subsea blowout preventer stack is developed based on the off-the-shelf triple modular redundancy system. To meet a high reliability requirement, various redundancy techniques such as controller redundancy, bus redundancy and network redundancy are used to design the system hardware architecture. The control logic, human-machine interface graphical design and redundant databases are developed by using the off-the-shelf software. A series of experiments were performed in laboratory to test the subsea blowout preventer stack control system. The results showed that the tested subsea blowout preventer functions could be executed successfully. For the faults of programmable logic controllers, discrete input groups and analog input groups, the control system could give correct alarms in the human-machine interface. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

  12. 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.

  13. A review of seafood safety after the deepwater horizon blowout.

    Science.gov (United States)

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

    2011-08-01

    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. We aimed to assess this protocol based on comparisons with previous oil spills, published testing results, and current knowledge regarding chemicals released during the DH oil spill. We performed a comprehensive review of relevant scientific journal articles and government documents concerning seafood contamination and oil spills and consulted with academic and government experts. Protocols to evaluate seafood safety before reopening fisheries have relied on risk assessment of health impacts from polycyclic aromatic hydrocarbon (PAH) exposures, but metal contamination may also be a concern. Assumptions used to determine levels of concern (LOCs) after oil spills have not been consistent across risk assessments performed after oil spills. Chemical testing results after the DH oil spill suggest PAH levels are at or below levels reported after previous oil spills, and well below LOCs, even when more conservative parameters are used to estimate risk. We recommend use of a range of plausible risk parameters to set bounds around LOCs, comparisons of post-spill measurements with baseline levels, and the development and implementation of long-term monitoring strategies for metals as well as PAHs and dispersant components. In addition, the methods, results, and uncertainties associated with estimating seafood safety after oil spills should be communicated in a transparent and timely manner, and stakeholders should be actively involved in developing a long-term monitoring strategy.

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

    KAUST Repository

    Wang, Qiang

    2016-12-09

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

  15. The Hydraulic Mechanism in the Orbital Blowout Fracture Because of a High-Pressure Air Gun Injury.

    Science.gov (United States)

    Kang, Seok Joo; Chung, Eui Han

    2015-10-01

    There are 2 predominant mechanisms that are used to explain the pathogenesis of orbital blowout fracture; these include hydraulic and buckling mechanisms. Still, however, its pathophysiology remains uncertain. To date, studies in this series have been conducted using dry skulls, cadavers, or animals. But few clinical studies have been conducted to examine whether the hydraulic mechanism is involved in the occurrence of pure orbital blowout fracture. The authors experienced a case of a 52-year-old man who had a pure medial blowout fracture after sustaining an eye injury because of a high-pressure air gun. Our case suggests that surgeons should be aware of the possibility that the hydraulic mechanism might be involved in the blowout fracture in patients presenting with complications, such as limitation of eye movement, diplopia, and enophthalmos.

  16. Numerical simulation of water and sand blowouts when penetrating through shallow water flow formations in deep water drilling

    Science.gov (United States)

    Ren, Shaoran; Liu, Yanmin; Gong, Zhiwu; Yuan, Yujie; Yu, Lu; Wang, Yanyong; Xu, Yan; Deng, Junyu

    2018-02-01

    In this study, we applied a two-phase flow model to simulate water and sand blowout processes when penetrating shallow water flow (SWF) formations during deepwater drilling. We define `sand' as a pseudo-component with high density and viscosity, which can begin to flow with water when a critical pressure difference is attained. We calculated the water and sand blowout rates and analyzed the influencing factors from them, including overpressure of the SWF formation, as well as its zone size, porosity and permeability, and drilling speed (penetration rate). The obtained data can be used for the quantitative assessment of the potential severity of SWF hazards. The results indicate that overpressure of the SWF formation and its zone size have significant effects on SWF blowout. A 10% increase in the SWF formation overpressure can result in a more than 90% increase in the cumulative water blowout and a 150% increase in the sand blowout when a typical SWF sediment is drilled. Along with the conventional methods of well flow and pressure control, chemical plugging, and the application of multi-layer casing, water and sand blowouts can be effectively reduced by increasing the penetration rate. As such, increasing the penetration rate can be a useful measure for controlling SWF hazards during deepwater drilling.

  17. The use of pulsed high-speed liquid jet for putting out gas blow-out

    Directory of Open Access Journals (Sweden)

    A Semko

    2016-10-01

    Full Text Available The experimental analysis of putting out a gas blow-out with the help of pulse liquid flow with high velocity, which generates by powder pulse water-cannon are carried out. The flow velocity resides in range from 300 to 600 m/s in experiments depends on charge energy. Velocity of the flow head right near the gas flame determined with the help of laser contactless measuring instrument of velocity. Photography of flow was carried out. According to the preliminary test results the hydrodynamic parameters of powder pulse water-cannon for obtaining liquid flow with depend velocity are calculated. It is shown, that around the liquid flow of high velocity in air produced fine water spray with high velocity in large cross section area that effective knock down the gas blow-out at the distance 5-20 m from installation.

  18. Microbiological investigations after the ``Bravo'' blowout (Ekofisk oil field, North Sea)

    Science.gov (United States)

    Gunkel, W.; Pedersen, S.; Dundas, I.; Eimhjellen, K.

    1985-03-01

    Following the accident in 1977 at an offshore oil producing platform in the Ekofisk oil field (North Sea) an estimated amount of 13000 15000 tons of oil polluted the sea. Microbiological investigations were conducted one to five weeks after the blowout and compared with data collected in the same area during the years before. Bacterial numbers in the water were fairly low. In the floating oil particles, however, extremely high values were obtained (2 × 1011 heterotrophic bacteria 1-1 and 5 × 1010 oil degrading bacteria 1-1). The data on oxygen consumption gave markedly different results indicating that the oil degradation potential of the water seemed to vary widely from one station to another. The greatest increase in oxygen consumption (following the addition of oil to the bottles) occurred in samples taken at the station where oil particles from the blowout were observed floating on the surface. This indicates a higher oil degradation potential.

  19. Clinical characteristics and treatment of blow-out fracture accompanied by canalicular laceration.

    Science.gov (United States)

    Lee, Hwa; Ahn, Jaemoon; Lee, Tae Eun; Lee, Jong Mi; Shin, Hyungho; Chi, Mijung; Park, Minsoo; Baek, Sehyun

    2012-09-01

    Blow-out fracture and canalicular laceration can occur simultaneously as a result of the same trauma. Despite its importance, little research has been conducted to identify clinical characteristics or surgical techniques for repair of a blow-out fracture accompanied by canalicular laceration. The aim of this study was to evaluate the clinical characteristics, the surgical approach, and the outcomes. Thirty-four eyes of 34 patients who underwent simultaneous repair of canalicular laceration using silicone tube intubation and reconstruction of blow-out fracture were included. Medical records were retrospectively reviewed for patient demographics, nature of injury, affected canaliculus, location, and severity of blow-out fracture, associated facial bone fracture, ophthalmic diagnosis, length of follow-up period, and surgical outcome. Mean patient age was 40.0 years (range, 17-71 y). The mean follow-up was 7.3 months. Fist to the orbital area (10 patients, 29.4%) was the most common cause. There were 24 lower canalicular lacerations (70.6%), 6 upper canalicular lacerations (17.6%), and 4 upper and lower canalicular lacerations (11.8%). Isolated medial wall fractures were most common (area A4: 20/34, 58.8%). Fractures involving both the floor and medial wall and maxillo-ethmoidal strut (areas A1, A2, A3, and A4) were the second most common (6/34, 17.6%), and floor and medial wall with intact strut (areas A1, A2, and A4) were injured in 6 patients (17.6%). Pure inferior wall fractures were least frequent (areas A1 and A2: 2/34, 5.9%). The severity of the fracture was severe in most patients except for 1 linear fracture with tissue entrapment and 1 moderate medial wall fracture (32/34, 94.1%). There was lid laceration in 20 patients (58.8%). Nasal bone fracture (5/34, 14.7%) was the most common facial bone fracture. Tubes were removed at a mean of 3.3 months (range, 3-4 mo). In total, 31 patients (91.2%) achieved complete success in canalicular laceration and blow-out

  20. Application on forced traction test in surgeries for orbital blowout fracture

    Directory of Open Access Journals (Sweden)

    Bao-Hong Han

    2014-05-01

    Full Text Available AIM: To discuss the application of forced traction test in surgeries for orbital blowout fracture.METHODS: The clinical data of 28 patients with reconstructive surgeries for orbital fracture were retrospectively analyzed. All patients were treated with forced traction test before/in/after operation. The eyeball movement and diplopia were examined and recorded pre-operation, 3 and 6mo after operation, respectively.RESULTS: Diplopia was improved in all 28 cases with forced traction test. There was significant difference between preoperative and post-operative diplopia at 3 and 6mo(PCONCLUSION: Forced traction test not only have a certain clinical significance in diagnosis of orbital blowout fracture, it is also an effective method in improving diplopia before/in/after operation.

  1. Blow-Out Velocities of Solutions of Hydrocarbons and Boron Hydride - Hydrocarbon Reaction Products in a 1 7/8-Inch-Diameter Combustor

    Science.gov (United States)

    Morris, James F.; Lord, Albert M.

    1957-01-01

    Blow-out velocities were determined for JP-4 solutions containing: (1) 10 % ethylene - decaborane reaction product, (2) 10% and 20% acetylene - diborane reaction product, and (3) 5.5%, 15.7%, and 30.7% methylacetylene - diborane reaction product. These were compared with blow-out velocities for JP-4, propylene oxide, and neohexane and previously reported data for JP-4 solutions of pentaborane. For those reaction products investigated, the blow-out velocities at a fixed equivalence ratio were higher for those materials containing higher boron concentrations; that is, blow-out velocity increased in the following order: (1) methylacetylene - diborane, (2) acetylene - diborane, and (3) ethylene - decaborane reaction products.

  2. Fine wakefield structure in the blowout regime of plasma wakefield accelerators

    Directory of Open Access Journals (Sweden)

    K. V. Lotov

    2003-06-01

    Full Text Available For simulations of plasma wakefield acceleration (PWFA and similar problems, we developed two-dimensional fully electromagnetic fully relativistic hybrid code LCODE. The code is very fast due to explicit use of several simplifying assumptions (quasistatic approximation, ultrarelativistic beam, and the symmetry. With LCODE, we make high-resolution simulations of the blowout regime of PWFA and study the temperature effect on the amplitude of the accelerating field spike.

  3. A Micro Coronal Mass Ejection Associated Blowout Extreme-ultraviolet Jet

    Science.gov (United States)

    Hong, Junchao; Jiang, Yunchun; Zheng, Ruisheng; Yang, Jiayan; Bi, Yi; Yang, Bo

    2011-09-01

    The so-called mini coronal mass ejections (CMEs) were recently identified as small-scale eruptive events showing the same on-disk characteristics as large-scale CMEs, and Moore et al. further found that one-third of polar X-ray jets are the so-called blowout jets, in which the jet-base magnetic arch, often carrying a filament, undergoes a miniature version of the blowout eruptions that produce major CMEs. By means of the two viewpoint observations from the Solar Dynamics Observatory (SDO) and the Ahead of Solar Terrestrial Relations Observatory (STEREO A), in this Letter, we present the first observations that a blowout jet from the eruption of an EUV mini-filament channel in the quiet Sun was indeed associated with a real micro-CME. Captured by the on-disk SDO observations, the whole life of the mini-filament channel, from the formation to eruption, was associated with convergences and cancellations of opposite-polarity magnetic flux in the photosphere, and its eruption was accompanied by a small flare-like brightening, a small corona dimming, and posteruptive loops. The near-limb counterpart of the eruption observed by STEREO A, however, showed up as a small EUV jet followed by a white-light jet. These observations not only confirm the previous results that mini-filaments have characteristics common to large-scale ones, but also give clear evidences that blowout jets can result from the eruptions of mini-filaments and are associated with mini-CME.

  4. Breaking primary seed dormancy in Gibbens' beardtongue (Penstemon gibbensii) and blowout penstemon (Penstemon haydenii)

    Science.gov (United States)

    Kassie L. Tilini; Susan E. Meyer; Phil S. Allen

    2016-01-01

    This study established that chilling removes primary seed dormancy in 2 rare penstemons of the western US, Gibbens’ beardtongue (Penstemon gibbensii Dorn [Scrophulariaceae]) and blowout penstemon (Penstemon haydenii S. Watson). Wild-harvested seeds were subjected either to moist chilling at 2 to 4 °C (36-39 °F) for 0, 4, 8, 12, and 16 wk or to approximately 2 y of dry...

  5. Diplopia and ocular motility in orbital blow-out fractures: 10-year retrospective study.

    Science.gov (United States)

    Alhamdani, Faaiz; Durham, Justin; Greenwood, Mark; Corbett, Ian

    2015-09-01

    To investigate diplopia (binocular single vision [BSV] test) and ocular motility (uniocular field of fixation [UFOF] test) characteristics in blow-out fractures of the orbit and their value in fracture management. Patients with isolated blow-out fractures treated from 2000 to 2010 were included. BSV scores were stratified into three categories: low BSV category (0-60); moderate BSV category (61-80), and high BSV category (81-100). UFOF scores were also divided into three categories: low score (60-240), moderate score (241-270), and high score (271-365) categories. A total of 183 patients (106 surgically and 77 conservatively managed) met the inclusion criteria. There was no significant improvement in BSV postoperatively in surgically managed patients with preoperatively high BSV, whereas there was significant improvement (p blow-out fracture cases with BSV score >80% for correction of diplopia alone. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  6. Antiadhesive effect of mixed solution of sodium hyaluronate and sodium carboxymethylcellulose after blow-out fracture repair.

    Science.gov (United States)

    Lee, Jong Mi; Baek, Sehyun

    2012-11-01

    Treatment of blow-out fractures is aimed at the prevention of permanent diplopia and cosmetically unacceptable enophthalmos. Porous polyethylene sheets are one of the most common alloplastic implants for blow-out fracture repair. Because adhesion between the porous polyethylene and the orbital soft tissue can result in restrictions of ocular motility, prevention of postoperative adhesion is important in the reconstruction of blow-out fractures. The purpose of this study was to find out the effect of the mixed solution of sodium hyaluronate and sodium carboxymethylcellulose (HACMC) on postoperative adhesion in blow-out fracture repair in an animal model.Twenty-four New Zealand white rabbits were used. An 8-mm defect was made in the maxillary sinuses including the bone and mucosa. A 10-mm porous polyethylene sheet (Medpor; Porex Surgical Inc., Newnan, GA) was inserted in to the defect. The rabbits were divided into a control group and a HACMC group. In the HACMC group, HACMC solution was instilled onto the surface of the implant and then the implant was inserted. The implants were harvested at 1, 2, 4, and 8 weeks after surgery (3 implants each period). Hematoxylin and eosin, Masson trichrome, and CD31 (platelet endothelial cell adhesion molecule-1) stains were performed for evaluation of inflammation, fibrosis, and vascularization.Inflammation appeared less severe in the HACMC group, but the difference between the 2 groups was not statistically significant. The degree of fibrosis was more severe in the control group. There were significant differences in the degree of fibrosis between the 2 groups 4 and 8 weeks after surgery (P = 0.046). The amount of vascularization was similar in both groups.The HACMC solution seemed to be effective for reducing postoperative adhesion in reconstruction of blow-out fractures in a rabbit model. Our results suggest that the application of HACMC solution could be an effective adjunct for the repair of trap-door fractures or revision

  7. Orbital Blowout Fracture with Complete Dislocation of the Globe into the Maxillary Sinus.

    Science.gov (United States)

    Wang, Joy Mh; Fries, Fabian N; Hendrix, Philipp; Brinker, Titus; Loukas, Marios; Tubbs, R Shane

    2017-09-29

    This rare case report describes the diagnosis and treatment of an isolated left-sided orbital floor fracture with a complete dislocation of the globe into the maxillary sinus and briefly discusses the indications of surgery and recovery for orbital floor fractures in general. Complete herniation of the globe through an orbital blow-out fracture is uncommon. However, the current case illustrates that such an occurrence should be in the differential diagnosis and should be considered, especially following high speed/impact injuries involving a foreign object. In these rare cases, surgical intervention is required.

  8. Fatal carotid blowout syndrome after BNCT for head and neck cancers

    International Nuclear Information System (INIS)

    Aihara, T.; Hiratsuka, J.; Ishikawa, H.; Kumada, H.; Ohnishi, K.; Kamitani, N.; Suzuki, M.; Sakurai, H.; Harada, T.

    2015-01-01

    Boron neutron capture therapy (BNCT) is high linear energy transfer (LET) radiation and tumor-selective radiation that does not cause serious damage to the surrounding normal tissues. BNCT might be effective and safe in patients with inoperable, locally advanced head and neck cancers, even those that recur at previously irradiated sites. However, carotid blowout syndrome (CBS) is a lethal complication resulting from malignant invasion of the carotid artery (CA); thus, the risk of CBS should be carefully assessed in patients with risk factors for CBS after BNCT. Thirty-three patients in our institution who underwent BNCT were analyzed. Two patients developed CBS and experienced widespread skin invasion and recurrence close to the carotid artery after irradiation. Careful attention should be paid to the occurrence of CBS if the tumor is located adjacent to the carotid artery. The presence of skin invasion from recurrent lesions after irradiation is an ominous sign of CBS onset and lethal consequences. - Highlights: • This study is fatal carotid blowout syndrome after BNCT for head and neck cancers. • Thirty-three patients in our institution who underwent BNCT were analyzed. • Two patients (2/33) developed CBS. • The presence of skin invasion from recurrent lesions after irradiation is an ominous sign of CBS. • We must be aware of these signs to perform BNCT safely.

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

    International Nuclear Information System (INIS)

    Brandt, C.; Becker, J.; Dauble, D.

    1995-01-01

    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

  10. Blowout Surge due to Interaction between a Solar Filament and Coronal Loops

    Energy Technology Data Exchange (ETDEWEB)

    Li, Haidong; Jiang, Yunchun; Yang, Jiayan; Yang, Bo; Xu, Zhe; Bi, Yi; Hong, Junchao; Chen, Hechao [Yunnan Observatories, Chinese Academy of Sciences, 396 Yangfangwang, Guandu District, Kunming, 650216 (China); Qu, Zhining, E-mail: lhd@ynao.ac.cn [Department of Physics, School of Science, Sichuan University of Science and Engineering, Zigong 643000 (China)

    2017-06-20

    We present an observation of the interaction between a filament and the outer spine-like loops that produces a blowout surge within one footpoint of large-scale coronal loops on 2015 February 6. Based the observation of the AIA 304 and 94 Å, the activated filament is initially embedded below a dome of a fan-spine configuration. Due to the ascending motion, the erupting filament reconnects with the outer spine-like field. We note that the material in the filament blows out along the outer spine-like field to form the surge with a wider spire, and a two-ribbon flare appears at the site of the filament eruption. In this process, small bright blobs appear at the interaction region and stream up along the outer spine-like field and down along the eastern fan-like field. As a result, a leg of the filament becomes radial and the material in it erupts, while another leg forms the new closed loops. Our results confirm that the successive reconnection occurring between the erupting filament and the coronal loops may lead to a strong thermal/magnetic pressure imbalance, resulting in a blowout surge.

  11. On a Solar Blowout Jet: Driving Mechanism and the Formation of Cool and Hot Components

    Science.gov (United States)

    Shen, Yuandeng; Liu, Ying D.; Su, Jiangtao; Qu, Zhining; Tian, Zhanjun

    2017-12-01

    We present observations of a blowout jet that experienced two distinct ejection stages. The first stage started from the emergence of a small positive magnetic polarity, which was cancelled by the nearby negative magnetic field and caused the rising of a mini-filament and its confining loops. This further resulted in a small jet due to the magnetic reconnection between the rising confining loops and the overlying open field. The second ejection stage was mainly due to successive removal of the confining field by reconnection: the filament erupted, and the erupting cool filament material directly combined with the hot jet that originated form the reconnection region and therefore formed the cool and hot components of the blowout jet. During the two ejection stages, cool Hα jets are also observed cospatial with their coronal counterparts, but their appearance times are earlier by a few minutes than those of the hot coronal jets. The hot coronal jets are therefor possibly caused by the heating of the cool Hα jets or the rising of the reconnection height from the chromosphere to the corona. The scenario that magnetic reconnection occurred between the confining loops and the overlying open loops is supported by many observational facts, including the bright patches on both sides of the mini-filament, hot plasma blobs along the jet body, and periodic metric radio type III bursts at the very beginnings of the two stages. The evolution and characteristics of these features show the detailed nonlinear process in magnetic reconnection.

  12. Flow and sediment transport dynamics in a slot and cauldron blowout and over a foredune, Mason Bay, Stewart Island (Rakiura), NZ

    Science.gov (United States)

    Hesp, Patrick A.; Hilton, Michael; Konlecher, Teresa

    2017-10-01

    This study is the first to simultaneously compare flow and sediment transport through a blowout and over an adjacent foredune, and the first study of flow within a highly sinuous, slot and cauldron blowout. Flow across the foredune transect is similar to that observed in other studies and is primarily modulated by across-dune vegetation density differences. Flow within the blowout is highly complex and exhibits pronounced accelerations and jet flow. It is characterised by marked helicoidal coherent vortices in the mid-regions, and topographically vertically forced flow out of the cauldron portion of the blowout. Instantaneous sediment transport within the blowout is significant compared to transport onto and/or over the adjacent foredune stoss slope and ridge, with the blowout providing a conduit for suspended sediment to reach the downwind foredune upper stoss slope and crest. Medium term (4 months) aeolian sedimentation data indicates sand is accumulating in the blowout entrance while erosion is taking place throughout the majority of the slot, and deposition is occurring downwind of the cauldron on the foredune ridge. The adjacent lower stoss slope of the foredune is accreting while the upper stoss slope is slightly erosional. Longer term (16 months) pot trap data shows that the majority of foredune upper stoss slope and crest accretion occurs via suspended sediment delivery from the blowout, whereas the majority of the suspended sediment arriving to the well-vegetated foredune stoss slope is deposited on the mid-stoss slope. The results of this study indicate one mechanism of how marked alongshore foredune morphological variability evolves due to the role of blowouts in topographically accelerating flow, and delivering significant aeolian sediment downwind to relatively discrete sections of the foredune.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-09-01

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

  14. 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)

    Klavano, G.G.; Christian, R.G.

    1992-01-01

    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

  15. 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.

  16. The predictive factors of diplopia and extraocular movement limitations in isolated pure blow-out fracture.

    Science.gov (United States)

    Kasaee, Abolfazl; Mirmohammadsadeghi, Arash; Kazemnezhad, Fatemeh; Eshraghi, Bahram; Akbari, Mohammad Reza

    2017-03-01

    To evaluate the predictive factors for development of diplopia and extraocular muscle movement (EOM) limitations in the patients with isolated pure blow-out fracture. One hundred thirty-two patients with isolated pure blow-out fracture were included. The diagnosis was done with computed tomography scan. Possible predictive factors were analyzed with logistic regression. The cases that underwent surgery were assigned in the surgical group, and other cases were assigned in the non-surgical group. Receiver operating characteristic (ROC) curve analysis was used in the surgical group to evaluate the power of time interval from trauma to the surgery to predict persistence of 6 months postoperative diplopia and EOM limitation. At the first visit, 45 of 60 cases (75%) in the surgical group and 15 of 72 cases (20.8%) in the nonsurgical group had diplopia. After 6 months follow-up, 7 cases (11.7%) in the surgical group and 1 case (1.4%) in the nonsurgical group had persistent diplopia. Type of fracture was significantly associated with first visit diplopia (P = 0.01) and EOM limitations (P = 0.06). In the surgical group, type of fracture (P = 0.02 for both) and time interval from trauma to the surgery (P = 0.006 and 0.004, respectively) were significantly associated with 1 month diplopia and EOM limitations. Only time interval from trauma to the surgery (P = 0.04) was significantly associated with 3 months EOM limitation. In the ROC curve analysis, if the surgery was done before 4.5 (sensitivity = 87.5% and specificity = 61.3%) and 7.5 (sensitivity = 87.5% and specificity = 66.9%) days, risk of 6 months postoperative diplopia and EOM limitation was reduced, respectively. In the early postoperative period, a higher rate of diplopia was observed in the patients with combined inferior and medial wall fractures and longer time intervals from trauma to the surgery. The best time for blow-out fracture surgery was within 4.5 days after the trauma.

  17. Short-range wakefields generated in the blowout regime of plasma-wakefield acceleration

    Science.gov (United States)

    Stupakov, G.

    2018-04-01

    In the past, calculation of wakefields generated by an electron bunch propagating in a plasma has been carried out in linear approximation, where the plasma perturbation can be assumed small and plasma equations of motion linearized. This approximation breaks down in the blowout regime where a high-density electron driver expels plasma electrons from its path and creates a cavity void of electrons in its wake. In this paper, we develop a technique that allows us to calculate short-range longitudinal and transverse wakes generated by a witness bunch being accelerated inside the cavity. Our results can be used for studies of the beam loading and the hosing instability of the witness bunch in plasma-wakefield and laser-wakefield acceleration.

  18. Longitudinal phase space characterization of the blow-out regime of rf photoinjector operation

    Directory of Open Access Journals (Sweden)

    J. T. Moody

    2009-07-01

    Full Text Available Using an experimental scheme based on a vertically deflecting rf deflector and a horizontally dispersing dipole, we characterize the longitudinal phase space of the beam in the blow-out regime at the UCLA Pegasus rf photoinjector. Because of the achievement of unprecedented resolution both in time (50 fs and energy (1.0 keV, we are able to demonstrate some important properties of the beams created in this regime such as extremely low longitudinal emittance, large temporal energy chirp, and the degrading effects of the cathode image charge in the longitudinal phase space which eventually leads to poorer beam quality. All of these results have been found in good agreement with simulations.

  19. Ion response to relativistic electron bunches in the blowout regime of laser-plasma accelerators.

    Science.gov (United States)

    Popov, K I; Rozmus, W; Bychenkov, V Yu; Naseri, N; Capjack, C E; Brantov, A V

    2010-11-05

    The ion response to relativistic electron bunches in the so called bubble or blowout regime of a laser-plasma accelerator is discussed. In response to the strong fields of the accelerated electrons the ions form a central filament along the laser axis that can be compressed to densities 2 orders of magnitude higher than the initial particle density. A theory of the filament formation and a model of ion self-compression are proposed. It is also shown that in the case of a sharp rear plasma-vacuum interface the ions can be accelerated by a combination of three basic mechanisms. The long time ion evolution that results from the strong electrostatic fields of an electron bunch provides a unique diagnostic of laser-plasma accelerators.

  20. Role of Negative Orbit Vector in Orbital Blow-Out Fractures.

    Science.gov (United States)

    Choi, Soo Youn; Lee, Hwa; Baek, Sehyun

    2017-11-01

    Negative orbit vector is defined as the most anterior globe portion protrudes past the malar eminence. The aim of the study was to evaluate the relationship between negative orbit vector and blow-out fracture location analyzing the distance between the anterior corneal surface and orbital bone with facial soft tissue in medial and orbital floor blow out fractures using orbital computed tomography (CT). Seventy-seven patients diagnosed with blow-out fractures involving the medial or orbital floor were included. Distances from the anterior cornea to lower lid fat, inferior orbital wall, inferior orbital rim, and anterior cheek mass were measured using orbital CT scans. The proportion of negative orbit vector and measured distanced were compared between medial wall fracture and orbital floor fracture. Medical records including age, sex, concomitant ophthalmic diagnosis, and nature of injury were retrospectively reviewed. Forty-three eyes from 43 patients diagnosed with medial wall fracture and 34 eyes from 34 patients diagnosed with orbital floor fracture were included. There was no significant difference in the distance from the anterior cornea to lower lid fat (P = 0.574), inferior orbital wall (P = 0.494), or orbital rim (P = 0.685). The distance from anterior cornea to anterior cheek mass was significantly different in medial wall fracture (-0.19 ± 3.49 mm) compared with orbital floor fracture (-1.69 ± 3.70 mm), P = 0.05. Negative orbit vector was significantly higher in orbital floor fracture patients (24 among 34 patients, 70.6%) compared with those with medial wall fractures (19 among 43 patients, 44.2%) (P = 0.04). Patients presenting with a negative orbit vector relationship when the most anterior portion of globe protruded past the anterior cheek mass and malar eminence were more likely to develop orbital floor fracture than medial wall fracture.

  1. A novel integrated approach for path following and directional stability control of road vehicles after a tire blow-out

    Science.gov (United States)

    Wang, Fei; Chen, Hong; Guo, Konghui; Cao, Dongpu

    2017-09-01

    The path following and directional stability are two crucial problems when a road vehicle experiences a tire blow-out or sudden tire failure. Considering the requirement of rapid road vehicle motion control during a tire blow-out, this article proposes a novel linearized decoupling control procedure with three design steps for a class of second order multi-input-multi-output non-affine system. The evaluating indicators for controller performance are presented and a performance related control parameter distribution map is obtained based on the stochastic algorithm which is an innovation for non-blind parameter adjustment in engineering implementation. The analysis on the robustness of the proposed integrated controller is also performed. The simulation studies for a range of driving conditions are conducted, to demonstrate the effectiveness of the proposed controller.

  2. Impact of an historic underground gas well blowout on the current methane chemistry in a shallow groundwater system.

    Science.gov (United States)

    Schout, Gilian; Hartog, Niels; Hassanizadeh, S Majid; Griffioen, Jasper

    2018-01-09

    Blowouts present a small but genuine risk when drilling into the deep subsurface and can have an immediate and significant impact on the surrounding environment. Nevertheless, studies that document their long-term impact are scarce. In 1965, a catastrophic underground blowout occurred during the drilling of a gas well in The Netherlands, which led to the uncontrolled release of large amounts of natural gas from the reservoir to the surface. In this study, the remaining impact on methane chemistry in the overlying aquifers was investigated. Methane concentrations higher than 10 mg/L ( n = 12) were all found to have δ 13 C-CH 4 values larger than -30‰, typical of a thermogenic origin. Both δ 13 C-CH 4 and δD-CH 4 correspond to the isotopic composition of the gas reservoir. Based on analysis of local groundwater flow conditions, this methane is not a remnant but most likely the result of ongoing leakage from the reservoir as a result of the blowout. Progressive enrichment of both δ 13 C-CH 4 and δD-CH 4 is observed with increasing distance and decreasing methane concentrations. The calculated isotopic fractionation factors of ε C = 3 and ε D = 54 suggest anaerobic methane oxidation is partly responsible for the observed decrease in concentrations. Elevated dissolved iron and manganese concentrations at the fringe of the methane plume show that oxidation is primarily mediated by the reduction of iron and manganese oxides. Combined, the data reveal the long-term impact that underground gas well blowouts may have on groundwater chemistry, as well as the important role of anaerobic oxidation in controlling the fate of dissolved methane. Copyright © 2018 the Author(s). Published by PNAS.

  3. MINIFILAMENT ERUPTION AS THE SOURCE OF A BLOWOUT JET, C-CLASS FLARE, AND TYPE-III RADIO BURST

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Junchao; Jiang, Yunchun; Yang, Jiayan; Li, Haidong; Xu, Zhe, E-mail: hjcsolar@ynao.ac.cn [Yunnan Observatories, Chinese Academy of Sciences, 396 Yangfangwang, Guandu District, Kunming, 650216 (China); Center for Astronomical Mega-Science, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing, 100012 (China)

    2017-01-20

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

  4. 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)

    Harris, B.

    1992-01-01

    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

  5. Outcomes of Orbital Blow-Out Fracture Repair Performed Beyond 6 Weeks After Injury.

    Science.gov (United States)

    Scawn, Richard L; Lim, Lee Hooi; Whipple, Katherine M; Dolmetsch, Angela; Priel, Ayelet; Korn, Bobby; Kikkawa, Don O

    2016-01-01

    Blow-out fractures cause expansion of the bony orbital walls and prolapse of orbital contents in the sinuses. This can result in diplopia, enophthalmos, and hypoglobus. Early surgical repair has been previously recommended, however, recent reports show that delayed surgery can also be effective. In this study, the clinical and functional outcome of patients with delayed presentation and blow-out fracture repair beyond 6 weeks after injury are described. This is a noncomparative retrospective study. Medical records of adult patients with late orbital floor fracture repair performed by 4 surgeons from April 2008 to January 2014 at 3 tertiary referral centers were reviewed. All repairs were performed more than 6 weeks from the time of injury. Patients with prior orbital fracture repair surgery were excluded. Twenty patients were included in the study. The duration from time of injury to surgery ranged from 7 weeks to 21 years with a mean of 19 months. Follow up ranged from 6 weeks to 56 months (mean 8 months). Mean age was 48 years (range, 25-80). Male to female ratio was 11:9. Surgery was performed on 10 right eyes and 10 left eyes. CT imaging demonstrated 10 patients had isolated floor fractures, while the remaining 10 patients had combined floor and medial wall fractures. Four patients also had associated facial fractures that did not require surgery. Indications for surgery included enophthalmos of 2 mm or more (18 of 20) and/or significant diplopia within 30° of primary gaze (6 of 20). Mean pre- and postoperative enophthalmos was 2.4 ± 0.9 mm and 0.3 ± 0.2 mm, respectively, corresponding to a mean reduction in enophthalmos of 2.1 ± 1.2 mm (range, 1-5 mm). Four of 7 patients with hypoglobus ranging from 1.5 mm to 8 mm preoperatively had complete resolution postoperatively, the remaining 3 patients showed reduced hypoglobus. Of the 12 patients that had diplopia preoperatively in any position of gaze, 6 patients had complete resolution

  6. 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

  7. Environmental legacy of an underground gas well blowout: long-term effects of gas and brine leakage on groundwater quality

    Science.gov (United States)

    Schout, Gilian; Hartog, Niels; Majid Hassanizadeh, S.; Griffioen, Jasper

    2017-04-01

    In 1965, a catastrophic underground blowout occurred during the drilling of a gas well in the village of Sleen, the Netherlands. The blowout led to the uncontrolled release of large amounts of natural gas and saline groundwater. Now, 50 years later, a number of nearby groundwater monitoring have been sampled to study the long term effects of this event on the groundwater composition of the overlying freshwater aquifers. The findings are used as an analogue for studying the potential adverse effects of hydraulic fracturing on groundwater quality. In total, 27 samples were taken and analysed for dissolved gas molecular and isotopic composition, major ion chemistry, water isotopes and stable chlorine isotope ratios. The resulting data show that concentrations of dissolved methane are still strongly elevated compared to background samples in a plume downstream of the blowout location. Isotopic data reveals the thermogenic nature of this plume; all samples with methane concentrations greater than 10 mg/l (n=12) had δC-CH4 values greater than -30‰ (VPDB), characteristic of thermogenic methane. The maximum distance at which thermogenic methane is observed is at approximately 500 meter downstream of the centre of the blowout. The progressive enrichment of both δ13C-CH4 and δ2D-CH4, that is observed with distance from the well and decreasing methane concentrations, presents strong evidence for the role of anaerobic methane oxidation (AOM) in limiting the spread of the dissolved methane plume. Low sulphate and increased Fe(II) and Mn(II) concentrations indeed suggest that multiple AOM pathways are involved in the natural attenuation of the dissolved methane plume. Chlorine concentrations were only elevated in a subset of wells in close proximity to the blowout location, indicating that the present-day effects of brine migration are minimal. Nevertheless, elevated Na/Cl ratio's in multiple wells reveal that freshening of the aquifer is still on-going. In summary, this

  8. Quantitative Risk Assessment (QRA) for an Underground Blowout Scenario in the Gulf of Mexico (GoM) Well

    Science.gov (United States)

    Tyagi, M.; Zulqarnain, M.

    2017-12-01

    Offshore oil and gas exploration and production operations, involve the use of some of the cutting edge and challenging technologies of the modern time. These technological complex operations involves the risk of major accidents as well, which have been demonstrated by disasters such as the explosion and fire on the UK production platform piper alpha, the Canadian semi-submersible drilling rig Ocean Ranger and the explosion and capsizing of Deepwater horizon rig in the Gulf of Mexico. By conducting Quantitative Risk Assessment (QRA), safety of various operations as well as their associated risks and significance during the entire life phase of an offshore project can be quantitatively estimated. In an underground blowout, the uncontrolled formation fluids from higher pressure formation may charge up shallower overlying low pressure formations or may migrate to sea floor. Consequences of such underground blowouts range from no visible damage at the surface to the complete loss of well, loss of drilling rig, seafloor subsidence or hydrocarbons discharged to the environment. These blowouts might go unnoticed until the over pressured sands, which are the result of charging from higher pressure reservoir due to an underground blowout. Further, engineering formulas used to estimate the fault permeability and thickness are very simple in nature and may add to uncertainty in the estimated parameters. In this study the potential of a deepwater underground blowout are assessed during drilling life phase of a well in Popeye-Genesis field reservoir in the Gulf of Mexico to estimate the time taken to charge a shallower zone to its leak-off test (LOT) value. Parametric simulation results for selected field case show that for relatively high permeability (k = 40mD) fault connecting a deep over-pressured zone to a shallower low-pressure zone of similar reservoir volumes, the time to recharge the shallower zone up to its threshold LOT value is about 135 years. If the ratio of the

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-01-15

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

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

    Science.gov (United States)

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

    2013-07-01

    This article proposes a methodology for the application of Bayesian networks in conducting quantitative risk assessment of operations in offshore oil and gas industry. The method involves translating a flow chart of operations into the Bayesian network directly. The proposed methodology consists of five steps. First, the flow chart is translated into a Bayesian network. Second, the influencing factors of the network nodes are classified. Third, the Bayesian network for each factor is established. Fourth, the entire Bayesian network model is established. Lastly, the Bayesian network model is analyzed. Subsequently, five categories of influencing factors, namely, human, hardware, software, mechanical, and hydraulic, are modeled and then added to the main Bayesian network. The methodology is demonstrated through the evaluation of a case study that shows the probability of failure on demand in closing subsea ram blowout preventer operations. The results show that mechanical and hydraulic factors have the most important effects on operation safety. Software and hardware factors have almost no influence, whereas human factors are in between. The results of the sensitivity analysis agree with the findings of the quantitative analysis. The three-axiom-based analysis partially validates the correctness and rationality of the proposed Bayesian network model. © 2012 Society for Risk Analysis.

  11. Research on Performance of H2 Rich Blowout Limit in Bluff-Body Burner

    Directory of Open Access Journals (Sweden)

    Hongtao Zheng

    2012-01-01

    Full Text Available In order to investigate H2 rich blowout limit at different blockage ratios and flow velocities, a CFD software FLUENT was used to simulate H2 burning flow field in bluff-body burner, and the software CHEMKIN was adopted to analyze the sensitivity of each elementary reaction. Composition Probability Density Function (C-PDF model was adopted to simulate H2 combustion field in turbulence flame. The numerical results show that reactions R2 and R9 possess the largest positive and negative temperature sensitivity. Temperature has a very important influence on these two reactions. When equivalence ratio is 1, the mixture is most ignitable, and the critical ignition temperature is 1550 K. There should be an optimal blockage ratio which can stabilize the flame best. When the blockage ratio remains unchanged, the relationship between H2 RBL and flow velocity is a logarithmic function. When the flow velocity remains unchanged, the relationship between H2 RBL and blockage ratio is a parabolic function. A complete extinction requires three phases: the temperature sudden decline in the main stream, the energy dissipation from the recirculation zone to the main stream, and the complete extinction of the flame.

  12. What happens between pure hydraulic and buckling mechanisms of blowout fractures?

    Science.gov (United States)

    Nagasao, Tomohisa; Miyamoto, Junpei; Shimizu, Yusuke; Jiang, Hua; Nakajima, Tatsuo

    2010-06-01

    The present study aims to evaluate how the ratio of the hydraulic and buckling mechanisms affects blowout fracture patterns, when these two mechanisms work simultaneously. Three-dimensional computer-aided-design (CAD)models were generated simulating ten skulls. To simulate impact, 1.2J was applied on the orbital region of these models in four patterns. Pattern 1: All the energy works to cause the hydraulic effect. Pattern 2: Two-thirds of the energy works to cause the hydraulic effect; one-third of the energy works to cause the buckling effect. Pattern 3: One-third of the energy works to cause the hydraulic effect; two-thirds of the energy works to cause the buckling effect. Pattern 4: The entire energy quantum works to cause the buckling effect. Using the finite element method, the regions where fractures were theoretically expected to occur were calculated and were compared between the four patterns. More fracture damage occurred for Pattern 1 than Pattern 2, and for Pattern 3 than for Pattern 4. The hydraulic and buckling mechanisms interact with one another. When these two mechanisms are combined, the orbital walls tend to develop serious fractures. Copyright (c) 2009 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

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

    International Nuclear Information System (INIS)

    Wan, Wing Suet; Lai, Vincent; Lau, Hin Yue; Wong, Yiu Chung; Poon, Wai Lun; Tan, Chong Boon

    2013-01-01

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

  14. Exposure of fish larvae to hydrocarbon concentration fields generated by subsurface blowouts

    International Nuclear Information System (INIS)

    Rye, Henrik; Johansen, Oeistein; Reed, Mark; Ekrol, Narve; Xiong Deqi

    2000-01-01

    As the oil activity outside the Norwegian coast moves towards north, the potential for conflict with the fishing industry increases. Reasons for this are the presence of spawning areas for important fish stocks like herring and cod, and also the technical development of subsurface solutions for the oil exploration, in-creasing the risks for the occurrence of subsurface blowouts. The paper explains how this potential for conflict can be described by means of numerical modelling techniques. The Haltenbanken area outside the western coast of Norway is selected as a field case. The modelling work involves underwater plume modelling as well as 3D modelling of ocean currents. The results from these modelling works are then combined with the modelling of the far-field transport and dilution of the underwater plume, and also the modelling of the spreading and transport of larvae from spawning areas. By combining the calculation of the concentration fields with the spreading calculations of the larvae, the exposure of a total larvae population (one year stock) can be estimated. The paper concludes that under unfavourable conditions, the overlap between the hydrocarbon concentration fields and the geographical distribution of larvae at its most vulnerable stage may cause a significant impact on a population level. (Author)

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

    Science.gov (United States)

    Vonk, Sophie M; Hollander, David J; Murk, AlberTinka J

    2015-11-15

    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 whether MOSSFA occurred in other large oil spills and identifies the main drivers of oil sedimentation. MOSSFA was found to have occurred during the IXTOC I blowout and possibly during the Santa Barbara blowout. Unfortunately, benthic effects were not sufficiently studied for the 52 spills we reviewed. However, based on the current understanding of drivers involved, we conclude that MOSSFA and related benthic contamination may be widespread. We suggest to collect and analyze sediment cores at specific spill locations, as improved understanding of the MOSSFA process will allow better informed spill responses in the future, taking into account possible massive oil sedimentation and smothering of (deep) benthic ecosystems. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Dynamic Simulation Analysis of Key Components of Special Transport Vehicle for Blowout Prevention Equipment Based on ADAMS

    Science.gov (United States)

    Yang, Huixiang; Zhao, Junpeng; Jiang, Dawei; Song, Guowa; Zhang, Bangcheng

    2017-10-01

    The mounted structure is a part of the whole vehicle, and determines the rationality of the vehicle design. First of all, through the ADAMS and CATIA data transmission interface, the use of CATIA to create a special model of the blowout prevention equipment, the model is imported into ADAMS; Secondly, ADAMS related settings in the definition of force, boundary conditions, and calculate the time step and other related parameters. Finally, the simulation results of the flipping mechanism are obtained by dynamic simulation analysis. The results show that the design of the truck loading structure meets the actual performance requirements.

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

    Science.gov (United States)

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

    2012-08-01

    Electron self-injection and acceleration until dephasing in the blowout regime is studied for a set of initial conditions typical of recent experiments with 100-terawatt-class lasers. Two different approaches to computationally efficient, fully explicit, 3D particle-in-cell modelling are examined. First, the Cartesian code vorpal (Nieter, C. and Cary, J. R. 2004 VORPAL: a versatile plasma simulation code. J. Comput. Phys. 196, 538) using a perfect-dispersion electromagnetic solver precisely describes the laser pulse and bubble dynamics, taking advantage of coarser resolution in the propagation direction, with a proportionally larger time step. Using third-order splines for macroparticles helps suppress the sampling noise while keeping the usage of computational resources modest. The second way to reduce the simulation load is using reduced-geometry codes. In our case, the quasi-cylindrical code calder-circ (Lifschitz, A. F. et al. 2009 Particle-in-cell modelling of laser-plasma interaction using Fourier decomposition. J. Comput. Phys. 228(5), 1803-1814) uses decomposition of fields and currents into a set of poloidal modes, while the macroparticles move in the Cartesian 3D space. Cylindrical symmetry of the interaction allows using just two modes, reducing the computational load to roughly that of a planar Cartesian simulation while preserving the 3D nature of the interaction. This significant economy of resources allows using fine resolution in the direction of propagation and a small time step, making numerical dispersion vanishingly small, together with a large number of particles per cell, enabling good particle statistics. Quantitative agreement of two simulations indicates that these are free of numerical artefacts. Both approaches thus retrieve the physically correct evolution of the plasma bubble, recovering the intrinsic connection of electron self-injection to the nonlinear optical evolution of the driver.

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

    International Nuclear Information System (INIS)

    Aibara, Ryuichi; Kawakita, Seiji; Matsumoto, Yasushi; Sadamoto, Masanori; Yumoto, Eiji.

    1996-01-01

    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)

  19. Dynamic Data-Driven Prediction of Lean Blowout in a Swirl-Stabilized Combustor

    Directory of Open Access Journals (Sweden)

    Soumalya Sarkar

    2015-09-01

    Full Text Available This paper addresses dynamic data-driven prediction of lean blowout (LBO phenomena in confined combustion processes, which are prevalent in many physical applications (e.g., land-based and aircraft gas-turbine engines. The underlying concept is built upon pattern classification and is validated for LBO prediction with time series of chemiluminescence sensor data from a laboratory-scale swirl-stabilized dump combustor. The proposed method of LBO prediction makes use of the theory of symbolic dynamics, where (finite-length time series data are partitioned to produce symbol strings that, in turn, generate a special class of probabilistic finite state automata (PFSA. These PFSA, called D-Markov machines, have a deterministic algebraic structure and their states are represented by symbol blocks of length D or less, where D is a positive integer. The D-Markov machines are constructed in two steps: (i state splitting, i.e., the states are split based on their information contents, and (ii state merging, i.e., two or more states (of possibly different lengths are merged together to form a new state without any significant loss of the embedded information. The modeling complexity (e.g., number of states of a D-Markov machine model is observed to be drastically reduced as the combustor approaches LBO. An anomaly measure, based on Kullback-Leibler divergence, is constructed to predict the proximity of LBO. The problem of LBO prediction is posed in a pattern classification setting and the underlying algorithms have been tested on experimental data at different extents of fuel-air premixing and fuel/air ratio. It is shown that, over a wide range of fuel-air premixing, D-Markov machines with D > 1 perform better as predictors of LBO than those with D = 1.

  20. Indications for repositioning of blow-out fractures of the orbital floor based on new objective criteria - tissue protrusion volumometry.

    Science.gov (United States)

    Kovar, Daniel; Voldrich, Zdenek; Voska, Pavel; Lestak, Jan; Astl, Jaromir

    2017-12-01

    The otolaryngologist often meets with fractures of the orbital floor. The most serious complication is diplopia, arising as a result of herniation of the orbital contents, with or without fixation of the inferior rectus muscle. The aim of our work was to create a mathematical model to calculate the volume of prolapsed soft tissue of the orbit in blow-out fractures, as a factor in deciding on the need for surgical treatment. In a retrospective study (2007-2013), we evaluated 80 patients with blow-out fractures, divided into two equal groups: 40 conservatively treated and 40 surgically treated patients. We created the model by measuring the fracture lines and herniation of the orbital soft tissues in the coronal and sagittal sections from CT images, equivalent to half the volume of a rotating ellipsoid. According to the proposed model, posterior and anterior fractures with a prolapse volume above 500 mm 3 , and anteroposterior fractures with a volume over 1400 mm 3 , are indicated for surgery. The volume of prolapsed soft tissue relative to the location of the fracture is the main indicator for selecting the best treatment procedure immediately after injury.

  1. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-09-01

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

  3. 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

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

    International Nuclear Information System (INIS)

    Adachi, Akihiko; Kobayashi, Eiichi; Watanabe, Yoshiyuki; Yoneyama, Tomoko S.; Hayasaka, Michihiro; Suzuki, Homare; Okamoto, Yoshitaka; Saeki, Naokatsu

    2011-01-01

    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

  5. Observations of Beach-Dune Interaction in Man-Made Trough Blowouts

    Science.gov (United States)

    Ruessink, G.; Arens, B.; Kuipers, M.; Van Onselen, E.; Donker, J.

    2016-02-01

    Dunes act as an indispensable natural safety barrier against marine flooding, are valuable natural environments, serve for the production of drinking water, and offer recreational opportunities. The safety function has dominated dune management in the Netherlands, as well as on other developed shores, for decades. Measures to minimize the seaward loss of foredune sand under storm wave attack have resulted in over-stabilized foredunes and, accordingly, have impoverished natural beauty and degraded biodiversity. Stabilized foredunes are nowadays increasingly reactivated by removing vegetation and by digging trenches that resemble natural trough blowouts as corridors for aeolian transport from the beach into the backdunes. Crucially, such measures see the beach-dune system as an integrated landscape, reconnecting the beach, foredune and backdunes through aeolian transport. This raises questions on how much sand is actually blown into the dunes, which factors affect this amount, and how effective the large-scale dune-restoration measures are. This contribution addresses the evolution of five trenches that were dug through the 20-m high foredune at the Dutch National Park Zuid-Kennemerland. The width of the trenches was 50 - 100 m, their cross-dune length was 60 - 100 m, and the heighest part of the valley floor was 9 m above mean sea level. Since their construction in the 2012/2013 winter the trenches have been surveyed approximately 3 times per year using airborne laser scanning or UAV photography, resulting in a multi-temporal data set of Digital Elevation Models (DEMs) with a 1x1 m resolution. Difference maps illustrate that the sidewalls of the trenches have steepened during the first two years after construction, but that their width and the height of the valley floor have remained largely unaltered. Landward of the trenches large sedimentation lobes have formed, which with time have grown both laterally and vertically. Locally, the lobe thickness now exceeds 5 m

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

    Science.gov (United States)

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

    2017-01-01

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

  7. Preventing Tire Blowout Accidents: A Perspective on Factors Affecting Drivers’ Intention to Adopt Tire Pressure Monitoring System

    Directory of Open Access Journals (Sweden)

    Kai-Ying Chen

    2018-04-01

    Full Text Available The aim of this study is to explore whether risk perception or anticipated regret is responsible for intensifying the participants’ intention to adopt a tire pressure monitoring system (TPMS to prevent a tire-related accident, and whether the optimism bias has a moderator effect between risk perception/anticipated regret and intention. With 274 valid questionnaires and PLS-SEM (partial least squares structural equation modeling analysis, the results indicate a significant positive relationship between risk perception and intention to adopt TPMS, but not between anticipated regret and intention. The moderator effect of optimism bias on risk perception and anticipated regret is not found in the model. The findings will prove useful for public service advertising campaigns by providing a basis for an understanding of the role of cognitive and emotional factors in tire-blowout accident prevention, thereby increasing the motivation for drivers in Taiwan to take advantage of the protection afforded them by using TPMS.

  8. Evolution of the Macondo well blowout: simulating the effects of the circulation and synthetic dispersants on the subsea oil transport.

    Science.gov (United States)

    Paris, Claire B; Hénaff, Matthieu Le; Aman, Zachary M; Subramaniam, Ajit; Helgers, Judith; Wang, Dong-Ping; Kourafalou, Vassiliki H; Srinivasan, Ashwanth

    2012-12-18

    During the Deepwater Horizon incident, crude oil flowed into the Gulf of Mexico from 1522 m underwater. In an effort to prevent the oil from rising to the surface, synthetic dispersants were applied at the wellhead. However, uncertainties in the formation of oil droplets and difficulties in measuring their size in the water column, complicated further assessment of the potential effect of the dispersant on the subsea-to-surface oil partition. We adapted a coupled hydrodynamic and stochastic buoyant particle-tracking model to the transport and fate of hydrocarbon fractions and simulated the far-field transport of the oil from the intrusion depth. The evaluated model represented a baseline for numerical experiments where we varied the distributions of particle sizes and thus oil mass. The experiments allowed to quantify the relative effects of chemical dispersion, vertical currents, and inertial buoyancy motion on oil rise velocities. We present a plausible model scenario, where some oil is trapped at depth through shear emulsification due to the particular conditions of the Macondo blowout. Assuming effective mixing of the synthetic dispersants at the wellhead, the model indicates that the submerged oil mass is shifted deeper, decreasing only marginally the amount of oil surfacing. In this scenario, the oil rises slowly to the surface or stays immersed. This suggests that other mechanisms may have contributed to the rapid surfacing of oil-gas mixture observed initially. The study also reveals local topographic and hydrodynamic processes that influence the oil transport in eddies and multiple layers. This numerical approach provides novel insights on oil transport mechanisms from deep blowouts and on gauging the subsea use of synthetic dispersant in mitigating coastal damage.

  9. Experimental investigation on ignition and lean blow-out performance of a multi-sector centrally staged combustor

    Science.gov (United States)

    Liu, Fuqiang; Zhang, Kaiyu; Mu, Yong; Liu, Cunxi; Yang, Jinhu; Xu, Gang; Zhu, Junqiang

    2014-10-01

    Improvement on extinction and pollution emission have become one of the most prominent research topics in gas turbine. It is widely recognized that the fuel/air mixture distribution in the recirculation zone is a critical factor in improving lean blow-out (LBO) and ignition. This paper proposed a new low emission scheme with fuel staged centrally and hybrid injector to improve flameout and emission. A relative small amount of fuel enters into central pilot airblast atomizer burner and then atomized by inner swirl air. The remaining majority of fuel is directly injected into vane channels of the primary swirler through a series of holes located on the sidewall of the main stage. Only pilot stage is fueled under ignition and lean flameout condition. The uniformity of fuel/air mixture distribution in the primary zone of the new design decreases NOX emission, meanwhile the fuel air mixture in pilot recirculation zone is locally rich to improve flameout and ignition. Experimental investigation was conducted to compare the new scheme with baseline design of dual-swirler in terms of LBO and ignition characteristics under the same condition in a multi-sector combustor. It is found that the fuel-air ratio of ignition limit and LBO decrease with the reference velocity increasing. The experimental results also show that the new scheme successfully improve lean blow-out and broaden the operation range of the combustor. The experimental results indicated that the centrally staged scheme can widen the operation boundary of the combustor and can provide guidance for design and optimization of combustion chamber.

  10. Application of Computer-Aided Designing and Rapid Prototyping Technologies in Reconstruction of Blowout Fractures of the Orbital Floor.

    Science.gov (United States)

    Tabaković, Saša Z; Konstantinović, Vitomir S; Radosavljević, Radivoje; Movrin, Dejan; Hadžistević, Miodrag; Hatab, Nur

    2015-07-01

    Traumatology of the maxillofacial region represents a wide range of different types of facial skeletal injuries and encompasses numerous treatment methods. Application of computer-aided design (CAD) in combination with rapid prototyping (RP) technologies and three-dimensional computed tomography techniques facilitates surgical therapy planning for efficient treatment. The purpose of this study is to determine the efficiency of individually designed implants of poly-DL-lactide (PDLLA) in the reconstruction of blowout fractures of the orbital floor. In the course of a surgical treatment, individually designed implants manufactured by CAD/RP technologies were used. Preoperative analysis and postoperative monitoring were conducted to evaluate the successfulness of orbital floor reconstruction using customized PDLLA implants, based on: presence of diplopia, paresthesia of infraorbital nerve, and presence of enophthalmos. In 6 of the 10 patients, diplopia completely disappeared immediately after surgical procedure. Diplopia gradually disappeared after 1 month in 3 patients, whereas in 1, it remained even after 6 months. In 7 patients, paresthesia disappeared within a month after surgery and in 3 patients within 2 months. Postoperative average Orbital volume (OV) of the injured side (13.333 ± 3.177) was significantly reduced in comparison with preoperative OV (15.847 ± 3.361) after reconstruction of the orbital floor with customized PDLLA implant (P orbit was not different compared with the OV of the uninjured orbit (P = 0.981). Reconstruction of blowout fractures of the orbital floor by an individually designed PDLLA implant combined with virtual preoperative modeling allows easier preoperative preparation and yields satisfactory functional and esthetic outcomes.

  11. Emissions due to the natural gas storage well-casing blowout at Aliso Canyon/SS-25

    Science.gov (United States)

    Herndon, Scott; Daube, Conner; Jervis, Dylan; Yacovitch, Tara; Roscioli, Joseph; Curry, Jason; Nelson, David; Knighton, Berk

    2017-04-01

    The pronounced increase in unconventional gas production in North America over the last fifteen years has intensified interest in understanding emissions and leaks in the supply chain from well pad to end use. Los Angeles, California is home 19 million consumers of natural gas in both industry and domestic end use. The well blowout at Aliso Canyon Natural Gas Storage Facility in the greater Los Angeles area was quantified using the tracer flux ratio method (TFR). Over 400 tracer plume transects were collected, each lasting 15-300 seconds, using instrumentation aboard a mobile platform on 25 days between December 21, 2015 and March 9, 2016. The leak rate from October 23rd to February 11th has been estimated here using a combination of this work (TFR) and the flight mass balance (FMB) data [Conley et al., 2016]. This estimate relies on the TFR data as the most specific SS-25 emission dataset. Scaling the FMB dataset, the leak rate is projected from Oct 23rd to December 21th. Adding up the emissions inferred and measured suggests a total leak burden of 86,022 ± 8,393 metric tons of methane. This work quantified the emissions during the "bottom kill" procedure which halted the primary emission leak. The ethane to methane enhancement ratio observed downwind of the leak site is consistent with the content of ethane in the natural gas at this site and provides definitive evidence that the methane emission rate quantified via tracer flux ratio is not due to a nearby landfill or other potential biogenic sources. Additionally, the TFR approach employed here is assessing only the leaks due to the SS-25 well blowout and excludes other possible emissions at the facility.

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

    Science.gov (United States)

    Rzymska-Grala, Iwona; Palczewski, Piotr; Błaż, Marcin; Zmorzyński, Michał; Gołębiowski, Marek; Wanyura, Hubert

    2012-04-01

    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.

  13. EUB post-incident report : Celtic Exploration Ltd. well servicing incident : blowout and fire, August 9, 2005

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-02-06

    A blowout and fire occurred on August 9, 2005 at a sour oil well during a routine well completion operation. The Alberta Energy and Utilities Board (EUB) was notified by Celtic Exploration Ltd., the well operator which implemented the emergency response plan (ERP). The 21 residents in the area were evacuated along with 100 campers from a nearby provincial park. The release concentration of hydrogen sulphide from the well was 4.5 moles/kilomole. The well was brought under control the next day by pumping calcium chloride water down the well. The evacuees were allowed to return. One fatality and 2 injuries were sustained by workers at the site and the service rig was destroyed by fire. Celtic assessed the incident as an uncontrollable event. The EUB conducted an investigation that focused on the cause of the incident, the risk to public safety, environmental impacts, and the conservation of the resource. The worker fatalities and injuries are being investigated by the Alberta Human Resources and Employment, Workplace Health and Safety. It was determined that the blowout was caused by an explosion within the swab tree assembly at the top of the well. An explosive situation was created when a mix of hydrocarbons and air was ignited. However, the source of ignition could not be definitively determined. The EUB also assessed the implementation of Celtic's ERP and the actions taken to manage the incident. The EUB determined that while several ERP measures were managed appropriately, some specific elements were deficient, particularly communication during the incident. About 228 cubic metres of contaminated soil was removed from the well lease to a waste site. The total production loss is estimated at 4 m{sup 3} of oil and 12,000 m{sup 3} of raw solution gas. Four follow-up actions that Celtic has committed to were described along with the EUB's directive 033 regarding well servicing and completions operations and requirements regarding the potential for explosive

  14. 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.

  15. Hydrocarbon composition and concentrations in the Gulf of Mexico sediments in the 3 years following the Macondo well blowout.

    Science.gov (United States)

    Babcock-Adams, Lydia; Chanton, Jeffrey P; Joye, Samantha B; Medeiros, Patricia M

    2017-10-01

    In April of 2010, the Macondo well blowout in the northern Gulf of Mexico resulted in an unprecedented release of oil into the water column at a depth of approximately 1500 m. A time series of surface and subsurface sediment samples were collected to the northwest of the well from 2010 to 2013 for molecular biomarker and bulk carbon isotopic analyses. While no clear trend was observed in subsurface sediments, surface sediments (0-3 cm) showed a clear pattern with total concentrations of n-alkanes, unresolved complex mixture (UCM), and petroleum biomarkers (terpanes, hopanes, steranes) increasing from May to September 2010, peaking in late November 2010, and strongly decreasing in the subsequent years. The peak in hydrocarbon concentrations were corroborated by higher organic carbon contents, more depleted Δ 14 C values and biomarker ratios similar to those of the initial MC252 crude oil reported in the literature. These results indicate that at least part of oil discharged from the accident sedimented to the seafloor in subsequent months, resulting in an apparent accumulation of hydrocarbons on the seabed by the end of 2010. Sediment resuspension and transport or biodegradation may account for the decrease in sedimented oil quantities in the years following the Macondo well spill. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Well control in case of offshore blowout. Evaluation of proposed means for well shut-in, received from independent private persons

    Energy Technology Data Exchange (ETDEWEB)

    Westergaard, R.H.

    1980-12-01

    Three ideas from three independent persons are evaluated. The first one is a combined hot tapping, diverting and shut-in tool. It may, if worked out, have some merit provided the well has a suitable spool piece on which it can be used. The second proposal is a queer idea for shutting in a blowout. It is no good. The third one is a proposal to use a military tank as a platform for underwater capping. It may be worth consideration. 1 drawing.

  17. Transarterial endovascular treatment in the management of life-threatening carotid blowout syndrome in head and neck cancer patients: review of the literature.

    Science.gov (United States)

    Dequanter, D; Shahla, M; Paulus, P; Aubert, C; Lothaire, P

    2013-12-01

    Carotid blowout syndrome is a rare but devastating complication in patients with head and neck malignancy, and is associated with high morbidity and mortality. Bleeding from the carotid artery or its branches is a well-recognized complication following treatment or recurrence of head and neck cancer. It is an emergency situation, and the classical approach to save the patient's life is to ligate the carotid artery. But the surgical treatment is often technically difficult. Endovascular therapies were recently reported as good alternatives to surgical ligation. Retrospective review of three cases of acute or threatened carotid hemorrhage managed by endovascular therapies. Two patients presented with acute carotid blowout, and one patient with a sentinel bleed. Two patients had previously been treated with surgery and chemo radiation. One patient was treated by chemo radiation. Two had developed pharyngocutaneous fistulas, and one had an open necrosis filled wound that surrounded the carotid artery. In two patients, stent placement resolved the acute hemorrhage. In one patient, superselective embolization was done. Mean duration follow-up was 10.2 months. No patient had residual sequelae of stenting or embolization. Management of carotid blow syndrome is very critical and difficult. A multidisciplinary approach is very important in the management of carotid blow syndrome. Correct and suitable management can be life saving. An endovascular technique is a good and effective alternative with much lower morbidity rates than surgical repair or ligation. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  18. Blowout heroes : while his crew mate risked fire and falling rock to save him, Curly Slater fought right to the last breath

    Energy Technology Data Exchange (ETDEWEB)

    Louie, J.

    2008-11-15

    This article discussed a blow-out that resulted in a fatality at a drilling rig near Helmut, British Columbia (BC). The blowout caused a column of fire, drilling mud, and rock to explode from the floor of the rig. As the rig's derrickman was trapped when drilling mud caked onto his easy rider cable and froze the escape sliding mechanism. The derrickman fell and was left dangling by his harness. Crew members spotted him from a distance and returned to the site in order to unhook the easy rider cable from the manifold shack and move the steel line to a location that would allow him to descend more easily. The derrickman was unable to un-jam his fall arrestor. He freed himself using his own strength, seized a cable, but lost his grip while still 75 feet in the air and fell to his death. The tragedy was caused by the presence of a very large gas pocket encountered at an unusually shallow depth. Several of the crew members have been unable to continue working in the oil and gas industry, due to the psychological trauma of witnessing the man's death. The Canadian Association of Oilwell Drilling Contractors (CAODC) has issued awards of merit for the crew men who attempted to save the derrickman, and the entire crew will receive medals of bravery from the Governor General of Canada. 2 figs.

  19. Reconstruction of orbital floor blow-out fractures with autogenous iliac crest bone: a retrospective study including maxillofacial and ophthalmology perspectives.

    Science.gov (United States)

    O'Connell, John Edward; Hartnett, Claire; Hickey-Dwyer, Marie; Kearns, Gerard J

    2015-03-01

    This is a 10-year retrospective study of patients with an isolated unilateral orbital floor fracture reconstructed with an autogenous iliac crest bone graft. The following inclusion criteria applied: isolated orbital floor fracture without involvement of the orbital rim or other craniofacial injuries, pre-/post-operative ophthalmological/orthoptic follow-up, pre-operative CT. Variables recorded were patient age and gender, aetiology of injury, time to surgery, follow-up period, surgical morbidity, diplopia pre- and post-operatively (Hess test), eyelid position, visual acuity, and the presence of en-/or exophthalmos (Hertel exophthalmometer). Twenty patients met the inclusion criteria. The mean age was 29 years. The mean follow up period was 26 months. No patient experienced significant donor site morbidity. There were no episodes of post-operative infection or graft extrusion. Three patients had diplopia in extremes of vision post-operatively, but no interference with activities of daily living. One patient had post-operative enophthalmos. Isolated orbital blow-out fractures may be safely and predictably reconstructed using autogenous iliac crest bone. The rate of complications in the group of patients studied was low. The value of pre- and post-operative ophthalmology consultation cannot be underestimated, and should be considered the standard of care in all patients with orbitozygomatic fractures, in particular those with blow-out fractures. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  20. 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)

    Oweis, Yaseen; Gemmete, Joseph J.; Chaudhary, Neeraj; Pandey, Aditya; Ansari, Sameer

    2011-01-01

    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.

  1. Estudo do efeito de um "Riser Blowout" na perfuração de poços de petroleo em aguas profundas

    OpenAIRE

    Heitor Rodrigues de Paula Lima

    1991-01-01

    Resumo: Esta dissertação apresenta uma análise do comportamento da pressão dos fluidos que ocorre durante o especial acidente na perfuração de um poço submarino de petróleo conhecido como "Riser Blowout" ( * ). O modelo usado neste estudo baseia-se na solução do sistema de equações diferenciais parciais que governam o fluxo ascendente da mistura bifásica fluido de perfuração/ gás dentro do espaço anular entre a coluna de perfuração e o "marine riser". As perdas de carga devido a aceleração do...

  2. Anomalously High Recruitment of the 2010 Gulf Menhaden (Brevoortia patronus) Year Class: Evidence of Indirect Effects from the Deepwater Horizon Blowout in the Gulf of Mexico.

    Science.gov (United States)

    Short, Jeffrey W; Geiger, Harold J; Haney, J Christopher; Voss, Christine M; Vozzo, Maria L; Guillory, Vincent; Peterson, Charles H

    2017-07-01

    Gulf menhaden (Brevoortia patronus) exhibited unprecedented juvenile recruitment in 2010 during the year of the Deepwater Horizon well blowout, exceeding the prior 39-year mean by more than four standard deviations near the Mississippi River. Abundance of that cohort remained exceptionally high for two subsequent years as recruits moved into older age classes. Such changes in this dominant forage fish population can be most parsimoniously explained as consequences of release from predation. Contact with crude oil induced high mortality of piscivorous seabirds, bottlenose dolphin (Tursiops truncatus), waders, and other fish-eating marsh birds, all of which are substantial consumers of Gulf menhaden. Diversions of fresh water from the Mississippi River to protect coastal marshes from oiling depressed salinities, impairing access to juvenile Gulf menhaden by aquatic predators that avoid low-salinity estuarine waters. These releases from predation led to an increase of Gulf menhaden biomass in 2011 to 2.4 million t, or more than twice the average biomass of 1.1 million t for the decade prior to 2010. Biomass increases of this magnitude in a major forage fish species suggest additional trophically linked effects at the population-, trophic-level and ecosystem scales, reflecting an heretofore little appreciated indirect effect that may be associated with major oil spills in highly productive marine waters.

  3. 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)

    Chang, F.-C.; Luo, C.-B.; Lirng, J.-F.; Lin, C.-J.; Wu, H.-M.; Hung, S.-C.; Guo, W.-Y.; Teng, M.M.H.; Chang, C.-Y.

    2013-01-01

    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

  4. Kuwaiti oil wells blowout - aspects and effects

    International Nuclear Information System (INIS)

    Al-Jassim, F.

    1992-01-01

    When the Iraqi troops were forced to leave Kuwait, they left behind them the greatest oil catastrophe human beings have ever experienced. Fire plumes of tons of gases of principal pollutants, hydrocarbons, soot and associated metals were ejected up to a height of about 5 km. The retreating forces blew off about 1200 wells all over Kuwait fields. Of these 1200 wells, 614 are on fire. Four firefighting companies were hired to start work immediately after the liberation of Kuwaiti to control these wells. Three of these companies were from the U.S.A. and one from Canada. The number of these companies steadily increased along with logistical support. There are now 28 teams made up of private and multinational companies. This paper will concentrate on two main aspects. The first part will focus on the up-to-date engineering aspects of bringing the blown-out wells under control, focusing on oil well fires and the difficulties encountered, such as equipment availability, ordnance clearance and logistical support. The paper then describes the procedures used to control the wells, and the steps taken to reach this aim are presented. Finally the number of wells controlled, area-wise in different fields, with their original status, is also introduced. The second part will concentrate on the environmental aspects, covering the impact of the plumes on air quality, air pollution and health. The paper then discusses the effect on marine environment, vegetation and the soil. Finally, a forecast, conclusions and recommendations are presented. (author)

  5. Pulsar Wind Bubble Blowout from a Supernova

    Energy Technology Data Exchange (ETDEWEB)

    Blondin, John M. [Department of Physics, North Carolina State University, Raleigh, NC 27695-8202 (United States); Chevalier, Roger A., E-mail: blondin@ncsu.edu [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States)

    2017-08-20

    For pulsars born in supernovae, the expansion of the shocked pulsar wind nebula is initially in the freely expanding ejecta of the supernova. While the nebula is in the inner flat part of the ejecta density profile, the swept-up, accelerating shell is subject to the Rayleigh–Taylor instability. We carried out two- and three-dimensional simulations showing that the instability gives rise to filamentary structure during this initial phase but does not greatly change the dynamics of the expanding shell. The flow is effectively self-similar. If the shell is powered into the outer steep part of the density profile, the shell is subject to a robust Rayleigh–Taylor instability in which the shell is fragmented and the shocked pulsar wind breaks out through the shell. The flow is not self-similar in this phase. For a wind nebula to reach this phase requires that the deposited pulsar energy be greater than the supernova energy, or that the initial pulsar period be in the ms range for a typical 10{sup 51} erg supernova. These conditions are satisfied by some magnetar models for Type I superluminous supernovae. We also consider the Crab Nebula, which may be associated with a low energy supernova for which this scenario applies.

  6. Survived ileocecal blowout from compressed air.

    Science.gov (United States)

    Weber, Marco; Kolbus, Frank; Dressler, Jan; Lessig, Rüdiger

    2011-03-01

    Industrial accidents with compressed air entering the gastro-intestinal tract often run fatally. The pressures usually over-exceed those used by medical applications such as colonoscopy and lead to vast injuries of the intestines with high mortality. The case described in this report is of a 26-year-old man who was harmed by compressed air that entered through the anus. He survived because of fast emergency operation. This case underlines necessity of explicit instruction considering hazards handling compressed air devices to maintain safety at work. Further, our observations support the hypothesis that the mucosa is the most elastic layer of the intestine wall.

  7. MR imaging of orbital blow-out fractures

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Tsutomu; Sawada, Satoshi; Shikaura, Sachiko; Uda, Mitsunobu; Kawa, Soukichi; Tanaka, Yoshimasa; Miki, Hirohiko; Yamanouchi, Yasuo; Inagaki, Ryusuke

    1988-02-01

    We investigated the method of visualization in the MRI of 5 cases of orbital floor fracture. With a spin-echo image with a short TR and TE, the fatty component and the muscle component could be identified easily. In a routine case of orbital floor fracture, a good demonstration could be obtained with an oblique sagittal view along with the optic nerve. However, in some cases, coronal views were also necessary.

  8. MT Lajpatrai blow-out studies at Bombay harbour

    Digital Repository Service at National Institute of Oceanography (India)

    Fondekar, S.P.

    The area around the tanker MT Lajpatrai was monitored for oil pollution studies. Measurements were carried out on the concentration of petroleum hydrocarbons in water and sediment samples along with visual observations on oil slicks...

  9. 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.

  10. 30 CFR 250.1624 - Blowout prevention equipment.

    Science.gov (United States)

    2010-07-01

    ... station and one BOP-control station on the rig floor; and (5) A choke line and a kill line each equipped with two full-opening valves and a choke manifold. One of the choke-line valves and one of the kill...

  11. 30 CFR 250.615 - Blowout prevention equipment.

    Science.gov (United States)

    2010-07-01

    ... operations with the tree removed must meet the appropriate standards from the following table: When The... secondary source of pneumatic supply, must be equipped with manual overrides, or alternately, other devices...

  12. 30 CFR 250.515 - Blowout prevention equipment.

    Science.gov (United States)

    2010-07-01

    ... the appropriate standards from the following table: When The minimum BOP stack must include (1) The... without a secondary source of pneumatic supply, must be equipped with manual overrides, or alternately...

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

    International Nuclear Information System (INIS)

    Bakker, Sjoerd

    2010-01-01

    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.

  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

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

    Science.gov (United States)

    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, 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. PMID:26172639

  17. 30 CFR 250.1610 - Blowout preventer systems and system components.

    Science.gov (United States)

    2010-07-01

    ... as specified under paragraphs (e) and (f) of this section. The pipe rams shall be of proper size to fit the drill pipe in use. (c) Working pressure. The working-pressure rating of any BOP shall exceed... of hydraulic operations if rig air is lost. (2) An automatic backup to the accumulator system. The...

  18. A Wrapping Method for Inserting Titanium Micro-Mesh Implants in the Reconstruction of Blowout Fractures

    Directory of Open Access Journals (Sweden)

    Tae Joon Choi

    2016-01-01

    Full Text Available Titanium micro-mesh implants are widely used in orbital wall reconstructions because they have several advantageous characteristics. However, the rough and irregular marginal spurs of the cut edges of the titanium mesh sheet impede the efficacious and minimally traumatic insertion of the implant, because these spurs may catch or hook the orbital soft tissue, skin, or conjunctiva during the insertion procedure. In order to prevent this problem, we developed an easy method of inserting a titanium micro-mesh, in which it is wrapped with the aseptic transparent plastic film that is used to pack surgical instruments or is attached to one side of the inner suture package. Fifty-four patients underwent orbital wall reconstruction using a transconjunctival or transcutaneous approach. The wrapped implant was easily inserted without catching or injuring the orbital soft tissue, skin, or conjunctiva. In most cases, the implant was inserted in one attempt. Postoperative computed tomographic scans showed excellent placement of the titanium micro-mesh and adequate anatomic reconstruction of the orbital walls. This wrapping insertion method may be useful for making the insertion of titanium micro-mesh implants in the reconstruction of orbital wall fractures easier and less traumatic.

  19. Chemical Safety Alert: Shaft Blow-Out Hazard of Check and Butterfly Valves

    Science.gov (United States)

    Certain types of check and butterfly valves can undergo shaft-disk separation and fail catastrophically, even when operated within their design limits of pressure and temperature, causing toxic/flammable gas releases, fires, and vapor cloud explosions.

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

    Directory of Open Access Journals (Sweden)

    Tingting Yang

    2016-09-01

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

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

    NARCIS (Netherlands)

    Bakker, S.

    2010-01-01

    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

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

    Science.gov (United States)

    2012-04-01

    Progress in Energy and Combustion Science 35, 98–120. 4DeZubay, E. A., 1950, “Characteristics of Disk-Controlled Flame,” Aero Digest , 54-57...J. M., Fisher, T. C., Frankel, S. H., Sekar, B., and Kiel, B. V., 2008, “ CFD Predictions of Damköhler Number Fields for Reduced Order Modeling of V

  3. 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.

  4. 30 CFR 250.516 - Blowout preventer system tests, inspections, and maintenance.

    Science.gov (United States)

    2010-07-01

    ... District Manager may require testing every 7 days if conditions or BOP performance warrant. (b) BOP test... between control stations and pods. If a control station or pod is not functional, you must suspend further... at least every 30 days; (5) Function test annulars and rams every 7 days; (6) Pressure-test variable...

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

    Science.gov (United States)

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

    2016-12-01

    When immersed in intrinsically motivating activities, individuals actively seek optimal challenge, which generally brings the most satisfaction as they play hard and finally win. To better simulate real-life scenarios in the controlled laboratory setting, a two-player online StopWatch (SW) game was developed, whose format is similar to that of a badminton tournament. During the game, a male opponent played by a confederate ensured that the same-sex participant paired with him won both matches, one with a wide margin (the lack of challenge condition) and another with a narrow one (the optimal challenge condition). Electrophysiological data were recorded during the entire experiment. An enlarged Stimulus-preceding negativity (SPN) was observed in the optimal challenge condition, indicating a more concentrated anticipatory attention toward the feedback and a stronger intrinsic motivation during close games. Thus, this study provided original neural evidence for predictions of Self-determination theory (SDT) and Flow theory, and confirmed and emphasized the significant role of optimal challenge in promoting one's intrinsic motivation to win. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. 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.

  7. The Montara Oil Spill: A 2009 Well Blowout in the Timor Sea.

    Science.gov (United States)

    Spies, R B; Mukhtasor, M; Burns, K A

    2017-07-01

    A well on the Montara platform on the Australian continental shelf blew out in August 2009 and spilled oil into the Timor Sea for 74 days. The oil, estimated at as much as 23.5 million L in total volume, spread over a large area of the shelf and eventually into Indonesian waters. This paper documents, through published literature, reports of both Australian and Indonesian governments and observations of coastal residents and fishermen the spread of the oil and attempts to estimate its impact. The lack of observers on the ocean and baseline, pre-spill data on populations of marine organisms, and delays in deploying scientific surveys after the spill severely limited efforts by the Australian government to determine damage in its territorial waters. Biological survey work was not done in Indonesian waters, but coastal residents attested to relatively severe impacts to algal farms. In addition fish landings declined in one port in southwest Timor Island.

  8. Ileal blowout due to ileal atresia in a donor with twinto- twin ...

    African Journals Online (AJOL)

    Twin-to-twin transfusion syndrome (TTTS) occurs in 10% of monochorionic twin pregnancies, and can lead to a variety of complications due to imbalanced blood flow across placental vascular communications. In this report, we describe a case of intestinal injury in TTTS after fetoscopic laser ablation of the communicating ...

  9. The functional outcome of blow-out fractures managed surgically and conservatively

    DEFF Research Database (Denmark)

    Felding, Ulrik Ascanius; Rasmussen, Janne; Toft, Peter Bjerre

    2016-01-01

    or conservatively. The study design is a retrospective cohort study and the setting is Tertiary care University Hospital. The participants include patients with isolated BOFs admitted to our Trauma Unit from 2010 to 2013. Of the 100 consecutive patients included, 60 had available follow-up data. The presence...... of diplopia and enophthalmus was determined by reviewing the medical records. Data from the patients' initial consultation and their 3-month follow-up were also collected. Of the 60 patients whose data could be analysed, 36 had been managed surgically and 24 conservatively. Of the patients managed surgically......, 25 had diplopia in peripheral gaze before surgery and 12 at 3-month follow-up. Nine had diplopia in primary gaze before surgery and none at 3-month follow-up. Five had enophthalmus before surgery and two at 3-month follow-up. Of the patients managed conservatively, eight had diplopia in peripheral...

  10. 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)

  11. 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

  12. A simple strategy to decrease fatal carotid blowout syndrome after stereotactic body reirradiaton for recurrent head and neck cancers

    International Nuclear Information System (INIS)

    Yazici, Gozde; Gurkaynak, Murat; Ozyigit, Gokhan; Sanlı, Tolga Yusuf; Cengiz, Mustafa; Yuce, Deniz; Gultekin, Melis; Hurmuz, Pervin; Yıldız, Ferah; Zorlu, Faruk; Akyol, Fadil

    2013-01-01

    This study aimed to compare the therapeutic outcomes and fatal carotid blow out syndrome (CBOS) incidence rates between two different stereotactic body radiotherapy (SBRT) protocols. The study included 75 patients with inoperable locally recurrent head and neck cancer treated with SBRT in our department between June 2007 and March 2011. The first 43 patients were treated sequentially (group I). Then our SBRT protocol was changed due to the high rate of CBOS, and the following 32 patients were treated every other day in a prospective institutional protocol (group II). Median overall survival in group I and group II was 11 months and 23 months, respectively (P = 0.006). We observed 11 cases of CBOS. Only 1 of 7 patients (14%) with CBOS survived in group I, whereas 2 of 4 patients (50%) in group II remain alive. CBOS free median overall survivals were 9 months, and 23 months in group I and group II respectively (P = 0.002). The median radiation dose received by the carotid artery in patients with CBOS was 36.5 Gy (range: 34–42.8 Gy), versus 34.7 Gy (range: 0–44 Gy) in the patients that didn’t have CBOS (P = 0.15). CBOS did not occur in any of the patients with a maximum carotid artery radiation dose <34 Gy. Every other day SBRT protocol for re-irradiation of recurrent head and neck cancer is promising in terms of decreasing the incidence of fatal CBOS

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

    Science.gov (United States)

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

    2015-01-01

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

  14. 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].

  15. 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.

  16. 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.

  17. 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.

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

    Science.gov (United States)

    Pattee, O H; Franson, J C

    1982-04-01

    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.

  19. 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.

  20. 30 CFR 250.213 - What general information must accompany the EP?

    Science.gov (United States)

    2010-07-01

    ... description and discussion of any new or unusual technology (see definition under § 250.200) you will use to... hydrocarbons. Include the estimated flow rate, total volume, and maximum duration of the potential blowout...

  1. Passive Airbag Vent Control Valve Study

    National Research Council Canada - National Science Library

    Rosato, Nicholas

    1999-01-01

    .... The venting candidates studied consisted of two different linear spring check valve designs, a magnetostatic check valve design, along with two precision release blowout vents configured using a four...

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

    Energy Technology Data Exchange (ETDEWEB)

    KOZLOWSKI, S.D.

    2005-01-06

    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.

  3. 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.

  4. Control rod blow out protection system

    International Nuclear Information System (INIS)

    Dietrich, J.R.; Flinn, W.S.; Groves, M.D.

    1979-01-01

    An absorber element blow-out protection system for a nuclear reactor having a pressure vessel through which a coolant is circulated. The blow-out protection system includes devices which hydraulically couple groups of guide tubes in which the absorber elements move, the coupling devices limiting coolant lift flow rate to a level commensurate with the raising of individual absorber elements but insufficient to raise a plurality of absorber elements simultaneously

  5. a case study of Deepwater Horizon oil spill at the Gulf of Mexico ...

    African Journals Online (AJOL)

    On 20thApril, 2010, Deepwater Horizon oil spill occurred at the Gulf of Mexico, United States of America where large amount of oil spilled in to the water as a result of wellhead blowout from the rig. The spill marked as the largest oil spill ever in the USA and causes large impacts to the marine species and the surrounding ...

  6. 46 CFR 11.470 - Officer endorsements as offshore installation manager.

    Science.gov (United States)

    2010-10-01

    ... control training program for the driller, toolpusher, or operator representative position; (iv) A... from a U.S. Minerals Management Service approved blowout prevention and well control training program... official which: (A) Provides a description of the applicant's experience and company qualifications program...

  7. Retrospective Morphometric Analysis of the Infraorbital Foramen ...

    African Journals Online (AJOL)

    2017-10-26

    Oct 26, 2017 ... E-mail: omiloglu@hotmail.com might occur in the anterior and superior walls during the surgical treatments such as rhinoplasty, Caldwell-Luc surgical procedures, tumor surgery, orbita basis reduction. (blow-out), malar region fractures, and Le Fort type-I osteotomy.[3] Therefore, knowing the localization of ...

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

    International Nuclear Information System (INIS)

    Boak, D.M.; Dotson, L.; Aguilar, R.

    1997-01-01

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

  9. 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

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

    NARCIS (Netherlands)

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

    2016-01-01

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

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

    International Nuclear Information System (INIS)

    Anon.

    2010-01-01

    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.

  12. Demography and monitoring of Welsh's milkweed (Asclepias welshii) at Coral Pink Sand Dunes

    Science.gov (United States)

    Brent C. Palmer; L. Armstrong

    2001-01-01

    Results are presented of a 12-year monitoring program on the Coral Pink Sand Dunes and Sand Hills populations of the threatened Welsh's milkweed, Asclepias welshii N & P Holmgren. The species is an early sera1 member of the dune flora, colonizing blowouts and advancing with shifting dunes. When an area stabilizes and other vegetation encroaches, A. welshii is...

  13. 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

  14. Desensitizing Flame Structure and Exhaust Emissions to Flow Parameters in an Ultra-Compact Combustor

    Science.gov (United States)

    2012-03-22

    fuel .... 9 Figure 2.4: UNICORN model of hydrogen in air flame front propagation under the loading condition (a) 10 g’s and (b) 500 g’s...Lean Blowout ...................................................................................8 UNICORN Unsteady Ignition and Combustion with...computationally recreate Lewis’ experimental results. Using the Unsteady Ignition and 9 Combustion with Reactions ( UNICORN ) code, flame propagation

  15. Download this PDF file

    African Journals Online (AJOL)

    PT WAKODE (MS): Professor in ENT, Department of ENT, BP Koirala Institute of Health Sciences, Dharan, Nepal. ABSTRACT. Blowout fractures occur when direct blunt force is applied to the globe and orbit. The patient in this case had extensive fractures of the medial wall, lateral wall, floor and roof of the right orbit ...

  16. 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.

  17. Diplopia and Orbital Wall Fractures

    NARCIS (Netherlands)

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

    2014-01-01

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

  18. Diplopia and orbital wall fractures

    NARCIS (Netherlands)

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

    2014-01-01

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

  19. Evidence of sulfate-dependent anaerobic methane oxidation within an area impacted by coalbed methane-related gas migration

    Science.gov (United States)

    The rapid development of unconventional gas resources has been accompanied by an increase in public awareness regarding the potential effects of drilling operations on drinking water sources. Incidents have been reported involving blowouts (e.g., Converse County, WY; Lawrence Tow...

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

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2010-06-15

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

  1. 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.

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

    International Nuclear Information System (INIS)

    Edwards, W.C.

    1992-01-01

    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

  3. the feasibility of implementing the united nations guiding principles

    African Journals Online (AJOL)

    RAYAN_

    of Ogoni People (MOSOP).23 The comprehensive United Nations Environment. Programme (UNEP) report in its assessment of about 200 locations in Ogoni, found that due to the decades of oil exploration and blowouts, oil spillage, oil slicks, gas flaring and waste discharge, the once alluvial soil of the Niger. Delta is no ...

  4. 30 CFR 250.444 - What are the choke manifold requirements?

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What are the choke manifold requirements? 250... Blowout Preventer (bop) System Requirements § 250.444 What are the choke manifold requirements? (a) Your BOP system must include a choke manifold that is suitable for the anticipated surface pressures...

  5. The sensitivity of the surface oil signature to subsurface dispersant injection and weather conditions.

    Science.gov (United States)

    Daae, Ragnhild L; Skancke, Jørgen; Brandvik, Per Johan; Faksness, Liv-Guri

    2018-02-01

    Subsea blowouts have the potential to spread oil across large geographical areas, and subsea dispersant injection (SSDI) is a response option targeted at reducing the impact of a blowout, especially reducing persistent surface oil slicks. Modified Weber scaling was used to predict oil droplet sizes with the OSCAR oil spill model, and to evaluate the surface oil volume and area when using SSDI under different conditions. Generally, SSDI reduces the amount of oil on the surface, and creates wider and thinner surface oil slicks. It was found that the reduction of surface oil area and volume with SSDI was enhanced for higher wind speeds. Overall, given the effect of SSDI on oil volume and weathering, it may be suggested that tar ball formation, requiring thick and weathered oil, could possibly be reduced when SSDI is used. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Well Integrity for Natural Gas Storage in Depleted Reservoirs and Aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Freifeld, Barry [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Oldenburg, Curtis [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Jordan, Preston [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Pan, Lehua [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Perfect, Scott [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Morris, Joseph [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); White, Joshua [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bauer, Stephen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Blankenship, Douglas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Roberts, Barry [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bromhal, Grant [National Energy Technology Lab. (NETL), Morgantown, WV (United States); Glosser, Deborah [National Energy Technology Lab. (NETL), Morgantown, WV (United States); Wyatt, Douglas [National Energy Technology Lab. (NETL), Morgantown, WV (United States); Rose, Kelly [National Energy Technology Lab. (NETL), Morgantown, WV (United States)

    2016-09-01

    The 2015-2016 Aliso Canyon/Porter Ranch natural gas well blowout emitted approximately 100,000 tonnes of natural gas (mostly methane, CH4) over four months. The blowout impacted thousands of nearby residents, who were displaced from their homes. The high visibility of the event has led to increased scrutiny of the safety of natural gas storage at the Aliso Canyon facility, as well as broader concern for natural gas storage integrity throughout the country. This report presents the findings of the DOE National Laboratories Well Integrity Work Group efforts in the four tasks. In addition to documenting the work of the Work Group, this report presents high priority recommendations to improve well integrity and reduce the likelihood and consequences of subsurface natural gas leaks.

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

    Science.gov (United States)

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

    2015-01-01

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

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

    International Nuclear Information System (INIS)

    Berg, H. Rogier van den; Leijdekkers, Vanessa J.; Vahl, Anco

    2006-01-01

    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

  9. Disturbance In Dry Coastal Dunes 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 areas...... on plant and arthropod composition. Indicator species analysis revealed plant and arthropod species indicative for different disturbances. Plant and arthropod species richness and the number of annual plant species generally increased with disturbance, and plant and arthropod richness and composition...... responded differently to different disturbances. Arthropod communities were more diverse in disturbed plots and hosted species often found in early successional habitats of potential conservation value. Disturbance promoted β-diversity, but affected plants more than arthropods, likely because...

  10. 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.

  11. Geopressures

    Energy Technology Data Exchange (ETDEWEB)

    Stuart, Charles A.

    1970-01-30

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

  12. 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...

  13. Hydrocarbon-Degrading Bacteria Exhibit a Species-Specific Response to Dispersed Oil while Moderating Ecotoxicity

    OpenAIRE

    Overholt, Will A.; Marks, Kala P.; Romero, Isabel C.; Hollander, David J.; Snell, Terry W.; Kostka, Joel E.

    2016-01-01

    The Deepwater Horizon blowout in April 2010 represented the largest accidental marine oil spill and the largest release of chemical dispersants into the environment to date. While dispersant application may provide numerous benefits to oil spill response efforts, the impacts of dispersants and potential synergistic effects with crude oil on individual hydrocarbon-degrading bacteria are poorly understood. In this study, two environmentally relevant species of hydrocarbon-degrading bacteria wer...

  14. Analysis of Flow Migration in an Ultra-Compact Combustor

    Science.gov (United States)

    2011-03-01

    Computational Fluid Dynamics . . . . . . . . . . . . . . . 6 UNICORN Unsteady Ignition and Combustion with Reactions . . . . 8 LBO Lean Blowout...the magnitude of enhanced flame speeds due to g- loading using the UNICORN CFD code. The study examined flame propagation for a hydrogen-air mixture in...with a smooth growth rate of approximately 20% for each successive cell. The function y+ is a non-dimensional relationship involving the properties of

  15. Modernization of Special Monitoring of Applied Response Technologies (SMART) Technology and Methods - 2014

    Science.gov (United States)

    2014-10-01

    that the dispersants appeared to have been somewhat effective (milky emulsion observed). Heavy weather prohibited a second dispersant sortie in the...off the coast of Louisiana, experienced a catastrophic blowout, causing a major explosion , fire, and subsequent sinking of the Mobile Offshore...dispersant operations began on 22 April 2010, and continued through the final aerial dispersant application on 19 July. SMART monitoring was initially

  16. Risk-based work optimization for deep water drilling operations: Integration of risk analysis, maintenance and human factors on BOP operation

    OpenAIRE

    Liu, Honggang

    2013-01-01

    Master's thesis in Offshore technology The offshore deep water drilling has attracted global attention since the Macando blowout. It raised worldwide concern on the safety level of oil & gas industry and resulted in directly influence on offshore drilling activity. The thesis start from the introduction of offshore drilling, and the development of global oil & gas market, then come back to China, and generally described the history of offshore petroleum exploration and production in South ...

  17. 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.

  18. GWOT Vascular Injury Study 2 Supplemental Project: Impact of Prophylactic Fasciotomy

    Science.gov (United States)

    2016-10-01

    severe vascular, orthopedic/bone, nerve , or other injury . http://www.trauma.org/index.php/main/article/510/ Overall Vascular (total number...Pseudo-aneurysm, vascular blow-out, stenosis, failed vascular repair , AV fistula, and/or venous insufficiency. GWOT Vascular Injury Study...Award Number: W81XWH-14-2-0165 TITLE: GWOT Vascular Injury Study 2 Supplemental Project: Impact of Prophylactic Fasciotomy PRINCIPAL INVESTIGATOR

  19. STABILITE DE FLAMMES LAMINAIRES PARTIELLEMENT PREMELANGEES- APPLICATION AUX BRULEURS DOMESTIQUES

    OpenAIRE

    Lacour, Corine

    2006-01-01

    Phenomena responsible of partially premixed laminar flame stabilisation are investigated on a rich premixed burner configuration. The structure and aerodynamic of the flame generated by a cooking model burner are characterized by Planar Laser Induced Fluorescence of OH radical and Particle Image Velocimetry. The flame behaviour is studied from a stable reference case toward blow-out by varying the flow inlet conditions, the burner geometry and its thermal properties. The flame can be consider...

  20. 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...

  1. 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.

  2. Simulating pathways of subsurface oil in the Faroe-Shetland Channel using an ocean general circulation model.

    Science.gov (United States)

    Main, C E; Yool, A; Holliday, N P; Popova, E E; Jones, D O B; Ruhl, H A

    2017-01-15

    Little is known about the fate of subsurface hydrocarbon plumes from deep-sea oil well blowouts and their effects on processes and communities. As deepwater drilling expands in the Faroe-Shetland Channel (FSC), oil well blowouts are a possibility, and the unusual ocean circulation of this region presents challenges to understanding possible subsurface oil pathways in the event of a spill. Here, an ocean general circulation model was used with a particle tracking algorithm to assess temporal variability of the oil-plume distribution from a deep-sea oil well blowout in the FSC. The drift of particles was first tracked for one year following release. Then, ambient model temperatures were used to simulate temperature-mediated biodegradation, truncating the trajectories of particles accordingly. Release depth of the modeled subsurface plumes affected both their direction of transport and distance travelled from their release location, and there was considerable interannual variability in transport. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  3. Recurrence networks to study dynamical transitions in a turbulent combustor

    Science.gov (United States)

    Godavarthi, V.; Unni, V. R.; Gopalakrishnan, E. A.; Sujith, R. I.

    2017-06-01

    Thermoacoustic instability and lean blowout are the major challenges faced when a gas turbine combustor is operated under fuel lean conditions. The dynamics of thermoacoustic system is the result of complex nonlinear interactions between the subsystems—turbulent reactive flow and the acoustic field of the combustor. In order to study the transitions between the dynamical regimes in such a complex system, the time series corresponding to one of the dynamic variables is transformed to an ɛ-recurrence network. The topology of the recurrence network resembles the structure of the attractor representing the dynamics of the system. The transitions in the thermoacoustic system are then captured as the variation in the topological characteristics of the network. We show the presence of power law degree distribution in the recurrence networks constructed from time series acquired during the occurrence of combustion noise and during the low amplitude aperiodic oscillations prior to lean blowout. We also show the absence of power law degree distribution in the recurrence networks constructed from time series acquired during the occurrence of thermoacoustic instability and during the occurrence of intermittency. We demonstrate that the measures derived from recurrence network can be used as tools to capture the transitions in the turbulent combustor and also as early warning measures for predicting impending thermoacoustic instability and blowout.

  4. Filament Eruptions, Jets, and Space Weather

    Science.gov (United States)

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

    2013-01-01

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

  5. Drilling of a 2000-metre (6562-FT) Borehole for Geothermal Steam in Iceland

    Energy Technology Data Exchange (ETDEWEB)

    Ragnars, K.; Benediktsson, S.

    1981-01-01

    Drilling for geothermal heat has been carried out in Iceland since 1928, when hot water was obtained for district heating in Reykjavik. From that time, in particular in the sixties, extensive drilling has resulted in the annual utilization of 54 million tons of water and 2 million tons of steam. Five drilling rigs are used for geothermal drilling, with depth capacity ranging from 400 to 3,600 meters (1,312 to 11,812 feet). Drilling procedures vary extensively and depend on whether a high- or low-temperature field is being drilled, the main difference being the well-casing program and the blowout equipment used.

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

    Science.gov (United States)

    Fifrey, Priscilla

    2010-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Hadgu, T.; O' Brien, D.G.; Stoelzel, D.M.; Vaughn, P.

    1998-10-15

    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. Thereforq 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 to the surface.

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

    International Nuclear Information System (INIS)

    Tanitame, Keizo; Kaichi, Yoko; Nakamura, Yuko

    2013-01-01

    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. 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.

  10. The natural gas market

    International Nuclear Information System (INIS)

    Lagrasta, F.; Kaminski, V.; Prevatt, R.

    1999-01-01

    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

  11. Experiences with sol-gel bonded high porosity alumina fiber materials for filter applications

    OpenAIRE

    Handrick, Karin E.; Mohlratzer, August; Ostertag, Rolf; Sporn, Dieter; Schmidt, Helmut K.

    1988-01-01

    High porous alumina fiber structures appear promising for hot gas filtration in particular for diesel particulate traps. For this purpose, however, a method is required for manufacturing of stable shapes resisant to the blow-out by the gas flow. The sol-gel process was expected to be the best suited method for fiber bonding to provide the required stability. The main tasks of the development-work were a uniform isotropic fiber-distribution, the adaptation of the sol-gel-process to the applica...

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

    CERN Document Server

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

    2004-01-01

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

  13. Fire safety engineering

    International Nuclear Information System (INIS)

    Smith, D.N.

    1989-01-01

    The periodic occurrence of large-scale, potentially disastrous industrial accidents involving fire in hazardous environments such as oilwell blowouts, petrochemical explosions and nuclear installations highlights the need for an integrated approach to fire safety engineering. Risk reduction 'by design' and rapid response are of equal importance in the saving of life and property in such situations. This volume of papers covers the subject thoroughly, touching on such topics as hazard analysis, safety design and testing, fire detection and control, and includes studies of fire hazard in the context of environment protection. (author)

  14. Dual-Mode Scramjet Flameholding Operability Measurements

    Science.gov (United States)

    Donohue, James M.

    2012-01-01

    Flameholding measurements were made in two different direct connect combustor facilities that were designed to simulate a cavity flameholder in the flowfield of a hydrocarbon fueled dual-mode scramjet combustor. The presence of a shocktrain upstream of the flameholder has a significant impact on the inlet flow to the combustor and on the flameholding limits. A throttle was installed in the downstream end of the test rigs to provide the needed back-pressurization and decouple the operation of the flameholder from the backpressure formed by heat release and thermal choking, as in a flight engine. Measurements were made primarily with ethylene fuel but a limited number of tests were also performed with heated gaseous JP-7 fuel injection. The flameholding limits were measured by ramping inlet air temperature down until blowout was observed. The tests performed in the United Technologies Research Center (UTRC) facility used a hydrogen fueled vitiated air heater, Mach 2.2 and 3.3 inlet nozzles, a scramjet combustor rig with a 1.666 by 6 inch inlet and a 0.65 inch deep cavity. Mean blowout temperature measured at the baseline condition with ethylene fuel, the Mach 2.2 inlet and a cavity pressure of 21 psia was 1502 oR. Flameholding sensitivity to a variety of parameters was assessed. Blowout temperature was found to be most sensitive to fuel injection location and fuel flowrates and surprisingly insensitive to operating pressure (by varying both back-pressurization and inlet flowrate) and inlet Mach number. Video imaging through both the bottom and side wall windows was collected simultaneously and showed that the flame structure was quite unsteady with significant lateral movements as well as movement upstream of the flameholder. Experiments in the University of Virginia (UVa) test facility used a Mach 2 inlet nozzle with a 1 inch by 1.5 inch exit cross section, an aspect ratio of 1.5 versus 3.6 in the UTRC facility. The UVa facility tests were designed to measure the

  15. Communications systems and methods for subsea processors

    Science.gov (United States)

    Gutierrez, Jose; Pereira, Luis

    2016-04-26

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

  16. 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.

  17. 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.

  18. The usefulness of target CT in orbital, sellar, and parasellar lesions

    International Nuclear Information System (INIS)

    Hoshiko, Naomi; Fukui, Kotaro; Takahashi, Mutsumasa; Miyao, Masayuki.

    1986-01-01

    Fifty-four cases of orbital, sellar, parasellar, and paranasal lesions were examined by means of target CT. Transverse and coronal target CT was superior to conventional CT in the visualization of small anatomic structures, such as optic canals, orbital walls, and paranasal sinuses. Transverse target CT was more effective than conventional CT in demonstrating orbital lesions, such as mucoceles, meningiomas, and ethmoid osteoblastoma. Coronal target CT was more effective than conventional CT in demonstrating blow-out fractures, mucoceles, and aneurysms. In general, target CT was superior to plain radiography conventional tomography and conventional CT in the demonstration of orbital-wall fractures and the invasion of paranasal sinuses. (author)

  19. The LLNL/UCLA high gradient inverse free electron laser

    Energy Technology Data Exchange (ETDEWEB)

    Moody, J. T.; Musumeci, P.; Anderson, G.; Anderson, S.; Betts, S.; Fisher, S.; Gibson, D.; Tremaine, A.; Wu, S. [Department of Physics and Astronomy, UCLA, Los Angeles California, 90095 (United States); Lawrence Livermore National Laboratory (United States)

    2012-12-21

    We describe the Inverse Free Electron Accelerator currently under construction at Lawrence Livermore National Lab. Upon completion of this accelerator, high brightness electrons generated in the photoinjector blowout regime and accelerated to 50 MeV by S-band accelerating sections will interact with > 4 TW peak power Ti:Sapphire laser in a highly tapered 50 cm undulator and experience an acceleration gradient of > 200 MeV/m. We present the final design of the accelerator as well as the results of start-to-end simulations investigating preservation of beam quality and tolerances involved with this accelerator.

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

    Directory of Open Access Journals (Sweden)

    G. Wittig

    2015-08-01

    Full Text Available 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.

  1. 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.

  2. Efficiency Versus Instability in Plasma Accelerators

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-01-05

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-10-27

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

  5. Methane Flux to the Atmosphere from the Deepwater Horizon Oil Leak

    Science.gov (United States)

    Yvon-Lewis, S. A.; Hu, L.; Kessler, J. D.; Garcia Tigreros, F.; Chan, E. W.; Du, M.

    2010-12-01

    The unfortunate blowout at the BP Deepwater Horizon (DWH) oil rig on April 20, which killed 11 people, was releasing oil and methane at an average rate of 58,000 barrels per day into the deep ocean, until it was recently capped resulting in a total of 4.9 million barrels released (National Incident Command Report, 2010). The methane component of the emission was estimated at 40-60%. As part of a NSF funded RAPID award, the sea-to-air flux of methane from the blowout at the Deepwater Horizon was measured on board the R/V Cape Hatteras from June 11-20 with substantial spatial and temporal resolution over the course of seven days in June 2010. Air and water concentrations were analyzed continuously from a flowing air line and a continuously flowing seawater equilibrator using cavity ring-down spectrometers (CRDS) and a gas chromatograph with a flame ionization detector (GC-FID). The results indicate a low flux of methane to the atmosphere (0.024 μmol m^{-2} d^{-1}) with atmospheric and seawater equilibrium mixing ratios averaging 1.86 ppm and 2.85 ppm, respectively within the survey area. Most of the methane emitted from the wellhead was not emitted to the atmosphere. It dissolved into the water column at depth.

  6. Partial Photochemical Oxidation Was a Dominant Fate of Deepwater Horizon Surface Oil.

    Science.gov (United States)

    Ward, Collin P; Sharpless, Charles M; Valentine, David L; French-McCay, Deborah P; Aeppli, Christoph; White, Helen K; Rodgers, Ryan P; Gosselin, Kelsey M; Nelson, Robert K; Reddy, Christopher M

    2018-02-20

    Following the Deepwater Horizon (DWH) blowout in 2010, oil floated on the Gulf of Mexico for over 100 days. In the aftermath of the blowout, substantial accumulation of partially oxidized surface oil was reported, but the pathways that formed these oxidized residues are poorly constrained. Here we provide five quantitative lines of evidence demonstrating that oxidation by sunlight largely accounts for the partially oxidized surface oil. First, residence time on the sunlit sea surface, where photochemical reactions occur, was the strongest predictor of partial oxidation. Second, two-thirds of the partial oxidation from 2010 to 2016 occurred in less than 10 days on the sunlit sea surface, prior to coastal deposition. Third, multiple diagnostic biodegradation indices, including octadecane to phytane, suggest that partial oxidation of oil on the sunlit sea surface was largely driven by an abiotic process. Fourth, in the laboratory, the dominant photochemical oxidation pathway of DWH oil was partial oxidation to oxygenated residues rather than complete oxidation to CO 2 . Fifth, estimates of partial photo-oxidation calculated with photochemical rate modeling overlap with observed oxidation. We suggest that photo-oxidation of surface oil has fundamental implications for the response approach, damage assessment, and ecosystem restoration in the aftermath of an oil spill, and that oil fate models for the DWH spill should be modified to accurately reflect the role of sunlight.

  7. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Tomita, Kazumi; Ogura, Yuuko; Takeshita, Gen; Koga, Sukehiko (Fujita Health Univ., Toyoake, Aichi (Japan). School of Medicine); Katada, Kazuhiro; Anno, Hirofumi

    1993-10-01

    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).

  9. Relationship between Metabolic Syndrome and Ocular Microcirculation Shown by Laser Speckle Flowgraphy in a Hospital Setting Devoted to Sleep Apnea Syndrome Diagnostics

    Directory of Open Access Journals (Sweden)

    Tomoaki Shiba

    2017-01-01

    Full Text Available Purpose. To clarify whether the incidence of metabolic syndrome (MetS and the overlap of MetS components are affecting the ocular circulation shown by laser speckle flowgraphy (LSFG. Materials and Methods. We studied 76 consistent patients. Blowout score (BOS and blowout time (BOT, which are the pulse waveform analysis parameters, and mean blur rate (MBR using LSFG in the optic nerve head (ONH and choroid were evaluated. Throughout, the ONH was separated out from the vessels and tissue for analysis and MBRs in the ONH were divided into four sections (superior, temporal, inferior, and nasal. Results. Thirty-two patients were diagnosed having Mets. MBR-Tissue (P=0.003, MBR-All (P=0.01, MBR-Choroid (P=0.04, and BOS-Choroid (P=0.03 were significantly lower in patients with MetS than in the patients without MetS. Multiple-regression analysis revealed the temporal side of MBR-Tissue and BOS-Choroid which were identified as factors contributing independently to the overlap of the MetS components. Multiple-regression analysis also revealed that the MetS components were identified to be factors independently contributing to the BOS-Choroid and temporal side of MBR-Tissue. Conclusion. Our study clarified that the incidence of MetS and the overlap of the MetS components are significantly affecting the ONH and choroidal microcirculation.

  10. The Complex Neutral Gas Dynamics of the Dwarf Starburst Galaxy NGC 625

    Science.gov (United States)

    Cannon, John M.; McClure-Griffiths, N. M.; Skillman, Evan D.; Côté, Stéphanie

    2004-05-01

    We present new multiconfiguration H I aperture synthesis imaging of the nearby dwarf starburst galaxy NGC 625 obtained with the Australia Telescope Compact Array. Total H I column density images show gas well aligned with the optical major axis and low column density H I extending to greater than 6 optical scale lengths. The H I velocity field, on the other hand, is highly disturbed, with neutral gas at nearly all detected velocities within the central region. After considering various interpretations, we find that a blowout scenario most accurately describes the data. Since at our resolution we do not detect any large evacuated holes in the H I disk, we interpret this blowout to be the result of the extended (both spatially and temporally) star formation event that NGC 625 has undergone in the last 100 Myr. This is one of the clearest examples of H I outflow detected in a dwarf galaxy. We find no obvious external trigger for this extended star formation event. We detect strong radio continuum emission from the largest H II regions; comparing to our Hubble Space Telescope and ground-based Hα fluxes suggests either appreciable amounts of extinction toward the star formation regions or the contribution of nonthermal sources to the radio continuum luminosity.

  11. Development Application - Terra Nova Development - Environmental Impact Statement

    International Nuclear Information System (INIS)

    1996-01-01

    This environmental impact statement is one of the five main parts of the application for approval for developing the Terra Nova Field off the coast of Newfoundland. The application was prepared and submitted by Petro-Canada on behalf of and in cooperation with its co-proponents. The Statement provides a description of the project, details of the proposed environmental management of the development, the physical and biological environmental setting, the impact that the development is likely to have on the environment, details of the environmental protection plans, mitigation measures and contingency plans, and the proposed monitoring and reporting plans. There are a number of appendices containing historical statistics on blowouts (App. A), a comparison of the Terra Nova Development and operations in the Gulf of Mexico (App. B), statistics on blowout-related spills and Canadian experiences (App. C), a summary of qualitative effects of accidental events in offshore production and transportation activities (App. D), and a brief description of the S. L. Ross Oil Spill Model (App. E). There is also a glossary of terms and an extensive bibliography of several hundred items

  12. State of the Arctic Environment

    International Nuclear Information System (INIS)

    1990-01-01

    The Arctic environment, covering about 21 million km 2 , 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

  13. 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.

  14. Study on the Effect of Air Throttling on Flame Stabilization of an Ethylene Fueled Scramjet Combustor

    Directory of Open Access Journals (Sweden)

    Ye Tian

    2015-01-01

    Full Text Available The effect of air throttling on flame stabilization of an ethylene fueled scramjet combustor was investigated by numerical simulation and experiments in this paper. The results were obtained under the inflow condition with Mach number of 2.0, total temperature of 900 K, total pressure of 0.8 MPa, and total equivalence ratio of 0.5. The shock train generated by air throttling had a big effect on the flow structure of the scramjet combustor. Compared with the combustor without air throttling, the flow field with air throttling had a lower velocity and higher pressure, temperature, and vortices intensity. Air throttling was an effective way to achieve flame stabilization; the combustion in the combustor without air throttling was nearly blowout. In the experiment, the combustion was nearly blowout with air throttling location of 745 mm, and the fuel/air mixture in the combustor with air throttling location of 875 mm was burned intensively. It was important to choose the location and time sequence of air throttling for fuel ignition and flame stabilization. The numerical simulation results agreed well with experimental measurements.

  15. 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.

  16. Efficiency versus instability in plasma accelerators

    Science.gov (United States)

    Lebedev, Valeri; Burov, Alexey; Nagaitsev, Sergei

    2017-12-01

    Plasma wakefield acceleration is one of the main technologies being developed for future high-energy colliders. Potentially, it can create a cost-effective path to the highest possible energies for e+e- or γ -γ colliders and produce a profound effect on the developments for high-energy physics. Acceleration in a blowout regime, where all plasma electrons are swept away from the axis, is presently considered to be the primary choice for beam acceleration. In this paper, we derive a universal efficiency-instability relation, between the power efficiency and the key instability parameter of the trailing bunch for beam acceleration in the blowout regime. We also show that the suppression of instability in the trailing bunch can be achieved through Balakin-Novokhatsky-Smirnov damping by the introduction of a beam energy variation along the bunch. Unfortunately, in the high-efficiency regime, the required energy variation is quite high and is not presently compatible with collider-quality beams. We would like to stress that the development of the instability imposes a fundamental limitation on the acceleration efficiency, and it is unclear how it could be overcome for high-luminosity linear colliders. With minor modifications, the considered limitation on the power efficiency is applicable to other types of acceleration.

  17. Important role of vertical migration of compressed gas, oil and water in formation of AVPD (abnormally high pressure gradient) zones

    Energy Technology Data Exchange (ETDEWEB)

    Anikiyev, K.A.

    1980-01-01

    The principal role of vertical migration of compressed gases, gas-saturated petroleum and water during formation of abnormally high pressure gradients (AVPD) is confirmed by extensive factual data on gas production, grifons, blowouts and gushers that accompany drilling formations with AVPD from early history to the present time; the sources of vertical migration of compressed fluids, in accordance with geodynamic AVPD theory, are the deep degasified centers of the earth mantle. Among the various types of AVPD zones especially notable are the large (often massive or massive-layer) deposits and the intrusion aureoles that top them in the overlapping covering layers. Prediction of AVPD zones and determining their field and energy potential must be based on field-baric simulation of the formations being drilled in light of laws regarding the important role of the vertical migration of compressed fluids. When developing field-baric models, it is necessary to utilize the extensive and valuable data on grifons, gas production and blowouts that has been collected and categorized by drilling engineers and production geologists. To further develop data on field-baric conditions of the earth, it is necessary to collect and study signals of AVPD. First of all, there is a need to evaluate potential elastic resources of compressed fluids which can move from the bed into the well. Thus it is necessary to study and standardize intrusion aureoles and other AVPD zones within the aspect of fieldbaric modeling.

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

    CERN Document Server

    2017-01-01

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

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

    International Nuclear Information System (INIS)

    Smith, M.

    2009-01-01

    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.

  20. 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.

  1. Draining and drying process development of the Tokamak Cooling Water System of ITER

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seokho, E-mail: kims@ornl.gov [US ITER, Oak Ridge National Laboratory, Oak Ridge, TN (United States); Van Hove, Walter; Ferrada, Juan [US ITER, Oak Ridge National Laboratory, Oak Ridge, TN (United States); Di Maio, Pietro Alessandro [University of Palermo, Viale delle Scienze, Palermo 90128 (Italy); Felde, David [Reactor and Nuclear Systems Division, ORNL, Oak Ridge, TN (United States); Raphael, Mitteau; Dell’Orco, Giovanni [ITER Organization, 13067 St Paul Lez Durance (France); Berry, Jan [US ITER, Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    2016-11-01

    Highlights: • A thermal-hydraulic model using RELAP was developed for the ITER FW/BLK modules to determine design parameters for the nitrogen blowout flow rate and pressure. • The analysis indicates that as low as 2 MPa of pressure difference over the blanket modules will sufficiently evacuate the water in blankets. • A limited validation study indicates that the analysis yields less conservative results to compare against data collected from experiments. Therefore, the designed blow out flow of the drying system was selected with a large margin above the measured values to ensure the blow out operation. - Abstract: The ITER Organization (IO) developed a thermal-hydraulic (TH) model of the complex first wall and blanket (FW/BLK) cooling channels to determine gas flow rate and pressure required to effectively blow out the water in the FW/BLK. In addition, US ITER conducted experiments for selected geometries of FW/BLK flow channels to predict the blowout parameters. The analysis indicates that as low as 2 MPa of pressure difference over the blanket modules will ensure substantial evacuation of the water in blankets with just a few percent remaining in the blanket flow channels. A limited validation study indicates that the analysis yields less conservative results to compare against data collected from experiments. Therefore, the designed blow out flow of the drying system was selected with a large margin above the measured values to ensure the blow out operation.

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

    Science.gov (United States)

    Blust, James W.

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

  3. Robust active combustion control for the optimization of environmental performance and energy efficiency

    Science.gov (United States)

    Demayo, Trevor Nat

    Criteria pollutant regulations, climate change concerns, and energy conservation efforts are placing strict constraints in the design and operation of advanced, stationary combustion systems. To ensure minimal pollutant emissions and maximal efficiency at every instant of operation while preventing reaction blowout, combustion systems need to react and adapt in real-time to external changes. This study describes the development, demonstration, and evaluation of a multivariable feedback control system, designed to maximize the performance of natural gas-fired combustion systems. A feedback sensor array was developed to monitor reaction stability and measure combustion performance as a function of NOx, CO, and O, emissions. Acoustic and UV chemiluminescent emissions were investigated for use as stability indicators. Modulated signals of CH* and CO2* chemiluminescence were found to correlate well with the onset of lean blowout. A variety of emissions sensors were tested and evaluated, including conventional CEMS', micro-fuel cells, a zirconia NOx transducer, and a rapid response predictive NOx sensor based on UV flame chemiluminescence. A dual time-scale controller was designed to actively optimize operating conditions by maximizing a multivariable performance function J using a linear direction set search algorithm. The controller evaluated J under slow, quasi steady-state conditions, while dynamically monitoring the reaction zone at high speed for pre-blowout instabilities or boundary condition violations. To establish the input control parameters, two burner systems were selected: a 30 kW air-swirl, generic research burner, and a 120 kW scaled, fuel-staged, industrial boiler burner. The parameters, chosen to most affect burner performance, consisted of air swirl intensity and excess air for the generic burner, and fuel-staging and excess air for the boiler burner. A set of optimization parameters was also established to ensure efficient and deterministic

  4. Enceladus' near-surface CO2 gas pockets and surface frost deposits

    Science.gov (United States)

    Matson, Dennis L.; Davies, Ashley Gerard; Johnson, Torrence V.; Combe, Jean-Philippe; McCord, Thomas B.; Radebaugh, Jani; Singh, Sandeep

    2018-03-01

    Solid CO2 surface deposits were reported in Enceladus' South Polar Region by Brown et al. (2006). They noted that such volatile deposits are temporary and posited ongoing replenishment. We present a model for this replenishment by expanding on the Matson et al. (2012) model of subsurface heat and chemical transport in Enceladus. Our model explains the distributions of both CO2 frost and complexed CO2 clathrate hydrate as seen in the Cassini Visual and Infrared Mapping Spectrometer (VIMS) data. We trace the journey of CO2 from a subsurface ocean. The ocean-water circulation model of Matson et al. (2012) brings water up to near the surface where gas exsolves to form bubbles. Some of the CO2 bubbles are trapped and form pockets of gas in recesses at the bottom of the uppermost ice layer. When fissures break open these pockets, the CO2 gas is vented. Gas pocket venting is episodic compared to the more or less continuous eruptive plumes, emanating from the "tiger stripes", that are supported by plume chambers. Two styles of gas pocket venting are considered: (1) seeps, and (2) blowouts. The presence of CO2 frost patches suggests that the pocket gas slowly seeped through fractured, cold ice and when some of the gas reached the surface it was cold enough to condense (i.e., T ∼70 to ∼119 K). If the fissure opening is large, a blowout occurs. The rapid escape of gas and drop in pocket pressure causes water in the pocket to boil and create many small aerosol droplets of seawater. These may be carried along by the erupting gas. Electrically charged droplets can couple to the magnetosphere, and be dragged away from Enceladus. Most of the CO2 blowout gas escapes from Enceladus and the remainder is distributed globally. However, CO2 trapped in a clathrate structure does not escape. It is much heavier and slower moving than the CO2 gas. Its motion is ballistic and has an average range of about 17 km. Thus, it contributes to deposits in the vicinity of the vent. Local heat

  5. Rotating preventers

    International Nuclear Information System (INIS)

    Tangedahl, M.J.; Stone, C.R.

    1992-01-01

    This paper reports that recent changes in the oil and gas industry and ongoing developments in horizontal and underbalanced drilling necessitated development of a better rotating head. A new device called the rotating blowout preventer (RBOP) was developed by Seal-Tech. It is designed to replace the conventional rotating control head on top of BOP stacks and allows drilling operations to continue even on live (underbalanced) wells. Its low wear characteristics and high working pressure (1,500 psi) allow drilling rig crews to drill safely in slightly underbalanced conditions or handle severe well control problems during the time required to actuate other BOPs in the stack. Drilling with a RBOP allows wellbores to be completely closed in tat the drill floor rather than open as with conventional BOPs

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

    CERN Document Server

    Thomas, Johannes

    2016-01-01

    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.

  7. Encroachment of oriental bittersweet into Pitcher’s thistle habitat

    Science.gov (United States)

    Leicht-Young, Stacey A.; Pavlovic, Noel B.

    2012-01-01

    Common invasive species and rare endemic species can grow and interact at the ecotone between forested and non-forested dune habitats. To investigate these interactions, a comparison of the proximity and community associates of a sympatric invasive (Celastrus orbiculatus; oriental bittersweet) and native (C. scandens; American bittersweet) liana species to federally threatened Cirsium pitcheri (Pitcher's thistle) in the dunes habitats of Lake Michigan was conducted. Overall, the density of the invasive liana species was significantly greater in proximity to C. pitcheri than the native species. On the basis of composition, the three focal species occurred in both foredune and blowout habitats. The plant communities associated with the three focal species overlapped in ordination space, but there were significant differences in composition. The ability of C. orbiculatus to rapidly grow and change the ecological dynamics of invasion sites adds an additional threat to the successional habitats of C. pitcheri.

  8. Erosion dynamics of powder snow avalanches - model of frontal entrainment

    Science.gov (United States)

    Louge, Michel; Sovilla, Betty

    2013-04-01

    We analyze entrainment at the head of powder snow avalanches (PSA) behaving as an eruption current. Instead of invoking an erosion model or other fitted parameters, the analysis assumes that erosion is sustained by a massive blow-out arising as the snow cover is fluidized by the very pore pressure gradients that the avalanche induces within the snow pack. The stability of a mass balance involving snow cover and flow in the PSA's head region then sets frontal speed, height, mixed-mean density, snowpack fluidization depth, frontal impact pressure and static pressure. We show that acceleration of the front is insensitive to local slope, but effectively depends on the rate of change in cloud width. We compare predictions with data collected at the Vallee de la Sionne.

  9. Methane flux to the atmosphere from the Deepwater Horizon oil disaster

    Science.gov (United States)

    Yvon-Lewis, Shari A.; Hu, Lei; Kessler, John

    2011-01-01

    The sea-to-air flux of methane from the blowout at the Deepwater Horizon was measured with substantial spatial and temporal resolution over the course of seven days in June 2010. Air and water concentrations were analyzed continuously from a flowing air line and a continuously flowing seawater equilibrator using cavity ring-down spectrometers (CRDS) and a gas chromatograph with a flame ionization detector (GC-FID). The results indicate a low flux of methane to the atmosphere (0.024 μmol m-2 d-1) with atmospheric and seawater equilibrium mixing ratios averaging 1.86 ppm and 2.85 ppm, respectively within the survey area. The oil leak, which was estimated to contain 30.2% methane by weight, was not a significant source of methane to the atmosphere during this study. Most of the methane emitted from the wellhead was dissolved in the deep ocean.

  10. Airflow over part of the Southern High Plains interpreted from LANDSAT imagery

    Energy Technology Data Exchange (ETDEWEB)

    Carlisle, J. W.; Marrs, R. W.

    1978-07-01

    An interpretation of eolian features, using remote sensing techniques, for part of the Southern High Plains demonstrates the use of remote sensing as an inexpensive and easily applicable tool to assess wind-energy potential. The most useful eolian features in such an interpretation are sand dunes, blowouts, dust plumes, clay dunes, playa plumes, and playa orientation. Although the relief is low to moderate in this area, topographic channeling is the most important factor in determining high wind-energy areas. Interpretation of eolian features detectable on LANDSAT imagery provided information for a regional assessment of wind-energy potential in the Southern High Plains. A map was compiled summarizing the interpretation and the wind-energy information.

  11. 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...

  12. Nonlinear dynamics in a Cournot duopoly with relative profit delegation

    International Nuclear Information System (INIS)

    Fanti, Luciano; Gori, Luca; Sodini, Mauro

    2012-01-01

    This paper analyses the dynamics of a nonlinear Cournot duopoly with managerial delegation and homogeneous players. We assume that the owners of both firms hire a manager and delegate output decisions to him or her. Each manager receives a fixed salary plus a bonus based on relative (profit) performance. Managers of both firms may collude or compete. In cases of both collusion and a low degree of competition, we find that synchronised dynamics take place. However, when the degree of competition is high, the dynamics may undergo symmetry-breaking bifurcations, which can cause significant global phenomena. Specifically, there is on–off intermittency and blow-out bifurcations for several parameter values. In addition, several attractors may coexist. The global behaviour of the noninvertible map is investigated through studying a transverse Lyapunov exponent and the folding action of the critical curves of the map. These phenomena are impossible under profit maximisation.

  13. 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.

  14. Laser dynamics in transversely inhomogeneous plasma and its relevance to wakefield acceleration

    Science.gov (United States)

    Pathak, V. B.; Vieira, J.; Silva, L. O.; Nam, Chang Hee

    2018-05-01

    We present full set of coupled equations describing the weakly relativistic dynamics of a laser in a plasma with transverse inhomogeneity. We apply variational principle approach to obtain these coupled equations governing laser spot-size, transverse wavenumber, curvature, transverse centroid, etc. We observe that such plasma inhomogeneity can lead to stronger self-focusing. We further discuss the guiding conditions of laser in parabolic plasma channels. With the help of multi-dimensional particle in cell simulations the study is extended to the blowout regime of laser wakefield acceleration to show laser as well as self-injected electron bunch steering in plasma to generate unconventional particle trajectories. Our simulation results demonstrate that such transverse inhomogeneities due to asymmetric self focusing lead to asymmetric bubble excitation, thus inducing off-axis self-injection.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-07-01

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

  16. Electron Acceleration in Wakefield and Supra-Bubble Regimes by Ultraintense Laser with Asymmetric Pulse

    International Nuclear Information System (INIS)

    Maimaitiaili, Bake; Sayipjamal, Dulat; Aimierding, Aimidula; Xie Baisong

    2011-01-01

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

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

    International Nuclear Information System (INIS)

    Bachman, G.O.

    1985-07-01

    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

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

    Science.gov (United States)

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

    2012-01-01

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

  19. Stable, tunable, quasimonoenergetic electron beams produced in a laser wakefield near the threshold for self-injection

    Directory of Open Access Journals (Sweden)

    S. Banerjee

    2013-03-01

    Full Text Available Stable operation of a laser-plasma accelerator near the threshold for electron self-injection in the blowout regime has been demonstrated with 25–60 TW, 30 fs laser pulses focused into a 3–4 millimeter length gas jet. Nearly Gaussian shape and high nanosecond contrast of the focused pulse appear to be critically important for controllable, tunable generation of 250–430 MeV electron bunches with a low-energy spread, ∼10  pC charge, a few-mrad divergence and pointing stability, and a vanishingly small low-energy background. The physical nature of the near-threshold behavior is examined using three-dimensional particle-in-cell simulations. Simulations indicate that properly locating the nonlinear focus of the laser pulse within the plasma suppresses continuous injection, thus reducing the low-energy tail of the electron beam.

  20. 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.

  1. 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.

  2. Flame Dynamics inside Rectangular Meso scale Channels

    Science.gov (United States)

    Anwar, Muzammil; Naseer Mohammad, Abdul; Mohammad, Akram; Juhany, Khalid A.

    2018-03-01

    The present work is focused on the experimental study of flame dynamics in preheated meso-scale straight channels of various aspect ratios (2, 5, 12 and 15) and inlet dimensions.Premixed methane-air mixture were used for the reported experiments. To maintain a positive wall temperature gradient inside the channel, the lower part of the rectangular channels were heated at a constant temperature using an external electric heater. Laminar premixed flames were stabilized inside these channels. Various flame propagation modes such as concave, planar, and convex flames with respect to unburned mixture. Concave flames lead to flashback whereas convex flames lead to blowout. Increase in aspect ratio and decrease of flow velocity leads to flame flashback.

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

    Energy Technology Data Exchange (ETDEWEB)

    Bachman, G.O.

    1985-07-01

    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.

  4. Measurements of the critical power for self-injection of electrons in a laser wakefield accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Froula, D H; Clayton, C E; Doppner, T; Fonseca, R A; Marsh, K A; Barty, C J; Divol, L; Glenzer, S H; Joshi, C; Lu, W; Martins, S F; Michel, P; Mori, W; Palastro, J P; Pollock, B B; Pak, A; Ralph, J E; Ross, J S; Siders, C; Silva, L O; Wang, T

    2009-06-02

    A laser wakefield acceleration study has been performed in the matched, self-guided, blow-out regime where a 10 J, 60 fs laser produced 720 {+-} 50 MeV quasi-monoenergetic electrons with a divergence of {Delta}{theta} = 2.85 {+-} 0.15 mRad. While maintaining a nearly constant plasma density (3 x 10{sup 18} cm{sup -3}), a linear electron energy gain was measured from 100 MeV to 700 MeV when the plasma length was scaled from 3 mm to 8 mm. Absolute charge measurements indicate that self-injection occurs when P/P{sub cr} > 4 and saturates around 100 pC for P/P{sub cr} > 12. The results are compared with both analytical scalings and full 3D particle-in-cell simulations.

  5. Natural and Unnatural Oil Layers on the Surface of the Gulf of Mexico Detected and Quantified in Synthetic Aperture RADAR Images with Texture Classifying Neural Network Algorithms

    Science.gov (United States)

    MacDonald, I. R.; Garcia-Pineda, O. G.; Morey, S. L.; Huffer, F.

    2011-12-01

    Effervescent hydrocarbons rise naturally from hydrocarbon seeps in the Gulf of Mexico and reach the ocean surface. This oil forms thin (~0.1 μm) layers that enhance specular reflectivity and have been widely used to quantify the abundance and distribution of natural seeps using synthetic aperture radar (SAR). An analogous process occurred at a vastly greater scale for oil and gas discharged from BP's Macondo well blowout. SAR data allow direct comparison of the areas of the ocean surface covered by oil from natural sources and the discharge. We used a texture classifying neural network algorithm to quantify the areas of naturally occurring oil-covered water in 176 SAR image collections from the Gulf of Mexico obtained between May 1997 and November 2007, prior to the blowout. Separately we also analyzed 36 SAR images collections obtained between 26 April and 30 July, 2010 while the discharged oil was visible in the Gulf of Mexico. For the naturally occurring oil, we removed pollution events and transient oceanographic effects by including only the reflectance anomalies that that recurred in the same locality over multiple images. We measured the area of oil layers in a grid of 10x10 km cells covering the entire Gulf of Mexico. Floating oil layers were observed in only a fraction of the total Gulf area amounting to 1.22x10^5 km^2. In a bootstrap sample of 2000 replications, the combined average area of these layers was 7.80x10^2 km^2 (sd 86.03). For a regional comparison, we divided the Gulf of Mexico into four quadrates along 90° W longitude, and 25° N latitude. The NE quadrate, where the BP discharge occurred, received on average 7.0% of the total natural seepage in the Gulf of Mexico (5.24 x10^2 km^2, sd 21.99); the NW quadrate received on average 68.0% of this total (5.30 x10^2 km^2, sd 69.67). The BP blowout occurred in the NE quadrate of the Gulf of Mexico; discharged oil that reached the surface drifted over a large area north of 25° N. Performing a

  6. Fallacies of composition in nonlinear marketing models

    Science.gov (United States)

    Bischi, Gian Italo; Cerboni Baiardi, Lorenzo

    2015-01-01

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

  7. Experimental signatures of direct-laser-acceleration-assisted laser wakefield acceleration

    Science.gov (United States)

    Shaw, J. L.; Lemos, N.; Marsh, K. A.; Froula, D. H.; Joshi, C.

    2018-04-01

    The direct laser acceleration (DLA) of electrons in a laser wakefield accelerator (LWFA) operating in the forced or quasi-blowout regimes has been investigated through experiment and simulation. When there is a significant overlap between the trapped electrons and the drive laser in a LWFA cavity, the resulting electrons can gain energy from both the LWFA and the DLA mechanisms. Experimental work investigates the properties of the electron beams produced in a LWFA with ionization injection by dispersing those beams in the direction perpendicular to the laser polarization. These electron beams show certain spectral features that are characteristic of DLA. These characteristic features are reproduced using particle-in-cell simulations, where particle tracking was used to elucidate the roles of LWFA and DLA to the energy gain of the electrons in this experimental regime and to demonstrate that such spectral features are definitive signatures of the presence of DLA in LWFA.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-09-01

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

  9. Simulação composicional de controle de poços

    OpenAIRE

    Claudio Henrique de Oliveira Loiola

    2015-01-01

    Resumo: A segurança operacional durante a perfuração de um poço de hidrocarbonetos é essencial e a prevenção de um blowout é um tema muito importante na indústria do petróleo e gás natural. Sabendo-se que a detecção de um kick é feita através da observação do nível dos tanques de retorno e vazão de retorno do fluido de perfuração, a crescente utilização de fluidos de perfuração de base sintética requer um melhor entendimento da interação do gás da formação com a base sintética, considerando-s...

  10. Time varying voltage combustion control and diagnostics sensor

    Science.gov (United States)

    Chorpening, Benjamin T [Morgantown, WV; Thornton, Jimmy D [Morgantown, WV; Huckaby, E David [Morgantown, WV; Fincham, William [Fairmont, WV

    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.

  11. How Quasar Feedback May Shape the Co-evolutionary Paths

    Energy Technology Data Exchange (ETDEWEB)

    Ishibashi, Wako, E-mail: wako.ishibashi@physik.uzh.ch [Physik-Institut, University of Zurich, Zürich (Switzerland)

    2017-10-17

    Observations point toward some form of “co-evolutionary sequence,” from dust-enshrouded starbursts to luminous unobscured quasars. Active galactic nucleus (AGN) feedback is generally invoked to expel the obscuring dusty gas in a blow-out event, eventually revealing the hidden central quasar. However, the physical mechanism driving AGN feedback, either due to winds or radiation, remains uncertain and is still a source of much debate. We consider quasar feedback, based on radiation pressure on dust, which directly acts on the obscuring dusty gas. We show that AGN radiative feedback is capable of efficiently removing the obscuring cocoon, and driving powerful outflows on galactic scales, consistent with recent observations. I will discuss how such quasar feedback may provide a natural physical interpretation of the observed evolutionary path, and the physical implications in the broader context of black hole-host galaxy co-evolution.

  12. Macondo oil in northern Gulf of Mexico waters - Part 2: Dispersant-accelerated PAH dissolution in the Deepwater Horizon plume.

    Science.gov (United States)

    Driskell, William B; Payne, James R

    2018-03-11

    During the Deepwater Horizon blowout, unprecedented volumes of dispersant were applied both on the surface and at depth. Application at depth was intended to disperse the oil into smaller microdroplets that would increase biodegradation and also reduce the volumes buoyantly rising to the surface, thereby reducing surface exposures, recovery efforts, and potential stranding. In forensically examining 5300 offshore water samples for the Natural Resource Damage Assessment (NRDA) effort, profiles of deep-plume oil droplets (from filtered water samples) were compared with those also containing dispersant indicators to reveal a previously hypothesized but undocumented, accelerated dissolution of the polycyclic aromatic hydrocarbons (PAH) in the plume samples. We interpret these data in a fate-and-transport context and conclude that dispersant applications were functionally effective at depth. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. HERSCHEL -RESOLVED OUTER BELTS OF TWO-BELT DEBRIS DISKS—EVIDENCE OF ICY GRAINS

    Energy Technology Data Exchange (ETDEWEB)

    Morales, F. Y.; Bryden, G.; Werner, M. W.; Stapelfeldt, K. R., E-mail: Farisa@jpl.nasa.gov [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)

    2016-11-01

    We present dual-band Herschel /PACS imaging for 59 main-sequence stars with known warm dust ( T {sub warm} ∼ 200 K), characterized by Spitzer . Of 57 debris disks detected at Herschel wavelengths (70 and/or 100 and 160 μ m), about half have spectral energy distributions (SEDs) that suggest two-ring disk architectures mirroring that of the asteroid–Kuiper Belt geometry; the rest are consistent with single belts of warm, asteroidal material. Herschel observations spatially resolve the outer/cold dust component around 14 A-type and 4 solar-type stars with two-belt systems, 15 of which for the first time. Resolved disks are typically observed with radii >100 AU, larger than expected from a simple blackbody fit. Despite the absence of narrow spectral features for ice, we find that the shape of the continuum, combined with resolved outer/cold dust locations, can help constrain the grain size distribution and hint at the dust’s composition for each resolved system. Based on the combined Spitzer /IRS+Multiband Imaging Photometer (5-to-70 μ m) and Herschel /PACS (70-to-160 μ m) data set, and under the assumption of idealized spherical grains, we find that over half of resolved outer/cold belts are best fit with a mixed ice/rock composition. Minimum grain sizes are most often equal to the expected radiative blowout limit, regardless of composition. Three of four resolved systems around the solar-type stars, however, tend to have larger minimum grains compared to expectation from blowout ( f {sub MB} = a {sub min}/ a {sub BOS} ∼ 5). We also probe the disk architecture of 39 Herschel -unresolved systems by modeling their SEDs uniformly, and find them to be consistent with 31 single- and 8 two-belt debris systems.

  14. Theory and measurements of emittance preservation in plasma wakefield acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Frederico, Joel

    2016-12-01

    In this dissertation, we examine the preservation and measurement of emittance in the plasma wakefield acceleration blowout regime. Plasma wakefield acceleration (PWFA) is a revolutionary approach to accelerating charged particles that has been demonstrated to have the potential for gradients orders of magnitude greater than traditional approaches. The application of PWFA to the design of a linear collider will make new high energy physics research possible, but the design parameters must first be shown to be competitive with traditional methods. Emittance preservation is necessary in the design of a linear collider in order to maximize luminosity. We examine the conditions necessary for circular symmetry in the PWFA blowout regime, and demonstrate that current proposals meet these bounds. We also present an application of beam lamentation which describes the process of beam parameter and emittance matching. We show that the emittance growth saturates as a consequence of energy spread in the beam. The initial beam parameters determine the amount of emittance growth, while the contribution of energy spread is negligible. We also present a model for ion motion in the presence of a beam that is much more dense than the plasma. By combining the model of ion motion and emittance growth, we find the emittance growth due to ion motion is minimal in the case of marginal ion motion. In addition, we present a simulation that validates the ion motion model, which is under further development to examine emittance growth of both marginal and pronounced ion motion. Finally, we present a proof-of-concept of an emittance measurement which may enable the analysis of emittance preservation in future PWFA experiments.

  15. Systems for arctic spill response. Volume I. Final report, August 1977--March 1978

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, L.A.; Deslauriers, P.C.; DeBord, F.W.; Voelker, R.P.

    1978-03-01

    This final report summarizes the work accomplished under the program entitled 'Study to Define Arctic Pollution Response Systems and Develop Arctic Oil Pollution Response Project Plans.' The objective of the program was to determine the most cost effective, environmentally compatible, and technically feasible Coast Guard arctic pollution response system that can be used in projected oil spill scenarios to recover and dispose of spilled oil. The optimum arctic pollution response system was determined by establishing the cost and effectiveness of response for sixteen oil spill response situations, and developing six alternative Coast Guard arctic pollution response systems based on these situations. These six systems were developed with a recognition of three distinctly different types of operational requirements, those for thick stable ice, dynamic hummocky ice, and open water or light ice conditions. The optimum system was then identified as the result of a cost effectiveness analysis. The six arctic oil spill scenarios consisted of a gathering pipeline rupture in the nearshore Beaufort Sea, an oil well blowout from a very large reservoir in the nearshore Chukchi Sea, crude oil tanker casualties in Norton Sound and in the Navarin Basin region of the Bering Sea, an oil well blowout from an average sized reservoir in Bristol Bay, and a fuel oil spill resulting from the collision of a fuel oil barge in Unimak Pass. The optimum system provides for a 25% response level for the Norton Sound, Navarin Basin, Bristol Bay, and Unimak Pass scenarios, and a 50% response level for the Beaufort Sea and Chukchi Sea scenarios.

  16. Systems for arctic spill response. Volume II. Appendices. Final report, August 1977--March 1978

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, L.A.; Deslauriers, P.C.; DeBord, F.W.; Voelker, R.P.

    1978-03-01

    This final report summarizes the work accomplished under Phase I of the program entitled 'Study to Define Arctic Pollution Response Systems and Develop Arctic Oil Pollution Response Project Plans.' The objective of Phase I of the program was to determine the most cost effective, environmentally compatible, and technically feasible Coast Guard arctic pollution response system that can be used in projected oil spill scenarios to recover and dispose of spilled oil. The optimum arctic pollution response system was determined by establishing the cost and effectiveness of response for sixteen oil spill response situations, and developing six alternative Coast Guard arctic pollution response systems based on these situations. The optimum system was then identified as the result of a cost effectiveness analysis. The six arctic oil spill scenarios consisted of a gathering pipeline rupture in the nearshore Beaufort Sea, an oil well blowout from a very large reservoir in the nearshore Chukchi Sea, crude oil tanker casualties in Norton Sound and in the Navarin Basin region of the Bering Sea, an oil well blowout from an average sized reservoir in Bristol Bay, and a fuel oil spill resulting from the collision of a fuel oil barge in Unimak Pass. The optimum system provides for a 25% response level for the Norton Sound, Navarin Basin, Bristol Bay, and Unimak Pass scenarios, and a 50% response level for the Beaufort Sea and Chukchi Sea scenarios. Modifications in the optimum system required to extend its capability to subarctic applications in the Great Lakes, the northern rivers, and the northern coastal region were also identified.

  17. Concept design studies on the ITER HNB Duct Liner

    Energy Technology Data Exchange (ETDEWEB)

    Mistry, Sanjay, E-mail: sanjay.mistry@ccfe.ac.uk; Horvat, Andrej; Verhoeven, Roel; Xue, Yongkuan

    2013-10-15

    Highlights: •Engineering design of the ITER Heating Neutral Beam Duct Liner is outlined. •A vector-calculus method is used for calculations which evaluate directional heat flux on different scraper panel layouts. •A scraper panel layout with equal panel lengths and common thermal loading was achieved through these calculations. •The thermo-mechanical performance of a scraper panel satisfies ITER structural design criteria under a normal operation scenario. •Fast blow-out draining is used for complete emptying of a cooling arrangement. •Numerical simulations of the blow-out draining were carried out using RELAP5 and found to demonstrate satisfactory draining. -- Abstract: The Duct Liner for the International Thermonuclear Experimental Reactors (ITER) Heating Neutral Beam (HNB) system is a key component in the beam transport system. Power loading on the top and bottom beam scraping panels of the Duct Liner occurs primarily due to direct interception of the HNB and it is highest at the extreme steering angles of the beam. Furthermore, power loading due to direct interception is dependent on the size and orientation of the scraper panels with respect to the neutral beam axis. This paper outlines the design features of the proposed Duct Liner and describes the analysis performed to optimize the compatibility of the top and bottom scraper panels (also known as Duct Liner Modules) with a normal beam operation scenario. Thermo-mechanical analyses have been performed to validate the design of Duct Liner Modules incorporating deep-drilled cooling technology with a peak power density of 1.2 MW/m{sup 2} and incident power of 0.27 MW, and also to verify its conformity with ITER structural design criteria. Furthermore, numerical simulations of the transient draining procedure were performed by using a one-dimensional thermo-hydraulic code to demonstrate complete emptying of the proposed parallel-layout cooling circuit without any reliance on conventional gravity

  18. Mrk 71/NGC 2366: The Nearest Green Pea Analog

    Energy Technology Data Exchange (ETDEWEB)

    Micheva, Genoveva; Oey, M. S. [University of Michigan, 311 West Hall, 1085 S. University Avenue, Ann Arbor, MI 48109-1107 (United States); Jaskot, Anne E. [Department of Astronomy, Smith College, Northampton, MA 01063 (United States); James, Bethan L. [STScI, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

    2017-08-20

    We present the remarkable discovery that the dwarf irregular galaxy NGC 2366 is an excellent analog of the Green Pea (GP) galaxies, which are characterized by extremely high ionization parameters. The similarities are driven predominantly by the giant H ii region Markarian 71 (Mrk 71). We compare the system with GPs in terms of morphology, excitation properties, specific star-formation rate, kinematics, absorption of low-ionization species, reddening, and chemical abundance, and find consistencies throughout. Since extreme GPs are associated with both candidate and confirmed Lyman continuum (LyC) emitters, Mrk 71/NGC 2366 is thus also a good candidate for LyC escape. The spatially resolved data for this object show a superbubble blowout generated by mechanical feedback from one of its two super star clusters (SSCs), Knot B, while the extreme ionization properties are driven by the ≲1 Myr-old, enshrouded SSC Knot A, which has ∼10 times higher ionizing luminosity. Very massive stars (>100 M {sub ⊙}) may be present in this remarkable object. Ionization-parameter mapping indicates that the blowout region is optically thin in the LyC, and the general properties also suggest LyC escape in the line of sight. Mrk 71/NGC 2366 does differ from GPs in that it is one to two orders of magnitude less luminous. The presence of this faint GP analog and candidate LyC emitter (LCE) so close to us suggests that LCEs may be numerous and commonplace, and therefore could significantly contribute to the cosmic ionizing budget. Mrk 71/NGC 2366 offers an unprecedentedly detailed look at the viscera of a candidate LCE, and could clarify the mechanisms of LyC escape.

  19. FLUID DYNAMICS PROCESSES AT THE CENTRAL SAKHALIN FAULT (BASED ON OBSERVATIONS OF THE YUZHNO-SAKHALINSK MUD VOLCANO

    Directory of Open Access Journals (Sweden)

    Valery V. Ershov

    2012-01-01

    Full Text Available The Yuzhno-Sakhalinsk mud volcano is located in the southern part of the Sakhalin Island within the area of the Central Sakhalin fault, one of the largest disjunctive dislocations of the island. The volcano was monitored during field seasons in the period from 2005 to 2007, and data on flow rates, chemical and isotope compositions of gases, temperature and chemical composition of watermud mixture in the volcano’s blowouts were collected and analysed. During the observation period, seismic activity in the region under study was significantly variable in time and space. The monitoring results revealed «traces» of two earthquakes in the blowout activity of the Yuzhno-Sakhalinsk mud volcano – the Gornazavodsk earthquake, that took place on 17 (18 August 2006, and the Nevelsk earthquake of 2 August 2007. Based on results of our analyses of the field data and mathematical simulation data, it is possible to conclude that an additional inflow of «deep geofluids» could not have been a major trigger of the activity of the volcano after the earthquakes. In our opinion, all the observed anomalies may result from «water – rock – gas» interactions in the top part of the mud volcano’s feeder channel. A combination of water and gas flows in the volcano’s channel and silica-alumina rocks comprises a specific geochemical system that is sensitive to external (seismic impacts. Therefore, comprehensive consideration of physical and chemical processes within fluid-dynamic systems is required for assurance of correct interpretation of empirical data.

  20. Natural emissions of CO2 from the geosphere and their bearing on the geological storage of carbon dioxide

    International Nuclear Information System (INIS)

    Holloway, S.; Pearce, J.M.; Hards, V.L.; Ohsumi, T.; Gale, J.

    2007-01-01

    Carbon dioxide (CO 2 ) capture and storage has the potential to reduce CO 2 emissions from fossil fuel combustion. Although leakage from monitored CO 2 injection sites has been minimal to non-existent, experience from the natural gas storage industry suggests that, if it becomes a widely deployed technology, leaks may be expected from some storage sites. Natural occurrences of CO 2 in the geosphere, some of which have been exploited, provide insights into the types of emissions that might be expected from anthropogenic CO 2 storage sites. CO 2 emission sites are commonly found in clusters in CO 2 -prone geological provinces: the most common natural emissions sites in sedimentary basins consist of carbonated springs and mofettes. These represent at worst only a local hazard. In volcanic and hydrothermal provinces, more energetic emissions may occur due to active supply from degassing magma. These include rare, sudden emissions from fissures and craters that have caused fatalities. It is unlikely that such provinces would be considered for CO 2 storage. Major lake overturn events such as occurred at Lake Nyos in 1986 are considered highly unlikely to occur as a result of CO 2 storage, not least because CO 2 levels in lake waters can be monitored and remediated. Natural CO 2 fields indicate that under favourable conditions CO 2 can be retained in the subsurface for millions of years. The main risk from man-made CO 2 storage sites that does not have any close analogy in nature is considered to be a well blowout. A blowout that took place at a natural CO 2 field provides some indication of the likely hazard. (author)

  1. 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.

  2. 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.

  3. Investigation of Methane Oxy-Fuel Combustion in a Swirl-Stabilised Gas Turbine Model Combustor

    Directory of Open Access Journals (Sweden)

    Mao Li

    2017-05-01

    Full Text Available CO2 has a strong impact on both operability and emission behaviours in gas turbine combustors. In the present study, an atmospheric, preheated, swirl-stabilised optical gas turbine model combustor rig was employed. The primary objectives were to analyse the influence of CO2 on the fundamental characteristics of combustion, lean blowout (LBO limits, CO emission and flame structures. CO2 dilution effects were examined with three preheating temperatures (396.15, 431.15, and 466.15 K. The fundamental combustion characteristics were studied utilising chemical kinetic simulations. To study the influence of CO2 on the operational range of the combustor, equivalence ratio (Ф was varied from stoichiometric conditions to the LBO limits. CO emissions were measured at the exit of the combustor using a water-cooled probe over the entire operational range. The flame structures and locations were characterised by performing CH chemiluminescence imaging. The inverse Abel transformation was used to analyse the CH distribution on the axisymmetric plane of the combustor. Chemical kinetic modelling indicated that the CO2 resulted in a lower reaction rate compared with the CH4/air flame. Fundamental combustion properties such as laminar flame speed, ignition delay time and blowout residence time were found to be affected by CO2. The experimental results revealed that CO2 dilution resulted in a narrower operational range for the equivalence ratio. It was also found that CO2 had a strong inhibiting effect on CO burnout, which led to a higher concentration of CO in the combustion exhaust. CH chemiluminescence showed that the CO2 dilution did not have a significant impact on the flame structure.

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. Methane emissions from oceans, coasts, and freshwater habitats: New perspectives and feedbacks on climate

    Science.gov (United States)

    Hamdan, Leila J.; Wickland, Kimberly P.

    2016-01-01

    Methane is a powerful greenhouse gas, and atmospheric concentrations have risen 2.5 times since the beginning of the Industrial age. While much of this increase is attributed to anthropogenic sources, natural sources, which contribute between 35% and 50% of global methane emissions, are thought to have a role in the atmospheric methane increase, in part due to human influences. Methane emissions from many natural sources are sensitive to climate, and positive feedbacks from climate change and cultural eutrophication may promote increased emissions to the atmosphere. These natural sources include aquatic environments such as wetlands, freshwater lakes, streams and rivers, and estuarine, coastal, and marine systems. Furthermore, there are significant marine sediment stores of methane in the form of clathrates that are vulnerable to mobilization and release to the atmosphere from climate feedbacks, and subsurface thermogenic gas which in exceptional cases may be released following accidents and disasters (North Sea blowout and Deepwater Horizon Spill respectively). Understanding of natural sources, key processes, and controls on emission is continually evolving as new measurement and modeling capabilities develop, and different sources and processes are revealed. This special issue of Limnology and Oceanography gathers together diverse studies on methane production, consumption, and emissions from freshwater, estuarine, and marine systems, and provides a broad view of the current science on methane dynamics of aquatic ecosystems. Here, we provide a general overview of aquatic methane sources, their contribution to the global methane budget, and key uncertainties. We then briefly summarize the contributions to and highlights of this special issue.

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

    Directory of Open Access Journals (Sweden)

    Y. Tang

    2015-01-01

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

  12. Geopressure modeling from petrophysical data: An example from East Kalimantan

    Energy Technology Data Exchange (ETDEWEB)

    Herkommer, M.A. (Petrospec Computer Corp., Richardson, TX (United States))

    1994-07-01

    Localized models of abnormal formation pressure (geopressure) are important economic and safety tools frequently used for well planning and drilling operations. Simplified computer-based procedures have been developed that permit these models to be developed more rapidly and with greater accuracy. These techniques are broadly applicable to basins throughout the world where abnormal formation pressures occur. An example from the Attaka field of East Kalimantan, southeast Asia, shows how geopressure models are developed. Using petrophysical and engineering data, empirical correlations between observed pressure and petrophysical logs can be created by computer-assisted data-fitting techniques. These correlations serve as the basis for models of the geopressure. By performing repeated analyses on wells at various locations, contour maps on the top of abnormal geopressure can be created. Methods that are simple in their development and application make the task of geopressure estimation less formidable to the geologist and petroleum engineer. Further, more accurate estimates can significantly improve drilling speeds while reducing the incidence of stuck pipe, kicks, and blowouts. In general, geopressure estimates are used in all phases of drilling operations: To develop mud plans and specify equipment ratings, to assist in the recognition of geopressured formations and determination of mud weights, and to improve predictions at offset locations and geologically comparable areas.

  13. 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.

  14. Vulnerability Assessment of a Coastal Dune System at São Francisco do Sul Island, Santa Catarina, Brazil

    Science.gov (United States)

    Alquini, Fernanda; Bertoni, Duccio; Sarti, Giovanni; Ciccarelli, Daniela; Pozzebon, Alessandro; Ferreira de Melo Júnior, João Carlos; Voos Vieira, Celso

    2016-10-01

    In this paper a Coastal Dune Vulnerability Index (CDVI) has been applied on a beach located in the eastern side of Sao Francisco do Sul Island (Brazil). The aim of this study is to assess the vulnerability of a coastal dune system and to identify the areas that result most sensitive to environmental changes. The CDVI has been applied along six transects traced out on two sectors that have been selected based on dune characteristics: Zone A is characterized by well developed parabolic dunes, whereas Zone B is characterized by transverse dunes. The analysis involved 51 quantitative and qualitative variables, divided into five groups: geomorphological dune system condition, marine influence, Aeolian effect, vegetation condition and human effect. The total CDVI was computed as the unweighted average of the partial vulnerability indices. In summary, the total vulnerability can be classified as medium: the geomorphological factor must be monitored at Grande beach, in particular the blowouts in Zone A and the frontal dune retreat in Zone B. The results of the study confirm that the management of coastal areas might be improved using a tool such as the CDVI, which can be easily applied on a regular basis to take under control the factors that mostly affect the evolution of the site.

  15. 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.

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

    International Nuclear Information System (INIS)

    Silva, M.K.

    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. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Non-grey dimming events of KIC 8462852 from GTC spectrophotometry

    Science.gov (United States)

    Deeg, Hans J.; Alonso, Roi; Nespral, David; Boyajian, Tabetha S.

    2018-02-01

    We report ground-based spectrophotometry of KIC 8462852 obtained during its first dimming events since the end of the Kepler mission. The dimmings show a clear colour signature and are deeper in visual blue than in red wavelengths. The wavelength dependency of the flux loss can be described with an absorption Ångström coefficient of 2.19 ± 0.45, which is compatible with absorption by optically thin dust with particle sizes of the order of 0.0015 to 0.15 μm. These particles would be smaller than is required to be resistant against blow-out by radiation pressure when close to the star. During occultation events, these particles must be replenished from a comoving body on time-scales of days. If dust is indeed the source of the dimming events of KIC 8462852, deeper dimming events should show more neutral colours, as is expected from optically thick absorbers. The individual reduced spectra of the target and reference stars are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/610/L12

  19. 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.

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

    International Nuclear Information System (INIS)

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

    1985-01-01

    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

  1. 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.

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

    International Nuclear Information System (INIS)

    Gilbert, H.; Fretthold, J.K.; Rainer, F.; Bergman, W.; Beason, D.

    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

  3. Hydrodynamic effects of nuclear active galaxy winds on host galaxies

    International Nuclear Information System (INIS)

    Schiano, A.V.R.

    1984-01-01

    In order to test the hypothesized existence of a powerful, thermal wind in active galactic nuclei, the hydrodynamic effects of such a wind on a model galactic interstellar medium (ISM) are investigated. The properties of several model ISMs are derived from observations of the Milky Way's ISM and those of nearby spiral and elliptical galaxies. The propagation of the wind into the low density gas component of the ISM is studied using the Kompaneets approximation of a strong explosion in an exponential atmosphere. Flattened gas distributions are shown to experience blow-out of wind gas along the symmetry axis. Next, the interaction of dense, interstellar clouds with the wind is investigated. The stability and mass loss of clouds in the wind are studied and it is proposed that clouds survive the encounter with the wind over large timescales. It is proposed that the narrow emission line regions (NELR) of active galaxies are the result of the interaction of active nuclei photons and a thermal wind on large, interstellar clouds

  4. Laminar partially premixed flame stability - application to domestic burner; Stabilite de flammes laminaires partiellement premelangees. Application aux bruleurs domestiques

    Energy Technology Data Exchange (ETDEWEB)

    Lacour, C.

    2006-05-15

    Phenomena responsible of partially premixed laminar flame stabilisation are investigated on a rich premixed burner configuration. The structure and aerodynamic of the flame generated by a cooking model burner are characterized by Planar Laser Induced Fluorescence of OH radical and Particle Image Velocimetry. The flame behaviour is studied from a stable reference case toward blow-out by varying the flow inlet conditions, the burner geometry and its thermal properties. The flame can be considered as two neighbour and independent reactive zones, each consisting of a double edge flame. The upper double flame stabilisation is similar to the one of a Bunsen burner with a flame-holder attached base and a flame tip stabilized in the flow according to the ratio of the flow velocity and flame speed of the rich pre-mixture. The bottom double flame is stabilized at the crossing point of the stoichiometric flame speed. The flame is finally blown out when there is no more crossing point. (author)

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    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. (technical note)

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

    International Nuclear Information System (INIS)

    Reed, Mark; Ekrol, Narve; Rye, Henrik; Turner, Liam

    1999-01-01

    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 m 3 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)

  7. Building 834 -- Cost-effective and innovative design of remediation systems using surplus equipment from former weapons programs

    Energy Technology Data Exchange (ETDEWEB)

    Daley, P.F.; Landgraf, R.K.; Lima, M.R.; Lamarre, A.L.

    1995-07-01

    The Building 834 Complex at the Lawrence Livermore National Laboratory (LLNL) Site 300, has been used by the weapons development programs at LLNL as a testing facility for measuring component response to environmental stresses such as extreme temperature. The heat-exchange system at the facility used trichloroethene TCE, at times with adjuvants, as the primary heat-transfer media for over 20 years. Accidental spills, pipe failures, and seal blowouts over that period contributed to a substantial contaminant plume in a perched water-bearing zone underlying the Complex. Individual wells near the source area have produced ground water samples with TCE concentrations exceeding 800,000 ppb. In the last several years, the authors have developed a modular ground water and soil vapor extraction system for remediating the plume source area. The modular facility design permits the testing of new technologies to expedite remediation, and/or reduce the quantity of hazardous wastes generated as byproducts of the primary remedial activities. To contain costs, the authors have used equipment and components recycled from the original Building 834 Complex heat-exchange system, and surplus equipment from other LLNL divisions. The authors have executed two large-scale tests of energy injection systems for TCE destruction in air (a free-air electron beam and a pulsed, ultraviolet photolysis system), and a soil heating test for accelerating vapor extraction. New work plans for this unique site are being prepared, incorporating the lessons learned in developing new technology with recycled equipment.

  8. 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.

  9. 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.

  10. 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

  11. Coherent transition radiation from a laser wakefield accelerator as an electron bunch diagnostic

    International Nuclear Information System (INIS)

    Tilborg, J. van; Geddes, C.G.R.; Toth, C.; Esarey, E.; Schroeder, C.B.; Martin, M.C.; Hao, Z.; Leemans, W.P.

    2004-01-01

    The observation and modeling of coherent transition radiation from femtosecond laser accelerated electron bunches is discussed. The coherent transition radiation, scaling quadratically with bunch charge, is generated as the electrons transit the plasma-vacuum boundary. Due to the limited transverse radius of the plasma boundary, diffraction effects will strongly modify the angular distribution and the total energy radiated is reduced compared to an infinite transverse boundary. The multi-nC electron bunches, concentrated in a length of a few plasma periods (several tens of microns), experience partial charge neutralization while propagating inside the plasma towards the boundary. This reduces the space-charge blowout of the beam, allowing for coherent radiation at relatively high frequencies (several THz). The charge distribution of the electron bunch at the plasma-vacuum boundary can be derived from Fourier analysis of the coherent part of the transition radiation spectrum. A Michelson interferometer was used to measure the coherent spectrum, and electron bunches with duration on the order of 50 fs (rms) were observed

  12. Captains of industry

    International Nuclear Information System (INIS)

    Black, L.

    2000-01-01

    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

  13. 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.

  14. The Canadian experience in frontier environmental protection

    International Nuclear Information System (INIS)

    Jones, G.H.

    1991-01-01

    Early Canadian frontier exploration (from 1955 onshore and from 1966 for offshore drilling) caused insignificant public concern. The 1967-1968 Torrey Canyon Tanker and Santa Barbara disasters roused public opinion and governments. In Canada, 1969-1970 Arctic gas blowouts, a tanker disaster, and damage to the 'Manhattan' exacerbated concerns and resulted in new environmental regulatory constraints. From 1970, the Arctic Petroleum Operations Association learned to operate safely with environmental responsibility. It studied physical environment for design criteria, and the biological and human environment to ameliorate impact. APOA's research projects covered sea-ice, permafrost, sea-bottom, oil-spills, bird and mammal migration, fish habitat, food chains, oceanography, meteorology, hunters'/trappers' harvests, etc. In 1971 Eastcoast Petroleum Operators' Association and Alaska Oil and Gas Association followed APOA's cooperative research model. EPOA stressed icebergs and fisheries. Certain research was handled by the Canadian Offshore Oil Spill Research Association. By the mid-1980s these associations had undertaken $70,000,000 of environmental oriented research, with equivalent additional work by member companies on specific needs and similar sums by Federal agencies often working with industry on complementary research. The frontier associations then merged with the Canadian Petroleum Association, already active environmentally in western Canada. Working with government and informing environmental interest groups, the public, natives, and local groups, most Canadian frontier petroleum operations proceeded with minimal delay and environmental disturbance

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

    International Nuclear Information System (INIS)

    Bowden-Smith, J.

    2001-01-01

    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

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

    International Nuclear Information System (INIS)

    Hodson, P.

    2010-01-01

    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.

  17. Risk Management at NASA and Its Applicability to the Oil and Gas Industry

    Science.gov (United States)

    Kaplan, David

    2018-01-01

    NASA has a world-class capability for quantitatively assessing the risk of highly-complex, isolated engineering structures operated in extremely hostile environments. In particular, the International Space Station (ISS) represents a reasonable risk analog for High Pressure, High Temperature drilling and production operations on deepwater rigs. Through a long-term U.S. Government Interagency Agreement, BSEE has partnered with NASA to modify NASA's Probabilistic Risk Assessment (PRA) capabilities for application to deepwater drilling and production operations. The immediate focus of the activity will be to modify NASA PRA Procedure Guides and Methodology Documents to make them applicable to the Oil &Gas Industry. The next step will be for NASA to produce a PRA for a critical drilling system component, such as a Blowout Preventer (BOP). Subsequent activities will be for NASA and industry partners to jointly develop increasingly complex PRA's that analyze other critical drilling and production system components, including both hardware and human reliability. In the presentation, NASA will provide the objectives, schedule, and current status of its PRA activities for BSEE. Additionally, NASA has a Space Act Agreement with Anadarko Petroleum Corporation to develop a PRA for a generic 20K BOP. NASA will summarize some of the preliminary insights gained to date from that 20K BOP PRA as an example of the distinction between quantitative versus qualitative risk assessment.

  18. Reconstruction of Orbital Floor With Auricular Concha.

    Science.gov (United States)

    Seven, Ergin; Tellioglu, Ali Teoman; Inozu, Emre; Ozakpinar, Hulda Rifat; Horoz, Ugur; Eryilmaz, Avni Tolga; Karamursel, Sebat

    2017-10-01

    Orbital floor fractures of varying sizes commonly occur after orbital injuries and remain a serious challenge. Serious complications of such fractures include enopthalmos, restriction of extraocular movement, and diplopia. There is a dearth of literature that can be applied widely, easily, and successfully in all such situations, and therefore there is no consensus on the treatment protocol of this pathology yet. Autogenous grafts and alloplastic and allogenic materials with a wide variety of advantages and disadvantages have been discussed. The value of preoperative and postoperative ophthalmological examination should be standard of care in all orbital fracture patients. An ideal reconstructed orbital floor fracture should accelerate the restoration of orbital function with acceptable cosmetic results. Management parameters of orbital fractures such as timing of surgery, incision type, and implant materials, though widely discussed, remain controversial. In this study, 55 patients with orbital floor fractures surgically reconstructed with conchal cartilage grafts between 2008 and 2014 were retrospectively evaluated. Complications and long-time follow-up visit results have been reported with clinical and radiographic findings. The aim of this study was to present the authors' clinical experiences of reconstruction of blow-out fractures with auricular conchal graft and to evaluate the other materials available for use.

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

    International Nuclear Information System (INIS)

    Yamazaki, Hideya; Kodani, Naohiro; Ogita, Mikio; Sato, Kengo; Himei, Kengo

    2011-01-01

    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

  20. Safety concerns in ultrahigh pressure capillary liquid chromatography using air-driven pumps.

    Science.gov (United States)

    Xiang, Yanqiao; Maynes, Daniel R; Lee, Milton L

    2003-04-04

    Ultrahigh pressure liquid chromatography (UHPLC) is an emerging technique which utilizes pressures higher than 10,000 p.s.i. to overcome the flow resistance imposed when using very small particles as packing materials in fused-silica capillary columns (1 p.s.i.=6894.76 Pa). This technique has demonstrated exceptionally high separation speeds and chromatographic efficiencies. However, safety is a concern when extremely high pressures are used. In this study, the safety aspects of capillary column rupture during operation were identified and carefully evaluated. First, liquid jets may be formed as a result of blow-out of the on-column frits or from rupture of the capillary at or near the column inlet. Second, incorrect installation of the capillary at the injector, failure of the ferrule used in the capillary connection, or rupture of the capillary can produce high speed projectiles of silica particles or column fragments. Experiments were carried out in the laboratory to produce liquid (water) jets and capillary projectiles using a UHPLC system, and the power density, an important parameter describing water jets in industrial practice, was calculated. Experimental results were in accordance with theoretical calculations. Both indicated that water jets and capillary projectiles under ultrahigh pressures might lead to skin penetration under limited conditions. The use of a plexiglass shroud to cover an initial length of the installed capillary column can eliminate any safety-related concerns about liquid jets or capillary projectiles.

  1. Distribution of hydrocarbons released during the 2010 MC252 oil spill in deep offshore waters

    International Nuclear Information System (INIS)

    Spier, Chelsea; Stringfellow, William T.; Hazen, Terry C.; Conrad, Mark

    2013-01-01

    The explosion of the Deepwater Horizon oil platform on April 20th, 2010 resulted in the second largest oil spill in history. The distribution and chemical composition of hydrocarbons within a 45 km radius of the blowout was investigated. All available certified hydrocarbon data were acquired from NOAA and BP. The distribution of hydrocarbons was found to be dispersed over a wider area in subsurface waters than previously predicted or reported. A deepwater hydrocarbon plume predicted by models was verified and additional plumes were identified. Because the samples were not collected systematically, there is still some question about the presence and persistence of an 865 m depth plume predicted by models. Water soluble compounds were extracted from the rising oil in deepwater, and were found at potentially toxic levels outside of areas previously reported to contain hydrocarbons. Application of subsurface dispersants was found to increase hydrocarbon concentration in subsurface waters. - Highlights: ► The hydrocarbon distribution was more widely spread than previously predicted or reported. ► 4 subsurface plumes were identified. ► More soluble compounds were preferentially extracted in the deepwater. ► Percentage of detectable results is a useful data analysis technique. ► Subsurface dispersants application increased hydrocarbons in subsurface waters. - All available certified Deepwater Horizon data was used to determine the spatial, temporal, and chemical distribution of hydrocarbons in subsurface of the Gulf of Mexico.

  2. 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.

  3. Posttraumatic Orbital Emphysema: A Numerical Model

    Directory of Open Access Journals (Sweden)

    Andrzej Skorek

    2014-01-01

    Full Text Available Orbital emphysema is a common symptom accompanying orbital fracture. The pathomechanism is still not recognized and the usually assumed cause, elevated pressure in the upper airways connected with sneezing or coughing, does not always contribute to the occurrence of this type of fracture. Observations based on the finite model (simulating blowout type fracture of the deformations of the inferior orbital wall after a strike in its lower rim. Authors created a computer numeric model of the orbit with specified features—thickness and resilience modulus. During simulation an evenly spread 14400 N force was applied to the nodular points in the inferior rim (the maximal value not causing cracking of the outer rim, but only ruptures in the inferior wall. The observation was made from 1·10-3 to 1·10-2 second after a strike. Right after a strike dislocations of the inferior orbital wall toward the maxillary sinus were observed. Afterwards a retrograde wave of the dislocation of the inferior wall toward the orbit was noticed. Overall dislocation amplitude reached about 6 mm. Based on a numeric model of the orbit submitted to a strike in the inferior wall an existence of a retrograde shock wave causing orbital emphysema has been found.

  4. 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.

  5. 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.

  6. Oil spill studies: A review of ecological effects

    Science.gov (United States)

    Teal, John M.; Howarth, Robert W.

    1984-01-01

    We reviewed seven particularly well known and/or studied oil spills that have occurred since the National Academy of Sciences 1975 report, “Petroleum in the Marine Environment” or that occurred prior to that report but about which significant new information has since been acquired. The spills studied were from the barge Florida, and tankers Arrow, Argo Merchant, Amoco Cadiz, and Tsesis and blowouts from the Bravo and Ixtoc I platforms. These “best” studies yield only limited insight into effects because they lack controls and have a high degree of natural variability. The Tsesis, Florida, and Amoco Cadiz cases are exceptional since they occurred in areas of ongoing research programs and had nearby areas suitable for controls. Oil spills have produced measurable effects on ecosystems that have not been readily predictable from laboratory studies on isolated organisms. However, ecosystemlevel interactions are poorly understood even without the complications resulting from effects of pollution. These generalizations emerge: oil regularly reaches sediments after a spill; oil in anoxic sediments is persistent; oil regularly contaminates Zooplankton and benthic invertebrates; fish are also contaminated, but to a lesser extent; oil contamination decreases the abundance and diversity of benthic communities.

  7. Generation and measurement of velocity bunched ultrashort bunch of pC charge

    Directory of Open Access Journals (Sweden)

    X. H. Lu

    2015-03-01

    Full Text Available In this paper, we discuss the velocity compression in a short rf linac of an electron bunch from a rf photoinjector operated in the blowout regime. Particle tracking simulations shows that with a beam charge of 2 pC an ultrashort bunch duration of 16 fs can be obtained at a tight longitudinal focus downstream of the linac. A simplified coherent transition radiation (CTR spectrum method is developed to enable the measurement of ultrashort (sub-50 fs bunches at low bunch energy (5 MeV and low bunch charges (<10  pC. In this method, the ratio of the radiation energy selected by two narrow bandwidth filters is used to estimate the bunch length. The contribution to the coherent form factor of the large transverse size of the bunch suppresses the radiation signal significantly and is included in the analysis. The experiment was performed at the UCLA Pegasus photoinjector laboratory. The measurement results show bunches of sub-40 fs with 2 pC of charge well consistent with the simulation using actual experimental conditions. These results open the way to the generation of ultrashort bunches with time-duration below 10 fs once some of the limitations of the setup (rf phase jitter, amplitude instability and low field in the gun limited by breakdown are corrected.

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

    Science.gov (United States)

    Hwang, Kun; Kim, Joo Ho

    2014-11-01

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

  9. Meteorite search in the deflation basins in Lea County, New Mexico and Winkler County, Texas, USA: Discovery of Lea County 003 (H4)

    Energy Technology Data Exchange (ETDEWEB)

    Mikouchi, T; Buchanan, P C; Zolensky, M E; Welten, K C; Hutchison, R; Hutchison, M

    2000-01-14

    During the past few decades great numbers of meteorites have been recovered from the ice accumulation zones of Antarctica and from the vast Sahara. Although these two great deserts are the two most productive areas, the Southern High Plains in USA (New Mexico and Texas) and Nullarbor Plain, Western Australia have great potential for meteorite recovery. The number of meteorite finds from Roosevelt County, New Mexico alone exceeds 100 in only approximately 11 km{sup 2} area. Most meteorites from this area have been found on the floors of active deflation basins (blowouts) that have been excavated from a mantle of sand dunes. This area has no apparent fluvial or permafrost activity within the last 50,000 years, suggesting that only prevailing winds and natural aridity aid in the concentration and preservation of meteorites. The authors investigated these deflation surfaces in Lea County (the SE corner of New Mexico) and neighboring Winkler County, Texas following a prior search in this area which found two chondrites. They found a tiny H4 chondrite in this search and here they report its mineralogy and petrology along with preliminary data on its exposure history.

  10. 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. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  11. Shear Ram Verification Test Protocol (VTP) Best Practices

    Energy Technology Data Exchange (ETDEWEB)

    Lindley, Roy A. [Argonne National Lab. (ANL), Argonne, IL (United States); Braun, Joseph C. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-01-01

    A blowout preventer (BOP) is a critical component used on subsea oil and gas wells during drilling, completion, and workover operations on the U. S. outer continental shelf (OCS). The purpose of the BOP is to seal oil and gas wells, and in the case of an emergency well-control event, to prevent the uncontrolled release of hydrocarbons. One of the most important components of the BOP is the hydraulically operated blind shear ram (BSR) that shears drilling-related components, such as drill pipes, casings, tubings, and wire-related tools that may have been placed in the well. In addition to shearing these components, the BSR must form a seal to keep hydrocarbons within the well bore, even when under the highest well-fluid pressures expected. The purpose of this document is for Argonne National Laboratory (ANL) to provide an independent view, based on current regulations, and best practices for testing and confirming the operability and suitability of BSRs under realistic (or actual) well conditions.

  12. Flashback Characteristics of Syngas-Type Fuels Under Steady and Pulsating Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Tim Lieuwen

    2007-09-30

    The objective of this project was to improve understanding and modeling of flashback, a significant issue in low emissions combustors containing high levels of hydrogen. Experimental studies were performed over a range of fuel compositions, flow velocities, reactant temperatures, and combustor pressures to study the factors leading to flashback. In addition, high speed imaging of the flashback phenomenon was obtained. One of the key conclusions of this study was that there existed multiple mechanisms which lead to flashback, each with different underlying parametric dependencies. Specifically, two mechanisms of 'flashback' were noted: rapid flashback into the premixer, presumably through the boundary layer, and movement of the static flame position upstream along the centerbody. The former and latter mechanisms were observed at high and low hydrogen concentrations. In the latter mechanism, flame temperature ratio, not flame speed, appeared to be the key parameter describing flashback tendencies. We suggested that this was due to an alteration of the vortex breakdown location by the adverse pressure gradient upstream of the flame, similar to the mechanism proposed by Sattelmayer and co-workers [1]. As such, a key conclusion here was that classical flashback scalings derived from, e.g., Bunsen flames, were not relevant for some parameter regimes found in swirling flames. In addition, it was found that in certain situations, pure H2 flames could not be stabilized, i.e., the flame would either flashback or blowout at ignition. This result could have significant implications on the development of future high hydrogen turbine systems.

  13. 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.

  14. 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)

  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. A cusp-shaped jet observed by IRIS and SDO

    Science.gov (United States)

    Zhang, Yuzong; Zhang, Jun

    2017-04-01

    On 2014 August 29, the trigger and evolution of a cusp-shaped jet were captured in detail at 1330 Å by the Interface Region Imaging Spectrograph. At first, two neighboring mini-prominences arose in turn from the low solar atmosphere and collided with a loop-like system over them. The collisions between the loop-like system and the mini-prominences lead to the blowout, and then a cusp-shaped jet formed with a spire and an arch-base. In the spire, many brightening blobs originating from the junction between the spire and the arch-base moved upward in a rotating manner and then in a straight line in the late phase of the jet. In the arch-base, dark and bright material simultaneously tracked in a fan-like structure, and the majority of the material moved along the fan's threads. At the later phase of the jet's evolution, bidirectional flows emptied the arch-base, while downflows emptied the spire, thus making the jet entirely vanish. The extremely detailed observations in this study shed new light on how magnetic reconnection alters the inner topological structure of a jet and provides a beneficial complement for understanding current jet models.

  17. A Fast Propagating Extreme-Ultraviolet Wave Associated with a Mini-filament Eruption

    Science.gov (United States)

    Zheng, Ruisheng; Jiang, Yunchun; Yang, Jiayan; Bi, Yi; Hong, Junchao; Yang, Dan; Yang, Bo

    2012-07-01

    The fast extreme-ultraviolet (EUV) waves (>1000 km s-1) in the solar corona were very rare in the past. Taking advantage of the high temporal and spatial resolution of the Solar Dynamics Observatory observations, we present a fast EUV wave associated with a mini-filament eruption, a C1.0 flare, and a coronal mass ejection (CME) on 2011 September 30. The event took place at the periphery between two active regions (ARs). The mini-filament rapidly erupted as a blowout jet associated with a flare and a CME. The CME front was likely developed from the large-scale overlying loops. The wave onset was nearly simultaneous with the start of the jet and the flare. The wave departed far from the flare center and showed a close location relative to the rapid jet. The wave had an initial speed of about 1100 km s-1 and a slight deceleration in the last phase, and the velocity decreased to about 500 km s-1. The wave propagated in a narrow angle extent, likely to avoid the ARs on both sides. All the results provide evidence that the fast EUV wave was a fast-mode MHD wave. The wave resisted being driven by the CME, because it opened up the large-scale loops and its front likely formed later than the wave. The wave was most likely triggered by the jet, due to their close timing and location relations.

  18. Environmental factors along the Northern Sea Route

    International Nuclear Information System (INIS)

    Fjeld, P.E.

    1993-01-01

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Li, Haidong; Jiang, Yunchun; Yang, Jiayan; Yang, Bo; Xu, Zhe; Hong, Junchao; Bi, Yi, E-mail: lhd@ynao.ac.cn [Yunnan Observatories, Chinese Academy of Sciences, 396 Yangfangwang, Guandu District, Kunming, 650216 (China)

    2017-02-20

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

  20. Surface stability test plan for protective barriers

    International Nuclear Information System (INIS)

    Ligotke, M.W.

    1989-01-01

    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

  1. Self-Guiding of Ultrashort Relativistically Intense Laser Pulses to the Limit of Nonlinear Pump Depletion

    International Nuclear Information System (INIS)

    Ralph, J. E.; Marsh, K. A.; Pak, A. E.; Lu, W.; Clayton, C. E.; Fang, F.; Joshi, C.; Tsung, F. S.; Mori, W. B.

    2009-01-01

    A study of self-guiding of ultra short, relativistically intense laser pulses is presented. Here, the laser pulse length is on the order of the nonlinear plasma wavelength and the normalized vector potential is greater than one. Self-guiding of ultrashort laser pulses over tens of Rayliegh lengths is possible when driving a highly nonlinear wake. In this case, self-guiding is limited by nonlinear pump depletion. Erosion of the pulse due to diffraction at the head of the laser pulse is minimized for spot sizes close to the blow-out radius. This is due to the slowing of the group velocity of the photons at the head of the laser pulse. Using an approximately 10 TW Ti:Sapphire laser with a pulse length of approximately 50 fs, experimental results are presented showing self-guiding over lengths exceeding 30 Rayliegh lengths in various length Helium gas jets. Fully explicit 3D PIC simulations supporting the experimental results are also presented.

  2. Endoscopic anatomy of the orbital floor and maxillary sinus.

    Science.gov (United States)

    Moore, Corey C; Bromwich, Matthew; Roth, Kathy; Matic, Damir B

    2008-01-01

    Endoscopic repair of orbital blow-out fractures could become a predictable and efficient treatment alternative to traditional methods. However, maxillary sinus endoscopy provides a complex and disorienting view of the orbital floor. To be a useful and consistent technique for providing access to the orbital floor, specific knowledge of maxillary endoscopic anatomy is required. The purpose of the study was to provide an anatomic description of the orbital floor via the endoscopic approach. Objectives include defining consistent landmarks for use in endoscopic repair of orbital floor fractures. Using 0- and 30-degree rigid endoscopes, 6 fresh cadavers (12 maxillary sinuses) were examined via a standard Caldwell-Luc approach. Computed tomographic scans, plastic molds, and digital images were used to compare observable averages within bony anatomy. Potential bony landmarks were correlated with soft-tissue anatomy in fresh specimens. The maxillary ostium, orbital floor, and lateral ethmoid air cells were visualized, and their structures were described. Observations were made in relation to the anatomy of the orbital floor and maxillary sinus, including fracture pattern and force transmission pathways. An "orbitomaxillary" sinus bony thickening was identified and described for the first time. This study provides the basis for further refinement of surgical technique and opens the door for future clinical trials using endoscopic repair.

  3. 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.

  4. The maxillae: integrated and applied anatomy relevant to dentistry.

    Science.gov (United States)

    Du Tolt, D F; Nortjé, Curly

    2003-09-01

    The union of the two paired maxillae form the whole upper jaw. Individual components of the maxilla contribute to the formation of the face, nose, mouth and orbit. The bony surfaces are in relation to the infratemporal and pterygopalatine fossae. Grooves, openings and foramina lend passage to structures such as the infra-orbital, posterior superior alveolar, nasopalatine and greater palatine nerves. These nerves are of great importance for regional anaesthesia in dentistry. The maxillary antrum of Highmore is frequently affected by pathological processes such as accidental tooth root impaction during an extraction procedure, sinusitis, cysts, fractures (LeFort) and tumours. Fast-growing maxillary sinus tumours often breach the thin walls of this cavity and encroach upon adjacent structures such as the orbit, nose, cheek, infratemporal fossa and mouth. 'Blow-out' fractures through the orbital component may result in nerve and muscle entrapment. Alveolar processes form an arcade for the two incisors, one canine, two premolars and three molars on each side. Knowledge of regional and applied anatomy, relevant to the maxillae, is essential when considering diagnostic imaging by X-rays, CT, and MRI.

  5. Measurement of self-shaped ellipsoidal bunches from a photoinjector with postacceleration

    Directory of Open Access Journals (Sweden)

    Brendan O’Shea

    2011-01-01

    Full Text Available Recent work has shown the possibility of generating self-shaped ellipsoidal beams with properties commensurate with the requirements of future light sources such as free-electron lasers and inverse Compton sources. In this so-termed “blowout” regime, short laser bunches are transformed via photoemission into short electron bunches which then self-consistently evolve into nearly uniform-density ellipsoids under space-charge forces. We report here on the first blowout studies conducted in collaboration between the UCLA Particle Beam Physics Lab and the Photo Injector Test Facility, Zeuthen (PITZ. The measurements conducted at the PITZ photoinjector facility examine the evolution of 750 pC, 2.7 ps FWHM electron bunches born in an L-band photoinjector and subsequently accelerated through a nine-cell L-band booster for a resulting energy of 12 MeV. These measurements represent the first observations of self-shaped ellipsoid evolution under postinjector acceleration, a key step in demonstrating the utility of such self-shaped beams at higher energy, where the advantages in both transverse and longitudinal and transverse phase space may be exploited in creating very high brightness beams.

  6. 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.

  7. Simulation ofDeepwater Horizonoil plume reveals substrate specialization within a complex community of hydrocarbon degraders.

    Science.gov (United States)

    Hu, Ping; Dubinsky, Eric A; Probst, Alexander J; Wang, Jian; Sieber, Christian M K; Tom, Lauren M; Gardinali, Piero R; Banfield, Jillian F; Atlas, Ronald M; Andersen, Gary L

    2017-07-11

    The Deepwater Horizon (DWH) accident released an estimated 4.1 million barrels of oil and 10 10 mol of natural gas into the Gulf of Mexico, forming deep-sea plumes of dispersed oil droplets and dissolved gases that were largely degraded by bacteria. During the course of this 3-mo disaster a series of different bacterial taxa were enriched in succession within deep plumes, but the metabolic capabilities of the different populations that controlled degradation rates of crude oil components are poorly understood. We experimentally reproduced dispersed plumes of fine oil droplets in Gulf of Mexico seawater and successfully replicated the enrichment and succession of the principal oil-degrading bacteria observed during the DWH event. We recovered near-complete genomes, whose phylogeny matched those of the principal biodegrading taxa observed in the field, including the DWH Oceanospirillales (now identified as a Bermanella species), multiple species of Colwellia , Cycloclasticus , and other members of Gammaproteobacteria, Flavobacteria, and Rhodobacteria. Metabolic pathway analysis, combined with hydrocarbon compositional analysis and species abundance data, revealed substrate specialization that explained the successional pattern of oil-degrading bacteria. The fastest-growing bacteria used short-chain alkanes. The analyses also uncovered potential cooperative and competitive relationships, even among close relatives. We conclude that patterns of microbial succession following deep ocean hydrocarbon blowouts are predictable and primarily driven by the availability of liquid petroleum hydrocarbons rather than natural gases.

  8. Clinico-radiologic findings of entrapped inferior oblique muscle in a fracture of the orbital floor.

    Science.gov (United States)

    Kim, Soo; Kim, Taik-Kun; Kim, Seung-Hyun

    2009-09-01

    A 51-year old man presented with vertical and torsional diplopia after reduction of a blowout fracture at another hospital one year ago. He had no anormalies of head position and 14 prism diopters (PD) right hypertropia (RHT) in the primary position. In upgaze no vertical deviation was found, and hyperdeviation on downgaze was 35PD. Bielschowsky head tilt test showed a negative response. Distinct superior oblique (SO) and inferior rectus (IR) underaction of the right eye was noted but IO overaction was mild on the ocular version test. Double Maddox rod test (DMRT) revealed 10-degree extorsion, but fundus extorsion was minimal in the right eye.Thin-section coronal CT scan showed that there was no fracture line on the anterior orbital floor, but a fracture remained on the posterior orbital floor. Also, the anterior part of the right inferior oblique muscle was vertically reoriented and the medial portion of the inferior oblique muscle was not traced on the coronal CT scan. The patient underwent 14 mm right IO recession and 3 mm right IR resection. One month after the surgery, his vertical and torsional diplopia were eliminated in the primary position.

  9. 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

    2002-07-01

    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

  10. New techniques for high pressure falling sphere viscosimetry in DIA-type large volume presses

    Science.gov (United States)

    Mueller, Hans J.; Beckmann, Felix; Dobson, David P.; Hunt, Simon A.; Lathe, Christian; Stroncik, Nicole

    2014-07-01

    Here we report recent technical advances that enable viscosity measurements in two DIA-type multi-anvil apparatus with a maximum of 250 tons and 1750 tons. We anticipate that this system will enable viscosity measurements for the pressures up to about 30 GPa. 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. This 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 demonstrate using of X-ray transparent cubic boron nitride-anvils (single-stage DIA) and slotted carbide anvils (double-stage DIA) to make the whole melting chamber accessible for the high pressure X-radiography system. Results are demonstrated with viscosity measurements following Stokes' Law by evaluation of X-radiography sequences taken by a camera equipped with a charge-coupled device sensor (CCD-camera) at pressures of 5 GPa as well as 10 GPa and temperatures of 1890 K.

  11. Study of methane solubility in oil base used in oil base drilling fluid; Estudo da solubilidade de metano em base oleo utilizada em fluido de perfuracao base oleo

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Carolina Teixeira da; Mariolani, Jose Ricardo Lenzi [Universidade Estadual de Campinas, SP (Brazil); Ribeiro, Paulo Roberto; Lomba, Rosana Fatima Teixeira; Bonet, Euclides Jose

    2004-07-01

    During drilling a well, it is necessary to prevent and control high pressurized zones because while drilling on those zones, could occur a kick if the formation pressure were higher then downhole pressure, allowing the entering of undesirables fluids from the formation to the wellbore. If the well is not controlled this kick could became a blowout, generating damages to the environment, to the equipment and the human life. When drilling using oil-based mud, the concern related to the well control would be higher due the gas solubility in the mud, which could make it hard to detect the kick, especially in deep and ultra deep waters. In this work we have studied the interaction between methane and organic liquids used in drilling fluids, and the measurement and analysis of the thermodynamic properties of those gas liquid mixtures. There have been measured parameters like the oil formation volume factor (FVF{sub o}), bubble pressure, solubility (Rs) and the density of the saturated liquid in function of methane mole fraction and temperature. The results have shown that the gas solubility, at downhole conditions and during kick circulation, is a factor very important to the safety during well drilling in deep and ultra deep waters. (author)

  12. 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.

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

    KAUST Repository

    Gonçalves, Rafael C.

    2016-03-02

    An uncertainty quantification framework is developed for the DeepC Oil Model based on a nonintrusive polynomial chaos method. This allows the model\\'s output to be presented in a probabilistic framework so that the model\\'s predictions reflect the uncertainty in the model\\'s input data. The new capability is illustrated by simulating the far-field dispersal of oil in a Deepwater Horizon blowout scenario. The uncertain input consisted of ocean current and oil droplet size data and the main model output analyzed is the ensuing oil concentration in the Gulf of Mexico. A 1331 member ensemble was used to construct a surrogate for the model which was then mined for statistical information. The mean and standard deviations in the oil concentration were calculated for up to 30 days, and the total contribution of each input parameter to the model\\'s uncertainty was quantified at different depths. Also, probability density functions of oil concentration were constructed by sampling the surrogate and used to elaborate probabilistic hazard maps of oil impact. The performance of the surrogate was constantly monitored in order to demarcate the space-time zones where its estimates are reliable. © 2016. American Geophysical Union.

  14. Fuel Class Higher Alcohols

    KAUST Repository

    Sarathy, Mani

    2016-08-17

    This chapter focuses on the production and combustion of alcohol fuels with four or more carbon atoms, which we classify as higher alcohols. It assesses the feasibility of utilizing various C4-C8 alcohols as fuels for internal combustion engines. Utilizing higher-molecular-weight alcohols as fuels requires careful analysis of their fuel properties. ASTM standards provide fuel property requirements for spark-ignition (SI) and compression-ignition (CI) engines such as the stability, lubricity, viscosity, and cold filter plugging point (CFPP) properties of blends of higher alcohols. Important combustion properties that are studied include laminar and turbulent flame speeds, flame blowout/extinction limits, ignition delay under various mixing conditions, and gas-phase and particulate emissions. The chapter focuses on the combustion of higher alcohols in reciprocating SI and CI engines and discusses higher alcohol performance in SI and CI engines. Finally, the chapter identifies the sources, production pathways, and technologies currently being pursued for production of some fuels, including n-butanol, iso-butanol, and n-octanol.

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

    Science.gov (United States)

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

    2017-02-01

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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Carotid and vertebral artery sacrifice with a combination of Onyx and coils: technical note and case series.

    Science.gov (United States)

    Chalouhi, Nohra; Starke, Robert M; Tjoumakaris, Stavropoula I; Jabbour, Pascal M; Gonzalez, L Fernando; Hasan, David; Rosenwasser, Robert H; Dumont, Aaron S

    2013-08-01

    Permanent vessel sacrifice has become a routine for the management of aneurysms, pseudoaneurysms, tumors, and carotid blowouts. The purpose of this study is to describe a new technique for carotid and vertebral artery sacrifice using a combination of Onyx and coils and to assess its feasibility, safety, and efficacy. The technique consists of deploying a few coils in the parent vessel under proximal flow arrest followed by Onyx embolization directly into the coil mass. A total of 41 patients underwent carotid/vertebral artery sacrifice using this technique in our institution. A total of 26 internal carotid arteries and 15 vertebral arteries were treated. In all but one patient, a balloon test occlusion was performed prior to permanent arterial sacrifice. The mean number of coils used was 6.8 (range, 2-19). The total volume of Onyx used was 1.3 ml on average (range, 0.2-5.2 ml). All 41 (100%) parent arteries were successfully occluded. No distal migration of Onyx or coils was noted. Periprocedural complications occurred in 14.6% (6/41) of cases causing permanent morbidity in 7.3% (3/41). No patient developed a recurrence during the follow-up period (mean, 14 months). Parent vessel sacrifice with a combination of Onyx and coils appears to be feasible, safe, and effective and may be an alternative to the traditional deconstruction technique with coils alone. The risk of thromboembolism exists with this technique, but there were no instances of Onyx migration.

  1. Sacrifice and extracranial reconstruction of the common or internal carotid artery in advanced head and neck carcinoma: Review and meta-analysis.

    Science.gov (United States)

    Bäck, Leif J J; Aro, Katri; Tapiovaara, Laura; Vikatmaa, Pirkka; de Bree, Remco; Fernández-Álvarez, Verónica; Kowalski, Luiz P; Nixon, Iain J; Rinaldo, Alessandra; Rodrigo, Juan P; Robbins, K Thomas; Silver, Carl E; Snyderman, Carl H; Suárez, Carlos; Takes, Robert P; Ferlito, Alfio

    2018-02-05

    Sacrifice and reconstruction of the carotid artery in cases of head and neck carcinoma with invasion of the common or internal carotid artery is debated. We conducted a systematic search of electronic databases and provide a review and meta-analysis. Of the 72 articles identified, 24 met the inclusion criteria resulting in the inclusion of 357 patients. The overall perioperative 30-day mortality was 3.6% (13/357). Permanent cerebrovascular complications occurred in 3.6% (13/357). Carotid blowout episodes were encountered in 1.4% (5/357). The meta-regression analysis showed a significant difference in 1-year overall survival between reports published from 1981-1999 (37.0%) and 2001-2016 (65.4%; P = .02). This review provides evidence that sacrifice with extracranial reconstruction of common or internal carotid artery in selected patients with head and neck carcinoma may improve survival with acceptable complication rates. However, all of the published literature is retrospective involving selected series and, therefore, precludes determining the absolute effectiveness of the surgery. © 2018 Wiley Periodicals, Inc.

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

    International Nuclear Information System (INIS)

    Gregoire, M.

    2010-01-01

    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.

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

    International Nuclear Information System (INIS)

    Curran, R.

    1997-01-01

    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

  4. Large-scale deposition of weathered oil in the Gulf of Mexico following a deep-water oil spill.

    Science.gov (United States)

    Romero, Isabel C; Toro-Farmer, Gerardo; Diercks, Arne-R; Schwing, Patrick; Muller-Karger, Frank; Murawski, Steven; Hollander, David J

    2017-09-01

    The blowout of the Deepwater Horizon (DWH) drilling rig in 2010 released an unprecedented amount of oil at depth (1,500 m) into the Gulf of Mexico (GoM). Sedimentary geochemical data from an extensive area (∼194,000 km 2 ) was used to characterize the amount, chemical signature, distribution, and extent of the DWH oil deposited on the seafloor in 2010-2011 from coastal to deep-sea areas in the GoM. The analysis of numerous hydrocarbon compounds (N = 158) and sediment cores (N = 2,613) suggests that, 1.9 ± 0.9 × 10 4 metric tons of hydrocarbons (>C9 saturated and aromatic fractions) were deposited in 56% of the studied area, containing 21± 10% (up to 47%) of the total amount of oil discharged and not recovered from the DWH spill. Examination of the spatial trends and chemical diagnostic ratios indicate large deposition of weathered DWH oil in coastal and deep-sea areas and negligible deposition on the continental shelf (behaving as a transition zone in the northern GoM). The large-scale analysis of deposited hydrocarbons following the DWH spill helps understanding the possible long-term fate of the released oil in 2010, including sedimentary transformation processes, redistribution of deposited hydrocarbons, and persistence in the environment as recycled petrocarbon. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. 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.

  6. A review of the major marine environmental concerns off the Canadian East Coast in the 1980s

    International Nuclear Information System (INIS)

    Harding, G.C.

    1992-01-01

    The natural environmental features of the Canadian east coast marine waters are described and anthropogenic influences that affect this environment are reviewed, with extensive reference to the literature. Effects from pollutants such as halogenated and aromatic hydrocarbons, trace metals, and radioactive materials are included, as well as effects from ozone depletion, greenhouse gas emissions, hydroelectric development, dredging and dumping, municipal sewage disposal, and coastal development in general. The most concentrated pollution in the Atlantic region is the St. Lawrence River valley and estuary, although there are a number of smaller sites associated with population centers such as St. John, New Brunswick and Halifax, Nova Scotia. Specific industries located along the coast have polluted local environments more than other activities. Sewage discharges have seriously affected expansion of the aquaculture industry. Hydroelectric development may have altered marine biological production, but more directed research is needed to assess the problem. Offshore exploration for oil and gas has had no observed adverse effects on the ecosystem to date, although the possibility for an environmental disaster from a well blowout or marine accident still exists. 177 refs., 3 figs

  7. Effects of Pollution on Marine Organisms.

    Science.gov (United States)

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

    2017-10-01

    This review covers selected 2016 articles on the biological effects of pollutants and human physical disturbances on marine and estuarine plants, animals, ecosystems and habitats. The review, based largely on journal articles, covers field and laboratory measurement activities (bioaccumulation of contaminants, field assessment surveys, toxicity testing and biomarkers) as well as pollution issues of current interest including endocrine disrupters, emerging contaminants, wastewater discharges, dredging and disposal etc. Special emphasis is placed on effects of oil spills and marine debris due largely to the 2010 Deepwater Horizon oil blowout in the Gulf of Mexico. Several topical areas reviewed in the past (ballast water and ocean acidification) were dropped this year. The focus of this review is on effects, not pollutant fate and transport. There is considerable overlap across subject areas (e.g.some bioaccumulation papers may be cited in other topical categories). Please use keyword searching of the text to locate related but distributed papers. Use this review only as a guide and please consult the original papers before citing them.

  8. Equivalent Circulation Density Analysis of Geothermal Well by Coupling Temperature

    Directory of Open Access Journals (Sweden)

    Xiuhua Zheng

    2017-02-01

    Full Text Available The accurate control of the wellbore pressure not only prevents lost circulation/blowout and fracturing formation by managing the density of the drilling fluid, but also improves productivity by mitigating reservoir damage. Calculating the geothermal pressure of a geothermal well by constant parameters would easily bring big errors, as the changes of physical, rheological and thermal properties of drilling fluids with temperature are neglected. This paper researched the wellbore pressure coupling by calculating the temperature distribution with the existing model, fitting the rule of density of the drilling fluid with the temperature and establishing mathematical models to simulate the wellbore pressures, which are expressed as the variation of Equivalent Circulating Density (ECD under different conditions. With this method, the temperature and ECDs in the wellbore of the first medium-deep geothermal well, ZK212 Yangyi Geothermal Field in Tibet, were determined, and the sensitivity analysis was simulated by assumed parameters, i.e., the circulating time, flow rate, geothermal gradient, diameters of the wellbore, rheological models and regimes. The results indicated that the geothermal gradient and flow rate were the most influential parameters on the temperature and ECD distribution, and additives added in the drilling fluid should be added carefully as they change the properties of the drilling fluid and induce the redistribution of temperature. To ensure the safe drilling and velocity of pipes tripping into the hole, the depth and diameter of the wellbore are considered to control the surge pressure.

  9. Influence of petroleum deposit geometry on local gradient of electron acceptors and microbial catabolic potential.

    Science.gov (United States)

    Singh, Gargi; Pruden, Amy; Widdowson, Mark A

    2012-06-05

    A field survey was conducted following the Deepwater Horizon blowout and it was noted that resulting coastal petroleum deposits possessed distinct geometries, ranging from small tar balls to expansive horizontal oil sheets. A subsequent laboratory study evaluated the effect of oil deposit geometry on localized gradients of electron acceptors and microbial community composition, factors that are critical to accurately estimating biodegradation rates. One-dimensional top-flow sand columns with 12-h simulated tidal cycles compared two contrasting geometries (isolated tar "balls" versus horizontal "sheets") relative to an oil-free control. Significant differences in the effluent dissolved oxygen and sulfate concentrations were noted among the columns, indicating presence of anaerobic zones in the oiled columns, particularly in the sheet condition. Furthermore, quantification of genetic markers of terminal electron acceptor and catabolic processes via quantitative polymerase chain reaction of dsrA (sulfate-reduction), mcrA (methanogenesis), and cat23 (oxygenation of aromatics) genes in column cores suggested more extensive anaerobic conditions induced by the sheet relative to the ball geometry. Denaturing gradient gel electrophoresis similarly revealed that distinct gradients of bacterial communities established in response to the different geometries. Thus, petroleum deposit geometry impacts local dominant electron acceptor conditions and may be a key factor for advancing attenuation models and prioritizing cleanup.

  10. 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.

  11. Well Integrity for Natural Gas Storage in Depleted Reservoirs and Aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Freifeld, Barry M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Oldenburg, Curtis M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Jordan, Preston [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Pan, Lehua [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Perfect, Scott [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Morris, Joseph [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); White, Joshua [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bauer, Stephen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Blankenship, Douglas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Roberts, Barry [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bromhal, Grant [National Energy Technology Lab. (NETL), Morgantown, WV (United States); Glosser, Deborah [National Energy Technology Lab. (NETL), Morgantown, WV (United States); Wyatt, Douglas [National Energy Technology Lab. (NETL), Morgantown, WV (United States); Rose, Kelly [National Energy Technology Lab. (NETL), Morgantown, WV (United States)

    2016-09-02

    Introduction Motivation The 2015-2016 Aliso Canyon/Porter Ranch natural gas well blowout emitted approximately 100,000 tonnes of natural gas (mostly methane, CH4) over four months. The blowout impacted thousands of nearby residents, who were displaced from their homes. The high visibility of the event has led to increased scrutiny of the safety of natural gas storage at the Aliso Canyon facility, as well as broader concern for natural gas storage integrity throughout the country. Federal Review of Well Integrity In April of 2016, the U.S. Department of Energy (DOE), in conjunction with the U.S. Department of Transportation (DOT) through the Pipeline and Hazardous Materials Safety Administration (PHMSA), announced the formation of a new Interagency Task Force on Natural Gas Storage Safety. The Task Force enlisted a group of scientists and engineers at the DOE National Laboratories to review the state of well integrity in natural gas storage in the U.S. The overarching objective of the review is to gather, analyze, catalogue, and disseminate information and findings that can lead to improved natural gas storage safety and security and thus reduce the risk of future events. The “Protecting our Infrastructure of Pipelines and Enhancing Safety Act of 2016’’ or the ‘‘PIPES Act of 2016,’’which was signed into law on June 22, 2016, created an Aliso Canyon Natural Gas Leak Task Force led by the Secretary of Energy and consisting of representatives from the DOT, Environmental Protection Agency (EPA), Department of Health and Human Services, Federal Energy Regulatory Commission (FERC), Department of Commerce and the Department of Interior. The Task Force was asked to perform an analysis of the Aliso Canyon event and make recommendations on preventing similar incidents in the future. The PIPES Act also required that DOT/PHMSA promulgate minimum safety standards for underground storage that would take effect within two years. Background on the DOE

  12. 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

  13. 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.

  14. Experimental Study of Hydrogen Addition Effects on a Swirl-Stabilized Methane-Air Flame

    Directory of Open Access Journals (Sweden)

    Mao Li

    2017-11-01

    Full Text Available The effects of H2 addition on a premixed methane-air flame was studied experimentally with a swirl-stabilized gas turbine model combustor. Experiments with 0%, 25%, and 50% H2 molar fraction in the fuel mixture were conducted under atmospheric pressure. The primary objectives are to study the impacts of H2 addition on flame lean blowout (LBO limits, flame shapes and anchored locations, flow field characteristics, precessing vortex core (PVC instability, as well as the CO emission performance. The flame LBO limits were identified by gradually reducing the equivalence ratio until the condition where the flame physically disappeared. The time-averaged CH chemiluminescence was used to reveal the characteristics of flame stabilization, e.g., flame structure and stabilized locations. In addition, the inverse Abel transform was applied to the time-averaged CH results so that the distribution of CH signal on the symmetric plane of the flame was obtained. The particle image velocimetry (PIV was used to detect the characteristics of the flow field with a frequency of 2 kHz. The snapshot method of POD (proper orthogonal decomposition and fast Fourier transform (FFT were adopted to capture the most prominent coherent structures in the turbulent flow field. CO emission was monitored with an exhaust probe that was installed close to the combustor exit. The experimental results indicated that the H2 addition extended the flame LBO limits and the operation range of low CO emission. The influence of H2 addition on the flame shape, location, and flow field was observed. With the assistance of POD and FFT, the combustion suppression impacts on PVC was found.

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

    International Nuclear Information System (INIS)

    Reschke, D. N.; Campbell, L. M.

    1999-01-01

    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

  16. Using a global ocean circulation model to conduct a preliminary risk assessment of oil spills in the Atlantic

    Science.gov (United States)

    Jacobs, Zoe; Popova, Katya; Hirschi, Joel; Coward, Andrew; Yool, Andrew; van Gennip, Simon; Anifowose, Babtunde; Harrington-Missin, Liam

    2017-04-01

    Although oil blowouts from deep-water drilling happen very rarely, they can cause catastrophic damage to the environment. Despite such potentially high impacts, relatively little research effort has gone into understanding subsurface oil plumes in the deep ocean. In this study, we demonstrate the significance of this problem and offer potential solutions using a novel approach based on a leading-edge, high-resolution global ocean circulation model. We present examples demonstrating: (a) the importance of ocean circulation in the propagation of oil spills; and (b) likely circulation footprints for oil spills at four key locations in the Atlantic Ocean that exist in different circulation regimes - the shelves of Brazil, the Gulf of Guinea, the Gulf of Mexico and the Faroe-Shetland Channel. In order to quantify the variability at each site on seasonal timescales, interannual timescales and at different depths, we utilize the Modified Hausdorff Distance (MHD), which is a shape-distance metric that measures the similarity between two shapes. The scale of the footprints across the four focus locations varies considerably and is determined by the main circulation features in their vicinity. For example, the hypothetical oil plume can be affected by variations in the speed and location of a particular current (e.g. Brazil Current at the Brazilian shelf site) or be influenced by different currents entirely depending on the release depth, month and year (e.g. Angola Current or Southern Equatorial Current at the Gulf of Guinea site). Overall, our results demonstrate the need to use state of the art global, or basin-scale, ocean circulation models when assessing the environmental impacts of proposed oil drilling activities.

  17. Frontal Dynamics of Powder Snow Avalanches

    Science.gov (United States)

    Louge, M. Y.; Carroll, C. S.; Turnbull, B.

    2012-04-01

    We model the dynamics of the head of dilute powder snow avalanches sustained by a massive frontal blow-out, arising as a weakly cohesive snow cover is fluidized by the very pore pressure gradients that the avalanche induces within the snow pack. Such material eruption just behind the front acts as a source of denser fluid thrust into a uniform ambient air flow at high Reynolds number. In such "eruption current", fluidization depth is inversely proportional to a bulk Richardson number representing avalanche height. By excluding situations in which the snow cover is not fluidized up to its free surface, we derive a criterion combining snow pack friction and density indicating which avalanches can produce a sustainable powder cloud. A mass balance involving snow cover and powder cloud sets avalanche height and mean density. By determining which solution of the mass balance is stable, we find that avalanches reach constant growth and acceleration rates for fixed slope and avalanche width. Under these conditions, we calculate the fraction of the fluidized cover that is actually scoured and blown-out into the cloud, and deduce from a momentum balance on the head that the avalanche accelerates at a rate only 14% of the gravitational component along the flow. We also calculate how far a powder cloud travels until its mean density becomes constant. Finally, we show that the dynamics of powder snow avalanches are crucially affected by the rate of change of their width, for example by reaching an apparent steady speed as their channel widens. If such widening is rapid, or if slope inclination vanishes, we calculate where and how powder clouds collapse. Predictions agree well with observations of powder snow avalanches carried out at the Vallee de la Sionne (Switzerland).

  18. 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). Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Hyperfractionated stereotactic reirradiation for recurrent head and neck cancer

    International Nuclear Information System (INIS)

    Cvek, Jakub; Knybel, Lukas; Skacelikova, Eva; Otahal, Bretislav; Molenda, Lukas; Feltl, David; Stransky, Jiri; Res, Oldrich; Matousek, Petr; Zelenik, Karol

    2016-01-01

    The goal of this work was to evaluate the efficacy and toxicity of hyperfractionated stereotactic reirradiation (re-RT) as a treatment for inoperable, recurrent, or second primary head and neck squamous cell cancer (HNSCC) that is not suitable for systemic treatment. Forty patients with recurrent or second primary HNSCC were included in this study. The patients had a median gross tumor volume of 76 ml (range 14-193 ml) and a previous radiotherapy dose greater than 60 Gy. Treatment was designed to cover 95 % of the planning target volume (PTV, defined as gross tumor volume [GTV] + 3 mm to account for microscopic spreading, with no additional set-up margin) with the prescribed dose (48 Gy in 16 fractions b.i.d.). Treatment was administered twice daily with a minimum 6 h gap. Uninvolved lymph nodes were not irradiated. Treatment was completed as planned for all patients (with median duration of 11 days, range 9-14 days). Acute toxicity was evaluated using the RTOG/EORTC scale. A 37 % incidence of grade 3 mucositis was observed, with recovery time of ≤ 4 weeks for all of these patients. Acute skin toxicity was never observed to be higher than grade 2. Late toxicity was also evaluated according to the RTOG/EORTC scale. Mandible radionecrosis was seen in 4 cases (10 %); however, neither carotid blowout syndrome nor other grade 4 late toxicity occurred. One-year overall survival (OS) and local progression-free survival (L-PFS) were found to be 33 and 44 %, respectively. Performance status and GTV proved to be significant prognostic factors regarding local control and survival. Hyperfractionated stereotactic re-RT is a reasonable treatment option for patients with recurrent/second primary HNSCC who were previously exposed to high-dose irradiation and who are not candidates for systemic treatment or hypofractionation. (orig.) [de

  20. Hydrocarbon-Degrading Bacteria Exhibit a Species-Specific Response to Dispersed Oil while Moderating Ecotoxicity.

    Science.gov (United States)

    Overholt, Will A; Marks, Kala P; Romero, Isabel C; Hollander, David J; Snell, Terry W; Kostka, Joel E

    2016-01-15

    The Deepwater Horizon blowout in April 2010 represented the largest accidental marine oil spill and the largest release of chemical dispersants into the environment to date. While dispersant application may provide numerous benefits to oil spill response efforts, the impacts of dispersants and potential synergistic effects with crude oil on individual hydrocarbon-degrading bacteria are poorly understood. In this study, two environmentally relevant species of hydrocarbon-degrading bacteria were utilized to quantify the response to Macondo crude oil and Corexit 9500A-dispersed oil in terms of bacterial growth and oil degradation potential. In addition, specific hydrocarbon compounds were quantified in the dissolved phase of the medium and linked to ecotoxicity using a U.S. Environmental Protection Agency (EPA)-approved rotifer assay. Bacterial treatment significantly and drastically reduced the toxicity associated with dispersed oil (increasing the 50% lethal concentration [LC50] by 215%). The growth and crude oil degradation potential of Acinetobacter were inhibited by Corexit by 34% and 40%, respectively; conversely, Corexit significantly enhanced the growth of Alcanivorax by 10% relative to that in undispersed oil. Furthermore, both bacterial strains were shown to grow with Corexit as the sole carbon and energy source. Hydrocarbon-degrading bacterial species demonstrate a unique response to dispersed oil compared to their response to crude oil, with potentially opposing effects on toxicity. While some species have the potential to enhance the toxicity of crude oil by producing biosurfactants, the same bacteria may reduce the toxicity associated with dispersed oil through degradation or sequestration. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  1. 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

  2. Health Impact Assessment of an oil drilling project in California.

    Science.gov (United States)

    McCallum, Lindsay C; Souweine, Kathleen; McDaniel, Mary; Koppe, Bart; McFarland, Christine; Butler, Katherine; Ollson, Christopher A

    2016-01-01

    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). 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). 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. 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. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  3. 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. Copyright © 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  4. 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.

  5. Dune Morphology and Sediment Budget Responses to Varying Vegetation Cover and Restoration: Humboldt Bay National Wildlife Refuge, Northern California.

    Science.gov (United States)

    Rader, A. M.; Walker, I. J.; Pickart, A.

    2016-12-01

    This study examines morphodynamic and sedimentation responses of a stretch of coastal foredune undergoing removal of invasive vegetation (Ammophila arenaria) to restore ecosystem dynamics at Humboldt Bay National Wildlife Refuge. Seasonal topographic and vegetation transect surveys and historical aerial photography are analyzed to assess interannual to decadal geomorphic responses of the foredune and sediment budget changes. Relationships between sedimentation and geomorphic change are explored between dominant vegetation cover types as possible. The foredune maintained a near balanced position (+0.004 m a-1) between 1939 and 2014 across the study site. However, there is a general N to S trend from progradation to retreat of the foredune with a maximum change of +1.34 m a-1 in the northern A. arenaria dominated areas to a max retreat of -0.49 m a-1 in the southern sites with a lower and more hummocky foredune dominated by native plants. From 2004 to 2014, percent active sand surface and average aerial change of blowouts remained relatively stable across the study site, with average change values of -0.97% and +0.01% respectively. Positive statistical correlations exist between seasonal beach and foredune volume changes across all sites, yet no significant differences are observed in total volumetric change over the observation period or volume changes within beach and foredune between different vegetation cover types. Survey and aerial photography results suggest that the increased density of A. arenaria has contributed to foredune stabilization over recent decades. However, there is no observed significant difference in seasonal sand volume change in relation to differing dominant vegetation covers. Rather, strong positive correlations exist between seasonal beach volumes and foredune sedimentation, which suggests that foredune sediment budgets may be driven primarily by littoral and aeolian supply variations. Future research will explore vegetation

  6. Geomicrobiology of Archaeal Communities Isolated from an Off-axis Abyssal Hill Fault Scarp on the East Pacific Rise Flank at 9° 27'N

    Science.gov (United States)

    Ehrhardt, C. J.; Haymon, R.; Holden, P.; Lamontagne, M.

    2003-12-01

    Although heat flow studies suggest that ~70% of the hydrothermal heat loss in the oceans occurs in the abyssal hill terrain on the flanks of mid-ocean ridges, very few off-axis hydrothermal sites have been discovered. In May 2002, sedimentary blowout structures of probable hydrothermal origin were discovered along East Pacific Rise at 9° 27'N on an off-axis abyssal hill bounded by a fault scarp covered with orange-brown microbial flocculations. Recovered samples of these flocculations have presented an opportunity to study the unknown nature and role of thermophilic and hyperthermophilic microbial communities on the ridge flanks. Furthermore, the archaeal communities that we have identified in the samples are useful "microbial tracers" which can be used to locate off-axis areas of moderate-to-high temperature fluid flow (>50° C). In this study, we used molecular techniques to isolate, amplify, and sequence community archaeal RNA sequences from fault scarp flocculations collected with a slurp pump system mounted in the Alvin basket. Molecular phylogenies based on 16S rRNA were constructed. Phylogenetic relationships of isolated clones were used to infer temperature preferences of archaeal communities. We identified 12 clones that clustered within thermophilic or hyperthermophilic clades within Archaea suggesting that moderately high temperature fluid (>50° C) exited the seafloor along this abyssal hill fault scarp. Our studies also suggest that these communities mediate the formation of Fe-sulfide mineral phases. Analysis of the samples with an Environmental Scanning Electron Microscope (ESEM) and X-ray energy dispersive analysis (EDS) revealed unique iron sulfide mineral phases with anomalously low Fe/S ratios in direct association with microbial communities.

  7. Practice patterns in the use of prophylactic antibiotics following nonoperative orbital fractures

    Directory of Open Access Journals (Sweden)

    Wang JJ

    2016-10-01

    Full Text Available Jijo Jizhou Wang,1 Jennifer M Koterwas,2 Edward H Bedrossian Jr,2 William J Foster2,3 1Lewis Katz School of Medicine, 2Department of Ophthalmology, Lewis Katz School of Medicine, 3Department of Bioengineering, College of Engineering, Temple University, Philadelphia, PA, USA Purpose: The purpose of this study was to analyze the practice management patterns of the current members of the American Society of Ophthalmic Plastic and Reconstructive Surgery (ASOPRS and to determine the use of oral prophylactic antibiotics in an attempt to prevent orbital cellulitis following nonoperative orbital fractures.Patients and methods: A cross-sectional web-based survey was emailed to all the members of ASOPRS regarding their current management of nonsurgical orbital fractures and their experience with orbital cellulitis following nonoperative orbital fractures.Results: The majority of practicing oculoplastic surgeon members of ASOPRS do not routinely prescribe prophylactic antibiotics for patients with nonoperative orbital fractures or patients with orbital fractures whom the physicians are observing and who might potentially need surgical intervention. Among the reported cases of orbital cellulitis following a nonoperative orbital fracture in this survey, more than a quarter of the patients had received prophylactic antibiotics. Furthermore, among physicians who have managed orbital cellulitis following nonoperative fracture, 75% (33 out of 44 physicians report that <1% of patients develop orbital cellulitis.Conclusion: Despite frequent recommendation for the use of prophylactic antibiotics after orbital fractures in commonly cited ophthalmic references, the majority of oculoplastic surgeons do not use prophylactic antibiotics for orbital fractures, including both nonoperative orbital fractures and orbital fractures that may potentially need surgery. Keywords: orbital blowout fracture, orbital fracture, antibiotic use, practice patterns, survey

  8. 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.

  9. Parabolic dune reactivation and migration at Napeague, NY, USA: Insights from aerial and GPR imagery

    Science.gov (United States)

    Girardi, James D.; Davis, Dan M.

    2010-02-01

    Observations from mapping since the 19th century and aerial imagery since 1930 have been used to study changes in the aeolian geomorphology of coastal parabolic dunes over the last ~ 170 years in the Walking Dune Field, Napeague, NY. The five large parabolic dunes of the Walking Dune Field have all migrated across, or are presently interacting with, a variably forested area that has affected their migration, stabilization and morphology. This study has concentrated on a dune with a particularly complex history of stabilization, reactivation and migration. We have correlated that dune's surface evolution, as revealed by aerial imagery, with its internal structures imaged using 200 MHz and 500 MHz Ground Penetrating Radar (GPR) surveys. Both 2D (transect) and high-resolution 3D GPR imagery image downwind dipping bedding planes which can be grouped by apparent dip angle into several discrete packages of beds that reflect distinct decadal-scale episodes of dune reactivation and growth. From aerial and high resolution GPR imagery, we document a unique mode of reactivation and migration linked to upwind dune formation and parabolic dune interactions with forest trees. This study documents how dune-dune and dune-vegetation interactions have influenced a unique mode of blowout deposition that has alternated on a decadal scale between opposite sides of a parabolic dune during reactivation and migration. The pattern of recent parabolic dune reactivation and migration in the Walking Dune Field appears to be somewhat more complex, and perhaps more sensitive to subtle environmental pressures, than an idealized growth model with uniform deposition and purely on-axis migration. This pattern, believed to be prevalent among other parabolic dunes in the Walking Dune Field, may occur also in many other places where similar observational constraints are unavailable.

  10. 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.

  11. An Australian government dental scheme: Doctor-dentist-patient tensions in the triangle.

    Science.gov (United States)

    Weerakoon, Arosha; Fitzgerald, Lisa; Porter, Suzette

    2014-11-30

    Autonomy of participants is challenged when legislation to provide a public health service is weakly designed and implemented. Australia's Chronic Disease Dental Scheme was instigated to provide a government subsidy for private dental treatment for people suffering chronic illness impacting their oral health or vice versa. They were allocated AUD$4250 towards comprehensive treatment over 2 years with their eligibility determined by their general medical doctor. A qualitative research study was conducted to explore the experiences from the perspectives of the patient, medical and dental practitioner. One of the research outcomes identified a frequently reported level of discomfort in the patient/doctor/dentist triangle. Doctors and dentists reported feeling forced by patients into positions that compromised their autonomy in obeying the intent (if not the law) of the scheme. Additionally, dentists felt under pressure from doctors and patients to provide subsidized treatment to those eligible. In turn, the patients reported difficulties in gaining access to the scheme and in some cases, experiencing full or partially unmet oral health needs. REASON FOR CONFLICT: Poor inter-professional communication and lack of understanding about profession-unique patient-driven pressures, ultimately contributed to dissonance. Ill-defined eligibility guidelines rendered the doctor's ability to gate-keep challenging. OUTCOME OF CONFLICT: Inefficient gate-keeping led to exponential increase in referrals, resulting in unprecedented cost blow-outs. Ensuing government-led audits caused political tensions and contributed to the media-induced vilification of dentists. In December 2013, government financing of dental treatment through Chronic Disease Dental Scheme was discontinued, leaving many Australians without a viable alternative. There is a need for qualitative research methods to help identify social issues that affect public health policy process. In order to succeed, new health

  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. 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.

  14. Prognostic Factors of Orbital Fractures with Muscle Incarceration

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    Seung Chan Lee

    2017-09-01

    Full Text Available Background Among the various signs and symptoms of orbital fractures, certain clinical findings warrant immediate surgical exploration, including gaze restriction, computed tomographic (CT evidence of entrapment, and prolonged oculocardiac reflex. Despite proper surgical reconstruction, prolonged complications such as diplopia and gaze restriction can occur. This article evaluated the prognostic factors associated with prolonged complications of orbital fractures with muscle incarceration. Methods The medical records of 37 patients (37 orbits with an orbital fracture with muscle incarceration from January 2001 to January 2015 were reviewed. The presence of Incarcerated muscle was confirmed via CT, as well as by intraoperative findings. Various factors potentially contributing to complications lasting for over 1 year after the injury were categorized and analyzed, including age, cause of injury, injury-to-operation time, operative time, fracture type, nausea, vomiting and other concomitant symptoms and injuries. Results All patients who presented with extraocular muscle limitations, positive CT findings, and/or a positive forced duction test underwent surgery. Of the 37 patients, 9 (24% exhibited lasting complications, such as diplopia and gaze restriction. The mean follow-up period was 18.4 months (range, 1–108 months, while that of patients who experienced prolonged complications was 30.1 months (range, 13–36 months. Two factors were significantly associated with prolonged complications: injury-to-operation time and nausea/vomiting. Loss of vision, worsening of motility, and implant complication did not occur. Conclusions Patients who present with gaze limitations, with or without other signs of a blow-out fracture, require a thorough evaluation and emergent surgery. A better prognosis is expected with a shorter injury-to-operation time and lack of nausea and vomiting at the initial presentation.

  15. Research of mining and geological conditions for geological exploration in Pre-Caucasian region

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    Р. А. Гасумов

    2017-12-01

    Full Text Available Taking into consideration natural depletion of reserves of hydrocarbons in Mesozoic deposits of the majority of operated deposits of North Caucasus and for the purpose of further development of oil and gas producing industry in the region it is necessary to involve a carbonaceous complex of Jura of West Pre-Caucasus with the burial depth of more than 5300 m in the development. When drafting engineering design for a construction of exploratory wells in complex mining and geological conditions driven by anomalously high overburden pressure and temperature, use of thoroughly studied field geological information and taking into consideration the experience of boring similar wells is important. The paper provides analysis of geophysical data, the results of complex studies of reservoir porosity and permeability features of rocks picked out of core-samples of the first exploratory well on Krupskaya zone (porosity, permeability, electrical, acoustic, lithological characteristics, pressure-and-temperature conditions. The information obtained allowed to specify technological parameters of boring and tailing-in and to give recommendations regarding the way of exploratory wells boring and use of borehole equipment. In order to avoid the development of significant hydrodynamic pressure in the borehole which provokes gas showings it is necessary to keep on a certain level of minimal values of mud rheology parameters (dynamic shear stress τ = 70¸135 dPa; plastic viscosity η = 25¸35 mPa·s. For the purpose of real-time keeping of overbalance with anomalously high overburden pressure, control and regulation of calculated head pressure a stripper head should be included into the equipment configuration. Furthermore well head equipment and blowout preventer equipment must be designed for expected gradient of overburden pressure.

  16. Ocular Blood Flow Measurements in Healthy White Subjects Using Laser Speckle Flowgraphy.

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    Nikolaus Luft

    Full Text Available To assess the feasibility and reliability of Laser Speckle Flowgraphy (LSFG to measure ocular perfusion in a sample of healthy white subjects and to elucidate the age-dependence of the parameters obtained.This cross-sectional study included 80 eyes of 80 healthy, non-smoking white subjects of Western European descent between 19 and 79 years of age. A commercial LSFG instrument was applied to measure ocular blood flow at the optic nerve head (ONH three successive times before and after pharmacological pupil dilation. The mean blur rate (MBR, a measure of relative blood flow velocity, was obtained for different regions of the ONH. Eight parameters of ocular perfusion derived from the pulse-waveform analysis of MBR including blowout time (BOT and falling rate (FR were also recorded.Artifact-free LSFG images meeting the quality criteria for automated image analysis were obtainable in 93.8% without pupil dilation and in 98.8% with pharmacological pupil dilation. Measurements of MBR showed excellent repeatability with intraclass correlation coefficients ≥ 0.937 and were barely affected by pupil dilation. The majority of pulse-waveform derived variables exhibited equally high repeatability. MBR-related blood flow indices exhibited significant age dependence (p<0.001. FR (r = 0.747, p<0.001 and BOT (r = -0.714, p<0.001 most strongly correlated with age.LSFG represents a reliable method for the quantitative assessment of ocular blood flow in white subjects. Our data affirms that the LSFG-derived variables FR and BOT may be useful biomarkers for age-related changes in ocular perfusion.

  17. Longitudinal changes of ocular blood flow using laser speckle flowgraphy during normal pregnancy.

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    Takahiro Sato

    Full Text Available Innovative laser speckle flowgraphy (LSFG enables noninvasive evaluation of retinal microcirculation and the usefulness has been reported in the field of ophthalmology. LSFG has allowed us to measure the real time changes of retinal blood flow without pupillary dilatations and contrast media. Herein, we investigated the change of retinal blood flow in normal pregnant women during gestation using LSFG.A prospective cohort study was conducted in 53 pregnant women who visited our institution between January, 2013 and July, 2014. Finally, a total of 41 participants without any obstetric complications were available for evaluation. Retinal blood flow was measured with LSFG in a total of 4 times during pregnancy (T1. 11-13 weeks, T2. 19-21 weeks, T3. 28-30 weeks, T4. 34-36 weeks and mean blur rate (MBR, blowout score (BOS, flow acceleration index (FAI, and resistive index (RI are analyzed from these measurements. Relations between LSFG parameters and mean arterial blood pressure (MAP are determined throughout pregnancy.MBR showed no significant changes throughout pregnancy. BOS showed a tendency to increase in the 3rd trimester. FAI values showed a slight increase from the 1st to 2nd trimester while a significant decrease was noted in the 3rd trimester. RI exhibited no changes between the 1st and 2nd trimesters, values decreased significantly after the 3rd trimester. MAP was positively correlated with BOS, and negatively correlated with FAI and RI.The present study clearly demonstrated that profiles of LSFG parameters demonstrated a decrease of resistance in retinal blood vessels. These changes in indices provide a highly sensitive reflection of physiological changes in vascular resistance due to pregnancy. Thus, LSFG may be useful, as a non-invasive, diagnostic tool to detect pregnancy related disorders such as preeclampsia.

  18. Botulinum toxin A for oral cavity cancer patients: in microsurgical patients BTX injections in major salivary glands temporarily reduce salivary production and the risk of local complications related to saliva stagnation.

    Science.gov (United States)

    Corradino, Bartolo; Di Lorenzo, Sara; Moschella, Francesco

    2012-10-24

    In patients suffering from oral cavity cancer surgical treatment is complex because it is necessary to remove carcinoma and lymph node metastasis (through a radical unilateral or bilateral neck dissection) and to reconstruct the affected area by means of free flaps. The saliva stagnation in the post-operative period is a risk factor with regard to local complications. Minor complications related to saliva stagnation (such as tissue maceration and wound dehiscence) could become major complications compromising the surgery or the reconstructive outcome. In fact the formation of oro-cutaneous fistula may cause infection, failure of the free flap, or the patient’s death with carotid blow-out syndrome. Botulinum injections in the major salivary glands, four days before surgery, temporarily reduces salivation during the healing stage and thus could reduce the incidence of saliva-related complications. Forty three patients with oral cancer were treated with botulinum toxin A. The saliva quantitative measurement and the sialoscintigraphy were performed before and after infiltrations of botulinum toxin in the major salivary glands. In all cases there was a considerable, but temporary, reduction of salivary secretion. A lower rate of local complications was observed in the post-operative period. The salivary production returned to normal within two months, with minimal side effects and discomfort for the patients. The temporary inhibition of salivary secretion in the post-operative period could enable a reduction in saliva-related local complications, in the incidence of oro-cutaneous fistulas, and improve the outcome of the surgery as well as the quality of residual life in these patients.

  19. Seismic attributes and advanced computer algorithm to predict formation pore pressure: Qalibah formation of Northwest Saudi Arabia

    Science.gov (United States)

    Nour, Abdoulshakour M.

    Oil and gas exploration professionals have long recognized the importance of predicting pore pressure before drilling wells. Pre-drill pore pressure estimation not only helps with drilling wells safely but also aids in the determination of formation fluids migration and seal integrity. With respect to the hydrocarbon reservoirs, the appropriate drilling mud weight is directly related to the estimated pore pressure in the formation. If the mud weight is lower than the formation pressure, a blowout may occur, and conversely, if it is higher than the formation pressure, the formation may suffer irreparable damage due to the invasion of drilling fluids into the formation. A simple definition of pore pressure is the pressure of the pore fluids in excess of the hydrostatic pressure. In this thesis, I investigated the utility of advance computer algorithm called Support Vector Machine (SVM) to learn the pattern of high pore pressure regime, using seismic attributes such as Instantaneous phase, t*Attenuation, Cosine of Phase, Vp/Vs ratio, P-Impedance, Reflection Acoustic Impedance, Dominant frequency and one well attribute (Mud-Weigh) as the learning dataset. I applied this technique to the over pressured Qalibah formation of Northwest Saudi Arabia. The results of my research revealed that in the Qalibah formation of Northwest Saudi Arabia, the pore pressure trend can be predicted using SVM with seismic and well attributes as the learning dataset. I was able to show the pore pressure trend at any given point within the geographical extent of the 3D seismic data from which the seismic attributes were derived. In addition, my results surprisingly showed the subtle variation of pressure within the thick succession of shale units of the Qalibah formation.

  20. CHARACTERIZATION OF THE INNER DISK AROUND HD 141569 A FROM KECK/NIRC2 L-BAND VORTEX CORONAGRAPHY

    Energy Technology Data Exchange (ETDEWEB)

    Mawet, Dimitri; Bottom, Michael; Matthews, Keith [Department of Astronomy, California Institute of Technology, 1200 East California Boulevard, MC 249-17, Pasadena, CA 91125 (United States); Choquet, Élodie; Serabyn, Eugene [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Absil, Olivier; Huby, Elsa; Gonzalez, Carlos A. Gomez; Wertz, Olivier; Carlomagno, Brunella; Christiaens, Valentin; Defrère, Denis; Delacroix, Christian; Habraken, Serge; Jolivet, Aissa [Space sciences, Technologies and Astrophysics Research (STAR) Institute, Université de Liège, 19 Allée du Six Août, B-4000 Liège (Belgium); Femenia, Bruno [W. M. Keck Observatory, 65-1120 Mamalahoa Hwy., Kamuela, HI 96743 (United States); Lebreton, Jérémy [NASA Exoplanet Science Institute, California Institute of Technology, 770 South Wilson Avenue, Pasadena, CA 91125 (United States); Forsberg, Pontus; Karlsson, Mikael [Department of Engineering Sciences, Ångström Laboratory, Uppsala University, Box 534, SE-751 21 Uppsala (Sweden); Milli, Julien, E-mail: dmawet@astro.caltech.edu [European Southern Observatory, Alonso de Cordóva 3107, Vitacura, Santiago (Chile); and others

    2017-01-01

    HD 141569 A is a pre-main sequence B9.5 Ve star surrounded by a prominent and complex circumstellar disk, likely still in a transition stage from protoplanetary to debris disk phase. Here, we present a new image of the third inner disk component of HD 141569 A made in the L ′ band (3.8 μ m) during the commissioning of the vector vortex coronagraph that has recently been installed in the near-infrared imager and spectrograph NIRC2 behind the W.M. Keck Observatory Keck II adaptive optics system. We used reference point-spread function subtraction, which reveals the innermost disk component from the inner working distance of ≃23 au and up to ≃70 au. The spatial scale of our detection roughly corresponds to the optical and near-infrared scattered light, thermal Q , N , and 8.6 μ m PAH emission reported earlier. We also see an outward progression in dust location from the L ′ band to the H band (Very Large Telescope/SPHERE image) to the visible ( Hubble Space Telescope ( HST )/STIS image), which is likely indicative of dust blowout. The warm disk component is nested deep inside the two outer belts imaged by HST-NICMOS in 1999 (at 406 and 245 au, respectively). We fit our new L ′-band image and spectral energy distribution of HD 141569 A with the radiative transfer code MCFOST. Our best-fit models favor pure olivine grains and are consistent with the composition of the outer belts. While our image shows a putative very faint point-like clump or source embedded in the inner disk, we did not detect any true companion within the gap between the inner disk and the first outer ring, at a sensitivity of a few Jupiter masses.

  1. Drilling into an active mofette: pilot-hole study of the impact of CO2-rich mantle-derived fluids on the geo–bio interaction in the western Eger Rift (Czech Republic

    Directory of Open Access Journals (Sweden)

    R. Bussert

    2017-11-01

    Full Text Available Microbial life in the continental deep biosphere is closely linked to geodynamic processes, yet this interaction is poorly studied. The Cheb Basin in the western Eger Rift (Czech Republic is an ideal place for such a study because it displays almost permanent seismic activity along active faults with earthquake swarms up to ML 4.5 and intense degassing of mantle-derived CO2 in conduits that show up at the surface in form of mofettes. We hypothesize that microbial life is significantly accelerated in active fault zones and in CO2 conduits, due to increased fluid and substrate flow. To test this hypothesis, pilot hole HJB-1 was drilled in spring 2016 at the major mofette of the Hartoušov mofette field, after extensive pre-drill surveys to optimize the well location. After drilling through a thin caprock-like structure at 78.5 m, a CO2 blowout occurred indicating a CO2 reservoir in the underlying sandy clay. A pumping test revealed the presence of mineral water dominated by Na+, Ca2+, HCO3−, SO42− (Na-Ca-HCO3-SO4 type having a temperature of 18.6 °C and a conductivity of 6760 µS cm−1. The high content of sulfate (1470 mg L−1 is typical of Carlsbad Spa mineral waters. The hole penetrated about 90 m of Cenozoic sediments and reached a final depth of 108.50 m in Palaeozoic schists. Core recovery was about 85 %. The cored sediments are mudstones with minor carbonates, sandstones and lignite coals that were deposited in a lacustrine environment. Deformation structures and alteration features are abundant in the core. Ongoing studies will show if they result from the flow of CO2-rich fluids or not.

  2. A study of sports-related orbital fractures in Singapore.

    Science.gov (United States)

    Lock, Jing Zhan; Hegde, Raghuraj; Young, Stephanie; Lim, Thiam Chye; Amrith, Shantha; Sundar, Gangadhara

    2017-10-01

    With an increased popularity of sport and active living worldwide, our study aims to explore the incidence and features of sports-related orbital fractures in Singapore. 1421 computer tomography (CT) imaging scans of the face and orbits done at the National University Hospital over a 24-month period from January 2013 and December 2014 were reviewed retrospectively for orbital fractures. We identified 483 orbital fractures of which sports injury was the fourth most common etiology (n = 65; 13.5%) after road traffic accident (n = 131; 27.1%), geriatric fall (n = 81; 16.8%) and workplace injury (n = 67; 13.9%). The three most common sport in orbital fractures were soccer (n = 20; 30.8%), bicycling (n = 11; 16.9%) and jogging (n = 8; 12.3%). The three most common fracture patterns were zygomatico-maxillary complex fractures (n = 24; 36.9%), isolated one wall blowout fractures (n = 19; 29.2%) and naso-orbito-ethmoid fractures (n = 7; 10.8%). Sports-related orbital fractures were associated with a low mean age of patients (45.9 years, range, 14-79 years), a higher proportion of males (n = 58; 89.2%) than that from geriatric falls (n = 37, 45.6%) (P Sports-related orbital fractures are the fourth most common cause of orbital fractures. Though commonly seen in young male adults, in view of the aging population and people exercising more regularly, education of safety measures among sports users is paramount to preventing sports-related orbital fractures.

  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. 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

  5. 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.

  6. 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.

  7. 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

  8. Fire and grazing effects on wind erosion, soil water content, and soil temperature.

    Science.gov (United States)

    Vermeire, Lance T; Wester, David B; Mitchell, Robert B; Fuhlendorf, Samuel D

    2005-01-01

    Selective grazing of burned patches can be intense if animal distribution is not controlled and may compound the independent effects of fire and grazing on soil characteristics. Our objectives were to quantify the effects of patch burning and grazing on wind erosion, soil water content, and soil temperature in sand sagebrush (Artemisia filifolia Torr.) mixed prairie. We selected 24, 4-ha plots near Woodward, OK. Four plots were burned during autumn (mid-November) and four during spring (mid-April), and four served as nonburned controls for each of two years. Cattle were given unrestricted access (April-September) to burned patches (erosion, soil water content, and soil temperature were measured monthly. Wind erosion varied by burn, year, and sampling height. Wind erosion was about 2 to 48 times greater on autumn-burned plots than nonburned plots during the dormant period (December-April). Growing-season (April-August) erosion was greatest during spring. Erosion of spring-burned sites was double that of nonburned sites both years. Growing-season erosion from autumn-burned sites was similar to nonburned sites except for one year with a dry April-May. Soil water content was unaffected by patch burn treatments. Soils of burned plots were 1 to 3 degrees C warmer than those of nonburned plots, based on mid-day measurements. Lower water holding and deep percolation capacity of sandy soils probably moderated effects on soil water content and soil temperature. Despite poor growing conditions following fire and heavy selective grazing of burned patches, no blowouts or drifts were observed.

  9. 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

  10. Drilling into an active mofette: pilot-hole study of the impact of CO2-rich mantle-derived fluids on the geo-bio interaction in the western Eger Rift (Czech Republic)

    Science.gov (United States)

    Bussert, Robert; Kämpf, Horst; Flechsig, Christina; Hesse, Katja; Nickschick, Tobias; Liu, Qi; Umlauft, Josefine; Vylita, Tomáš; Wagner, Dirk; Wonik, Thomas; Estrella Flores, Hortencia; Alawi, Mashal

    2017-11-01

    Microbial life in the continental deep biosphere is closely linked to geodynamic processes, yet this interaction is poorly studied. The Cheb Basin in the western Eger Rift (Czech Republic) is an ideal place for such a study because it displays almost permanent seismic activity along active faults with earthquake swarms up to ML 4.5 and intense degassing of mantle-derived CO2 in conduits that show up at the surface in form of mofettes. We hypothesize that microbial life is significantly accelerated in active fault zones and in CO2 conduits, due to increased fluid and substrate flow. To test this hypothesis, pilot hole HJB-1 was drilled in spring 2016 at the major mofette of the Hartoušov mofette field, after extensive pre-drill surveys to optimize the well location. After drilling through a thin caprock-like structure at 78.5 m, a CO2 blowout occurred indicating a CO2 reservoir in the underlying sandy clay. A pumping test revealed the presence of mineral water dominated by Na+, Ca2+, HCO3-, SO42- (Na-Ca-HCO3-SO4 type) having a temperature of 18.6 °C and a conductivity of 6760 µS cm-1. The high content of sulfate (1470 mg L-1) is typical of Carlsbad Spa mineral waters. The hole penetrated about 90 m of Cenozoic sediments and reached a final depth of 108.50 m in Palaeozoic schists. Core recovery was about 85 %. The cored sediments are mudstones with minor carbonates, sandstones and lignite coals that were deposited in a lacustrine environment. Deformation structures and alteration features are abundant in the core. Ongoing studies will show if they result from the flow of CO2-rich fluids or not.

  11. Cutaneous Complications Related to Tattoos: 31 Cases from Finland.

    Science.gov (United States)

    Kluger, Nicolas

    2017-01-01

    Cutaneous complications related to permanent tattoos affect 2-30% of those patients who have tattooed their skin. Little is known about the cases of tattoo complications in Finland. The aim of this study was to conduct a retrospective review of a series of Finnish patients with cutaneous tattoo reactions. We collected cases of tattoo reactions from the Department of Dermatology at Helsinki University Central Hospital, from members of the Finnish dermatological society and from various other sources (author's private practice, tattooists, professional internet forum). We analysed the demographics, clinical presentation, diagnosis, and microscopic findings on the skin biopsies, and evaluated the therapeutic outcome. Thirty-one patients (16 men and 15 women, mean age 37.8) were included from 9 cities, mainly from Helsinki. Fifty-two percent (16/31) presented with an allergic tattoo reaction mainly against the red colour (75%, 12/16). Reactions were clinically polymorph ranging from scattered papules or nodules to complete infiltration of a colour. Lesions were itchy and sometimes painful. The reactions were lichenoid, granulomatous, pseudolymphomatous or less specific with a dermal lympho-histiocytic or plasmocytic infiltrate. Other diagnoses included tattoo blow-out (13%), melanoma within a tattoo, naevi within a tattoo (10% each), lichen planus (6%), granulomatous reaction with uveitis, sarcoidosis and dermatofibroma (3% each). Allergic tattoo reactions were mainly treated with local corticosteroid (CS) ointments, CS infiltration or surgical removal. This review is the largest series of tattoo complications in the Baltic area. It illustrates the wide spectrum of complications. Prospective, controlled therapeutic studies are necessary to assess the best treatment protocols for tattoo allergies and tattoo reaction management in general. © 2017 S. Karger AG, Basel.

  12. 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)

  13. PRE-FLARE CORONAL JET AND EVOLUTIONARY PHASES OF A SOLAR ERUPTIVE PROMINENCE ASSOCIATED WITH THE M1.8 FLARE: SDO AND RHESSI OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Bhuwan; Kushwaha, Upendra [Udaipur Solar Observatory, Physical Research Laboratory, Udaipur 313001 (India); Veronig, Astrid M. [Kanzelhöhe Observatory/Institute of Physics, University of Graz, Universitätsplatz 5, A-8010 Graz (Austria); Cho, K.-S., E-mail: bhuwan@prl.res.in [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of)

    2016-12-01

    We investigate the triggering, activation, and ejection of a solar eruptive prominence that occurred in a multi-polar flux system of active region NOAA 11548 on 2012 August 18 by analyzing data from the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory , the Reuven Ramaty High Energy Solar Spectroscopic Imager , and the Extreme Ultraviolet Imager/Sun Earth Connection Coronal and Heliospheric Investigation on board the Solar Terrestrial Relation Observatory . Prior to the prominence activation, we observed striking coronal activities in the form of a blowout jet, which is associated with the rapid eruption of a cool flux rope. Furthermore, the jet-associated flux rope eruption underwent splitting and rotation during its outward expansion. These coronal activities are followed by the prominence activation during which it slowly rises with a speed of ∼12 km s{sup −1} while the region below the prominence emits gradually varying EUV and thermal X-ray emissions. From these observations, we propose that the prominence eruption is a complex, multi-step phenomenon in which a combination of internal (tether-cutting reconnection) and external (i.e., pre-eruption coronal activities) processes are involved. The prominence underwent catastrophic loss of equilibrium with the onset of the impulsive phase of an M1.8 flare, suggesting large-scale energy release by coronal magnetic reconnection. We obtained signatures of particle acceleration in the form of power-law spectra with hard electron spectral index ( δ  ∼ 3) and strong HXR footpoint sources. During the impulsive phase, a hot EUV plasmoid was observed below the apex of the erupting prominence that ejected in the direction of the prominence with a speed of ∼177 km s{sup −1}. The temporal, spatial, and kinematic correlations between the erupting prominence and the plasmoid imply that the magnetic reconnection supported the fast ejection of prominence in the lower corona.

  14. Experiments on hydraulically-compensated Compressed Air Energy Storage (CAES) system using large-diameter vertical pipe two-phase flow test facility: test facility and test procedure

    International Nuclear Information System (INIS)

    Ohtsu, Iwao; Murata, Hideo; Kukita, Yutaka; Kumamaru, Hiroshige.

    1996-07-01

    JAERI, the University of Tokyo, the Central Research Institute of Electric Power Industry and Shimizu Corporation jointing performed and experimental study on two-phase flow in the hydraulically-compensated Compressed Air Energy Storage (CAES) system with a large-diameter vertical pipe two-phase flow test facility from 1993 to 1995. A hydraulically-compensated CAES system is a proposed, conceptual energy storage system where energy is stored in the form of compressed air in an underground cavern which is sealed by a deep (several hundred meters) water shaft. The shaft water head maintains a constant pressure in the cavern, of several mega Pascals, even during loading or unloading of the cavern with air. The dissolved air in the water, however, may create voids in the shaft when the water rises through the shaft during the loading, being forced by the air flow into the cavern. The voids may reduce the effective head of the shaft, and thus the seal may fail, if significant bubbling should occur in the shaft. This bubbling phenomenon (termed 'Champaign effect') and potential failure of the water seal ('blowout') are simulated in a scaled-height, scaled-diameter facility. Carbon dioxide is used to simulate high solubility of air in the full-height, full-pressure system. This report describes the expected and potential two-phase flow phenomena in a hydraulically-compensated CAES system, the test facility and the test procedure, a method to estimate quantities which are not directly measured by using measured quantities and hydrodynamic basic equations, and desirable additional instrumentation. (author)

  15. The Halloween Lateral Canthotomy Model

    Directory of Open Access Journals (Sweden)

    Nur-Ain Nadir

    2017-04-01

    Full Text Available Audience: The Halloween Lateral Canthotomy Model” is designed to instruct Emergency Medicine residents PGY 1-4, as well as Emergency Medicine-bound students. Introduction: Although uncommon, retrobulbar hemorrhage associated with facial trauma is a potential cause of permanent vision loss due to orbital compartment syndrome. To prevent vision loss, treatment with lateral canthotomy is time-sensitive and to perform this procedure in an emergent setting requires properly trained practitioners. Objectives: The purpose of the model is to teach residents and students how to perform lateral canthotomy and to achieve competency in their skills. Method: Lateral canthotomy is an important skill to be proficient in for any Emergency Medicine Physician, as it is an uncommon, sight-saving procedure. It is indicated in scenarios of facial trauma that cause a retrobulbar hemorrhage. Patients are at risk for permanent vision loss due to acute orbital compartment syndrome if the procedure is not done expeditiously.1 A less likely cause of retrobulbar hemorrhage is spontaneous hemorrhage due to a bleeding disorder or anticoagulant use.2 The features of retrobulbar hemorrhage include acute loss of visual acuity, relative afferent pupillary defect, proptosis with resistance to retropulsion, increased intraocular pressure, and limited extra ocular movement.3 While the diagnosis is clinical, it can be confirmed by computed tomography (CT and measurement of intraocular pressure.2 When the diagnosis is established, lateral canthotomy and cantholysis should be performed emergently. Cantholysis is contraindicated when a globe rupture is suspected or with an orbital blowout fracture. Potential complications of this procedure include iatrogenic injury to the globe or lateral rectus muscle, damage to the elevator aponeurosis resulting in ptosis, injury to the lacrimal gland and lacrimal artery, bleeding and infection.3 This task trainer uses affordable materials to let

  16. 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.

  17. Is Exposure to Macondo Oil Reflected in the Otolith Chemistry of Marsh-Resident Fish?

    Science.gov (United States)

    López-Duarte, Paola C; Fodrie, F Joel; Jensen, Olaf P; Whitehead, Andrew; Galvez, Fernando; Dubansky, Benjamin; Able, Kenneth W

    2016-01-01

    Genomic and physiological responses in Gulf killifish (Fundulus grandis) in the northern Gulf of Mexico have confirmed oil exposure of resident marsh fish following the Macondo blowout in 2010. Using these same fish, we evaluated otolith microchemistry as a method for assessing oil exposure history. Laser-ablation inductively-coupled-plasma mass spectrometry was used to analyze the chemical composition of sagittal otoliths to assess whether a trace metal signature could be detected in the otoliths of F. grandis collected from a Macondo-oil impacted site in 2010, post-spill relative to pre-spill, as well as versus fish from areas not impacted by the spill. We found no evidence of increased concentrations of two elements associated with oil contamination (nickel and vanadium) in F. grandis otoliths regardless of Macondo oil exposure history. One potential explanation for this is that Macondo oil is relatively depleted of those metals compared to other crude oils globally. During and after the spill, however, elevated levels of barium, lead, and to a lesser degree, copper were detected in killifish otoliths at the oil-impacted collection site in coastal Louisiana. This may reflect oil contact or other environmental perturbations that occurred concomitant with oiling. For example, increases in barium in otoliths from oil-exposed fish followed (temporally) freshwater diversions in Louisiana in 2010. This implicates (but does not conclusively demonstrate) freshwater diversions from the Mississippi River (with previously recorded higher concentrations of lead and copper), designed to halt the ingress of oil, as a mechanism for elevated elemental uptake in otoliths of Louisiana marsh fishes. These results highlight the potentially complex and indirect effects of the Macondo oil spill and human responses to it on Gulf of Mexico ecosystems, and emphasize the need to consider the multiple stressors acting simultaneously on inshore fish communities.

  18. Clinical use of AO three-dimensionally preformed titanium mesh plates for orbital fractures

    Directory of Open Access Journals (Sweden)

    Ming Chen

    2015-01-01

    Full Text Available AIM:To evaluate the accuracy and practicability of three-dimensionally preformed Arbeitsgemeinschaft Osteosynthese AO titanium mesh plates for orbital fractures.METHODS:Forty-seven patients with isolated blow-out orbital fractures were included in this study. Fracture locations were as follows: floor/medial wall(n=26, 55%, medial wall(n=12, 26%, and floor(n=9, 19%. The floor fractures were exposed by a standard transconjunctival approach, whereas a combined transcaruncular transconjunctival approach was used in patients with medial wall fractures with temporary dissection of inferior oblique muscle. A three-dimensionally preformed AO titanium mesh plate was selected according to the size of the defect previously measured on the preoperative computed tomographic scan examination and fixed at the inferior orbital rim with 2 screws. The accuracy of plate positioning of the reconstructed orbit was assessed on the postoperative computed tomography(CTscan. The practicability of clinical use of AO three-dimensionally preformed titanium mesh plates was assessed on the preoperative and postoperative clinical data.RESULTS: Postoperative orbital CT scan showed an anatomic three-dimensional placement of the orbital mesh plates in all of the patients. All patients had a successful treatment outcome without clinical complications. 40 patients(87%had a successful enophthalmos correction. 25 patients(86%had a successful recovery from diplopia.CONCLUSION: Three-dimensionally preformed AO titanium mesh plates for orbital fracture reconstruction results in an accurate anatomic restoration of the bony orbital contour with a high rate of success to correctenophthalmos and diplopia.

  19. Sand incursion into temperate (Lithuania) and tropical (the Bahamas) maritime vegetation: Georadar visualization of target-rich aeolian lithosomes

    Science.gov (United States)

    Buynevich, Ilya V.; Savarese, Michael; Curran, H. Allen; Bitinas, Albertas; Glumac, Bosiljka; Pupienis, Donatas; Kopcznski, Karen; Dobrotin, Nikita; Gnivecki, Perry; Boush, Lisa Park; Damušytė, Aldona

    2017-08-01

    Interaction of windblown sand with maritime vegetation, either as dune migration or episodic grain transport is a common phenomenon along many sandy coasts. Vegetation introduces antecedent surface roughness, especially when scaled to the landform height, but its role may be concealed if overwhelmed by aeolian incursion and burial. Where field observations and cores lack detail for characterizing this complex process, ground-penetrating radar (GPR) offers continuous visualization of aeolian sequences. Along the Curonian Spit, Lithuania, dune reactivation phases resulted in massive invasion of siliciclastic sand triggered by natural perturbations and land clearance. Massive (>30 m high) dunes entombed mature pine, oak, and alder stands and this process is ongoing. Mid-frequency (200 MHz) georadar surveys reveal landward-dipping lateral accretion surfaces interrupted by high-amplitude point-source anomalies produced by recently buried trees. In tropical regions, dense vegetation and potential for rapid lithification of carbonate sand results in more complex internal structures. Along the windward coast of San Salvador Island, the Bahamas, a massive dune has buried several generations of maritime scrubland, resulting in highly chaotic reflection pattern and high target density. On a nearby Little Exuma Island, numerous reentrants in aeolianites promoted formation of blowouts and incursion of windblown sand 10-25 m into a silver thatch palm forest. High-frequency (800 MHz) GPR images resolve diffractions from trunks and roots buried by > 2 m of oolitic sand. Basal refection morphology helps differentiate the irregular dune/beachrock surface from a smooth palm-frond mat. Aside from detecting and mapping buried vegetation, geophysical images capture its effect on sediment accumulation. This has the potential for differentiating its effect from other discordant structures within dunes (clasts, dissolution voids, trunk molds, burrows, and cultural remains).

  20. 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.

  1. Plasma Jets and Eruptions in Solar Coronal Holes: A Three-dimensional Flux Emergence Experiment

    Science.gov (United States)

    Moreno-Insertis, F.; Galsgaard, K.

    2013-07-01

    A three-dimensional (3D) numerical experiment of the launching of a hot and fast coronal jet followed by several violent eruptions is analyzed in detail. These events are initiated through the emergence of a magnetic flux rope from the solar interior into a coronal hole. We explore the evolution of the emerging magnetically dominated plasma dome surmounted by a current sheet and the ensuing pattern of reconnection. A hot and fast coronal jet with inverted-Y shape is produced that shows properties comparable to those frequently observed with EUV and X-ray detectors. We analyze its 3D shape, its inhomogeneous internal structure, and its rise and decay phases, lasting for some 15-20 minutes each. Particular attention is devoted to the field line connectivities and the reconnection pattern. We also study the cool and high-density volume that appears to encircle the emerged dome. The decay of the jet is followed by a violent phase with a total of five eruptions. The first of them seems to follow the general pattern of tether-cutting reconnection in a sheared arcade, although modified by the field topology created by the preceding reconnection evolution. The two following eruptions take place near and above the strong-field concentrations at the surface. They show a twisted, Ω-loop-like rope expanding in height, with twist being turned into writhe, thus hinting at a kink instability (perhaps combined with a torus instability) as the cause of the eruption. The succession of a main jet ejection and a number of violent eruptions that resemble mini-CMEs and their physical properties suggest that this experiment may provide a model for the blowout jets recently proposed in the literature.

  2. 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

  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)

    Djizanne-Djakeun, Hippolyte

    2014-01-01

    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. Numerical model for surge and swab pressures on wells with cross-section variation

    Energy Technology Data Exchange (ETDEWEB)

    Fedevjcyk, Joao Victor; Junqueira, Silvio Luiz de Mello; Negrao, Cezar Otaviano Ribeiro [UTFPR - Federal University of Technology - Parana - Curitiba, PR (Brazil)], e-mails: silvio@utfpr.edu.br, negrao@utfpr.edu.br

    2010-07-01

    Drilling is one of the most complex steps in petroleum exploration. The process is accomplished by rotating a drill bit to compress the rock formation. During drilling, a fluid is pumped into the well to lubricate and cool down the drill bit, to clean up the well, to avoid the formation fluid influx to the well and also to stabilize the borehole walls. Fluid circulation, however, can be interrupted for maintenance reasons and the drill pipe can be moved to remove the drill bit. The downward or upward movement of the drill pipe displaces the fluid within the well causing either under pressure (swab) or over pressure (surge), respectively. If the pressure at the well bore overcomes the formation fracture pressure, a loss of circulation can take place. On the other way round, the upward movement may reduce the pressure below the pore pressure and an inflow of fluid to the well (kick) can occur. An uncontrolled kick may cause a blowout with serious damages. The transient flow induced by the axial movement of the drill pipe is responsible for the pressure changes at the well bore. Nevertheless, the well bore cross section variation may modify the pressure change within the pipe. In this paper, the effects of diameter variation of the drilling well on the surge and swab pressures are investigated. The equations that represent the phenomenon (mass and momentum conservation) are discretized by the finite volume method. Despite its non-Newtonian properties, the fluid is considered Newtonian in this first work. The drill pipe is considered closed and the flow is assumed as single-phased, one-dimensional, isothermal, laminar, compressible and transient. A sensitivity analysis of the flow parameters is carried out. The cross-section changes cause the reflection of the pressure wave, and consequently pressure oscillations. (author)

  5. Methodology for kick tolerance calculation and well killing in deepwater drilling

    Directory of Open Access Journals (Sweden)

    Yequan Jin

    2016-11-01

    Full Text Available Kick tolerance is a key parameter to indicate whether shut-in operation can be carried out safely and a proper well killing method should be chosen in well drilling. At present, however, the calculation of kick tolerance in deepwater drilling is not efficient enough. In this paper, a calculation method for volume kick tolerance of deepwater drilling was developed by means of theoretical derivation and example verification. Based on deepwater borehole temperature profile, choke manifold and annulus circulating pressure loss, the calculation model of volume kick tolerance was established under the constraint of the pressure-bearing capacity of the formation at the casing shoe, resistance to internal pressure of casing, blowout preventer (BOP and choke control. Then, its reliability was verified by using the calculation results of a deepwater well in the South China Sea. It is indicated that the well can be shut in safely and the well killing will be safer if the Engineer's Method is used. The result is in agreement with the measures that were adopted on site. Finally, the newly developed calculation model was compared with those which don't take temperature and pressure loss into account, and the effect of choke manifold, annulus pressure loss and temperature inside wellbore on kick tolerance was analyzed. It is shown that the volume kick tolerance will get smaller if the effect of pressure loss and temperature is not taken into account, and the well killing conditions will be more rigorous. In addition, the technical measures to increase kick tolerance were proposed after the influential laws of pit gain and overflow depth on kick tolerance were analyzed.

  6. 40-year analysis of US oil spillage rates

    Energy Technology Data Exchange (ETDEWEB)

    Etkin, D.S. [Environmental Research Consulting, Cortlandt Manor, NY (United States)

    2009-07-01

    Environmentalists are concerned about the plans to open US offshore and Arctic regions for oil exploration and production. The US environmental movement gained ground after the Santa Barbara well blowout in 1969. Following the Exxon Valdez spill in 1989, the movement spurred regulatory changes and industry initiatives to prevent oil spills. The implementation of prevention-oriented regulations and voluntary industry initiatives have contributed to a considerable reduction in spillage over the past 40 years. This presentation provided average annual total petroleum industry and non-industry spillage statistics during that time frame. In this study, oil was referred to as a broadly-defined class of liquid hydrocarbon mixtures, including crude oil and liquid refined petroleum products and waste oils, but did not include BTEX compounds, petroleum chemicals or highly-volatile liquids. Spills were defined as an event in which oil is accidentally, or occasionally intentionally, released to the environment. The presentation addressed issues regarding natural seeps and spillage from oil industry activities. This included spills associated with offshore oil exploration and production activities; spills from inland production wells; spills from oil tank vessels and non-tank vessels; spills from coastal and inland pipes; spills from railroads, tanker trucks and oil refining; spills related to oil consumption; spills from coastal marine facilities; spills from gas stations and truck stops; spills from residential home heating oil tanks; and spills from motor vehicles. Legally permitted oil discharges were discussed with reference to produced water, refinery effluent discharges, and lubricants from vessels. The study showed that over the last decade, the largest source category of spillage was inland pipelines followed by EPA-regulated facilities. Changes in spillage rates between 1988 and 1997 has shown that there has been a general downward trend in US spills. 18 refs., 33

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

    International Nuclear Information System (INIS)

    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

  8. A COMPREHENSIVE DUST MODEL APPLIED TO THE RESOLVED BETA PICTORIS DEBRIS DISK FROM OPTICAL TO RADIO WAVELENGTHS

    Energy Technology Data Exchange (ETDEWEB)

    Ballering, Nicholas P.; Su, Kate Y. L.; Rieke, George H.; Gáspár, András, E-mail: ballerin@email.arizona.edu [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)

    2016-06-01

    We investigate whether varying the dust composition (described by the optical constants) can solve a persistent problem in debris disk modeling—the inability to fit the thermal emission without overpredicting the scattered light. We model five images of the β Pictoris disk: two in scattered light from the Hubble Space Telescope ( HST )/Space Telescope Imaging Spectrograph at 0.58 μ m and HST /Wide Field Camera 3 (WFC 3) at 1.16 μ m, and three in thermal emission from Spitzer /Multiband Imaging Photometer for Spitzer (MIPS) at 24 μ m, Herschel /PACS at 70 μ m, and Atacama Large Millimeter/submillimeter Array at 870 μ m. The WFC3 and MIPS data are published here for the first time. We focus our modeling on the outer part of this disk, consisting of a parent body ring and a halo of small grains. First, we confirm that a model using astronomical silicates cannot simultaneously fit the thermal and scattered light data. Next, we use a simple generic function for the optical constants to show that varying the dust composition can improve the fit substantially. Finally, we model the dust as a mixture of the most plausible debris constituents: astronomical silicates, water ice, organic refractory material, and vacuum. We achieve a good fit to all data sets with grains composed predominantly of silicates and organics, while ice and vacuum are, at most, present in small amounts. This composition is similar to one derived from previous work on the HR 4796A disk. Our model also fits the thermal spectral energy distribution, scattered light colors, and high-resolution mid-IR data from T-ReCS for this disk. Additionally, we show that sub-blowout grains are a necessary component of the halo.

  9. HERSCHEL OBSERVATIONS AND UPDATED SPECTRAL ENERGY DISTRIBUTIONS OF FIVE SUNLIKE STARS WITH DEBRIS DISKS

    Energy Technology Data Exchange (ETDEWEB)

    Dodson-Robinson, Sarah E. [Department of Physics and Astronomy, University of Delaware, 217 Sharp Lab, Newark, DE 19716 (United States); Su, Kate Y. L. [Steward Observatory, Department of Astronomy, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Bryden, Geoff [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Harvey, Paul; Green, Joel D., E-mail: sdr@udel.edu [Astronomy Department, University of Texas, 2515 Speedway Drive C1400, Austin, TX 78712 (United States)

    2016-12-20

    Observations from the Herschel Space Observatory have more than doubled the number of wide debris disks orbiting Sunlike stars to include over 30 systems with R  > 100 AU. Here, we present new Herschel PACS and reanalyzed Spitzer MIPS photometry of five Sunlike stars with wide debris disks, from Kuiper Belt size to R  > 150 AU. The disk surrounding HD 105211 is well resolved, with an angular extent of >14″ along the major axis, and the disks of HD 33636, HD 50554, and HD 52265 are extended beyond the PACS point-spread function size (50% of energy enclosed within radius 4.″23). HD 105211 also has a 24 μ m infrared excess, which was previously overlooked, because of a poorly constrained photospheric model. Archival Spitzer IRS observations indicate that the disks have small grains of minimum radius a {sub min} ∼ 3 μ m, although a {sub min} is larger than the radiation-pressure blowout size in all systems. If modeled as single-temperature blackbodies, the disk temperatures would all be <60 K. Our radiative transfer models predict actual disk radii approximately twice the radius of a model blackbody disk. We find that the Herschel photometry traces dust near the source population of planetesimals. The disk luminosities are in the range 2 × 10{sup −5} ⩽  L / L {sub ⊙} ⩽ 2 × 10{sup −4}, consistent with collisions in icy planetesimal belts stirred by Pluto-size dwarf planets.

  10. Numerical simulation of terrain-induced severe slugging coupled by hydrodynamic slugs in a pipeline–riser system

    International Nuclear Information System (INIS)

    Han, Pengfei; Guo, Liejin

    2015-01-01

    Highlights: • A hyperbolized two-fluid model is presented for a pipeline–riser system. • The coupling of severe slugging and hydrodynamic slugging is realized. • Accurate predictions are obtained with consideration of the coupling effect. • The effect of hydrodynamic slugs on severe slugging is addressed. - Abstract: A numerical study based on a one-dimensional two-fluid model is carried out to describe the transient hydrodynamic slugging and terrain-induced severe slugging in a pipeline–riser system. The system of equations is rendered well-posed by interfacial pressure model for the riser. The selected flow conditions are restricted in the well-posed region for the horizontal and the downward inclined pipes to ensure the hydrodynamic slug characteristics are predicted correctly. The validity of the model is examined by water faucet problem and horizontal slug flow experiments. Simulations with and without slug capturing are conducted to address the effect of hydrodynamic slugs on severe slugging. It has been found that more accurate predictions are obtained by taking hydrodynamic slugs into account. At low superficial gas velocity, the simulation without slug capturing tends to overestimate the severe slugging period. When hydrodynamic slugs are captured, the upstream gas expansion is suppressed by the hydrodynamic slugs. At relatively high superficial gas velocity, the simulation without slug capturing tends to underestimate the severe slugging period. When hydrodynamic slugs are captured, the upstream compressible volume is greatly enlarged by the blowout of the hydrodynamic slugs. In both situations, the influences of the hydrodynamic slugs can reduce the errors of the predicted severe slugging characteristics.

  11. Field observations of artificial sand and oil agglomerates

    Science.gov (United States)

    Dalyander, Patricia (Soupy); Long, Joseph W.; Plant, Nathaniel G.; McLaughlin, Molly R.; Mickey, Rangley C.

    2015-01-01

    Oil that comes into the surf zone following spills, such as occurred during the 2010 Deepwater Horizon (DWH) blowout, can mix with local sediment to form heavier-than-water sand and oil agglomerates (SOAs), at times in the form of mats a few centimeters thick and tens of meters long. Smaller agglomerates that form in situ or pieces that break off of larger mats, sometimes referred to as surface residual balls (SRBs), range in size from sand-sized grains to patty-shaped pieces several centimeters (cm) in diameter. These mobile SOAs can cause beach oiling for extended periods following the spill, on the scale of years as in the case of DWH. Limited research, including a prior effort by the U.S. Geological Survey (USGS) investigating SOA mobility, alongshore transport, and seafloor interaction using numerical model output, focused on the physical dynamics of SOAs. To address this data gap, we constructed artificial sand and oil agglomerates (aSOAs) with sand and paraffin wax to mimic the size and density of genuine SOAs. These aSOAs were deployed in the nearshore off the coast of St. Petersburg, Florida, during a field experiment to investigate their movement and seafloor interaction. This report presents the methodology for constructing aSOAs and describes the field experiment. Data acquired during the field campaign, including videos and images of aSOA movement in the nearshore (1.5-meter and 0.5-meter water depth) and in the swash zone, are also presented in this report.

  12. Transportal anterior cruciate ligament reconstruction with quadrupled hamstring tendon graft: A prospective outcome study

    Directory of Open Access Journals (Sweden)

    Chandan Kumar

    2017-01-01

    Full Text Available Background: Anterior cruciate ligament (ACL reconstruction has been one of the most commonly performed procedures throughout the world. Unsatisfactory outcome with conventional ACL reconstruction has been attributed to nonanatomic graft placement. Researchers have advised placing the graft in the native footprint of ACL to avoid nonanatomic graft placement. The goal of this study was to analyze the outcome of anatomic single bundle ACL reconstruction using transportal technique. Materials and Methods: This was a prospective outcome study conducted on 85 consecutive patients of ACL reconstruction of which 62 patients met inclusion and exclusion criteria and were analyzed for final results. All the patients underwent ACL reconstruction by quadrupled hamstring tendon graft using transportal technique and the accessory anteromedial (AAM portal for femoral tunnel creation. The graft was fixed with endobutton on femoral side and bioabsorbable screw on the tibial side. Patients were evaluated for range of motion, International Knee Documentation Committee (IKDC score, and Lysholm scores at a minimum followup period of 2 years. The mean pre- and postoperative scores were compared using Wilcoxon signed-rank test. Results: The mean Lysholm and IKDC scores improved significantly (P < 0.0001 from preoperative value. According to IKDC score, 90.3% (n = 56 were either normal or near normal at final followup. According to Lysholm score, 75.8% of patients had excellent and 13.3% had good results. Preoperatively, pivot shift was present in 85.5% (n = 53 of patients which reduced to 4.8% (n = 3 postoperatively. Infection and knee stiffness occurred in two patients, and femoral tunnel blowout and graft re-rupture occurred in one patient each. Conclusion: Anatomic ACL reconstruction by AAM portal is a reproducible technique which gives good clinical outcome at short-term followup.

  13. A disrupted molecular torus around Eta Carinae as seen in 12CO with ALMA

    Science.gov (United States)

    Smith, Nathan; Ginsburg, Adam; Bally, John

    2018-03-01

    We present Atacama Large Millimeter Array (ALMA) observations of 12CO 2-1 emission from circumstellar material around the massive star Eta Carinae (η Car). These observations reveal new structural details about the cool equatorial torus located ˜4000 au from the star. The CO torus is not a complete azimuthal loop, but rather, is missing its near side, which appears to have been cleared away. The missing material matches the direction of apastron in the eccentric binary system, making it likely that η Car's companion played an important role in disrupting portions of the torus soon after ejection. Molecular gas seen in ALMA data aligns well with the cool dust around η Car previously observed in mid-infrared (IR) maps, whereas hot dust resides at the inner surface of the molecular torus. The CO also coincides with the spatial and velocity structure of near-IR H2 emission. Together, these suggest that the CO torus seen by ALMA is actually the pinched waist of the Homunculus polar lobes, which glows brightly because it is close to the star and warmer than the poles. The near side of the torus appears to be a blowout, associated with fragmented equatorial ejecta. We discuss implications for the origin of various features north-west of the star. CO emission from the main torus implies a total gas mass in the range of 0.2-1 M⊙ (possibly up to 5 M⊙ or more, although with questionable assumptions). Deeper observations are needed to constrain CO emission from the cool polar lobes.

  14. High Resolution DNS of Turbulent Flows using an Adaptive, Finite Volume Method

    Science.gov (United States)

    Trebotich, David

    2014-11-01

    We present a new computational capability for high resolution simulation of incompressible viscous flows. Our approach is based on cut cell methods where an irregular geometry such as a bluff body is intersected with a rectangular Cartesian grid resulting in cut cells near the boundary. In the cut cells we use a conservative discretization based on a discrete form of the divergence theorem to approximate fluxes for elliptic and hyperbolic terms in the Navier-Stokes equations. Away from the boundary the method reduces to a finite difference method. The algorithm is implemented in the Chombo software framework which supports adaptive mesh refinement and massively parallel computations. The code is scalable to 200,000 + processor cores on DOE supercomputers, resulting in DNS studies at unprecedented scale and resolution. For flow past a cylinder in transition (Re = 300) we observe a number of secondary structures in the far wake in 2D where the wake is over 120 cylinder diameters in length. These are compared with the more regularized wake structures in 3D at the same scale. For flow past a sphere (Re = 600) we resolve an arrowhead structure in the velocity in the near wake. The effectiveness of AMR is further highlighted in a simulation of turbulent flow (Re = 6000) in the contraction of an oil well blowout preventer. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Advanced Scientific Computing Research, Applied Mathematics program under Contract Number DE-AC02-05-CH11231.

  15. Thermoresponsive Microcarriers for Smart Release of Hydrate Inhibitors under Shear Flow.

    Science.gov (United States)

    Lee, Sang Seok; Park, Juwoon; Seo, Yutaek; Kim, Shin-Hyun

    2017-05-24

    The hydrate formation in subsea pipelines can cause oil and gas well blowout. To avoid disasters, various chemical inhibitors have been developed to prevent or delay the hydrate formation and growth. Nevertheless, direct injection of the inhibitors results in environmental contamination and cross-suppression of inhibition performance in the presence of other inhibitors against corrosion and/or formation of scale, paraffin, and asphaltene. Here, we suggest a new class of microcarriers that encapsulate hydrate inhibitors at high concentration and release them on demand without active external triggering. The key to the success in microcarrier design lies in the temperature dependence of polymer brittleness. The microcarriers are microfluidically created to have an inhibitor-laden water core and polymer shell by employing water-in-oil-in-water (W/O/W) double-emulsion drops as a template. As the polymeric shell becomes more brittle at a lower temperature, there is an optimum range of shell thickness that renders the shell unstable at temperature responsible for hydrate formation under a constant shear flow. We precisely control the shell thickness relative to the radius by microfluidics and figure out the optimum range. The microcarriers with the optimum shell thickness are selectively ruptured by shear flow only at hydrate formation temperature and release the hydrate inhibitors. We prove that the released inhibitors effectively retard the hydrate formation without reduction of their performance. The microcarriers that do not experience the hydration formation temperature retain the inhibitors, which can be easily separated from ruptured ones for recycling by exploiting the density difference. Therefore, the use of microcarriers potentially minimizes the environmental damages.

  16. Spitzer IRS 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.; Sicillia-Aguilar, Aurora; Rieke, George H.; Su, Kate Y. L.

    2011-01-01

    We describe Spitzer IRS spectroscopic observations of the approx. 10 Myr-old star, EF Chao Compositional modeling of the spectra from 5 micron to 35 micron confirms that it is surrounded by a luminous debris disk with L(sub D)/L(sub *) approx. 10(exp -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 pyroxene ratio of approx. 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.

  17. Shifts in the microbial community composition of Gulf Coast beaches following beach oiling.

    Directory of Open Access Journals (Sweden)

    Ryan J Newton

    Full Text Available Microorganisms associated with coastal sands serve as a natural biofilter, providing essential nutrient recycling in nearshore environments and acting to maintain coastal ecosystem health. Anthropogenic stressors often impact these ecosystems, but little is known about whether these disturbances can be identified through microbial community change. The blowout of the Macondo Prospect reservoir on April 20, 2010, which released oil hydrocarbons into the Gulf of Mexico, presented an opportunity to examine whether microbial community composition might provide a sensitive measure of ecosystem disturbance. Samples were collected on four occasions, beginning in mid-June, during initial beach oiling, until mid-November from surface sand and surf zone waters at seven beaches stretching from Bay St. Louis, MS to St. George Island, FL USA. Oil hydrocarbon measurements and NOAA shoreline assessments indicated little to no impact on the two most eastern beaches (controls. Sequence comparisons of bacterial ribosomal RNA gene hypervariable regions isolated from beach sands located to the east and west of Mobile Bay in Alabama demonstrated that regional drivers account for markedly different bacterial communities. Individual beaches had unique community signatures that persisted over time and exhibited spatial relationships, where community similarity decreased as horizontal distance between samples increased from one to hundreds of meters. In contrast, sequence analyses detected larger temporal and less spatial variation among the water samples. Superimposed upon these beach community distance and time relationships, was increased variability in bacterial community composition from oil hydrocarbon contaminated sands. The increased variability was observed among the core, resident, and transient community members, indicating the occurrence of community-wide impacts rather than solely an overprinting of oil hydrocarbon-degrading bacteria onto otherwise

  18. Limiting Short-term Noise versus Optical Density in a Direct Absorption Spectrometer for Trace Gas Detection

    Science.gov (United States)

    Jervis, D.

    2016-12-01

    Field-deployable trace gas monitors are important for understanding a multitude of atmospheric processes: from forest photosynthesis and respiration [1], to fugitive methane emissions [2] and satellite measurement validation [3]. Consequently, a detailed knowledge of the performance limitations of these instruments is essential in order to establish reliable datasets. We present the short-term ( >1 Hz) performance of a long-pass direct absorption spectrometer as a function of the optical density of the absorption transition being probed. In particular, we identify fluctuations in the laser intensity as limiting the optical density uncertainty to 4x10-6/√Hz for weak transitions, and noise in the laser drive current as limiting the fractional noise in the optical density to 4x10-5/√Hz for deep transitions. We provide numerical and analytical predictions for both effects, as well as using the understanding of this phenomena to estimate how noise on neighboring strong and weak transitions couple to each other. All measurements were performed using the Aerodyne Research TILDAS Monitor, but are general to any instrument that uses direct absorption spectroscopy as a detection method. Wehr, R., et al. "Seasonality of temperate forest photosynthesis and daytime respiration." Nature 534.7609 (2016): 680-683. Conley, S., et al. "Methane emissions from the 2015 Aliso Canyon blowout in Los Angeles, CA." Science 351.6279 (2016): 1317-1320. Emmons, L. K., et al. "Validation of Measurements of Pollution in the Troposphere (MOPITT) CO retrievals with aircraft in situ profiles." Journal of Geophysical Research: Atmospheres 109.D3 (2004).

  19. Influence of the Steam Addition on Premixed Methane Air Combustion at Atmospheric Pressure

    Directory of Open Access Journals (Sweden)

    Mao Li

    2017-07-01

    Full Text Available Steam-diluted combustion in gas turbine systems is an effective approach to control pollutant emissions and improve the gas turbine efficiency. The primary purpose of the present research is to analyze the influence of steam dilution on the combustion stability, flame structures, and CO emissions of a swirl-stabilized gas turbine model combustor under atmospheric pressure conditions. The premixed methane/air/steam flame was investigated with three preheating temperatures (384 K/434 K/484 K and the equivalence ratio was varied from stoichiometric conditions to the flammability limits where the flame was physically blown out from the combustor. In order to represent the steam dilution intensity, the steam fraction Ω defined as the steam to air mass flow rate ratio was used in this work. Exhaust gases were sampled with a water-cooled emission probe which was mounted at the combustor exit. A 120 mm length quartz liner was used which enabled the flame visualization and optical measurement. Time-averaged CH chemiluminescence imaging was conducted to characterize the flame location and it was further analyzed with the inverse Abel transform method. Chemical kinetics calculation was conducted to support and analyze the experimental results. It was found that the LBO (lean blowout limits were increased with steam fraction. CH chemiluminescence imaging showed that with a high steam fraction, the flame length was elongated, but the flame structure was not altered. CO emissions were mapped as a function of the steam fraction, inlet air temperature, and equivalence ratios. Stable combustion with low CO emission can be achieved with an appropriate steam fraction operation range.

  20. The dynamical evolution of a young star cluster

    Science.gov (United States)

    Kroupa, P.

    Observations show that the Trapezium Cluster in Orion is at most 1 Myr old, very dense, and containing about six OB stars at its centre. About 50 per cent or more of the cluster stars are binary systems. It may be expanding rapidly due to very recent gas blow-out, or it may be near virial equilibrium, or in cold collapse. The dynamics of the cluster is interesting because (i) it may be too young for dynamical evolution to have established the observed degree of mass segregation, and (ii) the binary population may still be young enough not to have been affected significantly by dynamical evolution. If both are true, then we have evidence that massive stars form at the centres of rich embedded clusters and that the binary proportion varies with star-forming conditions. A number of N-body calculations of model, binary-rich Trapezium Clusters have been performed using Aarseth's Nbody5 programme (Kroupa, Petr & McCaughrean 1998). Here, attention is focused on models in which the star formation efficiency was 50 per cent with instantaneous mass loss. It is found that the model central density and velocity dispersion agree with the observational constraints if expansion is only about 6x10^4 yr old. Additionally, the observed binary proportion constrains the primordial proportion to have been significantly less than in Taurus--Auriga. However, if variation of the birth binary proportion with gas cloud parameters has been detected can only be verified if the cluster can be shown to be expanding rapidly.

  1. 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)

  2. 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.

  3. Toxicity of weathered Deepwater Horizon oil to bay anchovy (Anchoa mitchilli) embryos.

    Science.gov (United States)

    O'Shaughnessy, Kathryn A; Forth, Heather; Takeshita, Ryan; Chesney, Edward J

    2018-02-01

    The BP-contracted Deepwater Horizon Macondo well blowout occurred on 20 April 2010 and lasted nearly three months. The well released millions of barrels of crude oil into the northern Gulf of Mexico, causing extensive impacts on pelagic, benthic, and estuarine fish species. The bay anchovy (Anchoa mitchilli) is an important zooplanktivore in the Gulf, serving as an ecological link between lower trophic levels and pelagic predatory fish species. Bay anchovy spawn from May through November in shallow inshore and estuarine waters throughout the Gulf. Because their buoyant embryos are a dominant part of the inshore ichthyoplankton throughout the summer, it is likely bay anchovy embryos encountered oil in coastal estuaries during the summer and fall of 2010. Bay anchovy embryos were exposed to a range of concentrations of two field-collected Deepwater Horizon oils as high-energy and low-energy water accommodated fractions (HEWAFs and LEWAFs, respectively) for 48h. The median lethal concentrations (LC 50 ) were lower in exposures with the more weathered oil (HEWAF, 1.48µg/L TPAH50; LEWAF, 1.58µg/L TPAH50) compared to the less weathered oil (HEWAF, 3.87µg/L TPAH50; LEWAF, 4.28µg/L TPAH50). To measure delayed mortality and life stage sensitivity between embryos and larvae, an additional 24h acute HEWAF exposure using the more weathered oil was run followed by a 24h grow-out period. Here the LC 50 was 9.71µg/L TPAH50 after the grow-out phase, suggesting a toxic effect of oil at the embryonic or hatching stage. We also found that exposures prepared with the more weathered Slick B oil produced lower LC 50 values compared to the exposures prepared with Slick A oil. Our results demonstrate that even relatively acute environmental exposure times can have a detrimental effect on bay anchovy embryos. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. 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.

  5. Impact of Vitiation on a Swirl-Stabilized and Premixed Methane Flame

    Directory of Open Access Journals (Sweden)

    Mao Li

    2017-10-01

    Full Text Available Vitiation refers to the condition where the oxygen concentration in the air is reduced due to the mix of dilution gas. The vitiation effects on a premixed methane flame were investigated on a swirl-stabilized gas turbine model combustor under atmospheric pressure. The main purpose is to analyze the combustion stability and CO emission performance in vitiated air and compare the results with the flame without vitiation. The N2, CO2, and H2O (steam were used as the dilution gas. Measurements were conducted in a combustor inlet temperature of 384 K and 484 K. The equivalence ratio was varied from stoichiometric conditions to the LBO (Lean Blowout limits where the flame was physically blown out from the combustor. The chemical kinetics calculation was performed with Chemkin software to analyze the vitiation effects on the flame reaction zone. Based on the calculation results, the changes in the temperature gradient, CO concentration, and active radicals across the flame reaction zone were identified. The time-averaged CH chemiluminescence images were recorded and the results indicated the features of the flame shape and location. The CH signal intensity provided the information about the heat-release zone in the combustor. The combustion LBO limits were measured and the vitiation of CO2 and H2O were found to have a stronger impact to elevate the LBO limits than N2. Near the LBO limits, the instability of the flame reaction was revealed by the high-speed chemiluminescence imaging and the results were analyzed by FFT (Fast Fourier Transfer. CO emission was measured with a water-cooled probe which is located at the exit of the combustor. The combustion vitiation has been found to have the compression effect on the operation range for low CO emission. However, this compression effect could be compensated by improving the combustor inlet temperature.

  6. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Gilkey, Amy P. (GRAM Inc., Albuquerque, NM); Hansen, Clifford W.; Schatz, John F. (John F. Schatz Research & Consulting, Inc., Del Mar, CA); Rudeen, David Keith (GRAM Inc., Albuquerque, NM); Lord, David L.

    2006-02-01

    This report presents a model to estimate the spallings releases for the Waste Isolation Pilot Plant Performance Assessment (WIPP PA). A spallings release in the context of WIPP PA refers to a portion of the solid waste transported from the subsurface repository to the ground surface due to inadvertent oil or gas drilling into the WIPP repository at some time after site closure. Some solid waste will be removed by the action of the drillbit and drilling fluid; this waste is referred to as cuttings and cavings. If the repository is pressurized above hydrostatic at the time of intrusion, solid waste material local to the borehole may be subject to mechanical failure and entrainment in high-velocity gases as the repository pressure is released to the borehole. Solid material that fails and is transported into the wellbore and thus to the surface comprise the spallings releases. The spallings mechanism is analogous to a well blowout in the modern oil and gas drilling industry. The current spallings conceptual model and associated computer code, DRSPALL, were developed for the 2004 recertification because the prior spallings model used in the 1996 WIPP Compliance Certification Application (CCA) was judged by an independent peer review panel as inadequate (DOE 1996, 9.3.1). The current conceptual model for spallings addresses processes that take place several minutes before and after a borehole intrusion of a WIPP waste room. The model couples a pipe-flow wellbore model with a porous flow repository model, allowing high-pressure gas to flow from the repository to the wellbore through a growing cavity region at the well bottom. An elastic stress model is applied to the porous solid domain that allows for mechanical failure of repository solids if local tensile stress exceeds the tensile strength of the waste. Tensile-failed solids may be entrained into the wellbore flow stream by a fluidized bed model, in which case they are ultimately transported to the land surface

  8. The impact of fire on sand dune stability: Surface coverage and biomass recovery after fires on Western Australian coastal dune systems from 1988 to 2016

    Science.gov (United States)

    Shumack, Samuel; Hesse, Paul; Turner, Liam

    2017-12-01

    seedbank or resprouting density. Image classification did not identify any new blowout features except where fires were not the primary cause. Results suggest that fires are not presently contributing to the destabilisation of coastal dunes in south-west WA.

  9. Coupled LBM-DEM Three-phase Simulation on Gas Flux Seeping from Marine Sediment

    Science.gov (United States)

    Kano, Y.; Sato, T.

    2014-12-01

    One of the main issues of the geological storage of CO2 under the seabed is a risk of CO2 leakage. Once CO2seeps into the ocean, it rises in water column dissolving into seawater, which results in the acidification of seawater and/or returning to the air. Its behaviour significantly depends on flow rate and bubble size (Kano et al., 2009; Dewar et al., 2013). As for porous media, bubble size is generally predicted through simple force balance based on flow rate, surface tension and channel size which is estimated by porosity and grain size. However, in shallow marine sediments, grains could be mobilised and displaced by buoyant gas flow, which causes distinctive phenomena such as blow-out or formation of gas flow conduit. As a result, effective gas flux into seawater can be intermissive, and/or concentrated in narrow area (QICS, 2012; Kawada, 2013). Bubble size is also affected by these phenomena. To predict effective gas flux and bubble size into seawater, three-phase behaviour of gas-water-sediment grains should be revealed. In this presentation, we will report the results of gas-liquid-solid three-phase simulations and their comparisons with experimental and observation data. Size of solid particles is based on grain size composing marine sediments at some CCS project sites. Fluid-particle interactions are solved using the lattice Boltzmann method (LBM), while the particle-particle interactions are treated by coupling with the Discrete Element method (DEM). References: Dewar, M., Wei, W., McNeil, D., Chen, B., 2013. Small-scale modelling of the physiochemical impacts of CO2leaked from sub-seabed reservoirs or pipelines within the North Sea and surrounding waters. Marine Pollution Bulletin 73(2), 504-515. Kano, Y., Sato, T., Kita, J., Hirabayashi, S., Tabeta, S., 2009. Model prediction on the rise of pCO2 in uniform flows by leakage of CO2purposefully stored under the seabed. Int. J. Greenhouse Gas Control, Vol. 3(5), 617-625. Kawada, R. 2014. A study on the

  10. Salvage Reirradiaton With Stereotactic Body Radiotherapy for Locally Recurrent Head-and-Neck Tumors

    International Nuclear Information System (INIS)

    Cengiz, Mustafa; Ozyigit, Goekhan; Yazici, Goezde; Dogan, Ali; Yildiz, Ferah; Zorlu, Faruk; Guerkaynak, Murat; Gullu, Ibrahim H.; Hosal, Sefik; Akyol, Fadil

    2011-01-01

    Purpose: In this study, we present our results of reirradiation of locally recurrent head-and-neck cancer with image-guided, fractionated, frameless stereotactic body radiotherapy technique. Methods and Materials: From July 2007 to February 2009, 46 patients were treated using the CyberKnife (Accuray, Sunnyvale, CA) at the Department of Radiation Oncology, Hacettepe University, Ankara, Turkey. All patients had recurrent, unresectable, and previously irradiated head-and-neck cancer. The most prominent site was the nasopharynx (32.6%), and the most common histopathology was epidermoid carcinoma. The planning target volume was defined as the gross tumor volume identified on magnetic resonance imaging and computed tomography. There were 22 female and 24 male patients. Median age was 53 years (range, 19-87 years). The median tumor dose with stereotactic body radiotherapy was 30 Gy (range, 18-35 Gy) in a median of five (range, one to five) fractions. Results: Of 37 patients whose response to therapy was evaluated, 10 patients (27%) had complete tumor regression, 11 (29.8%) had partial response, and 10 (27%) had stable disease. Ultimate local disease control was achieved in 31 patients (83.8%). The overall survival was 11.93 months in median (ranged, 11.4 - 17.4 months), and the median progression free survival was 10.5 months. One-year progression-free survival and overall survival were 41% and 46%, respectively. Grade II or greater long-term complications were observed in 6 (13.3%) patients. On follow-up, 8 (17.3%) patients had carotid blow-out syndrome, and 7 (15.2%) patients died of bleeding from carotid arteries. We discovered that this fatal syndrome occurred only in patients with tumor surrounding carotid arteries and carotid arteries receiving all prescribed dose. Conclusions: Stereotactic body radiotherapy is an appealing treatment option for patients with recurrent head-and-neck cancer previously treated with radiation to high doses. Good local control with

  11. HERSCHEL's ''COLD DEBRIS DISKS'': BACKGROUND GALAXIES OR QUIESCENT RIMS OF PLANETARY SYSTEMS?

    Energy Technology Data Exchange (ETDEWEB)

    Krivov, A. V.; Loehne, T.; Mutschke, H.; Neuhaeuser, R. [Astrophysikalisches Institut und Universitaetssternwarte, Friedrich-Schiller-Universitaet Jena, Schillergaesschen 2-3, D-07745 Jena (Germany); Eiroa, C.; Marshall, J. P.; Mustill, A. J. [Departamento de Fisica Teorica, Facultad de Ciencias, Universidad Autonoma de Madrid, Cantoblanco, E-28049 Madrid (Spain); Montesinos, B. [Departamento de Astrofisica, Centro de Astrobiologia (CAB, CSIC-INTA), ESAC Campus, P.O. Box 78, E-28691 Villanueva de la Canada, Madrid (Spain); Del Burgo, C. [Instituto Nacional de Astrofisica, Optica y Electronica (INAOE), Apartado Postal 51 y 216, 72000 Puebla, Pue. (Mexico); Absil, O. [Institut d' Astrophysique et de Geophysique, Universite de Liege, Allee du 6 Aout 17, B-4000 Liege (Belgium); Ardila, D. [NASA Herschel Science Center, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Augereau, J.-C.; Ertel, S.; Lebreton, J. [UJF-Grenoble 1/CNRS-INSU, Institut de Planetologie et d' Astrophysique de Grenoble (IPAG), UMR 5274, F-38041 Grenoble (France); Bayo, A. [European Southern Observatory, Alonso de Cordova 3107, Vitacura, Santiago (Chile); Bryden, G. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Danchi, W. [NASA Goddard Space Flight Center, Exoplanets and Stellar Astrophysics, Code 667, Greenbelt, MD 20771 (United States); Liseau, R. [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, SE-43992, Onsala (Sweden); Mora, A. [ESA-ESAC Gaia SOC, P.O. Box 78, E-28691 Villanueva de la Canada, Madrid (Spain); Pilbratt, G. L., E-mail: krivov@astro.uni-jena.de [ESA Astrophysics and Fundamental Physics Missions Division, ESTEC/SRE-SA, Keplerlaan 1, 2201 AZ Noordwijk (Netherlands); and others

    2013-07-20

    Infrared excesses associated with debris disk host stars detected so far peak at wavelengths around {approx}100 {mu}m or shorter. However, 6 out of 31 excess sources studied in the Herschel Open Time Key Programme, DUNES, have been seen to show significant-and in some cases extended-excess emission at 160 {mu}m, which is larger than the 100 {mu}m excess. This excess emission has been attributed to circumstellar dust and has been suggested to stem from debris disks colder than those known previously. Since the excess emission of the cold disk candidates is extremely weak, challenging even the unrivaled sensitivity of Herschel, it is prudent to carefully consider whether some or even all of them may represent unrelated galactic or extragalactic emission, or even instrumental noise. We re-address these issues using several distinct methods and conclude that it is highly unlikely that none of the candidates represents a true circumstellar disk. For true disks, both the dust temperatures inferred from the spectral energy distributions and the disk radii estimated from the images suggest that the dust is nearly as cold as a blackbody. This requires the grains to be larger than {approx}100 {mu}m, even if they are rich in ices or are composed of any other material with a low absorption in the visible. The dearth of small grains is puzzling, since collisional models of debris disks predict that grains of all sizes down to several times the radiation pressure blowout limit should be present. We explore several conceivable scenarios: transport-dominated disks, disks of low dynamical excitation, and disks of unstirred primordial macroscopic grains. Our qualitative analysis and collisional simulations rule out the first two of these scenarios, but show the feasibility of the third one. We show that such disks can indeed survive for gigayears, largely preserving the primordial size distribution. They should be composed of macroscopic solids larger than millimeters, but smaller

  12. Population-specific life histories contribute to metapopulation viability

    Science.gov (United States)

    Halsey, Samniqueka J.; Bell, Timothy J.; McEachern, A. Kathryn; Pavlovic, Noel B.

    2016-01-01

    Restoration efforts can be improved by understanding how variations in life-history traits occur within populations of the same species living in different environments. This can be done by first understanding the demographic responses of natural occurring populations. Population viability analysis continues to be useful to species management and conservation with sensitivity analysis aiding in the understanding of population dynamics. In this study, using life-table response experiments and elasticity analyses, we investigated how population-specific life-history demographic responses contributed to the metapopulation viability of the Federally threatened Pitcher's thistle (Cirsium pitcheri). Specifically, we tested the following hypotheses: (1) Subpopulations occupying different environments within a metapopulation have independent demographic responses and (2) advancing succession results in a shift from a demographic response focused on growth and fecundity to one dominated by stasis. Our results showed that reintroductions had a positive contribution to the metapopulation growth rate as compared to native populations which had a negative contribution. We found no difference in succession on the contribution to metapopulation viability. In addition, we identified distinct population-specific contributions to metapopulation viability and were able to associate specific life-history demographic responses. For example, the positive impact of Miller High Dunes population on the metapopulation growth rate resulted from high growth contributions, whereas increased time of plant in stasis for the State Park Big Blowout population resulted in negative contributions. A greater understanding of how separate populations respond in their corresponding environment may ultimately lead to more effective management strategies aimed at reducing extinction risk. We propose the continued use of sensitivity analyses to evaluate population-specific demographic influences on

  13. Integrating multi-disciplinary field and laboratory methods to investigate the response and recovery of beach-dune systems in Ireland to extreme events

    Science.gov (United States)

    Farrell, E.; Lynch, K.; Wilkes Orozco, S.; Castro Camba, G.; Scullion, A.

    2017-12-01

    This two year field monitoring project examines the response and recovery of 1.2km of a coastal beach-dune system in the west coast of Ireland (The Maharees, Brandon Bay, Co. Kerry) to storms. The results from this project initiated a larger scale study to assess the long term evolution of Brandon Bay (12km) and patterns of meso-scale rotation. On a bay scale historic shoreline analyses were completed using historic Ordnance Survey maps, aerial photography, and DGPS surveys inputted to the Digital Shoreline Analysis System. These were coupled with a GSTA-wavemeter experiment that collected 410 sediment samples along the beach and nearshore to identify preferred sediment transport pathways along the bay. On a local scale (1.2km) geomorphological changes of the beach and nearshore were monitored using repeated monthly DGPS surveys and drone technology. Topographical data were correlated with atmospheric data obtained from a locally installed automatic weather station, oceanographic data from secondary sources, and photogrammetry using a camera installed at the site collecting pictures every 10 minutes during daylight hours. Changes in surface elevation landward of the foredune from aeolian processes were measured using five pin transects across the dune. The contribution of local blowout dynamics were measured using drone imagery and structure-from-motion technology. The results establish that the average shoreline recession along the 1.2 km site is 72 m during the past 115 years. The topographic surveys illustrate that natural beach building processes initiate system recovery post storms including elevated foreshores and backshores and nearshore sand bar migration across the entire 1.2 km stretch of coastline. In parallel with the scientific work, the local community have mobilized and are working closely with the lead scientists to implement short term coastal management strategies such as signage, information booklets, sand trap fencing, walkways, wooden

  14. Modelling of hydrogen sulfide dispersion from the geothermal power plants of Tuscany (Italy)

    Science.gov (United States)

    Renato, Somma; Domenico, Granieri; Claudia, Troise; Carlo, Terranova; Natale Giuseppe, De; Maria, Pedone

    2017-04-01

    The hydrogen sulfide (H2S) is one of the main gaseous substances contained in deep fluids exploited by geo-thermoelectric plant. Therefore, it is a "waste" pollutant product by plants for energy production. Hydrogen sulfide is perceived by humans at very low concentrations in the air ( 0,008 ppm, World Health Organization, hereafter WHO, 2003) but it becomes odorless in higher concentrations (> 100 ppm, WHO, 2003) and, for values close to the ones lethal (> 500 ppm), produces an almost pleasant smell. The typical concentration in urban areas is effects on human health. We applied the Eulerian code DISGAS (DISpersion of GAS) to investigate the dispersion of the hydrogen sulfide (H2S) from 32 geothermal power plants (out of 35 active) belonging to the geothermal districts of Larderello, Travale-Radicondoli and Monte Amiata, in Tuscany (Italy). DISGAS code has simulated scenarios consistent with the prevailing wind conditions, estimating reasonable H2S concentrations for each area, and for each active power plant. The results suggest that H2S plumes emitted from geothermal power plants are mainly concentrated around the stacks of emission (H2S concentration up to 1100 ug/m3) and rapidly dilute along the dominant local wind direction. Although estimated values of air H2S concentrations are orders of magnitude higher than in unpolluted areas, they do not indicate an immediate health risk for nearby communities, under the more frequent local atmospheric conditions. Starting from the estimated values, validated by measurements in the field, we make some considerations about the environmental impact of the H2S emission in all the geothermal areas of the Tuscany region. Furthermore, this study indicates the potential of DISGAS as a tool for an improved understanding of the atmospheric and environmental impacts of the H2S continuous degassing from geothermal plants but also its potential for reliable prediction of H2S pollution in case of unexpected events, like the blowout

  15. Sensitivity of the deep-sea amphipod Eurythenes gryllus to chemically dispersed oil.

    Science.gov (United States)

    Olsen, Gro Harlaug; Coquillé, Nathalie; Le Floch, Stephane; Geraudie, Perrine; Dussauze, Matthieu; Lemaire, Philippe; Camus, Lionel

    2016-04-01

    In the context of an oil spill accident and the following oil spill response, much attention is given to the use of dispersants. Dispersants are used to disperse an oil slick from the sea surface into the water column generating a cloud of dispersed oil droplets. The main consequence is an increasing of the sea water-oil interface which induces an increase of the oil biodegradation. Hence, the use of dispersants can be effective in preventing oiling of sensitive coastal environments. Also, in case of an oil blowout from the seabed, subsea injection of dispersants may offer some benefits compared to containment and recovery of the oil or in situ burning operation at the sea surface. However, biological effects of dispersed oil are poorly understood for deep-sea species. Most effects studies on dispersed oil and also other oil-related compounds have been focusing on more shallow water species. This is the first approach to assess the sensitivity of a macro-benthic deep-sea organism to dispersed oil. This paper describes a toxicity test which was performed on the macro-benthic deep-sea amphipod (Eurythenes gryllus) to determine the concentration causing lethality to 50% of test individuals (LC50) after an exposure to dispersed Brut Arabian Light (BAL) oil. The LC50 (24 h) was 101 and 24 mg L(-1) after 72 h and 12 mg L(-1) at 96 h. Based on EPA scale of toxicity categories to aquatic organisms, an LC50 (96 h) of 12 mg L(-1) indicates that the dispersed oil was slightly to moderately toxic to E. gryllus. As an attempt to compare our results to others, a literature study was performed. Due to limited amount of data available for dispersed oil and amphipods, information on other crustacean species and other oil-related compounds was also collected. Only one study on dispersed oil and amphipods was found, the LC50 value in this study was similar to the LC50 value of E. gryllus in our study. Since toxicity data are important input to risk assessment and net environmental

  16. SEM Characterization of Extinguished Grains from Plasma-Ignited M30 Charges

    Science.gov (United States)

    Kinkennon, A.; Birk, A.; DelGuercio, M.; Kaste, P.; Lieb, R.; Newberry, J.; Pesce-Rodriguez, R.; Schroeder, M.

    2000-01-01

    M30 propellant grains that had been ignited in interrupted closed bomb experiments were characterize by scanning electron microscopy (SEM). Previous chemical analysis of extinguished grains had given no indications of plasma-propellant chemical interactions that could explain the increased burning rates that had been previously observed in full-pressure closed bomb experiments. (This does not mean that there is no unique chemistry occurring with plasma ignition. It may occur very early in the ignition event and then become obscured by the burning chemistry.) In this work, SEM was used to look at grain morphologies to determine if there were increases in the surface areas of the plasma-ignited grains which would contribute to the apparent increase in the burning rate. Charges were made using 30 propellant grains (approximately 32 grams) stacked in two tiers and in two concentric circles around a plastic straw. Each grain was notched so that, when the grains were expelled from the bomb during extinguishment, it could be determined in which tier and which circle each grain was originally packed. Charges were ignited in a closed bomb by either a nickel wire/Mylar-capillary plasma or black powder. The bomb contained a blowout disk that ruptured when the pressure reached 35 MPa, and the propellant was vented into a collection chamber packed with polyurethane foam. SEM analysis of the grains fired with a conventional black powder igniter showed no signs of unusual burning characteristics. The surfaces seemed to be evenly burned on the exteriors of the grains and in the perforations. Grains that had been subjected to plasma ignition, however, had pits, gouges, chasms, and cracks in the surfaces. The sides of the grains closest to the plasma had the greatest amount of damage, but even surfaces facing the outer wall of the bomb had small pits. The perforations contained gouges and abnormally burned regions (wormholes) that extended into the web. The SEM photos indicated that

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

    International Nuclear Information System (INIS)

    Gilkey, Amy P.; Hansen, Clifford W.; Schatz, John F.; Rudeen, David Keith; Lord, David L.

    2006-01-01

    This report presents a model to estimate the spallings releases for the Waste Isolation Pilot Plant Performance Assessment (WIPP PA). A spallings release in the context of WIPP PA refers to a portion of the solid waste transported from the subsurface repository to the ground surface due to inadvertent oil or gas drilling into the WIPP repository at some time after site closure. Some solid waste will be removed by the action of the drillbit and drilling fluid; this waste is referred to as cuttings and cavings. If the repository is pressurized above hydrostatic at the time of intrusion, solid waste material local to the borehole may be subject to mechanical failure and entrainment in high-velocity gases as the repository pressure is released to the borehole. Solid material that fails and is transported into the wellbore and thus to the surface comprise the spallings releases. The spallings mechanism is analogous to a well blowout in the modern oil and gas drilling industry. The current spallings conceptual model and associated computer code, DRSPALL, were developed for the 2004 recertification because the prior spallings model used in the 1996 WIPP Compliance Certification Application (CCA) was judged by an independent peer review panel as inadequate (DOE 1996, 9.3.1). The current conceptual model for spallings addresses processes that take place several minutes before and after a borehole intrusion of a WIPP waste room. The model couples a pipe-flow wellbore model with a porous flow repository model, allowing high-pressure gas to flow from the repository to the wellbore through a growing cavity region at the well bottom. An elastic stress model is applied to the porous solid domain that allows for mechanical failure of repository solids if local tensile stress exceeds the tensile strength of the waste. Tensile-failed solids may be entrained into the wellbore flow stream by a fluidized bed model, in which case they are ultimately transported to the land surface

  18. Quantifying Methane Flux from a Prominent Seafloor Crater with Water Column Imagery Filtering and Bubble Quantification Techniques

    Science.gov (United States)

    Mitchell, G. A.; Gharib, J. J.; Doolittle, D. F.

    2015-12-01

    Methane gas flux from the seafloor to atmosphere is an important variable for global carbon cycle and climate models, yet is poorly constrained. Methodologies used to estimate seafloor gas flux commonly employ a combination of acoustic and optical techniques. These techniques often use hull-mounted multibeam echosounders (MBES) to quickly ensonify large volumes of the water column for acoustic backscatter anomalies indicative of gas bubble plumes. Detection of these water column anomalies with a MBES provides information on the lateral distribution of the plumes, the midwater dimensions of the plumes, and their positions on the seafloor. Seafloor plume locations are targeted for visual investigations using a remotely operated vehicle (ROV) to determine bubble emission rates, venting behaviors, bubble sizes, and ascent velocities. Once these variables are measured in-situ, an extrapolation of gas flux is made over the survey area using the number of remotely-mapped flares. This methodology was applied to a geophysical survey conducted in 2013 over a large seafloor crater that developed in response to an oil well blowout in 1983 offshore Papua New Guinea. The site was investigated by multibeam and sidescan mapping, sub-bottom profiling, 2-D high-resolution multi-channel seismic reflection, and ROV video and coring operations. Numerous water column plumes were detected in the data suggesting vigorously active vents within and near the seafloor crater (Figure 1). This study uses dual-frequency MBES datasets (Reson 7125, 200/400 kHz) and ROV video imagery of the active hydrocarbon seeps to estimate total gas flux from the crater. Plumes of bubbles were extracted from the water column data using threshold filtering techniques. Analysis of video images of the seep emission sites within the crater provided estimates on bubble size, expulsion frequency, and ascent velocity. The average gas flux characteristics made from ROV video observations is extrapolated over the number

  19. Effects of Combustion-Induced Vortex Breakdown on Flashback Limits of Syngas-Fueled Gas Turbine Combustors

    Energy Technology Data Exchange (ETDEWEB)

    Ahsan Choudhuri

    2011-03-31

    Turbine combustors of advanced power systems have goals to achieve very low pollutants emissions, fuel variability, and fuel flexibility. Future generation gas turbine combustors should tolerate fuel compositions ranging from natural gas to a broad range of syngas without sacrificing operational advantages and low emission characteristics. Additionally, current designs of advanced turbine combustors use various degrees of swirl and lean premixing for stabilizing flames and controlling high temperature NOx formation zones. However, issues of fuel variability and NOx control through premixing also bring a number of concerns, especially combustor flashback and flame blowout. Flashback is a combustion condition at which the flame propagates upstream against the gas stream into the burner tube. Flashback is a critical issue for premixed combustor designs, because it not only causes serious hardware damages but also increases pollutant emissions. In swirl stabilized lean premixed turbine combustors onset of flashback may occur due to (i) boundary layer flame propagation (critical velocity gradient), (ii) turbulent flame propagation in core flow, (iii) combustion instabilities, and (iv) upstream flame propagation induced by combustion induced vortex breakdown (CIVB). Flashback due to first two foregoing mechanisms is a topic of classical interest and has been studied extensively. Generally, analytical theories and experimental determinations of laminar and turbulent burning velocities model these mechanisms with sufficient precision for design usages. However, the swirling flow complicates the flashback processes in premixed combustions and the first two mechanisms inadequately describe the flashback propensity of most practical combustor designs. The presence of hydrogen in syngas significantly increases the potential for flashback. Due to high laminar burning velocity and low lean flammability limit, hydrogen tends to shift the combustor operating conditions towards

  20. Combustion Characteristics and Performance of Low-Swirl Injectors with Natural Gas and Alternative Fuels At Elevated Pressures and Temperatures

    Science.gov (United States)

    Beerer, David Joseph

    Stationary power-generating gas turbines in the United States have historically been fueled with natural gas, but due to its increasing price and the need to reduce carbon emissions, interest in alternative fuels is increasing. In order to effectively operate engines with these fuels their combustion characteristics need be well understood, especially at elevated pressures and temperatures. In this dissertation, the performance of blends of natural gas / methane with hydrogen and carbon dioxide, to simulate syngas and biogas, are evaluated in a model low-swirl stabilized combustor inside an optically accessible high-pressure vessel. The flashback and lean blow out limits, along with pollutant emissions, flow field, and turbulent displacement flame speeds, are measured as a function of fuel composition, pressure, inlet temperature, firing temperature, and flow rate in the range from 1 to 8 atm, 294 to 600K, 1350 to 1950K, and 20 to 60 m/s, respectively. These properties are quantified as a function of the inlet parameters. The lean blow-out limits are independent of pressure and inlet temperature but are weakly dependent on velocity. NOX emissions for both fuels were found to be exponentially dependent upon firing temperature, but emissions for the high-hydrogen flames were consistently higher than those of natural gas flames. The flashback limits for a 90%/10% (by volume) hydrogen/methane mixture increase with velocity and inlet temperature, but decrease with pressure. Correspondingly, the flame position progresses toward the combustor nozzle with increasing pressure and flame temperature, but away with increasing inlet temperature and velocity. Flashback occurred when the leading edge of the flame entered the nozzle. Local displacement turbulent flame speeds scale linearly with the turbulent fluctuating velocities, u', at the leading edge of the flame. Turbulent flame speeds for high-hydrogen fuels are twice that of natural gas for the same inlet conditions. The

  1. Grande Ronde Endemic Spring Chinook Salmon Supplementation Program: Facility Operations and Maintenance, 2002 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    McLean, Michael L.; Seeger, Ryan; Hewitt, Laurie (Confederated Tribes of the Umatilla Indian Reservation, Pendleton, OR)

    2003-03-01

    area, and complete overhaul of 2 travel trailers. Montgomery-Watson-Harza (MWH) completed construction activities to both acclimation facilities and the Catherine Creek Adult Collection Facility (CCACF) in 2002. Their work included installation of larger intake manifold, new inflow valves on each raceway, new manifold blowout valve, and handrails and grating around raceways and the weir.

  2. Estuarine development and early Holocene transgression across an aeolianite substrate, Caesarea, central Israel

    Science.gov (United States)

    Goff, John A.; Austin, James A.; Goodman-Tchernov, Beverly N.

    2018-04-01

    Estuaries are important features on the coastal landscape due to their potential for rich, diverse, and abundant resources. The modern coast of the southeast Mediterranean is largely devoid of estuaries except in rare circumstances where ample sands are delivered to the shore, such as east of the Nile Delta. Whether or not today's condition is reflective of that present during lower sea-levels is greatly speculative in part due to a dearth of high-resolution sub-surface mapping in the shallower (sea-level curves, was a period of rapid ( 1-1.7 cm/yr) sea-level rise. Now-submerged aeolianite ridges (locally referred to as 'kurkar'), cemented aeolian deposits formed during pre-Last-Glacial-Maximum (LGM) seaward advance (regression) of the coastline, likely provided some offshore barrier for estuarine development. These were insufficient, however, to account for all the estuarine deposition interpreted, leading us to hypothesize that sand-constructed barrier islands were also present as sea-level rose during the Holocene. This supply of sand, clearly greater than what is evident today, could have originated from sea-level rise phase eroding Nile Delta sediments transported northward by littoral currents, or from increased output from local rivers during wetter climatic conditions. We also observe a transition from linear, shore-parallel aeolianite ridge morphology features on land and in shallow water, to nested, arcuate features below 30 mbsl. Whereas the linear ridges are thought to be coastal foredune remnants abandoned by the retreating shoreline, the arcuate forms resemble fossil parabolic (blowout) dunes. Based on the recent initiation of parabolic dunes on Cape Cod following anthropogenic denudation of forests there, we suggest that climate aridification approaching the LGM could have denuded vegetation along the Israeli coast, enabling parabolic dune formation landward of the coastal foredunes which were later preserved via cementation. Understanding the past

  3. Seismic and structural characterization of the fluid bypass system using 3D and partial stack seismic from passive margin: inside the plumbing system.

    Science.gov (United States)

    Iacopini, David; Maestrelli, Daniele; Jihad, Ali; Bond, Clare; Bonini, Marco

    2017-04-01

    In recent years enormous attention has been paid to the understanding of the process and mechanism controlling the gas seepage and more generally the fluid expulsion affecting the earth system from onshore to offshore environment. This is because of their demonstrated impact to our environment, climate change and during subsea drilling operation. Several example from active and paleo system has been so far characterized and proposed using subsurface exploration, geophysical and geochemical monitoring technology approaches with the aims to explore what trigger and drive the overpressure necessary maintain the fluid/gas/material expulsion and what are the structure that act as a gateway for gaseous fluid and unconsolidated rock. In this contribution we explore a series of fluid escape structure (ranging from seepage pipes to large blowout pipes structure of km length) using 3D and partial stack seismic data from two distinctive passive margin from the north sea (Loyal field, West Shetland) and the Equatorial Brazil (Ceara' Basin). We will focuses on the characterization of the plumbing system internal architecture and, for selected example, exploring the AVO response (using partial stack) of the internal fluid/unconsolidated rock. The detailed seismic mapping and seismic attributes analysis of the conduit system helped us to recover some detail from the signal response of the chimney internal structures. We observed: (1) small to medium seeps and pipes following structural or sedimentary discontinuities (2) large pipes (probably incipient mud volcanoes) and blowup structures propagating upward irrespective of pre-existing fault by hydraulic fracturing and assisted by the buoyancy of a fluidised and mobilised mud-hydrocarbon mixture. The reflector termination observed inside the main conduits, the distribution of stacked bright reflectors and the AVO analysis suggests an evolution of mechanisms (involving mixture of gas, fluid and probably mud) during pipe birth and

  4. Herschel's "Cold Debris Disks": Background Galaxies or Quiescent Rims of Planetary Systems?

    Science.gov (United States)

    Krivov, A. V.; Eiroa, C.; Loehne, T.; Marshall, J. P.; Montesinos, B.; DelBurgo, C.; Absil, O.; Ardila, D.; Augereau, J.-C.; Bayo, A.; hide

    2013-01-01

    Infrared excesses associated with debris disk host stars detected so far peak at wavelengths around approx, 100 micron or shorter. However, 6 out of 31 excess sources studied in the Herschel Open Time Key Programme, DUNES, have been seen to show significant-and in some cases extended-excess emission at 160 micron, which is larger than the 100 micron excess. This excess emission has been attributed to circumstellar dust and has been suggested to stem from debris disks colder than those known previously. Since the excess emission of the cold disk candidates is extremely weak, challenging even the unrivaled sensitivity of Herschel, it is prudent to carefully consider whether some or even all of them may represent unrelated galactic or extragalactic emission, or even instrumental noise. We re-address these issues using several distinct methods and conclude that it is highly unlikely that none of the candidates represents a true circumstellar disk. For true disks, both the dust temperatures inferred from the spectral energy distributions and the disk radii estimated from the images suggest that the dust is nearly as cold as a blackbody. This requires the grains to be larger than approx. 100 micron, even if they are rich in ices or are composed of any other material with a low absorption in the visible. The dearth of small grains is puzzling, since collisional models of debris disks predict that grains of all sizes down to several times the radiation pressure blowout limit should be present. We explore several conceivable scenarios: transport-dominated disks, disks of low dynamical excitation, and disks of unstirred primordial macroscopic grains. Our qualitative analysis and collisional simulations rule out the first two of these scenarios, but show the feasibility of the third one. We show that such disks can indeed survive for gigayears, largely preserving the primordial size distribution. They should be composed of macroscopic solids larger than millimeters, but

  5. [Complex maxillofacial trauma: diagnostic contribution of multiplanar and tridimensional spiral CT imaging].

    Science.gov (United States)

    Preda, L; La Fianza, A; Di Maggio, E M; Dore, R; Schifino, M R; Mevio, E; Campani, R

    1998-09-01

    Adequate radiologic assessment of the maxillofacial trauma patient is the basis for planning reparative surgery. We investigated the yield of the integration of axial CT with multiplanar (MP) and three-dimensional (3D) reconstructions with the Spiral technique. Thirty-five patients (21 men and 14 women, mean age: 31.2 years) with complex maxillofacial traumas were submitted to Spiral CT. Images were acquired with 2-3-mm collimation, 1:1 to 2:1 pitch, 210 mAs, 120 kV, 15-24 s Spiral scan, RI = 1. 3D reconstructions were always obtained and used to guide MPRs targeted on the single injury. The examinations were retrospectively given a score, namely 1 if 3D and MPR yielded no more important diagnostic information than axial CT, 2 if 3D and MPR permitted better detailing of some axial CT findings and thus improved image reading, and 3 if 3D and MPR showed new injuries missed on axial images. Then, a radiologist and a maxillofacial surgeon reviewed the 3D images together only to assess in which cases they were useful to optimize surgical planning. Nine cases (25.7%) scored 1, seventeen (48.6%) scored 2 and nine (25.7%) scored 3. MP and 3D reconstructions were useful or determinant (2 + 3) in over 74% of cases. 3D images made surgical planning easier in 15 of 32 surgical patients (46.8%), allowing the surgeon a better panoramic view of the complex fracture. The greatest advantage of multiplanar imaging is the improved depiction of skeletal injuries along a horizontal plane, paralleling that of axial scans. The depiction of fractures of cribrum and of orbital roof and floor was particularly useful from a clinical viewpoint. MPRs clearly depicted herniation and incarceration of the lower rectus muscle in blow-out fractures. MP and 3D reconstructions better defined the presence and grade of displaced bone fragments in nearly vertical structures, such as the upward branches and coronoid apophysis of the mandible. 3D images alone never showed any more fractures than those

  6. 'Orbital volume restoration rate after orbital fracture'; a CT-based orbital volume measurement for evaluation of orbital wall reconstructive effect.

    Science.gov (United States)

    Wi, J M; Sung, K H; Chi, M

    2017-05-01

    PurposeTo evaluate the effect of orbital reconstruction and factors related to the effect of orbital reconstruction by assessing of orbital volume using orbital computed tomography (CT) in cases of orbital wall fracture.MethodsIn this retrospective study, 68 patients with isolated blowout fractures were evaluated. The volumes of orbits and herniated orbital tissues were determined by CT scans using a three-dimensional reconstruction technique (the Eclipse Treatment Planning System). Orbital CT was performed preoperatively, immediately after surgery, and at final follow ups (minimum of 6 months). We evaluated the reconstructive effect of surgery making a new formula, 'orbital volume reconstruction rate' from orbital volume differences between fractured and contralateral orbits before surgery, immediately after surgery, and at final follow up.ResultsMean volume of fractured orbits before surgery was 23.01±2.60 cm 3 and that of contralateral orbits was 21.31±2.50 cm 3 (P=0.005). Mean volume of the fractured orbits immediately after surgery was 21.29±2.42 cm 3 , and that of the contralateral orbits was 21.33±2.52 cm 3 (P=0.921). Mean volume of fractured orbits at final follow up was 21.50±2.44 cm 3 , and that of contralateral orbits was 21.32±2.50 cm 3 (P=0.668). The mean orbital volume reconstruction rate was 100.47% immediately after surgery and 99.17% at final follow up. No significant difference in orbital volume reconstruction rate was observed with respect to fracture site or orbital implant type. Patients that underwent operation within 14 days of trauma had a better reconstruction rate at final follow up than patients who underwent operation over 14 days after trauma (P=0.039).ConclusionComputer-based measurements of orbital fracture volume can be used to evaluate the reconstructive effect of orbital implants and provide useful quantitative information. Significant reduction of orbital volume is observed immediately after orbital wall

  7. Coupling of Large Eddy Simulations with Meteorological Models to simulate Methane Leaks from Natural Gas Storage Facilities

    Science.gov (United States)

    Prasad, K.

    2017-12-01

    compared with results obtained from spectrometer data to estimate the temporally evolving methane flux during the Aliso Canyon blowout.

  8. Investigation on the flame dynamics of meso-combustors

    Science.gov (United States)

    Ahmed, Mahbub

    Miniature heat engines burning hydrogen and hydrocarbon fuels have significantly higher energy densities compared to conventional lithium batteries and thus will play an essential role in the portable production of power for future electronics, remote sensors, and micro aerial vehicles. Additionally, miniature heat engines will tremendously benefit next generation of environmental technologies such as steam reforming, ammonia decomposition and fuel cells. Successful miniaturization of heat engine components demand a more complete and broader understanding of micro-fluid dynamics and micro-combustion phenomena associated with the combustor design. This dissertation is aimed at investigating the details of the micro-mixing dynamics and the combustion behavior of the meso-combustor and to create fundamental understanding of physics based design methodology. The primary goals of the project are (i) to develop an understanding of fuel-air mixing inside a meso-combustor, (ii) to develop an understanding of the flame stability (flame quenching and velocity blowout) criteria of a meso-combustor, (iii) to understand the thermal behavior of the meso-combustor, and (iv) to correlate these with combustor operating conditions such as the Reynolds number, equivalent ratio, and thermal power etc. The present study shows that adequate mixing of fuel and air is achievable in millimeter scale combustors. Both computed results and experimental measurements of iso-thermal (non-burning) flows at different mixing configurations indicate that the laminar burning velocity remains higher than the local flow velocities in most of the combustor locations to support stable flame propagations. Stable flames of hydrogen are achieved for all mixing and flow configurations. The combustion of methane with air as oxidizer in the combustors is unreliable. However, highly stable combustion of methane at various mixing and flow conditions is achieved when pure oxygen is used as an oxidizer. The

  9. Combustion control and sensors: a review

    International Nuclear Information System (INIS)

    Docquier, N.; Candel, S.

    2002-01-01

    There is an increased interest in the application of control to combustion. The objective is to optimize combustor operation, monitor the process and alleviate instabilities and their severe consequences. One wishes to improve the system performance, for example by reducing the levels of pollutant emissions or by smoothing the pattern factor at the combustor exhaust. In other cases, the aim is to extend the stability domain by reducing the level of oscillation induced by coupling between resonance modes and combustion. As combustion systems have to meet increasingly more demanding air pollution standards, their design and operation becomes more complex. The trend towards reduced NO x levels has led to new developments in different fields. Automotive engines and gas turbine combustors are considered in this article. In the first case, complex exhaust aftertreatment is being applied and dedicated engine control systems are required to ensure and maintain high pollutant conversion efficiency. For gas turbines, premixed combustors, which operate at lower local temperatures than conventional systems have been designed. In both cases, monitoring and control of the operating point of the process have to be achieved with great precision to obtain the full benefits of the NO x reduction scheme. For premixed combustors operating near the lean stability limit, the flame is more susceptible to blowout, oscillation or flashback. Research is now carried out to reduce these dynamical problems with passive and active control methods. In addition to a broad range of fundamental problems raised by Active Combustion Control (ACC) and Operating Point Control (OPC), there are important technological issues. This paper contains a review of some facets of combustion control and focuses on the sensors that take or could take part to combustion control solutions. The current status of ACC and OPC is presented together with the associated control concepts. The state of the art in sensors is

  10. Risk Analysis of Flare Flame-out Condition in a Gas Process Facility Analyse des risques des conditions d’extinction de torche au sein d’une installation de traitement de gaz

    Directory of Open Access Journals (Sweden)

    Zadakbar O.

    2011-02-01

    Full Text Available Flaring is a common method of disposal of flammable waste gases in the downstream industries. Flare flame out (flame lift-off or blow-outs often occurs causing toxic vapors to discharge. The toxic gases released may have hazardous effects on the surrounding environment. To study the effect of inhalation exposure of these toxic gases on human health, the four steps of the EPA (Environmental Protection Agency framework with the field data to quantify the cancer and non-cancer health risks are integrated in this paper. As a part of exposure assessment, gas dispersion modeling using AERMOD and UDM-PHAST is applied in two different conditions of normal flaring and flare flame out during a particular climate condition in Khangiran region. Recommendations to avoid flare flame out conditions are also presented here. Le torchage est un procédé courant d’élimination des gaz résiduaires inflammables dans les industries de traitement. L’extinction de la torche (par décollage ou soufflage de flamme provoque souvent une émission de vapeurs toxiques. Ces gaz toxiques libérés peuvent présenter des effets dangereux sur le milieu environnant. Pour étudier l’effet d’une exposition par inhalation de ces gaz toxiques sur la santé, cet article croise les quatre étapes de la démarche de l’EPA (Environmental Protection Agency, Agence de protection de l’environnement avec les données d’exploitation afin de quantifier le risque sanitaire cancérologique et non cancérologique. Dans le cadre de l’estimation d’exposition, une modélisation de dispersion des gaz utilisant AERMOD et UDM-PHAST est évaluée dans deux configurations différentes de torchage normal et d’extinction de torche à l’occasion de conditions climatiques particulières dans la région du Khangiran. L’article propose également des recommandations destinées à éviter les conditions d’une extinction de flamme de torche.

  11. Experimental study of unsteady heat release in an unstable single element Lean Direct Injection (LDI) gas turbine combustor

    Science.gov (United States)

    Lakshmanan, Varun S.

    In an effort to curb emissions from gas turbine engines, many low emission engine concepts have been developed. Among the most promising of these is the LDI (Lean Direct Injection). These systems operate at relatively low equivalence ratios close to blowout and are prone to instabilities. Combustion instabilities can reduce the life of the combustor by causing large pressure fluctuations and enhanced heat release to the walls of the combustor and reduce the efficiency of the engines. The understanding of combustion instabilities is vital to the implementation of such systems. Combustion instabilities are studied in an self-excited single element gas turbine combustor that uses an LDI element for fuel injection at elevetaed chamber pressures. The LDI combustor uses a swirler to ensure mixing of the air and the fuel and expansion of the swirl through a pressure swirl venturi to create a swirl stabilized flame. This project aims to study the heat release modes that occur in the combustor through measurement of light emissions from the flame using photodiodes that are sensitive to wavelengths of light produced by the flame. These are used along with high frequency pressure transducers. The focus is on the flame behavior in the diverging section of the venturi where the swirl is expanded and the flame starts since optic access cannot be obtained in this section. The use of photodiodes also facilitates the study of hydrodynamic modes that occur in the combustor alongside the thermoacoustics. A section which could accommodate the photodiodes was designed and installed on the LDI test rig in the Gas Turbine Cell at Maurice J Zucrow Propulsion Labs at Purdue University. The combustor was tested with this section and dynamic data was obtained from the pressure transducers and the photodiodes for a range of inlet air temperatures and range of equivalence ratios for each inlet air temperature. The dominant instability modes in both sets of data were analyzed and are presented

  12. Fuel Flexible Combustion Systems for High-Efficiency Utilization of Opportunity Fuels in Gas Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Venkatesan, Krishna

    2011-11-30

    The purpose of this program was to develop low-emissions, efficient fuel-flexible combustion technology which enables operation of a given gas turbine on a wider range of opportunity fuels that lie outside of current natural gas-centered fuel specifications. The program encompasses a selection of important, representative fuels of opportunity for gas turbines with widely varying fundamental properties of combustion. The research program covers conceptual and detailed combustor design, fabrication, and testing of retrofitable and/or novel fuel-flexible gas turbine combustor hardware, specifically advanced fuel nozzle technology, at full-scale gas turbine combustor conditions. This project was performed over the period of October 2008 through September 2011 under Cooperative Agreement DE-FC26-08NT05868 for the U.S. Department of Energy/National Energy Technology Laboratory (USDOE/NETL) entitled "Fuel Flexible Combustion Systems for High-Efficiency Utilization of Opportunity Fuels in Gas Turbines". The overall objective of this program was met with great success. GE was able to successfully demonstrate the operability of two fuel-flexible combustion nozzles over a wide range of opportunity fuels at heavy-duty gas turbine conditions while meeting emissions goals. The GE MS6000B ("6B") gas turbine engine was chosen as the target platform for new fuel-flexible premixer development. Comprehensive conceptual design and analysis of new fuel-flexible premixing nozzles were undertaken. Gas turbine cycle models and detailed flow network models of the combustor provide the premixer conditions (temperature, pressure, pressure drops, velocities, and air flow splits) and illustrate the impact of widely varying fuel flow rates on the combustor. Detailed chemical kinetic mechanisms were employed to compare some fundamental combustion characteristics of the target fuels, including flame speeds and lean blow-out behavior. Perfectly premixed combustion experiments were conducted to

  13. 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

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

    International Nuclear Information System (INIS)

    Himes, D.A.

    1998-01-01

    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

  15. 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

  16. RNA-Seq reveals complex genetic response to deepwater horizon oil release in Fundulus grandis

    Directory of Open Access Journals (Sweden)

    Garcia Tzintzuni I

    2012-09-01

    Full Text Available Abstract Background The release of oil resulting from the blowout of the Deepwater Horizon (DH drilling platform was one of the largest in history discharging more than 189 million gallons of oil and subject to widespread application of oil dispersants. This event impacted a wide range of ecological habitats with a complex mix of pollutants whose biological impact is still not yet fully understood. To better understand the effects on a vertebrate genome, we studied gene expression in the salt marsh minnow Fundulus grandis, which is local to the northern coast of the Gulf of Mexico and is a sister species of the ecotoxicological model Fundulus heteroclitus. To assess genomic changes, we quantified mRNA expression using high throughput sequencing technologies (RNA-Seq in F. grandis populations in the marshes and estuaries impacted by DH oil release. This application of RNA-Seq to a non-model, wild, and ecologically significant organism is an important evaluation of the technology to quickly assess similar events in the future. Results Our de novo assembly of RNA-Seq data produced a large set of sequences which included many duplicates and fragments. In many cases several of these could be associated with a common reference sequence using blast to query a reference database. This reduced the set of significant genes to 1,070 down-regulated and 1,251 up-regulated genes. These genes indicate a broad and complex genomic response to DH oil exposure including the expected AHR-mediated response and CYP genes. In addition a response to hypoxic conditions and an immune response are also indicated. Several genes in the choriogenin family were down-regulated in the exposed group; a response that is consistent with AH exposure. These analyses are in agreement with oligonucleotide-based microarray analyses, and describe only a subset of significant genes with aberrant regulation in the exposed set. Conclusion RNA-Seq may be successfully applied to feral and

  17. Electron acceleration and generation of high-brilliance x-ray radiation in kilojoule, subpicosecond laser-plasma interactions

    Directory of Open Access Journals (Sweden)

    J. Ferri

    2016-10-01

    Full Text Available Petawatt, picosecond laser pulses offer rich opportunities in generating synchrotron x-rays. This paper concentrates on the regimes accessible with the PETAL laser, which is a part of the Laser Megajoule (LMJ facility. We explore two physically distinct scenarios through Particle-in-Cell simulations. The first one realizes in a dense plasma, such that the period of electron Langmuir oscillations is much shorter than the pulse duration. Hallmarks of this regime are longitudinal breakup (“self-modulation” of the picosecond-scale laser pulse and excitation of a rapidly evolving broken plasma wake. It is found that electron beams with a charge of several tens of nC can be obtained, with a quasi-Maxwellian energy distribution extending to a few-GeV level. In the second scenario, at lower plasma densities, the pulse is shorter than the electron plasma period. The pulse blows out plasma electrons, creating a single accelerating cavity, while injection on the density downramp creates a nC quasi-monoenergetic electron bunch within the cavity. This bunch accelerates without degradation beyond 1 GeV. The x-ray sources in the self-modulated regime offer a high number of photons (∼10^{12} with the slowly decaying energy spectra extending beyond 60 keV. In turn, quasimonoenergetic character of the electron beam in the blowout regime results in the synchrotron-like spectra with the critical energy around 10 MeV and a number of photons >10^{9}. Yet, much smaller source duration and transverse size increase the x-ray brilliance by more than an order of magnitude against the self-modulated case, also favoring high spatial and temporal resolution in x-ray imaging. In all explored cases, accelerated electrons emit synchrotron x-rays of high brilliance, B>10^{20}  photons/s/mm^{2}/mrad^{2}/0.1%BW. Synchrotron sources driven by picosecond kilojoule lasers may thus find an application in x-ray diagnostics on such facilities such as the LMJ or National

  18. Energy Spread Reduction of Electron Beams Produced via Laser Wake

    Energy Technology Data Exchange (ETDEWEB)

    Pollock, Bradley Bolt [Univ. of California, San Diego, CA (United States)

    2012-01-01

    Laser wakefield acceleration of electrons holds great promise for producing ultra-compact stages of GeV scale, high quality electron beams for applications such as x-ray free electron lasers and high energy colliders. Ultra-high intensity laser pulses can be self-guided by relativistic plasma waves over tens of vacuum diffraction lengths, to give >1 GeV energy in cm-scale low density plasma using ionization-induced injection to inject charge into the wake at low densities. This thesis describes a series of experiments which investigates the physics of LWFA in the self-guided blowout regime. Beginning with high density gas jet experiments the scaling of the LWFA-produced electron beam energy with plasma electron density is found to be in excellent agreement with both phenomenological theory and with 3-D PIC simulations. It is also determined that self-trapping of background electrons into the wake exhibits a threshold as a function of the electron density, and at the densities required to produce electron beams with energies exceeding 1 GeV a different mechanism is required to trap charge into low density wakes. By introducing small concentrations of high-Z gas to the nominal He background the ionization-induced injection mechanism is enabled. Electron trapping is observed at densities as low as 1.3 x 1018 cm-3 in a gas cell target, and 1.45 GeV electrons are demonstrated for the first time from LWFA. This is currently the highest electron energy ever produced from LWFA. The ionization-induced trapping mechanism is also shown to generate quasi-continuous electron beam energies, which is undesirable for accelerator applications. By limiting the region over which ionization-induced trapping occurs, the energy spread of the electron beams can be controlled. The development of a novel two-stage gas cell target provides the capability to tailor the gas composition in the longitudinal direction, and confine the trapping process to occur only in a

  19. Photochemical fate of solvent constituents of Corexit oil dispersants.

    Science.gov (United States)

    Kover, Stephanie C; Rosario-Ortiz, Fernando L; Linden, Karl G

    2014-04-01

    In 2010, an estimated 1.87 million gallons (7079 cubic meters) of chemical dispersants were applied to open ocean waters in the Gulf of Mexico as part of the response to the Deepwater Horizon blowout. This unprecedented volume of dispersant application highlighted the importance of dispersant chemical formulations, raising questions of dispersant fate and transport in the open ocean and spurring research into formulation improvements. The research presented here elucidates the contribution of photolytic processes to the degradation of two solvent constituents of these dispersant mixtures: propylene glycol (PG) and 2-butoxyethanol (2-BE). A series of photodegradation experiments were conducted to determine the contribution of direct photolysis and indirect photolysis via hydroxyl radical (HO) to compound degradation. Experiments were performed using both deep UV light sources (low pressure (LP) and medium pressure (MP) mercury vapor ultraviolet (UV) lamps) and a solar simulator. Sample matrices included ultrapure water, nitrate amended water, hydrogen peroxide (H2O2) spiked water, Gulf of Mexico seawater, and a surface water from Boulder, CO. Experiments included determination of the molar absorption coefficients (ε) and the HO reaction rate constants (kHO) of the individual compounds. Data illustrated that significant direct photolysis of either PG or 2-BE from sunlight is unlikely. The kHO for PG and 2-BE were determined to be 6.15 × 10(8) M(-1) s(-1) and 1.15 × 10(9) M(-1) s(-1), respectively. Solar simulation and UV experiments indicate that in natural systems, neither PG nor 2-BE is expected to undergo significant, rapid degradation due to direct or indirect photolysis. PG and 2-BE are effectively degraded through indirect photolysis in the presence of high HO concentrations, suggesting UV/H2O2 is a feasible possibility for the treatment of waters containing PG and 2-BE. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. The effect of inlet conditions on lean premixed gas turbine combustor performance

    Science.gov (United States)

    Vilayanur, Suresh Ravi

    than uniformly mixed packets. This shedding of eddies leads to an acoustic emission that can be identified in a select frequency range. The CO production is related to the swirl strength due to the proportion of products entrained into the recirculation zone. Neither lean blowout nor combustion efficiency are affected by the inlet condition variation within the range studied.

  1. 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

  2. Aeolian responses to climate variability during the past century on Mesquite Lake Playa, Mojave Desert

    Science.gov (United States)

    Whitney, John W.; Breit, George N.; Buckingham, S.E.; Reynolds, Richard L.; Bogle, Rian C.; Luo, Lifeng; Goldstein, Harland L.; Vogel, John M.

    2015-01-01

    The erosion and deposition of sediments by wind from 1901 to 2013 have created large changes in surface features of Mesquite Lake playa in the Mojave Desert. The decadal scale recurrence of sand-sheet development, migration, and merging with older dunes appears related to decadal climatic changes of drought and wetness as recorded in the precipitation history of the Mojave Desert, complemented by modeled soil-moisture index values. Historical aerial photographs, repeat land photographs, and satellite images document the presence and northward migration of a mid-20th century sand sheet that formed during a severe regional drought that coincided with a multi-decadal cool phase of the Pacific Decadal Oscillation (PDO). The sand sheet slowly eroded during the wetter conditions of the subsequent PDO warm phase (1977–1998) due to a lack of added sediment. Sand cohesion gradually increased in the sand sheet by seasonal additions of salt and clay and by re-precipitation of gypsum, which resulted in the wind-carving of yardangs in the receding sand sheet. Smaller yardangs were aerodynamically shaped from coppice dunes with salt-clay crusts, and larger yardangs were carved along the walls and floor of trough blowouts. Evidence of a 19th century cycle of sand-sheet formation and erosion is indicated by remnants of yardangs, photographed in 1901 and 1916, that were found buried in the mid-20th century sand sheet. Three years of erosion measurements on the playa, yardangs, and sand sheets document relatively rapid wind erosion. The playa has lowered 20 to 40 cm since the mid-20th century and a shallow deflation basin has developed since 1999. Annually, 5–10 cm of surface sediment was removed from yardang flanks by a combination of wind abrasion, deflation, and mass movement. The most effective erosional processes are wind stripping of thin crusts that form on the yardang surfaces after rain events and the slumping of sediment blocks from yardang flanks. These wind

  3. Role of EPS, Dispersant and Nutrients on the Microbial Response and MOS Formation in the Subarctic Northeast Atlantic

    Directory of Open Access Journals (Sweden)

    Tony Gutierrez

    2017-04-01

    Full Text Available In this study we report the formation of marine oil snow (MOS, its associated microbial community, the factors influencing its formation, and the microbial response to crude oil in surface waters of the Faroe-Shetland Channel (FSC. The FSC is a subarctic region that is hydrodynamically complex located in the northeast Atlantic where oil extraction is currently occurring and where exploration is likely to expand into its deeper waters (>500 m. A major oil spill in this region may mirror the aftermath that ensued following the Deepwater Horizon (DWH blowout in the Gulf of Mexico, where the massive influx of Macondo crude oil triggered the formation of copious quantities of rapidly sinking MOS and successional blooms of opportunistic oil-degrading bacteria. In laboratory experiments, we simulated environmental conditions in sea surface waters of the FSC using water collected from this site during the winter of 2015. We demonstrated that the presence of dispersant triggers the formation of MOS, and that nutrient amendments magnify this. Illumina MiSeq sequencing revealed the enrichment on MOS of associated oil-degrading (Cycloclasticus, Thalassolituus, Marinobacter and EPS-producing (Halomonas, Pseudoalteromonas, Alteromonas bacteria, and included major representation by Psychrobacter and Cobetia with putative oil-degrading/EPS-producing qualities. The formation of marine snow, in the absence of crude oil and dispersant, in seawater amended with nutrients alone indicated that the de novo synthesis of bacterial EPS is a key factor in MOS formation, and the glycoprotein composition of the MOS aggregates confirmed that its amorphous biopolymeric matrix was of microbial (likely bacterial origin. The presence of dispersants and crude oil with/without nutrients resulted in distinct microbial responses marked by intermittent, and in some cases short-lived, blooms of opportunistic heterotrophs, principally obligate hydrocarbonoclastic (Alcanivorax

  4. Human and Organisational Safety Barriers in the Oil & Gas Industry

    International Nuclear Information System (INIS)

    Nystad, E.; Szőke, I.

    2016-01-01

    The oil & gas industry is a safety-critical industry where errors or accidents may potentially have severe consequences. Offshore oil & gas installations are complex technical systems constructed to pump hydrocarbons from below the seabed, process them and pipe them to onshore refineries. Hydrocarbon leaks may lead to major accidents or have negative environmental impacts. The industry must therefore have a strong focus on safety. Safety barriers are devices put into place to prevent or reduce the effects of unwanted incidents. Technical barriers are one type of safety barrier, e.g., blow-out preventers to prevent uncontrolled release of hydrocarbons from a well. Human operators may also have an important function in maintaining safety. These human operators are part of a larger organisation consisting of different roles and responsibilities and with different mechanisms for ensuring safety. This paper will present two research projects from the Norwegian oil & gas industry that look at the role of humans and organisations as safety barriers. The first project used questionnaire data to investigate the use of mindful safety practices (safety-promoting work practices intended to prevent or interrupt unwanted events) and what contextual factors may affect employees’ willingness to use these safety practices. Among the findings was that employees’ willingness to use mindful safety practices was affected more by factors on a group level than factors at an individual or organisational level, and that the factors may differ depending on what is the object of a practice—the employee or other persons. It was also suggested that employees’ willingness to use mindful safety practices could be an indicator used in the assessment of the safety level on oil & gas installations. The second project is related to organisational safety barriers against major accidents. This project was based on a review of recent incidents in the Norwegian oil & gas industry, as well as

  5. Correlating Distal, Medial and Proximal Ejecta Transport/Emplacement From Oblique Cosmic Impact On North American Continental Ice Sheet At MIS20 ( 786 ka) Via Suborbital Analysis (SA).

    Science.gov (United States)

    Harris, T. H. S.; Davais, M. E.

    2017-12-01

    Several elements of the 786 ka Australasian (AA) tektite imprint bear close scrutinyin order to locate the parent impact site or structure. The unique Carolina bays unit geologic formation is indicated as a large "medial" ejecta blanket from a large cosmic impact during a period containing 786 ka. Coincidence? Kg-scale sub-spherical hollow splash form AA tektites implies prolonged atmospheric blow out-scale momentum current with a core of sub-parallel or divergent flow volume having essentially zero turbulence. This would allow for plasma entrainment and heating of target mass at prolonged low dynamic pressure during outflow, where adiabatic expansion could deliver both semi-solid Muong Nong-type and inviscid melts above the atmosphere for gentle release upon rarefaction in vacuum. Within a large atmospheric blow-out scale momentum current, target mass becomes entrained at the speed of adiabatic outflow. 10+ km/s ejecta entrainment yields inter-hemispheric emplacement from launch per governing suborbital mechanics, without question. Oblique impact into a thick ice sheet explains reduced excavation volume and shearing disruption in the form of hypersonic steam plasma scouring. Adiabatic expansion would be immediately available to accelerate and further heat proto-tektite target mass. With shock no longer the sole transport engine, kg-scale splash forms and tektite speeds above the post-shock vaporization velocity of quartz are explained by expansion of shocked ice, in agreement with the observed imprint. The 6 Carolina bay shapes or "Davias Archetypes" are reproducible using conic perturbation in Suborbital Analysis, conforming to a formative mechanism of suborbital transport and ballistic emplacement: "Suborbital Obstruction Shadowing" needs only 3 parts in 10,000 of VEL variation around a circular EL-AZ-VEL launch cone, before considering re-entry effects. Transport energy of the Carolina bay sand, calculated using the 3.5 to 4 km/s launch VEL required for its

  6. 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

  7. Systems Design and Experimental Evaluation of a High-Altitude Relight Test Facility

    Science.gov (United States)

    Paxton, Brendan

    Novel advances in gas turbine engine combustor technology, led by endeavors into fuel efficiency and demanding environmental regulations, have been fraught with performance and safety concerns. While the majority of low emissions gas turbine engine combustor technology has been necessary for power generation applications, the push for ultra-low NOx combustion in aircraft jet engines has been ever present. Recent state-of-the-art combustor designs notably tackle historic emissions challenges by operating at fuel-lean conditions, which are characterized by an increase in the amount of air flow sent to the primary combustion zone. While beneficial in reducing NOx emissions, the fuel-lean mechanisms that characterize these combustor designs rely heavily upon high-energy and high-velocity air flows to sufficiently mix and atomize fuel droplets, ultimately leading to flame stability concerns during low-power operation. When operating at high-altitude conditions, these issues are further exacerbated by the presence of low ambient air pressures and temperatures, which can lead to engine flame-out situations and hamper engine relight attempts. To aid academic and industrial research ventures into improving the high-altitude lean blow-out and relight performance of modern gas turbine engine combustor technologies, the High-Altitude Relight Test Facility (HARTF) was designed and constructed at the University of Cincinnati (UC) Combustion and Fire Research Laboratory (CFRL). Following its construction, an experimental evaluation of its abilities to facilitate optically-accessible ignition, combustion, and spray testing for gas turbine engine combustor hardware at simulated high-altitude conditions was performed. In its evaluation, performance limit references were established through testing of the HARTF vacuum and cryogenic air-chilling capabilities. These tests were conducted with regard to end-user control---the creation and the maintenance of a realistic high

  8. Relativistic electron beams driven by single-cycle laser pulses at kHz repetition rate (Conference Presentation)

    Science.gov (United States)

    Faure, Jérôme; Guénot, Diego; Gustas, Dominykas; Vernier, Aline; Beaurepaire, Benoît; Böhle, Frederik; López-Martens, Rodrigo; Lifschitz, Agustin

    2017-05-01

    Laser-plasma accelerators are usually driven by 100-TW class laser systems with rather low repetition rates. However, recent years have seen the emergence of laser-plasma accelerators operating with kHz lasers and energies lower than 10 mJ. The high repetition-rate is particularly interesting for applications requiring high stability and high signal-to-noise ratio but lower energy electrons. For example, our group recently demonstrated that kHz laser-driven electron beams could be used to capture ultrafast structural dynamics in Silicon nano-membranes via electron diffraction with picosecond resolution. In these first experiments, electrons were injected in the density gradients located at the plasma exit, resulting in rather low energies in the 100 keV range. The electrons being nonrelativistic, the bunch duration quickly becomes picosecond long. Relativistic energies are required to mitigate space charge effects and maintain femtosecond bunches. In this paper, we will show very recent results where electrons are accelerated in laser-driven wakefields to relativistic energies, reaching up to 5 MeV at kHz repetition rate. The electron energy was increased by nearly two orders of magnitude by using single-cycle laser pulses of 3.5 fs, with only 2.5 mJ of energy. Using such short pulses of light allowed us to resonantly excite high amplitude and nonlinear plasma waves at high plasma density, ne=1.5-2×1020 cm-3, in a regime close to the blow-out regime. Electrons had a peaked distribution around 5 MeV, with a relative energy spread of 30 %. Charges in the 100's fC/shot and up to pC/shot where measured depending on plasma density. The electron beam was fairly collimated, 20 mrad divergence at Full Width Half Maximum. The results show remarkable stability of the beam parameters in terms of beam pointing and electron distribution. 3D PIC simulations reproduce the results very well and indicate that electrons are injected by the ionization of Nitrogen atoms, N5+ to N6

  9. Produced water disposal in the southern San Joaquin Basin: a direct analog for brine leakage in response to carbon storage

    Science.gov (United States)

    Jordan, P. D.; Gillespie, J.

    2013-12-01

    contaminated groundwater or for which there was such a concern, and discussed 85 different geographic locations. They described groundwater contamination at hundreds of wells during and previous to the publication period. Contamination due to upward leakage caused by produced water disposal injection was not mentioned. Previous research found The Bakersfield Californian covered more well blowouts with the highest public consequence (evacuation) than did reports from the relevant state agency, but had virtually no coverage of the least consequential blow outs. This suggests the lack of reporting of groundwater impacts from leakage due to produced water disposal injection indicates no significant public impact, such as closure of numerous public supply wells, occurred during the article time period or for some years previous. This research continues with analysis of historic groundwater constituent data available from the California State Water Resources Control Board's Geotracker Groundwater Ambient Monitoring & Assessment database. For instance this database contains TDS and other constituent results for 149 wells within or in the immediate vicinity of the Fruitvale oil field.

  10. DWH MC 252: Subsurface Oil Transport

    Science.gov (United States)

    Beegle-Krause, C. J.; Boyer, T.; Murray, D.

    2010-12-01

    Before reaching the ocean surface, the oil and gas released from the DWH MC 252 blowout at 1500 m moves as a buoyant plume until the trapping depth and plume transition point are reached (Zheng et al 2002). At the transition point, the oil droplets and bubbles move independently of each other, and rise at a rate related to their diameter. The oil density, droplet size distribution and currents primarily determine the distribution of the oil between: Large droplets that rise quickly and create a surface expression of the oil. Moderate size droplets that rise over the course of days, and so spread out quite differently than the surface oil, and commonly do not reach the surface in large enough quantities to create a surface sheen. These droplets separate in the currents, particularly in the strong current shear in upper 500 m currents. Very tiny droplets that rise very slowly, over the course or weeks to months, and may be removed by dissolution, biodegradation or marine snow before ever reaching the surface. Modeling and observations (Joint Analysis Group, 2010) confirm the presence of a deep layer of oil and gas between approximately 1100 and 1300 m over the release location and spreading out along the isopycnal surfaces. Later in the event, a small oxygen depression was a proxy for where oil and gas had been. The DWH MC252 well is located at intermediate depth in the Gulf of Mexico (GoM). The water mass is Antarctic Intermediate Water, which enters and exits the GoM through the Yucatan Straits. Surface influences, such as Loop Current Frontal Eddies (e.g. Berger et al 2000) can reach down to these depths, and alter the flow within De Soto Canyon. The water mass containing the deep layer of oil droplets changes depth within the GoM, but does not reach above a depth of about 900 m. There are no physical processes that could cause this deep layer of oil to reach the continental shelf or the Florida Straits. Observed and historical hydrographic data, observations

  11. FINESSE: Field Investigations to Enable Solar System Science and Exploration

    Science.gov (United States)

    Heldmann, Jennifer; Lim, Darlene; Colaprete, Anthony

    2015-01-01

    The FINESSE (Field Investigations to Enable Solar System Science and Exploration) team is focused on a science and exploration field-based research program aimed at generating strategic knowledge in preparation for the human and robotic exploration of the Moon, near-Earth asteroids (NEAs) and Phobos and Deimos. We follow the philosophy that "science enables exploration and exploration enables science." 1) FINESSE Science: Understand the effects of volcanism and impacts as dominant planetary processes on the Moon, NEAs, and Phobos & Deimos. 2) FINESSE Exploration: Understand which exploration concepts of operations (ConOps) and capabilities enable and enhance scientific return. To accomplish these objectives, we are conducting an integrated research program focused on scientifically-driven field exploration at Craters of the Moon National Monument and Preserve in Idaho and at the West Clearwater Lake Impact Structure in northern Canada. Field deployments aimed at reconnaissance geology and data acquisition were conducted in 2014 at Craters of the Moon National Monument and Preserve. Targets for data acquisition included selected sites at Kings Bowl eruptive fissure, lava field and blowout crater, Inferno Chasm vent and outflow channel, North Crater lava flow and Highway lava flow. Field investigation included (1) differential GPS (dGPS) measurements of lava flows, channels (and ejecta block at Kings Bowl); (2) LiDAR imaging of lava flow margins, surfaces and other selected features; (3) digital photographic documentation; (4) sampling for geochemical and petrographic analysis; (5) UAV aerial imagery of Kings Bowl and Inferno Chasm features; and (6) geologic assessment of targets and potential new targets. Over the course of the 5-week field FINESSE campaign to the West Clearwater Impact Structure (WCIS) in 2014, the team focused on several WCIS research topics, including impactites, central uplift formation, the impact-generated hydrothermal system, multichronometer

  12. Self-potential monitoring of a crude oil contaminated site (Trecate, Italy): first results of the modelling.

    Science.gov (United States)

    Giampaolo, V.; Rizzo, E.; Titov, K.; Maineult, A.; Lapenna, V.

    2012-04-01

    The contamination of soils and groundwater by hydrocarbon, due to blow out, leakage from tank or pipe and oil spill, is a heavy environmental problem because infiltrated oil can persist in the ground for a long time. The existing methods used for the remediation of these contaminated sites are invasive, time consuming and expensive. Therefore, in the last years, there was a growing interest in the use of geophysical methods for environmental monitoring (Atekwana et al., 2000; Chambers et al., 2004; Song et al., 2005; French et al., 2009). A particular attention is given to the self-potential (SP) method because SP is sensitive to the contaminant chemistry and redox processes generated by bacteria during the biodegradation (Atekwana et al., 2004; Naudet and Revil, 2005; Revil et al., 2010). Here we show the results of SP investigations carried out at Trecate site (Italy). This site was affected by a crude oil contamination from a well blowout in 1994. Four SP surveys (October 2009, March 2010, October 2010, and March 2011) were conducted at the site, both in the contaminated and uncontaminated regions. Significant changes are observed between SP data collected at different times. In particular, we found mostly negative electrical potential in October surveys and positive electrical potential in March surveys. The SP distributions can be interpreted as the superposition of many components, including a horizontal water-flow in the saturated shallow aquifer toward South-East, the infiltration movement of water in the unsaturated zone and, possibly, the oxidation-reduction phenomena due to bacterial activity. As the groundwater flow usually produces SP linear trends, the data were detrended by linear regression, taking into account the measured piezometric heads in the aquifer. The detrended SP data show that the SP distribution within the contaminated zone is generally bipolar in October: the southern part of the contaminated area is characterized by negative values

  13. The HIP 79977 debris disk in polarized light

    Science.gov (United States)

    Engler, N.; Schmid, H. M.; Thalmann, Ch.; Boccaletti, A.; Bazzon, A.; Baruffolo, A.; Beuzit, J. L.; Claudi, R.; Costille, A.; Desidera, S.; Dohlen, K.; Dominik, C.; Feldt, M.; Fusco, T.; Ginski, C.; Gisler, D.; Girard, J. H.; Gratton, R.; Henning, T.; Hubin, N.; Janson, M.; Kasper, M.; Kral, Q.; Langlois, M.; Lagadec, E.; Ménard, F.; Meyer, M. R.; Milli, J.; Mouillet, D.; Olofsson, J.; Pavlov, A.; Pragt, J.; Puget, P.; Quanz, S. P.; Roelfsema, R.; Salasnich, B.; Siebenmorgen, R.; Sissa, E.; Suarez, M.; Szulagyi, J.; Turatto, M.; Udry, S.; Wildi, F.

    2017-11-01

    Context. Debris disks are observed around 10 to 20% of FGK main-sequence stars as infrared excess emission. They are important signposts for the presence of colliding planetesimals and therefore provide important information about the evolution of planetary systems. Direct imaging of such disks reveals their geometric structure and constrains their dust-particle properties. Aims: We present observations of the known edge-on debris disk around HIP 79977 (HD 146897) taken with the ZIMPOL differential polarimeter of the SPHERE instrument. We measure the observed polarization signal and investigate the diagnostic potential of such data with model simulations. Methods: SPHERE-ZIMPOL polarimetric data of the 15 Myr-old F star HIP 79977 (Upper Sco, 123 pc) were taken in the Very Broad Band (VBB) filter (λc = 735 nm, Δλ = 290 nm) with a spatial resolution of about 25 mas. Imaging polarimetry efficiently suppresses the residual speckle noise from the AO system and provides a differential signal with relatively small systematic measuring uncertainties. We measure the polarization flux along and perpendicular to the disk spine of the highly inclined disk for projected separations between 0.2'' (25 AU) and 1.6'' (200 AU). We perform model calculations for the polarized flux of an optically thin debris disk which are used to determine or constrain the disk parameters of HIP 79977. Results: We measure a polarized flux contrast ratio for the disk of (Fpol)disk/F∗ = (5.5 ± 0.9) × 10-4 in the VBB filter. The surface brightness of the polarized flux reaches a maximum of SBmax = 16.2 mag arcsec-2 at a separation of 0.2''-0.5'' along the disk spine with a maximum surface brightness contrast of 7.64 mag arcsec-2. The polarized flux has a minimum near the star 1''. This can be explained by a radial blow-out of small grains. The data are modelled as a circular dust belt with a well defined disk inclination I = 85( ± 1.5)° and a radius between r0 = 60 and 90 AU. The radial

  14. Human impacts on the evolution of Rosolina Mare (Northern Adriatic, Italy): first results

    Science.gov (United States)

    Corbau, Corinne; Simeoni, Umberto

    2013-04-01

    The Italian coasts have undergone profound changes over the last century, in particular after the late 1950's. With the tourism industry development, the coastal system has been hardened resulting in the drastic reduction of its evolutive capacity. Human activity has therefore become a geological agent that has affected the evolution of the coastal zone both directly and indirectly in the last century. This study focuses on some of the coastal morphologies that have been modified by human actions in long and medium-term. The research was based on a comparison of sixty-year changes in land use, on dune-beach system and on the nearshore of Rosolina (Northern Adriatic, Italy). This coastal sandy zone extends over about 8 km in a N-NE - S-SW direction, and is delimited by the Adige River to the north and by the Porto Caleri to the south. This littoral, characterized by highly humanized stretches and natural stretches without human activities, can be divided into three parts: the first in the north, about 2 km long, where the beach is almost non-existent, the second in the central part long about 3 km, with a wide beach and completely built up for tourism, and the third in the south, about 3 km long, is within a natural park and is characterized by a wide beach bordered by a complex dune system. In the central part the coastal dunes present the greater heights, with an average of about +7 m (+ 4.5 m to +11 m); in the northern part the rare dunes reach heights of about +5 m (+4.5 m to +5.5 m). In the southern part the dunes present lower heights averaging +4.2 m (from +3 m to +5.5 m). The conservation state of the dunes is the result of coastal anthropization: blowouts and breaches in the coastal dune system are observed where there was the greatest urban development to allow users access to the beach. These "passages", however, constitute preferential sediment paths out of the beach as sediments are no longer stopped by the dune and its vegetation and are thus

  15. Environmental risks of the gas hydrate field development in the Eastern Nankai Trough

    Science.gov (United States)

    Yamamoto, K.; Nagakubo, S.

    2009-12-01

    To establish any kinds of new energy resources, environmental impacts of the technology should be well understood before full industrial implementation. Methane hydrate (MH), a relatively clean fossil energy with low CO2 and no SOx emission, is not an exception. Because methane gas itself has strong greenhouse gas effect, and methane hydrate is not stable under the atmospheric pressure and room temperature, public image of MH field development is very risky game and potentially disastrous to the global climate. However, the real physics of the MH bearing sediments is far different from such images. MH21 Research Consortium in Japan has studied about the resource assessment and production techniques to develop MH since 2001. As the results, we found several gas hydrate concentrated zones with pore filling type hydrate in sandy layers of turbidite sediment in the Eastern Nankai Trough area off coasts of the Central Japan. The depressurization technique, in the other word, in-situ MH dissociation by water production and natural heat supply from surrounding formation, will be used as the basic method to produce methane gas from MH. Under the conditions, we have evaluated realistic environmental risk of the MH production. Because the most MH found in the Eastern Nankai Trough are composed of biogenic and almost pure methane, there is no concern of sea water contamination by oil releases that is the most common environmental disaster caused by misconducts of the oil industry. Also MH reservoirs there are not pressurized, and blowout of wells during drilling is very unlikely. Endothermic MH dissociation process decreases formation temperature with depressurization, and give negative feedback, then, there is no chance of chain reaction. Heat supply from surrounding formations is necessary for continuous dissociation, but heat transfer in the formations is relatively slow, and the dissociation rate is limited. Once the operation to pump water in boreholes for

  16. BP « Deepwater Horizon » du Golfe du Mexique à l’Afrique : un tournant pour l’industrie pétrolière ? BP “Deepwater Horizon” from the Gulf of Mexico to Africa : a turning point for the Oil Industry ?

    Directory of Open Access Journals (Sweden)

    Géraud Magrin

    2010-09-01

    Full Text Available L’explosion de la plateforme BP Deepwater Horizon du 20 avril 2010 constitue une des plus graves pollutions pétrolières de l’histoire. Sa localisation dans les eaux du premier consommateur mondial, et l’implication d’une des compagnies les plus avancées en matière de responsabilité sociale d’entreprise, sont révélatrices des enjeux actuels de la gestion environnementale des risques pétroliers. Alors que les gisements les plus accessibles sont exploités par des sociétés nationales, les compagnies internationales satisfont l’inextinguible demande en pétrole du système mondial en explorant des situations extrêmes, comme les eaux très profondes. Cela s’accompagne de risques croissants. La catastrophe de BP nous montre le danger de considérer un risque infime comme une absence de risque : l’exemption de planification d’urgence explique la longue durée et l’ampleur de la fuite. Elle rappelle aussi que les impacts du pétrole ne sont bien connus qu’à la surface et le long des côtes : or, cette fuite en eaux profondes causera des dommages écologiques graves dans les zones pélagiques. Cet événement changera les règles du jeu de la régulation environnementale pétrolière dans les zones sensibles. Nous donnons un aperçu des évolutions qu’il pourrait favoriser en Afrique, notamment en Mauritanie. Il reste à savoir si l’augmentation des coûts qui en résultera contribuera à accélérer la transition énergétique mondiale hors de la dépendance des hydrocarbures.On Thursday the 20th april 2010, the blowout of the Deepwater Horizon drilling platform operated by BP in the Gulf of Mexico starts what can be considered one of the major oil spills in the world history. Taking place in the national waters of the world’s first oil consumer and affecting one of the more advanced oil major in Corporate Social Responsibility, this accident may turn out to be a land mark for environmental management in the

  17. RPAS Monitoring of the Morphological Evolution of Coastal Foredunes

    Science.gov (United States)

    Taddia, Yuri; Corbau, Corinne; Elena, Zambello; Russo, Valentina; Pellegrinelli, Alberto; Simeoni, Umberto

    2016-04-01

    beach (about 1.50 meter amsl), isolated embryo dunes (incipient foredunes) and foredunes develop along a cross-shore section of about 30 meters; • a "depresssive" interdune of about 10 meters; • a second field of successive well-developed dunes. The first foredunes are of small dimensions (about 0.50 m height), and are aligned to the prevailing wind directions. The second field of dunes are higher (about 1 meter height) and form a "continuous" dune ridge parallel to the shoreline. Another significant advantage of this method is the possibility to obtain information on the vegetation, which is an important factor driving the evolution of coastal dunes. Different blowouts and pathways have been also mapped. The use of the orthophoto will therefore allow to collect simultaneously physical and biological data and consequently to analyze their interaction in order to improve the management of the coastal dune systems. This study exhibits how RPAS can be successfully used in representing the spatial distribution of embryo coastal dunes and in monitoring their development.

  18. A Risk Analysis Methodology to Address Human and Organizational Factors in Offshore Drilling Safety: With an Emphasis on Negative Pressure Test

    Science.gov (United States)

    Tabibzadeh, Maryam

    According to the final Presidential National Commission report on the BP Deepwater Horizon (DWH) blowout, there is need to "integrate more sophisticated risk assessment and risk management practices" in the oil industry. Reviewing the literature of the offshore drilling industry indicates that most of the developed risk analysis methodologies do not fully and more importantly, systematically address the contribution of Human and Organizational Factors (HOFs) in accident causation. This is while results of a comprehensive study, from 1988 to 2005, of more than 600 well-documented major failures in offshore structures show that approximately 80% of those failures were due to HOFs. In addition, lack of safety culture, as an issue related to HOFs, have been identified as a common contributing cause of many accidents in this industry. This dissertation introduces an integrated risk analysis methodology to systematically assess the critical role of human and organizational factors in offshore drilling safety. The proposed methodology in this research focuses on a specific procedure called Negative Pressure Test (NPT), as the primary method to ascertain well integrity during offshore drilling, and analyzes the contributing causes of misinterpreting such a critical test. In addition, the case study of the BP Deepwater Horizon accident and their conducted NPT is discussed. The risk analysis methodology in this dissertation consists of three different approaches and their integration constitutes the big picture of my whole methodology. The first approach is the comparative analysis of a "standard" NPT, which is proposed by the author, with the test conducted by the DWH crew. This analysis contributes to identifying the involved discrepancies between the two test procedures. The second approach is a conceptual risk assessment framework to analyze the causal factors of the identified mismatches in the previous step, as the main contributors of negative pressure test

  19. Impact of coastal management practice on long-term foredune behaviour

    Science.gov (United States)

    Wijnberg, Kathelijne M.; Bochev-van der Burgh, Lisette M.

    2010-05-01

    -active. Prior to 1990, when storm erosion occurred or blowouts developed in the foredune, recovery of the dune was stimulated by placing sand fences and planting marram grass. In case of dune erosion, the steep erosion front was usually flattened for public safety by ground moving equipment . After 1990, large-scale sand nourishment programs were implemented (beach and nearshore) in order to build erosion buffers, and over time the earlier dune management measures were to a large extent abandoned. Our study shows that in the reactive approach man only interferes with high order processes that do not fundamentally change the currently present type of foredune, hence will not fundamentally change the morphodynamic functioning of the current foredune system. In the pro-active approach, to the contrary, man interferes at a much more fundamental level by changing the sediment budget of the beach-dune system. Indications appear from the morphological analysis that this approach may lead to changes in the prevailing type of foredune morphology. In that case, the future characteristic foredune morphology and behaviour may deviate considerably from what we see today along this coastline.

  20. Hyperfractionated stereotactic reirradiation for recurrent head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Cvek, Jakub; Knybel, Lukas; Skacelikova, Eva; Otahal, Bretislav; Molenda, Lukas; Feltl, David [University Hospital Ostrava, Department of Oncology, Ostrava (Czech Republic); Stransky, Jiri; Res, Oldrich [University Hospital Ostrava, Department of Maxilofacial Surgery, Ostrava (Czech Republic); Matousek, Petr; Zelenik, Karol [University Hospital Ostrava, Department of Otolaryngology, Ostrava (Czech Republic)

    2016-01-15

    The goal of this work was to evaluate the efficacy and toxicity of hyperfractionated stereotactic reirradiation (re-RT) as a treatment for inoperable, recurrent, or second primary head and neck squamous cell cancer (HNSCC) that is not suitable for systemic treatment. Forty patients with recurrent or second primary HNSCC were included in this study. The patients had a median gross tumor volume of 76 ml (range 14-193 ml) and a previous radiotherapy dose greater than 60 Gy. Treatment was designed to cover 95 % of the planning target volume (PTV, defined as gross tumor volume [GTV] + 3 mm to account for microscopic spreading, with no additional set-up margin) with the prescribed dose (48 Gy in 16 fractions b.i.d.). Treatment was administered twice daily with a minimum 6 h gap. Uninvolved lymph nodes were not irradiated. Treatment was completed as planned for all patients (with median duration of 11 days, range 9-14 days). Acute toxicity was evaluated using the RTOG/EORTC scale. A 37 % incidence of grade 3 mucositis was observed, with recovery time of ≤ 4 weeks for all of these patients. Acute skin toxicity was never observed to be higher than grade 2. Late toxicity was also evaluated according to the RTOG/EORTC scale. Mandible radionecrosis was seen in 4 cases (10 %); however, neither carotid blowout syndrome nor other grade 4 late toxicity occurred. One-year overall survival (OS) and local progression-free survival (L-PFS) were found to be 33 and 44 %, respectively. Performance status and GTV proved to be significant prognostic factors regarding local control and survival. Hyperfractionated stereotactic re-RT is a reasonable treatment option for patients with recurrent/second primary HNSCC who were previously exposed to high-dose irradiation and who are not candidates for systemic treatment or hypofractionation. (orig.) [German] Ziel der Studie war es, die Effektivitaet und Toxizitaet der hyperfraktionierten akzelerierten stereotaktischen Wiederbestrahlung (re

  1. Landscape paintings of the 17th and 19th century as a tool for coastal zone management

    Science.gov (United States)

    Jungerius, P. D.; van den Ancker, J.

    2012-04-01

    without harbours, the level beaches induced the development of the flat-bottomed Dutch fishing vessels, a practice surviving in Denmark. • Over time, the morphology of the foredunes changed considerably. In the early 16th century foredunes appear to have been absent. Public access to the foredune which was allowed in the 19th century maintained the vitality of the sand-catching marram grass. Management measures changed the foredune in a barbed wire protected sand-dike with planted marram grass in the course of the 20th century. • Already 17th century paintings show blowouts in stabilized parabolic dunes. Present-day ecologists re-activate these dunes presuming they were stabilized by man as late as the beginning of the 20th century. • Disappeared landscapes include beach ridges levelled to provide sand for building purposes and to obtain land for the bulb-growing industry.

  2. Developing a Comprehensive Risk Assessment Framework for Geological Storage CO2

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, Ian [Univ. of Texas, Austin, TX (United States)

    2014-08-31

    The operational risks for CCS projects include: risks of capturing, compressing, transporting and injecting CO₂; risks of well blowouts; risk that CO2 will leak into shallow aquifers and contaminate potable water; and risk that sequestered CO2 will leak into the atmosphere. This report examines these risks by using information on the risks associated with analogue activities such as CO2 based enhanced oil recovery (CO2-EOR), natural gas storage and acid gas disposal. We have developed a new analysis of pipeline risk based on Bayesian statistical analysis. Bayesian theory probabilities may describe states of partial knowledge, even perhaps those related to non-repeatable events. The Bayesian approach enables both utilizing existing data and at the same time having the capability to adsorb new information thus to lower uncertainty in our understanding of complex systems. Incident rates for both natural gas and CO2 pipelines have been widely used in papers and reports on risk of CO2 pipelines as proxies for the individual risk created by such pipelines. Published risk studies of CO2 pipelines suggest that the individual risk associated with CO2 pipelines is between 10-3 and 10-4, which reflects risk levels approaching those of mountain climbing, which many would find unacceptably high. This report concludes, based on a careful analysis of natural gas pipeline failures, suggests that the individual risk of CO2 pipelines is likely in the range of 10-6 to 10-7, a risk range considered in the acceptable to negligible range in most countries. If, as is commonly thought, pipelines represent the highest risk component of CCS outside of the capture plant, then this conclusion suggests that most (if not all) previous quantitative- risk assessments of components of CCS may be orders of magnitude to high. The potential lethality of unexpected CO2 releases

  3. Deepwater Horizon Accident Investigation Report

    International Nuclear Information System (INIS)

    2010-09-01

    On the evening of April 20, 2010, a well control event allowed hydrocarbons to escape from the Macondo well onto Transocean's Deepwater Horizon, resulting in explosions and fire on the rig. Eleven people lost their lives, and 17 others were injured. The fire, which was fed by hydrocarbons from the well, continued for 36 hours until the rig sank. Hydrocarbons continued to flow from the reservoir through the wellbore and the blowout preventer (BOP) for 87 days, causing a spill of national significance. BP Exploration and Production Inc. was the lease operator of Mississippi Canyon Block 252, which contains the Macondo well. BP formed an investigation team that was charged with gathering the facts surrounding the accident, analyzing available information to identify possible causes and making recommendations to enable prevention of similar accidents in the future. The BP investigation team began its work immediately in the aftermath of the accident, working independently from other BP spill response activities and organizations. The ability to gather information was limited by a scarcity of physical evidence and restricted access to potentially relevant witnesses. The team had access to partial real-time data from the rig, documents from various aspects of the Macondo well's development and construction, witness interviews and testimony from public hearings. The team used the information that was made available by other companies, including Transocean, Halliburton and Cameron. Over the course of the investigation, the team involved over 50 internal and external specialists from a variety of fields: safety, operations, subsea, drilling, well control, cementing, well flow dynamic modeling, BOP systems and process hazard analysis. This report presents an analysis of the events leading up to the accident, eight key findings related to the causal chain of events and recommendations to enable the prevention of a similar accident. The investigation team worked separately

  4. A Study of Pollutant Formation from the Lean Premixed Combustion of Gaseous Fuel Alternatives to Natural Gas

    Science.gov (United States)

    Fackler, Keith Boyd, Jr.

    The goal of this research is to identify how nitrogen oxide (NO x) emissions and flame stability (blowout) are impacted by the use of fuels that are alternatives to typical pipeline natural gas. The research focuses on lean, premixed combustors that are typically used in state-of-the-art natural gas fueled systems. An idealized laboratory lean premixed combustor, specifically the jet-stirred reactor, is used for experimental data. A series of models, including those featuring detailed fluid dynamics and those focusing on detailed chemistry, are used to interpret the data and understand the underlying chemical kinetic reasons for differences in emissions between the various fuel blends. An ultimate goal is to use these data and interpretive tools to develop a way to predict the emission and stability impacts of changing fuels within practical combustors. All experimental results are obtained from a high intensity, single-jet stirred reactor (JSR). Five fuel categories are studied: (1) pure H 2, (2) process and refinery gas, including combinations of H2, CH4, C2H6, and C3H8, (3) oxygen blown gasified coal/petcoke composed of H2, CO, and CO2, (4) landfill and digester gas composed of CH4, CO2, and N2, and (5) liquified natural gas (LNG)/shale/associated gases composed of CH4, C2H6, and C3 H8. NOx measurements are taken at a nominal combustion temperature of 1800 K, atmospheric pressure, and a reactor residence time of 3 ms. This is done to focus the results on differences caused by fuel chemistry by comparing all fuels at a common temperature, pressure, and residence time. This is one of the few studies in the literature that attempts to remove these effects when studying fuels varying in composition. Additionally, the effects of changing temperature and residence time are investigated for selected fuels. At the nominal temperature and residence time, the experimental and modeling results show the following trends for NOx emissions as a function of fuel type: 1.) NOx

  5. Editorial: Focus on Laser- and Beam-Driven Plasma Accelerators

    Science.gov (United States)

    Joshi, Chan; Malka, Victor

    2010-04-01

    The ability of short but intense laser pulses to generate high-energy electrons and ions from gaseous and solid targets has been well known since the early days of the laser fusion program. However, during the past decade there has been an explosion of experimental and theoretical activity in this area of laser-matter interaction, driven by the prospect of realizing table-top plasma accelerators for research, medical and industrial uses, and also relatively small and inexpensive plasma accelerators for high-energy physics at the frontier of particle physics. In this focus issue on laser- and beam-driven plasma accelerators, the latest advances in this field are described. Focus on Laser- and Beam-Driven Plasma Accelerators Contents Slow wave plasma structures for direct electron acceleration B D Layer, J P Palastro, A G York, T M Antonsen and H M Milchberg Cold injection for electron wakefield acceleration X Davoine, A Beck, A Lifschitz, V Malka and E Lefebvre Enhanced proton flux in the MeV range by defocused laser irradiation J S Green, D C Carroll, C Brenner, B Dromey, P S Foster, S Kar, Y T Li, K Markey, P McKenna, D Neely, A P L Robinson, M J V Streeter, M Tolley, C-G Wahlström, M H Xu and M Zepf Dose-dependent biological damage of tumour cells by laser-accelerated proton beams S D Kraft, C Richter, K Zeil, M Baumann, E Beyreuther, S Bock, M Bussmann, T E Cowan, Y Dammene, W Enghardt, U Helbig, L Karsch, T Kluge, L Laschinsky, E Lessmann, J Metzkes, D Naumburger, R Sauerbrey, M. Scḧrer, M Sobiella, J Woithe, U Schramm and J Pawelke The optimum plasma density for plasma wakefield excitation in the blowout regime W Lu, W An, M Zhou, C Joshi, C Huang and W B Mori Plasma wakefield acceleration experiments at FACET M J Hogan, T O Raubenheimer, A Seryi, P Muggli, T Katsouleas, C Huang, W Lu, W An, K A Marsh, W B Mori, C E Clayton and C Joshi Electron trapping and acceleration on a downward density ramp: a two-stage ap