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Sample records for prudhoe bay oilfield

  1. Abundance and movements of caribou in the oilfield complex near Prudhoe Bay, Alaska

    Directory of Open Access Journals (Sweden)

    R.D. Cameron

    1995-12-01

    Full Text Available We examined the distribution and movements of 141 radiocollared female caribou (Rangifer tarandus granti of the Central Arctic Herd during summer, 1980-1993. Numbers of caribou locations within each of 5 quadrats along the arctic coast were totalled separately for days during which insects were active and inactive, and numbers of east-west and west-east crossings of each quadrat mid-line were determined from sequential observations. Both abundance and lateral movements of radiocollared females in the quadrat encompassing the intensively-developed Prudhoe Bay oilfield complex were significantly lower than in other quadrats (P < 0.001 and P < 0.00001, respectively. Avoidance of, and fewer movements within, the complex by female caribou are ostensibly in response to the dense network of production and support facilities, roads, above-ground pipelines, and the associated vehicular and human activity. Impaired access to this area constitutes a functional loss of habitat.

  2. Cumulative effects of climate change and ice-wedge degradation, Prudhoe Bay oilfield Alaska

    Science.gov (United States)

    Walker, D. A.; Kanevskiy, M. Z.; Shur, Y.; Raynolds, M. K.; Buchhorn, M.

    2016-12-01

    Development of Arctic oil & gas resources requires extensive networks of roads, pipelines and other forms of infrastructure. The Prudhoe Bay Oilfield is the largest Arctic oilfield in North America with a long, well-documented history. In a previous publication we analyzed the historical record of high-resolution aerial photos to document the long-term changes to infrastructure extent (1949-2010) for the entire oilfield, and an integrated-geoecological-historical-change-mapping (IGHCM) approach to document terrain changes within 22-km2 areas of the oilfield. We reported the recent widespread expansion of thermokarst, starting in about 1989. Here we examine the annual air-photo record to better pinpoint the years of major change. We also conducted detailed field studies of roadside changes using topographic surveys and soil, vegetation and ice-wedge coring studies. Both sites exhibit extensive ice-wedge degradation that is caused by a combination of a long-term warming trend a series of exceptionally warm summers, and infrastructure-related factors that melted the tops of ice wedges. Near-road thermokarst is enhanced by warmer soils associated with road dust, roadside flooding, near-road pipelines, communication cables, and altered snow regimes. These strongly affect roadside ecosystems and the infrastructure itself. Changes to ecosystems include altered hydrology with the drying of polygon centers and the formation of well-developed high-centered polygons occurs in some areas. Other areas develop extensive flooding and erosion of ice-wedge troughs. An unexpected result of flooding is the stabilization of ice-wedge degradation in some areas because the increased productivity of sedges in the flooded areas is producing large amounts of organic material that protects the tops of ice wedges from further degradation. The large increases in productivity in roadside areas also attract large flocks of waterfowl. Changes to the soils with the addition of thick layers of

  3. Pre-ABoVE: Geobotanical and Impact Map Collection for Prudhoe Bay Oilfield, Alaska

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides a collection of maps of geoecological characteristics of areas within the Beechey Point quadrangle near Prudhoe Bay on the North slope of...

  4. Cumulative geoecological effects of 62 years of infrastructure and climate change in ice-rich permafrost landscapes, Prudhoe Bay Oilfield, Alaska.

    Science.gov (United States)

    Raynolds, Martha K; Walker, Donald A; Ambrosius, Kenneth J; Brown, Jerry; Everett, Kaye R; Kanevskiy, Mikhail; Kofinas, Gary P; Romanovsky, Vladimir E; Shur, Yuri; Webber, Patrick J

    2014-04-01

    Many areas of the Arctic are simultaneously affected by rapid climate change and rapid industrial development. These areas are likely to increase in number and size as sea ice melts and abundant Arctic natural resources become more accessible. Documenting the changes that have already occurred is essential to inform management approaches to minimize the impacts of future activities. Here, we determine the cumulative geoecological effects of 62 years (1949-2011) of infrastructure- and climate-related changes in the Prudhoe Bay Oilfield, the oldest and most extensive industrial complex in the Arctic, and an area with extensive ice-rich permafrost that is extraordinarily sensitive to climate change. We demonstrate that thermokarst has recently affected broad areas of the entire region, and that a sudden increase in the area affected began shortly after 1990 corresponding to a rapid rise in regional summer air temperatures and related permafrost temperatures. We also present a conceptual model that describes how infrastructure-related factors, including road dust and roadside flooding are contributing to more extensive thermokarst in areas adjacent to roads and gravel pads. We mapped the historical infrastructure changes for the Alaska North Slope oilfields for 10 dates from the initial oil discovery in 1968-2011. By 2010, over 34% of the intensively mapped area was affected by oil development. In addition, between 1990 and 2001, coincident with strong atmospheric warming during the 1990s, 19% of the remaining natural landscapes (excluding areas covered by infrastructure, lakes and river floodplains) exhibited expansion of thermokarst features resulting in more abundant small ponds, greater microrelief, more active lakeshore erosion and increased landscape and habitat heterogeneity. This transition to a new geoecological regime will have impacts to wildlife habitat, local residents and industry. © 2013 John Wiley & Sons Ltd.

  5. Arctic cisco stable isotope data, Prudhoe Bay, August 2009

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set documents the carbon and nitrogen stable isotope ratios of age-0 Arctic cisco (Coregonus autumnalis) captured in Prudhoe Bay, Alaska in August 2009....

  6. Chemical Characterization of Atmospheric Particulate Matter from Prudhoe Bay, Alaska

    Science.gov (United States)

    Gunsch, M.; Kirpes, R.; Moffett, C. E.; Sheesley, R. J.; Pratt, K.

    2016-12-01

    Climate change is impacting the Arctic, leading to increasing temperatures and decreasing summer sea ice coverage which has allowed for increased oil and gas extraction activities. Prudhoe Bay is currently the second highest source of particulate matter from oil and gas extraction in the Arctic, and 3rd largest oil field in the United States. With drilling operations expected to increase due to the reduced sea ice coverage, these emissions, specifically contributions from black carbon and organic carbon, are expected to continue to increase over the coming decades. Given the complexity and evolving nature of atmospheric particles, as well as the logistical challenges associated with Arctic measurements, many uncertainties remain in our understanding of the impacts of increasing emissions in the Arctic. To investigate the size and chemistry of individual particles emitted from activities within the Prudhoe Bay oil fields in real-time, an aerosol time-of-flight mass spectrometer (ATOFMS) was deployed 300 km northwest of Prudhoe Bay to Barrow, AK during August-September 2015 as well as inside the Prudhoe Bay oil fields at Oliktok Point, AK during August-September 2016. During the 2015 measurements, particle number concentrations increased 10 times when under the influence of Prudhoe Bay, primarily from sub-50 nm particles attributed to transported combustion emissions. ATOFMS also identified increased number fractions of soot and organic carbon-sulfate particles (0.2 - 1.5 μm in diameter) when comparing Prudhoe Bay influential periods to Arctic Ocean influential periods. During 2016 measurements, parallel size-resolved number concentration measurements allowed for near-source quantification of number and mass concentrations of particles from the various sources of combustion within the oil fields, including residual fuel, diesel fuel and biomass burning. These measurements represent the first single particle chemical characterization of oil and gas extraction

  7. Summer bird use of a barrier island near Prudhoe Bay, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The number and distribution of birds near a barrier island west of Prudhoe Bay, Alaska, were recorded during the summer of 1972. Eiders fed and rested in the open...

  8. Thermal regime of permafrost at Prudhoe Bay, Alaska

    Science.gov (United States)

    Lachenbruch, A.H.; Sass, J.H.; Marshall, B.V.; Moses, T.H.

    1982-01-01

    Temperature measurements through permafrost in the oil field at Prudhoe Bay, Alaska, combined with laboratory measurements of the thermal conductivity of drill cuttings permit an evaluation of in situ thermal properties and an understanding of the general factors that control the geothermal regime. A sharp contrast in temperature gradient at ~600 m represents a contrast in thermal conductivity caused by the downward change from interstitial ice to interstitial water at the base of permafrost under near steady-state conditions. Interpretation of the gradient contrast in terms of a simple model for the conductivity of an aggregate yields the mean ice content and thermal conductivities for the frozen and thawed sections (8.1 and 4.7 mcal/cm sec ?C, respectively). These results yield a heat flow of ~1.3 HFU which is similar to other values on the Alaskan Arctic Coast; the anomalously deep permafrost is a result of the anomalously high conductivity of the siliceous ice-rich sediments. Curvature in the upper 160 m of the temperature profiles represents a warming of ~1.8?C of the mean surface temperature, and a net accumulation of 5-6 kcal/cm 2 by the solid earth surface during the last 100 years or so. Rising sea level and thawing sea cliffs probably caused the shoreline to advance tens of kilometers in the last 20,000 years, inundating a portion of the continental shelf that is presently the target of intensive oil exploration. A simple conduction model suggests that this recently inundated region is underlain by near-melting ice-rich permafrost to depths of 300-500 m; its presence is important to seismic interpretations in oil exploration and to engineering considerations in oil production. With confirmation of the permafrost configuration by offshore drilling, heat-conduction models can yield reliable new information on the chronology of arctic shorelines.

  9. Reservoir description of Endicott Field, Prudhoe Bay, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Behrman, P.G.; Woidneck, R.K.; Soule, C.H.; Wu, J.L.

    1985-04-01

    Located about 2 mi offshore and several miles east of Prudhoe Bay, the Endicott field contains about 1.4 billion reservoir bbl of oil and 0.5 billion reservoir bbl of gas. Hydrocarbons occur within Mississippian fluvial sandstones of the Kekiktuk formation, which unconformably overlies the Neruokpuk Formation and grades upward into the Kayak and Itkilyariak formations. Stratigraphy is subdivided into three lithofacies that, from the base upward, reflect deposition in a swamp/lacustrine/flood plain environment (zone I), a braided stream system (zone 2), and a meandering stream system (zone 3). Sediment dispersal was from a northerly source. Endicott field structure defines a southwesterly plunging antiform that is bounded to the north, northeast, and southwest by major normal faults and is truncated to the northeast by the Lower Cretaceous Unconformity (LCU). Shales overlying the LCU and shales of the Kayak and Itkilyariak formations from the reservoir cap. Reservoir properties with the hydrocarbon column vary by zone with zones 3 and 2 typified by an average net/gross-porosity-water saturation-permeability of 37%-18%-22%-500 md and 88%-22%-13%-1100 md, respectively. In contrast, zone 1 quality is very poor. Reservoir sands are compositionally very mature and exhibit an enhanced pore network. Diagenetic minerals include quartz along with lesser kaolinite and carbonate. Gas is present from about 9500 ft (2850 m) to 9855 ft (2958 m), oil is down to 10,180-10,200 ft (3054-3060 m), and tar accumulations are down to 10,400 ft (3120 m) subsea. Average oil gravity is 23/sup 0/ API. Geochemical data indicate that the tar accumulations originated through a physical deasphaltine process. Cenozoic imbibition resulted in water overriding tar.

  10. Contributions of transported Prudhoe Bay oil field emissions to the aerosol population in Utqiagvik, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Gunsch, Matthew J.; Kirpes, Rachel M.; Kolesar, Katheryn R.; Barrett, Tate E.; China, Swarup; Sheesley, Rebecca J.; Laskin, Alexander; Wiedensohler, Alfred; Tuch, Thomas; Pratt, Kerri A.

    2017-01-01

    Loss of sea ice is opening the Arctic to increasing development involving oil and gas extraction and shipping. Given the significant impacts of absorbing aerosol and secondary aerosol precursors emitted within the rapidly warming Arctic region, it is necessary to characterize local anthropogenic aerosol sources and compare to natural conditions. From August to September 2015 in Utqiagvik (Barrow), AK, the chemical composition of individual atmospheric particles was measured by computer-controlled scanning electron microscopy with energy-dispersive X-ray spectroscopy (0.13–4 µm projected area diameter) and real-time single-particle mass spectrometry (0.2–1.5 µm vacuum aerodynamic diameter). During periods influenced by the Arctic Ocean (70 % of the study), our results show that fresh sea spray aerosol contributed ~20 %, by number, of particles between 0.13 and 0.4 µm, 40–70 % between 0.4 and 1 µm, and 80–100 % between 1 and 4 µm particles. In contrast, for periods influenced by emissions from Prudhoe Bay (10 % of the study), the third largest oil field in North America, there was a strong influence from submicron (0.13–1 µm) combustion-derived particles (20–50 % organic carbon, by number; 5–10% soot by number). While sea spray aerosol still comprised a large fraction of particles (90 % by number from 1 to 4 µm) detected under Prudhoe Bay influence, these particles were internally mixed with sulfate and nitrate indicative of aging processes during transport. In addition, the overall mode of the particle size number distribution shifted from 76 nm during Arctic Ocean influence to 27 nm during Prudhoe Bay influence, with particle concentrations increasing from 130 to 920 cm-3 due to transported particle emissions from the oil fields. The increased contributions of carbonaceous combustion products and partially aged sea spray aerosol should be considered in future Arctic atmospheric composition and climate simulations.

  11. Contributions of transported Prudhoe Bay oil field emissions to the aerosol population in Utqiaġvik, Alaska

    Science.gov (United States)

    Gunsch, Matthew J.; Kirpes, Rachel M.; Kolesar, Katheryn R.; Barrett, Tate E.; China, Swarup; Sheesley, Rebecca J.; Laskin, Alexander; Wiedensohler, Alfred; Tuch, Thomas; Pratt, Kerri A.

    2017-09-01

    Loss of sea ice is opening the Arctic to increasing development involving oil and gas extraction and shipping. Given the significant impacts of absorbing aerosol and secondary aerosol precursors emitted within the rapidly warming Arctic region, it is necessary to characterize local anthropogenic aerosol sources and compare to natural conditions. From August to September 2015 in Utqiaġvik (Barrow), AK, the chemical composition of individual atmospheric particles was measured by computer-controlled scanning electron microscopy with energy-dispersive X-ray spectroscopy (0.13-4 µm projected area diameter) and real-time single-particle mass spectrometry (0.2-1.5 µm vacuum aerodynamic diameter). During periods influenced by the Arctic Ocean (70 % of the study), our results show that fresh sea spray aerosol contributed ˜ 20 %, by number, of particles between 0.13 and 0.4 µm, 40-70 % between 0.4 and 1 µm, and 80-100 % between 1 and 4 µm particles. In contrast, for periods influenced by emissions from Prudhoe Bay (10 % of the study), the third largest oil field in North America, there was a strong influence from submicron (0.13-1 µm) combustion-derived particles (20-50 % organic carbon, by number; 5-10 % soot by number). While sea spray aerosol still comprised a large fraction of particles (90 % by number from 1 to 4 µm) detected under Prudhoe Bay influence, these particles were internally mixed with sulfate and nitrate indicative of aging processes during transport. In addition, the overall mode of the particle size number distribution shifted from 76 nm during Arctic Ocean influence to 27 nm during Prudhoe Bay influence, with particle concentrations increasing from 130 to 920 cm-3 due to transported particle emissions from the oil fields. The increased contributions of carbonaceous combustion products and partially aged sea spray aerosol should be considered in future Arctic atmospheric composition and climate simulations.

  12. Oilfield geothermal exploitation in China-A case study from the Liaohe oilfield in Bohai Bay Basin

    Science.gov (United States)

    Wang, Shejiao; Yao, Yanhua; Fan, Xianli; Yan, Jiahong

    2017-04-01

    The clean geothermal energy can play a huge role in solving the problem of severe smog in China as it can replace large coal-fired heating in winter. Chinese government has paid close attention on the development and utilization of geothermal energy. In the "13th Five-Year" plan, the geothermal development is included into the national plan for the first time. China is very rich in the medium and low-temperature geothermal resources, ranking first in the geothermal direct use in the world for a long time. The geothermal resources are mainly concentrated in sedimentary basins, especially in petroliferous basins distributed in North China (in North China, heating is needed in winter). These basins are usually close to the large- and medium-sized cities. Therefore, tapping oilfield geothermal energy have attracted a great attention in the last few years as the watercut achieved above 90% in most oilfields and significant progress has been made. In this paper, taking the Liaohe Oilfield in the Bohai Bay Basin as an example, we discussed the distribution and potential of the geothermal resources, discussed how to use the existed technology to harness geothermal energy more effectively, and forecasted the development prospect of the oilfield geothermal energy. By using the volumetric method, we calculated the geothermal resources of the Guantao Formation, Dongying Formation, Shahejie Formation and basement rock in the Liaohe depression. We tested the geothermal energy utilization efficiency in different conditions by applying different pump technologies and utilizing geothermal energy in different depth, such as shallow geothermal energy (0-200m), middle-deep depth geothermal energy (200-4000m), and oilfield sewage heat produced with oil production. For the heat pump systems, we tested the conventional heat pump system, high-temperature heat pump system, super high-temperature heat pump system, and gas heat pump system. Finally, based on the analysis of national policy

  13. Aliphatic and aromatic hydrocarbon, organochlorine pesticide, and trace element concentrations in six fox livers from the Prudhoe Bay Oilfield, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This study was a portion of a multi-year assessment of contaminant concentrations from a variety of biotic and abiotic samples on the North Slope of Alaska. The...

  14. Genetic relationships of grizzly bears (Ursus arctos) in the Prudhoe Bay region of Alaska: inference from microsatellite DNA, mitochondrial DNA, and field observations.

    Science.gov (United States)

    Cronin, M; Shideler, R; Hechtel, J; Strobeck, C; Paetkau, D

    1999-01-01

    Grizzly bears are abundant in the region of the Prudhoe Bay oil fields in northern Alaska. We used field observations and molecular genetic data to identify parent-offspring and sibling relationships among bears in this region. We determined genotypes at 14 microsatellite DNA loci and the cytochrome b gene of mitochondrial DNA (mtDNA) for 36 bears. We identified 17 possible mother-offspring pairs and 8 possible father-offspring pairs. This includes verification of the relationships of 14 mother-offspring pairs identified from field observations. Three additional mother-offspring pairs and all eight father-offspring pairs were determined from genetic and age data. Relatedness coefficients based on numbers of shared alleles between individuals were as expected: approximately 0.50 for parent-offspring and sibling pairs and approximately 0.75 for a father-offspring pair resulting from a father-daughter mating. The level of genetic variation (mean number of alleles per locus = 6.6, mean heterozygosity = 70%) and allele frequencies in grizzly bears in the Prudhoe Bay region are similar to those in other parts of the species' range.

  15. k179ar.m77t - MGD77 data file for Geophysical data from field activity K-1-79-AR in Prudhoe Bay, Alaska, Arctic Ocean from 07/23/1979 to 08/20/1979

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Single-beam bathymetry data along with DGPS navigation data was collected as part of field activity K-1-79-AR in Prudhoe Bay, Alaska, Arctic Ocean from 07/23/1979 to...

  16. Molecular and isotopic analyses of the hydrocarbon gases within gas hydrate-bearing rock units of the Prudhoe Bay-Kuparuk River area in northern Alaska

    Science.gov (United States)

    Valin, Zenon C.; Collett, Timothy S.

    1992-01-01

    Gas hydrates, which are crystalline substances of water molecules that encase gas molecules, have the potential for being a significant source of natural gas. World-wide estimates for the amount of gas contained in hydrates range from 1.1 x 105 to 2.7 x 108 trillion cubic feet. Gas hydrates exist in many Arctic regions, including the North Slope of Alaska. The two primary objectives of the U.S. Geological Survey Gas Hydrate Research Project are (1) to map the distribution of in-situ gas hydrates on the North Slope of Alaska, and (2) to evaluate the geologic parameters that control the distribution of these gas hydrates. To aid in this study, British Petroleum Exploration, ARCO Alaska, Exxon Company USA, and the Continental Oil Company allowed the U.S. Geological Survey to collect geochemical samples from drilling North Slope production wells. Molecular analysis of gaseous drill cutting and free-flowing gas samples from 10 production wells drilled in the Prudhoe Bay, Kuparuk River, and Milne Point oil fields indicates that methane is the primary hydrocarbon gas in the gas hydrate-bearing stratigraphic units. Isotopic data for several of these rock units indicate that the methane within the inferred gas hydrate occurences originated from both microbial and thermogenic processes.

  17. Exposure and effects of oilfield brine discharges on western sandpipers (Calidris mauri) in Nueces Bay, Texas

    Energy Technology Data Exchange (ETDEWEB)

    Rattner, B.A.; Melancon, M.J. [National Biological Survey, Laurel, MD (United States); Capizzi, J.L. [Texas A& M Univ., College Station, TX (United States); King, K.A. [Fish and Wildlife Service, Phoenix, AZ (United States); LeCaptain, L.J. [Fish and Wildlife Service, Spokane, WA (United States)

    1995-05-01

    Discharge of oilfield brines into fresh and estuarine waters is a common disposal practice in Texas. Petroleum crude oil (PCO) extraction from underground stores includes the removal of a significant amount of water along with the oil. Several methods may be used to separate the oil and water fractions, including tank batteries, heat separation, and skimming ponds. Disposal of the resultant produced water (oilfield brine) may be accomplished by deep-well injection or discharge to surface waters. In Texas, an estimated 766,000 barrels of oilfield brine were discharged daily into tidal waters in 1979. The maximum concentration for oil and grease in these discharges permitted by the Texas Railroad Commission is 25 ppm. Several studies have shown that oilfield brines are toxic to a wide range of marine life, yet little is known about their effects on birds and mammals. Exposure to petroleum in oilfield wastes could evoke toxicological effects in some waterbird species. Avian responses to PCO exposure are highly variable, including cessation of growth, osmoregulatory impairment, endocrine dysfunction, hemolytic anemia, altered blood chemistry, cytochrome P450 induction, reduced reproductive success, and mortality. Oilfield brine discharges may soon be the largest and most pervasive source of contaminants entering Texas estuaries. Migratory and resident birds feeding in the vicinity of discharge sites may be ingesting food items contaminated with petroleum hydrocarbons, heavy metals and salts in sufficient quantities to evoke toxicity. The present study of wintering western sandpipers (Calidris mauri) that feed and roost near discharge sites sought to examine oilfield brine exposure and effects through quantification of contaminant burdens, morphological characteristics, and cytochrome P450-associated monooxygenase activities. 20 refs., 2 tabs.

  18. Resource Characterization and Quantification of Natural Gas-Hydrate and Associated Free-Gas Accumulations in the Prudhoe Bay - Kuparuk River Area on the North Slope of Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Shirish Patil; Abhijit Dandekar

    2008-12-31

    Natural gas hydrates have long been considered a nuisance by the petroleum industry. Hydrates have been hazards to drilling crews, with blowouts a common occurrence if not properly accounted for in drilling plans. In gas pipelines, hydrates have formed plugs if gas was not properly dehydrated. Removing these plugs has been an expensive and time-consuming process. Recently, however, due to the geologic evidence indicating that in situ hydrates could potentially be a vast energy resource of the future, research efforts have been undertaken to explore how natural gas from hydrates might be produced. This study investigates the relative permeability of methane and brine in hydrate-bearing Alaska North Slope core samples. In February 2007, core samples were taken from the Mt. Elbert site situated between the Prudhoe Bay and Kuparuk oil fields on the Alaska North Slope. Core plugs from those core samples have been used as a platform to form hydrates and perform unsteady-steady-state displacement relative permeability experiments. The absolute permeability of Mt. Elbert core samples determined by Omni Labs was also validated as part of this study. Data taken with experimental apparatuses at the University of Alaska Fairbanks, ConocoPhillips laboratories at the Bartlesville Technology Center, and at the Arctic Slope Regional Corporation's facilities in Anchorage, Alaska, provided the basis for this study. This study finds that many difficulties inhibit the ability to obtain relative permeability data in porous media-containing hydrates. Difficulties include handling unconsolidated cores during initial core preparation work, forming hydrates in the core in such a way that promotes flow of both brine and methane, and obtaining simultaneous two-phase flow of brine and methane necessary to quantify relative permeability using unsteady-steady-state displacement methods.

  19. RESOURCE CHARACTERIZATION AND QUANTIFICATION OF NATURAL GAS-HYDRATE AND ASSOCIATED FREE-GAS ACCUMULATIONS IN THE PRUDHOE BAY - KUPARUK RIVER AREA ON THE NORTH SLOPE OF ALASKA

    Energy Technology Data Exchange (ETDEWEB)

    Robert Hunter; Shirish Patil; Robert Casavant; Tim Collett

    2003-06-02

    Interim results are presented from the project designed to characterize, quantify, and determine the commercial feasibility of Alaska North Slope (ANS) gas-hydrate and associated free-gas resources in the Prudhoe Bay Unit (PBU), Kuparuk River Unit (KRU), and Milne Point Unit (MPU) areas. This collaborative research will provide practical input to reservoir and economic models, determine the technical feasibility of gas hydrate production, and influence future exploration and field extension of this potential ANS resource. The large magnitude of unconventional in-place gas (40-100 TCF) and conventional ANS gas commercialization evaluation creates industry-DOE alignment to assess this potential resource. This region uniquely combines known gas hydrate presence and existing production infrastructure. Many technical, economical, environmental, and safety issues require resolution before enabling gas hydrate commercial production. Gas hydrate energy resource potential has been studied for nearly three decades. However, this knowledge has not been applied to practical ANS gas hydrate resource development. ANS gas hydrate and associated free gas reservoirs are being studied to determine reservoir extent, stratigraphy, structure, continuity, quality, variability, and geophysical and petrophysical property distribution. Phase 1 will characterize reservoirs, lead to recoverable reserve and commercial potential estimates, and define procedures for gas hydrate drilling, data acquisition, completion, and production. Phases 2 and 3 will integrate well, core, log, and long-term production test data from additional wells, if justified by results from prior phases. The project could lead to future ANS gas hydrate pilot development. This project will help solve technical and economic issues to enable government and industry to make informed decisions regarding future commercialization of unconventional gas-hydrate resources.

  20. SOHIO (Standard Oil Co. , Ohio) to sell Prudhoe gas to Northern Natural Gas Co

    Energy Technology Data Exchange (ETDEWEB)

    1979-08-20

    Sohio has agreed to sell Vertical Bar3: 2 trillion cu ft of its Prudhoe Bay gas to Northern Natural Gas Co. for delivery at a rate of 170 million cu ft/day when the proposed Alaska Highway gas pipeline is completed. With the exception of approx. 4 trillion cu ft of Sohio's reserves committed to Columbia Gas System Inc., the agreement accounts for the sale of all the 26.5-27 trillion cu ft of Prudhoe Bay reserves. The contract, which is subject to approval of the U.S. Federal Energy Regulatory Commission, allows Alaska to take its one-eighth royalty share of the gas in kind or cash. Columbia Gas is the only firm planning to purchase Prudhoe Bay gas that is not participating as an equity owner in the pipeline project. According to a Columbia spokesman, it is still uncertain whether the proposed gas pipeline will be built; and the fact that Columbia has not yet signed a final agreement with Sohio does not indicate any decreasing interest in Prudhoe Bay gas.

  1. Embedded digital oilfield model

    Science.gov (United States)

    Korovin, Iakov S.; Boldyreff, Anton S.

    2017-10-01

    In modern hard conditions for the whole worldwide oil production industry the problem of increasing volumes of produced oil has recently become vital. This problem concerns the existing oilfields cause due to low crude oil prices the possibilities to drill new ones has almost disappeared. In this paper, we describe a novel approach of oil production enhancement, based on online procedures of all oil field data processing. The essence is that we have developed a dynamic oilfield model that allows to simultaneously handle the information, stored in tNavigator, Schlumberger ECLIPSE 100/300 and other `popular' formats in parallel. The model is developed on the basis of convolutional neural networks. An example of successful industrial experiment is depicted.

  2. Vegetation and Environmental Gradients of the Prudhoe Bay Region, Alaska,

    Science.gov (United States)

    1985-09-01

    Numerous taxonomists generously helped with the plant identifications. Dr. David Murray, University of Alaska Museum, and Dr. William Weber...Britton reviewed this work, and his comments are much appreciated. David Cate, CRREL, made numerous very helpful suggestions and has greatly helped the...111,, NOIA MNSCTAI 13.03 03 03 03 03 03 03 03 03 03 03 03 031 03 03 91 I1i IfIN LITRCOT O 03 0O) O ) 3 0 0 ) O 03 0 ( 3 0 ( .5 0( 1 L IV[ P’WORTS 1 7 3

  3. TX, OK, NM- Oilfield pollution

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Open oilfield pits and tanks as well as a proliferation of production saltwater spills continue to impact migratory birds and other resident fish and wildlife...

  4. White Rose oilfield comprehensive study report : final

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-04-01

    The potential environmental effects, including those resulting from malfunctions or accidents as well as any cumulative environmental effects of the White Rose oilfield development project are described in this Comprehensive Study Report. The report was prepared in accordance with the requirements of the Canadian Environmental Assessment Act. The White Rose oilfield development project is a proposed energy project aimed at recovering approximately 36 million cubic meters (230 million barrels) of recoverable oil. The deposits are contained in an area that covers approximately 40 square kilometers. It is located approximately 350 km east of Newfoundland on the eastern edge of the Jeanne d'Arc Basin. The oilfield is also located 50 km from both the Terra Nova and Hibernia oilfields. Husky Oil Operations Limited (Husky Oil), a major presence in the region, is working in a co-venture with Petro-Canada. Husky Oil submitted the Comprehensive Study Report on behalf of both partners. Both companies are seeking the appropriate regulatory approvals for the development of the White Rose oilfield. The document describes the regulatory context, scope of the project and the scope of the environmental assessment. Section 2 details the proposed White Rose oilfield development, while section 3 describes the assessment methodology. Section 4 is concerned with the environmental effects assessment and section 5 discusses the socio-economic effects assessment. 53 refs., 11 tabs., 8 figs.

  5. Environmental Engineering and Ecological Baseline Investigations along the Yukon River-Prudhoe Bay Haul Road.

    Science.gov (United States)

    1980-09-01

    Interior, uplands with only modest chamissonis, Carex albonigra, Draba cana, D. ma- topographic relief support taiga in its various counii, Erigeron...vegetation, land- been found on dry bluffs and terraces formed by form, microrelief, and slope information similar the Sagavanirktok River include Carex ...to refine our distribution maps for Arenaria *Prepared by D.A. Walker and P.1. Webber 45 L .. il l Iii . .. . ... -.... .. OF- . . -T . . . Table 10

  6. Sensitivity of Plant Communities and Soil Flora to Seawater Spills, Prudhoe Bay, Alaska,

    Science.gov (United States)

    1983-09-01

    within the profile. A similar during the 1980 observation period: Saxifraga op- situation probably prevails, but to a lesser extent, positifolia on the dry...Cassiope tetragona and Saxifraga oppositifolia, regardless of differences in microrelief (Fig. 7a-d). species that are of moderate importance in the...ssp. !-41ndifolia Saxifraga cernua L. Saxaragafoliolosa R. Br. Saxifraga hirculus L. Saxifraga opposififolia L. ssp. opposiifolia Sedum rosea (L

  7. Pre-ABoVE: Remotely Sensed Active Layer Thickness, Prudhoe Bay, Alaska, 1992-2000

    Data.gov (United States)

    National Aeronautics and Space Administration — Active layer thickness (ALT) is a critical parameter for monitoring the status of permafrost that is typically measured at specific locations using probing, in situ...

  8. Electromagnetic Measurements in an Active Oilfield Environment

    Science.gov (United States)

    Schramm, K. A.; Aldridge, D. F.; Bartel, L. C.; Knox, H. A.; Weiss, C. J.

    2015-12-01

    An important issue in oilfield development pertains to mapping and monitoring of the fracture distributions (either natural or man-made) controlling subsurface fluid flow. Although microseismic monitoring and analysis have been used for this purpose for several decades, there remain several ambiguities and uncertainties with this approach. We are investigating a novel electromagnetic (EM) technique for detecting and mapping hydraulic fractures in a petroleum reservoir by injecting an electrically conductive contrast agent into an open fracture. The fracture is subsequently illuminated by a strong EM field radiated by a large engineered antenna. Specifically, a grounded electric current source is applied directly to the steel casing of the borehole, either at/near the wellhead or at a deep downhole point. Transient multicomponent EM signals (both electric and magnetic) scattered by the conductivity contrast are then recorded by a surface receiver array. We are presently utilizing advanced 3D numerical modeling algorithms to accurately simulate fracture responses, both before and after insertion of the conductive contrast agent. Model results compare favorably with EM field data recently acquired in a Permian Basin oilfield. However, extraction of the very-low-amplitude fracture signatures from noisy data requires effective noise suppression strategies such as long stacking times, rejection of outliers, and careful treatment of natural magnetotelluric fields. Dealing with the ever-present "episodic EM noise" typical in an active oilfield environment (associated with drilling, pumping, machinery, traffic, etc.) constitutes an ongoing problem. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  9. Oilfield Flare Gas Electricity Systems (OFFGASES Project)

    Energy Technology Data Exchange (ETDEWEB)

    Rachel Henderson; Robert Fickes

    2007-12-31

    The Oilfield Flare Gas Electricity Systems (OFFGASES) project was developed in response to a cooperative agreement offering by the U.S. Department of Energy (DOE) and the National Energy Technology Laboratory (NETL) under Preferred Upstream Management Projects (PUMP III). Project partners included the Interstate Oil and Gas Compact Commission (IOGCC) as lead agency working with the California Energy Commission (CEC) and the California Oil Producers Electric Cooperative (COPE). The project was designed to demonstrate that the entire range of oilfield 'stranded gases' (gas production that can not be delivered to a commercial market because it is poor quality, or the quantity is too small to be economically sold, or there are no pipeline facilities to transport it to market) can be cost-effectively harnessed to make electricity. The utilization of existing, proven distribution generation (DG) technologies to generate electricity was field-tested successfully at four marginal well sites, selected to cover a variety of potential scenarios: high Btu, medium Btu, ultra-low Btu gas, as well as a 'harsh', or high contaminant, gas. Two of the four sites for the OFFGASES project were idle wells that were shut in because of a lack of viable solutions for the stranded noncommercial gas that they produced. Converting stranded gas to useable electrical energy eliminates a waste stream that has potential negative environmental impacts to the oil production operation. The electricity produced will offset that which normally would be purchased from an electric utility, potentially lowering operating costs and extending the economic life of the oil wells. Of the piloted sites, the most promising technologies to handle the range were microturbines that have very low emissions. One recently developed product, the Flex-Microturbine, has the potential to handle the entire range of oilfield gases. It is deployed at an oilfield near Santa Barbara to run on waste gas

  10. Electromagnetic Measurements in an Active Oilfield Environment

    Science.gov (United States)

    Weiss, C. J.; Aur, K. A.; Schramm, K. A.; Aldridge, D. F.; O'rourke, W. T.

    2016-12-01

    An important issue in oilfield development is mapping fracture distributions (either natural or man-made) controlling subsurface fluid flow. Although microseismic monitoring has been successful in constraining fracture system geometry and dynamics, accurate interpretation of microseismic data can be confounded by factors such as complex or poorly-understood velocity distributions, reactivation of previously unknown faults and fractures, and the problem of relating flow patterns to the cloud of hypocenter locations. For the particular problem of hydrocarbon production, the question of which fractures remain sufficiently "open" to allow economical fluid extraction is critical. As a supplement to microseismic analysis, we are investigating a novel electromagnetic (EM) technique for detecting and mapping hydraulic fractures in a hydrocarbon or geothermal reservoir by introducing an electrically conductive contrast agent into the fracturing fluid. In the field experiment presented here, a proppant-filled fracture zone is illuminated by a large engineered antenna consisting of an insulated current-carrying cable, grounded to `Earth' near the wellhead, and grounded at the other end to the steel-cased borehole near the target. Time-lapse measurements of horizontal electric field are subsequently made on Earth's surface to map the change in subsurface conductivity due to proppant emplacement. As predicted by 3D numerical modelling, observed differences in electric field values are very small. While these numbers are above the noise floor of electric field sensors, pervasive anthropogenic EM noise and regional-scale magnetotelluric signals make extraction of the differences from the observed time series especially difficult. We present field-acquired data on ambient EM noise in an active oilfield environment and demonstrate techniques for extracting the difference signal due to proppant emplacement. These techniques include classical spectral methods along with estimation of

  11. Exploitation and Utilization of Oilfield Geothermal Resources in China

    Directory of Open Access Journals (Sweden)

    Shejiao Wang

    2016-09-01

    Full Text Available Geothermal energy is a clean, green renewable resource, which can be utilized for power generation, heating, cooling, and could effectively replace oil, gas, and coal. In recent years, oil companies have put more efforts into exploiting and utilizing geothermal energy with advanced technologies for heat-tracing oil gathering and transportation, central heating, etc., which has not only reduced resource waste, but also improved large-scale and industrial resource utilization levels, and has achieved remarkable economic and social benefits. Based on the analysis of oilfield geothermal energy development status, resource potential, and exploitation and utilization modes, the advantages and disadvantages of harnessing oilfield geothermal resource have been discussed. Oilfield geothermal energy exploitation and utilization have advantages in resources, technical personnel, technology, and a large number of abandoned wells that could be reconstructed and utilized. Due to the high heat demand in oilfields, geothermal energy exploitation and utilization can effectively replace oil, gas, coal, and other fossil fuels, and has bright prospects. The key factors limiting oilfield geothermal energy exploitation and utilization are also pointed out in this paper, including immature technologies, lack of overall planning, lack of standards in resource assessment, and economic assessment, lack of incentive policies, etc.

  12. Behavior and fate of spilled Prudhoe crude upon the Atigun River flood plain: Phase II, August 6-7 field assessment

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Observations obtained during the August 6th - 7th field surveys are part of the continuing assessment of the fate and effects of spilled Prudhoe crude upon the...

  13. Oilfield Production Surveillance as a Management Tool for ...

    African Journals Online (AJOL)

    Production problems such as sand production, emulsion, corrosion, scale formation and wax blockage can lead to disposal problems and poor integrity of facilities and consequent financial losses. This paper presents a system approach for carrying out oilfield production surveillance process. Using case studies it is

  14. The Environmental Impact of Oilfield Formation Water on a ...

    African Journals Online (AJOL)

    The environmental impact resulting from the discharge of treated oilfield formation water into freshwater samples collected from this stream with no previous history of pollution from oil exploration activities was assessed in terms of changes in water quality parameters such as Dissolved oxygen (DO), Biochemical oxygen ...

  15. Microbiologically influenced corrosion of oilfield producing well equipment

    Energy Technology Data Exchange (ETDEWEB)

    Littmann, E.S.

    1987-01-01

    This oilfield has been waterflooded for many years. After it was placed under polymer flood, severe corrosion was noted in the producing wells. This corrosion appears to be related to polymer breakthrough. Extensive analyses including various microbiological techniques strongly indicated bacterial involvement and a successful program of biocide treatments were begun on the wells.

  16. Causes and preventive management of scale formation in oilfield ...

    African Journals Online (AJOL)

    Scale formation in oilfield operations causes lot problems. In the reservoir, it reduces near wellbore permeability, resulting in high skin and lower inflow. In wells it causes flow restriction resulting in higher pressure losses or lower throughput. Moreover, in flow lines and surface facilities, it causes loss of equipment ...

  17. Analysis of technological conditions influence on efficiency of oilfield treatment

    Science.gov (United States)

    Usheva, N. V.; Moizes, O. E.; Kuzmenko, E. A.; Kim, S. F.; Khlebnikova, E. S.; Dyalilova, S. N.; Filippova, T. V.

    2015-11-01

    The results of influence of process parameters on oil quality and recommended effective technological modes of oilfield treatment processes are presented in this paper. It is shown that the parameters that significantly affect the efficiency of oil processes are temperature and water-oil emulsion flow rate with a given number of working process units and the structure of flowsheet flows.

  18. Nuclear Tools For Oilfield Logging-While-Drilling Applications

    Science.gov (United States)

    Reijonen, Jani

    2011-06-01

    Schlumberger is an international oilfield service company with nearly 80,000 employees of 140 nationalities, operating globally in 80 countries. As a market leader in oilfield services, Schlumberger has developed a suite of technologies to assess the downhole environment, including, among others, electromagnetic, seismic, chemical, and nuclear measurements. In the past 10 years there has been a radical shift in the oilfield service industry from traditional wireline measurements to logging-while-drilling (LWD) analysis. For LWD measurements, the analysis is performed and the instruments are operated while the borehole is being drilled. The high temperature, high shock, and extreme vibration environment of LWD imposes stringent requirements for the devices used in these applications. This has a significant impact on the design of the components and subcomponents of a downhole tool. Another significant change in the past few years for nuclear-based oilwell logging tools is the desire to replace the sealed radioisotope sources with active, electronic ones. These active radiation sources provide great benefits compared to the isotopic sources, ranging from handling and safety to nonproliferation and well contamination issues. The challenge is to develop electronic generators that have a high degree of reliability for the entire lifetime of a downhole tool. LWD tool testing and operations are highlighted with particular emphasis on electronic radiation sources and nuclear detectors for the downhole environment.

  19. Fish impacts in the Atigun River from Prudhoe Bay crude oil: Investigations of Phase I and II

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes Phase I and II, Environmental Protection Agency funded damage assessment investigation on fish observation in the Atigun River associated with...

  20. A Study of the Incremental Trend of the Reserves in Daqing Oilfield and Its Controlling Factors

    Science.gov (United States)

    LI, Jiaguang; GUO, Shaobin; CHEN, Zhaoyu

    Daqing Oilfield is the biggest petroleum production base in China, its total production of crude oil accounts for over 40% of the total production of the mainland in the same period, and its exploitation situation directly influences the national-wide supply of the crude oil. In recent years, because the production of Daqing Oilfield gradually decreases and the domestic energy supply falls short, the increase in the production of oil and gas resources draws the attention by the public. This article, based on the collection of a great number of original data form Daqing Oilfield, in combination with the intrinsic characteristics of Daqing Oilfield, adopts the reserve growth prediction method to make an estimate of the newly added recoverable reserve in Daqing Oilfield. The result shows that the newly added resources in Daqing Oilfield present a downward trend, and the time for finally recoverable reserve will be at 2028. This article also analyzes the main controlling factors for the change trend of newly added oil and gas resources from international and domestic respects and draws a conclusion that the fluctuation of international crude oil price and the guiding direction of the domestic policy as well as the technology progress are the main reasons that influence the newly added oil and gas resources in Daqing Oilfield.

  1. The Method of Oilfield Development Risk Forecasting and Early Warning Using Revised Bayesian Network

    Directory of Open Access Journals (Sweden)

    Yihua Zhong

    2016-01-01

    Full Text Available Oilfield development aiming at crude oil production is an extremely complex process, which involves many uncertain risk factors affecting oil output. Thus, risk prediction and early warning about oilfield development may insure operating and managing oilfields efficiently to meet the oil production plan of the country and sustainable development of oilfields. However, scholars and practitioners in the all world are seldom concerned with the risk problem of oilfield block development. The early warning index system of blocks development which includes the monitoring index and planning index was refined and formulated on the basis of researching and analyzing the theory of risk forecasting and early warning as well as the oilfield development. Based on the indexes of warning situation predicted by neural network, the method dividing the interval of warning degrees was presented by “3σ” rule; and a new method about forecasting and early warning of risk was proposed by introducing neural network to Bayesian networks. Case study shows that the results obtained in this paper are right and helpful to the management of oilfield development risk.

  2. White Rose oilfield development application. CD-ROM ed.

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-01-01

    Located approximately 350 km east of Newfoundland, on the eastern edge of the Jeanne d'Arc Basin, and approximately 50 km from both the Terra Nova and Hibernia oilfields, the White Rose oilfield is considered the main oil producing basin off the eastern coast of North America. Husky Oil is very active in the region and holds almost 32 per cent net working interest in the Significant Discovery License areas in the Jeanne d'Arc basin. The development of an economically significant oil discovery in the White Rose Significant Discovery Area is being proposed jointly by Husky Oil and Petro-Canada. It is estimated that the project would enable the recovery of an estimated 36 million cubic meters (230 million barrels) of recoverable oil in this area that covers approximately 40 square kilometers. The operators propose to use a ship-shaped floating production, storage and offloading (FPSO) facility which could store up to 135,000 cubic meters (850,000 barrels) of oil or the equivalent of ten days of oil production. The facility would also provide topside processing units, accommodations and a turret. Both companies are seeking the appropriate regulatory approvals for the development of the White Rose oilfield. The document details the Development Application submitted by Husky Oil Operations Limited on behalf of both itself and the other party involved in the co-venture, Petro-Canada. This Development Application is divided in five volumes and a Project Summary. The five volumes each deal with a separate topic. Volume 1 describes the Canada-Newfoundland Benefits Plan and is divided into 7 sections describing everything from labour requirements to procurement requirements, development and production scenarios and more. Volume 2 details the Development Plan, which is divided into 14 sections such as project overview, geology and geophysics, petrophysics, reservoir engineering, original hydrocarbons in place, reservoir exploitation, development drilling and

  3. An application of sedimentation simulation in Tahe oilfield

    Science.gov (United States)

    Tingting, He; Lei, Zhao; Xin, Tan; Dongxu, He

    2017-12-01

    The braided river delta develops in Triassic low oil formation in the block 9 of Tahe oilfield, but its sedimentation evolution process is unclear. By using sedimentation simulation technology, sedimentation process and distribution of braided river delta are studied based on the geological parameters including sequence stratigraphic division, initial sedimentation environment, relative lake level change and accommodation change, source supply and sedimentary transport pattern. The simulation result shows that the error rate between strata thickness of simulation and actual strata thickness is small, and the single well analysis result of simulation is highly consistent with the actual analysis, which can prove that the model is reliable. The study area belongs to braided river delta retrogradation evolution process, which provides favorable basis for fine reservoir description and prediction.

  4. Determination of density pattern of fracture in Asmari Formation in Marun oilfield

    National Research Council Canada - National Science Library

    Kheyrollah Noraeinezhad; Hassan Amiri Bakhtiar; Heidar Basiri; Mehdi Khoshnodkia

    2015-01-01

    .... Given the important role of fracture characteristics for improving production, so the aim of this research is to investigate the density pattern of fracture in Asmari formation in Marun oilfield...

  5. Contaminants Investigation Bulletin: Environmental contaminants in sediments from oilfield produced water discharge points

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Trace element concentrations in sediment samples are shown in Table 2. Sediments from a wetland receiving oilfield produced water from the Arnell oil production site...

  6. Determination of density pattern of fracture in Asmari Formation in Marun oilfield

    OpenAIRE

    Mehdi Khoshnodkia; Heidar Basiri; Hassan Amiri Bakhtiar; Kheyrollah Noraeinezhad

    2015-01-01

    Marun oilfield is located in the middle part of Dezful Embayment and is situated along the Aghajari, Ahvaz and Ramin anticline. Given the important role of fracture characteristics for improving production, so the aim of this research is to investigate the density pattern of fracture in Asmari formation in Marun oilfield. For this purpose, results of image log, core data, graphic well log, methods of inscribed circle analysis and curvature changes geometry of anticline were analyzed. Asmari f...

  7. Copper removal from oil-field brine by coprecipitation.

    Science.gov (United States)

    Khosravi, Jafar; Alamdari, Abdolmohammad

    2009-07-30

    The present study aims at investigation of copper removal from oil-field brine by coprecipitation process. The produced brine containing heavy metals is usually returned to the reservoir for water flooding or is discarded to the surroundings. Therefore, surface waters or underground waters may be polluted due to probable contact to these discarded waters. Removal experiments were carried out at room temperature in a bench-scale crystallizer equipped with a draft tube. In order to gain an insight into the influence of soluble compounds in the industrial natural brine on the precipitation process, some comparative experiments were performed both on a sample of natural brine and on a synthetic simulated brine in the absence of natural impurities. A metal removal practice by coprecipitation of copper through CaCO(3) precipitates induced by reaction of Na(2)CO(3) and CaCl(2) reduced the copper concentration (Cu(2+)) from 0.27 ppm in the synthetic brine to 0.06 ppm. This removal of 78% required only 1g of precipitate per 0.15 mg copper metal. Analysis of the experimental results suggested that about 5% of the copper removal from the synthetic brine was through the mechanism of incorporation into the crystal lattice, and around 95% was through the adsorption on the crystal faces.

  8. Integrated inventory ranking system for oilfield equipment industry

    Directory of Open Access Journals (Sweden)

    Jalel Ben Hmida

    2014-01-01

    Full Text Available Purpose: This case study is motivated by the subcontracting problem in an oilfield equipment and service company where the management needs to decide which parts to manufacture in-house when the capacity is not enough to make all required parts. Currently the company is making subcontracting decisions based on management’s experience. Design/methodology/approach: Working with the management, a decision support system (DSS is developed to rank parts by integrating three inventory classification methods considering both quantitative factors such as cost and demand, and qualitative factors such as functionality, efficiency, and quality. The proposed integrated inventory ranking procedure will make use of three classification methods: ABC, FSN, and VED. Findings: An integration mechanism using weights is developed to rank the parts based on the total priority scores. The ranked list generated by the system helps management to identify about 50 critical parts to manufacture in-house. Originality/value: The integration of all three inventory classification techniques into a single system is a unique feature of this research. This is important as it provides a more inclusive, big picture view of the DSS for management’s use in making business decisions.

  9. Oilfield solids and water-in-oil emulsion stability.

    Science.gov (United States)

    Sztukowski, Danuta M; Yarranton, Harvey W

    2005-05-15

    Model water-in-hydrocarbon emulsions consisting of toluene, heptane, water, asphaltenes, and native solids were used to investigate the role of native solids in the stability of oilfield emulsions. The solids were recovered from an oil-sands bitumen, a wellhead emulsion, and a refinery slop oil. The solids were clay platelets and fell into two size categories: (1) fine solids 50 to 500 nm in diameter and (2) coarse solids 1 to 10 microm in diameter. Emulsions stabilized by fine solids and asphaltenes were most stable at a 2:1 fractional area ratio of asphaltenes to solids. It appears that when the asphaltene surface coverage is high, insufficient solids remain to make an effective barrier. When the solids coverage is high, insufficient asphaltenes remain on the interface to immobilize the solids. Treatments that weaken the interface, such as toluene dilution, are recommended for emulsions stabilized by fine solids. Emulsions stabilized by coarse solids were unstable at low solids concentrations but became very stable at solids concentrations greater than 10 kg/m(3). At low concentrations, these solids may act as bridges between water droplets and promote coalescence. At high concentrations, layers of coarse solids may become trapped between water droplets and prevent coalescence. Treatments that flocculate the solids, such as heptane dilution, are recommended for emulsions stabilized by high concentrations of coarse solids. It is possible that emulsions containing both types of solids may require more than one treatment, or even process step, for effective water resolution.

  10. Histological characterization of Sticholecitha serpentis Prudhoe, 1949 (digenea, bieriidae, sticholecithinae, parasite of Bothrops moojeni Hoge, 1966 (serpentes, viperidae

    Directory of Open Access Journals (Sweden)

    TB. Silva

    2005-12-01

    Full Text Available The aim of this study was to evaluate the morphology of the species Sticholecitha serpentis Prudhoe, 1949 by means of histological procedures. Helminths were previously fixed in Railliet & Henry solution, uncompressed and were included in 2-hydroxyethyl-methacrylate. Longitudinal and transverse serial sections with a 4-mum thickness were performed in a microtome (Leica RM 2165, stained with haematoxylin-eosin and then analyzed in a computerized image analysis system (Qwin Lite 2.5, Leica. Structures of systematic value, such as oral sucker, acetabulum, prepharynx, pharynx, esophagus, intestinal caeca, vitelline glands, ovary, uterus, cirrus pouch and testicles were described. Structures that were poorly visible in total preparations were also observed and described, such as efferent ducts, ejaculatory duct, prostate, seminal vesicle, seminal receptacle, Laurer’s channel, Mehlis’ gland, vitelline ducts, metraterm, genital atrium, digestive glands and excretory vesicle. We demonstrated that histological analysis can supply important data regarding the morphological characterization of S. serpentis and will be able to contribute to systematic studies of trematodes.

  11. Characterization of the microbial diversity in production waters of mesothermic and geothermic Tunisian oilfields.

    Science.gov (United States)

    Mnif, Sami; Bru-Adan, Valérie; Godon, Jean-Jacques; Sayadi, Sami; Chamkha, Mohamed

    2013-01-01

    The microbial diversity of production waters of five Tunisian oilfields was investigated using Single Strand Conformation Polymorphism (SSCP) technique followed by cloning-sequencing. Dynamics of bacterial populations in production waters collected from four wellheads were also evaluated. For all production water samples collected, DNA from Archaea and Eucarya was not sufficiently abundant to permit detection rRNA genes from these groups by PCR-SSCP. In contrast, the bacterial rRNA genes were detected in all samples, except for samples from DOULEB12 and RAMOURA wells. SSCP profiles attested that two of the studied geothermic wells (ASHTART47 and ASHTART48) had shown a clear change over time, whereas a stable diversity was found with the mesophilic DOULEB well (DL3). PCR amplification of rRNA genes was unsuccessful with samples from DOULEB (DL12) at all three sampling time. The bacterial diversity present in production waters collected from pipelines of SERCINA and LITAYEM oilfields was high, while production waters collected from wellheads (ASHTART and DOULEB) exhibited lower diversity. The partial study of the biodiversity showed a dominance of uncultured bacteria and Pseudomonas genus (class of the Gammaproteobacteria) in three of the studied oilfields (ASHTART47, ASHTART48 and DOULEB3). However, for LITAYEM oilfield, a significant dominance of 5 phyla (Proteobacteria, Thermotogae, Firmicutes, Synergistetes, Bacteroidetes) was shown. Our study gives a real picture of the microbiology of some Tunisian oilfield production waters and shows that some of the sequenced bacterial clones have a great similarity to previous sequenced clones described from other oilfields all over the world, indicating that these ecosystems harbour specific microbial communities. These findings can be considered as an indirect indication of the indigenous origin of these clones. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. A Mathematical Model for Predicting Output in an Oilfield in the ...

    African Journals Online (AJOL)

    In this paper, a multiple linear regression model was developed for forecasting crude oil production volume in an oilfield in the Niger Delta area of Nigeria. Data of crude oil production ... The significance of each regression coefficient at in the six variable model was subjected to further analysis. The regression coefficient ...

  13. a mathematical model for predicting output in an oilfield in the niger ...

    African Journals Online (AJOL)

    eobe

    6], developed. Multicyclic ... oil and gas producing industry in Nigeria for two years. The framework of this study was the identification of .... [4] Zhu, S.C and Zhao, X “Application of Artificial Neural. Network in the Prediction of Output in Oilfield,”.

  14. Physical chemical characteristics of oil emulsions of North-West Konys and Zhanaozen oilfields

    Directory of Open Access Journals (Sweden)

    Akbota Adilbekova

    2016-06-01

    Full Text Available Physical chemical properties of oil emulsions of two different oilfields of Kazakhstan - NorthWest Konys and Zhanaozen by their densities related to light and heavy oils, respectively, were studied. Qualitative and quantitative compositions of main stabilizing components of oil emulsions (resins, asphaltenes and high molecular paraffins were determined. The dispersion degree of oil emulsions was determined using optical microscopy. It was found that samples relate to fine dispersed oil emulsions by dispersion, and to poorly stable (Konys and highly stable (Zhanaozen oil emulsions by ability to form emulsions. Light oil of Konys oilfield (ρ = 833 kg/m3 at 20°C contains 11.5% of paraffins, 0.69% resins, 0.19% asphaltenes. The same measurements were carried out for heavy oil of Zhanaozen (943 kg/m3 at 20°C where paraffin content exceeded 30%, amount of resins was 1.5% and asphaltenes – 0.6%. The sample of Zhanaozen oilfield contains 33% of water, 154.8 mg/L chlorides, 5.22 % mechanical impurities, and for oilfield samples of North-West Konys the water content was 7.5%, the content of chloride salts – 18 mg/L, and 0.002% of mechanical impurities.

  15. White Rose oilfield comprehensive study and comprehensive study report. CD-ROM ed.

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-10-01

    Husky Oil Operations Limited (Husky Oil) is proposing to develop the White Rose oilfield, located approximately 350 km east of Newfoundland on the eastern edge of the Jeanne d'Arc Basin. The oilfield is also located approximately 50 km from both the Hibernia and Terra Nova oilfields. This project proposes the recovery of 36 million cubic meters (230 million barrels) of recoverable oil from the Jeanne d'Arc Basin, considered the main producing basin off the eastern coast of North America. The deposits are contained within an area that covers approximately 40 square kilometers. Husky Oil is involved in a co-venture with Petro-Canada and presented this Comprehensive Study on behalf of both partners. Both companies are seeking the appropriate regulatory approvals for the development of the White Rose oilfield. This CD-ROM contains an introduction and the project description. Part One details the Environmental Impact Statement, with sections touching on regional setting (physical environment), regional setting (biological environment), effects assessment, oil spills, mitigation measures and contingency planning, monitoring and reporting, and environmental management. Part Two of the document outlines the Socio-Economic Impact Statement. This part describes the assessment scope and methodology, economic and demographic context, business and employment, community social infrastructure and services, community physical infrastructure, and fisheries. This project will be assessed under the Canadian Environmental Assessment Act, as well as by the Canada-Newfoundland Offshore Petroleum Board (C-NOPB) under the Atlantic Accord Implementation Act. refs., tabs., figs.

  16. Sulfate-reducing bacteria release barium and radium from naturally occurring radioactive material in oil-field barite

    Science.gov (United States)

    Phillips, E.J.P.; Landa, E.R.; Kraemer, T.; Zielinski, R.

    2001-01-01

    Scale and sludge deposits formed during oil production can contain elevated levels of Ra, often coprecipitated with barium sulfate (barite). The potential for sulfate-reducing bacteria to release 226 Ra and Ba (a Ra analog) from oil-field barite was evaluated. The concentration of dissolved Ba increased when samples containing pipe scale, tank sludge, or oil-field brine pond sediment were incubated with sulfate-reducing bacteria Desulfovibrio sp., Str LZKI, isolated from an oil-field brine pond. However, Ba release was not stoichiometric with sulfide production in oil-field samples, and sulfate-reducing activity was predictable from the amount of Ba released. As with Ba, only a fraction of the 226Ra expected from the amount of sulfide produced was released, and most of the Ra remained associated with the solid material.

  17. Toxicity and water quality of natural waterbodies, reserve pits and selected sites at North Slope, Alaska, oilfields

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Oilfield activities on the North Slope of Alaska result in production of large amounts of wastes and fugitive dust. Surface storage and disposal of these wastes may...

  18. Data Analysis and Neuro-Fuzzy Technique for EOR Screening: Application in Angolan Oilfields

    Directory of Open Access Journals (Sweden)

    Geraldo A. R. Ramos

    2017-06-01

    Full Text Available In this work, a neuro-fuzzy (NF simulation study was conducted in order to screen candidate reservoirs for enhanced oil recovery (EOR projects in Angolan oilfields. First, a knowledge pattern is extracted by combining both the searching potential of fuzzy-logic (FL and the learning capability of neural network (NN to make a priori decisions. The extracted knowledge pattern is validated against rock and fluid data trained from successful EOR projects around the world. Then, data from Block K offshore Angolan oilfields are then mined and analysed using box-plot technique for the investigation of the degree of suitability for EOR projects. The trained and validated model is then tested on the Angolan field data (Block K where EOR application is yet to be fully established. The results from the NF simulation technique applied in this investigation show that polymer, hydrocarbon gas, and combustion are the suitable EOR techniques.

  19. A new approach of proration-injection allocation for water-flooding mature oilfields

    Directory of Open Access Journals (Sweden)

    Shuyong Hu

    2015-03-01

    Full Text Available This paper presents a new method of injection-production allocation estimation for water-flooding mature oilfields. The suggested approach is based on logistic growth rate functions and several type-curve matching methods. Using the relationship between these equations, oil production and water injection rate as well as injection-production ratio can be easily forecasted. The calculation procedure developed and outlined in this paper requires very few production data and is easily implemented. Furthermore, an oilfield case has been analyzed. The synthetic and field cases validate the calculation procedure, so it can be accurately used in forecasting production data, and it is important to optimize the whole injection-production system.

  20. Investigation of Multi-Criteria Decision Consistency: A Triplex Approach to Optimal Oilfield Portfolio Investment Decisions

    Science.gov (United States)

    Qaradaghi, Mohammed

    Complexity of the capital intensive oil and gas portfolio investments is continuously growing. It is manifested in the constant increase in the type, number and degree of risks and uncertainties, which consequently lead to more challenging decision making problems. A typical complex decision making problem in petroleum exploration and production (E&P) is the selection and prioritization of oilfields/projects in a portfolio investment. Prioritizing oilfields maybe required for different purposes, including the achievement of a targeted production and allocation of limited available development resources. These resources cannot be distributed evenly nor can they be allocated based on the oilfield size or production capacity alone since various other factors need to be considered simultaneously. These factors may include subsurface complexity, size of reservoir, plateau production and needed infrastructure in addition to other issues of strategic concern, such as socio-economic, environmental and fiscal policies, particularly when the decision making involves governments or national oil companies. Therefore, it would be imperative to employ decision aiding tools that not only address these factors, but also incorporate the decision makers' preferences clearly and accurately. However, the tools commonly used in project portfolio selection and optimization, including intuitive approaches, vary in their focus and strength in addressing the different criteria involved in such decision problems. They are also disadvantaged by a number of drawbacks, which may include lacking the capacity to address multiple and interrelated criteria, uncertainty and risk, project relationship with regard to value contribution and optimum resource utilization, non-monetary attributes, decision maker's knowledge and expertise, in addition to varying levels of ease of use and other practical and theoretical drawbacks. These drawbacks have motivated researchers to investigate other tools and

  1. Cracking and thermal maturity of Ordovician oils from Tahe Oilfield, Tarim Basin, NW China

    Directory of Open Access Journals (Sweden)

    Anlai Ma

    2017-12-01

    Full Text Available The thermal maturity of the Ordovician oils from the Tahe oilfield of Tarim Basin, NW China was assessed through various maturity parameters, such as biomarkers, aromatic parameters, and diamondoid parameters. Both Ts/(Ts+Tm and C29Ts/(C29H+C29Ts values indicate that the maturity of oils has not reached the condensates stage, which is consistent with the maturity obtained by MPI1. However, the diamondoid maturity suggests that the oil maturity ranges 1.1%–1.6% Ro, which is apparently higher than that of the maturity obtained by the biomarker and MPI1. This discrepancy in maturity may indicate that the Ordovician reservoir has multiple filling history. The 4-MD+3-MD concentration of oils disperses and increases slowly when the Ts/(Ts+Tm value is lower than 0.55. Meanwhile, the value increases rapidly when the Ts/(Ts+Tm value is higher than 0.55. It is proposed that the diamondoid baseline is about 15 μg/goil for marine oils in the Tahe oilfield based on the diamondoid concentration of marine oils from reservoirs of various age. The concentration of 4-MD+3-MD of most Ordovician oils generally ranges from 4.5 to 35 μg/goil, suggesting that the degree of oil-cracking is lower than 50% and the deep Ordovician have potential of oil exploration. The distribution of the concentration of 4-MD+3-MD is characterized by being high in the east and south, low in the west and north, proposing that the two migration pathways exit in the oilfield, which are from east to west and from south to north, respectively. The migration directions are consistent with the results obtained from the oil density and the maturity parameters such as Ts/(Ts+Tm. Thus, suggesting the concentration of 4-MD+3-MD can be used as migration index in oilfield scale.

  2. Removal of boron from oilfield wastewater via adsorption with synthetic layered double hydroxides.

    Science.gov (United States)

    Delazare, Thais; Ferreira, Letícia P; Ribeiro, Nielson F P; Souza, Mariana M V M; Campos, Juacyara C; Yokoyama, Lídia

    2014-01-01

    Hydrotalcite is a layered double hydroxide (LDH) consisting of brucite-like sheets of metal ions (Mg-Al). In this work, hydrotalcites were synthesized, and boron removal from oilfield wastewater was evaluated. LDHs were synthesized using the co-precipitation method. The calcined products (CLDHs) were obtained by heating at 500°C and characterized using X-ray diffraction, X-ray fluorescence, thermogravimetric analysis and the specific surface area (BET). The affinity of LDHs for borate ions was evaluated for calcined and uncalcined LDHs as a function of contact time, initial pH of the oilfield wastewater (pH ∼ 9) and the LDH surface area. The tests were conducted at room temperature (approximately 25ºC). The results indicated that 10 min were needed to reach a state of equilibrium during boron removal for calcined LDHs due to the high surface area (202.3 m(2) g(-1)) regardless of the initial pH of the oilfield wastewater, which resulted from the high buffering capacity of the LDHs. The adsorption capacity increased as the adsorbents levels increased for the range studied. After treatment of the oilfield wastewater containing 30 mg L(-1) of boron with Mg-Al-CO3-LDHs, the final concentration of boron was within the discharge limit set by current Brazilian environmental legislation, which is 5 mg L(-1). Pseudo-first-order and pseudo-second-order kinetic models were tested, and the latter was found to fit the experimental data better. Isotherms for boron adsorption by CLDHs were well described using the Langmuir and Freundlich equations.

  3. Determination of density pattern of fracture in Asmari Formation in Marun oilfield

    Directory of Open Access Journals (Sweden)

    Kheyrollah Noraeinezhad

    2015-05-01

    Full Text Available Marun oilfield is located in the middle part of Dezful Embayment and is situated along the Aghajari, Ahvaz and Ramin anticline. Given the important role of fracture characteristics for improving production, so the aim of this research is to investigate the density pattern of fracture in Asmari formation in Marun oilfield. For this purpose, results of image log, core data, graphic well log, methods of inscribed circle analysis and curvature changes geometry of anticline were analyzed. Asmari formation is the main reservoir rock in Marun oilfield that divided into five zones. Limestone and dolomite are the main lithology of zones 1, 2 and 3 which has a high density of fractures (especially in zones with 90% dolomite. Also there is less fracture density (micro fracture in the 4 and 5 Asmari zone due to an increase of shale and marl layers and due to less break ablity has a less distribution of fractures. The result show that there are a good conformity existed between the results of inscribed circle analysis, image log, core data, curvature and the presence of fractures in Marun anticline. The data indicate that highest density of fracture density concentrates in the southern limb in the central region of anticline and also in the north limb in the northeast region of the anticline. So, finally using these parameters, it is recommended that further development and production wells be drilled in the north eastern part of the oil filed as well as center part of southern flank of the anticline.

  4. Determination of density pattern of fracture in Asmari Formation in Marun oilfield

    Directory of Open Access Journals (Sweden)

    Mehdi Khoshnodkia

    2015-04-01

    Full Text Available Marun oilfield is located in the middle part of Dezful Embayment and is situated along the Aghajari, Ahvaz and Ramin anticline. Given the important role of fracture characteristics for improving production, so the aim of this research is to investigate the density pattern of fracture in Asmari formation in Marun oilfield. For this purpose, results of image log, core data, graphic well log, methods of inscribed circle analysis and curvature changes geometry of anticline were analyzed. Asmari formation is the main reservoir rock in Marun oilfield that divided into five zones. Limestone and dolomite are the main lithology of zones 1, 2 and 3 which has a high density of fractures (especially in zones with 90% dolomite. Also there is less fracture density (micro fracture in the 4 and 5 Asmari zone due to an increase of shale and marl layers and due to less break ablity has a less distribution of fractures. The result show that there are a good conformity existed between the results of inscribed circle analysis, image log, core data, curvature and the presence of fractures in Marun anticline. The data indicate that highest density of fracture density concentrates in the southern limb in the central region of anticline and also in the north limb in the northeast region of the anticline. So, finally using these parameters, it is recommended that further development and production wells be drilled in the north eastern part of the oil filed as well as center part of southern flank of the anticline.

  5. The analysis of scaling mechanism for water-injection pipe columns in the Daqing Oilfield

    Directory of Open Access Journals (Sweden)

    Guolin Jing

    2017-02-01

    Full Text Available Although water-injection in mature reservoirs is a promising low-cost method of enhanced oil recovery (EOR, in the process of development in the oilfield, scale has been produced in water-injection pipe columns. The ability to prevent and control the deposition of scale is critical to the efficient recovery of crude oil from hard environments, as part of the broader discipline of “flow assurance” in the petroleum industry. To this end laboratory-scale deposition tests have been useful to understand scale deposition mechanism. The process, mechanism and the main type of the scale in water-injection pipe columns of the fifth plant of the Daqing Oilfield were analyzed. The effect of temperature on the possibility of carbonate calcium formation on oil recovery was investigated experimentally. One of the scale samples was characterized by electron spectroscopy and the results of the element analysis were investigated. Moreover, the precautionary and control measures of scaling in oilfield pipe column systems are proposed.

  6. Estimate of Hot Dry Rock Geothermal Resource in Daqing Oilfield, Northeast China

    Directory of Open Access Journals (Sweden)

    Guangzheng Jiang

    2016-10-01

    Full Text Available Development and utilization of deep geothermal resources, especially a hot dry rock (HDR geothermal resource, is beneficial for both economic and environmental consideration in oilfields. This study used data from multiple sources to assess the geothermal energy resource in the Daqing Oilfield. The temperature logs in boreholes (both shallow water wells and deep boreholes and the drilling stem test temperature were used to create isothermal maps in depths. Upon the temperature field and thermophysical parameters of strata, the heat content was calculated by 1 km × 1 km × 0.1 km cells. The result shows that in the southeastern part of Daqing Oilfield, the temperature can reach 150 °C at a depth of 3 km. The heat content within 3–5 km is 24.28 × 1021 J, wherein 68.2% exceeded 150 °C. If the recovery factor was given by 2% and the lower limit of temperature was set to be 150 °C, the most conservative estimate for recoverable HDR geothermal resource was 0.33 × 1021 J. The uncertainties of the estimation are mainly contributed to by the temperature extrapolation and the physical parameter selections.

  7. Detailed study of seismic wave attenuation from four oilfields in Abu Dhabi, United Arab Emirates

    Science.gov (United States)

    Bouchaala, F.; Ali, M. Y.; Matsushima, J.

    2018-02-01

    In the present study, we provide a detailed study of seismic wave attenuation obtained from four oilfields. The reservoir zones of these oilfields are complicated due to complex fracture networks, the presence of tar mat and high heterogeneity of carbonate rocks of which the subsurface of Abu Dhabi is mainly composed. These complexities decrease signal-to-noise ratio and make attenuation estimation difficult. We obtained high-resolution attenuation profiles from vertical seismic profiling (VSP) and sonic waveform data. The VSP data were recorded in all four oilfields and the sonic data were acquired in the reservoir zones of oilfields I and IV. We found that the VSP scattering attenuation ({Q}{{S}{{c}}{{a}}{{t}}}-1) varies from ‑0.080 to 0.180 over a depth range of 400–3500 m. We attributed this significant scattering to the high heterogeneity of carbonate rocks. The scattering profiles seem to be sensitive to fractures, lithology heterogeneity and tar mat, but their effect is superimposed. The VSP intrinsic attenuation varies from ‑0.15 to 0.246 with high variation within each formation. Since intrinsic attenuation is closely related to fluids, we assumed that this variation is due to the non-uniform distribution of fluids caused by the complex porosity network of the subsurface. The sonic monopole attenuation ({Q}{{M}{{f}}}-1) in the reservoir zones ranges between 0.033–0.094 and dipole inline attenuation ({Q}{{I}{{n}}{{l}}}-1) ranges from 0.040–0.138. The sonic attenuation appears to be sensitive to the presence of fluid and type of fractures, where it shows high attenuation for open fractures and low attenuation for resistive fractures. The zones with high clay content display high sonic intrinsic attenuation in the reservoir of oilfield II. We explain this by the frictional movement between the clay and carbonates due to the elasticity contrast of these two materials. Therefore, the solid grain friction may be the dominant attenuation mechanism in

  8. Deep-water oilfield development cost analysis and forecasting —— Take gulf of mexico for example

    Science.gov (United States)

    Shi, Mingyu; Wang, Jianjun; Yi, Chenggao; Bai, Jianhui; Wang, Jing

    2017-11-01

    Gulf of Mexico (GoM) is the earliest offshore oilfield which has ever been developed. It tends to breed increasingly value of efficient, secure and cheap key technology of deep-water development. Thus, the analyze of development expenditure in this area is significantly important the evaluation concept of deep-water oilfield all over the world. This article emphasizes on deep-water development concept and EPC contract value in GoM in recent 10 years in case of comparison and selection to the economic efficiency. Besides, the QUETOR has been put into use in this research processes the largest upstream cost database to simulate and calculate the calculating examples’ expenditure. By analyzing and forecasting the deep-water oilfield development expenditure, this article explores the relevance between expenditure index and oil price.

  9. Study on fine geological modelling of the fluvial sandstone reservoir in Daqing oilfield

    Energy Technology Data Exchange (ETDEWEB)

    Zhoa Han-Qing [Daqing Research Institute, Helongjiang (China)

    1997-08-01

    These paper aims at developing a method for fine reservoir description in maturing oilfields by using close spaced well logging data. The main productive reservoirs in Daqing oilfield is a set of large fluvial-deltaic deposits in the Songliao Lake Basin, characterized by multi-layers and serious heterogeneities. Various fluvial channel sandstone reservoirs cover a fairly important proportion of reserves. After a long period of water flooding, most of them have turned into high water cut layers, but there are considerable residual reserves within them, which are difficult to find and tap. Making fine reservoir description and developing sound a geological model is essential for tapping residual oil and enhancing oil recovery. The principal reason for relative lower precision of predicting model developed by using geostatistics is incomplete recognition of complex distribution of fluvial reservoirs and their internal architecture`s. Tasking advantage of limited outcrop data from other regions (suppose no outcrop data available in oilfield) can only provide the knowledge of subtle changing of reservoir parameters and internal architecture. For the specific geometry distribution and internal architecture of subsurface reservoirs (such as in produced regions) can be gained only from continuous infilling logging well data available from studied areas. For developing a geological model, we think the first important thing is to characterize sandbodies geometries and their general architecture`s, which are the framework of models, and then the slight changing of interwell parameters and internal architecture`s, which are the contents and cells of the model. An excellent model should possess both of them, but the geometry is the key to model, because it controls the contents and cells distribution within a model.

  10. Chemical fractionation of radium-226 in NORM contaminated soil from oilfields.

    Science.gov (United States)

    Al Abdullah, Jamal; Al-Masri, Mohammad Said; Amin, Yusr; Awad, Ibrahim; Sheaib, Zuhair

    2016-12-01

    Contamination of soil with (226)Ra is a common problem in the oilfields, leading to costly remediation and disposal programmes. The present study focuses on the chemical fractionation and mobility of (226)Ra in contaminated soils collected from an oilfield using a three-step sequential extraction procedure (BCR). The total activity concentrations of (226)Ra in contaminated soils were measured and found to be in the range from 1030 ± 90 to 7780 ± 530 Bq kg(-1), with a mean activity concentration of 2840 ± 1840 Bq kg(-1). The correlation between the total concentration of (226)Ra and soil properties, mainly pH, LOI, Corg, clay and Ca, was investigated using the principal component analysis method (PCA). The chemical fractionation of (226)Ra was studied using the sequential extraction method (BCR). The highest fraction of (226)Ra (27-65%) was found to be in the acid-reducible fraction, which suggests that (226)Ra is mainly bound to FeMn oxides. The BCR method showed that high percentages of (226)Ra were found to be in mobile soil phases (between 45 and 99%). Consequently, groundwater contamination could occur due to the remobilization of (226)Ra from soils under normal environmental conditions. However, the obtained results could be useful to reduce the volume of NORM wastes generated from the oilfields and decision-making process for final treatment and disposal of NORM-contaminated soil. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Signature alkane ratios and hydrocarbon emissions estimates for western Kern county oilfields

    Science.gov (United States)

    Bates, K. H.; Hartt, G.; Blake, D. R.

    2012-12-01

    This study reports atmospheric indicators and volatile organic compound (VOC) emissions estimates of Californian fossil fuel infrastructure as observed by NASA's Student Airborne Research Program (SARP). Oil and gas drilling constitute a major source of VOCs in California, including methane, a potent greenhouse gas, and larger hydrocarbons, which affect air quality and ozone formation. Whole air samples were collected at ground sites (34 samples, July 3-5) and on five SARP research flights (303 samples, June 25-27) in the Los Angeles Basin and California's Central Valley, and were analyzed at UC Irvine for 85 VOCs at part-per-trillion precision. Ground and air samples collected near western Kern county oilfields exhibited many signature VOC ratios and significantly elevated hydrocarbon concentrations. Ratios of i-pentane to n-pentane presented the strongest indicator of fossil fuel infrastructure; background i-/n-pentane ratios dropped by 65% for samples near seeps, wells, and refineries. This ratio proved a robust indicator throughout southern California for SARP whole air samples from 2009-2012 and additional ground samples collected by the Blake lab in 2012 near the western Kern county oilfields. Using this ratio to identify the geographic extent of oil infrastructure emissions, a simple box model was constructed to estimate the yearly VOC emissions of the western Kern county oilfields. Preliminary results suggest an annual non-methane hydrocarbon output from the 450 km2 oil field of 29.1±1.9 Gg and methane emissions of 103±49 Gg. The results of this simple model were consistent across three sampling periods in 2012, suggesting a robust estimate.

  12. Prediction of calcium carbonate precipitation in oilfields based on a fuzzy solubility model

    Energy Technology Data Exchange (ETDEWEB)

    Khatami, H.R.; Ranjbar, M. [S.B. Kerman Univ. (Iran). Dept. of Mining Engineering; Schaffie, M. [S.B. Kerman Univ. (Iran). Dept. of Chemical Engineering; Emadi, M.A. [National Iranian Oil Company, Tehran (Iran)

    2008-06-15

    The ability of fuzzy logic in treating uncertainty and imprecision is used to simulate the influence of temperature and partial pressure of carbon dioxide on the solubility of calcium carbonate. The scaling tendency for calcium carbonate due to change in physical conditions of four Iranian oilfields is determined by means of the developed fuzzy solubility model. Calculation of saturation index for the fields shows a considerable risk of calcium carbonate deposition. A fuzzy truth value graph is also proposed in order to provide an interpretation for the obtained saturation index values and to recommend suitable action for scale prevention and inhibition. (orig.)

  13. Application of oil-field well log interpretation techniques to the Cerro Prieto Geothermal Field

    Energy Technology Data Exchange (ETDEWEB)

    Ershaghi, I.; Phillips, L.B.; Dougherty, E.L.; Handy, L.L.

    1979-10-01

    An example is presented of the application of oil-field techniques to the Cerro Prieto Field, Mexico. The lithology in this field (sand-shale lithology) is relatively similar to oil-field systems. The study was undertaken as a part of the first series of case studies supported by the Geothermal Log Interpretation Program (GLIP) of the US Department of Energy. The suites of logs for individual wells were far from complete. This was partly because of adverse borehole conditions but mostly because of unavailability of high-temperature tools. The most complete set of logs was a combination of Dual Induction Laterolog, Compensated Formation Density Gamma Ray, Compensated Neutron Log, and Saraband. Temperature data about the wells were sketchy, and the logs had been run under pre-cooled mud condition. A system of interpretation consisting of a combination of graphic and numerical studies was used to study the logs. From graphical studies, evidence of hydrothermal alteration may be established from the trend analysis of SP (self potential) and ILD (deep induction log). Furthermore, the cross plot techniques using data from density and neutron logs may help in establishing compaction as well as rock density profile with depth. In the numerical method, R/sub wa/ values from three different resistivity logs were computed and brought into agreement. From this approach, values of formation temperature and mud filtrate resistivity effective at the time of logging were established.

  14. Isolation and Characterization of Oil-Degrading Bacteria from One of South Sumatera’s Oilfield

    Science.gov (United States)

    Purwasena, I. A.; Astuti, D. I.; Fatmawati, R.; Afinanisa, Q.

    2018-01-01

    Microbial Enhanced Oil Recovery (MEOR) is a tertiary oil recovery method that utilizes microbes to enhance oil production. This research was focused on the isolation and characterization of indigenous bacteria from a South Sumatra’s oilfield which were able to degrade heavy crude oil and decrease oil viscosity. The total of 33 colonies were successfully isolated based on sequential isolation method and screened based on oil degradation activity and SARA analysis. Isolate G3, G7, and N6 were choosen as the best candidate as they were able to reduce oil viscosity up to 22,67%; 23,14%; and 24,36% respectively. Based on 16S rRNA analysis, isolate G3 which was able to degrade aromatic fraction (38,27%) and resin (29,26%) was identified as Pseudoxhantomonas taiwanensis. Isolate G7 which degraded aromatic fraction (61,14%) was identified as Brevibacillus agri while N6 which degraded asphaltene fraction (51.76%) was identified as Bacillus subtilis. In addition, the change in nalkana fraction (C11 – C28) abundance relative to phytan showed that all of the bacterial isolates were able to change those fractions of crude oil. This study showed that three bacterial species isolated from South Sumatran Oilfield were able to degrade heavier fraction of crude oil and reduce its viscosity. This result suggests that those bacteria are highly potential to be applied for MEOR technology.

  15. Microbial community dynamics in Baolige oilfield during MEOR treatment, revealed by Illumina MiSeq sequencing.

    Science.gov (United States)

    You, Jing; Wu, Gang; Ren, Fuping; Chang, Qi; Yu, Bo; Xue, Yanfen; Mu, Bozhong

    2015-10-24

    This study was carried out to understand microbial diversity and function in the microbial enhanced oil recovery (MEOR) process and to assess the impact of MEOR treatment on the microbial community in an oil reservoir. The Illumina MiSeq-based method was used to investigate the structure and dynamics of the microbial community in a MEOR-treated block of the Baolige oilfield, China. The results showed that microbial diversity was high and that 23 phyla occurred in the analyzed samples. Proteobacteria, Firmicutes, Bacteroidetes, Thermotogae, and Euryarchaeota were present in relatively high abundance in all analyzed samples. Injection of bacteria and nutrients resulted in interesting changes in the composition of the microbial community. During MEOR treatment, the community was dominated by the known hydrocarbon-utilizing genera Pseudomonas and Acinetobacter. After the treatment, the two genera decreased in abundance over time while Methanobacteriaceae, as well as known syntrophic genera such as Syntrophomonas, Pelotomaculum, Desulfotomaculum, and Thermacetogenium gradually increased. The change in dominant microbial populations indicated the presence of a succession of microbial communities over time, and the hydrocarbon degradation and syntrophic oxidation of acetate and propionate to methane in the MEOR-treated oilfield. This work contributes to a better understanding of microbial processes in oil reservoirs and helps to optimize MEOR technology.

  16. Effects of produced waters at oilfield production sites on the Osage Indian Reservation, northeastern Oklahoma

    Science.gov (United States)

    Otton, James K.; Asher-Bolinder, Sigrid; Owen, Douglass E.; Hall, Laurel

    1997-01-01

    The authors conducted limited site surveys in the Wildhorse and Burbank oilfields on the Osage Indian Reservation, northeastern Oklahoma. The purpose was to document salt scarring, erosion, and soil and water salinization, to survey for radioactivity in oilfield equipment, and to determine if trace elements and naturally occurring radioactive materials (NORM) were present in soils affected by oilfield solid waste and produced waters. These surveys were also designed to see if field gamma spectrometry and field soil conductivity measurements were useful in screening for NORM contamination and soil salinity at these sites. Visits to oilfield production sites in the Wildhorse field in June of 1995 and 1996 confirmed the presence of substantial salt scarring, soil salinization, and slight to locally severe erosion. Levels of radioactivity on some oil field equipment, soils, and road surfaces exceed proposed state standards. Radium activities in soils affected by tank sludge and produced waters also locally exceed proposed state standards. Laboratory analyses of samples from two sites show moderate levels of copper, lead, and zinc in brine-affected soils and pipe scale. Several sites showed detectable levels of bromine and iodine, suggesting that these trace elements may be present in sufficient quantity to inhibit plant growth. Surface waters in streams at two sampled sites exceed total dissolved solid limits for drinking waters. At one site in the Wildhorse field, an EM survey showed that saline soils in the upper 6m extend from a surface salt scar downvalley about 150 m. (Photo [95k]: Dead oak trees and partly revegetated salt scar at Site OS95-2 in the Wildhorse field, Osage County, Oklahoma.) In the Burbank field, limited salt scarring and slight erosion occurs in soils at some sites and low to moderate levels of radioactivity were observed in oil field equipment at some sites. The levels of radioactivity and radium observed in some soils and equipment at these

  17. 77 FR 33098 - Hours of Service of Drivers of Commercial Motor Vehicles; Regulatory Guidance for Oilfield Exception

    Science.gov (United States)

    2012-06-05

    ...'' and to ``perform other acts the Secretary considers appropriate'' . The Administrator of FMCSA has... years ago, are not readily available. In the August 15, 1962, Federal Register notice, the oilfield... time exception.'' Issued on: May 30, 2012. Anne S. Ferro, Administrator. BILLING CODE 4910-EX-P ...

  18. Non-Newtonian Flow Characteristics of Heavy Oil in the Bohai Bay Oilfield: Experimental and Simulation Studies

    Directory of Open Access Journals (Sweden)

    Xiankang Xin

    2017-10-01

    Full Text Available In this paper, physical experiments and numerical simulations were applied to systematically investigate the non-Newtonian flow characteristics of heavy oil in porous media. Rheological experiments were carried out to determine the rheology of heavy oil. Threshold pressure gradient (TPG measurement experiments performed by a new micro-flow method and flow experiments were conducted to study the effect of viscosity, permeability and mobility on the flow characteristics of heavy oil. An in-house developed novel simulator considering the non-Newtonian flow was designed based on the experimental investigations. The results from the physical experiments indicated that heavy oil was a Bingham fluid with non-Newtonian flow characteristics, and its viscosity-temperature relationship conformed to the Arrhenius equation. Its viscosity decreased with an increase in temperature and a decrease in asphaltene content. The TPG measurement experiments was impacted by the flow rate, and its critical flow rate was 0.003 mL/min. The TPG decreased as the viscosity decreased or the permeability increased and had a power-law relationship with mobility. In addition, the critical viscosity had a range of 42–54 mPa∙s, above which the TPG existed for a given permeability. The validation of the designed simulator was positive and acceptable when compared to the simulation results run in ECLIPSE V2013.1 and Computer Modelling Group (CMG V2012 software as well as when compared to the results obtained during physical experiments. The difference between 0.0005 and 0.0750 MPa/m in the TPG showed a decrease of 11.55% in the oil recovery based on the simulation results, which demonstrated the largely adverse impact the TPG had on heavy oil production.

  19. Failure life determination of oilfield elastomer seals in sour gas/dimethyl disulfide environments

    Energy Technology Data Exchange (ETDEWEB)

    Kennelley, K.J.; Abrams, P.I. (Exxon Production Research Co., Houston, TX (US)); Vicic, J.C. (FMC Corp., Central Engineering Labs., Santa Clara, CA (US)); Cain, D. (FMC Corp., Wellhead Equipment, Houston, TX (US))

    1989-01-01

    Previous screening tests of various oilfield elastomers in sour gas/dimethyl disulfide environments indicated that hydrogenated nitrile (HNBR), tetrafluoroethylene-propylene (TFE/P), ethylene-propylene-diene (EPDM), and perfluorinated rubber (FFKM) elastomers may perform satisfactorily in these environments. This paper describes subsequent failure life tests conducted with the subject elastomers in the sour gas/dimethyl disulfide test environment at several elevated temperatures (> 135{degrees}C). The materials were tested in the form of O-rings (size 214), which were used to seal an autoclave containing the test environment at 14 MPa gas pressure. The results were used to extrapolate time to failure at a common reference temperature of 135{degrees}C. The performance of EPDM and HNBR in the sour gas/dimethyl disulfide mixture substantially exceeded a projected 20-year service life at 135{degrees}C, while FFKM and TFE/P did not.

  20. Standard guide for evaluating and qualifying oilfield and refinery corrosion inhibitors in the laboratory

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 This guide covers some generally accepted laboratory methodologies that are used for evaluating corrosion inhibitors for oilfield and refinery applications in well defined flow conditions. 1.2 This guide does not cover detailed calculations and methods, but rather covers a range of approaches which have found application in inhibitor evaluation. 1.3 Only those methodologies that have found wide acceptance in inhibitor evaluation are considered in this guide. 1.4 This guide is intended to assist in the selection of methodologies that can be used for evaluating corrosion inhibitors. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory requirements prior to use.

  1. Research on high speed drilling technology and economic integration evaluation in Oilfield

    Science.gov (United States)

    Wang, Kun; Ni, Hongjian; Cheng, Na; Song, Jingbo

    2018-01-01

    The carbonate reservoir in the oilfield mainly formed in Ordovician System and Carboniferous System. The geology here is very complicated, with high heterogeneity. It gets much more difficult to control the well deflection in Permian system so that high accident ratio could be expected. The buried depth of the reservoir is large, normally 4600-6600m deep. The temperature of the layer is higher than 132 and the pressure is greater than 62MPa. The reservoir is with a high fluid properties, mainly including thin oil, heavy oil, condensate oil, gas and so on; the ground is very hard to drill, so we can foresee low drilling speed, long drilling period and high drilling cost, which will surely restrict the employing progress of the reservoir.

  2. Research on CO2 Quality Pipeline Transportation Based on Yanchang Oilfield CCUS

    Directory of Open Access Journals (Sweden)

    Yang Yongchao

    2017-01-01

    Full Text Available CO2 capture,utilization and storage (CCUS is now recognized as an important technology in the global scope of CO2 emission reduction, pipeline transportation is the main center to connect the capture point and the use storage point, the first issue to CO2 pipeline transportation is to solve CO2 source quality research. Yanchang Oilfield has the advantages of CCUS, its coal chemical capture of CO2 contains different impurities. In the CO2 pipeline transportation, the impurity content in CO2 is based on its end use and the actual situation of pipeline. The impurities will affect the efficiency of CO2-EOR, the choice of CO2 state equation, the changes of CO2 phase diagram and the capacity of pipeline transportation.

  3. Sequence Stratigraphy of lower zones of Asmari Formation in Marun Oilfield by using of microfacies analysis, isolith maps and γ- Ray log

    OpenAIRE

    Jalil Jafari; Mohammad Khanehbad; Asadollah Mahboubi; Ahmad Mirmarghabi; Reza Moussavi harami; Shahram Avarjani

    2015-01-01

    The Oligo- Miocene Asmari Formation is one of the most important reservoir units of the Marun Oilfield in Dezful Embayment SW Iran, deposited in Zagros foreland basin. The goal of this study is to interpret depositional environment and sequence stratigraphy of lower zones of the Asmari Formation in Well No.281, 342 and 312in Marun Oilfield based on changes in the shape of γ- Ray, isolith maps and microfacies properties. Accordingly, identification of 9 carbonate microfacies and 2 siliciclas...

  4. Sequence Stratigraphy of lower zones of Asmari Formation in Marun Oilfield by using of microfacies analysis, isolith maps and γ- Ray log

    OpenAIRE

    Ahmad Mirmarghabi; Reza Moussavi harami; Asadollah Mahboubi; Mohammad Khanehbad; Jalil Jafari; Shahram Avarjani

    2015-01-01

    The Oligo- Miocene Asmari Formation is one of the most important reservoir units of the Marun Oilfield in Dezful Embayment SW Iran, deposited in Zagros foreland basin. The goal of this study is to interpret depositional environment and sequence stratigraphy of lower zones of the Asmari Formation in Well No.281, 342 and 312in Marun Oilfield based on changes in the shape of γ- Ray, isolith maps and microfacies properties. Accordingly, identification of 9 carbonate microfacies and 2 siliciclast...

  5. Effects of untreated and treated oilfield-produced water on seed germination, seedling development, and biomass production of sunflower (Helianthus annuus L.).

    Science.gov (United States)

    da Costa Marques, Mônica Regina; de Souza, Paulo Sérgio Alves; Rigo, Michelle Machado; Cerqueira, Alexandre Andrade; de Paiva, Julieta L; Merçon, Fábio; Perez, Daniel Vidal

    2015-10-01

    This study aims to evaluate possible toxic effects of oil and other contaminants from oilfield-produced water from oil exploration and production, on seed germination, and seedling development of sunflower (Helianthus annuus L.). In comparison, as treated by electroflocculation, oilfield-produced water, with lower oil and organic matter content, was also used. Electroflocculation treatment of oilfield-produced water achieved significant removals of chemical oxygen demand (COD) (94 %), oil and grease (O&G) (96 %), color (97 %), and turbidity (99 %). Different O&G, COD, and salt levels of untreated and treated oilfield-produced water did not influence germination process and seedling biomass production. Normal seedlings percentage and vigor tended to decrease more intensely in O&G and COD levels, higher than 337.5 mg L(-1) and 1321 mg O2 L(-1), respectively, using untreated oilfield-produced water. These results indicate that this industrial effluent must be treated, in order to not affect adversely seedling development. This way, electroflocculation treatment appears as an interesting alternative to removing oil and soluble organic matter in excess from oilfield-produced water improving sunflower's seedling development and providing a friendly environmental destination for this wastewater, reducing its potential to harm water resources, soil, and biota.

  6. FORECASTING THE PERFORMANCE OF AN OIL FIELD, COMPARISON OF VARIOUS USED METHODS: THE CASE OF SHUANGHE OILFIELD, CHINA

    Directory of Open Access Journals (Sweden)

    Theoneste Nzayisenga

    2014-01-01

    Full Text Available While being the dominant source of energy, oil has also brought affluence and power to different societies. Energy produced from oil is fundamental to all parts of society. In the foreseeable future, the majority of energy will still come from oil production. Consequently, reliable methods for forecasting that production are crucial. Petroleum engineers have searched for simple but reliable way to predict oil production for a long time. Many methods have been developed in the latest decades and one common practice is decline curve analysis. Prediction of future production of petroleum wells is important for cost-effective operations of the petroleum industry. This work presents a comparative analysis of methods used to predict the performance of Shuanghe oilfield, China. Using decline curve analysis including three different methods: Arps empirical methods, LL-model and simplified model and the new simplified model, LL-Model, to crosscheck Arps exponential decline model prediction results. The results showed by the comparative analysis of predictions calculated proved LL-model to be the best predictor for Shuanghe oilfield since it takes into account more parameters than the old models used in this work. However, the subsurface information or parameters of the reservoir used in LL-model may not be available every time, therefore Arps models may apply as defined. In Shuanghe oilfield calculated average geological reserves N was estimated at 9449.41 ×104 tons, the average recoverable reserves NR were estimated to 4274.61×104 tons while the water cut was 97% and the water cut predicted by LL-model was 96.7%; not far from water flooding curves value. The exponential decline model showed recoverable reserves NR estimated around 4685.88×104 tons of oil while the decline phase of total development was estimated around 34 years which means that if the actual production conditions remain unchanged, Shuanghe oilfield would continue producing for

  7. Monitoring Oilfield Operations and GHG Emissions Sources Using Object-based Image Analysis of High Resolution Spatial Imagery

    Science.gov (United States)

    Englander, J. G.; Brodrick, P. G.; Brandt, A. R.

    2015-12-01

    Fugitive emissions from oil and gas extraction have become a greater concern with the recent increases in development of shale hydrocarbon resources. There are significant gaps in the tools and research used to estimate fugitive emissions from oil and gas extraction. Two approaches exist for quantifying these emissions: atmospheric (or 'top down') studies, which measure methane fluxes remotely, or inventory-based ('bottom up') studies, which aggregate leakage rates on an equipment-specific basis. Bottom-up studies require counting or estimating how many devices might be leaking (called an 'activity count'), as well as how much each device might leak on average (an 'emissions factor'). In a real-world inventory, there is uncertainty in both activity counts and emissions factors. Even at the well level there are significant disagreements in data reporting. For example, some prior studies noted a ~5x difference in the number of reported well completions in the United States between EPA and private data sources. The purpose of this work is to address activity count uncertainty by using machine learning algorithms to classify oilfield surface facilities using high-resolution spatial imagery. This method can help estimate venting and fugitive emissions sources from regions where reporting of oilfield equipment is incomplete or non-existent. This work will utilize high resolution satellite imagery to count well pads in the Bakken oil field of North Dakota. This initial study examines an area of ~2,000 km2 with ~1000 well pads. We compare different machine learning classification techniques, and explore the impact of training set size, input variables, and image segmentation settings to develop efficient and robust techniques identifying well pads. We discuss the tradeoffs inherent to different classification algorithms, and determine the optimal algorithms for oilfield feature detection. In the future, the results of this work will be leveraged to be provide activity

  8. Forward Stagewise Naive Bayes

    OpenAIRE

    Vidaurre Henche, Diego; Bielza, Concha; Larrañaga Múgica, Pedro

    2012-01-01

    The naïve Bayes approach is a simple but often satisfactory method for supervised classification. In this paper, we focus on the naïve Bayes model and propose the application of regularization techniques to learn a naïve Bayes classifier. The main contribution of the paper is a stagewise version of the selective naïve Bayes, which can be considered a regularized version of the naïve Bayes model. We call it forward stagewise naïve Bayes. For comparison’s sake, we also introduce an explicitly r...

  9. Removal Capacities of Polycyclic Aromatic Hydrocarbons (PAHs by a Newly Isolated Strain from Oilfield Produced Water

    Directory of Open Access Journals (Sweden)

    Yi-Bin Qi

    2017-02-01

    Full Text Available The polycyclic aromatic hydrocarbon (PAH-degrading strain Q8 was isolated from oilfield produced water. According to the analysis of a biochemical test, 16S rRNA gene, house-keeping genes and DNA–DNA hybridization, strain Q8 was assigned to a novel species of the genus Gordonia. The strain could not only grow in mineral salt medium (MM and utilize naphthalene and pyrene as its sole carbon source, but also degraded mixed naphthalene, phenanthrene, anthracene and pyrene. The degradation ratio of these four PAHs reached 100%, 95.4%, 73.8% and 53.4% respectively after being degraded by Q8 for seven days. A comparative experiment found that the PAHs degradation efficiency of Q8 is higher than that of Gordonia alkaliphila and Gordonia paraffinivorans, which have the capacities to remove PAHs. Fourier transform infrared spectra, saturate, aromatic, resin and asphaltene (SARA and gas chromatography–mass spectrometry (GC–MS analysis of crude oil degraded by Q8 were also studied. The results showed that Q8 could utilize n-alkanes and PAHs in crude oil. The relative proportions of the naphthalene series, phenanthrene series, thiophene series, fluorene series, chrysene series, C21-triaromatic steroid, pyrene, and benz(apyrene were reduced after being degraded by Q8. Gordonia sp. nov. Q8 had the capacity to remediate water and soil environments contaminated by PAHs or crude oil, and provided a feasible way for the bioremediation of PAHs and oil pollution.

  10. [Petroleum pollution and the microbial community structure in the soil of Shengli Oilfield].

    Science.gov (United States)

    Liu, Jian; Song, Xue-Ying; Sun, Rui-Lian; Xie, Fu-Ju; Wang, Ren-Qing; Wang, Wen-Xing

    2014-03-01

    Soils around a new oil well (2011- ) and an old oil well (1966-2003) were sampled to investigate the characteristics of petroleum pollution in the oilfield. The structure of soil microbial community was analyzed by PCR-DGGE and clone sequencing techniques. Results showed that the soils around the two oil wells were generally contaminated with petroleum, and the concentrations of total petroleum hydrocarbons mostly exceeded the threshold of the environmental quality standards of soil (500 mg x kg(-1)). The total petroleum hydrocarbons concentration of the polluted soil was significantly positively correlated with the contents of organic carbon, total nitrogen and available potassium, respectively. The microbial diversity index in the soil around the old oil well decreased with the increasing total petroleum hydrocarbons concentration, however, it was reversed for the soil around the new oil well. Sequence analysis of the prominent bands in DGGE profiles showed that some dominant species existed in the petroleum-contaminated soils around the oil wells and mostly were oil-associated and hydrocarbon degrading bacteria, including Microbacterium, Streptomyces, Dietzia, Flavobacterium, alpha-Proteobacteria, and gamma-Proteobacteria.

  11. Studies on a Foam System of Ultralow Interfacial Tension Applied in Daqing Oilfield after Polymer Flooding

    Directory of Open Access Journals (Sweden)

    Hong-sheng Liu

    2013-01-01

    Full Text Available In order to study the effects of oil displacement by a foam system of ultralow interfacial tension, the interfacial activities and foam properties of a nonionic gemini surfactant (DWS were investigated under Daqing Oilfield reservoir conditions. Injection methods and alternate cycle of the foam system were discussed here on the basis of results from core flow experiments. It was obtained that the surface tension of DWS was approximately 25 mN/m, and ultralow interfacial tension was reached between oil and DWS with a surfactant concentration between 0.05wt% and 0.4wt%. The binary system showed splendid foam performances, and the preferential surfactant concentration was 0.3wt% with a polymer concentration of 0.2wt%. When gas and liquid were injected simultaneously, flow control capability of the foam reached its peak at the gas-liquid ratio of 3 : 1. Enhanced oil recovery factor of the binary foam system exceeded 10% in a parallel natural cores displacement after polymer flooding.

  12. Waste drilling-fluid-utilising microorganisms in a tropical mangrove swamp oilfield location

    Energy Technology Data Exchange (ETDEWEB)

    Benka-Coker, M.O.; Olumagin, A. [Benin Univ. (Nigeria). Dept. of Microbiology

    1995-12-31

    Waste drilling-fluid-utilising microorganisms were isolated from drilling-mud cuttings, soil and creek water from a mangrove swamp oilfield location in the Delta area of Nigeria using waste drilling-fluid as the substrate. Eighteen bacterial isolates obtained were identified as species of Staphylococcus, Acinetobacter, Alcaligenes, Serratia, Clostridium, Enterobacter, Klebsiella, Nocardia, Bacillus, Actinomyces, Micrococcus and Pseudomonas, while the genera of fungi isolated were Penicillium, Cladosporium and Fusarium. Even though drilling-fluid-utilising genera were in higher numbers in the soil than in the two other sources examined, the percentages of the total heterotrophic bacteria that utilised waste drilling-fluid were 6.02 in the drilling-mud cuttings, 0.83 in creek water and 0.42 in soil. The screen tests for biodegradation potential of the bacterial isolates showed that, even though all the isolates were able to degrade and utilise the waste fluid for growth, species of Alcaligenes and Micrococcus were more active degraders of the waste. The significance of the results in environmental management in oil-producing areas of Nigeria is discussed. (Author)

  13. Treatment of oilfield fracturing wastewater by a sequential combination of flocculation, Fenton oxidation and SBR process.

    Science.gov (United States)

    Yang, Jian; Hong, Liang; Liu, Yan-Hong; Guo, Jian-Wei; Lin, Li-Fei

    2014-01-01

    In this study, a combined process was developed that included flocculation, Fenton oxidation and sequencing batch reactor (SBR) to treat oilfield fracturing wastewater (FW). Flocculation and Fenton oxidation were applied to reduce chemical oxygen demand (COD) organic load and to enhance biodegradability, respectively. For flocculation, the optimum conditions were: polymeric aluminium chloride dosage, 40 mg/L; polyacrylamide dosage, 4 mg/L; dilution ratio, 1:2 and stirring time, 30 min. For Fenton oxidation, a total reaction time of 60 min, a H₂O₂dosage of 2 m mol/L, with a [H₂O₂]/[FeSO₄] ratio of 2 were selected to achieve optimum oxidation. Under these optimum flocculation and Fenton oxidation conditions, the COD removal efficiency was found to be 76.6%. Following pretreatment with flocculation and Fenton oxidation, the FW was further remediated using a SBR. Results show that COD was reduced to 92 mg/L, and the overall water quality of the final effluent could meet the class I national wastewater discharge standard of petrochemical industry of China.

  14. Mechanism evaluation of carbon dioxide miscible flooding : Caoshe oilfield case study

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Y.; Du, Z.; Sun, L. [State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu (China); Southwest Petroleum Univ., Chengdu (China); Yu, K.; Liu, W.; Chen, Z. [SINOPEC (China). East China Oil Field Branch

    2009-07-01

    This paper investigated the mechanisms of a carbon dioxide (CO{sub 2}) miscible flooding project at an oilfield in China. Laboratory tests included pressure-volume-temperature (PVT), CO{sub 2} injection swelling, and slim tube tests. Results of the experimental tests were then used to construct an equations-of-state (EOS) compositional model with a 1D and 2D profile of an injector-production well group. Changes in fluid composition and the viscosity and density of the oil and vapor phases were characterized as well as the interfacial tension between oil and gas along the grids during the CO{sub 2} injection process. The effect of gas volume and injection pressure on fluid properties was also investigated. the study showed that the minimum miscibility pressure (MMP) of the project is 30 MPa. The model content of the CO{sub 2} in oil phase can be reacted at a formation pressure of 32 MPa with a 70 per cent oil phase. A continuous CO{sub 2} injection method with formation pressures above the MMP was recommended for the field. 10 refs., 3 tabs., 22 figs.

  15. Evaluation of membranes for the treatment of oilfield-produced water

    Directory of Open Access Journals (Sweden)

    Silvio Edegar Weschenfelder

    2015-04-01

    Full Text Available Large quantities of water are generated during oil extraction. Reinjection of this effluent is frequently the most suitable option for environmental considerations. For this purpose, the water produced must have characteristics that will prevent the plugging of the reservoir rocks, i.e., suspended solids and oil and grease content must be lower than 5 mg L-1. This work evaluated the performance of membranes for water treatment, based upon long-term experiments with real effluent, evaluating the permeate flux over time and the effluent characteristics. The results indicated that it is possible to obtain a permeate flux with suspended solids content with less than 1 mg L-1 oil and a grease concentration in the range of 1 to 3 mg L-1 using membranes with a pore size of 0,1 m. After 50 hours of permeation, the permeate fluxes obtained with the polymeric and ceramic membranes were equal to 50 and 300 L h-1 m-2, respectively. With a chemical regeneration procedure, it was possible to recover 95% of the ceramic membrane’s original permeability and 30% of the polymeric membrane’s permeability. Considering the permeate quality, the regeneration efficiency of the membrane and the fluxes achieved, it is possible to point out the use of ceramic membranes as a potential technology for treating oilfield-produced water, and it has the advantage of being a compact and robust process.

  16. Removal Capacities of Polycyclic Aromatic Hydrocarbons (PAHs) by a Newly Isolated Strain from Oilfield Produced Water.

    Science.gov (United States)

    Qi, Yi-Bin; Wang, Chen-Yu; Lv, Cheng-Yuan; Lun, Zeng-Min; Zheng, Cheng-Gang

    2017-02-22

    The polycyclic aromatic hydrocarbon (PAH)-degrading strain Q8 was isolated from oilfield produced water. According to the analysis of a biochemical test, 16S rRNA gene, house-keeping genes and DNA-DNA hybridization, strain Q8 was assigned to a novel species of the genus Gordonia. The strain could not only grow in mineral salt medium (MM) and utilize naphthalene and pyrene as its sole carbon source, but also degraded mixed naphthalene, phenanthrene, anthracene and pyrene. The degradation ratio of these four PAHs reached 100%, 95.4%, 73.8% and 53.4% respectively after being degraded by Q8 for seven days. A comparative experiment found that the PAHs degradation efficiency of Q8 is higher than that of Gordonia alkaliphila and Gordonia paraffinivorans, which have the capacities to remove PAHs. Fourier transform infrared spectra, saturate, aromatic, resin and asphaltene (SARA) and gas chromatography-mass spectrometry (GC-MS) analysis of crude oil degraded by Q8 were also studied. The results showed that Q8 could utilize n-alkanes and PAHs in crude oil. The relative proportions of the naphthalene series, phenanthrene series, thiophene series, fluorene series, chrysene series, C21-triaromatic steroid, pyrene, and benz(a)pyrene were reduced after being degraded by Q8. Gordonia sp. nov. Q8 had the capacity to remediate water and soil environments contaminated by PAHs or crude oil, and provided a feasible way for the bioremediation of PAHs and oil pollution.

  17. Use of radium isotopes to determine the age and origin of radioactive barite at oil-field production sites

    Science.gov (United States)

    Zielinski, R.A.; Otton, J.K.; Budahn, J.R.

    2001-01-01

    Radium-bearing barite (radiobarite) is a common constituent of scale and sludge deposits that form in oil-field production equipment. The barite forms as a precipitate from radium-bearing, saline formation water that is pumped to the surface along with oil. Radioactivity levels in some oil-field equipment and in soils contaminated by scale and sludge can be sufficiently high to pose a potential health threat. Accurate determinations of radium isotopes (226Ra+228Ra) in soils are required to establish the level of soil contamination and the volume of soil that may exceed regulatory limits for total radium content. In this study the radium isotopic data are used to provide estimates of the age of formation of the radiobarite contaminant. Age estimates require that highly insoluble radiobarite approximates a chemically closed system from the time of its formation. Age estimates are based on the decay of short-lived 228Ra (half-life=5.76 years) compared to 226Ra (half-life=1600 years). Present activity ratios of 228Ra/226Ra in radiobarite-rich scale or highly contaminated soil are compared to initial ratios at the time of radiobarite precipitation. Initial ratios are estimated by measurements of saline water or recent barite precipitates at the site or by considering a range of probable initial ratios based on reported values in modern oil-field brines. At sites that contain two distinct radiobarite sources of different age, the soils containing mixtures of sources can be identified, and mixing proportions quantified using radium concentration and isotopic data. These uses of radium isotope data provide more description of contamination history and can possibly address liability issues. Copyright ?? 2000 .

  18. Hydrogen embrittlement: the game changing factor in the applicability of nickel alloys in oilfield technology

    Science.gov (United States)

    Sarmiento Klapper, Helmuth; Klöwer, Jutta; Gosheva, Olesya

    2017-06-01

    Precipitation hardenable (PH) nickel (Ni) alloys are often the most reliable engineering materials for demanding oilfield upstream and subsea applications especially in deep sour wells. Despite their superior corrosion resistance and mechanical properties over a broad range of temperatures, the applicability of PH Ni alloys has been questioned due to their susceptibility to hydrogen embrittlement (HE), as confirmed in documented failures of components in upstream applications. While extensive work has been done in recent years to develop testing methodologies for benchmarking PH Ni alloys in terms of their HE susceptibility, limited scientific research has been conducted to achieve improved foundational knowledge about the role of microstructural particularities in these alloys on their mechanical behaviour in environments promoting hydrogen uptake. Precipitates such as the γ', γ'' and δ-phase are well known for defining the mechanical and chemical properties of these alloys. To elucidate the effect of precipitates in the microstructure of the oil-patch PH Ni alloy 718 on its HE susceptibility, slow strain rate tests under continuous hydrogen charging were conducted on material after several different age-hardening treatments. By correlating the obtained results with those from the microstructural and fractographic characterization, it was concluded that HE susceptibility of oil-patch alloy 718 is strongly influenced by the amount and size of precipitates such as the γ' and γ'' as well as the δ-phase rather than by the strength level only. In addition, several HE mechanisms including hydrogen-enhanced decohesion and hydrogen-enhanced local plasticity were observed taking place on oil-patch alloy 718, depending upon the characteristics of these phases when present in the microstructure. This article is part of the themed issue 'The challenges of hydrogen and metals'.

  19. Flared natural gas-based onsite atmospheric water harvesting (AWH) for oilfield operations

    Science.gov (United States)

    Wikramanayake, Enakshi D.; Bahadur, Vaibhav

    2016-03-01

    Natural gas worth tens of billions of dollars is flared annually, which leads to resource waste and environmental issues. This work introduces and analyzes a novel concept for flared gas utilization, wherein the gas that would have been flared is instead used to condense atmospheric moisture. Natural gas, which is currently being flared, can alternatively power refrigeration systems to generate the cooling capacity for large scale atmospheric water harvesting (AWH). This approach solves two pressing issues faced by the oil-gas industry, namely gas flaring, and sourcing water for oilfield operations like hydraulic fracturing, drilling and water flooding. Multiple technical pathways to harvest atmospheric moisture by using the energy of natural gas are analyzed. A modeling framework is developed to quantify the dependence of water harvest rates on flared gas volumes and ambient weather. Flaring patterns in the Eagle Ford Shale in Texas and the Bakken Shale in North Dakota are analyzed to quantify the benefits of AWH. Overall, the gas currently flared annually in Texas and North Dakota can harvest enough water to meet 11% and 65% of the water consumption in the Eagle Ford and the Bakken, respectively. Daily harvests of upto 30 000 and 18 000 gallons water can be achieved using the gas currently flared per well in Texas and North Dakota, respectively. In fifty Bakken sites, the water required for fracturing or drilling a new well can be met via onsite flared gas-based AWH in only 3 weeks, and 3 days, respectively. The benefits of this concept are quantified for the Eagle Ford and Bakken Shales. Assessments of the global potential of this concept are presented using data from countries with high flaring activity. It is seen that this waste-to-value conversion concept offers significant economic benefits while addressing critical environmental issues pertaining to oil-gas production.

  20. Kinetic degradation of guar gum in oilfield wastewater by photo-Fenton process.

    Science.gov (United States)

    Wang, Shunwu; Li, Ziwang; Yu, Qinglong

    2017-01-01

    Guar gum is considered as a main component of oilfield wastewater. This work is intended to optimize the experimental conditions (H2O2 dosage, Fe2+ dosage, initial concentration of organics, initial pH and temperature) for the maximum oxidative degradation of guar gum by Fenton's reagent. The kinetics of guar gum removal were evaluated by means of the chemical oxygen demand (COD) and the absorbance measurements. The batch experiment results showed that the optimum conditions were: H2O2 dosage, 10,000 mg/L; Fe2+dosage, 2,000 mg/L; initial concentration of organics, 413 mg/L; pH, 3 and temperature, 35 °C, under which the COD removal could reach 61.07% and fairly good stability could be obtained. Under the optimum experimental conditions, using UV irradiation to treat the wastewater, the photo-Fenton systems can successfully eliminate COD from guar gum solution. The COD removal always obeyed a pseudo-first-order kinetics and the degradation rate (kapp) was increased by 25.7% in the photo-Fenton process compared to the Fenton process. The photo-Fenton system needed less time and consequently less quantity of H2O2 to obtain the same results as the Fenton process. The photo-Fenton process needs a dose of H2O2 20.46% lower than that used in the Fenton process to remove 79.54% of COD. The cost of the photo/Fenton process amounted to RMB9.43/m3, which was lower than that of the classic Fenton process alone (RMB10.58/m3) and the overall water quality of the final effluent could meet the class Ι national wastewater discharge standard for the petrochemical industry of China.

  1. Locally Weighted Naive Bayes

    OpenAIRE

    Frank, Eibe; Hall, Mark; Pfahringer, Bernhard

    2012-01-01

    Despite its simplicity, the naive Bayes classifier has surprised machine learning researchers by exhibiting good performance on a variety of learning problems. Encouraged by these results, researchers have looked to overcome naive Bayes primary weakness - attribute independence - and improve the performance of the algorithm. This paper presents a locally weighted version of naive Bayes that relaxes the independence assumption by learning local models at prediction time. Experimental results s...

  2. Energy Return on Investment (EROI for Forty Global Oilfields Using a Detailed Engineering-Based Model of Oil Production.

    Directory of Open Access Journals (Sweden)

    Adam R Brandt

    Full Text Available Studies of the energy return on investment (EROI for oil production generally rely on aggregated statistics for large regions or countries. In order to better understand the drivers of the energy productivity of oil production, we use a novel approach that applies a detailed field-level engineering model of oil and gas production to estimate energy requirements of drilling, producing, processing, and transporting crude oil. We examine 40 global oilfields, utilizing detailed data for each field from hundreds of technical and scientific data sources. Resulting net energy return (NER ratios for studied oil fields range from ≈2 to ≈100 MJ crude oil produced per MJ of total fuels consumed. External energy return (EER ratios, which compare energy produced to energy consumed from external sources, exceed 1000:1 for fields that are largely self-sufficient. The lowest energy returns are found to come from thermally-enhanced oil recovery technologies. Results are generally insensitive to reasonable ranges of assumptions explored in sensitivity analysis. Fields with very large associated gas production are sensitive to assumptions about surface fluids processing due to the shifts in energy consumed under different gas treatment configurations. This model does not currently include energy invested in building oilfield capital equipment (e.g., drilling rigs, nor does it include other indirect energy uses such as labor or services.

  3. The effect of physical property change on the water flooding development in Changqing oilfield Jurassic low permeability reservoir

    Directory of Open Access Journals (Sweden)

    Yangnan Shangguan

    2015-12-01

    Full Text Available Changqing old oilfield Jurassic reservoir's average calibration recovery is 24.7%, with geological reserves recovery of 16.6%, water cut of 65.2%. And most of Jurassic reservoirs are in the middle and later field life, part of them has entered the high water cut and high recovery stage. Traditional water flooding way for improving oil recovery becomes more difficult, and new method has to be considered. Maling oilfield BS district is a typical representative, with high water cut of 90.8%, high recovery percent of 26.1% and low oil recovery rate of 0.25%. To explore the new way to improve oil recovery, the polymer and surfactant (SP for short important pilot test has been developed. The low permeability reservoir indoor core data in high water cut stage and inspection well results indicate that the reservoir permeability, pore combination characteristics and pore type changed greatly after long-term water flooding development. These changes bring more difficulties to the continue development, especially the high injection pressure, which can cause other problems for well pattern infilling and EOR. This paper takes the high injection pressure problem of Maling BS district Jurassic reservoir for example, analyzes the physical property change law on the following aspects: the development mode in the past, core analysis, formation sensitivity, interstitial matter, well test interpretation results, in order to help to further effective development and provide important parameters for tertiary oil recovery technique for similar reservoirs and others.

  4. Energy Return on Investment (EROI) for Forty Global Oilfields Using a Detailed Engineering-Based Model of Oil Production.

    Science.gov (United States)

    Brandt, Adam R; Sun, Yuchi; Bharadwaj, Sharad; Livingston, David; Tan, Eugene; Gordon, Deborah

    2015-01-01

    Studies of the energy return on investment (EROI) for oil production generally rely on aggregated statistics for large regions or countries. In order to better understand the drivers of the energy productivity of oil production, we use a novel approach that applies a detailed field-level engineering model of oil and gas production to estimate energy requirements of drilling, producing, processing, and transporting crude oil. We examine 40 global oilfields, utilizing detailed data for each field from hundreds of technical and scientific data sources. Resulting net energy return (NER) ratios for studied oil fields range from ≈2 to ≈100 MJ crude oil produced per MJ of total fuels consumed. External energy return (EER) ratios, which compare energy produced to energy consumed from external sources, exceed 1000:1 for fields that are largely self-sufficient. The lowest energy returns are found to come from thermally-enhanced oil recovery technologies. Results are generally insensitive to reasonable ranges of assumptions explored in sensitivity analysis. Fields with very large associated gas production are sensitive to assumptions about surface fluids processing due to the shifts in energy consumed under different gas treatment configurations. This model does not currently include energy invested in building oilfield capital equipment (e.g., drilling rigs), nor does it include other indirect energy uses such as labor or services.

  5. Wakasa Bay Weather Forecast Maps

    Data.gov (United States)

    National Aeronautics and Space Administration — The AMSR-E Wakasa Bay Field Campaign was conducted over Wakasa Bay, Japan, in January and February, 2003. The Wakasa Bay Field Campaign includes joint research...

  6. The right spot : geography, pioneer stock make Red Deer the natural oilfield action central

    Energy Technology Data Exchange (ETDEWEB)

    Laverty Wilson, K.

    2001-09-03

    Red Deer, Alberta, located halfway between Edmonton and Calgary, has become a hot spot for petroleum-related service industries and is known in the industry as the service sector headquarters. In excess of 400 such companies share space in five industrial parks in the city. If proof is required, the Edgar Industrial Park, located adjacent to east-west highway 11 and bordering Highway 2, sold more than half the total acreage to oil and gas industry companies. Trucking companies, fuel distributors and manufacturers that support the industry are also located in the Edgar Industrial Park. There is more happening in this industrial park than just the servicing of vehicles and the storage of equipment. The formulation of special oilfield fluids like drilling muds and fracturing gels is being done. The development of high-technology security systems, the training of workers by industrial education establishments, parts repairs and warehousing are all examples of other activities related to the oil and gas industry taking place at Edgar Industrial Park. The author talked about SAT-TEL, a company that developed the Satellite Monitored Automated Reporting System (SMART), which detects changes in air emissions and the presence of potentially hazardous gases. The information is gathered every five seconds and relayed to the customer who then decides if action is required. Trican Well Service Ltd. employs 200 workers. Part of their work involves the preparation of special blends ranging from formation-fracturing gel to mud and cementing formulas are developed in the laboratory. Red Deer offers the advantage of being centrally located to the main oil and gas fields. The city supports the industry. SPM Flow Control Inc. established a presence in Red Deer as its only supply and refurbishing in Canada, as has Splash and Dore which offers industrial safety, electronic security system and emergency response. High Arctic specializes in snubbing. It optimizes production of pressurized

  7. Potential threat of heavy metals in re-suspended dusts on building surfaces in oilfield city

    Science.gov (United States)

    Kong, Shaofei; Lu, Bing; Bai, Zhipeng; Zhao, Xueyan; Chen, Li; Han, Bin; Li, Zhiyong; Ji, Yaqin; Xu, Yonghai; Liu, Yong; Jiang, Hua

    2011-08-01

    30 re-suspended dust samples were collected from building surfaces of an oilfield city, then re-suspended through PM 2.5, PM 10 and PM 100 inlets and analyzed for 10 metals including V, Cr, Mn, Co, Ni, Cu, Zn, As, Cd and Pb by inductively coupled plasma-mass spectroscopy. Metals concentrations in different fractions and locations were studied. Metals sources were identified by cluster and primary component analysis. The potential risk to human health was assessed by human exposure model. Results showed that Zn, Mn, Pb and Cu were higher in all the three fractions. V, Cr, Mn and Co ranged close to the background values of Chinese soil indicating that they were mainly from crustal materials. Concentrations of Zn, Mn, Pb, V, Cr, Ni, Co and Cd were higher in old district than that in new district for the three fractions. The PM 2.5/PM 10, PM 10/PM 100 and PM 2.5/PM 100 ratios were higher for Zn, Cd, Cu, Pb, Ni, As and Cr (all higher than 1.0), and lower for Co, Mn and V (all less than or close to 1.0) which meant that anthropologic sources associated metals were more easily accumulated in finer particles than metals from crustal materials. Spatial variations indicated that the ten metals peaked at surroundings near railway station, gas stations, industrial boilers and machine manufacturing plant implying the influence of local vehicle emission, fossil fuel combustion and industrial activities as well as crustal materials which was verified by cluster analysis and primary component analysis results. Ingestion of dust particles appeared to be the main route of exposure to re-suspended dust. Hazard Indexes of As were both highest for children and adult which could be a potential threat to human health for non-cancer effect and it also exhibited the highest values for cancer effect as 1.01E-06, 7.04E-07 and 7.21E-07 for PM 2.5, PM 10 and PM 100, respectively.

  8. eBay.com

    DEFF Research Database (Denmark)

    Engholm, Ida

    2014-01-01

    Celebrated as one of the leading and most valuable brands in the world, eBay has acquired iconic status on par with century-old brands such as Coca-Cola and Disney. The eBay logo is now synonymous with the world’s leading online auction website, and its design is associated with the company...

  9. INEEL Biotechnology for Oilfield Application--Microbial Enhanced Oil Recovery FY-03 Report

    Energy Technology Data Exchange (ETDEWEB)

    G. A. Bala; D. F. Bruhn; S. L. Fox; K. S. Noah; K. D. Schaller; E. P. Robertson; X. Xie

    2003-11-01

    The Idaho National Engineering and Environmental Laboratory (INEEL) Biotechnology for Oilfield Operations program supports development, engineering, and application of biotechnology for exploration and production. This continuing INEEL program also supports mitigation of detrimental field conditions. The program is consistent with the United States Department of Energy mission to ¡§promote activities and policies through its oil technology and natural gas supply programs to enhance the efficiency and environmental quality of domestic oil and natural gas exploration, recovery, processing, transport, and storage.¡¨ In addition, the program directly supports the focus areas of Reservoir Life Extension; Advanced Drilling, Completion and Stimulation Systems; Effective Environmental Protection; and Cross Cutting Areas. The program is enhanced by collaborative relationships with industry and academia. For fiscal year 2003, the program focused on production and characterization of biological surfactants from agricultural residuals and the production and application of reactive microbial polymers. This report specifically details: 1. Use of a chemostat reactor operated in batch mode for producing surfactin, with concomitant use of an antifoam to prevent surfactant loss. The program achieved production and recovery of 0.6 g/L of surfactin per 12 hr. 2. Characterization of surfactin produced from agricultural residuals with respect to its ability to mediate changes in surface tension. Conditions evaluated were salt (as NaCl) from 0 to 10% (w/v), pH from 3 to 10, temperature from 21 to 70¢XC, and combinations of these conditions. When evaluated singularly, pH below 6 and salt concentrations above 30 g/L were found to have an adverse impact on surfactin. Temperatures of 70¢XC for 95 days had no effect. When the effect of temperature was added to the pH experiment, there were no significant changes, and, again, surface tension, at any temperature, increased at pH below 6

  10. The effect of alloying on the resistance of carbon steel for oilfield applications to CO2 corrosion

    Directory of Open Access Journals (Sweden)

    David V. Edmonds

    2005-12-01

    Full Text Available A systematic study has been conducted to investigate the influence of a wide range of alloying elements and different processing conditions on the resistance of low-carbon steels to CO2 corrosion. Strong carbide-forming microalloying elements such as Ti, Nb and V, along with Cr additions, and different levels of Mn, Si, Cu, Mo and Ni, have been explored, along with treatments simulating different processing conditions, for example, controlled rolling, and quenching and tempering. Corrosion testing, including flow loop tests, has been carried out, along with evaluation of mechanical properties, weldability and hot ductility. The programme has developed steels with improved CO2 corrosion resistance and hence identified a potential route for producing more economical carbon steels for oilfield applications. The work has been carried out as part of the UK- Brazil Corrosion Network.

  11. Integrating naive Bayes and FOIL

    OpenAIRE

    Landwehr, Niels; Kersting, Kristian; De Raedt, Luc

    2007-01-01

    A novel relational learning approach that tightly integrates the naive Bayes learning scheme with the inductive logic programming rule-learner FOIL is presented. In contrast to previous combinations that have employed naive Bayes only for post-processing the rule sets, the presented approach employs the naive Bayes criterion to guide its search directly. The proposed technique is implemented in the NFOIL and TFOIL systems, which employ standard naive Bayes and tree augmented naive Bayes model...

  12. Hammond Bay Biological Station

    Data.gov (United States)

    Federal Laboratory Consortium — Hammond Bay Biological Station (HBBS), located near Millersburg, Michigan, is a field station of the USGS Great Lakes Science Center (GLSC). HBBS was established by...

  13. Humboldt Bay Orthoimages

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set consists of 0.5-meter pixel resolution, four band orthoimages covering the Humboldt Bay area. An orthoimage is remotely sensed image data in which...

  14. Biscayne Bay Alongshore Epifauna

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Field studies to characterize the alongshore epifauna (shrimp, crabs, echinoderms, and small fishes) along the western shore of southern Biscayne Bay were started in...

  15. Sequence Stratigraphy of lower zones of Asmari Formation in Marun Oilfield by using of microfacies analysis, isolith maps and γ- Ray log

    Directory of Open Access Journals (Sweden)

    Ahmad Mirmarghabi

    2015-02-01

    Full Text Available The Oligo- Miocene Asmari Formation is one of the most important reservoir units of the Marun Oilfield in Dezful Embayment SW Iran, deposited in Zagros foreland basin. The goal of this study is to interpret depositional environment and sequence stratigraphy of lower zones of the Asmari Formation in Well No.281, 342 and 312in Marun Oilfield based on changes in the shape of γ- Ray, isolith maps and microfacies properties. Accordingly, identification of 9 carbonate microfacies and 2 siliciclastic petrofacies were identified that are deposited in four depositional environment including open marine, barrier, lagoon and tidal flat in a homoclinal ramp (consisting of outer, middle and inner ramp. Also, based on the shape of γ- Ray log, There sediment were deposited in marine environment. In open marine and barrier environments, The shape of γ- Ray log is serrated bell-shaped, serrated funnel-shaped, left bow-shaped, serrated shape and right boxcar shape, Whole in the beach environment it is cylinder and funnel shape and in lagoon and tidal flat environment can be seen on right bow to cylinder-shaped. Based on the isolith maps, sandstone of lower zones of the Asmari Formation in Marun Oilfield expanded by deltaic system along the southwestern margin of the basin and influenced by changes in sea level constantly. Sequence stratigraphic analysis led to identification of three third- order (DS1, DS2 and DS3 depositional sequences.

  16. Sequence Stratigraphy of lower zones of Asmari Formation in Marun Oilfield by using of microfacies analysis, isolith maps and γ- Ray log

    Directory of Open Access Journals (Sweden)

    Jalil Jafari

    2015-01-01

    Full Text Available The Oligo- Miocene Asmari Formation is one of the most important reservoir units of the Marun Oilfield in Dezful Embayment SW Iran, deposited in Zagros foreland basin. The goal of this study is to interpret depositional environment and sequence stratigraphy of lower zones of the Asmari Formation in Well No.281, 342 and 312in Marun Oilfield based on changes in the shape of γ- Ray, isolith maps and microfacies properties. Accordingly, identification of 9 carbonate microfacies and 2 siliciclastic petrofacies were identified that are deposited in four depositional environment including open marine, barrier, lagoon and tidal flat in a homoclinal ramp (consisting of outer, middle and inner ramp. Also, based on the shape of γ- Ray log, There sediment were deposited in marine environment. In open marine and barrier environments, The shape of γ- Ray log is serrated bell-shaped, serrated funnel-shaped, left bow-shaped, serrated shape and right boxcar shape, Whole in the beach environment it is cylinder and funnel shape and in lagoon and tidal flat environment can be seen on right bow to cylinder-shaped. Based on the isolith maps, sandstone of lower zones of the Asmari Formation in Marun Oilfield expanded by deltaic system along the southwestern margin of the basin and influenced by changes in sea level constantly. Sequence stratigraphic analysis led to identification of three third- order (DS1, DS2 and DS3 depositional sequences.

  17. Bayes and the Law.

    Science.gov (United States)

    Fenton, Norman; Neil, Martin; Berger, Daniel

    2016-06-01

    Although the last forty years has seen considerable growth in the use of statistics in legal proceedings, it is primarily classical statistical methods rather than Bayesian methods that have been used. Yet the Bayesian approach avoids many of the problems of classical statistics and is also well suited to a broader range of problems. This paper reviews the potential and actual use of Bayes in the law and explains the main reasons for its lack of impact on legal practice. These include misconceptions by the legal community about Bayes' theorem, over-reliance on the use of the likelihood ratio and the lack of adoption of modern computational methods. We argue that Bayesian Networks (BNs), which automatically produce the necessary Bayesian calculations, provide an opportunity to address most concerns about using Bayes in the law.

  18. Evolving extended naive Bayes classifiers

    OpenAIRE

    Klawonn, Frank; Angelov, Plamen

    2006-01-01

    Naive Bayes classifiers are a very simple, but often effective tool for classification problems, although they are based on independence assumptions that do not hold in most cases. Extended naive Bayes classifiers also rely on independence assumptions, but break them down to artificial subclasses, in this way becoming more powerful than ordinary naive Bayes classifiers. Since the involved computations for Bayes classifiers are basically generalised mean value calculations, they easily render ...

  19. Mapping local singularities using magnetic data to investigate the volcanic rocks of the Qikou depression, Dagang oilfield, eastern China

    Directory of Open Access Journals (Sweden)

    G. Chen

    2013-07-01

    Full Text Available The spatial structural characteristics of geological anomaly, including singularity and self-similarity, can be analysed using fractal or multifractal modelling. Here we apply the multifractal methods to potential fields to demonstrate that singularities can characterise geological bodies, including rock density and magnetic susceptibility. In addition to enhancing weak gravity and magnetic anomalies with respect to either strong or weak background levels, the local singularity index (α ≈ 2 can be used to delineate the edges of geological bodies. Two models were established to evaluate the effectiveness of mapping singularities for extracting weak anomalies and delineating edges of buried geological bodies. The Qikou depression of the Dagang oilfield in eastern China has been chosen as a study area for demonstrating the extraction of weak anomalies of volcanic rocks, using the singularity mapping technique to analyse complex magnetic anomalies caused by complex geological background. The results have shown that the singularities of magnetic data mapped in the paper are associated with buried volcanic rocks, which have been verified by both drilling and seismic survey, and the S–N and E–W faults in the region. The targets delineated for deeply seated faults and volcanic rocks in the Qikou depression should be further investigated for the potential application in undiscovered oil and gas reservoirs exploration.

  20. Geochemical investigation of petroleum source rocks by using Rock- Eval data in the Agha-Jari oilfield

    Directory of Open Access Journals (Sweden)

    Behzad khani

    2015-01-01

    Full Text Available In this study, 40 drilling cutting of the Pabdeh, Gurpi, kazhdumi and Gadvan Formations from the Agha-Jari Oilfield were analyzed by using Rock-Eval pyrolysis. In order to recognizing sedimentary environmental conditions of studied Formations, they are divided to 4 zones which A (Kazhdumi Formation#187 and C (Kazhdumi Formation#140 zones show reduction conditions by presence of sea organic materials and B (Gadvan Formation #140 and D(Gadvan Formation#187 zones show oxidation conditions by presence of continental organic materials to basin. Based on the Rock-Eval pyrolysis data, the Pabeh, Gurpi, Kazhdumi and Gadvan Formations have variable hydrocarbon generative potential. HI vs. OI plot revealed that the kerogen type in this Formations is a mixed of types II & III. The intensity of matrix effect in the Pabdeh, Gurpi, Kazhdumi and Gadvan Formations was compared by using S2 vs. TOC plot and calculating its regression equation. The results show that the significant amount of S2 adsorption by matrix was happened in the Pabdeh (4.98-6.96 mg HC/gr rock in wells 113 and 121 and Gurpi Formations ‌(4.33 mg HC/gr rock in well 113 which is due to their low thermal maturity‌(Tmax

  1. Strontium isotope systematics of mixing groundwater and oil-field brine at Goose Lake in northeastern Montana, USA

    Science.gov (United States)

    Peterman, Zell E.; Thamke, Joanna N.; Futa, Kiyoto; Preston, Todd

    2012-01-01

    Groundwater, surface water, and soil in the Goose Lake oil field in northeastern Montana have been affected by Cl−-rich oil-field brines during long-term petroleum production. Ongoing multidisciplinary geochemical and geophysical studies have identified the degree and local extent of interaction between brine and groundwater. Fourteen samples representing groundwater, surface water, and brine were collected for Sr isotope analyses to evaluate the usefulness of 87Sr/86Sr in detecting small amounts of brine. Differences in Sr concentrations and 87Sr/86Sr are optimal at this site for the experiment. Strontium concentrations range from 0.13 to 36.9 mg/L, and corresponding 87Sr/86Sr values range from 0.71097 to 0.70828. The local brine has 168 mg/L Sr and a 87Sr/86Sr value of 0.70802. Mixing relationships are evident in the data set and illustrate the sensitivity of Sr in detecting small amounts of brine in groundwater. The location of data points on a Sr isotope-concentration plot is readily explained by an evaporation-mixing model. The model is supported by the variation in concentrations of most of the other solutes.

  2. Distribution of petroleum degrading genes and factor analysis of petroleum contaminated soil from the Dagang Oilfield, China

    Science.gov (United States)

    Liu, Qinglong; Tang, Jingchun; Bai, Zhihui; Hecker, Markus; Giesy, John P.

    2015-01-01

    Genes that encode for enzymes that can degrade petroleum hydrocarbons (PHs) are critical for the ability of microorganisms to bioremediate soils contaminated with PHs. Distributions of two petroleum-degrading genes AlkB and Nah in soils collected from three zones of the Dagang Oilfield, Tianjin, China were investigated. Numbers of copies of AlkB ranged between 9.1 × 105 and 1.9 × 107 copies/g dry mass (dm) soil, and were positively correlated with total concentrations of PHs (TPH) (R2 = 0.573, p = 0.032) and alkanes (C33 ~ C40) (R2 = 0.914, p soil, and was negatively correlated with concentrations of total aromatic hydrocarbons (TAH) (R2 = −0.567, p = 0.035) and ∑16 PAHs (R2 = −0.599, p = 0.023). Results of a factor analysis showed that individual samples of soils were not ordinated as a function of the zones. PMID:26086670

  3. Assessment of the potential environmental fate and effects of oil-field discharge waters containing {sup 226}radium

    Energy Technology Data Exchange (ETDEWEB)

    Herrera, A.W.; Hill, S.L.; Bergman, H.L. [Univ. of Wyoming, Laramie, WY (United States). Dept. of Zoology and Physiology

    1994-12-31

    The naturally occurring radionuclide, radium-226, has been detected in oil production waters in all regions of the country. A produced water discharge into the Loch Katrina wetland in Park County, WY was investigated with respect to the transport and fate of radium in surface waters. The 866-acre Loch Katrina wetland complex is sustained primarily by oil-field produced waters and provides habitat for many species of aquatic birds. While the short-term benefits of this discharge are indisputable, the long-term hazards posed by the transport of radium from deep aquifers to surface waters are not well understood. Guidelines regulating the management of radium-contaminated sediments in receiving waters or settling ponds in Wyoming have yet to be established. The purpose of this study was to provide information to regional regulatory agencies and the oil and gas industry in the development of guidelines and procedures for managing radium and other naturally occurring radioactive materials. The authors will report the results of the sampling survey of produced waters, sediment and biota performed in the Loch Katrina wetland complex in Wyoming.

  4. Matching Relationship and Alternating Injection for Polymer Flooding in Heterogeneous Formations: A Laboratory Case Study of Daqing Oilfield

    Directory of Open Access Journals (Sweden)

    Songyuan Liu

    2017-07-01

    Full Text Available A series of experiments were carried out to study the relationship between polymer and reservoir permeability, as well as the alternating injection pattern for heterogeneous formations. The polymer molecular size (MS was studied using dynamic light scattering. The parameters such as hydraulic radius, molecular weight (MW, concentrations and salinity were studied. The injection capacity and the relationship between polymer and formation were obtained using injection experiments with natural cores, which represent different regions in the Daqing oilfield. Moreover, an improved injection pattern, alternating injection in heterogeneous formation was studied based on the injection experiments of parallel and in-layer heterogeneous artificial cores. The alternate cycle and slug size were investigated. It was proven that the alternating injection can improve the efficiency of low permeability layers up to 7.3% and a mean value of 4.27%. It was also found that the mechanism of alternating injection is blocking the high permeability layers and improving the water injection profile. We suggest that other fields with high heterogeneity could try the alternating injection to optimize the polymer flooding. Meanwhile, further pilot tests or numerical simulation of polymer alternating injection in heterogeneous formation (formation type II should be conducted.

  5. Synthesis of bridged β-cyclodextrin–polyethylene glycol and evaluation of its inhibition performance in oilfield wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Changjun, E-mail: changjunzou@126.com; Liu, Yuan; Yan, Xueling; Qin, Yibie; Wang, Meng; Zhou, Lu

    2014-10-15

    The bridged β-cyclodextrin–polyethylene glycol (β-CD–PEG) is synthesized through reaction of β-CD with PEG, which has been characterized by Fourier transform infrared spectroscope. The inhibition efficiency of bridged β-CD–PEG on corrosion of Q235 carbon steel in 0.5 M HCl solution has been investigated by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and weight loss measurements. The results show that β-CD–PEG acted as a mixed-type inhibitor and performed excellent inhibiting effect for the corrosion of the Q235 carbon steel. The steel surface morphologies are analyzed using scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) and then an adsorption mechanism model is proposed. The high inhibitory efficiency of β-CD–PEG is related with the adsorption of polymer molecules at the steel surface and a protective film formation. Finally, these results present a novel corrosion inhibitor works in oil-gas field. - Highlights: • The bridged β-CD–PEG is synthesized by polyethylene glycol and cyclodextrin. • The bridged β-CD–PEG acts as an inhibitor for carbon steel in oilfield wastewater. • The high inhibitory efficiency is related with a protective film formation. • The adsorption of β-CD–PEG is well described by the Langmuir adsorption isotherm.

  6. Experimental Study of Rheological Properties and Oil Displacement Efficiency in Oilfields for a Synthetic Hydrophobically Modified Polymer.

    Science.gov (United States)

    Liu, Pengcheng; Mu, Zhenbao; Wang, Chao; Wang, Yanling

    2017-08-18

    In a previous study, we developed a synthetic hydrophobically modified hydroxyethyl cellulose (HEC) using bromododecane (BD), which we denote as BD-HMHEC. In this work, we continually investigate the rheological properties and its oil displacement efficiency in PuTao well area in Daqing oilfields, China. Results show that BD-HMHEC solution has good viscosification, thermal-resistance, salt-tolerance, shear resistance, and acid/alkali resistance. The storage modulus (G') and the loose modulus (G") of the BD-HMHEC solutions increase significantly with increasing BD-HMHEC concentration, and the solution becomes viscoelastic at a sufficiently high BD-HMHEC concentration. The core flooding results showed BD-HMHEC flooding improves oil recovery by 7-14% in comparison with HEC flooding at concentrations of 4,000 mg/L under equivalent conditions. Moreover, BD-HMHEC flooding improves oil recovery by 7-8% after conducting water and hydrolyzed polyacrylamide (HPAM) flooding. The oil displacement mechanism of BD-HMHEC solutions is discussed based on a visual evaluation. The results indicate that BD-HMHEC flooding is a feasible means for improving oil recovery after water/HPAM flooding.

  7. Application of PAC and flocculants for improving settling of solid particles in oilfield wastewater with high salinity and Ca2.

    Science.gov (United States)

    Liu, Guoliang; Zhang, Fusheng; Qu, Yuanzhi; Liu, He; Zhao, Lun; Cui, Mingyue; Ou, Yangjian; Geng, Dongshi

    2017-09-01

    The suspended solids in wastewater from Rekabak oilfield, Kazakhstan, were characterized and treated with flocculants to enhance settling. The wastewater contained a high concentration of total dissolved solids and calcium ion. Scanning electron microscopy and energy dispersive X-ray analyses showed that suspended solids were mainly composed of corrosion products (iron oxides) and silicon dioxide particles. Also, much salt deposition from wastewater caused a large increase in the suspended solids value. The settling of solid particles in wastewater was investigated by turbidity decrease within 60 min. The particle settling was enhanced by adding polyaluminum chloride (PAC) as coagulant and hydrolyzed polyacryamide (HPAM) or cationic polyacrylamide (CPAM) as flocculant. At optimal dose, the particle settling ability with PAC and CPAM was better than that with PAC and HPAM. Particle size analysis showed that HPAM or CPAM with high molecular weight played an important role for enlarging the particle size. The experiments with simulated wastewater showed that particle settling by using HPAM deteriorated significantly compared to that by CPAM at high calcium ion. This study provides further understanding about the effect of high salinity and Ca2+ on solids formation, flocculant performance and particle settling. Meanwhile, the results are also helpful to develop novel flocculants used for high salinity wastewater.

  8. Down by the Bay

    Science.gov (United States)

    Allison, Elizabeth; Tunks, Karyn; Hardman, Kacie

    2017-01-01

    The Pelican's Nest, located near Mobile Bay in the Gulf of Mexico, is a science center supported by a local educational foundation. Programs are geared toward marine wildlife and the coastal habitat with an emphasis on hands-on learning for students in grades K-6. The director of the science center conducts daily classroom labs and discovery trips…

  9. Richards Bay effluent pipeline

    CSIR Research Space (South Africa)

    Lord, DA

    1986-07-01

    Full Text Available 3815 9 D A Lord Department of Oceanography University of Port Elizabeth P 0 Box 1600 PORT ELIZABETH 6000 N D Geldenhuys Department of Environment Affairs Private Bag X9005 CAPE TOWN 8000 Cover: Richards Bay from the air showing city... of major concern identified in the effluent are the large volume of byproduct calcium sulphate (phosphogypsum) which would smother marine life, high concentrations of fluoride highly toxic to marine life, heavy metals, chlorinated organic material...

  10. Static reservoir modeling of the Bahariya reservoirs for the oilfields development in South Umbarka area, Western Desert, Egypt

    Science.gov (United States)

    Abdel-Fattah, Mohamed I.; Metwalli, Farouk I.; Mesilhi, El Sayed I.

    2018-02-01

    3D static reservoir modeling of the Bahariya reservoirs using seismic and wells data can be a relevant part of an overall strategy for the oilfields development in South Umbarka area (Western Desert, Egypt). The seismic data is used to build the 3D grid, including fault sticks for the fault modeling, and horizon interpretations and surfaces for horizon modeling. The 3D grid is the digital representation of the structural geology of Bahariya Formation. When we got a reasonably accurate representation, we fill the 3D grid with facies and petrophysical properties to simulate it, to gain a more precise understanding of the reservoir properties behavior. Sequential Indicator Simulation (SIS) and Sequential Gaussian Simulation (SGS) techniques are the stochastic algorithms used to spatially distribute discrete reservoir properties (facies) and continuous reservoir properties (shale volume, porosity, and water saturation) respectively within the created 3D grid throughout property modeling. The structural model of Bahariya Formation exhibits the trapping mechanism which is a fault assisted anticlinal closure trending NW-SE. This major fault breaks the reservoirs into two major fault blocks (North Block and South Block). Petrophysical models classified Lower Bahariya reservoir as a moderate to good reservoir rather than Upper Bahariya reservoir in terms of facies, with good porosity and permeability, low water saturation, and moderate net to gross. The Original Oil In Place (OOIP) values of modeled Bahariya reservoirs show hydrocarbon accumulation in economic quantity, considering the high structural dips at the central part of South Umbarka area. The powerful of 3D static modeling technique has provided a considerable insight into the future prediction of Bahariya reservoirs performance and production behavior.

  11. Oilfield water treatment by electrocoagulation-reverse osmosis for agricultural use: effects on germination and early growth characteristics of sunflower.

    Science.gov (United States)

    de Souza, Paulo S A; Cerqueira, Alexandre A; Rigo, Michelle M; de Paiva, Julieta L; Couto, Rafael S P; Merçon, Fábio; Perez, Daniel V; Marques, Monica R C

    2017-05-01

    This study aims to evaluate the effects of oilfield water (OW), treated by a hybrid process of electrocoagulation and reverse osmosis (EC-RO), on seed germination and early growth characteristics of sunflower (Heliantus annus L.). In the EC step, tests were conducted with 28.6 A m -2 current density and 4 min. reaction time. In the RO step, the system was operated with 1 L min -1 constant flow and 2 MPa, 2.5 MPa and 3 MPa feed pressures. In all feed pressures, RO polymeric membranes achieved very high removals of chemical oxygen demand (up to 89%) and oils and greases (100%) from EC-treated effluent. In best feed pressure (2.5 MPa), turbidity, total dissolved salts, electrical conductivity, salinity, toxic ions and sodium adsorption ratio values attained internationally recognized standards for irrigation water. Using EC-RO (feed pressure:2.5 MPa) treated OW, germinated sunflower seeds percentage (86 ± 6%), speed of germination (30 ± 2) and biomass production (49 ± 5 mg) were statistically similar to control (distilled water) results. Vigor index average values obtained using OW treated by EC-RO (3871)were higher than that obtained by OW water treated by EC (3300). The results of this study indicate that EC-RO seems to be a promising alternative for treatment of OW aiming sunflower crops irrigation, since the use of this treated effluent did not affect adversely seed germination and seedling development, and improved seedling vigor. Furthermore, OW treatment by EC-RO reduces sodium levels into acceptable standards values avoiding soil degradation.

  12. Oil pollution in the Red Sea — Environmental monitoring of an oilfield in a coral area, Gulf of Suez

    Science.gov (United States)

    Dicks, Brian

    The Red Sea is rapidly developing as one of the world's largest offshore oil production areas. It also comprises a wide range of tropical marine habitats, many of which are internationally recognised for their conservation, scientific, economic or recreational value. Past oil production, refining and transport have resulted in chronic pollution of some areas, and environmental programmes to protect new areas of development from pollution damage are assuming increasing importance. At the initiative of an Egyptian oil company operating in the Gulf of Suez, an environmental protection and management scheme has been prepared for a new offshore oilfield and marine terminal at Ras Budran. This paper describes the form of the scheme and the results of its component environmental surveys. The development area comprises rich and diverse marine communities of fringing coral reefs, nearshore lagoons, seagrass beds, sandy beaches and fine sediments offshore. A baseline survey was designed following detailed discussion of the scope of the development with the company and a preliminary site visit, and the fieldwork was completed in October 1980. On the basis of the findings of the survey, a series of recommendations was made to the company, aimed at reducing environmental impacts during construction and operation to a minimum and acceptable level. These were subsequently implemented and the results of a post-construction survey in February 1983 are reported which show that environmental damage to the nearshore habitats during the construction phase had been relatively small and localised. Recently, the biological information obtained from the two surveys has also been incorporated into oil spill contingency plans.

  13. Legal aspects and technical alternatives for the treatment of reservoir brines at the Activo Luna oilfield, Mexico.

    Science.gov (United States)

    Birkle, Peter; Cid Vázquez, Adolfo L; Fong Aguilar, J L

    2005-01-01

    Deep formation water, extracted as an undesired byproduct from on-shore production wells at the Activo Luna oilfield and processed in adjacent oil fields, are highly enriched in salt minerals, especially in sodium chloride (NaCl) (262 000 mg/L), but also in metals and nonmetals, such as strontium (Sr) (2068 mg/L), bromine (Br) (2034 mg/L), boron (B) (396 mg/ L), iodine (I) (43.4 mg/L), selenium (Se) (3.74 mg/L), and arsenic (As) (0.55 mg/L). Direct reinjection of the brine underground is not possible because of elevated pressure conditions within the petroleum reservoir. The disposal into near shore areas of the Gulf of Mexico without treatment must be rejected because of a) elevated concentrations of some toxic elements, such as B, silver (Ag), thallium (Tl), Se and cadmium (Cd), which exceed permissible limits of environmental legislation for surface discharge (Official Mexican norms NOM-001-ECOL-1998 and CE-CCA-001/89), and b) differences in density that could cause the descent of hypersaline fluid to the ocean floor, potentially affecting the diversity and survival of the benthic ecosystem. Conventional treatment techniques, such as microfiltration or reverse osmosis, are not suitable for the Activo Luna brines because of their extreme mineralization, which will cause pressure conditions exceeding 200 bars across the membrane. As an alternative process, the evaporation of the entire brine volume of approximately 200 m3/day by solar ponds or industrial crystallization plants is suggested. The residual precipitated residuals are composed mainly of chlorine (Cl) (9460 tons/year), sodium (Na) (4230 tons/ year), calcium (Ca) (1028 tons/year), potassium (K) (207 tons/year), and magnesium (Mg) (65.8 tons/year). As an alternative to its disposal on a dumpsite, some special minerals (especially NaCl, Mg, Sr, and Br) could be recovered for its economic value.

  14. Alkanindiges illinoisensis gen. nov., sp. nov., an obligately hydrocarbonoclastic, aerobic squalane-degrading bacterium isolated from oilfield soils.

    Science.gov (United States)

    Bogan, Bill W; Sullivan, Wendy R; Kayser, Kevin J; Derr, K D; Aldrich, Henry C; Paterek, J Robert

    2003-09-01

    An alkane-degrading bacterium, designated GTI MVAB Hex1(T), was isolated from chronically crude oil-contaminated soil from an oilfield in southern Illinois. The isolate grew very weakly or not at all in minimal or rich media without hydrocarbons. Straight-chain aliphatic hydrocarbons, such as hexadecane and heptadecane, greatly stimulated growth; shorter-chain (squalane. The latter of these was most intriguing, as catabolism of squalane has hitherto been reported only for Mycobacterium species. Although unable to utilize mono- or polycyclic aromatic hydrocarbons as sole carbon sources, the isolate did show slight fluorene-mineralizing capability in Luria-Bertani medium, which was partially repressed by hexadecane. In contrast, hexadecane supplementation greatly increased mineralization of (14)C-dodecane, which was not a growth substrate. Further testing emphasized the isolate's extremely narrow substrate range, as only Tween 40 and Tween 80 supported significant growth. Microscopic examination (by scanning and transmission electron microscopy) revealed a slightly polymorphic coccoidal to bacillar morphology, with hydrocarbon-grown cells tending to be more elongated. When grown with hexadecane, GTI MVAB Hex1(T) accumulated a large number of electron-transparent intracytoplasmic inclusion bodies. These were also prevalent during growth in the presence of squalane. Smaller inclusion bodies were observed occasionally with pristane supplementation; they were, however, absent during growth on crude oil. On the basis of 16S rRNA gene sequence data and range of growth substrates, classification of this isolate as the type strain of Alkanindiges illinoisensis gen. nov., sp. nov. is proposed, which is most closely related (approx. 94 % sequence similarity) to Acinetobacter junii.

  15. Multiphase Calcite Cementation and Fluids Evolution of a Deeply Buried Carbonate Reservoir in the Upper Ordovician Lianglitag Formation, Tahe Oilfield, Tarim Basin, NW China

    OpenAIRE

    Jiaqing Liu; Zhong Li; Lijuan Cheng; Jiawei Li

    2017-01-01

    Oil and gas have been found in the Upper Ordovician Lianglitag Formation carbonates in the Tahe Oilfield, Tarim Basin, NW China. This study documents the origin of diagenetic fluids by using a combination of petrology, SIMS, fluid inclusion, and radiogenic isotope analysis. Six stages of calcite cements were revealed. C1-C2 formed in marine to early burial environments. C3 has relatively low δ18OVPDB values (−8.45‰ to −6.50‰) and likely has a meteoric origin. Meteoric water probably fluxed in...

  16. 78 FR 27989 - Bandon Marsh, Nestucca Bay, and Siletz Bay National Wildlife Refuges, Coos, Tillamook, and...

    Science.gov (United States)

    2013-05-13

    ... Fish and Wildlife Service Bandon Marsh, Nestucca Bay, and Siletz Bay National Wildlife Refuges, Coos... Assessments (EAs) for three Oregon refuges--Bandon Marsh, Nestucca Bay, and Siletz Bay National Wildlife... ``Bandon Marsh, Nestucca Bay, and Siletz Bay final CCPs and FONSIs'' in the subject line of the message. U...

  17. 75 FR 73121 - Bandon Marsh, Nestucca Bay, and Siletz Bay National Wildlife Refuges, Coos, Tillamook, and...

    Science.gov (United States)

    2010-11-29

    ... Fish and Wildlife Service Bandon Marsh, Nestucca Bay, and Siletz Bay National Wildlife Refuges, Coos... prepare a comprehensive conservation plan (CCP) for the Bandon Marsh, Nestucca Bay, and Siletz Bay... ``Bandon Marsh, Nestucca Bay, and Siletz Bay CCP'' in the subject line of the message. Fax: Attn: Project...

  18. BCDC Bay Trail Alignment 2009

    Data.gov (United States)

    California Department of Resources — The Bay Trail provides easily accessible recreational opportunities for outdoor enthusiasts, including hikers, joggers, bicyclists and skaters. It also offers a...

  19. Evaluating the Sealing Effectiveness of a Caprock-Fault System for CO2-EOR Storage: A Case Study of the Shengli Oilfield

    Directory of Open Access Journals (Sweden)

    Bing Bai

    2017-01-01

    Full Text Available An effective sealing system is crucial for CO2-EOR storage, and these sealing systems are typically composed of the caprocks and faults that surround a reservoir. Therefore, the sealing effectiveness of a caprock-fault system must be evaluated at various stages of CO2-EOR storage projects. This paper presents a new evaluation framework that considers specific site characteristics and a case study on the sealing effectiveness of the caprock-fault system in the Shengli Oilfield. The proposed method is a weighted ranking system where a set of 17 indicators has been developed for the assessment and ranking of the G89 block in terms of their sealing ability for CO2 sequestration. Additional indicators are involved in the method, such as the newly proposed parameter, frontier displacement work which reflects the influence of formation pressure, displacement pressure resistance, and caprock thickness. The new approach considers the sealing mechanisms of caprocks and faults as well as the configuration relationships between them. The method was used to evaluate the sealing effectiveness of the G89 block that has a considerable number of faults and good sealing ability of caprock in the Shengli Oilfield.

  20. The biofilm property and its correlationship with high-molecular-weight polyacrylamide degradation in a water injection pipeline of Daqing oilfield.

    Science.gov (United States)

    Li, Cai-Yun; Zhang, Dong; Li, Xiao-Xiao; Mbadinga, Serge Maurice; Yang, Shi-Zhong; Liu, Jin-Feng; Gu, Ji-Dong; Mu, Bo-Zhong

    2016-03-05

    Biofilms increase dragging force for liquid transportation, cause power consumption, and result in equipment corrosion in polymer-flooding oilfields. To reveal the responsible microorganisms for biofilm formation and stability of high-molecular-weight polyacrylamide (PAM), a biofilm, developed on the sieve of a piston plunger pump in a water transport and injection pipeline with partial hydrolyzed polyacrylamide (HPAM) in Daqing Oilfield, was collected and analyzed by molecular microbiology, chemical and physical methods. Diverse bacterial groups (11 families) were detected in the biofilm, including Pseudomonadaceae, Rhodocyclaceae, Desulfobulbaceae, Alcaligenaceae, Comamonadaceae, Oxalobacteraceae, Bacteriovoracaceae, Campylobacteraceae, Flavobacteriaceae, Clostridiales Incertae Sedis XIII and Moraxellaceae. Three archaeal orders of methanogens including Methanomicrobiales, Methanosarcinales and Thermoplasmatales were also detected separately. HPAM was degraded into lower molecular weight polymers and organic fragments with its amide groups hydrolyzed into carboxylic groups by the microorganisms. The microenvironment of the biofilm contained diverse bacterial and archaeal communities, correlating with the extracellular polymeric substance (EPS) and HPAM biodegradation. The results are helpful to provide information for biofilm control in oil fields. Copyright © 2015. Published by Elsevier B.V.

  1. EMISSION MEASUREMENTS OF GEOGENIC GREENHOUSE GASES IN THE AREA OF "PUSTY LAS" ABANDONED OILFIELD (POLISH OUTER CARPATHIANS

    Directory of Open Access Journals (Sweden)

    Piotr Guzy

    2017-07-01

    Full Text Available The emission of geogenic methane and carbon dioxide contributes to the world climate changes. The results of studies run worldwide demonstrate that the emission of geogenic gases strongly influences the increasing concentrations of greenhouse gases in the atmosphere, including methane and carbon dioxide. The Outer Carpathians reveal significant hydrocarbon potential and host numerous macro- and microseepages of hydrocarbons including the natural gas. Migration of hydrocarbons from deep accumulations towards the surface is controlled by diffusion and effusion. It appears that the Carpathians may play significant role as a supplier of greenhouse gases to the atmosphere.Before the World War II, oil macroseepages were the principal premises in petroleum exploration. In the Carpathians, hydrocarbons have been exploited since the XIX century. Unfortunately, most of discovered oil and gas deposits are recently only the historical objects. An example is the Sękowa-Ropica Górna-Siary oil deposit located in the marginal part of the Magura Nappe where oil has been extracted with dug wells until the mid XX century. One of such extraction sites is the "Pusty Las" oilfield. In that area, 10 methane and carbon dioxide emission measurement sites were located, among which 4 in dried dug wells and 6 in dig wells still filled with oil and/or water. Dynamics of methane and carbon dioxide concentration changes were measured with the modified static chambers method. Gas samples were collected immediately after the installation of the chamber and again, after 5 and 10 minutes. In the case of reclaimed or dry dug wells, static chamber was installed directly at the ground surface. In wells still filled with oil and/or water the chamber was equipped with an "apron" mounted on special sticks.The dynamics of concentrations changes varied from -0.871 to 119.924 ppm∙min-1 for methane and from -0.005 to 0.053 %obj∙min-1 for carbon dioxide. Average methane emission was 1

  2. Kinetics of oil-cracking for different types of marine oils from Tahe Oilfield, Tarim Basin, NW China

    Directory of Open Access Journals (Sweden)

    Anlai Ma

    2016-02-01

    Full Text Available The C1–C5 gas and carbon isotope ratios generated during the cracking of heavy, normal and high-waxy marine oils from Tahe Oilfield, Tarim Basin, NW China, using a closed-gold tube system under high pressure were presented. The three types of oil tested resulted in a similar gas-generation process. The C2–C5 range initially increased its yield with the application of pyrolysis temperature and thereafter decreased, while the C1 yield increased with the same application. High-waxy oil had the highest C1–C5 yield of 510 mg/goil, whereas heavy oil had the lowest C1–C5 yield of 316 mg/goil. The δ13C1 value was low at first, but gradually became higher as the pyrolysis temperature increased. However, the δ13C2 and δ13C3 values gradually became higher when the temperature was greater than 420 °C. The kinetic parameters of the C1–C5 gas generation for the different types of marine oils were then calculated using KINETIC software. This calculation resulted in a frequency factor of about 1.78 × 1014 s−1, while the distribution of the activation energy of the C1–C5 gas mass generated was relatively narrow with a range from 56 to 66 kcal/mol. Among the three types of oil tested, heavy oil had the widest activation energy distribution and the lowest major frequency of activation energy. The maximum temperature at which oil could be preserved as a separate oil phase varied from about 178 °C at a slow geological heating rate to 206 °C at a fast geological heating rate. This result is based on the kinetic parameters determined and in combination with the fractional conversion (C of oil to gas. Testing conducted at the volatile Middle Cambrian reservoir of well Zhongshen 1 in the Tazhong Uplift strongly supported this conclusion.

  3. Bayes multiple decision functions.

    Science.gov (United States)

    Wu, Wensong; Peña, Edsel A

    2013-01-01

    This paper deals with the problem of simultaneously making many (M) binary decisions based on one realization of a random data matrix X. M is typically large and X will usually have M rows associated with each of the M decisions to make, but for each row the data may be low dimensional. Such problems arise in many practical areas such as the biological and medical sciences, where the available dataset is from microarrays or other high-throughput technology and with the goal being to decide which among of many genes are relevant with respect to some phenotype of interest; in the engineering and reliability sciences; in astronomy; in education; and in business. A Bayesian decision-theoretic approach to this problem is implemented with the overall loss function being a cost-weighted linear combination of Type I and Type II loss functions. The class of loss functions considered allows for use of the false discovery rate (FDR), false nondiscovery rate (FNR), and missed discovery rate (MDR) in assessing the quality of decision. Through this Bayesian paradigm, the Bayes multiple decision function (BMDF) is derived and an efficient algorithm to obtain the optimal Bayes action is described. In contrast to many works in the literature where the rows of the matrix X are assumed to be stochastically independent, we allow a dependent data structure with the associations obtained through a class of frailty-induced Archimedean copulas. In particular, non-Gaussian dependent data structure, which is typical with failure-time data, can be entertained. The numerical implementation of the determination of the Bayes optimal action is facilitated through sequential Monte Carlo techniques. The theory developed could also be extended to the problem of multiple hypotheses testing, multiple classification and prediction, and high-dimensional variable selection. The proposed procedure is illustrated for the simple versus simple hypotheses setting and for the composite hypotheses setting

  4. USGS Tampa Bay Pilot Study

    Science.gov (United States)

    Yates, K.K.; Cronin, T. M.; Crane, M.; Hansen, M.; Nayeghandi, A.; Swarzenski, P.; Edgar, T.; Brooks, G.R.; Suthard, B.; Hine, A.; Locker, S.; Willard, D.A.; Hastings, D.; Flower, B.; Hollander, D.; Larson, R.A.; Smith, K.

    2007-01-01

    Many of the nation's estuaries have been environmentally stressed since the turn of the 20th century and will continue to be impacted in the future. Tampa Bay, one the Gulf of Mexico's largest estuaries, exemplifies the threats that our estuaries face (EPA Report 2001, Tampa Bay Estuary Program-Comprehensive Conservation and Management Plan (TBEP-CCMP)). More than 2 million people live in the Tampa Bay watershed, and the population constitutes to grow. Demand for freshwater resources, conversion of undeveloped areas to resident and industrial uses, increases in storm-water runoff, and increased air pollution from urban and industrial sources are some of the known human activities that impact Tampa Bay. Beginning on 2001, additional anthropogenic modifications began in Tampa Bat including construction of an underwater gas pipeline and a desalinization plant, expansion of existing ports, and increased freshwater withdrawal from three major tributaries to the bay. In January of 2001, the Tampa Bay Estuary Program (TBEP) and its partners identifies a critical need for participation from the U.S. Geological Survey (USGS) in providing multidisciplinary expertise and a regional-scale, integrated science approach to address complex scientific research issue and critical scientific information gaps that are necessary for continued restoration and preservation of Tampa Bay. Tampa Bay stakeholders identified several critical science gaps for which USGS expertise was needed (Yates et al. 2001). These critical science gaps fall under four topical categories (or system components): 1) water and sediment quality, 2) hydrodynamics, 3) geology and geomorphology, and 4) ecosystem structure and function. Scientists and resource managers participating in Tampa Bay studies recognize that it is no longer sufficient to simply examine each of these estuarine system components individually, Rather, the interrelation among system components must be understood to develop conceptual and

  5. 33 CFR 165.1195 - Regulated Navigation Area; Humboldt Bay Bar Channel and Humboldt Bay Entrance Channel, Humboldt...

    Science.gov (United States)

    2010-07-01

    ...; Humboldt Bay Bar Channel and Humboldt Bay Entrance Channel, Humboldt Bay, California. 165.1195 Section 165... Channel and Humboldt Bay Entrance Channel, Humboldt Bay, California. (a) Location. The Regulated Navigation Area (RNA) includes all navigable waters of the Humboldt Bay Bar Channel and the Humboldt Bay...

  6. Eutrophication in the Chesapeake Bay

    Science.gov (United States)

    Ulanowicz, R. E.

    1978-01-01

    The advantages and limitations of using remote sensing to acquire fast reliable data on the nutrient problem in the Chesapeake Bay ecosystem are discussed. Pollution effects to phytoplankton blooms during late summer and early fall months are also considered.

  7. FL BAY SPECTROUT-DIET

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Juvenile spotted seatrout and other sportfish are being monitored annually over a 6-mo period in Florida Bay to assess their abundance over time relative to...

  8. Missisquoi Bay Phosphorus Model Addendum

    Science.gov (United States)

    This technical memorandum provides results of an extended load reduction simulation. The memorandum serves as an addendum to the main Missisquoi Bay Phosphorus Mass Balance Model report prepared for the Lake Champlain Basin Program by LimnoTech in 2012

  9. Lavaca Bay 1985-1987

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Samples were collected from October 15, 1985 through June 12, 1987 in emergent marsh and non-vegetated habitats throughout the Lavaca Bay system to characterize...

  10. Constructing Puale Bay field camp

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Puale bay is located on the Pacific side of the Alaskan Peninsula across Shelikof Strait from the southern end of Kodiak Island. The weather, although often mild, is...

  11. Thou should not know too much. When lack of information promotes co-operative behaviour. The case of oil-fields in Wyoming, Oklahoma and Texas

    Energy Technology Data Exchange (ETDEWEB)

    Hassler, B.

    1997-12-31

    Proper assumptions of information levels are of vital importance in all kinds of analysis of interdependent decision-making. In most cases the rule is; the more information the better. In this paper, however, it is shown that such is not always the case. Lack of information can enhance resource utilisation of resources, when the problem of co-operation is of a Prisoner`s dilemma type, and when iteration of the interaction game is unlikely. The case of oil-fields in the United States has been chosen as an empirical example of the latter. Optimal drilling procedures tend to be chosen more often the less the drillers know about the resource characteristics. This outcome is explained by the structure of the decision-making problem, where low levels of information render it advantageous to choose co-operative strategies 16 refs, 4 figs

  12. Biomarker characteristics of crude oils from Ashrafi and GH oilfields in the Gulf of Suez, Egypt: An implication to source input and paleoenvironmental assessments

    Directory of Open Access Journals (Sweden)

    Mohamed M. El Nady

    2014-12-01

    Full Text Available The present work aims to evaluate the organic geochemistry of the crude oils recovered from Ashrafi and GH oilfields within the Gulf of Suez to assess and investigate oil characterization, maturation, source depositional environments and oil families. The saturated hydrocarbons were determined by gas chromatography and gas chromatography/mass spectrometry. Pristane/phytane, isoprenoids/n-alkanes, CPI, homohopane, diasteranes, gammacerane index, C29 20S/20S+20R, C29/C30 hopane and Ts/Tm are determined. The results suggest that the studied crude oils belong to marine oil and are characterized by high level of maturation and sourced mainly from organic matters of marine origin with few terrestrial inputs.

  13. Multi-criteria decision making development of ion chromatographic method for determination of inorganic anions in oilfield waters based on artificial neural networks retention model.

    Science.gov (United States)

    Stefanović, Stefica Cerjan; Bolanča, Tomislav; Luša, Melita; Ukić, Sime; Rogošić, Marko

    2012-02-24

    This paper describes the development of ad hoc methodology for determination of inorganic anions in oilfield water, since their composition often significantly differs from the average (concentration of components and/or matrix). Therefore, fast and reliable method development has to be performed in order to ensure the monitoring of desired properties under new conditions. The method development was based on computer assisted multi-criteria decision making strategy. The used criteria were: maximal value of objective functions used, maximal robustness of the separation method, minimal analysis time, and maximal retention distance between two nearest components. Artificial neural networks were used for modeling of anion retention. The reliability of developed method was extensively tested by the validation of performance characteristics. Based on validation results, the developed method shows satisfactory performance characteristics, proving the successful application of computer assisted methodology in the described case study. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Treatment of oilfield wastewater containing polymer by the batch activated sludge reactor combined with a zerovalent iron/EDTA/air system.

    Science.gov (United States)

    Lu, Mang; Wei, Xiaofang

    2011-02-01

    Laboratory-scale experiments were conducted in order to evaluate the performance of a novel treatment process for oilfield wastewater based on combining chemical oxidation, performed by a zerovalent iron (ZVI), ethylenediamine tetraacetic acid (EDTA) and air process, with biological degradation, carried out in a batch activated sludge reactor. The influence of some operating variables was studied. The results showed that the optimum pretreatment conditions were 150 mg/L EDTA, 20 g/L ZVI, and a 180-min reaction time, respectively. Under these conditions, removal efficiencies for hydrolyzed polyacrylamide (HPAM), total petroleum hydrocarbons (TPH), and chemical oxygen demand (COD) were 66%, 59%, and 45%, respectively. During the subsequent 40 h of bioremediation, the concentrations of HPAM, TPH, and COD were decreased to 10, 2 and 85 mg/L, respectively. At the end of experiments, the total removal efficiencies of HPAM, TPH, and COD were 96%, 97% and 92%, respectively. Copyright © 2010 Elsevier Ltd. All rights reserved.

  15. Radon, helium and CO{sub 2} measurements in soils overlying a former exploited oilfield, Pechelbronn district, Bas-Rhin, France

    Energy Technology Data Exchange (ETDEWEB)

    Michel-le pierres, Karine, E-mail: k.lepierres@brgm.f [BRGM, Metrology Monitoring Analysis Department, 3 Avenue Claude-Guillemin, B.P. 36009, 45060 Orleans cedex 2 (France); Gal, Frederick, E-mail: f.gal@brgm.f [BRGM, Metrology Monitoring Analysis Department, 3 Avenue Claude-Guillemin, B.P. 36009, 45060 Orleans cedex 2 (France); Brach, Michel, E-mail: m.brach@brgm.f [BRGM, Metrology Monitoring Analysis Department, 3 Avenue Claude-Guillemin, B.P. 36009, 45060 Orleans cedex 2 (France); Guignat, Stephanie, E-mail: s.guignat@brgm.f [BRGM, Regional Geological Survey, Parc Club des Tanneries, 15 Rue du Tanin, B.P. 177, 67834 Tanneries cedex (France)

    2010-10-15

    The Pechelbronn oilfield (Rhine Graben, France), where mining activity ended in the 1960s, has been used for waste disposal for twenty years. Since the wastes are varied, work is underway to identify the discharged materials and their derivatives, as well as to locate and quantify potential discharge sites. Two major goals were assigned to the present work. The first was to identify or refine the location of hidden structures that could facilitate gas emanation up to the surface, by studying soil gas concentrations (mainly {sup 222}Rn, CO{sub 2}, CH{sub 4} and helium) and carbon isotope ratios in the CO{sub 2} phase. The second was devoted to examining, from a health and safety viewpoint, if the use of the oilfield as a waste disposal site might have led to enhanced or modified gas emanation throughout the area. It appeared that CO{sub 2} and {sup 222}Rn evolution in the whole area were similar, except near some of the faults and fractures that are known through surface mapping and underground observations. These {sup 222}Rn and CO{sub 2} anomalies made it possible to highlight more emissive zones that are either related to main faults or to secondary fractures acting as migration pathways. In that sense, the CO{sub 2} phase can be used to evaluate {sup 222}Rn activities distant from tectonic structures but can lead to erroneous evaluations near to gas migration pathways. Dumping of wastes, as well as oil residues, did not appear to have a strong influence on soil gaseous species and emanation. Similarly, enhanced gas migration due to underground galleries and exploitation wells has not been established. Carbon isotope ratios suggested a balance of biological phenomena, despite the high CO{sub 2} contents reached. Other monitored gaseous species (N{sub 2}, Ar, H{sub 2} and alkanes), when detected, always showed amounts close to those found subsurface and/or in atmospheric gases.

  16. Diversity of Microbial Communities in Production and Injection Waters of Algerian Oilfields Revealed by 16S rRNA Gene Amplicon 454 Pyrosequencing.

    Directory of Open Access Journals (Sweden)

    Nesrine Lenchi

    Full Text Available The microorganisms inhabiting many petroleum reservoirs are multi-extremophiles capable of surviving in environments with high temperature, pressure and salinity. Their activity influences oil quality and they are an important reservoir of enzymes of industrial interest. To study these microbial assemblages and to assess any modifications that may be caused by industrial practices, the bacterial and archaeal communities in waters from four Algerian oilfields were described and compared. Three different types of samples were analyzed: production waters from flooded wells, production waters from non-flooded wells and injection waters used for flooding (water-bearing formations. Microbial communities of production and injection waters appeared to be significantly different. From a quantitative point of view, injection waters harbored roughly ten times more microbial cells than production waters. Bacteria dominated in injection waters, while Archaea dominated in production waters. Statistical analysis based on the relative abundance and bacterial community composition (BCC revealed significant differences between production and injection waters at both OTUs0.03 and phylum level. However, no significant difference was found between production waters from flooded and non-flooded wells, suggesting that most of the microorganisms introduced by the injection waters were unable to survive in the production waters. Furthermore, a Venn diagram generated to compare the BCC of production and injection waters of one flooded well revealed only 4% of shared bacterial OTUs. Phylogenetic analysis of bacterial sequences indicated that Alpha-, Beta- and Gammaproteobacteria were the main classes in most of the water samples. Archaeal sequences were only obtained from production wells and each well had a unique archaeal community composition, mainly belonging to Methanobacteria, Methanomicrobia, Thermoprotei and Halobacteria classes. Many of the bacterial genera

  17. BOBMEX: The Bay of Bengal Monsoon Experiment

    Digital Repository Service at National Institute of Oceanography (India)

    Bhat, G.S.; Gadgil, S.; Kumar, P.V.H.; Kalsi, S.R.; Madhusoodanan, P.; Murty, V.S.N.; Rao, C.V.K.P.; RameshBabu, V.; Rao, L.V.G.; Rao, R.R.; Ravichandran, M.; Reddy, K.G.; Rao, P.Sanjeeva; Sengupta, D.; Sikka, D.R.; Swain, J.; Vinayachandran, P.N.

    , ocean, and their interface to gain deeper insight into some of the processes that govern the variability of organized convection over the bay. Simultaneous time series observations were carried out in the northern and southern Bay of Bengal from ships...

  18. Humboldt Bay Benthic Habitats 2009 Aquatic Setting

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Humboldt Bay is the largest estuary in California north of San Francisco Bay and represents a significant resource for the north coast region. Beginning in 2007 the...

  19. Humboldt Bay, California Benthic Habitats 2009 Geoform

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Humboldt Bay is the largest estuary in California north of San Francisco Bay and represents a significant resource for the north coast region. Beginning in 2007 the...

  20. Humboldt Bay, California Benthic Habitats 2009 Biotic

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Humboldt Bay is the largest estuary in California north of San Francisco Bay and represents a significant resource for the north coast region. Beginning in 2007 the...

  1. Humboldt Bay, California Benthic Habitats 2009 Geodatabase

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Humboldt Bay is the largest estuary in California north of San Francisco Bay and represents a significant resource for the north coast region. Beginning in 2007 the...

  2. 77 FR 57107 - Bandon Marsh, Nestucca Bay, and Siletz Bay National Wildlife Refuges, Coos, Tillamook, and...

    Science.gov (United States)

    2012-09-17

    ... Fish and Wildlife Service Bandon Marsh, Nestucca Bay, and Siletz Bay National Wildlife Refuges, Coos... conservation plans and environmental assessments (Draft CCP/EAs) for three Oregon refuges-- Bandon Marsh... . Include ``Bandon Marsh, Nestucca Bay, and Siletz Bay draft CCP and EA'' in the subject line of the message...

  3. 33 CFR 100.112 - Swim the Bay, Narragansett Bay, Narragansett, RI.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Swim the Bay, Narragansett Bay, Narragansett, RI. 100.112 Section 100.112 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND..., Narragansett Bay, Narragansett, RI. (a) Regulated area. All waters of the East Passage of Narragansett Bay...

  4. 77 FR 70891 - Safety Zone; Bay Bridge Construction, San Francisco Bay, San Francisco, CA

    Science.gov (United States)

    2012-11-28

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Bay Bridge Construction, San Francisco Bay..., CA in support of the Bay Bridge Construction Safety Zone from November 1, 2012 through July 31, 2013.... 1221 et seq.). CALTRANS will sponsor the Bay Bridge Construction Safety Zone on November 1, 2012...

  5. Bayes linear statistics, theory & methods

    CERN Document Server

    Goldstein, Michael

    2007-01-01

    Bayesian methods combine information available from data with any prior information available from expert knowledge. The Bayes linear approach follows this path, offering a quantitative structure for expressing beliefs, and systematic methods for adjusting these beliefs, given observational data. The methodology differs from the full Bayesian methodology in that it establishes simpler approaches to belief specification and analysis based around expectation judgements. Bayes Linear Statistics presents an authoritative account of this approach, explaining the foundations, theory, methodology, and practicalities of this important field. The text provides a thorough coverage of Bayes linear analysis, from the development of the basic language to the collection of algebraic results needed for efficient implementation, with detailed practical examples. The book covers:The importance of partial prior specifications for complex problems where it is difficult to supply a meaningful full prior probability specification...

  6. Contaminant transport in Massachusetts Bay

    Science.gov (United States)

    Butman, Bradford

    Construction of a new treatment plant and outfall to clean up Boston Harbor is currently one of the world's largest public works projects, costing about $4 billion. There is concern about the long-term impact of contaminants on Massachusetts Bay and adjacent Gulf of Maine because these areas are used extensively for transportation, recreation, fishing, and tourism, as well as waste disposal. Public concern also focuses on Stellwagen Bank, located on the eastern side of Massachusetts Bay, which is an important habitat for endangered whales. Contaminants reach Massachusetts Bay not only from Boston Harbor, but from other coastal communities on the Gulf of Maine, as well as from the atmosphere. Knowledge of the pathways, mechanisms, and rates at which pollutants are transported throughout these coastal environments is needed to address a wide range of management questions.

  7. Hierarchical mixtures of naive Bayes classifiers

    OpenAIRE

    Wiering, M.A.

    2002-01-01

    Naive Bayes classifiers tend to perform very well on a large number of problem domains, although their representation power is quite limited compared to more sophisticated machine learning algorithms. In this pa- per we study combining multiple naive Bayes classifiers by using the hierar- chical mixtures of experts system. This system, which we call hierarchical mixtures of naive Bayes classifiers, is compared to a simple naive Bayes classifier and to using bagging and boosting for combining ...

  8. Backscatter imagery in Jobos Bay

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a 1x1 meter resolution backscatter mosaic of Jobos Bay, Puerto Rico (in NAD83 UTM 19 North). The backscatter values are in relative 8-bit (0 –...

  9. Classification using Hierarchical Naive Bayes models

    DEFF Research Database (Denmark)

    Langseth, Helge; Dyhre Nielsen, Thomas

    2006-01-01

    Classification problems have a long history in the machine learning literature. One of the simplest, and yet most consistently well-performing set of classifiers is the Naïve Bayes models. However, an inherent problem with these classifiers is the assumption that all attributes used to describe......, termed Hierarchical Naïve Bayes models. Hierarchical Naïve Bayes models extend the modeling flexibility of Naïve Bayes models by introducing latent variables to relax some of the independence statements in these models. We propose a simple algorithm for learning Hierarchical Naïve Bayes models...

  10. Microbial communities inhabiting oil-contaminated soils from two major oilfields in Northern China: Implications for active petroleum-degrading capacity.

    Science.gov (United States)

    Sun, Weimin; Dong, Yiran; Gao, Pin; Fu, Meiyan; Ta, Kaiwen; Li, Jiwei

    2015-06-01

    Although oilfields harbor a wide diversity of microorganisms with various metabolic potentials, our current knowledge about oil-degrading bacteria is limited because the vast majority of oil-degrading bacteria remain uncultured. In the present study, microbial communities in nine oil-contaminated soils collected from Daqing and Changqing, two of the largest oil fields in China, were characterized through highthroughput sequencing of 16S rRNA genes. Bacteria related to the phyla Proteobacteria and Actinobacteria were dominant in four and three samples, respectively. At the genus level, Alkanindiges, Arthrobacter, Pseudomonas, Mycobacterium, and Rhodococcus were frequently detected in nine soil samples. Many of the dominant genera were phylogenetically related to the known oil-degrading species. The correlation between physiochemical parameters within the microbial communities was also investigated. Canonical correspondence analysis revealed that soil moisture, nitrate, TOC, and pH had an important impact in shaping the microbial communities of the hydrocarbon-contaminated soil. This study provided an in-depth analysis of microbial communities in oilcontaminated soil and useful information for future bioremediation of oil contamination.

  11. Treatment of oilfield produced water using Fe/C micro-electrolysis assisted by zero-valent copper and zero-valent aluminium.

    Science.gov (United States)

    Zhang, Qi

    2015-01-01

    In this study, the Fe/Cu/C and Fe/Al/C inner micro-electrolysis systems were used to treat actual oilfield produced water to evaluate the feasibility of the technology. Effects of reaction time, pH value, the dosage of metals and activated carbon, and Fe:C mass ratio on the treatment efficiency of wastewater were studied. The results showed that the optimum conditions were reaction time 120 min, initial solution pH 4.0, Fe dosage 13.3 g/L, activated carbon dosage 6.7 g/L, Cu dosage 2.0 g/L or Al dosage 1.0 g/L. Under the optimum conditions, the removal efficiencies of chemical oxygen demand (COD) were 39.3%, 49.7% and 52.6% in the Fe/C, Fe/Cu/C and Fe/Al/C processes, respectively. Meanwhile, the ratio of five-day biochemical oxygen demand to COD was raised from 0.18 to above 0.35, which created favourable conditions for the subsequent biological treatment. All these led to an easy maintenance and low operational cost.

  12. Multiphase Calcite Cementation and Fluids Evolution of a Deeply Buried Carbonate Reservoir in the Upper Ordovician Lianglitag Formation, Tahe Oilfield, Tarim Basin, NW China

    Directory of Open Access Journals (Sweden)

    Jiaqing Liu

    2017-01-01

    Full Text Available Oil and gas have been found in the Upper Ordovician Lianglitag Formation carbonates in the Tahe Oilfield, Tarim Basin, NW China. This study documents the origin of diagenetic fluids by using a combination of petrology, SIMS, fluid inclusion, and radiogenic isotope analysis. Six stages of calcite cements were revealed. C1-C2 formed in marine to early burial environments. C3 has relatively low δ18OVPDB values (−8.45‰ to −6.50‰ and likely has a meteoric origin. Meteoric water probably fluxed into aquifers during the Early Paleozoic and Late Paleozoic uplift. C4 has δ18OVPDB values typically 3‰ higher than those of C3, and probably formed during shallow burial. C5 displays relatively negative δ18OVPDB values (−8.26‰ to −5.12‰, and the moderate-to-high fluid-inclusion temperatures imply that it precipitated in burial environments. C6 shows homogenization temperatures (up to 200°C higher than the maximum burial and much lower salinities (<10.61 wt% NaCl, which may suggest that the fluid was deeply recycled meteoric water. The average 87Sr/86Sr ratios of fracture- and vug-filling calcite cements are much higher, indicative of incorporation of radiogenic Sr. Caves and fractures constitute the dominant reservoir spaces. A corresponding diagenesis-related reservoir evolution model was established that favors exploration and prediction.

  13. Evaluations of Radionuclides of Uranium, Thorium, and Radium Associated with Produced Fluids, Precipitates, and Sludges from Oil, Gas, and Oilfield Brine Injection Wells in Mississippi

    Energy Technology Data Exchange (ETDEWEB)

    Ericksen, R.L.

    1999-10-28

    There is an unsurpassed lack of scientific data with respect to the concentrations and isotopic compositions of uranium, thorium, and radium in the produced formation fluids (brine), precipitates, and sludges generated with the operation of oil and gas wells in Mississippi. These radioactive elements when contained in the formation fluids have been given the term NORM, which is an acronym for naturally occurring radioactive materials. When they are technologically enhanced during oil and gas production activities resulting in the formation of scale (precipitates) and sludges they are termed TENORM (technologically enhanced naturally occurring radioactive materials). As used in this document, NORM and TENORM will be considered equivalent terms and the occurrence of NORM in the oilfield will be considered the result of production operations. As a result of the lack of data no scientifically sound theses may be developed concerning the presence of these radionuclides in the fluid brine, precipitate (scale), or sludge phases. Over the period of just one year, 1997 for example, Mississippi produced over 39,372,963,584 liters (10,402,368,186 gallons or 247,675,433 barrels) of formation water associated with hydrocarbon production from 41 counties across the state.

  14. Passive Layer Stability of 2205 Duplex Stainless Steel in Oilfield-Produced Water: Potentiostatic Critical Pitting Temperature Test and Wavelet Analysis

    Science.gov (United States)

    Sabouri, M.; Hoseiny, H.

    2017-08-01

    In this article, the potentiostatic passivation behavior of 2205 duplex stainless steel was investigated in oilfield-produced water with a focus on the variation of the passive layer stability with temperature. The obtained current-time transients were analyzed using wavelet transform to evaluate the passive layer deterioration at different time domains corresponding to the temperatures of 303 K, 313 K, 323 K, and 333 K (30 °C, 40 °C, 50 °C, and 60 °C). The results showed that the critical pitting temperature (CPT) of the 2205 alloy in the studied produced water was 333.2 K (60.2 °C). In addition, the optimum passivation of the material surface was obtained between 303 K and 313 K (30 °C and 40 °C). The passive layer deteriorated at about 323 K (50 °C) by penetration of chloride and subsequently entered into the transpassive region. Moreover, at 333 K (60 °C), the metastable pits converted to permanent or overlapped pits. Corrosion morphology confirmed the results obtained by wavelet analyses. In addition, microscopical studies of the alloy microstructure showed that both phases, i.e., austenite and ferrite, were attacked by corrosion, although it was more severe in ferrite.

  15. Combining stable carbon isotope analysis and petroleum-fingerprinting to evaluate petroleum contamination in the Yanchang oilfield located on loess plateau in China.

    Science.gov (United States)

    Wang, Yiping; Liang, Jidong; Wang, Jinxing; Gao, Sha

    2018-01-01

    This study evaluated petroleum contamination in the Yanchang (Shaanxi Yanchang Petroleum (Group) Co., Ltd.) oilfield, located in the loess plateau region of northern Shaanxi, China. Surface soil and sediment samples were collected from the wasteland, farmland, and riverbed in this area to assess the following parameters: total petroleum hydrocarbon (TPH), n-alkanes, polycyclic aromatic hydrocarbons (PAHs), and carbon isotope ratios (δ13C). The results showed that TPH and PAH levels in the study area were 907-3447 mg/kg and 103.59-563.50 μg/kg, respectively, significantly higher than the control samples (TPH 224 mg/kg, PAHs below method quantification limit, MQL). Tests using δ13C to detect modified TPH (2238.66 to 6639.42 mg/kg) in the wastelands adjacent to the oil wells revealed more significant contamination than tests using extraction gravimetric analysis. In addition, "chemical fingerprint" indicators, such as low to high molecular weight (LMW/HMW) hydrocarbons, carbon preference index (CPI), and pristine/phytane (Pr/Ph), further confirmed the presence of heavy petroleum contamination and weathering. This has resulted in a nutrient imbalance and unsuitable pH and moisture conditions for microbial metabolic activities. This study evaluates petroleum contamination, which can inform contamination remediation on a case by case basis.

  16. The Chesapeake Bay impact structure

    Science.gov (United States)

    Powars, David S.; Edwards, Lucy E.; Gohn, Gregory S.; Horton, J. Wright

    2015-10-28

    About 35 million years ago, during late Eocene time, a 2-mile-wide asteroid or comet smashed into Earth in what is now the lower Chesapeake Bay in Virginia. The oceanic impact vaporized, melted, fractured, and (or) displaced the target rocks and sediments and sent billions of tons of water, sediments, and rocks into the air. Glassy particles of solidified melt rock rained down as far away as Texas and the Caribbean. Models suggest that even up to 50 miles away the velocity of the intensely hot air blast was greater than 1,500 miles per hour, and ground shaking was equivalent to an earthquake greater than magnitude 8.0 on the Richter scale. Large tsunamis affected most of the North Atlantic basin. The Chesapeake Bay impact structure is among the 20 largest known impact structures on Earth.

  17. Bayes reconstruction of missing teeth

    DEFF Research Database (Denmark)

    Sporring, Jon; Jensen, Katrine Hommelhoff

    2008-01-01

     We propose a method for restoring the surface of tooth crowns in a 3D model of a human denture, so that the pose and anatomical features of the tooth will work well for chewing. This is achieved by including information about the position and anatomy of the other teeth in the mouth. Our system...... contains two major parts: A statistical model of a selection of tooth shapes and a reconstruction of missing data. We use a training set consisting of 3D scans of dental cast models obtained with a laser scanner, and we have build a model of the shape variability of the teeth, their neighbors...... regularization of the log-likelihood estimate based on differential geometrical properties of teeth surfaces, and we show general conditions under which this may be considered a Bayes prior.Finally we use Bayes method to propose the reconstruction of missing data, for e.g. finding the most probable shape...

  18. Influenza in Bristol Bay, 1919

    OpenAIRE

    Maria Gilson deValpine

    2015-01-01

    The 1918 influenza pandemic has been blamed for as many as 50 million deaths worldwide. Like all major disasters, the full story of the pandemic includes smaller, less noted episodes that have not attracted historical attention. The story of the 1919 wave of the influenza pandemic in Bristol Bay Alaska is one such lost episode. It is an important story because the most accessible accounts—the Congressional Record and t...

  19. Zooplankton Biomass Data from Prince William Sound, Icy Bay and Yakutat Bay, Alaska 2010-2011

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset includes zooplankton biomass from Prince William Sound, Icy Bay and Yakutat Bay, Alaska. Zooplankton were sampled with a ring net (0.6 m diameter with...

  20. [Characteristics of Pahs pollution in sediments from Leizhou coastal marine area, Liusha Bay and Shenzhen Bay].

    Science.gov (United States)

    Zhao, Li-Rong; Sun, Sheng-Li; Ke, Sheng

    2012-04-01

    Leizhou coastal marine area, Liusha Bay and Shenzhen Bay represented open coastal area and half-closed bay, respectively. This study discussed the differences of PAHs concentration levels, spatial distribution and sources in sediments from these three marine areas. The results showed that detected ratios of 15 PAHs were 100%, and major compounds were 3-ring and 4-ring PAHs, especialy Phe, Fla, Pry and Bbf; Sigma PAHs concentration was Leizhou the outside, and the aquaculture > the non-aquaculture in Liusha Bay and Shenzhen Bay. It suggested that large-scale mariculture inside bay played an important role in PAHs pollution and might make it serious. Oil, fossil fuels and biomass burning were the dominant sources of PAHs in sediments from Leizhou coastal area, Liusha Bay and Shenzhen Bay.

  1. Linear dimension reduction and Bayes classification

    Science.gov (United States)

    Decell, H. P., Jr.; Odell, P. L.; Coberly, W. A.

    1978-01-01

    An explicit expression for a compression matrix T of smallest possible left dimension K consistent with preserving the n variate normal Bayes assignment of X to a given one of a finite number of populations and the K variate Bayes assignment of TX to that population was developed. The Bayes population assignment of X and TX were shown to be equivalent for a compression matrix T explicitly calculated as a function of the means and covariances of the given populations.

  2. Investigation of Tidal Power, Cobscook Bay, Maine.

    Science.gov (United States)

    1980-08-01

    include Perry, Pembrook, Edmunds, Dennyville, Whiting and Trescott (See Figure 1). Located entirely in the United States at the mouth of the Bay of Fundy ...Quoddy Region because of the softer sediments in that area. Some are harvested within the bay itself, although to a much lesser extent. Lobsters are...earthquake of an intensity VIII occurring in the Bay of Fundy approximately 35 miles west of the site. Closer to the site an earthquake of intensity VII

  3. 78 FR 45061 - Safety Zone; Sister Bay Marina Fest Fireworks and Ski Show, Sister Bay, WI

    Science.gov (United States)

    2013-07-26

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Sister Bay Marina Fest Fireworks and Ski... intended to restrict vessels from a portion of Sister Bay due to a fireworks display and ski show. This... with the fireworks display and ski show in Sister Bay on August 31, 2013. DATES: This rule is effective...

  4. 78 FR 46813 - Safety Zone; Evening on the Bay Fireworks; Sturgeon Bay, WI

    Science.gov (United States)

    2013-08-02

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Evening on the Bay Fireworks; Sturgeon Bay... of Sturgeon Bay due to a fireworks display. This temporary safety zone is necessary to protect the surrounding public and vessels from the hazards associated with the fireworks display. DATES: This rule is...

  5. The Schoonebeek Oilfield: the Rw-2e High Pressure Steam Injection Project Gisement de Schoonebeek : le projet RW-2E d'injection de vapeur à haute pression

    Directory of Open Access Journals (Sweden)

    Holtam V. R.

    2006-11-01

    Full Text Available The daily oil production from the Schoonebeek Oilfield amounts to some 1400 m3 /d, of which ca. 65% is produced from a high pressure (85 bar steam injection project. This project was started in 1981 and originally consisted of 7 structurally downdip/middip steam injectors. However, following the initially somewhat disappointing project performance, steam injection was moved to 4 middip/ updip injectors in 1984. This change in the location of the steam injectors, together with an increase in the level of surveillance and a more pragmatic reservoir management policy, has resulted in improved project performance. The ultimate extra oil/steam ratio for the total project is now expected to be 0. 7 m3 oil/ton of steam injected. La production de pétrole du gisement de Schoonebeek est d'environ 1400 m3/jour, dont près de 65% sont obtenus par injection de vapeur à haute pression (85 bar. Ce projet lancé en 1981 comportait initialement 7 injecteurs de vapeur orientés vers l'aval-pendage. En raison de performances décevantes, l'injection de vapeur a été transférée en 1984 sur 4 injecteurs travaillant vers l'amont-pendage. Ce changement de position des injecteurs, accompagné d'une surveillance renforcée et d'une politique de gestion du gisement plus pragmatique, a donné des résultats favorables. On pense que le rapport pétrole/vapeur pour l'ensemble du projet devrait être en dernière analyse de 0,7 m3 de pétrole par tonne de vapeur injectée.

  6. An integrated approach for determination of pore-type distribution in carbonate-siliciclastic Asmari Reservoir, Cheshmeh-Khosh Oilfield, SW Iran

    Science.gov (United States)

    Gharechelou, Sajjad; Amini, Abdolhossein; Kadkhodaie-Ilkhchi, Ali; Moradi, Babak

    2015-10-01

    This paper presents an integrated pore type study at microscopic (core data), mesoscopic (well logs) and megascopic scales (3D seismic data) in the mixed carbonate-siliciclastic Asmari Reservoir of the Cheshmeh-Khosh Oilfield, SW Iran. Firstly, pore types are determined in a microscopic scale based on petrographic studies of thin sections. Well logs and nuclear magnetic resonance (NMR) log data are employed for pore type determination based on a velocity deviation log (mesoscopic scale). For each pore type subclass, a suite of physical rock properties including average poroperm values, T2 distribution, capillary pressure, pore size distribution and depositional texture are calculated. For this purpose, the NMR log, mercury injection capillary pressure data and core descriptions are interpreted in an integrated approach. Capillary pressure and pore size distribution in each pore type class are determined by mercury injection capillary pressure tests and synthesis of a continuous capillary pressure log from the NMR log (pseudo Pc curves). For dynamic behavior examination of the reservoir, the pore types are analysed in the framework of hydraulic flow units. Finally, 3D post-stacked seismic data are converted to a cube of pore types based on acoustic impedance inversion and seismic attributes. The methodology of this study is accomplished by using core and log data from three key wells and a 3D post-stack seismic data from the studied field. Lastly, a map of pore type distribution is established to provide a clue on the high and low permeable zones of the field. The presented methodology signifies reservoir anatomy on micro to mega scales.

  7. Radiological exposure assessment from soil, underground and surface water in communities along the coast of a shallow water offshore oilfield in Ghana.

    Science.gov (United States)

    Kpeglo, D O; Mantero, J; Darko, E O; Emi-Reynolds, G; Akaho, E H K; Faanu, A; Garcia-Tenorio, R

    2015-02-01

    Radiometric determinations have been carried out to assess public exposure to radioactivity for communities along the coast of a shallow water offshore oilfield in Ghana (which started their operations recently) in order to establish baseline data using alpha spectrometry after radiochemical separation and non-destructive gamma spectrometry. The average activity concentrations of (234)U, (238)U, (230)Th and (232)Th by alpha-particle spectrometry and of (226)Ra, (228)Ra, (228)Th, (40)K, (210)Pb, (234)Th and (137)Cs by gamma-ray spectrometry were determined in the soil samples. The activity concentrations of (234)U, (238)U, (230)Th and (232)Th were determined in the water samples by alpha-particle spectrometry and of (226)Ra by liquid scintillation counting. The total annual effective dose to the public was estimated from the measured activity concentrations and this was clearly below the International Commission on Radiological Protection (ICRP) reference level of 1 mSv y(-1) for public exposure control. In addition, the estimated values of Raeq, Hex and Hin were all lower than the recommended acceptable values and the mean values of gross alpha and gross beta determinations performed for all the water samples give values that were all below the Ghana Standards Authority and World Health Organization recommended guideline values for drinking water quality. The results obtained show insignificant public exposure to radioactivity. However, this study provides important information for future studies on subsequent evaluations of the possible future environmental contamination due to activities of the oil industry in Ghana. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. Investigation of Tidal Power, Cobscook Bay, Maine. Environmental Appendix.

    Science.gov (United States)

    1980-08-01

    Nevertheless, some worms are harvested in Cobscook Bay . Lobsters are also found in Cobscook Bay , although not in sufficient numbers to support a...ring-billed gull, sanderling, black-bellied plover, semipalmated plover, least sandpiper and dowitcher. Cobscook Bay (and Bay of Fundy in general...tidal power development in the upper Bay of Fundy . Circulation between Cobscook Bay and the Gulf of Maine will be reduced resulting in decreased

  9. Galveston Bay Area : Land Barrier preliminary design

    NARCIS (Netherlands)

    van Berchum, E.C.; de Vries, P.A.L.; de Kort, R.P.J.

    2016-01-01

    The Galveston Bay Area is under significant risk from hurricane induced flooding. Ever since Hurricane Ike caused billions of damage back in 2008, the option of closing off the Galveston Bay from the Gulf of Mexico was investigated. This report, commissioned by Texas A&M University in Galveston,

  10. Unique thermal record in False Bay

    CSIR Research Space (South Africa)

    Grundlingh, ML

    1993-10-01

    Full Text Available Over the past decade False Bay has assumed a prime position in terms of research in to large South African bays. This is manifested by investigations that cover flow conditions modelling, thermal structure, management, biology and nutrients, geology...

  11. Hierarchical mixtures of naive Bayes classifiers

    NARCIS (Netherlands)

    Wiering, M.A.

    2002-01-01

    Naive Bayes classifiers tend to perform very well on a large number of problem domains, although their representation power is quite limited compared to more sophisticated machine learning algorithms. In this pa- per we study combining multiple naive Bayes classifiers by using the hierar- chical

  12. Traditional Fisheries of Antongil Bay, Madagascar | Doukakis ...

    African Journals Online (AJOL)

    Madagascar's marine fisheries provide revenue and sustenance for the island nation. Antongil Bay, the largest shallow-water bay along Madagascar's eastern coast, harbors significant marine resources and is heavily utilized by traditional, artisanal (shark-fin) and industrial fisheries. Mean hourly catch rates are just under 1 ...

  13. Recent Results from Daya Bay

    CERN Document Server

    Zhan, Liang

    2015-01-01

    The Daya Bay reactor neutrino experiment observed electron antineutrino disappearance associated with $\\theta_{13}$ with a significance better than $5\\sigma$ in 2012. The final two of eight antineutrino detectors were installed in the summer of 2012. Including the 404 days of data collected with the full detector configuration resulted in a 3.6 times increase of statistics over the previous result with the 6-AD configuration. With improvements of the systematic uncertainties and better estimation of backgrounds, Daya Bay has measured $\\sin^22\\theta_{13} = 0.084\\pm0.005$ and $|\\Delta m^2_{ee}|=2.42^{+0.10}_{-0.11}\\times 10^{-3}$~eV$^2$. This is the most precise measurement of $\\sin^22\\theta_{13}$ to date and the most precise measurement of of $|\\Delta m^2_{ee}|$ via electron antineutrino disappearance. Several other analysis results are presented, including an independent measurement of $\\theta_{13}$ using inverse-beta decays associated with neutron capture on hydrogen, a measurement of reactor antineutrino fl...

  14. Use of Remote Sensing Data and GIS Tools for Seismic Hazard Assessment for Shallow Oilfields and its Impact on the Settlements at Masjed-i-Soleiman Area, Zagros Mountains, Iran

    Directory of Open Access Journals (Sweden)

    Hojjat Ollah Safari

    2010-05-01

    Full Text Available Masjed-i-Soleiman (MIS is situated in the northern part of the Dezful embayment, which is in the Zagros fold–thrust belt with high seismic activities. MIS faces a shallow buried anticline, formed by the shallowest oilfield with a thick gas cap. The cap rocks of this oilfield are highly fractured, which has resulted in leakages from the gas cap. In this paper, we have used remote sensing techniques and image interpretation for the identification of the Niayesh, Lahbari, Andika and MIS fault zones in the studied area. Further, the study exploited seismic potential mapping using the remote sensing techniques. The relationships between the structural controls and localized gas leakage are assessed within the GIS environment. Additionally, field observation data corroborated that the leakages (and seepages are smashed within the intersection of Niayesh and MIS fault zone, which belongs to the high fractured hinge zone of the MIS anticline. As a result, the reactivation of these active faults may cause large earthquakes with a maximum magnitude of between 6.23 < Ms < 7.05 (Richter scale and maximum horizontal acceleration 0.26 < a < 0.55 g. Finally, the authors concluded that this anticipated earthquake may cause large scale fracturing of cap rocks, releasing a large volume of H2S gas from the uppermost layer of the reservoir.

  15. 19 CFR 7.11 - Guantanamo Bay Naval Station.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Guantanamo Bay Naval Station. 7.11 Section 7.11... TREASURY CUSTOMS RELATIONS WITH INSULAR POSSESSIONS AND GUANTANAMO BAY NAVAL STATION § 7.11 Guantanamo Bay Naval Station. Articles of foreign origin may enter the area (both land and water) of the Guantanamo Bay...

  16. An Evaluation of Sea Ice Deformation and Its Spatial Characteristics from the Regional Arctic System Model

    Science.gov (United States)

    2012-12-01

    ANWR, was not included in the act. Upon discovery of oil in Prudhoe Bay in 1968, the U.S. government began plans to build an oil pipeline from Prudhoe...J.A. Richter-Menge, 2010: Influences of the ocean surface mixed layer and thermohaline stratification on Arctic sea ice in the central Canada Basin

  17. THz identification and Bayes modeling

    Science.gov (United States)

    Sokolnikov, Andre

    2017-05-01

    THz Identification is a developing technology. Sensing in the THz range potentially gives opportunity for short range radar sensing because THz waves can better penetrate through obscured atmosphere, such as fog, than visible light. The lower scattering of THz as opposed to the visible light results also in significantly better imaging than in IR spectrum. A much higher contrast can be achieved in medical trans-illumination applications than with X-rays or visible light. The same THz radiation qualities produce better tomographical images from hard surfaces, e.g. ceramics. This effect comes from the delay in time of reflected THz pulses detection. For special or commercial applications alike, the industrial quality control of defects is facilitated with a lower cost. The effectiveness of THz wave measurements is increased with computational methods. One of them is Bayes modeling. Examples of this kind of mathematical modeling are considered.

  18. A pollution history of Chesapeake Bay

    Science.gov (United States)

    Goldberg, E.D.; Hodge, V.; Koide, M.; Griffin, J.; Gamble, E.; Bricker, O.P.; Matisoff, G.; Holdren, G.R.; Braun, R.

    1978-01-01

    Present day anthropogenic fluxes of some heavy metals to central Chesapeake Bay appear to be intermediate to those of the southern California coastal region and those of Narragansett Bay. The natural fluxes, however, are in general higher. On the bases of Pb-210 and Pu-239 + 240 geochronologies and of the time changes in interstitial water compositions, there is a mixing of the upper 30 or so centimeters of the sediments in the mid-Chesapeake Bay area through bioturbation by burrowing mollusks and polychaetes. Coal, coke and charcoal levels reach one percent or more by dry weight in the deposits, primarily as a consequence of coal mining operations. ?? 1978.

  19. 78 FR 14185 - Safety Zone; MODU KULLUK; Kiliuda Bay, Kodiak Island, AK to Captains Bay, Unalaska Island, AK

    Science.gov (United States)

    2013-03-05

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; MODU KULLUK; Kiliuda Bay, Kodiak Island, AK to Captains Bay, Unalaska Island, AK AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY... in Kiliuda Bay, Kodiak Island, Alaska with planned towed transit into Captains Bay, Unalaska Island...

  20. 46 CFR 7.20 - Nantucket Sound, Vineyard Sound, Buzzards Bay, Narragansett Bay, MA, Block Island Sound and...

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Nantucket Sound, Vineyard Sound, Buzzards Bay, Narragansett Bay, MA, Block Island Sound and easterly entrance to Long Island Sound, NY. 7.20 Section 7.20... Atlantic Coast § 7.20 Nantucket Sound, Vineyard Sound, Buzzards Bay, Narragansett Bay, MA, Block Island...

  1. Geometry, kinematics and dynamic characteristics of a compound transfer zone: the Dongying anticline, Bohai Bay Basin, eastern China

    Directory of Open Access Journals (Sweden)

    Tian Fei

    2016-01-01

    Full Text Available The Dongying anticline is an E-W striking complex fault-bounded block unit which located in the central Dongying Depression, Bohai Bay Basin. The anticline covers an area of approximately 12 km2. The overlying succession, which is mainly composed of Tertiary strata, is cut by normal faults with opposing dips. In terms of the general structure, the study area is located in a compound transfer zone with major bounding faults to the west (Ying 1 fault and east (Ying -8 and -31 faults. Using three-dimensional seismic data, wireline log and checkshot data, the geometries and kinematics of faults in the transfer zone were studied, and fault displacements were calculated. The results show that when activity on the Ying 1 fault diminished, displacement was transferred to the Ying -8, Ying -31 and secondary faults so that total displacement increased. Dynamic analysis shows that the stress fields in the transfer zone were complex: the northern portion was a left-lateral extensional shear zone, and the southern portion was a right-lateral extensional shear zone. A model of potential hydrocarbon traps in the Dongying transfer zone was constructed based on the above data combined with the observed reservoir rock distribution and the sealing characteristics of the faults. The hydrocarbons were mainly expulsed from Minfeng Sag during deposition periods of Neogene Guantao and Minghuazhen Formations, and migrated along major faults from source kitchens to reservoirs. The secondary faults acted as barriers, resulting in the formation of fault-bound compartments. The high points of the anticline and well-sealed traps near secondary faults are potential targets. This paper provides a reservoir formation model of the low-order transfer zone and can be applied to the hydrocarbon exploration in transfer zones, especially the complex fault block oilfields in eastern China.

  2. Description of gravity cores from San Pablo Bay and Carquinez Strait, San Francisco Bay, California

    Science.gov (United States)

    Woodrow, Donald L.; John L. Chin,; Wong, Florence L.; Fregoso, Theresa; Jaffe, Bruce E.

    2017-06-27

    Seventy-two gravity cores were collected by the U.S. Geological Survey in 1990, 1991, and 2000 from San Pablo Bay and Carquinez Strait, California. The gravity cores collected within San Pablo Bay contain bioturbated laminated silts and sandy clays, whole and broken bivalve shells (mostly mussels), fossil tube structures, and fine-grained plant or wood fragments. Gravity cores from the channel wall of Carquinez Strait east of San Pablo Bay consist of sand and clay layers, whole and broken bivalve shells (less than in San Pablo Bay), trace fossil tubes, and minute fragments of plant material.

  3. FL BAY SPECTROUT-POPULATION STATUS

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Juvenile spotted seatrout and other sportfish are being monitored annually over a 6-mo period in Florida Bay to assess their abundance over time relative to...

  4. Watermass structure in the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Sastry, J.S.; Rao, D.P.; Murty, V.S.N.; Sarma, Y.V.B.; Suryanarayana, A.; Babu, M.T.

    The distributions of temperature, salinity thermosteric anomaly, density flux function and stability along 88 degrees E in the Bay of Bengal are presented. The surface salinities showed strong gradients both horizontally and vertically in northern...

  5. Delaware River and Upper Bay Sediment Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The area of coverage consists of 192 square miles of benthic habitat mapped from 2005 to 2007 in the Delaware River and Upper Delaware Bay. The bottom sediment map...

  6. Underwater Video Sites in Jobos Bay

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Shallow-water (<30m) benthic habitat maps of the nearshore marine environment of Jobos Bay, Puerto Rico were mapped and characterized using visual interpretation...

  7. San Antonio Bay 1986-1989

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The effect of salinity on utilization of shallow-water nursery habitats by aquatic fauna was assessed in San Antonio Bay, Texas. Overall, 272 samples were collected...

  8. BENTHIC MACROFAUNAL ALIENS IN WILLAPA BAY

    Science.gov (United States)

    Benthic macrofaunal samples were collected at random stations in Willapa Bay, WA, in four habitats [eelgrass (Zostera marina), Atlantic cordgrass (Spartina alterniflora), mud shrimp (Upogebia pugettensis), ghost shrimp (Neotrypaea californiensis)] in 1996 and in seven habitats (Z...

  9. Bay Scallop Spawning, Survival, Growth Records

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bay Scallops are selected and cultured according to criteria of growth and survival. Morphological attributes have also been selected to assess heretibility....

  10. Mesozoic anomalies in the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Ramana, M.V.; Nair, R.R.; Sarma, K.V.L.N.S.; Ramprasad, T.; Krishna, K.S.; Subrahmanyam, V.; D'Cruz, M.; Subrahmanyam, C.; Paul, J.; Subrahmanyam, A.S.; Sekhar, D.V.C.

    The analysis of 8200 line km of total magnetic intensity data in the Bay of Bengal, northeastern Indian Ocean, revealed the presence of approximately N30~'E-trending seafloor spreading type magnetic anomalies. These anomalies resemble the Mesozoic...

  11. Hydrogeomorphic Regions in the Chesapeake Bay Watershed.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Generalized lithology (rock type) and physiography based on geologic formations were used to characterize hydrgeomorphic regions (HGMR) within the Chesapeake Bay...

  12. 2002 Willapa Bay LiDAR Project

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA contracted with Spencer B. Gross, Inc. (SBG) to obtain airborne LiDAR of Willapa Bay, Washington during low tide conditions. The LiDAR data was processed to...

  13. Corpus ChristiEast Matagorda Bay 1986

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Patterns of habitat utilization were compared among transplanted and natural Spartina alterniflora marshes in the Halls Lake area of Chocolate Bay in the Galveston...

  14. 2004 Saginaw Bay, Lake Huron, Michigan Lidar

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This metadata document describes the collection and processing of Light Detection and Ranging (LIDAR) data over an area along the coast of Saginaw Bay, Lake Huron,...

  15. Willapa Bay, Washington Benthic Habitats 1995 Biotic

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In June 1995, the Columbia River Estuary Study Taskforce (CREST) acquired 295 true color aerial photographs (1:12,000) of Willapa Bay, Washington, from the State of...

  16. Willapa Bay, Washington Benthic Habitats 1995 Geoform

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In June 1995, the Columbia River Estuary Study Taskforce (CREST) acquired 295 true color aerial photographs (1:12,000) of Willapa Bay, Washington, from the State of...

  17. Willapa Bay, Washington Benthic Habitats 1995 Substrate

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In June 1995, the Columbia River Estuary Study Taskforce (CREST) acquired 295 true color aerial photographs (1:12,000) of Willapa Bay, Washington, from the State of...

  18. Wastewater Out Front in Bay Restoration

    Science.gov (United States)

    Clean Water Act programs administered by EPA and the delegated states have played a central role in the success of the wastewater sector in effectively meeting nutrient limits in the Chesapeake Bay “pollution diet” a decade early.

  19. Biscayne Bay Florida Bottlenose Dolphin Studies

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data sets include a compilation of small vessel based studies of bottlenose dolphins that reside within Biscayne Bay, Florida, adjacent estuaries and nearshore...

  20. South Bay Salt Ponds : Initial stewardship plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The California Department of Fish and Game and the U.S. Fish and Wildlife Service will operate and maintain the South Bay Salt Ponds under this Initial Stewardship...

  1. Back Bay National Wildlife Refuge: Master Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Back Bay National Wildlife Refuge, located in the city of Virginia Beach, Virginia, comprises 4,608 acres of barrier beach, fresh and brackish marsh, small...

  2. Historical methyl mercury in San Francisco Bay

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — San Francisco Bay, California is considered a mercury-impaired watershed. Elevated concentrations of mercury are found in water and sediment as well as fish and...

  3. Naive Bayes Image Classification: beyond Nearest Neighbors

    OpenAIRE

    Timofte, Radu; Tuytelaars, Tinne; Van Gool, Luc

    2012-01-01

    Timofte R., Tuytelaars T., Van Gool L., ''Naive bayes image classification: beyond nearest neighbors'', 11th Asian conference on computer vision - ACCV 2012, 13 pp., November 5-9, 2012, Daejeon, Korea.

  4. Saginaw Bay Restoration Assessment Degree Flowlines

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This represents the flowline network in Sagina Bay Restoration Assessment (SBRA). It is attributed with the number of disconnections between the reach and the...

  5. Willapa Bay, Washington Benthic Habitats 1995 Geodatabase

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In June 1995, the Columbia River Estuary Study Taskforce (CREST) acquired 295 true color aerial photographs (1:12,000) of Willapa Bay, Washington, from the State of...

  6. The surface heat budget of Hudson Bay

    National Research Council Canada - National Science Library

    Danielson, E.W

    1969-01-01

    ... which information the heat budget calculations are based. These data include surface air and sea temperatures, ice concentration, cloudiness, wind, atmospheric moisture, ice and water movement, and heat storage amounts within Hudson Bay waters...

  7. Differential productivity of Bristol Bay spawning grounds

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Bristol Bay escapement surveys covering a period of several years show that, irrespective of fluctuations in total numbers on a system, certain grounds display a...

  8. Improved oilfield GHG accounting using a global oilfield database

    Science.gov (United States)

    Roberts, S.; Brandt, A. R.; Masnadi, M.

    2016-12-01

    The definition of oil is shifting in considerable ways. Conventional oil resources are declining as oil sands, heavy oils, and others emerge. Technological advances mean that these unconventional hydrocarbons are now viable resources. Meanwhile, scientific evidence is mounting that climate change is occurring. The oil sector is responsible for 35% of global greenhouse gas (GHG) emissions, but the climate impacts of these new unconventional oils are not well understood. As such, the Oil Climate Index (OCI) project has been an international effort to evaluate the total life-cycle environmental GHG emissions of different oil fields globally. Over the course of the first and second phases of the project, 30 and 75 global oil fields have been investigated, respectively. The 75 fields account for about 25% of global oil production. For the third phase of the project, it is aimed to expand the OCI to contain closing to 100% of global oil production; leading to the analysis of 8000 fields. To accomplish this, a robust database system is required to handle and manipulate the data. Therefore, the integration of the data into the computer science language SQL (Structured Query Language) was performed. The implementation of SQL allows users to process the data more efficiently than would be possible by using the previously established program (Microsoft Excel). Next, a graphic user interface (gui) was implemented, in the computer science language of C#, in order to make the data interactive; enabling people to update the database without prior knowledge of SQL being necessary.

  9. Gradient Analysis and Classification of Carolina Bay Vegetation: A Framework for Bay Wetlands Conservation and Restoration

    Energy Technology Data Exchange (ETDEWEB)

    Diane De Steven,Ph.D.; Maureen Tone,PhD.

    1997-10-01

    This report address four project objectives: (1) Gradient model of Carolina bay vegetation on the SRS--The authors use ordination analyses to identify environmental and landscape factors that are correlated with vegetation composition. Significant factors can provide a framework for site-based conservation of existing diversity, and they may also be useful site predictors for potential vegetation in bay restorations. (2) Regional analysis of Carolina bay vegetation diversity--They expand the ordination analyses to assess the degree to which SRS bays encompass the range of vegetation diversity found in the regional landscape of South Carolina's western Upper Coastal Plain. Such comparisons can indicate floristic status relative to regional potentials and identify missing species or community elements that might be re-introduced or restored. (3) Classification of vegetation communities in Upper Coastal Plain bays--They use cluster analysis to identify plant community-types at the regional scale, and explore how this classification may be functional with respect to significant environmental and landscape factors. An environmentally-based classification at the whole-bay level can provide a system of templates for managing bays as individual units and for restoring bays to desired plant communities. (4) Qualitative model for bay vegetation dynamics--They analyze present-day vegetation in relation to historic land uses and disturbances. The distinctive history of SRS bays provides the possibility of assessing pathways of post-disturbance succession. They attempt to develop a coarse-scale model of vegetation shifts in response to changing site factors; such qualitative models can provide a basis for suggesting management interventions that may be needed to maintain desired vegetation in protected or restored bays.

  10. 77 FR 2972 - Thunder Bay Power Company, Thunder Bay Power, LLC, et al.

    Science.gov (United States)

    2012-01-20

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Thunder Bay Power Company, Thunder Bay Power, LLC, et al.; Notice of..., 2347-049, 2373-010 Midwest Hydro, LLC Midwest Hydraulic Company, Inc Project No. 10805-054 Midwest...

  11. Map showing thickness of young bay mud, southern San Francisco Bay, California

    Science.gov (United States)

    McDonald, Sandra D.; Nichols, Donald R.; Wright, Nancy A.; Atwater, Brian

    1978-01-01

    Soft water-saturated estuarine deposits less than 10,000 years old underlie the southern part of San Francisco bay and the present and former marshlands that border the bay. Known locally as bay mud or as young bay mud, these deposits, and the estuarine environment that produces them, are of major importance in making decision on land use and development in the San Francisco Bay area. Knowledge of the distribution, thickness, and physical properties of young bay mud is critical to the feasibility, design, and maintenance of structures built on it. Fore this reason, numerous attempts have been made in the past to map or describe these characteristics (Mitchell, 1963; Goldman, 1969; McDonald and Nichols, 1974). The accompanying map of bay-mud thickness significantly revises part of an earlier compilation by Kahle and Goldman (1969) and includes new data from approximately 2400 boreholes, most of which have been drilled during the past 15 years. It also incorporates information on historic margins of San Francisco Bay and its tidal marshes (Nichols and Wright, 1971). Although this map was compelled mostly from data gathered during foundation investigations and construction projects, it is mostly from data gathered during foundation investigations and construction projects, it is not a substitute for such studies. Rather, the map provides regional information for land-use planning, seismic zonation, and design of foundation investigations.

  12. BOOK REVIEW OF "CHESAPEAKE BAY BLUES: SCIENCE, POLITICS, AND THE STRUGGLE TO SAVE THE BAY"

    Science.gov (United States)

    This is a book review of "Chesapeake Bay Blues: Science, Politics, and the Struggle to Save the Bay". This book is very well written and provides an easily understandable description of the political challenges faced by those proposing new or more stringent environmental regulat...

  13. Influenza in Bristol Bay, 1919

    Directory of Open Access Journals (Sweden)

    Maria Gilson deValpine

    2015-03-01

    Full Text Available The 1918 influenza pandemic has been blamed for as many as 50 million deaths worldwide. Like all major disasters, the full story of the pandemic includes smaller, less noted episodes that have not attracted historical attention. The story of the 1919 wave of the influenza pandemic in Bristol Bay Alaska is one such lost episode. It is an important story because the most accessible accounts—the Congressional Record and the Coast Guard Report—are inconsistent with reports made by employees, health care workers, and volunteers at the site of the disaster. Salmon fishing industry supervisors and medical officers recorded their efforts to save the region’s Native Alaskans in private company reports. The federal Bureau of Education physician retained wireless transmission, reports, and letters of events. The Coast Guard summarized its work in its Annual Report of 1920. The independent Bureau of Fisheries report to the Department of Commerce reveals the Coast Guard report at striking odds with others and reconciles only one account. This article explores the historical oversight, and attempts to tell the story of the 1919 wave of the pandemic which devastated the Native Alaskan population in this very remote place.

  14. Bayes Syndrome and Imaging Techniques.

    Science.gov (United States)

    Betancor, Ivan Hernandez; Izquierdo-Gomez, Maria Manuela; Niebla, Javier Garcia; Laynez-Cerdeña, Ignacio; Garcia-Gonzalez, Martin Jesus; Barragan-Acea, Antonio; Iribarren-Sarriá, Jose Luis; Jimenez-Rivera, Juan Jose; Lacalzada-Almeida, Juan

    2017-07-13

    Interatrial block (IAB) is due to disruption in the Bachmann region (BR). According to whether interatrial electrical conduction is delayed or completely blocked through the BR, it can be classified as IAB of first, second or third degree. On the surface electrocardiogram, a P wave ≥ 120 ms (partial IAB) is observed or associated to the prolongation of the P wave with a biphasic (positive / negative) morphology in the inferior leads (advanced IAB). Bayes syndrome is defined as an advanced IAB associated with atrial arrhythmia, more specifically atrial fibrillation. The purpose of this review is to describe the latest evidence about an entity considered an anatomical and electrical substrate with its own name, which may be a predictor of supraventricular arrhythmia and cardioembolic cerebrovascular accidents, as well as the role of new imaging techniques, such as echocardiographic strain and cardiac magnetic resonance imaging, in characterizing atrial alterations associated with this syndrome and generally in the study of anatomy and atrial function. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  15. Development drilling paces oilfield activity

    Energy Technology Data Exchange (ETDEWEB)

    McNally, R.

    1978-01-01

    A graph represents the oil, gas, and dry development well completion trends during the past 12 yr in the U.S. Development drilling these days is setting a pace that has rig employment in the U.S. at a modern high, with gains at times exceeding activity during comparable periods a year earlier by more than 30%. Increased development drilling, of course, reflects economic incentives of increased prices for new oil and higher prices available on the intrastate gas market. It also reflects the confusion and apprehension caused by government activity (or lack of activity) during the past year, in the U.S. at least. For example, exploratory drilling has not kept pace with overall increases in well completions during the years following the 1973 Arab oil embargo. Since 1971, completion of development wells has increased by 61% compared with an overall completion increase of 53%. During the first 3 quarters of 1977, development drilling accounted for 78% of the 31,900 wells completed in the U.S. This was an improvement of 2 percentage points over the similar period in 1976. Development drilling footage exceeded 104,000,000 during the first 3 quarters of 1977, an 8% gain over the previous year. Overall footage was up 7%, to almost 146,000,000.

  16. Gulf of Mexico Integrated Science - Tampa Bay Study - Historical and Prehistorical Record of Tampa Bay Environments

    Science.gov (United States)

    Edgar, Terry

    2005-01-01

    To study how Tampa Bay, Florida, has changed over time, the prehistorical conditions and natural variations in the bay environment are being evaluated. These variations can be tracked by examining the sediments that have accumulated in and around the bay. The prehistorical record, which pre-dates settlers' arrival in the Tampa Bay area around 1850, provides a baseline with which to compare and evaluate the magnitude and effects of sea-level, climate, biological, geochemical, and man-made changes. These data also are valuable for planning and conducting projects aimed at restoring wetlands and other estuarine habitats to their original state. In addition, the data provide a basis for judging efforts to improve the health of the bay.

  17. Geology, geochronology, and paleogeography of the southern Sonoma volcanic field and adjacent areas, northern San Francisco Bay region, California

    Science.gov (United States)

    Wagner, David L.; Saucedo, George J.; Clahan, Kevin B.; Fleck, Robert J.; Langenheim, Victoria E.; McLaughlin, Robert J.; Sarna-Wojcicki, Andrei M.; Allen, James R.; Deino, Alan L.

    2011-01-01

    Recent geologic mapping in the northern San Francisco Bay region (California, USA) supported by radiometric dating and tephrochronologic correlations, provides insights into the framework geology, stratigraphy, tectonic evolution, and geologic history of this part of the San Andreas transform plate boundary. There are 25 new and existing radiometric dates that define three temporally distinct volcanic packages along the north margin of San Pablo Bay, i.e., the Burdell Mountain Volcanics (11.1 Ma), the Tolay Volcanics (ca. 10–8 Ma), and the Sonoma Volcanics (ca. 8–2.5 Ma). The Burdell Mountain and the Tolay Volcanics are allochthonous, having been displaced from the Quien Sabe Volcanics and the Berkeley Hills Volcanics, respectively. Two samples from a core of the Tolay Volcanics taken from the Murphy #1 well in the Petaluma oilfield yielded ages of 8.99 ± 0.06 and 9.13 ± 0.06 Ma, demonstrating that volcanic rocks exposed along Tolay Creek near Sears Point previously thought to be a separate unit, the Donnell Ranch volcanics, are part of the Tolay Volcanics. Other new dates reported herein show that volcanic rocks in the Meacham Hill area and extending southwest to the Burdell Mountain fault are also part of the Tolay Volcanics. In the Sonoma volcanic field, strongly bimodal volcanic sequences are intercalated with sediments. In the Mayacmas Mountains a belt of eruptive centers youngs to the north. The youngest of these volcanic centers at Sugarloaf Ridge, which lithologically, chemically, and temporally matches the Napa Valley eruptive center, was apparently displaced 30 km to the northwest by movement along the Carneros and West Napa faults. The older parts of the Sonoma Volcanics have been displaced at least 28 km along the Rodgers Creek fault since ca. 7 Ma. The Petaluma Formation also youngs to the north along the Rodgers Creek–Hayward fault and the Bennett Valley fault. The Petaluma basin formed as part of the Contra Costa basin in the Late Miocene and

  18. 76 FR 23193 - Traffic Separation Schemes: In the Approaches to Portland, ME; Boston, MA; Narragansett Bay, RI...

    Science.gov (United States)

    2011-04-26

    ... Portland, ME; Boston, MA; Narragansett Bay, RI and Buzzards Bay, MA; Chesapeake Bay, VA, and Cape Fear... Portland, ME; in the approaches to Boston, MA; in the approaches to Narragansett Bay, RI and Buzzards Bay... Portland, ME; Boston, MA; Narragansett Bay, RI and Buzzards Bay, MA; Chesapeake Bay, VA; and Cape Fear...

  19. Radium isotopes in the Ulsan Bay

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Seong [Department of Oceanography, Chungnam National University, Gung-dong 220, Yuseong, Daejeon 305-764 (Korea, Republic of)]. E-mail: leejs728@nfrda.re.kr; Kim, Kee Hyun [Department of Oceanography, Chungnam National University, Gung-dong 220, Yuseong, Daejeon 305-764 (Korea, Republic of); Moon, Duck Soo [Department of Oceanography, Chungnam National University, Gung-dong 220, Yuseong, Daejeon 305-764 (Korea, Republic of)

    2005-07-01

    In order to estimate the fluxes of Ra isotopes, we measured {sup 224}Ra, {sup 226}Ra, and {sup 228}Ra activities in the Ulsan Bay mixing zone. The convex upwards curvature of the plot of Ra isotope activities versus salinity for the mixing zone suggests that Ra isotopes are supplied from particles entering the mixing zone from both the river and bottom sediments. This addition increases the estuarine flux of {sup 226}Ra and {sup 228}Ra to the outer sea by factors of 15 and 95 over the flux attributable to Ra dissolved in the riverine water alone. In order to estimate the residence time of the water in Ulsan Bay, we applied a mass balance model to the distribution of {sup 224}Ra and {sup 226}Ra activities in the Ulsan Bay mixing zone with the inflow from the Taehwa River. The obtained residence times of the waters in the Ulsan Bay were estimated to be 6.8-11.4 d. The waters in the upper part of the estuary have long residence times whereas those in the lower part, in contact with the open sea, have shorter residence times. The mean residence time of the water in the Ulsan Bay was estimated to be 9.1 d.

  20. Fishery Management Program Progress Report: Back Bay National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Memorandum containing summary of fishery biologist's visit to Back Bay to remove carp from impoundments at Back Bay National Wildlife Refuge.

  1. Parameter Identification by Bayes Decision and Neural Networks

    DEFF Research Database (Denmark)

    Kulczycki, P.; Schiøler, Henrik

    1994-01-01

    The problem of parameter identification by Bayes point estimation using neural networks is investigated.......The problem of parameter identification by Bayes point estimation using neural networks is investigated....

  2. SF Bay Water Quality Improvement Fund: Projects and Accomplishments

    Science.gov (United States)

    San Francisco Bay Water Quality Improvement Fund (SFBWQIF) projects listed here are part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

  3. Benthic grab data from October 1999 in Apalachicola Bay, Florida

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Apalachicola Bay National Estuarine Research Reserve and the NOAA Office for Coastal Management worked together to map benthic habitats within Apalachicola Bay,...

  4. Sediment grab data from October 1999 in Apalachicola Bay, Florida

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Apalachicola Bay National Estuarine Research Reserve and the NOAA Office for Coastal Management worked together to map benthic habitats within Apalachicola Bay,...

  5. South Bay Salt Pond Restoration, Phase II at Ravenswood

    Science.gov (United States)

    Information about the South Bay Salt Pond Restoration Project: Phase II Construction at Ravenswood, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

  6. Phytoplankton and nutrients studies in Magu bay, Speke gulf, Lake ...

    African Journals Online (AJOL)

    chemical parameters were studied in Magu Bay, Lake Victoria, in May 2001. Investigations on the influence of Simiyu River on the biological and physical characteristics of the Bay were carried out. Surface and bottom currents flowed in the ...

  7. Biology and subsistence hunting of geese at Chagvan Bay

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Chagvan Bay and Nanvak Bay are known to be important staging and/or stopover areas for large numbers of Pacific Brant (Branta bernicola) and Emperor Geese (Chen...

  8. 1999 RoxAnn Data Points from Apalachicola Bay, Florida

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Apalachicola Bay National Estuarine Research Reserve and the NOAA Office for Coastal Management worked together to map benthic habitats within Apalachicola Bay,...

  9. Technical Support Documents Used to Develop the Chesapeake Bay TMDL

    Science.gov (United States)

    The Chesapeake Bay TMDL development was supported by several technical documents for water quality standards and allocation methodologies specific to the Chesapeake Bay. This page provides the technical support documents.

  10. Algae Reefs in Shark Bay, Western Australia, Australia

    Science.gov (United States)

    1990-01-01

    Numerous algae reefs are seen in Shark Bay, Western Australia, Australia (26.0S, 113.5E) especially in the southern portions of the bay. The south end is more saline because tidal flow in and out of the bay is restricted by sediment deposited at the north and central end of the bay opposite the mouth of the Wooramel River. This extremely arid region produces little sediment runoff so that the waters are very clear, saline and rich in algae.

  11. Mapping Oyster Reef Habitats in Mobile Bay

    Science.gov (United States)

    Bolte, Danielle

    2011-01-01

    Oyster reefs around the world are declining rapidly, and although they haven t received as much attention as coral reefs, they are just as important to their local ecosystems and economies. Oyster reefs provide habitats for many species of fish, invertebrates, and crustaceans, as well as the next generations of oysters. Oysters are also harvested from many of these reefs and are an important segment of many local economies, including that of Mobile Bay, where oysters rank in the top five commercial marine species both by landed weight and by dollar value. Although the remaining Mobile Bay oyster reefs are some of the least degraded in the world, projected climate change could have dramatic effects on the health of these important ecosystems. The viability of oyster reefs depends on water depth and temperature, appropriate pH and salinity levels, and the amount of dissolved oxygen in the water. Projected increases in sea level, changes in precipitation and runoff patterns, and changes in pH resulting from increases in the amount of carbon dioxide dissolved in the oceans could all affect the viability of oyster reefs in the future. Human activities such as dredging and unsustainable harvesting practices are also adversely impacting the oyster reefs. Fortunately, several projects are already under way to help rebuild or support existing or previously existing oyster reefs. The success of these projects will depend on the local effects of climate change on the current and potential habitats and man s ability to recognize and halt unsustainable harvesting practices. As the extent and health of the reefs changes, it will have impacts on the Mobile Bay ecosystem and economy, changing the resources available to the people who live there and to the rest of the country, since Mobile Bay is an important national source of seafood. This project identified potential climate change impacts on the oyster reefs of Mobile Bay, including the possible addition of newly viable

  12. Lost lake - restoration of a Carolina bay

    Energy Technology Data Exchange (ETDEWEB)

    Hanlin, H.G.; McLendon, J.P. [Univ. of South Carolina, Aiken, SC (United States). Dept. of Biology and Geology; Wike, L.D. [Univ. of South Carolina, Aiken, SC (United States). Dept. of Biology and Geology]|[Westinghouse Savannah River Co., Aiken, SC (United States). Savannah River Technology Center; Dietsch, B.M. [Univ. of South Carolina, Aiken, SC (United States). Dept. of Biology and Geology]|[Univ. of Georgia, Aiken, SC (United States)

    1994-09-01

    Carolina bays are shallow wetland depressions found only on the Atlantic Coastal Plain. Although these isolated interstream wetlands support many types of communities, they share the common features of having a sandy margin, a fluctuating water level, an elliptical shape, and a northwest to southeast orientation. Lost Lake, an 11.3 hectare Carolina bay, was ditched and drained for agricultural production before establishment of the Savannah River Site in 1950. Later it received overflow from a seepage basin containing a variety of chemicals, primarily solvents and some heavy metals. In 1990 a plan was developed for the restoration of Lost Lake, and restoration activities were complete by mid-1991. Lost Lake is the first known project designed for the restoration and recovery of a Carolina bay. The bay was divided into eight soil treatment zones, allowing four treatments in duplicate. Each of the eight zones was planted with eight species of native wetland plants. Recolonization of the bay by amphibians and reptiles is being evaluated by using drift fences with pitfall traps and coverboard arrays in each of the treatment zones. Additional drift fences in five upland habitats were also established. Hoop turtle traps, funnel minnow traps, and dip nets were utilized for aquatic sampling. The presence of 43 species common to the region has been documented at Lost Lake. More than one-third of these species show evidence of breeding populations being established. Three species found prior to the restoration activity and a number of species common to undisturbed Carolina bays were not encountered. Colonization by additional species is anticipated as the wetland undergoes further succession.

  13. 77 FR 14276 - Regulated Navigation Area; Little Bay Bridge Construction, Little Bay, Portsmouth, NH

    Science.gov (United States)

    2012-03-09

    ...The Coast Guard is establishing a regulated navigation area (RNA) on the navigable waters of Little Bay in the Piscataqua River under and surrounding the Little Bay and General Sullivan Bridges in order to facilitate construction of the Little Bay Bridge between Newington, NH and Dover, NH. This temporary interim rule is necessary to provide for the safety of life on the navigable waters during bridge construction operations that could pose an imminent hazard to vessels operating in the area. This rule implements certain safety measures, including speed restrictions and the temporary suspension of vessel traffic during construction operations.

  14. Holocene evolution of Apalachicola Bay, Florida

    Science.gov (United States)

    Osterman, Lisa E.; Twichell, David C.

    2011-01-01

    A program of geophysical mapping and vibracoring was conducted in 2007 to better understand the geologic evolution of Apalachicola Bay and its response to sea-level rise. A detailed geologic history could help better understand how this bay may respond to both short-term (for example, storm surge) and long-term sea-level rise. The results of this study were published (Osterman and others, 2009) as part of a special issue of Geo-Marine Letters that documents early results from the Northern Gulf of Mexico (NGOM) Ecosystem Change and Hazard Susceptibility Project.

  15. An Empirical Bayes Approach to Spatial Analysis

    Science.gov (United States)

    Morris, C. N.; Kostal, H.

    1983-01-01

    Multi-channel LANDSAT data are collected in several passes over agricultural areas during the growing season. How empirical Bayes modeling can be used to develop crop identification and discrimination techniques that account for spatial correlation in such data is considered. The approach models the unobservable parameters and the data separately, hoping to take advantage of the fact that the bulk of spatial correlation lies in the parameter process. The problem is then framed in terms of estimating posterior probabilities of crop types for each spatial area. Some empirical Bayes spatial estimation methods are used to estimate the logits of these probabilities.

  16. Chondrichthyan occurrence and abundance trends in False Bay ...

    African Journals Online (AJOL)

    Commercial fishing in False Bay, South Africa, began in the 1600s. Today chondrichthyans are regularly taken in fisheries throughout the bay. Using a combination of catch, survey and life history data, the occurrence and long-term changes in populations of chondrichthyans in False Bay are described. Analyses of time ...

  17. 33 CFR 117.323 - Outer Clam Bay

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Outer Clam Bay 117.323 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.323 Outer Clam Bay The drawspan of the Outer Clam Bay Boardwalk Drawbridge shall open on signal if at least 30 minutes advance notice is given. ...

  18. 33 CFR 162.150 - Maumee Bay and River, Ohio.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Maumee Bay and River, Ohio. 162... (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.150 Maumee Bay and River, Ohio. (a) In Maumee Bay (lakeward of Maumee River Lighted Buoy 49(L/L No. 770)), no vessel greater than...

  19. Naïve Bayes classification in R

    OpenAIRE

    Zhang, Zhongheng

    2016-01-01

    Naïve Bayes classification is a kind of simple probabilistic classification methods based on Bayes’ theorem with the assumption of independence between features. The model is trained on training dataset to make predictions by predict() function. This article introduces two functions naiveBayes() and train() for the performance of Naïve Bayes classification.

  20. Naive Bayes and Text Classification I - Introduction and Theory

    OpenAIRE

    Raschka, Sebastian

    2014-01-01

    Naive Bayes classifiers, a family of classifiers that are based on the popular Bayes' probability theorem, are known for creating simple yet well performing models, especially in the fields of document classification and disease prediction. In this article, we will look at the main concepts of naive Bayes classification in the context of document categorization.

  1. 33 CFR 100.124 - Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay, New York.

    Science.gov (United States)

    2010-07-01

    .... (a) Regulated area. All navigable waters of Great South Bay, NY within a 100 yard radius of each... the Fire Island Lighthouse Dock in approximate position 40°38′01″ N 073°13′07″ W, northerly through.... (1) No person or vessel may enter, transit, or remain within 100 yards of any swimmer or safety craft...

  2. Susceptibilities of Human Cytomegalovirus Clinical Isolates to BAY38-4766, BAY43-9695, and Ganciclovir

    Science.gov (United States)

    McSharry, James J.; McDonough, Ann; Olson, Betty; Hallenberger, Sabine; Reefschlaeger, Juergen; Bender, Wolfgang; Drusano, George L.

    2001-01-01

    BAY38-4766 and BAY43-9695 are nonnucleosidic compounds with activities against human cytomegalovirus (HCMV). Two phenotypic assays were used to determine the drug susceptibilities of 36 HCMV clinical isolates to the BAY compounds and ganciclovir. Using either assay, both BAY compounds at a concentration of approximately 1 μM inhibited the replication of all 36 HCMV clinical isolates, including 11 ganciclovir-resistant clinical isolates, by 50%. PMID:11557492

  3. Geology and geomorphology--Drakes Bay and Vicinity Bay Map Area, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the geologic and geomorphic map of the Drakes Bay and Vicinity map area, California. The polygon shapefile is included in...

  4. Pärnu Bay Golf Club = Pärnu Bay Golf Club / Arhitekt11

    Index Scriptorium Estoniae

    2016-01-01

    Pärnu Bay Golf Club, arhitektid Jürgen Lepper, Anto Savi, Margus Soonets, Janar Toomesso (Arhitekt11), sisearhitektid Liina Vaino, Kaari Metslang, Hannelore Kääramees (Arhitekt11). Kultuurkapitali Arhitektuuri sihtkapitali aastapreemia nominent 2016

  5. Gravity cores from San Pablo Bay and Carquinez Strait, San Francisco Bay, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data release contains information on gravity cores that were collected by the U.S. Geological Survey in the area of San Pablo Bay and Carquinez Strait,...

  6. San Francisco Bay Water Quality Improvement Fund Points, SF Bay CA, 2015, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — The San Francisco Bay Water Quality Improvement Fund is a competitive grant program that is helping implement TMDLs to improve water quality, protect wetlands, and...

  7. Contaminants in redhead ducks wintering in Baffin Bay and Redfish Bay, Texas

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A sample of 39 redhead ducks was collected from Redfish and Baffin Bays on the Texas Coast during the winter of 1988-1989 to obtain baseline information on...

  8. Florida Bay Science Program: a Synthesis of Research on Florida Bay

    OpenAIRE

    Hunt, John; Nuttle, William

    2007-01-01

    This report documents the progress made toward the objectives established in the Strategic Plan revised in 1997 for the agencies cooperating in the program. These objectives are expressed as five questions that organized the research on the Florida Bay ecosystem: Ecosystem History What was the Florida Bay ecosystem like 50, 100, and 150 years ago? Question 1—Physical Processes How and at what rates do storms, changing freshwater flows, sea level rise, and local evaporatio...

  9. Carolina bays of the Savannah River Plant

    Energy Technology Data Exchange (ETDEWEB)

    Schalles, J.F. (Creighton Univ., Omaha, NE (USA)); Sharitz, R.R.; Gibbons, J.W.; Leversee, G.J.; Knox, J.N. (Savannah River Ecology Lab., Aiken, SC (USA))

    1989-01-01

    Much of the research to date on the Carolina bays of the Savannah River Plant and elsewhere has focused on certain species or on environmental features. Different levels of detail exist for different groups of organisms and reflect the diverse interests of previous investigators. This report summarizes aspects of research to date and presents data from numerous studies. 70 refs., 14 figs., 12 tabs.

  10. Bathymetry (2011) for Coral Bay, St. John

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a LiDAR (Light Detection & Ranging) 0.3x0.3 meter resolution depth surface for Coral Bay, St. John in the U.S. Virgin Islands (USVI). The...

  11. Madreporaria from the Bay of Batavia

    NARCIS (Netherlands)

    Umbgrove, J.H.F.

    1939-01-01

    INTRODUCTION In the Bay of Batavia there are patch-reefs and cays in different stadia of development. Some are small reefs still rather deep below sea level, other reefs bear a small sand cay. On the larger coral sand islands vegetation has developed ; moreover shingle ramparts and a moat have come

  12. Bathymetry (2011) for Fish Bay, St. John

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a LiDAR (Light Detection & Ranging) 0.3x0.3 meter resolution depth surface for Fish Bay, St. John in the U.S. Virgin Islands (USVI). The...

  13. PEMANFATAN TEOREMA BAYES DALAM PENENTUAN PENYAKIT THT

    Directory of Open Access Journals (Sweden)

    Sri Winiarti

    2012-05-01

    Full Text Available Dalam konsep pelacakan dalam mencari solusi dengan pendekatan artificial inteligent, ada berbagai metode  yang dapat diterapkan untuk mengatasi masalah ketidakpastian saat proses pelacakan terjadi. Salah satunya adalah teorema bayes. Adanya ketidakpastian pada proses pelacakan dapat terjadi karena adanya perubahan pengetahuan yang ada di dalam sistem. Untuk itu diperlukan adanya suatu metode untuk mengatasi permasalahan tersebut. Dalam penelitian ini telah diterapkan suatu metode untuk mengatasi ketidakpastian dengan teorema Bayes pada kasus pelacakan untuk mendiagnosa penyakit pada THT (Telinga,Hidung dan Tenggorokan.  Subjek pada penelitian ini adalah proses pelacakan untuk menentukan penyakit THT dengan model penalaran forward chaining dan metode kepastiannya menggunakan teorema bayes dengan cara menghitung nilai probabilitas suatu penyakit dan membandingkan probabilitas setiap gejalanya. Model pengembangan perangkat lunak yang digunakan dalam penelitian ini adalah Waterfall. Metode Waterfall diawali dengan analisis data, perancangan sistem, pengkodean menggunakan Visual Basic 6.0, pengujian sistem dengan black box test dan alfa test. Dari penelitian yang dilakukan menghasilkan sebuah perangkat lunak yaitu  yang mampu menentukan penyakit pada THT dengan menerapkan metode bayes untuk mengatasi ketidakpastian. Hasil uji coba sistem menujukkan bahwa aplikasi ini layak dan dapat digunakan.

  14. Morphological features in the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, K.V.L.N.S.; Ramana, M.V.; Subrahmanyam, V.; Krishna, K.S.; Ramprasad, T.; Desa, M.

    the NW-SE trending long profiles spaced at 30 nautical miles aided to improve the bathymetry chart of the Bay of Bengal. The echograms show some important geo-morphological features of the seafloor. One such feature is the "Swatch of no ground" which...

  15. Chesapeake Bay Program Water Quality Database

    Science.gov (United States)

    The Chesapeake Information Management System (CIMS), designed in 1996, is an integrated, accessible information management system for the Chesapeake Bay Region. CIMS is an organized, distributed library of information and software tools designed to increase basin-wide public access to Chesapeake Bay information. The information delivered by CIMS includes technical and public information, educational material, environmental indicators, policy documents, and scientific data. Through the use of relational databases, web-based programming, and web-based GIS a large number of Internet resources have been established. These resources include multiple distributed on-line databases, on-demand graphing and mapping of environmental data, and geographic searching tools for environmental information. Baseline monitoring data, summarized data and environmental indicators that document ecosystem status and trends, confirm linkages between water quality, habitat quality and abundance, and the distribution and integrity of biological populations are also available. One of the major features of the CIMS network is the Chesapeake Bay Program's Data Hub, providing users access to a suite of long- term water quality and living resources databases. Chesapeake Bay mainstem and tidal tributary water quality, benthic macroinvertebrates, toxics, plankton, and fluorescence data can be obtained for a network of over 800 monitoring stations.

  16. Saginaw Bay, MI LiDAR

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME:(NRCS) Saginaw Bay, MI LiDAR LiDAR Data Acquisition and Processing Production Task USGS Contract No. G10PC00057 Task Order No. G11PD01254 Woolpert Order...

  17. (IMPS) at Makoba Bay, Zanzibar, Tanzania

    African Journals Online (AJOL)

    Daisy Ouya

    sedimentation pond, in that order. Water from the reservoir flows through the pond system by gravity. In the late 18th Century a powerful cyclone hit. Unguja Island. As a result, the estuarine sediments in the Bay have remained blackish in colour, sticky,.

  18. Summary report on Bristol Bay murre mortality

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — At least 86,000 common murres died in Bristol Bay, Alaska during a brief period in late April of this year. Evidence suggests that it was a catastrophic event of...

  19. Projected Commercial Maritime Activity in the Western Arctic

    Science.gov (United States)

    1977-10-01

    Unimak Island 29 10 Minimum Ship Requirements by Arctic Ship Class for Various 35 Ice Control Zones 11 Components of the PVIS Subsystems 49 LIST OF...1978 to 2000 6 Projected Oil Production Regions and When Major Production 21 VBegins 7 March Ice I-formation for Prudhoe Bay to Unimak Island Ship 30...Route September Ice Informetion for Prudhoe Bay to Unimak Island 31 Ship Route 9 Ice Class Designation 36 10 Requirements for Ice Class and Tonnage Size

  20. Comparison of Ecological Impacts of Postulated Oil Spills at Selected Alaskan Locations. Volume 1. Introduction, Summary, Methodology, Evaluation and Appendices

    Science.gov (United States)

    1975-06-01

    Graham Kami’s hak Bay Unimak Pass Port Möller 1 Kvichak Bay St. Matthew Island Nome Cape Blossom Offshore Prudhoe Onshore Prudhoe Umiat...Crossing, the cases found to have the greatest impact involved Port Graham, Valdez Narrows, Drift River, and Unimak Pass. The highest impact score...Valdez Narrows, Port Graham, Unimak Pass, Yukon River Crossing, and Drift River dominated the list of high impact scores in those cases where

  1. An empirical Bayes approach for the Poisson life distribution.

    Science.gov (United States)

    Canavos, G. C.

    1973-01-01

    A smooth empirical Bayes estimator is derived for the intensity parameter (hazard rate) in the Poisson distribution as used in life testing. The reliability function is also estimated either by using the empirical Bayes estimate of the parameter, or by obtaining the expectation of the reliability function. The behavior of the empirical Bayes procedure is studied through Monte Carlo simulation in which estimates of mean-squared errors of the empirical Bayes estimators are compared with those of conventional estimators such as minimum variance unbiased or maximum likelihood. Results indicate a significant reduction in mean-squared error of the empirical Bayes estimators over the conventional variety.

  2. Chesapeake Bay Watershed - Protecting the Chesapeake Bay and its rivers through science, restoration, and partnership

    Science.gov (United States)

    ,

    2012-01-01

    The Chesapeake Bay, the Nation's largest estuary, has been degraded due to the impact of human-population increase, which has doubled since 1950, resulting in degraded water quality, loss of habitat, and declines in populations of biological communities. Since the mid-1980s, the Chesapeake Bay Program (CBP), a multi-agency partnership which includes the Department of Interior (DOI), has worked to restore the Bay ecosystem. The U.S. Geological Survey (USGS) has the critical role of providing unbiased scientific information that is utilized to document and understand ecosystem change to help assess the effectiveness of restoration strategies in the Bay and its watershed. The USGS revised its Chesapeake Bay science plan for 2006-2011 to address the collective needs of the CBP, DOI, and USGS with a mission to provide integrated science for improved understanding and management of the Bay ecosystem. The USGS science themes for this mission are: Causes and consequences of land-use change; Impact of climate change and associated hazards; Factors affecting water quality and quantity; Ability of habitat to support fish and bird populations; and Synthesis and forecasting to improve ecosystem assessment, conservation, and restoration.

  3. Responses of upland herpetofauna to the restoration of Carolina Bays and thinning of forested Bay Margins.

    Energy Technology Data Exchange (ETDEWEB)

    Ledvina, Joseph A.

    2008-05-01

    Research on the effects of wetland restoration on reptiles and amphibians is becoming more common, but almost all of these studies have observed the colonization of recently disturbed habitats that were completely dry at the time of restoration. In a similar manner, investigations herpetofaunal responses to forest management have focused on clearcuts, and less intensive stand manipulations are not as well studied. To evaluate community and population responses of reptiles and amphibians to hydrology restoration and canopy removal in the interior of previously degraded Carolina bays, I monitored herpetofauna in the uplands adjacent to six historically degraded Carolina bays at the Savannah River Site (SRS) in South Carolina for four years after restoration. To evaluate the effects of forest thinning on upland herpetofauna, forests were thinned in the margins of three of these bays. I used repeated measures ANOVA to compare species richness and diversity and the abundance of selected species and guilds between these bays and with those at three reference bays that were not historically drained and three control bays that remained degraded. I also used Non-metric Multidimensional Scaling (NMDS) to look for community-level patterns based treatments.

  4. POTENTIAL HAZARDS OF SEDIMENT IN KENDARI BAY, SOUTHEAST SULAWESI

    Directory of Open Access Journals (Sweden)

    Nur Adi Kristanto

    2017-07-01

    Full Text Available Kendari bay is located in front of Kendari city. There are two harbors in the inner part of bay which very important to support economic activities such as shipping and passenger transportation. The result of coastal characteristic mapping and physical oceanography survey show various coastal morphology, vegetation, weathering processes, sedimentation, currents, and water depth and sea floor morphology. Kendari bay is an enclosed bay; the area is wide in the inner part and narrow in mouth of bay (outlet, the morphology look like a bottle’s neck. Numerous mouth rivers are concentrate around the bay. The rivers load material from land since erosion on land is intensive enough. There is indication that sediment supplies from land trough river mouth not equivalent with outlet capacity. Sediment load is trapped in the inner bay caused the outlet morphology. So high sediment rate play an important role in the process of shallow of water depth in Kendari bay. This condition make the Kendari bay is a prone area of sediment hazard due to height rate of sedimentary process. Therefore, to anticipate the hazards, precaution should be taken related to the Kendari bay as the center of activities in southeast of Sulawesi. The further survey is needed such as marine geotechnique and on land environmental to collect data, which can be used as database for development planning. Key words: Potential hazard, sediment, Kendari Bay Teluk

  5. Biological baseline data Youngs Bay, Oregon, 1974

    Energy Technology Data Exchange (ETDEWEB)

    McMechan, K.J. (ed.); Higley, D.L.; Holton, R.L.

    1975-04-01

    This report presents biological baseline information gathered during the research project, Physical, Chemical and Biological Studies on Youngs Bay.'' Youngs Bay is a shallow embayment located on the south shore of the Columbia River, near Astoria, Oregon. Research on Youngs Bay was motivated by the proposed construction by Alumax Pacific Aluminum Corporation of an aluminum reduction plant at Warrenton, Oregon. The research was designed to provide biological baseline information on Youngs Bay in anticipation of potential harmful effects from plant effluents. The information collected concerns the kinds of animals found in the Youngs Bay area, and their distribution and seasonal patterns of abundance. In addition, information was collected on the feeding habits of selected fish species, and on the life history and behavioral characteristics of the most abundant benthic amphipod, Corophium salmonis. Sampling was conducted at approximately three-week intervals, using commonly accepted methods of animal collection. Relatively few stations were sampled for fish, because of the need to standardize conditions of capture. Data on fish capture are reported in terms of catch-per-unit effort by a particular sampling gear at a specific station. Methods used in sampling invertebrates were generally more quantitative, and allowed sampling at a greater variety of places, as well as a valid basis for the computation of densities. Checklists of invertebrate species and fish species were developed from these samples, and are referred to throughout the report. The invertebrate checklist is more specific taxonomically than are tables reporting invertebrate densities. This is because the methods employed in identification were more precise than those used in counts. 9 refs., 27 figs., 25 tabs.

  6. Hierarchical Naive Bayes for genetic association studies.

    Science.gov (United States)

    Malovini, Alberto; Barbarini, Nicola; Bellazzi, Riccardo; de Michelis, Francesca

    2012-01-01

    Genome Wide Association Studies represent powerful approaches that aim at disentangling the genetic and molecular mechanisms underlying complex traits. The usual "one-SNP-at-the-time" testing strategy cannot capture the multi-factorial nature of this kind of disorders. We propose a Hierarchical Naïve Bayes classification model for taking into account associations in SNPs data characterized by Linkage Disequilibrium. Validation shows that our model reaches classification performances superior to those obtained by the standard Naïve Bayes classifier for simulated and real datasets. In the Hierarchical Naïve Bayes implemented, the SNPs mapping to the same region of Linkage Disequilibrium are considered as "details" or "replicates" of the locus, each contributing to the overall effect of the region on the phenotype. A latent variable for each block, which models the "population" of correlated SNPs, can be then used to summarize the available information. The classification is thus performed relying on the latent variables conditional probability distributions and on the SNPs data available. The developed methodology has been tested on simulated datasets, each composed by 300 cases, 300 controls and a variable number of SNPs. Our approach has been also applied to two real datasets on the genetic bases of Type 1 Diabetes and Type 2 Diabetes generated by the Wellcome Trust Case Control Consortium. The approach proposed in this paper, called Hierarchical Naïve Bayes, allows dealing with classification of examples for which genetic information of structurally correlated SNPs are available. It improves the Naïve Bayes performances by properly handling the within-loci variability.

  7. New insights into the distribution and evolution of the Cenozoic Tan-Lu Fault Zone in the Liaohe sub-basin of the Bohai Bay Basin, eastern China

    Science.gov (United States)

    Huang, Lei; Liu, Chi-yang; Xu, Chang-gui; Wu, Kui; Wang, Guang-yuan; Jia, Nan

    2018-01-01

    As the largest strike-slip fault system in eastern China, the northeast-trending Tan-Lu Fault Zone (TLFZ) is a significant tectonic element contributing to the Mesozoic-Cenozoic regional geologic evolution of eastern Asia, as well as to the formation of ore deposits and oilfields. Because of the paucity of data, its distribution and evolutionary history in the offshore Liaohe sub-basin of the northern Bohai Bay Basin (BBB) are still poorly understood. Investigations of the strike-slip fault system in the western portion of the offshore Liaohe sub-basin via new seismic data provide us with new insights into the characteristics of the Cenozoic TLFZ. Results of this study show that Cenozoic dextral strike-slip faults occurred near the center of the Liaoxi graben in the offshore Liaohe sub-basin; these strike-slip faults connect with their counterparts to the north, the western part of the onshore Liaohe sub-basin, and have similar characteristics to those in other areas of the BBB in terms of kinematics, evolutionary history, and distribution; consequently, these faults are considered as the western branch of the TLFZ. All strike-slip faults within the Liaoxi graben merge at depth with a central subvertical basement fault induced by the reactivation of a pre-existing strike-slip basement fault, the pre-Cenozoic TLFZ. Data suggest that the TLFZ across the whole Liaohe sub-basin comprises two branches and that the Cenozoic distribution of this system was inherited from the pre-Cenozoic TLFZ. This characteristic distribution might be possessed by the whole TLFZ, thus the new understandings about the distribution and evolutionary model of the TLFZ in this study can be inferred in many research fields along the whole fault zone, such as regional geology, ore deposits, petroleum exploration and earthquake hazard.

  8. Urban Noise Modelling in Boka Kotorska Bay

    Directory of Open Access Journals (Sweden)

    Aleksandar Nikolić

    2014-04-01

    Full Text Available Traffic is the most significant noise source in urban areas. The village of Kamenari in Boka Kotorska Bay is a site where, in a relatively small area, road traffic and sea (ferry traffic take place at the same time. Due to the specificity of the location, i.e. very rare synergy of sound effects of road and sea traffic in the urban area, as well as the expressed need for assessment of noise level in a simple and quick way, a research was conducted, using empirical methods and statistical analysis methods, which led to the creation of acoustic model for the assessment of equivalent noise level (Leq. The developed model for noise assessment in the Village of Kamenari in Boka Kotorska Bay quite realistically provides data on possible noise levels at the observed site, with very little deviations in relation to empirically obtained values.

  9. Pockmarks in Passamaquoddy Bay, New Brunswick, Canada

    Science.gov (United States)

    Brothers, Laura; Legere, Christine; Hughes Clark, J.E.; Kelley, J.T.; Barnhardt, Walter; Andrews, Brian; Belknap, D.F.

    2016-01-01

    Pockmarks are seafloor depressions associated with fluid escape (Judd & Hovland 2007). They proliferate in the muddy seafloors of coastal Gulf of Maine and Bay of Fundy, where they are associated with shallow natural gas likely of biogenic origin (Ussler et al. 2003; Rogers et al. 2006; Wildish et al. 2008). In North America, shallow-water pockmark fields are not reported south of Long Island Sound, despite the abundance of gassy, muddy estuaries. The absence of pockmarks south of the limit of North American glaciation suggests that local and regional heterogeneities, possibly related to glacial or sea-level history or bedrock geology, influence pockmark field distribution. In shallow-water embayments, such as Passamaquoddy Bay, New Brunswick, pockmarks can be large (>200 m diameter) and number in the thousands.

  10. Thatcher Bay, Washington, Nearshore Restoration Assessment

    Science.gov (United States)

    Breems, Joel; Wyllie-Echeverria, Sandy; Grossman, Eric E.; Elliott, Joel

    2009-01-01

    The San Juan Archipelago, located at the confluence of the Puget Sound, the Straits of Juan de Fuca in Washington State, and the Straits of Georgia, British Columbia, Canada, provides essential nearshore habitat for diverse salmonid, forage fish, and bird populations. With 408 miles of coastline, the San Juan Islands provide a significant portion of the available nearshore habitat for the greater Puget Sound and are an essential part of the regional efforts to restore Puget Sound (Puget Sound Shared Strategy 2005). The nearshore areas of the San Juan Islands provide a critical link between the terrestrial and marine environments. For this reason the focus on restoration and conservation of nearshore habitat in the San Juan Islands is of paramount importance. Wood-waste was a common by-product of historical lumber-milling operations. To date, relatively little attention has been given to the impact of historical lumber-milling operations in the San Juan Archipelago. Thatcher Bay, on Blakely Island, located near the east edge of the archipelago, is presented here as a case study on the restoration potential for a wood-waste contaminated nearshore area. Case study components include (1) a brief discussion of the history of milling operations. (2) an estimate of the location and amount of the current distribution of wood-waste at the site, (3) a preliminary examination of the impacts of wood-waste on benthic flora and fauna at the site, and (4) the presentation of several restoration alternatives for the site. The history of milling activity in Thatcher Bay began in 1879 with the construction of a mill in the southeastern part of the bay. Milling activity continued for more than 60 years, until the mill closed in 1942. Currently, the primary evidence of the historical milling operations is the presence of approximately 5,000 yd3 of wood-waste contaminated sediments. The distribution and thickness of residual wood-waste at the site was determined by using sediment

  11. MSL-1 reservicing in OPF Bay 1

    Science.gov (United States)

    2000-01-01

    KSC payloads processing employees work to reservice the Microgravity Science Laboratory-1 (MSL-1) Spacelab module in the Space Shuttle Orbiter Columbia's payload bay for the STS-94 mission in Orbiter Processing Facility 1. That mission is now scheduled to lift off in early July. This was the first time that this type of payload was reserviced without removing it from the payload bay. This new procedure pioneers processing efforts for quick relaunch turnaround times for future payloads. The Spacelab module was scheduled to fly again with the full complement of STS-83 experiments after that mission was cut short due to a faulty fuel cell. During the scheduled 16-day STS-94 mission, the experiments will be used to test some of the hardware, facilities and procedures that are planned for use on the International Space Station while the flight crew conducts combustion, protein crystal growth and materials processing experiments.

  12. The Bay of Pigs: Revisiting Two Museums

    Directory of Open Access Journals (Sweden)

    Peter Read

    2007-08-01

    Full Text Available The Museum of Playa Giron (the Bay of Pigs in the region of Cienega De Zapata, Cuba, celebrates the repulse of Brigade 2506 as the first reverse of US imperialism on the American continents. The equivalent Brigade 2506 Museum in Miami, dedicated to and maintained by the members of Brigade 2506, celebrates defeat at the Bay of Pigs as moral victory for the Cuban exiles. The forces were indeed implacable foes. Yet between the museums can be detected some curious similarities. Both present the common theme of the confrontation between forces of good and evil. Both celebrate the philosophy that dying for one’s country is the greatest good a citizen may achieve. Both museums fly the common Cuban flag. Both museums identify a common enemy: the United States of America. This article, by comparing the displays in the two museums, analyses some cultural elements of what, despite decades of separation, in some ways remains a common Cuban culture.

  13. New and Improved Results from Daya Bay

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    Despite the great progress achieved in the last decades, neutrinos remain among the least understood fundamental particles to have been experimentally observed. The Daya Bay Reactor Neutrino Experiment consists of eight identically designed detectors placed underground at different baselines from three groups of nuclear reactors in China, a configuration that is ideally suited for studying the properties of these elusive particles. In this talk I will review the improved results released last summer by the Daya Bay collaboration. These results include (i) a precision measurement of the θ13 mixing angle and the effective mass splitting in the electron antineutrino disappearance channel with a dataset comprising more than 2.5 million antineutrino interactions, (ii) a high-statistics measurement of the absolute flux and spectrum of reactor-produced electron antineutrinos, and (iii) a search for light sterile neutrino mixing performed with more than three times the statistics of the previous result. I w...

  14. Stratification on the Skagit Bay Tidal Flats

    Science.gov (United States)

    2012-09-01

    shore Skagit Bay a Camano Island -1 0 1 -2-1012 0.5 -0.5 1 -1 C ro ss -s ho re (k m ) Alongshore (km) 0 b 1 0 -1 Bed level (m ) 18 2.2 Modeled...shadowed by Camano Island, which forms the southern border of the tidal flats (Fig. 2-3c). Saline water has propagated onshore and a roughly

  15. Bechevin Bay, Alaska, Inlet Stability Study.

    Science.gov (United States)

    1985-05-01

    Krenitzin. Bechevin Inlet, Bechevin Bay, and Isanotski Strait form an inlet system which * separates Unimak Island from the Alaska Peninsula. This...from the North Pacific must travel around Unimak Island through Unimak Pass. This route is 100-150 miles longer than the route through the Bechevin...period was semidiurnal, while the tidal flow at Unimak Pass (not too far southwest from the study area) was, interestingly, diurnal. Second, the phase

  16. IRST infrared background analysis of bay environments

    CSIR Research Space (South Africa)

    Schwering, PBW

    2008-04-01

    Full Text Available environment. Some sensor management approaches for application in IRST systems is discussed. Keywords: Infrared backgrounds, coastal bay analysis, small surface target contrasts, IRST application. 1. INTRODUCTION More and more, coastal... in environments with highly cluttered backgrounds as well as rapidly varying atmospheric conditions. Threat contrasts may be low and varying in littoral environments, and the amount of background clutter can be severe. Electro-optical sensors, used for detection...

  17. Distribution of Seagrasses in Inner Ambon Bay

    OpenAIRE

    Irawan, Andri; Nganro, Noorsalam R

    2016-01-01

    Excessive sedimentation in Inner Ambon Bay (IAB) is alleged to cause the degradation of seagrass ve-getation in the area. To get a clearer picture about the matter, we conducted a field study in October 2010 - January 2011 to describe the distribution and density of seagrass at several locations in IAB with different conditions of sedimentation levels. Data were collected using transects perpendicular to the coastline along the seagrass vegetation. The results showed that there were six speci...

  18. Experimental enhancement of pickleweed, Suisun Bay, California

    Science.gov (United States)

    Miles, A. Keith; Van Vuren, Dirk H.; Tsao, Danika C.; Yee, Julie L.

    2015-01-01

    As mitigation for habitat impacted by the expansion of a pier on Suisun Bay, California, two vehicle parking lots (0.36 ha and 0.13 ha) were restored by being excavated, graded, and contoured using dredged sediments to the topography or elevation of nearby wetlands. We asked if pickleweed (Sarcocornia pacifica L, [Amaranthaceae]) colonization could be enhanced by experimental manipulation on these new wetlands. Pickleweed dominates ecologically important communities at adjacent San Francisco Bay, but is not typically dominant at Suisun Bay probably because of widely fluctuating water salinity and is outcompeted by other brackish water plants. Experimental treatments (1.0-m2 plots) included mulching with pickleweed cuttings in either the fall or the spring, tilling in the fall, or applying organic enrichments in the fall. Control plots received no treatment. Pickleweed colonization was most enhanced at treatment plots that were mulched with pickleweed in the fall. Since exotic vegetation can colonize bare sites within the early phases of restoration and reduce habitat quality, we concluded that mulching was most effective in the fall by reducing invasive plant cover while facilitating native plant colonization.

  19. An overview of San Francisco Bay PORTS

    Science.gov (United States)

    Cheng, Ralph T.; McKinnie, David; English, Chad; Smith, Richard E.

    1998-01-01

    The Physical Oceanographic Real-Time System (PORTS) provides observations of tides, tidal currents, and meteorological conditions in real-time. The San Francisco Bay PORTS (SFPORTS) is a decision support system to facilitate safe and efficient maritime commerce. In addition to real-time observations, SFPORTS includes a nowcast numerical model forming a San Francisco Bay marine nowcast system. SFPORTS data and nowcast numerical model results are made available to users through the World Wide Web (WWW). A brief overview of SFPORTS is presented, from the data flow originated at instrument sensors to final results delivered to end users on the WWW. A user-friendly interface for SFPORTS has been designed and implemented. Appropriate field data analysis, nowcast procedures, design and generation of graphics for WWW display of field data and nowcast results are presented and discussed. Furthermore, SFPORTS is designed to support hazardous materials spill prevention and response, and to serve as resources to scientists studying the health of San Francisco Bay ecosystem. The success (or failure) of the SFPORTS to serve the intended user community is determined by the effectiveness of the user interface.

  20. Operational modal identification using variational Bayes

    Science.gov (United States)

    Li, Binbin; Der Kiureghian, Armen

    2017-05-01

    Operational modal analysis is the primary tool for modal parameter identification in civil engineering. Bayesian statistics offers an ideal framework for analyzing uncertainties associated with the identified modal parameters. However, the exact Bayesian formulation is usually intractable due to the high computational demand in obtaining the posterior distributions of modal parameters. In this paper, the variational Bayes method is employed to provide an approximate solution. Unlike the Laplace approximation and Monte Carlo sampling, the variational Bayes approach provides a gradient-free algorithm to analytically approximate the posterior distributions. Working with the state-space representation of a dynamical system, the variational Bayes approach for identification of modal parameters is derived by ignoring statistical correlation between latent variables and the model parameters. In this approach, the joint distribution of the state-transition and observation matrices as well as the joint distribution of the process noise and measurement error are firstly calculated analytically using conjugate priors. The distribution of modal parameters is extracted from these obtained joint distributions using a first-order Taylor series expansion. A robust implementation of the method is discussed by using square-root filtering and Cholesky decomposition. The proposed approach is illustrated by its application to an example mass-spring system and the One Rincon Hill Tower in San Francisco.

  1. Tidal power from the Bay of Fundy

    Energy Technology Data Exchange (ETDEWEB)

    van Walsum, W.

    1998-10-01

    The potential for tidal power development in New Brunswick`s Bay of Fundy was discussed. Alternative methods of tidal plant operation, suitable for the site conditions of the head of the Bay (where there are two continuous basins), were described. Tidal power is strongly influenced by site conditions. A simple mathematical model has shown that for the location at the head of the Bay, a linked-basins plant could produce 5 per cent more energy with only 53 per cent of the power generating machinery that would be required for a conventional paired basins scheme. The challenge is to find an economical, environmentally friendly way of extracting power and energy from the tides. An early study series from 1966 to 1988 has shown that tidal power can be economical, yet nothing has materialized beyond an 18 MW pilot plant at Annapolis because of environmental concerns. In 1977, this single basin tidal power plant was found to increase the tidal range at Boston by 30 cm. It was suggested that a `tidal fence` may be an ecologically acceptable solution to this problem. Attention was drawn to the need to draft a master plan for the development of Fundy`s tidal power potential, making sure that early development does not jeopardize optimum development of the total resource. 8 refs., 6 figs.

  2. Organic Matter Remineralization Predominates Phosphorus Cycling in the Mid-Bay Sediments in the Chesapeake Bay

    Energy Technology Data Exchange (ETDEWEB)

    Sunendra, Joshi R.; Kukkadapu, Ravi K.; Burdige, David J.; Bowden, Mark E.; Sparks, Donald L.; Jaisi, Deb P.

    2015-05-19

    The Chesapeake Bay, the largest and most productive estuary in the US, suffers from varying degrees of water quality issues fueled by both point and non–point source nutrient sources. Restoration of the bay is complicated by the multitude of nutrient sources, their variable inputs and hydrological conditions, and complex interacting factors including climate forcing. These complexities not only restrict formulation of effective restoration plans but also open up debates on accountability issues with nutrient loading. A detailed understanding of sediment phosphorus (P) dynamics enables one to identify the exchange of dissolved constituents across the sediment- water interface and aid to better constrain mechanisms and processes controlling the coupling between the sediments and the overlying waters. Here we used phosphate oxygen isotope ratios (δ18Op) in concert with sediment chemistry, XRD, and Mössbauer spectroscopy on the sediment retrieved from an organic rich, sulfidic site in the meso-haline portion of the mid-bay to identify sources and pathway of sedimentary P cycling and to infer potential feedback effect on bottom water hypoxia and surface water eutrophication. Isotope data indicate that the regeneration of inorganic P from organic matter degradation (remineralization) is the predominant, if not sole, pathway for authigenic P precipitation in the mid-bay sediments. We interpret that the excess inorganic P generated by remineralization should have overwhelmed any bottom-water and/or pore-water P derived from other sources or biogeochemical processes and exceeded saturation with respect to authigenic P precipitation. It is the first research that identifies the predominance of remineralization pathway against remobilization (coupled Fe-P cycling) pathway in the Chesapeake Bay. Therefore, these results are expected to have significant implications for the current understanding of P cycling and benthic-pelagic coupling in the bay, particularly on the

  3. Grand Bay-Banks Lake Stewardship Partnership - Phase 2

    Science.gov (United States)

    2006-11-01

    soils that are typically found beneath the wetlands. The Carolina bays are generally oval- shaped depressions and vary in size from one to several...layer of quartz sand, overlain by argillaceous, slightly phosphatic, dolomitic limestone. Small blue clasts of clay are common throughout the...McConnell and Hacke (1993) speculated that the circular shaped wetland areas called bays in the northern part of their study area (Grand Bay and Banks Lake

  4. Regional Sediment Management (RSM) Strategy for Mobile Bay, Alabama

    Science.gov (United States)

    2015-04-01

    used to model and evaluate the behavior of sediment placed within Mobile Bay. SEDIMENT TRANSPORT WITHIN MOBILE BAY: A sediment budget for Mobile...benthic invertebrates in the pit basin while not adversely impacting the pit with regards to fish utilization or recreational fishing. 2) A second...were seasonally occupied by fishery resource assemblages typical of greater Mobile Bay. Species composition included several taxa that exemplify

  5. Variational Assimilation of Glider Data in Monterey Bay

    Science.gov (United States)

    2011-01-01

    gliders and ten Slocum gliders were deployed in the Monterey Bay region, collecting temperature and salinity profiles (Ramp et al., 2008). Since the... Glider Data in the Monterey Bay 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 0601153N 6. AUTHOR(S) Chudong Pan, Max...observed by gliders in the Monterey Bay in August 2003 are assimilated into NCOM model in the framework of a 3dVar scheme with a hybrid background error

  6. The orbiter Discovery rolls from OPF bay 1 to bay 3

    Science.gov (United States)

    2000-01-01

    KSC employees chaperone the transfer of the orbiter Discovery from Orbiter Processing Facility (OPF) bay 1 to OPF bay 3 where ongoing payload and ground processing assessments will be completed. Managers will then determine when to roll the orbiter to the Vehicle Assembly Building for stacking with the external tank and solid rocket boosters, and when to roll out to Launch Pad 39A. Discovery is scheduled to launch Oct. 5 at 9:30 p.m. EDT on mission STS-92, which will be the 100th flight in the Shuttle program.

  7. Index for Assessing Water Trophic Status in Semi-Enclosed Cuban Bays. Case Study: Cienfuegos Bay

    CERN Document Server

    Seisdedo, Mabel; Arencibia, Gustavo

    2013-01-01

    This paper aims at contributing to the coastal environmental management by developing a new trophic status index of the water (TSIW). The index is tailored to semi-enclosed bays with estuarine characteristic like the Cienfuegos bay in Cuba. We also propose pressure indicators related to exporting and assimilation capacities as a tool to assess the vulnerability of the system to eutrophication. The TSIW is based on response indicators to eutrophication processes showing correspondence with the predefined pressure indicators and previous reports on water quality. Thus, the proposed trophic status index is a reliable scientific tool to measure the current stage of the water quality and to establish a baseline for further studies.

  8. Delineation of marsh types from Corpus Christi Bay, Texas, to Perdido Bay, Alabama, in 2010

    Science.gov (United States)

    Enwright, Nicholas M.; Hartley, Stephen B.; Couvillion, Brady R.; Michael G. Brasher,; Jenneke M. Visser,; Michael K. Mitchell,; Bart M. Ballard,; Mark W. Parr,; Barry C. Wilson,

    2015-07-23

    Coastal zone managers and researchers often require detailed information regarding emergent marsh vegetation types (that is, fresh, intermediate, brackish, and saline) for modeling habitat capacities and needs of marsh dependent taxa (such as waterfowl and alligator). Detailed information on the extent and distribution of emergent marsh vegetation types throughout the northern Gulf of Mexico coast has been historically unavailable. In response, the U.S. Geological Survey, in collaboration with the Gulf Coast Joint Venture, the University of Louisiana at Lafayette, Ducks Unlimited, Inc., and the Texas A&M University-Kingsville, produced a classification of emergent marsh vegetation types from Corpus Christi Bay, Texas, to Perdido Bay, Alabama.

  9. Control of hardwood regeneration in restored carolina bay depression wetlands.

    Energy Technology Data Exchange (ETDEWEB)

    Moser, Lee, J.; Barton, Christopher, D.; Blake, John, I.

    2012-06-01

    Carolina bays are depression wetlands located in the coastal plain region of the eastern United States. Disturbance of this wetland type has been widespread, and many sites contain one or more drainage ditches. Restoration of bays is of interest because they are important habitats for rare flora and fauna. Previous bay restoration projects have identified flood-tolerant woody competitors in the seedbank and re-sprouting as impediments to the establishment of desired herbaceous wetland vegetation communities. We restored 3 bays on the Savannah River Site, South Carolina, by plugging drainage ditches, harvesting residual pine/hardwood stands within the bays, and monitoring the vegetative response of the seedbank to the hydrologic change. We applied a foliar herbicide on one-half of each bay to control red maple (Acerrubrum), sweetgum (Liquidambar styraciflua), and water oak (Quercus nigra) sprouting, and we tested its effectiveness across a hydrologic gradient in each bay. Hardwood regeneration was partially controlled by flooding in bays that exhibited long growing season hydroperiods. The findings also indicated that herbicide application was an effective means for managing hardwood regeneration and re-sprouting in areas where hydrologic control was ineffective. Herbicide use had no effect on species richness in the emerging vegetation community. In late-season drawdown periods, or in bays where hydroperiods are short, more than one herbicide application may be necessary.

  10. MODELING THE 1958 LITUYA BAY MEGA-TSUNAMI, II

    Directory of Open Access Journals (Sweden)

    Charles L. Mader

    2002-01-01

    Full Text Available Lituya Bay, Alaska is a T-Shaped bay, 7 miles long and up to 2 miles wide. The two arms at the head of the bay, Gilbert and Crillon Inlets, are part of a trench along the Fairweather Fault. On July 8, 1958, an 7.5 Magnitude earthquake occurred along the Fairweather fault with an epicenter near Lituya Bay.A mega-tsunami wave was generated that washed out trees to a maximum altitude of 520 meters at the entrance of Gilbert Inlet. Much of the rest of the shoreline of the Bay was denuded by the tsunami from 30 to 200 meters altitude.In the previous study it was determined that if the 520 meter high run-up was 50 to 100 meters thick, the observed inundation in the rest of Lituya Bay could be numerically reproduced. It was also concluded that further studies would require full Navier-Stokes modeling similar to those required for asteroid generated tsunami waves.During the Summer of 2000, Hermann Fritz conducted experiments that reproduced the Lituya Bay 1958 event. The laboratory experiments indicated that the 1958 Lituya Bay 524 meter run-up on the spur ridge of Gilbert Inlet could be caused by a landslide impact.The Lituya Bay impact landslide generated tsunami was modeled with the full Navier- Stokes AMR Eulerian compressible hydrodynamic code called SAGE with includes the effect of gravity.

  11. Coastal Habitat Restoration and Hydrodynamics in Panguil Bay, Philippines

    Science.gov (United States)

    Roxas, P. G.; Gorospe, J. G.

    2007-03-01

    Hydrobiological studies indicate the deterioration of the coastal ecosystems in Panguil Bay, Philippines despite interventions that started more than a decade ago. Mangrove ecosystems that filter land run offs and act as pollutant sinks are converted to fishponds that discharge toxic materials into the bay. Monsoon winds continue to erode mangrove-dominated coastlines. Water movements, nutrient transport and influx of freshwater from rivers and saline waters from the sea are altered by proliferating fishing structures and boats that use sea lanes for navigation. The reduction of current velocities increased siltation rates that caused shallowing of the bay. Failure in interventions to restore ecosystems is partly attributed to use of methods that failed to consider the bay's hydrodynamics. But sustaining the bay is a must because it is a major source of fishery resources hence strategies to arrest its further deterioration and to rehabilitate the degraded ecosystems based on the bay's hydrodynamics are explored. Timing, selection of appropriate species, and use of encasements are considered relative to the water dynamics of the bay. Zoning and regulation of barrier structures are implemented in some parts of the bay. Bioremediating agricultural run offs and discharges from fishponds, boats, and factories that accumulate in the inner part of the bay remains a challenge.

  12. PENERAPAN ALGORITMA NAIVE BAYES UNTUK MENGKLASIFIKASI DATA NASABAH ASURANSI

    Directory of Open Access Journals (Sweden)

    Bustami Bustami

    2014-01-01

    Full Text Available Data mining adalah teknik yang memanfaatkan data dalam jumlah yang besar untuk memperoleh informasi berharga yang sebelumnya tidak diketahui dan dapat dimanfaatkan untuk pengambilan keputusan penting. Pada penelitian ini, penulis berusaha menambang data (data mining nasabah sebuah perusahaan asuransi untuk mengetahui lancar, kurang lancar atau tidak lancarnya nasabah tersebut. Data yang ada dianalisis menggunakan algoritma Naive Bayes. Naive Bayes merupakan salah satu meode pada probabilistic reasoning. Algoritma Naive Bayes bertujuan untuk melakukan klasifikasi data pada kelas tertentu, kemudian pola tersebut dapat digunakan untuk memperkirakan nasabah yang bergabung, sehingga perusahaan bisa mengambil keputusan menerima atau menolak calon nasabah tersebut. Kata Kunci : data mining, asuransi, klasifikasi, algoritma Naive Bayes

  13. A summer monsoon pump to keep the Bay of Bengal salty

    Digital Repository Service at National Institute of Oceanography (India)

    Vinayachandran, P.N.; Shankar, D.; Vernekar, S.; Sandeep, K.K.; Amol, P.; Neema, C.P.; Chatterjee, A.

    The Bay of Bengal receives a large influx of freshwater from precipitation and river discharge. Outflow of excess freshwater and inflow of saltier water is required to prevent the bay from freshening. Relatively fresh water flows out of the bay...

  14. Sediment depositional environment in some bays in Central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Rajamanickam, G.V.; Gujar, A.R.

    minerals data show a positive correlation with mean grain size in Kalbadevi Bay but negative correlation in Ratnagiri Bay, whereas they show an unharmonic relationship with sorting. Considering similar hydraulic conditions in all the bays, the existence...

  15. San Francisco Bay National Wildlife Refuge Complex Annual Narrative Report 1981

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The San Francisco Bay National Wildlife Refuge Complex comprises of three refuges including the San Francisco Bay National Wildlife Refuge, the San Pablo Bay...

  16. On watermass mixing ratios and regenerated silicon in the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, D.P.; Sarma, V.V.; Rao, V.S.; Sudhakar, U.; Gupta, G.V.M.

    Regeneration of silicon on mixing in the Bay of Bengal have been computed from six water masses [Bay of Bengal low saline water (BBLS), Bay of Bengal subsurface water (BBSS), northern southeast high salinity water (NSEHS), north Indian intermediate...

  17. San Francisco Bay National Wildlife Refuge Complex Annual Narrative Report 1983

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The San Francisco Bay National Wildlife Refuge Complex comprises of three refuges including the San Francisco Bay National Wildlife Refuge, the San Pablo Bay...

  18. San Francisco Bay National Wildlife Refuge Complex Annual Narrative Report 1979

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The San Francisco Bay National Wildlife Refuge Complex comprises of three refuges including the San Francisco Bay National Wildlife Refuge, the San Pablo Bay...

  19. San Francisco Bay National Wildlife Refuge Complex Annual Narrative Report 1977

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The San Francisco Bay National Wildlife Refuge Complex comprises of three refuges including the San Francisco Bay National Wildlife Refuge, the San Pablo Bay...

  20. Field Exploration of Methane Seep Near Atqasuk

    Energy Technology Data Exchange (ETDEWEB)

    Katey Walter, Dennis Witmer, Gwen Holdmann

    2008-12-31

    Methane (CH{sub 4}) in natural gas is a major energy source in the U.S., and is used extensively on Alaska's North Slope, including the oilfields in Prudhoe Bay, the community of Barrow, and the National Petroleum Reserve, Alaska (NPRA). Smaller villages, however, are dependent on imported diesel fuel for both power and heating, resulting in some of the highest energy costs in the U.S. and crippling local economies. Numerous CH{sub 4} gas seeps have been observed on wetlands near Atqasuk, Alaska (in the NPRA), and initial measurements have indicated flow rates of 3,000-5,000 ft{sup 3} day{sup -1} (60-100 kg CH{sub 4} day{sup -1}). Gas samples collected in 1996 indicated biogenic origin, although more recent sampling indicated a mixture of biogenic and thermogenic gas. In this study, we (1) quantified the amount of CH{sub 4} generated by several seeps and evaluated their potential use as an unconventional gas source for the village of Atqasuk; (2) collected gas and analyzed its composition from multiple seeps several miles apart to see if the source is the same, or if gas is being generated locally from isolated biogenic sources; and (3) assessed the potential magnitude of natural CH{sub 4} gas seeps for future use in climate change modeling.

  1. UAS measurements of ice fog and diamond dust in the Arctic at the DOE ARM mobile facility of Oliktok Point, Alaska

    Science.gov (United States)

    Schmitt, C. G.; Stuefer, M.; Heymsfield, A.

    2013-12-01

    We report on our planned airborne studies of ice fog and diamond dust at the DOE Atmospheric Radiation Measurement (ARM) mobile facility at Oliktok Point, Alaska. Measurements are proposed with a newly developed small version of a Video-Ice Particle Sampler (VIPS) as well as ice crystal replicators; the instruments will be flown aboard a hexacopter type unmanned aerial system (UAS). The UAS will operate at favorable low wind situations within an altitude range of approximate 3000 feet from the surface. Ice fog and diamond dust have been observed up to 50% of all winter days at selected locations in the Arctic. Strong surface-based temperature inversions form during the Arctic winter months from November to May as an effect of the low solar energy received at the surface. The cold and very stable boundary layer inhibits vertical aerosol exchange processes with the free atmosphere, which leads to continuous formation and accumulation of atmospheric ice crystals. Vertical changes in particle numbers, type, and size distribution will provide a wealth of new information about the properties and variability of low level Arctic ice aerosol. Additional continuous ground based cloud particle measurements will allow evaluation of temporal changes of the ice crystals. A goal of the study is to evaluate regional anthropogenic and natural effects on ice fog microphysics. Oliktok Point is located along the typical short-range trajectories of industrial pollutants (~30 miles northwest of the Prudhoe Bay Oilfields). Differences in ice particle microphysics and nuclei characteristics will allow evaluation of regional anthropogenic effects.

  2. Improved geomagnetic referencing in the Arctic environment

    Science.gov (United States)

    Poedjono, B.; Beck, N.; Buchanan, A. C.; Borri, L.; Maus, S.; Finn, Carol; Worthington, E. William; White, Tim

    2016-01-01

    Geomagnetic referencing uses the Earth’s magnetic field to determine accurate wellbore positioning essential for success in today's complex drilling programs, either as an alternative or a complement to north-seeking gyroscopic referencing. However, fluctuations in the geomagnetic field, especially at high latitudes, make the application of geomagnetic referencing in those areas more challenging. Precise crustal mapping and the monitoring of real-time variations by nearby magnetic observatories is crucial to achieving the required geomagnetic referencing accuracy. The Deadhorse Magnetic Observatory (DED), located at Prudhoe Bay, Alaska, has already played a vital role in the success of several commercial ventures in the area, providing essential, accurate, real-time data to the oilfield drilling industry. Geomagnetic referencing is enhanced with real-time data from DED and other observatories, and has been successfully used for accurate wellbore positioning. The availability of real-time geomagnetic measurements leads to significant cost and time savings in wellbore surveying, improving accuracy and alleviating the need for more expensive surveying techniques. The correct implementation of geomagnetic referencing is particularly critical as we approach the increased activity associated with the upcoming maximum of the 11-year solar cycle. The DED observatory further provides an important service to scientific communities engaged in studies of ionospheric, magnetospheric and space weather phenomena.

  3. Gateway National Recreation Area, Jamaica Bay Unit : Jamaica Bay Greenway Missing Links Study.

    Science.gov (United States)

    2010-09-24

    Based on both a field site reconnaissance and workshop, this study developed a conceptual plan for the location and design of bicyle facilites to complete a "missing link" of the Jamaica Bay through the Rockaway region of Brooklyn and Queens in New Y...

  4. Management case study: Tampa Bay, Florida

    Science.gov (United States)

    Morrison, Gerold; Greening, Holly; Yates, Kimberly K.; Wolanski, Eric; McLusky, Donald S.

    2011-01-01

    Tampa Bay, Florida, USA, is a shallow, subtropical estuary that experienced severe cultural eutrophication between the 1940s and 1980s, a period when the human population of its watershed quadrupled. In response, citizen action led to the formation of a public- and private-sector partnership (the Tampa Bay Estuary Program), which adopted a number of management objectives to support the restoration and protection of the bay’s living resources. These included numeric chlorophyll a and water-clarity targets, as well as long-term goals addressing the spatial extent of seagrasses and other selected habitat types, to support estuarine-dependent faunal guilds. Over the past three decades, nitrogen controls involving sources such as wastewater treatment plants, stormwater conveyance systems, fertilizer manufacturing and shipping operations, and power plants have been undertaken to meet these and other management objectives. Cumulatively, these controls have resulted in a 60% reduction in annual total nitrogen (TN) loads relative to earlier worse-case (latter 1970s) conditions. As a result, annual water-clarity and chlorophyll a targets are currently met in most years, and seagrass cover measured in 2008 was the highest recorded since 1950. Factors that have contributed to the observed improvements in Tampa Bay over the past several decades include the following: (1) Development of numeric, science-based water-quality targets to meet a long-term goal of restoring seagrass acreage to 1950s levels. Empirical and mechanistic models found that annual average chlorophyll a concentrations were a primary manageable factor affecting light attenuation. The models also quantified relationships between TN loads, chlorophyll a concentrations, light attenuation, and fluctuations in seagrass cover. The availability of long-term monitoring data, and a systematic process for using the data to evaluate the effectiveness of management actions, has allowed managers to track progress and

  5. Commencement Bay Study. Volume IV. Invertebrates.

    Science.gov (United States)

    1981-12-31

    AD-AI12 555 DAMES AND MOORE SEATTLE WA* FIG 8/1 COMMENCEMENT BAY STUDY. VOLUME IV. INVERTEBRATES .(U)DEC 81 W M BAYLOCK, J P HOUGHTON DACW67-80-C-OIDI...December 1981 Volume IV, Invertebrates 6. PERFORMINO ORG. REPORT NUMBER 682-021-05 7. AUTHOR(*) S. CONTRACT OR GRANT NUmaER(S) DACW67-80-C-0101 S. PERFORMING... Invertebrates Air Quality, Birds Is. KEY WORDS (Continue an reverse old. It necomemy w red ty a b eek mireber) Salmonids Wetlands Noise Aesthetics Marine Fish

  6. Bathymetry and acoustic backscatter: Estero Bay, California

    Science.gov (United States)

    Hartwell, Stephen R.; Finlayson, David P.; Dartnell, Peter; Johnson, Samuel Y.

    2013-01-01

    Between July 30 and August 9, 2012, scientists from the U.S. Geological Survey (USGS), Pacific Coastal and Marine Science Center (PCMSC), acquired bathymetry and acoustic-backscatter data from Estero Bay, San Luis Obispo, California, under PCMSC Field Activity ID S-05-12-SC. The survey was done using the R/V Parke Snavely outfitted with a multibeam sonar for swath mapping and highly accurate position and orientation equipment for georeferencing. This report provides these data in a number of different formats, as well as a summary of the mapping mission, maps of bathymetry and backscatter, and Federal Geographic Data Committee (FGDC) metadata.

  7. Minimum relative entropy, Bayes and Kapur

    Science.gov (United States)

    Woodbury, Allan D.

    2011-04-01

    The focus of this paper is to illustrate important philosophies on inversion and the similarly and differences between Bayesian and minimum relative entropy (MRE) methods. The development of each approach is illustrated through the general-discrete linear inverse. MRE differs from both Bayes and classical statistical methods in that knowledge of moments are used as ‘data’ rather than sample values. MRE like Bayes, presumes knowledge of a prior probability distribution and produces the posterior pdf itself. MRE attempts to produce this pdf based on the information provided by new moments. It will use moments of the prior distribution only if new data on these moments is not available. It is important to note that MRE makes a strong statement that the imposed constraints are exact and complete. In this way, MRE is maximally uncommitted with respect to unknown information. In general, since input data are known only to within a certain accuracy, it is important that any inversion method should allow for errors in the measured data. The MRE approach can accommodate such uncertainty and in new work described here, previous results are modified to include a Gaussian prior. A variety of MRE solutions are reproduced under a number of assumed moments and these include second-order central moments. Various solutions of Jacobs & van der Geest were repeated and clarified. Menke's weighted minimum length solution was shown to have a basis in information theory, and the classic least-squares estimate is shown as a solution to MRE under the conditions of more data than unknowns and where we utilize the observed data and their associated noise. An example inverse problem involving a gravity survey over a layered and faulted zone is shown. In all cases the inverse results match quite closely the actual density profile, at least in the upper portions of the profile. The similar results to Bayes presented in are a reflection of the fact that the MRE posterior pdf, and its mean

  8. Intertidal sediments and benthic animals of Roebuck Bay, Western Australia

    NARCIS (Netherlands)

    Pepping, M.; Piersma, T.; Pearson, G.; Lavaleye, M.

    1999-01-01

    Roebuck Bay near Broome (NW Australia) is with itsextensive tidal flats one of the foremost internationallyimportant sites for shorebirds in the Asia-Pacificflyway system. It is home to 150,000 shorebirds (or‘waders’) in the nonbreeding season, which suggeststhat the intertidal flats of the bay have

  9. Summer survival of Phytophthora ramorum in California bay laurel leaves

    Science.gov (United States)

    Elizabeth J. Fichtner; David M. Rizzo; Shannon C. Lynch; Jennifer Davidson; Gerri Buckles; Jennifer Parker

    2008-01-01

    Sudden oak death manifests as non-lethal foliar lesions on bay laurel (Umbellularia californica), which support sporulation and survival of Phytophthora ramorum in forest ecosystems. Infected bay laurel leaves are more likely to abscise than uninfected leaves, resulting in an accumulation of inoculum at the forest floor. The pathogen survives the dry...

  10. 33 CFR 117.795 - Jamaica Bay and Connecting Waterways.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Jamaica Bay and Connecting Waterways. 117.795 Section 117.795 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New York § 117.795 Jamaica Bay and...

  11. St Helena Bay (southern Benguela) then and now: muted climate ...

    African Journals Online (AJOL)

    ... the abiotic and biotic components. St Helena Bay in the 1950s showed similarities to 2000–2010 in terms of wind patterns, hydrology and phytoplankton. Upwelling, oxygen and nutrient concentrations in subthermocline water displayed pronounced decadal-scale variability. Primary production in St Helena Bay is variable ...

  12. Flood Risk Mitigation for the Jamaica Bay Area

    NARCIS (Netherlands)

    Aarnink, J.L.; De Boer, R.; Evers, G.A.; Kruis, M.C.; Van der Valk, K.

    2014-01-01

    Project Jamaica Bay is a response to superstorm Sandy, occurring in October, 2012. The storm was a disaster for New York City, causing around 50 billion US dollars of damage. Research shows that 75% of the expected annual dam-age in New York occurs around the Jamaica Bay area. Another problem that

  13. An overview of the Daya Bay Reactor Neutrino Experiment

    CERN Document Server

    Cao, Jun

    2016-01-01

    The Daya Bay Reactor Neutrino Experiment discovered an unexpectedly large neutrino oscillation related to the mixing angle $\\theta_{13}$ in 2012. This finding paved the way to the next generation of neutrino oscillation experiments. In this article, we review the history, featured design, and scientific results of Daya Bay. Prospects of the experiment are also described.

  14. An overview of the Daya Bay reactor neutrino experiment

    OpenAIRE

    Cao, Jun; Luk, Kam-Biu

    2016-01-01

    The Daya Bay Reactor Neutrino Experiment discovered an unexpectedly large neutrino oscillation related to the mixing angle $\\theta_{13}$ in 2012. This finding paved the way to the next generation of neutrino oscillation experiments. In this article, we review the history, featured design, and scientific results of Daya Bay. Prospects of the experiment are also described.

  15. Modelling of hydrodynamic circulation in Benoa Bay, Bali

    DEFF Research Database (Denmark)

    Ningsih, Nining Sari; Muchamad, Al Azhar

    2013-01-01

    A simulation of water level, velocity, salinity, and temperature in the Bay of Benoa has been carried out using a three-dimensional hydrodynamic Estuarine and Coastal Ocean Model incorporating a main characteristic of southward transport of the Indonesian throughflow at the offshore area of the bay...

  16. eBay's Business Format: An example of Participatory Democracy ...

    African Journals Online (AJOL)

    Here, I analyzed the eBay business model and compared the user agreements and texts among eBay, Sothebys, PayPal and Paisa Pay. Further, an analysis of Indian jurisprudence on online auctioneer liability and the subsequent legislation was performed to determine the impact of the business model on a developing ...

  17. A support system for predicting eBay end prices.

    NARCIS (Netherlands)

    D.P. van Heijst (Dennis); R. Potharst (Rob); M.C. van Wezel (Michiel)

    2006-01-01

    textabstractIn this report a support system for predicting end prices on eBay is proposed. The end price predictions are based on the item descriptions found in the item listings of eBay, and on some numerical item features. The system uses text mining and boosting algorithms from the field of

  18. 27 CFR 9.157 - San Francisco Bay.

    Science.gov (United States)

    2010-04-01

    ..., San Mateo, Santa Clara, Alameda, and Contra Costa, which border the San Francisco Bay. The area also... proceed along the San Francisco, San Mateo, and Santa Cruz County shoreline (across the Quadrangles of San... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false San Francisco Bay. 9.157...

  19. 33 CFR 80.110 - Casco Bay, ME.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Casco Bay, ME. 80.110 Section 80.110 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Atlantic Coast § 80.110 Casco Bay, ME. (a) A line drawn from the...

  20. Characteristic mixing triangles in the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Varkey, M.J.; Sastry, J.S.

    Temperature-salinity structures in the inner part of Bay of Bengal showed complete mixing processes in the upper bay, less than about 600 m can be characterisEd. by a mixing triangle constitutEd. by three characteristic water properties. In outer...

  1. 33 CFR 334.80 - Narragansett Bay, RI; restricted area.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Narragansett Bay, RI; restricted..., DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.80 Narragansett Bay, RI; restricted... regulations in this section shall be enforced by the Commander U.S. Naval Base, Newport, RI, and such agencies...

  2. Using naive Bayes classifier for classification of convective rainfall ...

    Indian Academy of Sciences (India)

    ... based on 'naiveBayes classifier' is applied. This is a simple probabilistic classifier based on applying 'Bayes' theoremwith strong (naive) independent assumptions. For a 9-month period, the ability of SEVIRI to classifythe rainfall intensity in the convective clouds is evaluated using weather radar over the northern Algeria.

  3. Great Knot Calidris tenuirostris at Lutembe Bay, Uganda

    African Journals Online (AJOL)

    Lutembe bay is a sheltered shallow bay on the northern shores of Lake Victoria near. Entebbe International Airport with scattered mud islands often covered by water hyacinth. It has many Palaearctic migrants, particularly huge congregations of gulls and terns. Interesting species such as Caspian Tern Sterna caspia, ...

  4. Upwelling features near Sri Lanka in the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    ShreeRam, P.; Rao, L.V.G.

    The Bay of Bengal is a semi-enclosed tropical ocean basin that is highly influenced by monsoons and receives large volume of freshwater from both river discharge and rainfall. Over the Bay of Bengal two distinct wind systems prevail during the year...

  5. 33 CFR 110.193 - Tampa Bay, Fla.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Tampa Bay, Fla. 110.193 Section 110.193 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.193 Tampa Bay, Fla. (a) The anchorage grounds—(1) Explosives...

  6. 33 CFR 110.193a - St. Joseph Bay, Fla.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false St. Joseph Bay, Fla. 110.193a Section 110.193a Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.193a St. Joseph Bay, Fla. (a) The anchorage grounds—(1...

  7. Dynamics of macrozoobenthos assemblages in the Fubao Bay of ...

    African Journals Online (AJOL)

    A two-year-long investigation on the dynamics of the structure and biodiversity of macrozoobenthos was conducted in the Fubao Bay of Dianchi Lake, Southwest China. A high level of organic pollution has been detected in this Bay for the last 10 years. In all, 31 benthic taxa belonging to eight families and 20 genera were ...

  8. 33 CFR 117.779 - Eastchester Bay (Arm of).

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Eastchester Bay (Arm of). 117.779 Section 117.779 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New York § 117.779 Eastchester Bay (Arm of). The draw...

  9. 46 CFR 7.110 - Mamala Bay, HI.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Mamala Bay, HI. 7.110 Section 7.110 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES APPLICABLE TO THE PUBLIC BOUNDARY LINES Hawaii § 7.110 Mamala Bay, HI. A line drawn from Barbers Point Light to Diamond Head Light. Pacific Coast ...

  10. 33 CFR 80.1430 - Kaneohe Bay, Oahu, HI.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Kaneohe Bay, Oahu, HI. 80.1430 Section 80.1430 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Islands § 80.1430 Kaneohe Bay, Oahu, HI. A straight line...

  11. 33 CFR 80.1420 - Mamala Bay, Oahu, HI.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Mamala Bay, Oahu, HI. 80.1420 Section 80.1420 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Islands § 80.1420 Mamala Bay, Oahu, HI. A line drawn from...

  12. Green Bay: Spatial patterns in water quality and landscape correlations

    Science.gov (United States)

    We conducted a high-resolution survey along the nearshore (369 km) in Green Bay using towed electronic instrumentation at approximately the 15 m depth contour, with additional transects of the bay that were oriented cross-contour (49 km). Electronic sensor data provided an effic...

  13. Optimasi Naive Bayes Dengan Pemilihan Fitur Dan Pembobotan Gain Ratio

    Directory of Open Access Journals (Sweden)

    I Guna Adi Socrates

    2016-03-01

    Full Text Available Naïve Bayes merupakan salah satu metode data mining yang umum digunakan dalam klasifikasi dokumen berbasis text. Kelebihan dari metode ini adalah algoritma yang sederhana dengan  kompleksitas  perhitungan  yang  rendah.  Akan  tetapi,  pada  metode  Naïve  Bayes terdapat kelemahan dimana sifat independensi dari fitur Naïve Bayes tidak dapat selalu diterapkan sehingga akan berpengaruh pada tingkat akurasi perhitungan. Maka dari itu, metode Naïve Bayes perlu dioptimasi dengan cara pemberian bobot mengunakan Gain Ratio. Namun, pemberian bobot pada Naïve Bayes menimbulkan permasalahan pada penghitungan probabilitas setiap    dokumen, dimana fitur  yang tidak  merepresentasikan kelas  yang diuji banyak muncul sehingga terjadi kesalahan klasifikasi. Oleh karena itu, pembobotan Naïve Bayes   masih   belum   optimal.   Paper   ini mengusulkan  optimasi  metode   Naïve   Bayes mengunakan pembobotan Gain Ratio yang ditambahkan dengan metode pemilihan fitur pada kasus klasifikasi teks. Hasil penelitian ini menunjukkan bahwa optimasi metode Naïve Bayes menggunakan pemilihan fitur dan pembobotan menghasilkan akurasi sebesar 94%.

  14. Hydrodynamics and water quality models applied to Sepetiba Bay

    Science.gov (United States)

    Cunha, Cynara de L. da N.; Rosman, Paulo C. C.; Ferreira, Aldo Pacheco; Carlos do Nascimento Monteiro, Teófilo

    2006-10-01

    A coupled hydrodynamic and water quality model is used to simulate the pollution in Sepetiba Bay due to sewage effluent. Sepetiba Bay has a complicated geometry and bottom topography, and is located on the Brazilian coast near Rio de Janeiro. In the simulation, the dissolved oxygen (DO) concentration and biochemical oxygen demand (BOD) are used as indicators for the presence of organic matter in the body of water, and as parameters for evaluating the environmental pollution of the eastern part of Sepetiba Bay. Effluent sources in the model are taken from DO and BOD field measurements. The simulation results are consistent with field observations and demonstrate that the model has been correctly calibrated. The model is suitable for evaluating the environmental impact of sewage effluent on Sepetiba Bay from river inflows, assessing the feasibility of different treatment schemes, and developing specific monitoring activities. This approach has general applicability for environmental assessment of complicated coastal bays.

  15. Study on bayes discriminant analysis of EEG data.

    Science.gov (United States)

    Shi, Yuan; He, DanDan; Qin, Fang

    2014-01-01

    In this paper, we have done Bayes Discriminant analysis to EEG data of experiment objects which are recorded impersonally come up with a relatively accurate method used in feature extraction and classification decisions. In accordance with the strength of α wave, the head electrodes are divided into four species. In use of part of 21 electrodes EEG data of 63 people, we have done Bayes Discriminant analysis to EEG data of six objects. Results In use of part of EEG data of 63 people, we have done Bayes Discriminant analysis, the electrode classification accuracy rates is 64.4%. Bayes Discriminant has higher prediction accuracy, EEG features (mainly αwave) extract more accurate. Bayes Discriminant would be better applied to the feature extraction and classification decisions of EEG data.

  16. Crustal structure of Bristol Bay Region, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, A.K.; McLean, H.; Marlow, M.S.

    1985-04-01

    Bristol Bay lies along the northern side of the Alaska Peninsula and extends nearly 600 km southwest from the Nushagak lowlands on the Alaska mainland to near Unimak Island. The bay is underlain by a sediment-filled crustal downwarp known as the north Aleutian basin (formerly Bristol basin) that dips southeast toward the Alaska Peninsula and is filled with more than 6 km of strata, dominantly of Cenozoic age. The thickest parts of the basin lie just north of the Alaska Peninsula and, near Port Mollar, are in fault contact with older Mesozoic sedimentary rocks. These Mesozoic rocks form the southern structural boundary of the basin and extend as an accurate belt from at least Cook Inlet to Zhemchug Canyon (central Beringian margin). Offshore multichannel seismic-reflection, sonobuoy seismic-refraction, gravity, and magnetic data collected by the USGS in 1976 and 1982 indicate that the bedrock beneath the central and northern parts of the basin comprises layered, high-velocity, and highly magnetic rocks that are locally deformed. The deep bedrock horizons may be Mesozoic(.) sedimentary units that are underlain by igneous or metamorphic rocks and may correlate with similar rocks of mainland western Alaska and the Alaska Peninsula. Regional structural and geophysical trends for these deep horizons change from northeast-southwest to northwest-southeast beneath the inner Bering shelf and may indicate a major crustal suture along the northern basin edge.

  17. Master Agreement Between Bay de Noc Community College Governing Board and Bay de Noc Community College Faculty Association.

    Science.gov (United States)

    Bay de Noc Community Coll., Escanaba, MI.

    This agreement between the Bay de Noc Community College Governing Board and the Bay de Noc Community College Faculty Association covers the period from 1973-75. Contents cover recognition, rights, and guarantees; faculty, personnel, and division procedures; appointments, promotions, reductions, and related matters; leaves and absences; grievance…

  18. A Comparative Study of Bayes Net, Naive Bayes and Averaged One-Dependence Estimators for Osteoporosis Analysis.

    Science.gov (United States)

    Waleska Simões, Priscyla; Mazzuchello, Leandro Luiz; Toniazzo de Abreu, Larissa Letieli; Garcia, Diego; dos Passos, Maitê Gabriel; Venson, Ramon; Bisognin Ceretta, Luciane; Veiga Silva, Ana Carolina; da Rosa, Maria Inês; Martins, Paulo João

    2015-01-01

    This paper presents an evaluation of the accuracy of the Bayesian classifiers: Bayes Net, Naive Bayes and Averaged One-Dependence Estimator, to support diagnoses of osteopenia and osteoporosis. All classifiers showed good results, thus, given data, it is possible to produce a reasonably accurate estimate of the diagnosis.

  19. ASTER Images San Francisco Bay Area

    Science.gov (United States)

    2000-01-01

    These images of the San Francisco Bay region were acquired on March 3, 2000 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. Each covers an area 60 kilometers (37 miles) wide and 75 kilometers (47 miles) long. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER will image the Earth for the next 6 years to map and monitor the changing surface of our planet.Upper Left: The color infrared composite uses bands in the visible and reflected infrared. Vegetation is red, urban areas are gray; sediment in the bays shows up as lighter shades of blue. Thanks to the 15 meter (50-foot) spatial resolution, shadows of the towers along the Bay Bridge can be seen.Upper right: A composite of bands in the short wave infrared displays differences in soils and rocks in the mountainous areas. Even though these regions appear entirely vegetated in the visible, enough surface shows through openings in the vegetation to allow the ground to be imaged.Lower left: This composite of multispectral thermal bands shows differences in urban materials in varying colors. Separation of materials is due to differences in thermal emission properties, analogous to colors in the visible.Lower right: This is a color coded temperature image of water temperature, derived from the thermal bands. Warm waters are in white and yellow, colder waters are blue. Suisun Bay in the upper right is fed directly from the cold Sacramento River. As the water flows through San Pablo and San Francisco Bays on the way to the Pacific, the waters warm up.Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for

  20. GPU MrBayes V3.1: MrBayes on Graphics Processing Units for Protein Sequence Data.

    Science.gov (United States)

    Pang, Shuai; Stones, Rebecca J; Ren, Ming-Ming; Liu, Xiao-Guang; Wang, Gang; Xia, Hong-ju; Wu, Hao-Yang; Liu, Yang; Xie, Qiang

    2015-09-01

    We present a modified GPU (graphics processing unit) version of MrBayes, called ta(MC)(3) (GPU MrBayes V3.1), for Bayesian phylogenetic inference on protein data sets. Our main contributions are 1) utilizing 64-bit variables, thereby enabling ta(MC)(3) to process larger data sets than MrBayes; and 2) to use Kahan summation to improve accuracy, convergence rates, and consequently runtime. Versus the current fastest software, we achieve a speedup of up to around 2.5 (and up to around 90 vs. serial MrBayes), and more on multi-GPU hardware. GPU MrBayes V3.1 is available from http://sourceforge.net/projects/mrbayes-gpu/. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Integrating science and resource management in Tampa Bay, Florida

    Science.gov (United States)

    Yates, Kimberly K.; Greening, Holly; Morrison, Gerold

    2011-01-01

    Tampa Bay is recognized internationally for its remarkable progress towards recovery since it was pronounced "dead" in the late 1970s. Due to significant efforts by local governments, industries and private citizens throughout the watershed, water clarity in Tampa Bay is now equal to what it was in 1950, when population in the watershed was less than one-quarter of what it is today. Seagrass extent has increased by more than 8,000 acres since the mid-1980s, and fish and wildlife populations are increasing. Central to this successful turn-around has been the Tampa Bay resource management community's long-term commitment to development and implementation of strong science-based management strategies. Research institutions and agencies, including Eckerd College, the Florida Wildlife Commission Fish and Wildlife Research Institute, Mote Marine Laboratory, National Oceanic and Atmospheric Administration, the Southwest Florida Water Management District, University of South Florida, U.S. Environmental Protection Agency, U.S. Geological Survey, local and State governments, and private companies contribute significantly to the scientific basis of our understanding of Tampa Bay's structure and ecological function. Resource management agencies, including the Tampa Bay Regional Planning Council's Agency on Bay Management, the Southwest Florida Water Management District's Surface Water Improvement and Management Program, and the Tampa Bay Estuary Program, depend upon this scientific basis to develop and implement regional adaptive management programs. The importance of integrating science with management has become fully recognized by scientists and managers throughout the region, State and Nation. Scientific studies conducted in Tampa Bay over the past 10–15 years are increasingly diverse and complex, and resource management programs reflect our increased knowledge of geology, hydrology and hydrodynamics, ecology and restoration techniques. However, a synthesis of this

  2. Bay breeze climatology at two sites along the Chesapeake bay from 1986-2010: Implications for surface ozone.

    Science.gov (United States)

    Stauffer, Ryan M; Thompson, Anne M

    Hourly surface meteorological measurements were coupled with surface ozone (O3) mixing ratio measurements at Hampton, Virginia and Baltimore, Maryland, two sites along the Chesapeake Bay in the Mid-Atlantic United States, to examine the behavior of surface O3 during bay breeze events and quantify the impact of the bay breeze on local O3 pollution. Analyses were performed for the months of May through September for the years 1986 to 2010. The years were split into three groups to account for increasingly stringent environmental regulations that reduced regional emissions of nitrogen oxides (NOx): 1986-1994, 1995-2002, and 2003-2010. Each day in the 25-year record was marked either as a bay breeze day, a non-bay breeze day, or a rainy/cloudy day based on the meteorological data. Mean eight hour (8-h) averaged surface O3 values during bay breeze events were 3 to 5 parts per billion by volume (ppbv) higher at Hampton and Baltimore than on non-bay breeze days in all year periods. Anomalies from mean surface O3 were highest in the afternoon at both sites during bay breeze days in the 2003-2010 study period. In conjunction with an overall lowering of baseline O3 after the 1995-2002 period, the percentage of total exceedances of the Environmental Protection Agency (EPA) 75 ppbv 8-h O3 standard that occurred on bay breeze days increased at Hampton for 2003-2010, while remaining steady at Baltimore. These results suggest that bay breeze circulations are becoming more important to causing exceedance events at particular sites in the region, and support the hypothesis of Martins et al. (2012) that highly localized meteorology increasingly drives air quality events at Hampton.

  3. Lessons from monitoring water quality in San Francisco Bay

    Science.gov (United States)

    Cloern, J.E.; Schraga, T.S.; Lopez, C.B.; Labiosa, R.

    2003-01-01

    San Francisco Bay is the defining landscape feature of the place we call ‘The Bay Area,’ but most of us only experience the Bay as we view it from an airplane window or drive across one of its bridges. These views from afar suggest that the Bay is static and sterile, but this impression is deceptive. If you are one of the many thousands of students who have experienced the Bay through a school excursion with the Marine Science Institute or other educational programs, you observed its rich plankton soup under a microscope, sorted clams and worms and crustaceans from mud samples, and identified the gobies, sole, halibut, bat rays, sharks, sardines, and smelt caught with trawls. San Francisco Bay is much more than a landscape feature. It is a dynamic ecosystem, continually changing and teeming with life. The Bay once supported the most valuable fisheries on the west coast of the United States, but commercial fishing for shellfish, shrimp, sturgeon, shad, salmon, and striped bass ended many decades ago because of habitat loss, pollution, invasive species and over harvest.

  4. Storm surge propagation in Galveston Bay during Hurricane Ike

    Science.gov (United States)

    Rego, João L.; Li, Chunyan

    2010-09-01

    We studied Hurricane Ike's storm surge along the Texas-Louisiana coast using the fully nonlinear Finite-Volume Coastal Ocean Model (FVCOM, by Chen et al., 2003) with a high-resolution unstructured mesh. The model was validated with USGS surge data collected during Hurricane Ike. This study focused on 1) how the surge wave propagates into and within Galveston Bay and 2) the importance of the bay's barrier system. Ike's coastal surge propagated alongshore due east towards Louisiana, partly because of Bolivar Peninsula, which, together with Galveston Island, provided a barrier protecting the bay. In the upper bay, a west-east oscillation of water surface gradient of about 0.08 m/km was found and studied. We then varied Bolivar Peninsula's topography for different simulations, examining the role of barrier islands on surge propagation into the bay. Results suggest that when the Peninsula's height (or volume) was reduced to about 45% of the original, with two breaches, the bay was exposed to dangerously high water levels almost as much as those if the Peninsula was leveled to just 0.05 m above the Mean Sea Level, underlining the nonlinear nature of this bay-barrier system.

  5. Deep Borehole Instrumentation Along San Francisco Bay Bridges - 2000

    Energy Technology Data Exchange (ETDEWEB)

    Hutchings, L.; Kasameyer, P.; Turpin, C.; Long, L.; Hollfelder, J.; McEvilly, T.; Clymer, R.; Uhrhammer, R.

    2000-03-01

    This is a progress report on the Bay Bridges downhole network. Between 2 and 8 instruments have been spaced along the Dumbarton, San Mateo, Bay, and San Rafael bridges in San Francisco Bay, California. The instruments will provide multiple use data that is important to geotechnical, structural engineering, and seismological studies. The holes are between 100 and 1000 ft deep and were drilled by Caltrans. There are twenty-one sensor packages at fifteen sites. The downhole instrument package contains a three component HS-1 seismometer and three orthogonal Wilcox 731 accelerometers, and is capable of recording a micro g from local M = 1.0 earthquakes to 0.5 g strong ground motion form large Bay Area earthquakes. Preliminary results on phasing across the Bay Bridge, up and down hole wave amplification at Yerba Buena Island, and sensor orientation analysis are presented. Events recorded and located during 1999 are presented. Also, a senior thesis on the deep structure of the San Francisco Bay beneath the Bay Bridge is presented as an addendum.

  6. Preparing Informal Bay Area Educators for Climate Education Success

    Science.gov (United States)

    Romero, M.

    2016-12-01

    The Bay Area Climate Literacy Impact Collaborative (Bay-CLIC) joins informal science educators from over 30 environmental education organizations with the common goal of increasing climate literacy and action. Over this past year, the collaborative has been gathering existing tools and resources that will allow informal educators in the Bay Area to communicate on climate change with confidence. Bay-CLIC's work plans to bring climate science to life by equipping educators with climate data that resonates best with local audiences, which is data that is place-based and personal. Bay-CLIC is also researching effective sustainability campaigns focused on behavior change that can be crafted to fit our unique regional context and rolled out across multiple Bay-CLIC member organizations. This session will focus on sharing our findings from our six month information gathering phase. The overarching discussion will focus on the needs that Bay Area educators identified as necessary to address in order for them to provide the best quality climate education programming. We will also discuss the data we gathered on what local educators are already using in their work and share out on how this diverse array of informal educators will be implementing our research into their programs.

  7. 36 CFR 13.1132 - What types of commercial fishing are authorized in Glacier Bay?

    Science.gov (United States)

    2010-07-01

    ... fishing are authorized in Glacier Bay? 13.1132 Section 13.1132 Parks, Forests, and Public Property...-Glacier Bay National Park and Preserve Commercial Fishing § 13.1132 What types of commercial fishing are authorized in Glacier Bay? Three types of commercial fishing are authorized in Glacier Bay non-wilderness...

  8. 77 FR 56549 - Safety Zone; Blue Angels at Kaneohe Bay Air Show, Oahu, HI

    Science.gov (United States)

    2012-09-13

    ... [Docket Number USCG-2012-0739] RIN 1625-AA00 Safety Zone; Blue Angels at Kaneohe Bay Air Show, Oahu, HI... Bay, Oahu, Hawaii. This safety zone encompasses a small area of the Kane'ohe Bay Naval [[Page 56550... capabilities, over Kaneohe Bay, Oahu, Hawaii during a 3-day period. Taking into account the hazards associated...

  9. Bayes and empirical Bayes estimators of abundance and density from spatial capture-recapture data.

    Directory of Open Access Journals (Sweden)

    Robert M Dorazio

    Full Text Available In capture-recapture and mark-resight surveys, movements of individuals both within and between sampling periods can alter the susceptibility of individuals to detection over the region of sampling. In these circumstances spatially explicit capture-recapture (SECR models, which incorporate the observed locations of individuals, allow population density and abundance to be estimated while accounting for differences in detectability of individuals. In this paper I propose two Bayesian SECR models, one for the analysis of recaptures observed in trapping arrays and another for the analysis of recaptures observed in area searches. In formulating these models I used distinct submodels to specify the distribution of individual home-range centers and the observable recaptures associated with these individuals. This separation of ecological and observational processes allowed me to derive a formal connection between Bayes and empirical Bayes estimators of population abundance that has not been established previously. I showed that this connection applies to every Poisson point-process model of SECR data and provides theoretical support for a previously proposed estimator of abundance based on recaptures in trapping arrays. To illustrate results of both classical and Bayesian methods of analysis, I compared Bayes and empirical Bayes esimates of abundance and density using recaptures from simulated and real populations of animals. Real populations included two iconic datasets: recaptures of tigers detected in camera-trap surveys and recaptures of lizards detected in area-search surveys. In the datasets I analyzed, classical and Bayesian methods provided similar - and often identical - inferences, which is not surprising given the sample sizes and the noninformative priors used in the analyses.

  10. Spatiotemporal appraisal of TBT contamination and imposex along a tropical bay (Todos os Santos Bay, Brazil).

    Science.gov (United States)

    Artifon, Vanda; Castro, Ítalo Braga; Fillmann, Gilberto

    2016-08-01

    A spatiotemporal evaluation of butyltin contamination was performed between 2010 and 2012 along Todos os Santos Bay (Northeast Brazil) using surface sediments, bivalve tissues (Anomalocardia brasiliana and Mytella guyanensis), and imposex occurrence (Stramonita rustica). The spatial study detected high tributyltin (TBT) levels (maximum values of 262 ng Sn g (-1) - 21,833 ng Sn g(-1) of total organic carbon - for surface sediments and 421 ng Sn g(-1) for bivalve tissues) in the innermost part of the bay. The TBT levels detected in M. guyanensis tissues might cause human health risk since local population consumes these organisms. These high concentrations observed in the bivalves might result in ingestions higher than the safe limits established by European Food Safety Authority (250 ng TBT kg(-1) day(-1)). Considering the temporal evaluation, no difference (p > 0.05) was observed between TBT concentrations in sediments obtained during the two sampling campaigns (2010/2011 and 2012). However, the increasing predominance of TBT metabolites (butyltin degradation index (BDI) >1) in more recent sediments indicates further degradation of old TBT inputs. In spite of that, recent inputs are still evident at this region. Nevertheless, a reduction of imposex parameters in S. rustica over the last decade suggests an overall decline in the TBT contamination, at least in the outermost and possible less impacted region of the bay. The TBT contamination is probably reducing due to the national and international legislative restrictions on the use of TBT as antifouling biocide. The contamination levels, however, are still relevant especially in the inner part of Todos os Santos Bay since they are above those that are likely to cause toxicity to the biota.

  11. Draft Detailed Project Report and Draft Environmental Assessment. Neah Bay Navigation Improvements, Neah Bay, Washington

    Science.gov (United States)

    1993-11-01

    WashinQton coastal waters. Order Carnivora Suborder Fissipedia sea otter Ehnydra lutris river otter Lutra canadensis SubcZrder Pinnipedia northern fur seal...Executive Order (EO) 11988. The requirements of EO 11988 are presented in more detail in the EA. o Preserve the wetlands in the study area in conformance with...Tribal fishermen will continue to commute from their homes in Neah Bay to Port Angeles (150 miles round trip), living there temporarily, in order to

  12. Implementation of the "Non-Local Bayes" (NL-Bayes Image Denoising Algorithm

    Directory of Open Access Journals (Sweden)

    Marc Lebrun

    2013-06-01

    Full Text Available This article presents a detailed implementation of the Non-Local Bayes (NL-Bayes image denoising algorithm. In a nutshell, NL-Bayes is an improved variant of NL-means. In the NL-means algorithm, each patch is replaced by a weighted mean of the most similar patches present in a neighborhood. Images being mostly self-similar, such instances of similar patches are generally found, and averaging them increases the SNR. The NL-Bayes strategy improves on NL-means by evaluating for each group of similar patches a Gaussian vector model. To each patch is therefore associated a mean (which would be the result of NL-means, but also a covariance matrix estimating the variability of the patch group. This permits to compute an optimal (in the sense of Bayesian minimal mean square error estimate of each noisy patch in the group, by a simple matrix inversion. The implementation proceeds in two identical iterations, but the second iteration uses the denoised image of the first iteration to estimate better the mean and covariance of the patch Gaussian models. A discussion of the algorithm shows that it is close in spirit to several state of the art algorithms (TSID, BM3D, BM3D-SAPCA, and that its structure is actually close to BM3D. Thorough experimental comparison made in this paper also shows that the algorithm achieves the best state of the art on color images in terms of PSNR and image quality. On grey level images, it reaches a performance similar to the more complex BM3D-SAPCA (no color version is available for this last algorithm.

  13. Tampa Bay Study Data and Information Management System (DIMS)

    Science.gov (United States)

    Edgar, N. T.; Johnston, J. B.; Yates, K.; Smith, K. E.

    2005-05-01

    Providing easy access to data and information is an essential component of both science and management. The Tampa Bay Data and Information Management System (DIMS) catalogs and publicizes data and products which are generated through the Tampa Bay Integrated Science Study. The publicly accessible interface consists of a Web site (http://gulfsci.usgs.gov), a digital library, and an interactive map server (IMS). The Tampa Bay Study Web site contains information from scientists involved in the study, and is also the portal site for the digital library and IMS. Study information is highlighted on the Web site according to the estuarine component: geology and geomorphology, water and sediment quality, ecosystem structure and function, and hydrodynamics. The Tampa Bay Digital Library is a web-based clearinghouse for digital products on Tampa Bay, including documents, maps, spatial and tabular data sets, presentations, etc. New developments to the digital library include new search features, 150 new products over the past year, and partnerships to expand the offering of science products. The IMS is a Web-based geographic information system (GIS) used to store, analyze and display data pertaining to Tampa Bay. Upgrades to the IMS have improved performance and speed, as well as increased the number of data sets available for mapping. The Tampa Bay DIMS is a dynamic entity and will continue to evolve with the study. Beginning in 2005, the Tampa Bay Integrated Coastal Model will have a more prominent presence within the DIMS. The Web site will feature model projects and plans; the digital library will host model products and data sets; the IMS will display spatial model data sets and analyses. These tools will be used to increase communication of USGS efforts in Tampa Bay to the public, local managers, and scientists.

  14. The Holocene History of Placentia Bay, Newfoundland

    DEFF Research Database (Denmark)

    Sheldon, Christina; Seidenkrantz, Marit-Solveig; Reynisson, Njall

    2013-01-01

    have been analyzed using several climate proxies, including benthic foraminifera, diatoms, IP25, dinoflagellate cysts and XRF. Together, these cores provide high-resolution records of the changes in climatic conditions over the last ca. 13,000 years in the southern Labrador Sea. After the Younger Dryas...... ended, the beginning of the warmer early Holocene was recorded by an increase in productivity-linked foraminiferal and diatom assemblages, as well as a drop in the presence of the sea-ice indicator IP25 in core 14G (Pearce et al., 2012). Variability in atmospheric circulation during the Holocene...... from analyses of core 10G indicate that the core contains a full Holocene record of climatic conditions in Placentia Bay inferred from foraminiferal and diatom assemblage analyses, which are expected to align with results from previous studies using the cores from the 2007 Akademik Ioffe cruise. Jessen...

  15. Benthic fluxes in San Francisco Bay

    Science.gov (United States)

    Hammond, Douglas E.; Fuller, C.; Harmon, D.; Hartman, Blayne; Korosec, M.; Miller, L.G.; Rea, R.; Warren, S.; Berelson, W.; Hager, S.W.

    1985-01-01

    Measurements of benthic fluxes have been made on four occasions between February 1980 and February 1981 at a channel station and a shoal station in South San Francisco Bay, using in situ flux chambers. On each occasion replicate measurements of easily measured substances such as radon, oxygen, ammonia, and silica showed a variability (??1??) of 30% or more over distances of a few meters to tens of meters, presumably due to spatial heterogeneity in the benthic community. Fluxes of radon were greater at the shoal station than at the channel station because of greater macrofaunal irrigation at the former, but showed little seasonal variability at either station. At both stations fluxes of oxygen, carbon dioxide, ammonia, and silica were largest following the spring bloom. Fluxes measured during different seasons ranged over factors of 2-3, 3, 4-5, and 3-10 (respectively), due to variations in phytoplankton productivity and temperature. Fluxes of oxygen and carbon dioxide were greater at the shoal station than at the channel station because the net phytoplankton productivity is greater there and the organic matter produced must be rapidly incorporated in the sediment column. Fluxes of silica were greater at the shoal station, probably because of the greater irrigation rates there. N + N (nitrate + nitrite) fluxes were variable in magnitude and in sign. Phosphate fluxes were too small to measure accurately. Alkalinity fluxes were similar at the two stations and are attributed primarily to carbonate dissolution at the shoal station and to sulfate reduction at the channel station. The estimated average fluxes into South Bay, based on results from these two stations over the course of a year, are (in mmol m-2 d-1): O2 = -27 ?? 6; TCO2 = 23 ?? 6; Alkalinity = 9 ?? 2; N + N = -0.3 ?? 0.5; NH3 = 1.4 ?? 0.2; PO4 = 0.1 ?? 0.4; Si = 5.6 ?? 1.1. These fluxes are comparable in magnitude to those in other temperate estuaries with similar productivity, although the seasonal

  16. Evaluating Bay Area Methane Emission Inventory

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Marc [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Jeong, Seongeun [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-03-01

    As a regulatory agency, evaluating and improving estimates of methane (CH4) emissions from the San Francisco Bay Area is an area of interest to the Bay Area Air Quality Management District (BAAQMD). Currently, regional, state, and federal agencies generally estimate methane emissions using bottom-up inventory methods that rely on a combination of activity data, emission factors, biogeochemical models and other information. Recent atmospheric top-down measurement estimates of methane emissions for the US as a whole (e.g., Miller et al., 2013) and in California (e.g., Jeong et al., 2013; Peischl et al., 2013) have shown inventories underestimate total methane emissions by ~ 50% in many areas of California, including the SF Bay Area (Fairley and Fischer, 2015). The goal of this research is to provide information to help improve methane emission estimates for the San Francisco Bay Area. The research effort builds upon our previous work that produced methane emission maps for each of the major source sectors as part of the California Greenhouse Gas Emissions Measurement (CALGEM) project (http://calgem.lbl.gov/prior_emission.html; Jeong et al., 2012; Jeong et al., 2013; Jeong et al., 2014). Working with BAAQMD, we evaluate the existing inventory in light of recently published literature and revise the CALGEM CH4 emission maps to provide better specificity for BAAQMD. We also suggest further research that will improve emission estimates. To accomplish the goals, we reviewed the current BAAQMD inventory, and compared its method with those from the state inventory from the California Air Resources Board (CARB), the CALGEM inventory, and recent published literature. We also updated activity data (e.g., livestock statistics) to reflect recent changes and to better represent spatial information. Then, we produced spatially explicit CH4 emission estimates on the 1-km modeling grid used by BAAQMD. We present the detailed activity data, methods and derived emission maps by sector

  17. Evaluating Manifest Monotonicity Using Bayes Factors.

    Science.gov (United States)

    Tijmstra, Jesper; Hoijtink, Herbert; Sijtsma, Klaas

    2015-12-01

    The assumption of latent monotonicity in item response theory models for dichotomous data cannot be evaluated directly, but observable consequences such as manifest monotonicity facilitate the assessment of latent monotonicity in real data. Standard methods for evaluating manifest monotonicity typically produce a test statistic that is geared toward falsification, which can only provide indirect support in favor of manifest monotonicity. We propose the use of Bayes factors to quantify the degree of support available in the data in favor of manifest monotonicity or against manifest monotonicity. Through the use of informative hypotheses, this procedure can also be used to determine the support for manifest monotonicity over substantively or statistically relevant alternatives to manifest monotonicity, rendering the procedure highly flexible. The performance of the procedure is evaluated using a simulation study, and the application of the procedure is illustrated using empirical data.

  18. bayesPop: Probabilistic Population Projections

    Directory of Open Access Journals (Sweden)

    Hana Ševčíková

    2016-12-01

    Full Text Available We describe bayesPop, an R package for producing probabilistic population projections for all countries. This uses probabilistic projections of total fertility and life expectancy generated by Bayesian hierarchical models. It produces a sample from the joint posterior predictive distribution of future age- and sex-specific population counts, fertility rates and mortality rates, as well as future numbers of births and deaths. It provides graphical ways of summarizing this information, including trajectory plots and various kinds of probabilistic population pyramids. An expression language is introduced which allows the user to produce the predictive distribution of a wide variety of derived population quantities, such as the median age or the old age dependency ratio. The package produces aggregated projections for sets of countries, such as UN regions or trading blocs. The methodology has been used by the United Nations to produce their most recent official population projections for all countries, published in the World Population Prospects.

  19. Bay street looks at the oil industry

    Energy Technology Data Exchange (ETDEWEB)

    Gaseosa, O.

    1976-04-01

    The glamour is off frontier plays and the action is among junior and intermediate producers. That's the consensus of Bay Street analysts specializing in the oil sector. The mood of the investor is one of caution. He is only paying for current earnings and dividends. Disenchantment with the majors stems from a number of factors. The rapidly escalating cost, and limited success of frontier exploration plays, lack of government policy north of 60, the high visibility, and strictures on marketing expansion. But on the positive side, regulatory approval of a Mackenzie Valley Pipeline will enable investors to ascribe specific value to Mackenzie Delta/Beaufort Sea reserves. Without regulatory approval of a pipeline these are considered speculative, despite the fact that they represent very real replacement of depleting conventional reserves. The views of several analysts are presented on other stocks in Canada and on American markets. (MCW)

  20. Lightning phenomenology in the Tampa Bay Area

    Science.gov (United States)

    Peckham, D. W.; Uman, M. A.; Wilcox, C. E., Jr.

    1984-01-01

    A commercial lightning-locating system (LLS) was employed in the study of lightning phenomenology in the Tampa Bay area of Florida. The LLS output included the time, location, number of strokes per flash, and initial peak magnetic field value of first strokes for lightning ground flashes lowering negative charge. Attention is given to the design and the operation of the LLS, and the experimental results. Measured properties of each of 111 storms are given in a number of tables. It was observed that the apparent motion associated with the lightning activity in storm systems was not due to the motion of the individual single-peak and multiple-peak storms but rather to the successive growth of new storms near previously active storms.

  1. Defining a data management strategy for USGS Chesapeake Bay studies

    Science.gov (United States)

    Ladino, Cassandra

    2013-01-01

    The mission of U.S. Geological Survey’s (USGS) Chesapeake Bay studies is to provide integrated science for improved understanding and management of the Chesapeake Bay ecosystem. Collective USGS efforts in the Chesapeake Bay watershed began in the 1980s, and by the mid-1990s the USGS adopted the watershed as one of its national place-based study areas. Great focus and effort by the USGS have been directed toward Chesapeake Bay studies for almost three decades. The USGS plays a key role in using “ecosystem-based adaptive management, which will provide science to improve the efficiency and accountability of Chesapeake Bay Program activities” (Phillips, 2011). Each year USGS Chesapeake Bay studies produce published research, monitoring data, and models addressing aspects of bay restoration such as, but not limited to, fish health, water quality, land-cover change, and habitat loss. The USGS is responsible for collaborating and sharing this information with other Federal agencies and partners as described under the President’s Executive Order 13508—Strategy for Protecting and Restoring the Chesapeake Bay Watershed signed by President Obama in 2009. Historically, the USGS Chesapeake Bay studies have relied on national USGS databases to store only major nationally available sources of data such as streamflow and water-quality data collected through local monitoring programs and projects, leaving a multitude of other important project data out of the data management process. This practice has led to inefficient methods of finding Chesapeake Bay studies data and underutilization of data resources. Data management by definition is “the business functions that develop and execute plans, policies, practices and projects that acquire, control, protect, deliver and enhance the value of data and information.” (Mosley, 2008a). In other words, data management is a way to preserve, integrate, and share data to address the needs of the Chesapeake Bay studies to better

  2. Tidal pumping - missing factor in glacial bays evolution?

    Science.gov (United States)

    Szczucinski, Witold; Moskalik, Mateusz; Dominiczak, Aleksander

    2017-04-01

    Most of the glaciers worldwide are subjected to rapid retreat. It is particularly well visible in Svalbard, where tidewater glaciers after the termination of the Little Ice Age often resulted in formation of new glacial bays. These bays are specific environments, characterised by high sediment accumulation rates, seasonal formation of sea-ice cover and common presence of icebergs. They are usually separated from the rest of the fjord by shallow (e.g. submerged moraine) or narrow passages. Although hostile, these bays also host unique ecosystems, with particular importance as feeding grounds for seals and sea birds. Among factors considered in development of such environments the role of tides is usually neglected or assumed as constant. Here we would like to stress the increasing role of tides in development of glacial bays ecosystems, as well as for import and burial of organic carbon in the bays. We present a model of tide development and results on present day conditions from Brepolen bay in Hornsund (southern Spitsbergen). On the basis of ADCP and CTD surveys we present the modern conditions and water exchange rates between the glacial bay and the fjord. Analysis of archival satellite images, aerial photographs and historical maps was used to map the change in glacial bay area. Finally simple modeling allow to identify a linear increase in tidal pumping magnitude (water exchange due to tides) with increasing glacial bay area due to glaciers retreat. We discuss it in context of potential consequences for bay oceanography, ecology and sedimentation. With fast glacier retreat and rapid grow of glacial bays one may expect the following effects of increasing tidal pumping: enhanced water exchange with the central part of the fjord, increasing salinity, facilitating colonisation by new species (e.g. import of juvenile forms of benthic species), increased input of marine organic carbon into setting suitable for its burial (high sediment accumulation rate in glacial

  3. Roebuck Bay and the Town of Broome, Western Australia, Australia

    Science.gov (United States)

    1992-01-01

    Roebuck Bay (18.0S, 122.0E) is a prominent bay on the arid northwest coast of Western Australia and the town of Broome is one of the few prominent towns along this very sparsley settled coast. The large gray area extending back from the shoreline of the bay is the Roebuck Plains slowly being filled with sediment by local streams draining the Great Sandy Desert. The irregular bare patches on the desert to the south are burn scars from brush fires.

  4. The Neoglacial landscape and human history of Glacier Bay, Glacier Bay National Park and Preserve, southeast Alaska, USA

    Science.gov (United States)

    Connor, C.; Streveler, G.; Post, A.; Monteith, D.; Howell, W.

    2009-01-01

    The Neoglacial landscape of the Huna Tlingit homeland in Glacier Bay is recreated through new interpretations of the lower Bay's fjordal geomorphology, late Quaternary geology and its ethnographic landscape. Geological interpretation is enhanced by 38 radiocarbon dates compiled from published and unpublished sources, as well as 15 newly dated samples. Neoglacial changes in ice positions, outwash and lake extents are reconstructed for c. 5500?????"200 cal. yr ago, and portrayed as a set of three landscapes at 1600?????"1000, 500?????"300 and 300?????"200 cal. yr ago. This history reveals episodic ice advance towards the Bay mouth, transforming it from a fjordal seascape into a terrestrial environment dominated by glacier outwash sediments and ice-marginal lake features. This extensive outwash plain was building in lower Glacier Bay by at least 1600 cal. yr ago, and had filled the lower bay by 500 cal. yr ago. The geologic landscape evokes the human-described landscape found in the ethnographic literature. Neoglacial climate and landscape dynamism created difficult but endurable environmental conditions for the Huna Tlingit people living there. Choosing to cope with environmental hardship was perhaps preferable to the more severely deteriorating conditions outside of the Bay as well as conflicts with competing groups. The central portion of the outwash plain persisted until it was overridden by ice moving into Icy Strait between AD 1724?????"1794. This final ice advance was very abrupt after a prolonged still-stand, evicting the Huna Tlingit from their Glacier Bay homeland. ?? 2009 SAGE Publications.

  5. MrBayes tgMC³: a tight GPU implementation of MrBayes.

    Directory of Open Access Journals (Sweden)

    Cheng Ling

    Full Text Available MrBayes is model-based phylogenetic inference tool using Bayesian statistics. However, model-based assessment of phylogenetic trees adds to the computational burden of tree-searching, and so poses significant computational challenges. Graphics Processing Units (GPUs have been proposed as high performance, low cost acceleration platforms and several parallelized versions of the Metropolis Coupled Markov Chain Mote Carlo (MC(3 algorithm in MrBayes have been presented that can run on GPUs. However, some bottlenecks decrease the efficiency of these implementations. To address these bottlenecks, we propose a tight GPU MC(3 (tgMC(3 algorithm. tgMC(3 implements a different architecture from the one-to-one acceleration architecture employed in previously proposed methods. It merges multiply discrete GPU kernels according to the data dependency and hence decreases the number of kernels launched and the complexity of data transfer. We implemented tgMC(3 and made performance comparisons with an earlier proposed algorithm, nMC(3, and also with MrBayes MC(3 under serial and multiply concurrent CPU processes. All of the methods were benchmarked on the same computing node from DEGIMA. Experiments indicate that the tgMC(3 method outstrips nMC(3 (v1.0 with speedup factors from 2.1 to 2.7×. In addition, tgMC(3 outperforms the serial MrBayes MC(3 by a factor of 6 to 30× when using a single GTX480 card, whereas a speedup factor of around 51× can be achieved by using two GTX 480 cards on relatively long sequences. Moreover, tgMC(3 was compared with MrBayes accelerated by BEAGLE, and achieved speedup factors from 3.7 to 5.7×. The reported performance improvement of tgMC(3 is significant and appears to scale well with increasing dataset sizes. In addition, the strategy proposed in tgMC(3 could benefit the acceleration of other Bayesian-based phylogenetic analysis methods using GPUs.

  6. Modeling the hydrodynamic responses to land reclamation in different regions of a semi-enclosed bay

    Science.gov (United States)

    Yang, Y.; Chui, T. F. M.

    2016-12-01

    Water area in bays has been reclaimed to meet the increasing land demand for development. Numbers of studies have examined the hydrodynamic impacts induced by land reclamations in semi-enclosed bays such as San Francisco Bay in the U.S., Tokyo Bay in Japan, and Jiaozhou Bay in China. However, they have not compared the impacts of land reclamations taken place in different regions. The Deep Bay in China was selected as a case study to evaluate and compare the hydrodynamic responses to land reclamations that narrows the bay mouth and that causes water surface loss inside of the bay. A numerical model was employed to simulate the hydrodynamics throughout the bay and to examine the differences in impacts through scenario experiments. The model was validated using the observations of water elevation, currents, and salinity. To indicate the changes in hydrodynamics, tidal prism, current field, tidal energy flux, and water age were computed. Simulation results show that narrowing the bay mouth length by 30% with ??% loss of its original water surface area would increase the total energy flux entering the bay by 26 %, while 14% loss of its original water surface area in middle bay would decrease the total energy entering the bay by 23%. The two regions of reclamations have both resulted in substantial but different changes in current field, the spatial distribution of tidal energy flux and water age. For example, the reclamation at bay mouth has increased the current velocity and tidal energy flux at the bay mouth while that inside of the bay has streamlined the current field and increased the velocity in the inner bay. The water age throughout the bay has been reduced by 5.1% and 13.7% respectively in the two scenarios, increasing the water exchange ability of the bay with the adjacent sea. This study is beneficial to other semi-enclosed bays considering land reclamations, facilitating quick and preliminary estimations of hydrodynamic impacts for planning and management.

  7. Hydrodynamic and transport responses to land reclamation in different areas of semi-enclosed subtropical bay

    Science.gov (United States)

    Yang, Ye; Chui, Ting Fong May

    2017-07-01

    Many coastal areas worldwide have been reclaimed to meet the increasing land demand. Understanding the effects of land reclamation on the hydrodynamics and transport processes of a semi-enclosed bay is therefore of significance. From a case study of Deep Bay (DB) in China and referring to idealized bay models, the effects of two types of land reclamation, one that narrows the bay mouth and another that reduces the water area inside the bay, were examined in this study. Simulation results of idealized models show that the current velocity at the bay mouth and the incoming tidal energy flux are negatively correlated with the width of bay mouth, as the tidal prism remains almost constant when the bay mouth width reduces. The bay mouth width reduction would also increase the tidal energy dissipation inside of the bay due to friction increase. In DB, a 30% reduction in the mouth width increased the bay mouth current velocity by up to 5% and the total incoming energy flux by 18%. The narrowed bay mouth also substantially changed the bay's vertical structure of salinity, increasing the stratification strength by 1.7×10-4 s-2. For reductions in the water surface area in the head of the bay, results from idealized bay simulations show that the current velocity throughout the bay, the incoming tidal energy flux, and salinity at the inner bay all decrease with water area reduction. Reclaiming 14% of area in DB, the current velocity reduced by 9% at the bay mouth, but increased in the middle and inner parts. The incoming tidal energy flux also increased as the coastline became more streamlined after reclamation, and the salinity at inner bay decreased. Both reclamation types have substantially altered the water and salt transport processes and increased the water exchange ability of the bay with the adjacent sea.

  8. San Diego Bay National Wildlife Refuge: Sweetwater Marsh and South San Diego Bay Units: Comprehensive Conservation Plan and Environmental Impact Statement: Volume I

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on San Diego Bay NWR (Sweetwater Marsh and South San Diego Bay Units) for the next 15...

  9. Aerial reconnaissance of emperor geese and associated waterbirds on the Bristol Bay coastal fringe, Northern Alaska Peninsula, between Kvichak Bay and Port Moller, 25 April 1986

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A aerial reconnaissance was conducted along the Bristol Bay coast of the northern Alaska Peninsula, between Kvichak Bay and Port Moller on 25 April 1986, prior to...

  10. Narrative report : Back Bay National Wildlife Refuge : Calendar year 1976

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Back Bay National Wildlife Refuge outlines Refuge accomplishments during the 1976 calendar year. The report begins with an introduction to...

  11. San Pablo Bay National Wildlife Refuge Climate Adaptation Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Future climate change is expected to cause dramatic changes in the physical and biological environment of the San Pablo Bay National Wildlife Refuge (Refuge). To...

  12. 33 CFR 110.145 - Narragansett Bay, R.I.

    Science.gov (United States)

    2010-07-01

    ... mooring piles or stakes will not be allowed. (ii) Anchorage X-1, Naval explosives and ammunition handling anchorage. The waters of Narragansett Bay northeasterly of Gould Island within a circle having a radius of...

  13. Millimeter-wave Imaging Radiometer Brightness Temperatures, Wakasa Bay, Japan

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes calibrated brightness temperatures measured over Wakasa Bay in the Sea of Japan in January and February 2003. The MIR was carried on a...

  14. Bayes' theorem: A paradigm research tool in biomedical sciences

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-29

    Dec 29, 2008 ... 1Department of Industrial Mathematics and Applied Statistics, Ebonyi State University, Abakaliki, Nigeria. ... Bayes' theorem in biomedical research using examples. ..... educate prospective mothers aged 20 years or less. The.

  15. Back Bay National Wildlife Refuge: Fur Management Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Back Bay National Wildlife Refuge Fur Management Plan directs the management and regulation of trapping. The furbearer management program directly supports the...

  16. 2013 East Bay Seismic Experiment (EBSE) -- Implosion Data, Hayward, Calif

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In August 2013, the California State University, East Bay (CSUEB) in Hayward, California imploded a 13-story building (Warren Hall) that was deemed unsafe because of...

  17. Faults--Drakes Bay and Vicinity Map Area, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data of faults for the geologic and geomorphologic map of the Drakes Bay and Vicinity map area, California. The vector data file is...

  18. San Pablo Bay National Wildlife Refuge: Final Comprehensive Conservation Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on San Pablo Bay NWR for the next 15 years. This plan outlines the Refuge vision and...

  19. Searching for θ13 at Daya Bay

    Energy Technology Data Exchange (ETDEWEB)

    Giedt, Joel [Rensselaer Polytechnic Inst., Troy, NY (United States); Napolitano, James [Temple Univ., Philadelphia, PA (United States)

    2015-06-08

    An experiment has been carried out by the Daya Bay Collaboration to measure the neutrino mixing angle θ13. In addition, the grant has supported research into lattice field theory beyond the standard model.

  20. Circulation and geostrophic transport in the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, D.P.; Murty, V.S.N.

    Utilising the hydrographic data collected during the early northeast monsoon of 1983 and southwest monsoon of 1984, the circulation of waters of the Bay of Bengal and the associated volume transport have been studied in the upper 1000 m...

  1. Salt balance and mixing in the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Varkey, M.J.

    Basic fields of temperature salinity, density and currents in the Bay of Bengal are investigated using data archieved at the National Oceanographic Data Centre (NODC) Washington, D.C. and the Indian National Oceanographic Data Centre (INODC...

  2. Surface layer temperature inversion in the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Pankajakshan, T.; Gopalakrishna, V.V.; Muraleedharan, P.M.; Reddy, G.V.; Araligidad, N.; Shenoy, Shrikant

    of Bengal, such as occurrence time, characteristics, stability, inter-annual variability and generating mechanisms. Spatially organized temperature inversion occurs in the coastal waters of the western and northeastern Bay during winter (November...

  3. Delaware Bay, Delaware Sediment Distribution 2003 to 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The area of coverage consists of 38 square miles of benthic habitat mapped from 2003 to 2004 along the middle to lower Delaware Bay Coast. The bottom sediment map...

  4. Microplastic contamination in the San Francisco Bay, California, USA.

    Science.gov (United States)

    Sutton, Rebecca; Mason, Sherri A; Stanek, Shavonne K; Willis-Norton, Ellen; Wren, Ian F; Box, Carolynn

    2016-08-15

    Despite widespread detection of microplastic pollution in marine environments, data describing microplastic abundance in urban estuaries and microplastic discharge via treated municipal wastewater are limited. This study presents information on abundance, distribution, and composition of microplastic at nine sites in San Francisco Bay, California, USA. Also presented are characterizations of microplastic in final effluent from eight wastewater treatment plants, employing varying treatment technologies, that discharge to the Bay. With an average microplastic abundance of 700,000particles/km(2), Bay surface water appears to have higher microplastic levels than other urban waterbodies sampled in North America. Moreover, treated wastewater from facilities that discharge into the Bay contains considerable microplastic contamination. Facilities employing tertiary filtration did not show lower levels of contamination than those using secondary treatment. As textile-derived fibers were more abundant in wastewater, higher levels of fragments in surface water suggest additional pathways of microplastic pollution, such as stormwater runoff. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Isopachs--Salt Point to Drakes Bay, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the sediment-thickness map of the Salt Point to Drakes Bay, California, region. The raster data file is included in...

  6. Macrofouling community structure in Kanayama Bay, Kii Peninsula (Japan)

    Digital Repository Service at National Institute of Oceanography (India)

    Raveendran, T.V.; Harada, E.

    An investigation on the macrofouling community in Kanayama Bay, Kill Peninsula, Japan was undertaken from June 1994 to May 1995 by exposing fiber reinforced plastic (FRP) panels at subsurface and bottom (2.2 m) depths. The composition and abundance...

  7. EnviroAtlas - Green Bay, WI - Atlas Area Boundary

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset shows the boundary of the Green Bay, WI Atlas Area. It represents the outside edge of all the block groups included in the EnviroAtlas Area....

  8. Nestucca Bay National Wildlife Refuge: Comprehensive Conservation Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on Nestucca Bay National Wildlife Refuge for the next 15 years. This plan outlines the...

  9. AMMR Air and Brightness Temperature Data, Wakasa Bay

    Data.gov (United States)

    National Aeronautics and Space Administration — The Wakasa Bay Field Campaign was conducted in January and February 2003 to validate rainfall algorithms developed for the Advanced Microwave Scanning Radiometer -...

  10. Backscatter A [8101]--Drakes Bay and Vicinity, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of Drakes bay and Vicinity map area, California. Backscatter data are provided as separate grids...

  11. Backscatter A [8101]--Offshore Half Moon Bay, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Half Moon Bay map area, California. Backscatter data are provided as two...

  12. Backscatter C [7125]--Drakes Bay and Vicinity, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of Drakes bay and Vicinity map area, California. Backscatter data are provided as separate grids...

  13. Backscatter B [7125]--Offshore Half Moon Bay, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Half Moon Bay map area, California. Backscatter data are provided as two...

  14. San Francisco Bay Interferometric Side Scan Imagery: Area B

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — High resolution sonar data were collected over ultra-shallow areas of the San Francisco Bay estuary system. Bathymetric and acoustic backscatter data were collected...

  15. Grand Bay National Wildlife Refuge: Comprehensive Conservation Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on Grand Bay NWR for the next 15 years. This plan outlines the Refuge vision and purpose...

  16. Possible effects of Bay fill on air quality

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Baylands Subcommittee is seeking background information on the effects and ramifications of developing those parts of San Francisco Bay that lie in Santa Clara...

  17. 2002 NOAA Lidar: Willapa Bay, WA Mudflat (WA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA contracted with Spencer B. Gross, Inc. (SBG) to obtain airborne Lidar of Willapa Bay, Washington during low tide conditions. The Lidar data was processed to...

  18. Data supporting study of Ecosystem Metabolism in Pensacola Bay estuary

    Data.gov (United States)

    U.S. Environmental Protection Agency — These files house the data collected during 2013 in lower Pensacola Bay. The data were used to estimate aquatic primary production and respiration. This dataset is...

  19. Environmental Contaminants Evaluation of St. Andrew Bay, Florida: Volume 1

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Between 1985 and 1997, a general survey of St. Andrew Bay, Florida, was conducted to measure chemical contaminant concentrations in the sediments and selected biota....

  20. Southern Monterey Bay Littoral Cell CRSMP Proposed Receiver Site 2008

    Data.gov (United States)

    California Department of Resources — Given the location of the critical areas of erosion and the need to avoid adverse impacts to local sensitive habitat, the Southern Monterey Bay Coastal RSM Plan...

  1. Physical oceanography of the Bay of Bengal and Andaman Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Varkey, M.J.; Murty, V.S.N.; Suryanarayana, A.

    Physical oceanography of the Bay of Bengal and Andaman Sea is reviewed for the first time. All available information for over 50 years is consolidated in this review. To begin with, information on peripheral or related aspects of climate...

  2. Tampa Bay Topographic/Bathymetric Digital Elevation Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In this joint demonstration project for the Tampa Bay region, NOAA's National Ocean Service (NOS) and the U.S. Geological Survey (USGS) have merged NOAA bathymetric...

  3. Annual Narrative Oyster Bay National Wildlife Refuge 1972

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Oyster Bay National Wildlife Refuge outlines Refuge accomplishments during the 1972 calendar year. The report begins by summarizing...

  4. APR-2 Dual-frequency Airborne Radar Observations, Wakasa Bay

    Data.gov (United States)

    National Aeronautics and Space Administration — In January and February 2003, the Airborne Second Generation Precipitation Radar (APR-2) collected data in the Wakasa Bay AMSR-E validation campaign over the sea of...

  5. Species List for Back Bay National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a species list of fish, mammals, amphibians, and reptiles that are either common to the Back Bay area or have ranges that extend into this region. This list...

  6. San Francisco Bay, California 1 arc-second DEM

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 1-second San Francisco Bay, California Elevation Grid provides bathymetric data in ASCII raster format of 1-second resolution in geographic coordinates. This...

  7. Bristol Bay, Alaska Subarea ESI: NESTS (Nest Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for nesting seabirds (alcids, pelagic birds), gulls, terns, diving birds, and raptors in the Bristol Bay...

  8. Bristol Bay, Alaska Subarea ESI: INVERT (Invertebrate Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine and estuarine invertebrate species in the Bristol Bay Subarea. The Subarea includes marine and...

  9. Bristol Bay, Alaska Subarea ESI: MGT (Management Area Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive human-use data for Critical Habitats, Wildlife Refuges, National Park lands, and other management areas in the Bristol Bay Subarea....

  10. Bristol Bay, Alaska Subarea ESI: FISHL (Fish Lines)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for anadromous fish species in the Bristol Bay Subarea. The Subarea includes marine and coastal areas of...

  11. Bristol Bay, Alaska Subarea ESI: HABITATS (Habitats Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for submerged aquatic vegetation (SAV) in the Bristol Bay Subarea. The Subarea includes marine and coastal...

  12. 2004 Saginaw Bay, Lake Huron, Michigan Coastline LiDAR

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This metadata document describes the collection and processing of Light Detection and Ranging (LIDAR) data over an area along the coast of Saginaw Bay, Lake Huron,...

  13. The Voisey's Bay mine/mill project: project description report

    National Research Council Canada - National Science Library

    1996-01-01

    ...). The project referred to is the proposed development of a nickel-copper-cobalt mine and mill complex, including associated infrastructure, in the area of the Voisey's Bay discovery on the north coast of Labrador...

  14. Nekton-habitat associations in Yaquina Bay, Oregon - March 2008

    Science.gov (United States)

    We conducted a 3-year field study to determine the relative nekton usage of 4 intertidal habitats (eelgrass [Zostera marina], mud shrimp [Upogebia pugettensis], ghost shrimp [Neotrypaea californiensis], and unvegetated sand) in Yaquina Bay, Oregon. Nekton samples were collected u...

  15. National Status and Trends: Bioeffects Program - San Francisco Bay Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study was based on the sediment quality triad (SQT) approach. A stratified probabilistic sampling design was utilized to characterize the San Francisco Bay...

  16. National Status and Trends: Bioeffects Program - Kachemak Bay Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study was based on the sediment quality triad (SQT) approach. A stratified probabilistic sampling design was utilized to characterize the Kachemak Bay system in...

  17. Primary production in the Bay of Bengal during August 1977

    Digital Repository Service at National Institute of Oceanography (India)

    Devassy, V.P.; Bhattathiri, P.M.A.; Radhakrishna, K.

    Primary production, chlorophyll @ia@@, phaeophytin, phytoplankton and particulate organic carbon (POC) were studied at 14 stations in the Bay of Bengal during August 1977. Column primary production, chlorophyll @ia@@, and phaeopigments varied from 0...

  18. Birds and mammals recorded at Ugashik Bay and Cinder River

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — From 26 September through 19 October 1985, biologists with the Division of Research, U. S. Fish and Wildlife Service, were present at Ugashik Bay, along the NE side...

  19. Folds--Offshore of Half Moon Bay Map Area, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for folds for the geologic and geomorphic map of the Offshore of Half Moon Bay map area, California. The vector data file is...

  20. Field guide to fishes of the chesapeake bay

    CERN Document Server

    Murdy, Edward O.

    2013-01-01

    The only comprehensive field guide to the Chesapeake’s fishes, this book is an indispensable resource for both anglers and students of the Bay. Vivid illustrations by Val Kells complement the expertise of researchers Edward O. Murdy and John A. Musick. They describe fishes that inhabit waters ranging from low-salinity estuaries to the point where the Bay meets the Atlantic Ocean. Key features of this field guide include• full-color illustrations of more than 200 species• text that is presented adjacent to illustrations for easy reference• detailed descriptions of physical characteristics, range, occurrence in the Bay, reproduction, diet, and statistics from fisheries research• spot illustrations that highlight critical features of certain fish• illustrations of juveniles when they look different from adults• appendices that include identification keys Formatted as a compact field guide for students, scientists, researchers, and fishermen, Field Guide to Fishes of the Chesapeake Bay should be a ...

  1. Faults--Offshore of Half Moon Bay Map Area, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for faults for the geologic and geomorphic map of the Offshore of Half Moon Bay map area, California. The vector data file is...

  2. Environmental Assessment: Impoundment Rehabilitation on Back Bay National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The U.S. Fish and Wildlife Service proposes to rehabilitate the wetland impoundments of Back Bay National Wildlife Refuge. The environmental assessment describes the...

  3. Distribution of nutrients in the western Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    DeSousa, S.N.; Naqvi, S.W.A.; Reddy, C.V.G.

    Distribution of phosphates and nitrates in relation to some physico-chemical features of the western Bay of Bengal during August-September 1976 indicated marked regional variations. The mixed surface layer which was associated with high oxygen...

  4. Characteristics of nearshore waters in Binge Bay, Karwar

    Digital Repository Service at National Institute of Oceanography (India)

    Zingde, M.D.; Singbal, S.Y.S.

    Environmental parameters to delineate characteristics of nearshore waters were studied over one year in Binge Bay. Existence of low temperature, high saline, low dissolved oxygen and high nutrient water during August-October at the bottom...

  5. Vehicular regulations announced for Back Bay National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is an announcement pertaining to regulations published in the Federal Register concerning the Back Bay National Wildlife Refuge. The regulations all...

  6. Neah Bay, Washington Tsunami Forecast Grids for MOST Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Neah Bay, Washington Forecast Model Grids provides bathymetric data strictly for tsunami inundation modeling with the Method of Splitting Tsunami (MOST) model....

  7. Bristol Bay, Alaska Subarea ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for shorebirds, waterfowl, raptors, diving birds, and seabirds in the Bristol Bay Subarea. The Subarea...

  8. Shallow-water Benthic Habitats in Jobos Bay

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Shallow-water (<30m) benthic habitat maps of the nearshore marine environment of Jobos Bay, Puerto Rico were mapped and characterized using visual interpretation...

  9. Narrative report : Back Bay National Wildlife Refuge : Calendar year 1971

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Back Bay NWR outlines Refuge accomplishments during the 1971 calendar year. The report begins by summarizing the weather conditions,...

  10. Narrative report : Back Bay National Wildlife Refuge : Calendar year 1970

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Back Bay NWR outlines Refuge accomplishments during the 1970 calendar year. The report begins by summarizing the weather conditions,...

  11. Bristol Bay, Alaska Subarea ESI: FISH (Fish Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, anadromous, and freshwater fish species in the Bristol Bay Subarea. The Subarea...

  12. Folds--Drakes Bay and Vicinity Map Area, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data of folds for the geologic and geomorphologic map of the Drakes Bay and Vicinity map area, California. The vector data file is...

  13. Distribution of particulate carbohydrate species in the Bay of Bengal

    Indian Academy of Sciences (India)

    ; particulate carbohydrates; particulate uronic acids; organic matter, Bay of Bengal. ... Council of Scientific and Industrial Research, Marine Corrosion and Material Research Division, National Institute of Oceanography, Dona Paula 403 004, ...

  14. South Bay Salt Ponds Restoration Project : Final Data Acquisition Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document provides the Data Acquisition Plan for the South Bay Salt Pond Restoration Project. The purpose of the Data Acquisition Plan is to guide the collection...

  15. Back Bay National Wildlife Refuge Croplands Management Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Back Bay National Wildlife Refuge Cropland Management Plan focuses on the production of supplemental grain and browse foods to maintain wildlife populations at...

  16. Marsh and Water Management Plan: Back Bay National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Back Bay National Wildlife Refuge Marsh and Water Management Plan has been developed to meet the station objectives set forth in the Master Plan. The purpose of...

  17. DDT residues in sediments from the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.; SenGupta, R.

    in the sediments from the Bay of Bengal. Peterson grab and hydrographic winch was used to collect the sediment samples. Each sample was extracted and cleaned. Residues were detected by electron capture gas chromatography. A range variation in the concentration...

  18. Southern Monterey Bay Littoral Cell CRSMP Sensitive Habitat 2008

    Data.gov (United States)

    California Department of Resources — One of the most important functions of the southern Monterey Bay coastal system is its role as a habitat for a unique flora and fauna. The beaches are habitat for...

  19. Summer distribution of pelagic birds in Bristol Bay, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Bristol Bay and its islands, the embayments, lagoons, and other estuaries along the north side of the Alaska Peninsula, and the nesting cliffs on the north shore,...

  20. Monosaccharide composition of suspended particles from the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosle, N.B.; Sankaran, P.D.; Wagh, A.B.

    Neutral carbohydrates were determined as alditol acetates by capillary gas chromatography in the hydrolysates of suspended particulate samples (40) collected from 8 depths (approx 1 to 1,000 m) at 5 stations of the Bay of Bengal. Eight individual...

  1. Seafloor character--Offshore of Half Moon Bay, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents the seafloor-character map of the Offshore of Half Moon Bay map area, California. The raster data file is included in...

  2. Narrative Report : San Francisco Bay NWR Complex : Fiscal Year 1974

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report details the conditions and management of San Francisco Bay National Wildlife Refuge in 1974. The report begins with a general...

  3. Quarterly refuge narrative report : Cold Bay Game Management [1949

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Cold Bay Game Management outlines Refuge accomplishments from January through April of 1949. The report begins by summarizing the weather...

  4. Recent Results from the Daya Bay Neutrino Experiment

    CERN Document Server

    Tang, Wei

    2015-01-01

    The Daya Bay neutrino experiment has recently updated the oscillation analysis results with 621 days of data in 2015, which has 3.6 times more statistics than the previous publication in 2014. The relative $\\bar{\

  5. AFSC/ABL: Auke Bay Climatology 1959-2013

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data set includes available climatological and related physical environmental records for Auke Bay, Auke Creek and Auke Lake beginning in 1959. Daily high and low...

  6. Migratory Bird Disease Contingency Plan: Back Bay National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Back Bay National Wildlife Refuge was established in 1938 to provide habitat and protection for migratory birds. Management objectives have since been expanded to...

  7. Massachusetts Bay - Internal wave packets digitized from SAR imagery

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This feature class contains internal wave packets digitized from SAR imagery at 1:350,000 scale in Massachusetts Bay. Internal waves are nonsinusoidal waves that...

  8. Eureka Littoral Cell CRSMP Humboldt Bay Shoreline Types 2011

    Data.gov (United States)

    California Department of Resources — In 2011 Aldaron Laird walked and kayaked the entire shoreline of Humboldt Bay mapping the shoreline conditions onto 11x17 laminated fieldmaps at a scale of 1' = 200'...

  9. Island Bay Wilderness Character Monitoring Back-end Database

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is the back-end data file for the Island Bay Wilderness Character Monitoring Application. User interface and lookup databases are required for use (see...

  10. Vertical distribution of planktonic copepods in Tokyo Bay in summer

    National Research Council Canada - National Science Library

    Itoh, Hiroshi; Tachibana, Aiko; Nomura, Hideaki; Tanaka, Yuji; Furota, Toshio; Ishimaru, Takashi

    2011-01-01

    ... in the inner part of Tokyo Bay, central Japan. Acartia sinjiensis showed a peak of the population density in the surface water, which was influenced by river discharge, and Paracalanus parvus s.l...

  11. Evaluation of Contaminant Residues in Delaware Bay Bald Eagle Nestlings

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Bald eagle (Naliacetus leucocephalus) nesting attempts have steadily increased over the past decade in the Delaware Bay and River drainage basin; however, nesting...

  12. Long-term morphologic evolution of the Hangzhou Bay, China

    Science.gov (United States)

    Wen, W.; Zhijun, D.; Hualiang, X.

    2013-12-01

    Estuaries are the most productive ecosystems of coastal zones in the world, which are significant to mankind as places of navigation, recreation and commerce as well as extensive and diverse habitats for wildlife. However, most estuary environments in the world had occurred greatly changes in recent decades. These estuaries have suffered from impacts of forcing factors including wave climate, mean sea level change and storm surge, especial to the intensive human activities such as training wall construction, channel dredging, sand mining and dam constructions. Thus, there have been increasing concerns about estuary environment changes under effects of different factors. Riverine loads into the Changjiang Estuary have declined dramatically with the construction of Three Gorges Dam (TGD) in 2003. The morphological evolution of the Hangzhou bay that located the southern proximity of the Yangtze estuary starts to attract increasing attentions due to most material of the Hangzhou bay received from Yangtze estuary. In this paper, historical bathymetric charts were digitized and analyzed within a GIS to provide quantitative estimate of changes in volumes in different regions below 0 m elevation. The results show that Hangzhou bay has experienced a major loss in estuarine volume of about 15% with annual mean sediment deposition rate of 80 million m3/a during the last 75 years. However, there is a large-scale spatial adjustment in Hangzhou bay: Bathymetric changes of the Hangzhou bay can be rapidly shifted within the range of 8-10 classes. Volume of the Jinshanzui upstream of the Hangzhou bay has obviously decreased in the last 75 years, especially during 2003-2008. However, Volume of the southern Hangzhou bay has experienced slowly decrease with minor deposition. The northern Hangzhou bay had largely volume changes with rapidly decrease during 1931-1981, and drastically increase since 2003. Further analysis of the bathymetric data relating to possible factors indicates

  13. Bayes' theorem: A paradigm research tool in biomedical sciences

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-29

    Dec 29, 2008 ... P B P E B P C P E C. = +. (4). For computing P(B/E) and P(C/E) using Bayes' rule denominator would be exactly the same as above, the numerator would be P(B) P(E/B) and P(C) P(E/C), respectively. A proof and more formal development of. Bayes' rule can be found in most probability texts. (Rosner, 1990).

  14. An Oceanographic and Climatological Atlas of Bristol Bay

    Science.gov (United States)

    1987-10-01

    have a profound the bay North Pacific water which has just entered effect on regional oceanographic phenomena. An the Bering Sea through Unimak Pass... Unimak circulation in outer Bristol Bay consists of a Island, much of the coastal current is entrained typically unclosed counterclockwise gyre open to...Peninsula and become more face currents. cyclonic and rotary offshore. National Ocean Sea level changes on either side of Unimak Survey current tables

  15. Environmental and sanitary conditions of Guanabara Bay, Rio de Janeiro

    Directory of Open Access Journals (Sweden)

    Giovana De Oliveira Fistarol

    2015-11-01

    Full Text Available Guanabara Bay is the second largest bay in the coast of Brazil, with an area of 384 km2. In its surroundings live circa 16 million inhabitants, out of which 6 million live in Rio de Janeiro city, one of the largest cities of the country, and the host of the 2016 Olympic Games. Anthropogenic interference in Guanabara Bay area started early in the XVI century, but environmental impacts escalated from 1930, when this region underwent an industrialization process. Herein we present an overview of the current environmental and sanitary conditions of Guanabara Bay, a consequence of all these decades of impacts. We will focus on microbial communities, how they may affect higher trophic levels of the aquatic community and also human health. The anthropogenic impacts in the bay are flagged by heavy eutrophication and by the emergence of pathogenic microorganisms that are either carried by domestic and/or hospital waste (e.g. virus, KPC-producing bacteria, and fecal coliforms, or that proliferate in such conditions (e.g. vibrios. Antibiotic resistance genes are commonly found in metagenomes of Guanabara Bay planktonic microorganisms. Furthermore, eutrophication results in recurrent algal blooms, with signs of a shift towards flagellated, mixotrophic groups, including several potentially harmful species. A recent large-scale fish kill episode, and a long trend decrease in fish stocks also reflects the bay’s degraded water quality. Although pollution of Guanabara Bay is not a recent problem, the hosting of the 2016 Olympic Games propelled the government to launch a series plans to restore the bay’s water quality. If all plans are fully implemented, the restoration of Guanabara Bay and its shores may be one of the best legacies of the Olympic Games in Rio de Janeiro.

  16. PENERAPAN NAIVE BAYES PADA INTRUSION DETECTION SYSTEM DENGAN DISKRITISASI VARIABEL

    Directory of Open Access Journals (Sweden)

    I Nyoman Trisna Wirawan

    2015-07-01

    Pada penelitian ini akan dibahas mengenai penerapan naive bayes classifier dengan menggunakan pemilihan atribut berdasarkan pada korelasi serta preprocessing data dengan diskritisasi dengan menggunakan metode mean/standar deviasi untuk atribut kontinu dengan menggunakan 3-interval dan 5-interval. Hasil percobaan menunjukan bahwa penerapan naive bayes pada klasifikasi data yang telah melewati proses diskritisasi mampu memberikan akurasi hingga 89% dengan running time rata-rata adalah 31 detik.

  17. Potential climate-change impacts on the Chesapeake Bay

    Science.gov (United States)

    Najjar, R.; Pyke, C.; Adams, M.; Breitburg, D.; Hershner, C.; Kemp, M.; Howarth, R.; Mulholland, M.; Paolisso, M.; Secor, D.; Sellner, K.; Wardrop, D.; Wood, R.

    2008-12-01

    We review current understanding of the potential impact of climate change on the Chesapeake Bay. Scenarios for carbon dioxide emissions indicate that by the end of the 21st century the Bay region will experience significant changes in climate forcings with respect to historic conditions, including increases in carbon dioxide concentrations, sea level, and water temperature of 50-160 percent, 0.7-1.6 m, and 2-6 K, respectively. Also likely are increases in precipitation amount (particularly in the winter and spring), precipitation intensity, intensity of tropical and extratropical cyclones (though their frequency may decrease), and sea-level variability. The greatest uncertainty is associated with changes in annual streamflow, though it is likely that winter and spring flows will increase. Climate change alone will cause the Bay to function very differently in the future. Likely changes include: (1) an increase in coastal flooding and submergence of estuarine wetlands; (2) an increase in salinity variability on many time scales; (3) an increase in harmful algae; (4) an increase in hypoxia; (5) a reduction of eelgrass, the dominant submerged aquatic vegetation in the Bay; and (6) altered interactions among trophic levels, with warm-water fish and shellfish species ultimately being favored in the Bay. The magnitude of these changes is sensitive to the carbon dioxide emission trajectory, so that actions taken now to reduce carbon dioxide emissions will reduce climate impacts on the Bay. Research needs include improved precipitation and streamflow projections for the Bay watershed and whole-system monitoring and modeling (supplemented by process studies) that can capture the likely non-linear responses of the Chesapeake Bay system to climate variability and change.

  18. Unscaled Bayes factors for multiple hypothesis testing in microarray experiments.

    Science.gov (United States)

    Bertolino, Francesco; Cabras, Stefano; Castellanos, Maria Eugenia; Racugno, Walter

    2015-12-01

    Multiple hypothesis testing collects a series of techniques usually based on p-values as a summary of the available evidence from many statistical tests. In hypothesis testing, under a Bayesian perspective, the evidence for a specified hypothesis against an alternative, conditionally on data, is given by the Bayes factor. In this study, we approach multiple hypothesis testing based on both Bayes factors and p-values, regarding multiple hypothesis testing as a multiple model selection problem. To obtain the Bayes factors we assume default priors that are typically improper. In this case, the Bayes factor is usually undetermined due to the ratio of prior pseudo-constants. We show that ignoring prior pseudo-constants leads to unscaled Bayes factor which do not invalidate the inferential procedure in multiple hypothesis testing, because they are used within a comparative scheme. In fact, using partial information from the p-values, we are able to approximate the sampling null distribution of the unscaled Bayes factor and use it within Efron's multiple testing procedure. The simulation study suggests that under normal sampling model and even with small sample sizes, our approach provides false positive and false negative proportions that are less than other common multiple hypothesis testing approaches based only on p-values. The proposed procedure is illustrated in two simulation studies, and the advantages of its use are showed in the analysis of two microarray experiments. © The Author(s) 2011.

  19. 76 FR 31851 - Safety Zone; Put-in-Bay Fireworks, Fox's the Dock Pier; South Bass Island, Put-in-Bay, OH

    Science.gov (United States)

    2011-06-02

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Put-in-Bay Fireworks, Fox's the Dock Pier...-0417 Safety Zone; Put-In-Bay Fireworks, Fox's the Dock Pier, South Bass Island; Put-In-Bay, OH. (a...

  20. San Francisco Bay Area Baseline Trash Loading Summary Results, San Francisco Bay Area CA, 2012, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — The San Francisco Bay Area stormwater permit sets trash control guidelines for discharges through the storm drain system. The permit covers Alameda, Contra Costa,...

  1. 78 FR 27126 - East Bay, St. Andrews Bay and the Gulf of Mexico at Tyndall Air Force Base, Florida; Restricted...

    Science.gov (United States)

    2013-05-09

    ... Gulf of Mexico and Apalachicola Bay south of Apalachicola, Fla., Drone Recovery Area, Tyndall Air Force... approximations obtained using a commercial mapping program which utilizes Simple Cylindrical projection with a...

  2. One big rig, two valuable functions

    Energy Technology Data Exchange (ETDEWEB)

    Anon

    2004-11-01

    A hybrid coil tubing and conventional workover rig, tailor-made for conditions on Alaska's remote North Slope is described. The dual function rig, owned by BP Exploration, towers 142 feet above the barren Arctic tundra, and weighs between 1.5 and 2 million pounds, rests on eight enormous wheels that stand 11.5 feet tall and 3.5 feet wide, and is supported by 64 smaller tires in between. The rig includes the hybrid coiled tubing rig and a conventional workover rig; it exerts less than 100 pounds per square inch of pressure on the tender Arctic surface as it moves forward at a top speed of two miles per hour. It is considered by its developers as the next-step change in providing cost-effective access to reserves in the large, mature and remote oilfields such as those of Alaska's Prudhoe Bay. The rig is the product of cooperation between Schlumberger expertise in coiled tubing drilling and Nordic-Calista's know-how of jointed pipe operations and operating rigs in an Arctic environment. It is the first time in Prudhoe Bay, and probably in the world, that a coiled tubing unit was installed on a rig to do coiled-tubing sidetracks, i.e to drill a secondary wellbore away from the original wellbore. Since the first unit was commissioned in 1996, the rig has drilled 280 wells. Rig No. 2, much improved and commissioned in 2002, drilled about 30 wells to date. Unlike Rig No, 1, Rig No. 2 can change reels without a crane, and it has a hydraulic pipe skate that moves jointed pipe to and from the rig floor without human aid. The expectation is that using this rig it will be possible to do micro-hole exploration drilling on the North Slope (i.e. drilling a small surface hole with jointed pipe and then switch to coiled tubing), substantially cutting the cost of exploration.

  3. Soundscape Ecology of Hawaiian Spinner Dolphin Resting Bays

    Science.gov (United States)

    Heenehan, Heather Leigh

    Sound is a key sensory modality for Hawaiian spinner dolphins. Like many other marine animals, these dolphins rely on sound and their acoustic environment for many aspects of their daily lives, making it is essential to understand soundscape in areas that are critical to their survival. Hawaiian spinner dolphins rest during the day in shallow coastal areas and forage offshore at night. In my dissertation I focus on the soundscape of the bays where Hawaiian spinner dolphins rest taking a soundscape ecology approach. I primarily relied on passive acoustic monitoring using four DSG-Ocean acoustic loggers in four Hawaiian spinner dolphin resting bays on the Kona Coast of Hawai'i Island. 30-second recordings were made every four minutes in each of the bays for 20 to 27 months between January 8, 2011 and March 30, 2013. I also utilized concomitant vessel-based visual surveys in the four bays to provide context for these recordings. In my first chapter I used the contributions of the dolphins to the soundscape to monitor presence in the bays and found the degree of presence varied greatly from less than 40% to nearly 90% of days monitored with dolphins present. Having established these bays as important to the animals, in my second chapter I explored the many components of their resting bay soundscape and evaluated the influence of natural and human events on the soundscape. I characterized the overall soundscape in each of the four bays, used the tsunami event of March 2011 to approximate a natural soundscape and identified all loud daytime outliers. Overall, sound levels were consistently louder at night and quieter during the daytime due to the sounds from snapping shrimp. In fact, peak Hawaiian spinner dolphin resting time co-occurs with the quietest part of the day. However, I also found that humans drastically alter this daytime soundscape with sound from offshore aquaculture, vessel sound and military mid-frequency active sonar. During one recorded mid

  4. Recipient Capacity of Tvaeren, a Baltic Bay

    Energy Technology Data Exchange (ETDEWEB)

    Agnedal, P.O.; Bergstroem, S.O.W.

    1966-07-15

    The research station at Studsvik is situated on the Baltic coast and includes several reactors and laboratories, a waste disposal plant serving both the station and waste producers outside Studsvik. A storage plant for irradiated fuel from power reactors has also been built. A total of 850 people are employed. The waste disposal plant was designed for a personnel of 900 using foreign information to correlate waste amounts to personnel. After a delay production has increased at a rate very close to the one expected. The composition of the waste is varied and difficult to predict. Minor amounts of fission products, active corrosion products, and fissile materials have been detected. Most of the waste activity is released to a strait leading into the Bay. Large volumes of water with very low specific activity are released immediately off the coast. Hydrological and dispersion data for the bay are quoted from a paper presented at the symposium mentioned below. The Baltic has brackish water. Both the chemistry and the biology are quite different from those of marine or fresh water recipients. A short description is given of the fauna and flora and important food webs are discussed. The different ways in which man is exposed to radioactivity in waste releases are dependent upon biological accumulation in living organisms and adsorption to dead materials. Fish consumption is the type of exposure which is likely to be the most critical, though it is possible that the exposure from sunbathing and fishing-gear handling could reach similar significance if conservative calculations are used. Accumulation factors from water to fish are given for iron, cobalt,and zinc . Permissible releases have been calculated using relevant accumulation factors. Fission products and corrosion products seem to be of similar significance with regard to possible human exposure. Permission to release liquid waste is granted by water courts in Sweden and operations inspected by special authorities

  5. Chesapeake Bay Study. Supplement A. Problem Identification. Supplement B. Public Involvement. Supplement C. The Chesapeake Bay Hydraulic Model.

    Science.gov (United States)

    1984-09-01

    ORGANISMS Algae Mollusca (Shellfish) Pisces ( Fish ) (Cont.) (Cont.) Blue-Green Alga Northern puffer Diatom (4 general) ** Coot clam Oyster toadfish...Chesapeake Bay Estuary A-10 The Biota of Chesapeake Bay A-15 Aquatic Plants A-15 Fish and Wildlife A- 16 Important Plant and Animal Organisms A-18 Plant and...Erosion Problems A-92 Fish and Wildlife A-92 Electric Power A-97 Power Requirements and Generating Facilities A-97 Market Sectors A-97 Cooling Water

  6. THE RESPONSE OF MONTEREY BAY TO THE 2010 CHILEAN EARTHQUAKE

    Directory of Open Access Journals (Sweden)

    Laurence C. Breaker

    2011-01-01

    Full Text Available The primary frequencies contained in the arrival sequence produced by the tsunami from the Chilean earthquake of 2010 in Monterey Bay were extracted to determine the seiche modes that were produced. Singular Spectrum Analysis (SSA and Ensemble Empirical Mode Decomposition (EEMD were employed to extract the primary frequencies of interest. The wave train from the Chilean tsunami lasted for at least four days due to multipath arrivals that may not have included reflections from outside the bay but most likely did include secondary undulations, and energy trapping in the form of edge waves, inside the bay. The SSA decomposition resolved oscillations with periods of 52-57, 34-35, 26-27, and 21-22 minutes, all frequencies that have been predicted and/or observed in previous studies. The EEMD decomposition detected oscillations with periods of 50-55 and 21-22 minutes. Periods in the range of 50-57 minutes varied due to measurement uncertainties but almost certainly correspond to the first longitudinal mode of oscillation for Monterey Bay, periods of 34-35 minutes correspond to the first transverse mode of oscillation that assumes a nodal line across the entrance of the bay, a period of 26- 27 minutes, although previously observed, may not represent a fundamental oscillation, and a period of 21-22 minutes has been predicted and observed previously. A period of ~37 minutes, close to the period of 34-35 minutes, was generated by the Great Alaskan Earthquake of 1964 in Monterey Bay and most likely represents the same mode of oscillation. The tsunamis associated with the Great Alaskan Earthquake and the Chilean Earthquake both entered Monterey Bay but initially arrived outside the bay from opposite directions. Unlike the Great Alaskan Earthquake, however, which excited only one resonant mode inside the bay, the Chilean Earthquake excited several modes suggesting that the asymmetric shape of the entrance to Monterey Bay was an important factor and that the

  7. Highlights from the Daya Bay Neutrino Experiment

    Directory of Open Access Journals (Sweden)

    Wang Zhe

    2014-04-01

    Full Text Available With an understanding of the energy response of the anti-neutrino detectors, the Daya Bay collaboration presents new results using gadolinium-neutron capture: sin2 2θ13 = 0.108 ± 0.028 and |Δmee2| = 2.55−0.18+0.21 × 10−3 eV2 with only the distortion information of the neutrino energy spectrum shape, and sin2 2θ13 = 0.090−0.009+0.008 and |Δmee2| = 2.59−0.20+0.19 10−3 eV2 with both the shape and event rate information. It is also demonstrated that a clean inverse beta decay sample can be extracted using hydrogen-neutron capture, which is now being used for neutrino oscillation measurement. The supernova online trigger is designed and implemented, which can provide about 100% efficiency for all SN1987A-scale supernova bursts within the Milky Way.

  8. Wastewater effluent dispersal in Southern California Bays

    KAUST Repository

    Uchiyama, Yusuke

    2014-03-01

    The dispersal and dilution of urban wastewater effluents from offshore, subsurface outfalls is simulated with a comprehensive circulation model with downscaling in nested grid configurations for San Pedro and Santa Monica Bays in Southern California during Fall of 2006. The circulation is comprised of mean persistent currents, mesoscale and submesoscale eddies, and tides. Effluent volume inflow rates at Huntington Beach and Hyperion are specified, and both their present outfall locations and alternative nearshore diversion sites are assessed. The effluent tracer concentration fields are highly intermittent mainly due to eddy currents, and their probability distribution functions have long tails of high concentration. The dilution rate is controlled by submesoscale stirring and straining in tracer filaments. The dominant dispersal pattern is alongshore in both directions, approximately along isobaths, over distances of more than 10. km before dilution takes over. The current outfall locations mostly keep the effluent below the surface and away from the shore, as intended, but the nearshore diversions do not. © 2014 Elsevier Ltd.

  9. Nearshore phytoplankton of Hammond Bay, Lake Huron

    Science.gov (United States)

    Brown, Charles L.; Manny, Bruce A.

    1983-01-01

    To predict the effects of increased nutrient loading on nearshore phytoplankton populations in northern Lake Huron, we collected phytoplankton from a small, nearshore water intake at Hammond Bay four times per week from August 1973 to July 1975. Phytoplankton density, taxonomic composition, and biomass in the nearshore waters followed predictable, seasonal fluctuations during each of two 12-month periods. The density of total phytoplankton was high (450600 cells/mL) in June and low (60 to 210 cells/mL) from January to April each year. The mean annual composition of the phytoplankton assemblage by number for the study period was 33% cryptomonads, 24% diatoms, 16% chrysophytes, 16% blue-green algae, and 10% green algae. Phytoplankton biomass was low through each year (range, 0.09 to 0.66 g/m3), resembling values previously reported from Lake Superior. Pennate diatoms contributed 60 to 80% of the total biomass from December to April and in July. Phytoflagellates consisting of chrysophytes and cryptomonads accounted for 35% of the biomass throughout the 2-year study.

  10. Groupthink, Bay of Pigs, and Watergate Reconsidered.

    Science.gov (United States)

    Raven

    1998-02-01

    Irving Janis's concept of groupthink can be seen in the context of our on-again-off-again love affair with groups. Group decisions have often been seen as offering the benefits of collective wisdom, but may also lead to disastrous consequences. Groupthink then focuses on the negative effects of erroneous group decisions. Two major examples of groupthink are reexamined and compared: the disastrous Bay of Pigs decision by the elite advisory group of President Kennedy, and the advisory groups of President Nixon, which led to the Watergate disaster and at unsuccessful attempts to cover up. In both, it is suggested there was a "runaway norm," escalation and polarization with the norm being to exceed other members of the group in taking more extreme and unrestrained actions against an "enemy." While Janis seems to suggest that groupthink will ultimately lead the group to fail in its ultimate endeavors, we need to consider the frightening possibility that in the case of the Nixon group, the group actions came close to being successful. Copyright 1998 Academic Press.

  11. Recent Results from the Daya Bay Experiment

    Science.gov (United States)

    Yu, Z. Y.; Daya Bay Collaboration

    2017-09-01

    The Daya Bay reactor neutrino experiment was designed to precisely measure the neutrino oscillation parameter θ 13 via the relative comparison of neutrino rates and spectra at different baselines. Eight identically designed detectors were deployed in two near experimental halls and a far hall. Six 2.9 GWth nuclear power reactors served as intense {\\bar ν _e} sources. Since Dec. 2011, the experiment has been running stably. The latest neutrino oscillation results were based on 1230 days of data. Analysis using a three-flavor oscillation model yielded sin22θ 13 = 0.0841 ± 0.0027(stat.) ± 0.0019(syst.), and effective neutrino mass-squared difference ≤ft| {Δ mee^2} \\right| = ≤ft( {2.50 +/- 0.06≤ft( {stat.} \\right) +/- 0.06≤ft( {syst.} \\right)} \\right) × {10 - 3}e{V^2}. Besides, results from the absolute measurement of reactor {\\bar ν _e} flux and energy spectrum, and a search for a light sterile neutrino are also presented.

  12. Assessing marsh response from sea‐level rise applying local site conditions: Humboldt Bay National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Humboldt Bay National Wildlife Refuge (NWR) is located on Humboldt Bay in northern California. Humboldt Bay NWR was established in 1971 and consists of a mosaic...

  13. Abundance patterns of macrofauna and infauna in nursery habitats of Christmas Bay, Texas: July 1984 through June 1985.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Between July 1984 and June 1985, monthly samples were collected from marsh, seagrass, and nonvegetated habitats in Christmas Bay and West Bay in the Galveston Bay...

  14. A comparison of levels of bat flight and foraging activity at 10 meters and 30 meters above drained Carolina bays and reference bays, prior to bay restoration.

    Energy Technology Data Exchange (ETDEWEB)

    Menzel, Michael, A.; Ford, W., Mark; Edwards, John, W.; Kilgo, John, C.

    2001-08-01

    A technical report of a monitoring study of bat flight and foraging activity above drained and undrained Carolina bays at the Savannah River Site (SRS), located near Aiken, South Carolina. In order to determine if the vegetational community type or structure of the forest community surrounding the bays affected bat activity levels, bat activity was monitored over 3 drained and 3 undrained reference bays surrounded by pine/mixed hardwood communities and 3 drained and 3 undrained reference bays surrounded by pine monocultures. Bat activity was monitored using time expansion bat detectors. Calls were recorded to Sony Professional tape recorders (Sony WMD3). Detectors positioned at 10 m heights were linked directly to the tape recorders. Time expansion radiomicrophones were used to monitor activity at 30 m heights. The radiomicrophones were attached to 2-m diameter helium balloons and suspended approximately 30 m above the forest floor. Calls detected by the radiomicrophones were transmitted via a FM narrowband frequency to a scanner on the ground.

  15. Proceedings of the Fourth Glacier Bay Science Symposium

    Science.gov (United States)

    Piatt, John F.; Gende, Scott M.

    2007-01-01

    Foreword Glacier Bay was established as a National Monument in 1925, in part to protect its unique character and natural beauty, but also to create a natural laboratory to examine evolution of the glacial landscape. Today, Glacier Bay National Park and Preserve is still a place of profound natural beauty and dynamic landscapes. It also remains a focal point for scientific research and includes continuing observations begun decades ago of glacial processes and terrestrial ecosystems. In recent years, research has focused on glacial-marine interactions and ecosystem processes that occur below the surface of the bay. In October 2004, Glacier Bay National Park convened the fourth in a series of science symposiums to provide an opportunity for researchers, managers, interpreters, educators, students and the general public to share knowledge about Glacier Bay. The Fourth Glacier Bay Science Symposium was held in Juneau, Alaska, rather than at the Park, reflecting a desire to maximize attendance and communication among a growing and diverse number of stakeholders interested in science in the park. More than 400 people attended the symposium. Participants provided 46 oral presentations and 41 posters covering a wide array of disciplines including geology, glaciology, oceanography, wildlife and fisheries biology, terrestrial and marine ecology, socio-cultural research and management issues. A panel discussion focused on the importance of connectivity in Glacier Bay research, and keynote speakers (Gary Davis and Terry Chapin) spoke of long-term monitoring and ecological processes. These proceedings include 56 papers from the symposium. A summary of the Glacier Bay Science Plan-itself a subject of a meeting during the symposium and the result of ongoing discussions between scientists and resource managers-also is provided. We hope these proceedings illustrate the diversity of completed and ongoing scientific studies, conducted within the Park. To this end, we invited all

  16. Documenting ice in the Bay of Fundy, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, R. [Resource Manage Inc., Halifax, NS (Canada); Baddour, E. [National Research Council of Canada, St. John' s, NL (Canada). Inst. for Ocean Technology

    2006-03-15

    This paper examined the distribution of sea ice in targeted tidal energy sites in the Bay of Fundy. The Bay of Fundy in Nova Scotia is considered to be the most energetic tidal power site in North America. The study showed that the Minas Passage, the Minas Channel, Cape Enrage, Shepody Bay, the Cumberland Basin, and Cobequid Bay all periodically experience 30 per cent ice cover that is at least 15 cm thick in floes of approximately 100 meters in length. The ice floes typically move under the influence of tidal currents and sustained winds exceeding 50 mph. During severe winters, some sites experience 70 per cent cover, with ice greater than 30 cm thick. Approximately 90 per cent of the harvestable tidal current energy sites in the Bay of Fundy and New Brunswick experience sea ice capable of impacting marine operations. It was concluded that tidal current harvesting devices in these sites should be designed to tolerate severe sea-ice conditions in order to harvest the global resources of this alternative energy source. Additional research is needed to further characterize tidal currents in the presence of ice. 24 refs., 13 figs.

  17. A Bayes factor meta-analysis of Bem's ESP claim.

    Science.gov (United States)

    Rouder, Jeffrey N; Morey, Richard D

    2011-08-01

    In recent years, statisticians and psychologists have provided the critique that p-values do not capture the evidence afforded by data and are, consequently, ill suited for analysis in scientific endeavors. The issue is particular salient in the assessment of the recent evidence provided for ESP by Bem (2011) in the mainstream Journal of Personality and Social Psychology. Wagenmakers, Wetzels, Borsboom, and van der Maas (Journal of Personality and Social Psychology, 100, 426-432, 2011) have provided an alternative Bayes factor assessment of Bem's data, but their assessment was limited to examining each experiment in isolation. We show here that the variant of the Bayes factor employed by Wagenmakers et al. is inappropriate for making assessments across multiple experiments, and cannot be used to gain an accurate assessment of the total evidence in Bem's data. We develop a meta-analytic Bayes factor that describes how researchers should update their prior beliefs about the odds of hypotheses in light of data across several experiments. We find that the evidence that people can feel the future with neutral and erotic stimuli to be slight, with Bayes factors of 3.23 and 1.57, respectively. There is some evidence, however, for the hypothesis that people can feel the future with emotionally valenced nonerotic stimuli, with a Bayes factor of about 40. Although this value is certainly noteworthy, we believe it is orders of magnitude lower than what is required to overcome appropriate skepticism of ESP.

  18. Causal Bayes Model of Mathematical Competence in Kindergarten

    Directory of Open Access Journals (Sweden)

    Božidar Tepeš

    2016-06-01

    Full Text Available In this paper authors define mathematical competences in the kindergarten. The basic objective was to measure the mathematical competences or mathematical knowledge, skills and abilities in mathematical education. Mathematical competences were grouped in the following areas: Arithmetic and Geometry. Statistical set consisted of 59 children, 65 to 85 months of age, from the Kindergarten Milan Sachs from Zagreb. The authors describe 13 variables for measuring mathematical competences. Five measuring variables were described for the geometry, and eight measuring variables for the arithmetic. Measuring variables are tasks which children solved with the evaluated results. By measuring mathematical competences the authors make causal Bayes model using free software Tetrad 5.2.1-3. Software makes many causal Bayes models and authors as experts chose the model of the mathematical competences in the kindergarten. Causal Bayes model describes five levels for mathematical competences. At the end of the modeling authors use Bayes estimator. In the results, authors describe by causal Bayes model of mathematical competences, causal effect mathematical competences or how intervention on some competences cause other competences. Authors measure mathematical competences with their expectation as random variables. When expectation of competences was greater, competences improved. Mathematical competences can be improved with intervention on causal competences. Levels of mathematical competences and the result of intervention on mathematical competences can help mathematical teachers.

  19. Phytoplankton and nutrient dynamics in Winyah Bay, SC.

    Science.gov (United States)

    Boneillo, G. E.; Brooks, S. S.; Brown, S. L.; Woodford, K. M.; Wright, C. R.

    2016-02-01

    Winyah Bay is a coastal plain estuary located in South Carolina that has been classified for a moderate risk of Eutrophication by NOAA. Winyah Bay receives freshwater input from four rivers, the Waccamaw, Sampit, Black, and Pee Dee Rivers. The Waccamaw, Sampit and Black River are blackwater systems that discharge elevated amounts of colored dissolved organic matter. During the summer and fall of 2015, bioassay experiments were performed to simultaneously examine both light and nutrient (nitrogen & phosphate) limitation throughout Winyah Bay. Sampling stations near the mouth of the Waccamaw and Sampit Rivers showed that phytoplankton were light limited in the late summer instead of nutrient limited. These stations were located in the industrialized area of the bay and typically had the highest nutrient concentrations and highest turbidity, with Secchi depths typically less than 0.5 meters. Results indicated that phytoplankton may be nitrogen limited near the mouth of Winyah Bay, where nutrient concentrations and turbidity were observed to be lower than locations further upstream. There was also an observed dissolved oxygen and pH gradient during the summer of 2015. Dissolved oxygen levels less than 4.0 mg/L were routinely observed near the industrialized head of the estuary and corresponded with lower pH values.

  20. A model for the geomorphology of the Carolina Bays

    Science.gov (United States)

    Zamora, Antonio

    2017-04-01

    Geometrical analysis of the Carolina Bays using Google Earth in combination with LiDAR data makes it possible to postulate that the bays formed as the result of impacts, rather than from eolian and lacustrine processes. The Carolina Bays are elliptical conic sections with width-to-length ratios averaging 0.58 that are radially oriented toward the Great Lakes region. The radial distribution of ejecta is one characteristic of impacts, and the width-to-length ratios of the ellipses correspond to cones inclined at approximately 35°, which is consistent with ballistic trajectories from the point of convergence. These observations, and the fact that these geomorphological features occur only on unconsolidated soil close to the water table, make it plausible to propose that the Carolina Bays are the remodeled remains of oblique conical craters formed on ground liquefied by the seismic shock waves of secondary impacts of glacier ice boulders ejected by an extraterrestrial impact on the Laurentide Ice Sheet. Mathematical analysis using ballistic equations and scaling laws relating yield energy to crater size provide clues about the magnitude of the extraterrestrial event. An experimental model elucidates the remodeling mechanisms and provides an explanation for the morphology and the diverse dates of the bays.